CN117795982A - Film for acoustic member - Google Patents
Film for acoustic member Download PDFInfo
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- CN117795982A CN117795982A CN202280054653.0A CN202280054653A CN117795982A CN 117795982 A CN117795982 A CN 117795982A CN 202280054653 A CN202280054653 A CN 202280054653A CN 117795982 A CN117795982 A CN 117795982A
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- Prior art keywords
- film
- layer
- acoustic member
- less
- silicone
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Landscapes
- Manufacture Of Macromolecular Shaped Articles (AREA)
- Diaphragms For Electromechanical Transducers (AREA)
- Laminated Bodies (AREA)
Abstract
A single-layer film for acoustic members, which has curability. According to the present invention, it is possible to provide a film for an acoustic member capable of improving shape retention before molding, formability during molding, and follow-up performance to a mold, preventing the film from adhering to the mold such as a metal mold during molding, and peeling the release film from the release film without breakage when peeling the release film before molding.
Description
Technical Field
The present invention relates to a film for an acoustic member, a diaphragm, an acoustic transducer, a method for producing a film for an acoustic member, a silicone film, a molded article, a method for producing a silicone film, a method for producing a film, a method for producing an acoustic member, and a method for using a film for an acoustic member.
Background
With the popularization of small electronic devices such as smart phones, PDAs, notebook computers, DVDs, liquid crystal televisions, digital cameras, and portable music devices, the demand for small speakers (commonly referred to as micro speakers), small receivers, and further small electroacoustic transducers such as microphones and headphones for use in these electronic devices is increasing. As the vibration plate used in these electroacoustic transducers, polyetherimide (PEI) resin, polyether ether ketone (PEEK) resin, or the like is widely used.
In addition, in recent years, the use of silicone resins for the above-described vibration plate has also been studied. For example, patent document 1 discloses a vibration plate sheet in which a release sheet, a 1 st layer formed of an uncured liquid silicone composition, and a 2 nd layer mainly containing thermoplastic polyurethane are laminated in this order, and a method for manufacturing a vibration plate using the vibration plate sheet. In patent document 1, a vibration plate is manufactured by providing a vibration plate sheet in a mold, molding the sheet, and then peeling the release sheet from the molded product. Since the sheet for a vibration plate described in patent document 1 uses an uncured liquid silicone composition, the shaping property at the time of shaping can be improved, and the follow-up property to a metal mold can be improved.
Prior art literature
Patent literature
Patent document 1: japanese patent laid-open No. 2018-152817
Disclosure of Invention
Problems to be solved by the invention
In patent document 1, a sheet for a vibration plate is formed by being placed in a mold while a release film is laminated on a layer 1 formed of an uncured liquid silicone composition. Therefore, it is necessary to peel the release film after molding, but the release film is often difficult to peel from layer 1 due to heating and pressing during molding, and the workability is low, which makes mass production difficult.
Therefore, the sheet for a vibration plate is desirably set in a mold such as a metal mold after the release film is peeled off. However, if the release film is not provided, the 1 st layer formed of the uncured liquid silicone composition adheres to the mold, and there is a problem that the molded article cannot be easily removed from the mold. In addition, when the release film is peeled off, there is a problem that the 1 st layer formed of the uncured liquid silicone composition is broken. In the vibration plate sheet of patent document 1, if the release film is not provided, the shape retention before shaping is also low.
Accordingly, the problem of claim 1 of the present invention is to provide a film for acoustic members, which can improve the formability during forming and the follow-up ability to a mold, and can be peeled from the release film without breakage when the release film is peeled before forming.
Further, the object of claim 2 of the present invention is to provide a silicone film which can improve shape retention before molding and formability during molding and can prevent the film from sticking to a mold during molding.
Further, the problem of claim 3 of the present invention is to provide a film for an acoustic member, which has shape retention before molding, formability during molding, and follow-up ability to a mold, and which can be peeled from the release film without breakage when the release film is peeled before molding.
Further, the problem of claim 4 of the present invention is to provide a film which can improve shape retention before molding, formability during molding, and follow-up ability to a die, and can prevent the film from sticking to a die such as a metal die during molding.
Solution for solving the problem
The present inventors have conducted intensive studies and as a result, have found that the above problems can be solved by a film for an acoustic member having a single layer which is curable, a single layer of a silicone film having a cured property and having a coefficient of static friction of at least one surface thereof controlled, a film having a specific storage modulus, or a film having a cured intermediate layer by controlling the coefficient of static friction of the outermost layer and the innermost layer in addition to forming the film into a multilayer structure, and have completed the present invention. The gist of the present invention is as follows.
[1] A single-layer film for acoustic members, which has curability.
[2] The film for an acoustic member according to item [1], wherein the gel fraction is 60% or more and 90% or less.
[3] The film for an acoustic member according to the above [1] or [2], which has the following viscoelastic properties (a).
(a) The storage modulus E' at a measurement temperature of 20 ℃ is not less than 0.1MPa and not more than 500 MPa.
[4] The film for an acoustic member according to any one of [1] to [3], which has thermosetting properties.
[5] The film for an acoustic member according to any one of [1] to [4], which has a crosslinked structure.
[6] The film for an acoustic member according to any one of [1] to [5], which has the following viscoelastic properties (b) to (d) in a cured state.
(b) Determination of storage modulus E 'at 20℃' 20 Is 0.1MPa to 500 MPa.
(c) Determination of storage modulus E 'at 100℃' 100 Is 0.1MPa to 500 MPa.
(d) The storage modulus E' 100 Relative to the storage modulus E' 20 Ratio (E ')' 100 /E’ 20 ) Is 0.2 to 1.0.
[7] The membrane for an acoustic member according to any one of [1] to [6], which is a membrane for a diaphragm.
[8] The film for an acoustic member according to any one of [1] to [7], which is a silicone film.
[9] The film for an acoustic member according to any one of [1] to [8], wherein a static friction coefficient of at least one surface is 3 or less.
[10] An acoustic member obtained by curing the film for acoustic members described in any one of [1] to [9 ].
[11] A vibration plate obtained by curing the film for an acoustic member according to any one of the above [1] to [9 ].
[12] An acoustic transducer comprising the acoustic member described in [10 ].
[13] An acoustic transducer comprising the diaphragm according to [11 ].
[14] The method for producing a film for an acoustic member according to any one of [1] to [9], which comprises a step of irradiating radiation.
[15] The method for producing a film for an acoustic member according to item [14], wherein the release film is peeled from the resin layer after irradiation of the resin layer laminated on the release film with radiation.
[16] The method for producing a film for an acoustic member according to any one of [1] to [9], comprising the steps of: laminating a resin layer between 2 release films having a surface roughness (Ra) of 0.10 to 6.00 [ mu ] m; a step of curing the laminated resin layers; and a step of peeling at least 1 release film from the cured resin layer.
[17] A single-layer silicone film having curability and a static friction coefficient of at least one surface of 3 or less.
[18] The silicone film according to item [17], wherein the gel fraction is 60% or more and 90% or less.
[19] The silicone film according to the above [17] or [18], which has the following viscoelastic properties (a).
(a) The storage modulus E' at a measurement temperature of 20 ℃ is not less than 0.1MPa and not more than 500 MPa.
[20] The silicone film according to any one of the above [17] to [19], which has thermosetting properties.
[21] The silicone film according to any one of the above [17] to [20], which has a crosslinked structure.
[22] The silicone film according to any one of [17] to [21], which has the following viscoelastic properties (b) to (d) in a cured state.
(b) Determination of storage modulus E 'at 20℃' 20 Is 0.1MPa to 500MPa
(c) Determination of storage modulus E 'at 100℃' 100 Is 0.1MPa to 500 MPa.
(d) The storage modulus E' 100 Relative to the storage modulus E' 20 Ratio (E ')' 100 /E’ 20 ) Is 0.2 to 1.0.
[23] The silicone film according to any one of the above [17] to [22], which is a film for an acoustic member.
[24] The silicone film according to any one of the above [17] to [23], which is a film for a vibration plate.
[25] An organosilicon film with a release film, comprising: the silicone film of any one of [17] to [24], and a release film provided on at least one side of the silicone film.
[26] A molded article obtained by curing the silicone film of any one of the above [17] to [24 ].
[27] An acoustic member obtained by curing the silicone film described in any one of [17] to [24 ].
[28] A vibration plate obtained by curing the silicone film of any one of the above [17] to [24 ].
[29] An acoustic transducer comprising the acoustic member described in [27 ].
[30] An acoustic transducer comprising the diaphragm according to [28 ].
[31] The method for producing a silicone film according to any one of [17] to [24], which comprises a step of irradiating with radiation.
[32] The method for producing a silicone film according to item [31], wherein the silicone resin layer laminated on the release film is irradiated with radiation, and then the release film is peeled from the silicone resin layer.
[33] The method for producing a silicone film according to any one of the above [17] to [24], comprising the steps of: a step of laminating a silicone resin layer between 2 release films having a surface roughness (Ra) of 0.10 to 6.00 [ mu ] m; a step of curing the laminated silicone resin layers; and a step of peeling at least 1 release film from the cured silicone resin layer.
[34] A film for an acoustic member, which is a film having curability and has the following viscoelastic properties (a).
(a) The storage modulus E' at a measurement temperature of 20 ℃ and a frequency of 10Hz is not less than 0.1MPa and not more than 500 MPa.
[35] The film for an acoustic member according to item [34] above, which has thermosetting properties.
[36] The film for an acoustic member according to [34] or [35], which has a crosslinked structure.
[37] The film for an acoustic member according to any one of [34] to [36], having a gel fraction of 90% or less.
[38] The film for an acoustic member according to any one of [34] to [37], which is a silicone film.
[39] The film for an acoustic member according to any one of [34] to [38], which has the following viscoelastic properties (b) to (d) in a cured state.
(b) Determination of storage modulus E 'at 20℃and frequency 10 Hz' 20 Is 0.1MPa to 500 MPa.
(c) Determination of storage modulus E 'at a temperature of 100℃and a frequency of 10 Hz' 100 Is 0.1MPa to 500 MPa.
(d) E 'above' 100 /E’ 20 0.4 to 1.0.
[40] A film for an acoustic member with a release film, comprising: the film for an acoustic member according to any one of [34] to [39], and a release film provided on at least one side of the film for an acoustic member.
[41] An acoustic member obtained by curing the film for acoustic members described in any one of [34] to [40 ].
[42] An acoustic transducer comprising the acoustic member described in [41 ].
[43] The method for producing a film for an acoustic member according to any one of [34] to [39], comprising a step of curing at least a part of 1 or more resin layers constituting the film.
[44] The method for producing a film for an acoustic member according to item [43], which comprises a step of laminating a cured resin layer and a resin layer having curability.
[45] A film, comprising: the resin composition comprises a top layer and a bottom layer of a cured resin layer, and at least 1 curable intermediate layer disposed between the top layer and the bottom layer, wherein the top layer and the bottom layer have a static friction coefficient of 3 or less.
[46] The film according to [45], wherein the gel fraction is 0% or more and 90% or less.
[47] The film according to [45] or [46], wherein the gel fraction of the outermost layer and the innermost layer is 80% or more.
[48] The film according to any one of the above [45] to [47], which has the following viscoelastic properties (a).
(a) The storage modulus E' at the measurement temperature of 20 ℃ is not less than 0.1MPa and not more than 500 MPa.
[49] The film according to any one of the above [45] to [48], which has thermosetting properties.
[50] The film according to any one of [45] to [49], which has a crosslinked structure.
[51] The film according to any one of the above [45] to [50], which is a silicone film.
[52] The film according to any one of [45] to [51], which has the following viscoelastic properties (b) in a cured state.
(b) Measuring temperatureStorage modulus E 'at 20℃' 20 Is 0.1MPa or more.
[53] The film according to any one of [45] to [52], which has the following viscoelastic properties (c) to (e) in a cured state.
(c) Determination of storage modulus E 'at 20℃' 20 Is 0.1MPa to 500 MPa.
(d) Determination of storage modulus E 'at 100℃' 100 Is 0.1MPa to 500 MPa.
(e) The storage modulus E' 100 Relative to the storage modulus E' 20 Ratio (E ')' 100 /E’ 20 ) Is 0.4 to 1.0.
[54] The film according to any one of [45] to [53], which is a film for an acoustic member.
[55] The film according to any one of [45] to [54], which is a film for a vibration plate.
[56] A film with a release film, comprising: the film of any one of [45] to [55], and a release film provided on at least one side of the film.
[57] An acoustic member obtained by curing the film of any one of [45] to [55 ].
[58] A vibration plate obtained by curing the film of any one of the above [45] to [55 ].
[59] An acoustic transducer comprising the acoustic member described in [57 ].
[60] An acoustic transducer comprising the diaphragm described in [58 ].
[61] The method for producing a film according to any one of [45] to [55], which comprises a step of laminating an uncured or semi-cured intermediate layer between the cured outermost layer and the cured innermost layer.
[62] A method for producing an acoustic member, wherein the film for an acoustic member described in any one of [1] to [9], the silicone film described in any one of [17] to [24], the film for an acoustic member described in any one of [34] to [39], or the film described in any one of [45] to [55] is molded by a mold.
[63] The method of manufacturing an acoustic member according to item [62], comprising the step of heating the film before disposing the film in the mold.
[64] The method for producing an acoustic member according to [62] or [63], wherein the heating temperature at the time of shaping is 180℃or higher and 260℃or lower.
[65] The method of producing an acoustic member according to any one of [62] to [64], wherein the shaping time is 1 second or more and 5 minutes or less.
[66] The method for producing an acoustic member according to any one of [62] to [65], wherein the acoustic member is formed by any one of press molding, vacuum molding, and pressure molding.
[67] A method for producing an acoustic member, wherein the release film is peeled from the silicone film with release film described in [25], the film for an acoustic member with release film described in [40], or the film with release film described in [56], and the silicone film is placed in a mold to shape.
[68] The method of using the film for an acoustic member of any one of the above [1] to [9], the silicone film of any one of the above [17] to [24], the film for an acoustic member of any one of the above [34] to [39], or the film of any one of the above [45] to [55 ].
[69] An acoustic member has a static friction coefficient of at least one face of 3 or less.
[70] The acoustic member according to item [69] above, which comprises a silicone film.
[71] The acoustic member according to [69] or [70], which has a thickness of 5 μm or more and 500 μm or less.
[72] The acoustic member according to any one of [69] to [71] above, having a crosslinked structure.
[73] The acoustic member according to any one of [69] to [72], having the following viscoelastic properties (b) to (d).
(b) Determination of storage modulus E 'at 20℃' 20 Is 0.1MPa to 500MPa
(c) Determination of storage modulus E 'at 100℃' 100 Is 0.1MPa to 500 MPa.
(d) The storage modulus E' 100 Relative to the storage modulus E' 20 Ratio (E ')' 100/ E’ 20 ) Is 0.2 to 1.0.
ADVANTAGEOUS EFFECTS OF INVENTION
According to the present invention, it is possible to provide a film for an acoustic member, which can improve the formability during forming and the follow-up performance to a mold, and can be peeled from the release film without breakage when the release film is peeled before forming. (mode 1 of the invention).
Further, it is possible to provide a silicone film which can improve shape retention before molding and formability during molding and can prevent the film from sticking to a mold during molding (claim 2 of the present invention).
Further, a film for an acoustic member is provided which has shape retention before molding, formability during molding, and follow-up property to a mold, and can be peeled from the release film without breakage when the release film is peeled before molding (claim 3 of the present invention).
Further, a film is provided which can improve shape retention before molding, formability during molding, and follow-up property of a mold, and can prevent the film from adhering to the mold such as a metal mold during molding (claim 4 of the present invention).
Drawings
Fig. 1 is a cross-sectional view showing the structure of a micro-speaker diaphragm 1 according to an embodiment of the present invention.
Fig. 2 is a cross-sectional view showing the structure of a micro-speaker diaphragm 11 according to another embodiment of the present invention.
Fig. 3 is a plan view showing a structure of a micro-speaker diaphragm 21 according to still another embodiment of the present invention.
Detailed Description
Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the embodiments described below as long as the gist of the present invention is not exceeded.
In the present invention, the film is regarded as including the sheet since the boundary between the film and the sheet is not defined.
[ mode 1 of the invention ]
In accordance with embodiment 1 of the present invention, a single-layer film for acoustic members is provided, which has curability.
< film for Acoustic Member >
The film for acoustic members (hereinafter, sometimes referred to as "the present film (1)") of the present invention is a film having curability and being a single layer and suitable for acoustic members.
The film (1) has curability and at least a part of uncured portion, and thus has formability, and is a single layer, so that there is no problem of delamination between layers.
< gel fraction >
The gel fraction of the film (1) is preferably 60% to 90%. When the gel fraction is within this range, the effect of the present invention is exhibited by the surface layer portion being moderately cured and the inside being uncured or semi-cured. From the above viewpoints, the gel fraction of the present film (1) is more preferably 60% or more and 85% or less, and still more preferably 65% or more and 80% or less.
The gel fraction was measured by the method described in examples.
Viscoelastic Properties (storage modulus)
The present film (1) preferably has the following viscoelastic properties (a).
(a) The storage modulus E' at a measurement temperature of 20 ℃ and a frequency of 10Hz is not less than 0.1MPa and not more than 500 MPa.
When the storage modulus E' is 0.1MPa or more, the film (1) is of a type laminated on a release film, and the film (1) has a suitable hardness, so that the film is easily peeled from the release film, and breakage during peeling is not a concern. In addition, the shape can be maintained even after the release film is peeled off. On the other hand, when the storage modulus E' is 500MPa or less, the film has appropriate flexibility, and the film has excellent follow-up property to a mold and shape-forming property during molding.
From the above viewpoints, E' is preferably 0.5MPa or more and 300MPa or less, more preferably 0.8MPa or more and 200MPa or less, still more preferably 1.0MPa or more and 100MPa or less, still more preferably 1.2MPa or more and 10MPa or less, and particularly preferably 1.5MPa or more and 5MPa or less.
The present film (1) preferably has the following viscoelastic properties (b) to (d) in a cured state.
(b) Determination of storage modulus E 'at 20℃and frequency 10 Hz' 20 Is 0.1MPa to 500 MPa.
(c) Determination of storage modulus E 'at a temperature of 100℃and a frequency of 10 Hz' 100 Is 0.1MPa to 500MPa
(d) E 'above' 100 /E’ 20 Is 0.2 to 1.0.
(b) Determination of storage modulus E 'at 20℃and frequency 10 Hz' 20 When the pressure is 0.1MPa or more, the cured product has a certain hardness, and thus the handleability after curing is improved. On the other hand, if E' 20 When the pressure is 500MPa or less, the film (1) tends to have excellent acoustic properties such as sound quality and reproducibility of the diaphragm when used as the diaphragm. From the viewpoints of acoustic characteristics and handleability after curing, storage modulus E 'at 20℃after curing' 20 More preferably 1MPa to 400MPa, still more preferably 2MPa to 200MPa, still more preferably 3MPa to 50MPa, particularly preferably 4MPa to 10 MPa.
In addition, (c) the storage modulus E 'at a temperature of 100℃and a frequency of 10Hz was measured' 100 When the pressure is 0.1MPa or more and 500MPa or less, heat resistance is excellent, and excellent acoustic characteristics can be expected even in a high-temperature environment. From the standpoint of acoustic characteristics and handleability after curing, storage modulus E' 100 More preferably 1MPa to 400MPa, still more preferably 2MPa to 200MPa, still more preferably 3MPa to 3MPa50MPa or less, particularly preferably 3.5MPa or more and 10MPa or less.
In addition, by making the ratio of storage modulus (d) (E' 100 /E’ 20 ) When the elastic modulus is in the range of 0.2 to 1.0, the change in elastic modulus due to the temperature change tends to be small, and the heat resistance tends to be good. Further, since the change in elastic modulus upon heating is small, the sound quality in a high-temperature environment is not easily lowered, and the reproducibility of sound from a low-temperature region to a high-temperature region is easily maintained to be excellent.
From the above point of view, the above ratio (E' 100 /E’ 20 ) More preferably from 0.25 to 0.99, still more preferably from 0.3 to 0.97, still more preferably from 0.35 to 0.95.
The storage modulus was obtained by curing the material by a simple method of press molding with 2 flat plates under a pressure of 0.2MPa while heating at 200 ℃ for 2 minutes, and by the method described in the examples.
Coefficient of static friction >
The film (1) preferably has a static friction coefficient of at least one surface of 3 or less. By setting the static friction coefficient to 3 or less, the film handling properties are improved, for example, in the case of a release film with a release film, peeling from the release film is facilitated, and breakage during peeling is not a concern. In addition, the film is easily peeled from the mold, and the film can be prevented from adhering to the mold during molding. From the above viewpoints, the static friction coefficient is preferably 2.8 or less, more preferably 2.5 or less, further preferably 2.3 or less, and particularly preferably 2.1 or less. The lower limit of the static friction coefficient is not particularly limited, and may be, for example, 0.3 or more, 0.5 or more, or 0.7 or more. The coefficient of static friction is required to be 3 or less on at least one surface of the present film (1), but the coefficient of static friction on the other surface may be more than 3 or equal to 3.
The static friction coefficient is a value measured on a stainless steel plate (SUS 430), and is a value obtained by the method described in examples.
The static friction coefficient can be suitably adjusted by a film forming method, a film material, a surface portion gel fraction, and the like.
Specifically, by appropriately adjusting the surface shape, the coefficient of static friction can be adjusted, and for example, by imparting roughness to the surface portion, the coefficient of static friction can be reduced. Examples of the method for adjusting the static friction coefficient include a method for imparting irregularities by various methods such as sand blasting, shot blasting, etching, engraving, embossing roll transfer, embossing belt transfer, embossing film transfer, and surface crystallization. The surface shape can also be changed by adding particles to the film, thereby adjusting the static friction coefficient.
As a specific embodiment, a film having a static friction coefficient of 3 or less can be produced by laminating or extruding a resin composition for forming the present film (1) onto a release film having irregularities on the surface thereof and forming the film into a film shape, and irradiating the film with radiation from the release film side to crosslink the surface layer portion as described above, and transferring the irregularities of the release film.
Stretch elongation at break >
In the cured state, the tensile elongation at break of the film (1) is preferably 100% or more, more preferably 200% or more, and still more preferably 300% or more. If the tensile elongation at break is within this range, the toughness of the film becomes high, and breakage due to vibration over a long period of time is less likely to occur, and durability when used in an acoustic member such as a diaphragm tends to be excellent. The higher the tensile elongation at break, the better, and the upper limit is not particularly limited, but is usually 1500% or less.
The tensile elongation at break was measured by the method according to JIS K7161:2014, and measuring elongation at break of the cured film (1) at a stretching speed of 200 mm/min at 23 ℃ in TD (direction perpendicular to the flow direction of the resin).
The film (1) is a film having curability, and may be any of photocurability, moisture curability, thermosetting, and the like as the type of curing, but is preferably thermosetting. The film (1) has thermosetting properties, and can be cured when shaping is performed while heating, so that the shaping property is better. Since the film (1) has curability, the gel fraction increases by a curing treatment such as heating.
The present film (1) preferably has a crosslinked structure. By having a moderately crosslinked structure, a film having suitable viscoelastic properties upon crosslinking curing can be easily obtained. In addition, the shape retention before curing (i.e., before molding) is easily improved.
The film (1) may be in a state in which the surface portion is crosslinked and the inside is not cured, but in view of flexibility of the film, follow-up property to a mold at the time of molding, and formability, it is preferable that the film as a whole has a proper degree of crosslinking. That is, the film as a whole is preferably a film which is harder than the uncrosslinked film and softer than the fully cured film.
In the present invention, the presence or absence of a crosslinked structure can be identified by the presence of an unreacted crosslinking agent and a post-reaction (decomposed) crosslinking agent contained in a trace amount in the film in the case of a condensed type, and by the presence of a vinyl group participating in a crosslinking reaction in the case of an addition type.
The thickness of the film (1) is not particularly limited, but is preferably 5 μm or more and 500 μm or less, more preferably 15 μm or more and 400 μm or less, and still more preferably 30 μm or more and 300 μm or less. If the thickness of the film is within this range, a film with less thickness fluctuation in the film manufacturing process can be manufactured, and for example, a molded article suitable for the thickness of the vibration plate can be manufactured.
The film (1) is composed of a resin layer, and the resin constituting the resin layer is preferably a curable resin, more preferably a thermosetting resin. Among them, preferable specific examples include epoxy resins, polyurethane resins, silicone resins, acrylic resins, phenolic resins, unsaturated polyester resins, polyimide resins, melamine resins, and the like. These resins may be used alone or in combination of 1 or more than 2.
The present film (1) is preferably a silicone film. When the film (1) is a silicone film, heat resistance, mechanical strength, and the like are excellent, and the viscoelastic properties (a) and (b) to (d) are easily satisfied. In addition, the tensile elongation at break is also easily adjusted within the above-described desired range.
Organic silicon film-
The silicone polymer (organopolysiloxane) used in the silicone film has, for example, a structure represented by the following formula (I).
R n SiO (4-n)/2 ···(I)
Here, R may be the same or different and is a substituted or unsubstituted monovalent hydrocarbon group, preferably a monovalent hydrocarbon group having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, and n is a positive number of 1.95 to 2.05.
R may be, for example, as follows: alkyl groups such as methyl, ethyl, propyl, butyl, hexyl, and dodecyl; cycloalkyl groups such as cyclohexyl; alkenyl groups such as vinyl, allyl, butenyl, and hexenyl; aryl groups such as phenyl and tolyl; aralkyl groups such as beta-phenylpropyl; and chloromethyl, trifluoropropyl, cyanoethyl, and the like, in which part or all of the hydrogen atoms bonded to carbon atoms of these groups are substituted with halogen atoms, cyano groups, and the like.
The organopolysiloxane of the present invention is preferably terminated at the molecular chain end with trimethylsilyl group, dimethylvinyl group, dimethylhydroxysilyl group, trivinylsilyl group, or the like. Furthermore, the organopolysiloxane preferably has at least 2 alkenyl groups in the molecule. Specifically, R preferably has an alkenyl group of 0.001 mol% or more and 5 mol% or less, preferably 0.005 mol% or more and 3 mol% or less, more preferably 0.01 mol% or more and 1 mol% or less, particularly preferably 0.02 mol% or more and 0.5 mol% or less, and particularly preferably has a vinyl group. The organopolysiloxane is substantially linear, but may also be partially branched. In addition, the compound may be a mixture of 2 or more kinds of compounds having different molecular structures.
The resin composition for forming the silicone film is preferably of a kneading type (mill) containing an organopolysiloxane. The kneaded resin composition is in a non-liquid state (e.g., solid or paste) without flowing at room temperature (25 ℃) in an uncured state (e.g., uncured state before irradiation with radiation), but can be uniformly mixed by a kneader described later.
The resin composition for forming the silicone film may be mixed with a resin other than a silicone resin (organopolysiloxane) as a resin.
The organopolysiloxane may be commercially available, or may be commercially available containing a mixture of additives such as a cerium oxide filler and a silica filler in addition to the organopolysiloxane. Specifically, trade names "KE-5550-U", "KE-597-U", "KE-594-U", etc. manufactured by Xinyue chemical industries, inc. may also be used.
Radiation ray
The silicone film is preferably formed into a semi-crosslinked structure, and is suitably formed by irradiation with radiation.
The radiation is not particularly limited as long as it exhibits the effect of the present invention, and examples thereof include X-rays, γ -rays, electron rays, β -rays, α -rays, protons, deuterons, heavy ions, neutron rays, and meson rays.
The radiation dose and the irradiation time of the radiation are desirably adjusted so as to conform to the above-described range of the gel fraction and/or storage modulus according to the type of the radiation.
(crosslinking agent)
In the resin composition for forming a silicone film, a crosslinking agent may be compounded in addition to the above-described organopolysiloxane, with an organic peroxide being preferably compounded. By compounding the organic peroxide, the silicone film can be easily cured in the subsequent shaping and the like.
In view of flexibility of the film, follow-up property to a mold at the time of molding, and shaping property, a film having a proper degree of crosslinking is preferable. That is, as the hardness, a film that is harder than the uncrosslinked film and softer than the fully cured film is preferable. For example, the gel fraction may be semi-cured so as to fall within a desired range.
Examples of the organic peroxide include: organic peroxides such as dialkyl peroxides, e.g., di-t-butyl peroxide, 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexane, and 2, 5-dimethyl-2, 5-bis (t-butylperoxy) hexane, and aralkyl peroxides, e.g., 2, 4-dicumyl peroxide, are preferable from the viewpoints of crosslinking rate and safety, and 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexane is particularly preferable.
The blending amount of the organic peroxide in the resin composition for forming the silicone film is preferably 0.01% by mass or more and 10% by mass or less, more preferably 0.03% by mass or more and 5% by mass or less, still more preferably 0.05% by mass or more and 4% by mass or less, particularly preferably 0.1% by mass or more and 3% by mass or less, and particularly preferably 0.3% by mass or more and 2% by mass or less, based on the total amount of the resin composition. When the blending amount of the organic peroxide is within this range, a composition having a sufficient curing speed tends to be obtained safely.
(filling Material)
The film (1) may contain a filler. The filler may be suitably a silica such as cerium oxide (cerium oxide), fumed silica or precipitated silica. The film (1) can easily bring the mechanical properties such as storage modulus and tensile elongation at break of the film into proper ranges by containing the filler. In addition, by using the filler, the viscosity and hardness of the resin composition can be easily adjusted, and the balance between the fluidity and secondary processability of the resin composition can be easily optimized. Further, there is an advantage that the hardness can be easily adjusted appropriately according to the design and acoustic characteristics of the acoustic member.
The filler constitutes a part of the gel component in the measurement of the gel fraction, and the gel fraction of the film (1) is increased by containing the filler. The hardness of the film (1) can be improved by containing the filler to increase the gel fraction as in the case of crosslinking to increase the gel fraction.
The content of the filler in the resin composition for forming the present film (1) is, for example, 10 mass% or more and 50 mass% or less, preferably 15 mass% or more and 40 mass% or less, more preferably 20 mass% or more and 35 mass% or less, based on the total amount of the resin composition. The average particle diameter of the filler is, for example, 0.01 μm or more and 20 μm or less, preferably 0.1 μm or more and 10 μm or less, and more preferably 0.5 μm or more and 5 μm or less. The average particle diameter of the filler can be measured as the median particle diameter (D50) using a particle size distribution measuring apparatus based on a laser diffraction method or the like.
The resin composition for forming the present film (1) may contain various additives such as heat stabilizer, antioxidant, ultraviolet absorber, light stabilizer, antibacterial/antifungal agent, antistatic agent, lubricant, pigment, dye, flame retardant, impact resistance improver and the like within a range not impairing the effect.
< film with Release film >
The film (1) may be used in the form of a film with a release film. The film with a release film comprises the film (1) and a release film provided on at least one side of the film (1).
In addition, in the film with a release film, the release film is preferably provided on both sides of the present film (1).
The release film may be a resin film or a film having a release layer formed by a release treatment on at least one side of the resin film. When the release film has a release layer, the release layer may be laminated on the film (1) so as to be in contact with the film (1).
As the resin for the release film, there can be exemplified: polyolefin resins such as polypropylene, acrylic resins, polystyrene resins, polyacetal resins, polyamide resins, polyester resins, polycarbonate resins, ABS resins, polyether ether ketone resins, and the like. Among these, polyester-based resins are preferable, and among them, polyethylene terephthalate-based resins are preferable.
The thickness of the release film is not particularly limited, but is preferably 5 μm or more and 150 μm or less, more preferably 7 μm or more and 120 μm or less, still more preferably 10 μm or more and 100 μm or less, and particularly preferably 10 μm or more and 80 μm or less.
The film (1) is protected by a release film by being provided with the release film. Therefore, damage to the film (1) during transportation or the like is prevented. The release film may be used as it is when the present film (1) is produced, or may be laminated separately to the present film (1) after production.
The present film (1) is molded by, for example, shaping as described later, but may be set in a mold such as a metal mold after the release film is peeled off from the present film (1) at the time of molding. In this case, the present film (1) can be peeled off from the release film without being broken.
Method for producing the present film (1)
The film (1) can be formed by a general forming method, for example, extrusion forming or the like. The resin composition for obtaining a film may be obtained by kneading or the like as described below, and may be molded by extrusion molding or the like. In the present film (1), post-processing such as embossing may be performed on the film as described above in order to adjust the static friction coefficient of the preferred embodiment to 3 or less.
The present film (1) with a release film having a static friction coefficient of 3 or less may be obtained by laminating a resin composition between release films or on a release film by lamination molding using a release film having irregularities.
More specifically, the following methods are suitably used.
A method for producing the present film (1) (film for acoustic member) comprises the steps of: laminating a resin layer between 2 release films having a surface roughness (Ra) of 0.10 to 6.00 [ mu ] m; a step of curing the laminated resin layers; and a step of peeling at least 1 release film from the cured resin layer.
Here, the surface roughness (Ra) was measured by the method described in examples.
The resin compositions are not particularly limited, and may be obtained by kneading materials constituting the resin compositions, for example. As the kneading machine used for kneading, known kneading machines such as extruders such as single screw and twin screw extruders, twin roll and three roll calender rolls, roll mills, plastomill, banbury mixer, kneader and planetary mixer can be used.
The kneading temperature is appropriately adjusted depending on the kind of the resin, the mixing ratio, the presence or absence of the additive, and the kind of the additive, and in order to suppress crosslinking (curing) and appropriately reduce the viscosity of the resin to facilitate kneading, it is preferably 20 ℃ or higher and 150 ℃ or lower, more preferably 30 ℃ or higher and 140 ℃ or lower, still more preferably 40 ℃ or higher and 130 ℃ or lower, particularly preferably 50 ℃ or higher and 120 ℃ or lower, and particularly preferably 60 ℃ or higher and 110 ℃ or lower.
The kneading time is not particularly limited as long as the materials constituting the resin composition are uniformly mixed, and is, for example, several minutes to several hours, preferably 5 minutes to 1 hour.
The present film (1) can be partially cured by heating, irradiating, imparting moisture to, or combining the films obtained as described above. In the present invention, it is preferable to use radiation from the viewpoint of being able to easily adjust the properties of the film and being able to mass-produce at a high speed.
That is, the method for producing the thin film (1) preferably includes a step of irradiating with radiation. In addition, the method of forming the release film preferably includes the steps of: after irradiation of the resin layer laminated on the release film with radiation, the release film is peeled from the resin layer.
< molded article >
The film (1) can be molded into a molded article by molding with a mold such as a metal mold and curing, and typically can be molded into various molded articles by molding with a mold. The curing may be performed according to the characteristics of the present film (1), and may be performed by heating, light irradiation, moisture imparting, or a combination thereof, but is preferably performed by heating. The present film (1) is useful as a film for a diaphragm, and a molded article formed from the present film (1) is particularly useful as an acoustic member such as a diaphragm.
In the present invention, the gel fraction of the molded article obtained from the film may be 80% or more. When the gel fraction is 80% or more, a molded article having a storage modulus and mechanical strength suitable for an acoustic member can be easily obtained. The gel fraction of the molded article is more preferably 85% or more, particularly preferably 90% or more. The gel fraction of the molded article is not particularly limited as long as it is 100% or less, usually less than 100%, and for example, 99% or less. The gel fraction of the molded article refers to the gel fraction of the entire molded article, and can be measured by sampling uniformly in the thickness direction of the molded article. Details of the method for measuring the gel fraction are described in examples.
Method for producing molded article
The molded article can be obtained by using the present film (1). Hereinafter, a method for producing a molded article using the present film (1) will be described.
When a molded article is obtained from the present film (1), it is preferable to perform at least the following steps 1 and 2.
Step 1: a step of heating the film (1), molding the film by a mold, and curing the film (1)
Step 2: a step of releasing the formed and cured film (1) (i.e., a formed article) from the mold
Hereinafter, each step will be described in more detail.
(Process 1)
In step 1, the present film (1) is heated and molded by a mold, and the present film (1) is cured to form a molded article. The molded article may be molded by a mold, thereby being molded into a desired shape. The molding in step 1 is not particularly limited, and may be performed by any molding method such as vacuum molding, pressure forming, and press forming, and among these, press forming is preferable in terms of easier molding.
As the mold, a mold corresponding to the molding method may be prepared, and the mold may be provided with irregularities corresponding to the shape of the molded article to be produced. As the mold, a metal mold (metal mold) is typically used, but a resin mold may be used. For example, as described later, if the molded article (vibration plate) has at least one of a dome shape and a cone shape, the mold may be provided with irregularities corresponding to the dome shape or the cone shape. In addition, when the molded article (vibration plate) has a tangential edge on the surface, the mold may be provided with irregularities corresponding to the tangential edge.
The film (1) may be provided with a release film as described above, and the film (1) may be set in a mold after the release film is peeled off as described above.
In the step 1, the heated film (1) may be shaped by a mold, for example, the film (1) placed on the mold may be shaped by the mold while being heated, the preheated film (1) may be placed on the mold, and then the film (1) may be shaped by the mold, or the film and the film may be combined. In addition, the film (1) may be heated by any method, for example, in the case of heating a film disposed on a mold, the mold may be heated and heated by heat transfer, or the film may be heated by another method.
The heating temperature at the time of shaping or curing is preferably 180℃to 260℃inclusive, more preferably 190℃to 250℃inclusive, still more preferably 200℃to 240℃inclusive. If the temperature at the time of shaping or curing is within this range, the film (1) tends to be cured at a sufficient rate within a range where it is not deformed by heat.
The shaping time is preferably 1 second or more and 5 minutes or less, more preferably 5 seconds or more and 4 minutes or less, still more preferably 10 seconds or more and 3 minutes or less, and particularly preferably 20 seconds or more and 2 minutes or less. If the heat treatment time at the time of shaping is within this range, the curing tends to be easy and sufficient in a state where productivity is maintained.
The present film (1) is preferably cured while being shaped, but is not particularly limited, and may be cured after shaping. The shaping time is the time for shaping and/or curing the film (1) in the mold, and does not include the time for moving the mold before the shaping is started and after the shaping is completed and the time for releasing the laminate.
(Process 2)
In step 2, the film (1) formed and cured in step 1 is peeled off from the die to obtain a formed product. In the present invention, since the gel fraction of the film (1) is smaller than a certain value, the film has high formability and high follow-up property of the film to a mold. Therefore, the molded article can be manufactured with high molding accuracy.
Further, the present film (1) has a specific viscoelastic property, and therefore has high shape retention and good handleability. Further, the release film can be peeled off without being broken when peeled off from the release film, and can be easily set in a mold while maintaining the shape of the film. Further, since the release film is not laminated, the step of peeling the release film from the molded article can be omitted, and mass production becomes easy.
< use >
The film of the present invention can be suitably used for an acoustic member. Specifically, the film can be suitably used as a film for an acoustic member, and is particularly suitably used as a film for a diaphragm. The acoustic member of the present invention, for example, the diaphragm is preferably a member obtained by curing the present film (1), and specifically, may be formed of the above-described molded product. The acoustic member is more preferably a diaphragm, specifically a speaker diaphragm, and is particularly preferably used as a micro speaker diaphragm for a mobile phone or the like.
Acoustic member-
The film (1) can be formed into various acoustic members such as a diaphragm by appropriately shaping and curing.
The acoustic member may, for example, have at least a portion thereof have a dome shape, a cone shape, or the like. In addition, the acoustic member may have tangential edges at its surface. In the case of having a dome shape or a cone shape, or having a tangential edge, the acoustic member is preferably used for a diaphragm, more preferably for a speaker diaphragm.
An acoustic member having the characteristics of the present film is a preferable mode. That is, the acoustic member formed using the present film can have a static friction coefficient of 3 or less on one surface, particularly on the surface in contact with the mold, and can be easily peeled from the mold. Suitable ranges for the coefficient of static friction are described above.
In addition, the acoustic member formed of the present film as a single-layer film has an advantage of no problem of interlayer peeling.
Further, the acoustic member formed of the present film as the silicone film is excellent in heat resistance, mechanical strength, and the like, and is easy to satisfy the viscoelastic properties (a) and (b) to (d) suitable for the acoustic member, and the tensile elongation at break is also easy to adjust within the above desired range. Specifically, (b) determination of storage modulus E' at 20 ℃. 20 Is from 0.1MPa to 500MPa, (c) the storage modulus E 'at 100 ℃ is measured' 100 0.1MPa to 500MPa, (d) the storage modulus E' 100 Relative to the storage modulus E' 20 Ratio (E ')' 100 /E’ 20 ) Is 0.2 to 1.0.
In addition, the thickness of the acoustic member can be set to 5 μm or more and 500 μm or less, and excellent acoustic characteristics can be obtained as an acoustic member such as a diaphragm. Further, by providing the acoustic member with a crosslinked structure, the viscoelastic properties (b) to (d) can be easily satisfied.
< vibrating plate >
The shape of the diaphragm is not particularly limited, and circular, elliptical, oval, or the like may be selected. In addition, the vibration plate generally has a main body that vibrates according to an electric signal or the like and an edge surrounding the periphery of the main body. The body of the diaphragm is typically edge supported. The shape of the diaphragm may be dome-shaped or cone-shaped as described above, or may be a combination of these, or may be another shape used in the diaphragm.
The present film (1) may be formed as at least a part of the acoustic member, and for example, the main body or edge of the vibration plate may be formed of the present film (1) and the edge or main body of the vibration plate may be formed of another member. Of course, both the main body and the edge may be integrally formed by the present film (1), or the entire diaphragm may be formed by the present film (1).
Fig. 1 is a diagram showing a structure of a vibration plate 1 according to an embodiment of the present invention, and is a cross-sectional view of a vibration plate 1 having a circular shape in a plan view, which is obtained by cutting a surface passing through a center line of a circle. The diaphragm 1 is a diaphragm for a micro-speaker. As shown in fig. 1, the diaphragm 1 includes a recessed portion 1b attached to the voice coil 2 around a dome portion (main body) 1a, a peripheral portion (edge) 1c, and an external adhesive portion 1d attached to a frame or the like on the outer periphery thereof.
Fig. 2 is a view showing a structure of a vibration plate 11 according to another embodiment of the present invention, and is a cross-sectional view of a vibration plate 11 having a circular shape in a plan view, which is cut on a plane passing through a center line of the circle. The diaphragm 11 is a diaphragm for a micro-speaker. As shown in fig. 2, the diaphragm 11 includes a concave portion 11b attached to the voice coil 2 around a dome portion (main body) 11a formed in a dome shape, a conical portion 11j formed in a conical shape, and a peripheral portion (edge) 11c. As exemplified by the vibration plate 11, the vibration plate may be a part of which is processed into a dome shape, and another part other than the part is processed into a cone shape. The peripheral edge 11c of each diaphragm 11 may be directly attached to the frame or the like, or may be attached to the frame or the like via another member.
As described above, a tangential edge may be given to the surface of the vibration plate. The tangential edge may for example be constituted by a groove or the like having a V-shaped cross-section. Fig. 3 shows a top view of a vibration plate 21 according to still another embodiment of the present invention. The diaphragm 21 has, at an outer peripheral edge portion of a circular dome portion (main body) 21 a: a plurality of tangential edge portions 21g to which tangential edges 21e are provided, and a plurality of tangential edge portions 21h to which tangential edges 21f are provided, which are arranged on the outer periphery of the tangential edge portions 21 g. In fig. 3, an example in which 2 tangential edge portions are provided in the radial direction is shown, but the number of tangential edge portions may be 1 or 3 or more in the radial direction.
As described above, the diaphragm is preferably a speaker diaphragm, and among them, a micro speaker diaphragm is preferable. From the viewpoint of being suitable for use as a micro-speaker diaphragm, a diaphragm having a maximum diameter of 25mm or less, preferably 20mm or less, and a maximum diameter of 5mm or more is suitably used as the size of the diaphragm. The maximum diameter is a diameter when the shape of the diaphragm is a circular shape, and is a long diameter when the shape of the diaphragm is an elliptical shape or an oval shape.
The diaphragm may be formed of the present film (1) alone or may be formed of a composite material of the present film (1) and other members. For example, either the edge or the body may be formed of other members as described above.
Further, in order to adjust the secondary working adaptability, dust resistance, acoustic characteristics, and the like of the vibration plate, and to improve the appearance, the surface of the vibration plate may be appropriately subjected to a treatment such as further coating with an antistatic agent, vapor deposition of a metal, sputtering, or coloring (black, white, or the like). Further, lamination with a metal such as aluminum, lamination with a nonwoven fabric, or the like may be suitably performed.
(Acoustic transducer)
The acoustic transducer of the present invention is an acoustic transducer including the acoustic member, preferably a diaphragm. As the acoustic transducer, typically an electroacoustic transducer, a speaker, a receiver, a microphone, an earphone, and the like are exemplified. Among these, the acoustic transducer is preferably a speaker, and is preferably a micro speaker of a mobile phone or the like.
[ mode for the invention ] 2
In embodiment 2 of the present invention, a single-layer silicone film having curability and a static friction coefficient of at least one surface of 3 or less is provided.
< Silicone film >
The single-layer silicone film of the present invention (hereinafter, sometimes referred to as "the present film (2)") is characterized by having curability and a static friction coefficient of at least one surface of 3 or less.
That is, the present film (2) has curability and at least a part of uncured portion, and therefore has formability, and the static friction coefficient is 3 or less, so that the peeling from the mold or the release film becomes good. Further, since the film is a single layer, there is no problem of delamination.
The method for producing the silicone thin film of the present invention, that is, the thin film having a film shape, curability, and a static friction coefficient of at least one surface of 3 or less, preferably involves irradiation with radiation to form a so-called semi-crosslinked structure.
Radiation ray
The radiation used for producing the thin film of the present invention is not particularly limited as long as it exhibits the effects of the present invention, and examples thereof include X-rays, γ -rays, electron rays, β -rays, α -rays, protons, deuterons, heavy ions, neutron rays, and mesogenic rays.
The radiation dose and the radiation irradiation time are desirably adjusted so as to conform to the ranges of the gel fraction and/or storage modulus described below, depending on the type of radiation.
< gel fraction >
The gel fraction of the film (2) is preferably 60% to 90%. When the gel fraction is within this range, the effect of the present invention is exhibited by the surface layer portion being moderately cured and the inside being uncured or semi-cured. From the above viewpoints, the gel fraction of the present film (2) is more preferably 60% or more and 85% or less, and still more preferably 65% or more and 80% or less.
The gel fraction was measured by the method described in examples.
The silicone polymer (organopolysiloxane) used in the present film (2) has a structure represented by the following formula (I), for example.
R n SiO (4-n)/2 ···(I)
Here, R may be the same or different and is a substituted or unsubstituted monovalent hydrocarbon group, preferably a monovalent hydrocarbon group having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, and n is a positive number of 1.95 to 2.05.
R may be, for example, as follows: alkyl groups such as methyl, ethyl, propyl, butyl, hexyl, and dodecyl; cycloalkyl groups such as cyclohexyl; alkenyl groups such as vinyl, allyl, butenyl, and hexenyl; and chloromethyl, trifluoropropyl, cyanoethyl, and the like, in which part or all of the hydrogen atoms bonded to carbon atoms of these groups are substituted with halogen atoms, cyano groups, and the like.
The organopolysiloxane of the present invention is preferably terminated at the molecular chain end with trimethylsilyl group, dimethylvinyl group, dimethylhydroxysilyl group, trivinylsilyl group, or the like. Furthermore, the organopolysiloxane preferably has at least 2 alkenyl groups in the molecule. Specifically, R preferably has an alkenyl group of 0.001 mol% or more and 5 mol% or less, preferably 0.005 mol% or more and 3 mol% or less, more preferably 0.01 mol% or more and 1 mol% or less, particularly preferably 0.02 mol% or more and 0.5 mol% or less, and particularly preferably has a vinyl group. The organopolysiloxane is substantially linear, but may also be partially branched. In addition, the compound may be a mixture of 2 or more kinds of compounds having different molecular structures.
< coefficient of static friction >
The film (2) is characterized in that the static friction coefficient of at least one surface is 3 or less. By setting the static friction coefficient to 3 or less, the film handling properties are improved, for example, in the case of a release film with a release film, peeling from the release film is facilitated, and breakage during peeling is not a concern. In addition, the film is easily peeled from the mold, and the film can be prevented from adhering to the mold during molding. From the above viewpoints, the static friction coefficient is preferably 2.8 or less, more preferably 2.5 or less, further preferably 2.3 or less, and particularly preferably 2.1 or less. The lower limit of the static friction coefficient is not particularly limited, and may be, for example, 0.3 or more, 0.5 or more, or 0.7 or more.
The coefficient of static friction is required to be 3 or less on at least one surface of the present film (2), but the coefficient of static friction on the other surface may be more than 3 or equal to 3.
The static friction coefficient is a value measured on a stainless steel plate (SUS 430), and is a value obtained by the method described in examples.
The static friction coefficient can be suitably adjusted by a film forming method, a film material, a surface portion gel fraction, and the like.
Specifically, by appropriately adjusting the surface shape, the coefficient of static friction can be adjusted, and for example, by imparting roughness to the surface portion, the coefficient of static friction can be reduced. Examples of the method for adjusting the static friction coefficient include a method for imparting irregularities by various methods such as sand blasting, shot blasting, etching, engraving, embossing roll transfer, embossing belt transfer, embossing film transfer, and surface crystallization. The surface shape can also be changed by adding particles to the film, thereby adjusting the static friction coefficient.
As a specific embodiment, a film having a static friction coefficient of 3 or less can be produced by laminating or extruding a resin composition for forming the present film (2) onto a release film having irregularities on the surface thereof and forming the film into a film shape, and irradiating the film with radiation from the release film side to crosslink the surface layer portion as described above, and transferring the irregularities of the release film.
< viscoelastic Properties (storage modulus) >)
The present film (2) preferably has the following viscoelastic properties (a).
(a) The storage modulus E' at a measurement temperature of 20 ℃ and a frequency of 10Hz is not less than 0.1MPa and not more than 500 MPa.
When the storage modulus E' is 0.1MPa or more, the film (2) is of a type laminated on a release film, and the film (2) has a suitable hardness, so that the film is easily peeled from the release film, and there is no fear of breakage during peeling. In addition, the shape can be maintained even after the release film is peeled off. On the other hand, when the storage modulus E' is 500MPa or less, the film has appropriate flexibility, and the film has excellent follow-up property to a mold and shape-forming property during molding.
From the above viewpoints, E' is preferably 0.5MPa or more and 300MPa or less, more preferably 0.8MPa or more and 200MPa or less, still more preferably 1.0MPa or more and 100MPa or less, still more preferably 1.2MPa or more and 10MPa or less, and particularly preferably 1.5MPa or more and 5MPa or less.
The present film (2) preferably has the following viscoelastic properties (b) to (d) in a cured state.
(b) Determination of storage modulus E 'at 20℃and frequency 10 Hz' 20 Is 0.1MPa to 500 MPa.
(c) Determination of storage modulus E 'at a temperature of 100℃and a frequency of 10 Hz' 100 Is 0.1MPa to 500 MPa.
(d) E 'above' 100 /E’ 20 Is 0.2 to 1.0.
(b) Determination of storage modulus E 'at 20℃and frequency 10 Hz' 20 When the pressure is 0.1MPa or more, the cured product has a certain hardness, and thus the handleability after curing is improved. On the other hand, if E' 20 When the pressure is 500MPa or less, the film (2) tends to have excellent acoustic properties such as sound quality and reproducibility of the diaphragm when used as the diaphragm. From the viewpoints of acoustic characteristics and handleability after curing, storage modulus E 'at 20℃after curing' 20 More preferably 1MPa to 400MPa, still more preferably 2MPa to 200MPa, still more preferably 3MPa to 50MPa, particularly preferably 4MPa to 10 MPa.
In addition, (c) the storage modulus E 'at a temperature of 100℃and a frequency of 10Hz was measured' 100 When the pressure is 0.1MPa or more and 500MPa or less, heat resistance is excellent, and excellent acoustic characteristics can be expected even in a high-temperature environment. From the standpoint of acoustic characteristics and handleability after curing, storage modulus E' 100 More preferably 1MPa to 400MPa, still more preferably 2MPa to 200MPa, still more preferably 3MPa to 50MPa, particularly preferably 3.5MPa to 10 MPa.
In addition, by making the ratio of storage modulus (d) (E' 100 /E’ 20 ) When the elastic modulus is in the range of 0.2 to 1.0, the change in elastic modulus due to the temperature change tends to be small, and the heat resistance tends to be good. Further, since the change in elastic modulus upon heating is small, the sound quality in a high-temperature environment is not easily lowered, and the reproducibility of sound from a low-temperature region to a high-temperature region is easily maintained to be excellent.
From the above point of view, the above ratio (E' 100 /E’ 20 ) More preferably from 0.25 to 0.99, still more preferably from 0.3 to 0.97, still more preferably from 0.25 to 0.99More preferably from 0.35 to 0.95.
The storage modulus was obtained by curing the material by a simple method of press molding with 2 flat plates under a pressure of 0.2MPa while heating at 200 ℃ for 2 minutes, and by the method described in the examples.
The film (2) is a curable film, and as the type of curing, any of photocurability, moisture curability, thermosetting and the like can be used, but thermosetting is preferable. The film (2) has thermosetting properties, and can be cured when shaping is performed while heating, so that the shaping property is better. Since the film (2) has curability, the gel fraction increases by a curing treatment such as heating.
The present film (2) preferably has a crosslinked structure. By having a moderately crosslinked structure, a film having suitable viscoelastic properties upon crosslinking curing can be easily obtained. In addition, the shape retention before curing (i.e., before molding) is easily improved.
As described above, the present film (2) may be in a state in which the surface portion is crosslinked and the inside is not cured, but in view of flexibility of the film, follow-up property to a mold at the time of molding, and formability, it is preferable that the film as a whole has a proper degree of crosslinking. That is, the film as a whole is preferably a film which is harder than the uncrosslinked film and softer than the fully cured film.
In the present invention, the presence or absence of a crosslinked structure can be identified by the presence of an unreacted crosslinking agent and a post-reaction (decomposed) crosslinking agent contained in a trace amount in the film in the case of a condensed type, and by the presence of a vinyl group participating in a crosslinking reaction in the case of an addition type.
The thickness of the film (2) is not particularly limited, but is preferably 5 μm or more and 500 μm or less, more preferably 15 μm or more and 400 μm or less, and still more preferably 30 μm or more and 300 μm or less. If the thickness of the film is within this range, a film having a small thickness variation in the film manufacturing process can be manufactured, and for example, a molded article having a thickness suitable for a diaphragm can be manufactured.
< elongation at break in tension >
In the cured state, the tensile elongation at break of the film (2) is preferably 100% or more, more preferably 200% or more, and still more preferably 300% or more. If the tensile elongation at break is within this range, the toughness of the film becomes high, and breakage due to vibration over a long period of time is less likely to occur, and durability when used in an acoustic member such as a diaphragm tends to be excellent. The higher the tensile elongation at break, the better, and the upper limit is not particularly limited, but is usually 1500% or less.
The tensile elongation at break was measured by the method according to JIS K7161: 2014, and measuring elongation at break of the cured film (2) at a stretching speed of 200 mm/min at 23 ℃ in TD (direction perpendicular to the flow direction of the resin).
In the resin composition for forming the present film (2), a crosslinking agent may be compounded in addition to the above-mentioned organopolysiloxane, and among them, an organic peroxide is preferably compounded. By compounding an organic peroxide, the present film (2) can be easily cured in the subsequent molding and the like.
In view of flexibility of the film, follow-up property to a mold at the time of molding, and shaping property, a film having a proper degree of crosslinking is preferable. That is, as the hardness, a film that is harder than the uncrosslinked film and softer than the fully cured film is preferable. For example, the gel fraction may be semi-cured so as to fall within a desired range.
Examples of the organic peroxide include: organic peroxides such as dialkyl peroxides, e.g., di-t-butyl peroxide, 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexane, and 2, 5-dimethyl-2, 5-bis (t-butylperoxy) hexane, and aralkyl peroxides, e.g., 2, 4-dicumyl peroxide, are preferable from the viewpoints of crosslinking rate and safety, and 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexane is particularly preferable.
The blending amount of the organic peroxide in the resin composition for forming the thin film (2) is preferably 0.01 mass% or more and 10 mass% or less, more preferably 0.03 mass% or more and 5 mass% or less, still more preferably 0.05 mass% or more and 4 mass% or less, particularly preferably 0.1 mass% or more and 3 mass% or less, and particularly preferably 0.3 mass% or more and 2 mass% or less, based on the total amount of the resin composition. When the blending amount of the organic peroxide is within this range, a composition having a sufficient curing speed tends to be obtained safely.
The resin composition for forming the present film (2) is preferably a kneading type containing an organopolysiloxane. The kneaded resin composition is in a non-liquid state (e.g., solid or paste) without flowing at room temperature (25 ℃) in an uncured state (e.g., uncured state before irradiation with radiation), but can be uniformly mixed by a kneader described later.
The resin composition for forming the present film (2) may be mixed with a resin other than a silicone resin (organopolysiloxane) as a resin.
The film (2) may contain a filler. The filler may be suitably a silica such as cerium oxide (cerium oxide), fumed silica or precipitated silica. The film (2) can easily bring the mechanical properties such as storage modulus and tensile elongation at break of the film into proper ranges by containing the filler. In addition, by using the filler, the viscosity and hardness of the resin composition can be easily adjusted, and the balance between the fluidity and secondary processability of the resin composition can be easily optimized. Further, there is an advantage that the hardness can be easily adjusted appropriately according to the design and acoustic characteristics of the acoustic member.
The filler constitutes a part of the gel component in the measurement of the gel fraction, and the gel fraction of the film (2) is increased by containing the filler. The hardness of the film (2) can be improved by containing the filler to increase the gel fraction as in the case of crosslinking to increase the gel fraction.
The content of the filler in the resin composition for forming the present film (2) is, for example, 10 mass% or more and 50 mass% or less, preferably 15 mass% or more and 40 mass% or less, more preferably 20 mass% or more and 35 mass% or less, based on the total amount of the resin composition. The average particle diameter of the filler is, for example, 0.01 μm or more and 20 μm or less, preferably 0.1 μm or more and 10 μm or less, and more preferably 0.5 μm or more and 5 μm or less. The average particle diameter of the filler can be measured as the median particle diameter (D50) using a particle size distribution measuring apparatus based on a laser diffraction method or the like.
The resin composition for forming the present film (2) may contain various additives such as heat stabilizer, antioxidant, ultraviolet absorber, light stabilizer, antibacterial/antifungal agent, antistatic agent, lubricant, pigment, dye, flame retardant, impact resistance improver and the like within a range not impairing the effect.
In the present invention, commercially available organopolysiloxanes can be used. In addition, a commercially available product containing a mixture of additives such as a cerium oxide filler and a silica filler in addition to the organopolysiloxane can also be used. Specifically, trade names "KE-5550-U", "KE-597-U", "KE-594-U", etc. manufactured by Xinyue chemical industries, inc. may also be used.
< Silicone film with Release film >
The film (2) is provided with a release film and can be used as an organosilicon film with a release film. The silicone film with a release film comprises: the present film (2) and a release film provided on at least one side of the present film (2).
In addition, in the silicone film with a release film, the release film is preferably provided on both sides of the present film (2).
The release film may be a resin film or a film having a release layer formed by a release treatment on at least one side of a resin film. When the release film has a release layer, the release layer may be laminated on the film (2) so as to be in contact with the film (2).
As the resin for the release film, there can be exemplified: polyolefin resins such as polypropylene, acrylic resins, polystyrene resins, polyacetal resins, polyamide resins, polyester resins, polycarbonate resins, ABS resins, polyether ether ketone resins, and the like. Among these, polyester-based resins are preferable, and among them, polyethylene terephthalate-based resins are preferable.
The thickness of the release film is not particularly limited, but is preferably 5 μm or more and 150 μm or less, more preferably 7 μm or more and 120 μm or less, still more preferably 10 μm or more and 100 μm or less, and particularly preferably 10 μm or more and 80 μm or less.
The film (2) is protected by the release film. Therefore, damage to the film (2) during transportation or the like is prevented. The release film may be used as it is when the present film (2) is produced, or may be laminated separately to the present film (2) after production.
The present film (2) is molded by, for example, shaping as described later, but the mold release film may be peeled off from the present film (2) at the time of molding and then placed in a mold such as a metal mold. In this case, the present film (2) can be peeled off from the release film without being damaged.
< method for producing the film (2)
The film (2) can be molded by a usual molding method, for example, extrusion molding or the like. The resin composition for obtaining a film may be obtained by kneading or the like as described below, and may be molded by extrusion molding or the like. In order to adjust the static friction coefficient to 3 or less, the film may be subjected to post-processing such as embossing as described above.
The present film (2) with a release film having a static friction coefficient of 3 or less may be obtained by laminating a resin composition between release films or on a release film by lamination molding using a release film having irregularities.
More specifically, the following methods are suitably used.
A method for producing the present film (1) (film for acoustic member) comprises the steps of: laminating a resin layer between 2 release films having a surface roughness (Ra) of 0.10 to 6.00 [ mu ] m; a step of curing the laminated resin layers; and a step of peeling at least 1 release film from the cured resin layer.
Here, the surface roughness (Ra) was measured by the method described in examples.
The resin compositions are not particularly limited, and may be obtained by kneading materials constituting the resin compositions, for example. As the kneading machine used for kneading, known kneading machines such as extruders such as single screw and twin screw extruders, twin roll and three roll calender rolls, roll mills, plastomill, banbury mixer, kneader and planetary mixer can be used.
The kneading temperature is appropriately adjusted depending on the kind of the resin, the mixing ratio, the presence or absence of the additive, and the kind of the additive, and in order to suppress crosslinking (curing) and appropriately reduce the viscosity of the resin to facilitate kneading, it is preferably 20 ℃ or higher and 150 ℃ or lower, more preferably 30 ℃ or higher and 140 ℃ or lower, still more preferably 40 ℃ or higher and 130 ℃ or lower, particularly preferably 50 ℃ or higher and 120 ℃ or lower, and particularly preferably 60 ℃ or higher and 110 ℃ or lower.
The kneading time is not particularly limited as long as the materials constituting the resin composition are uniformly mixed, and is, for example, several minutes to several hours, preferably 5 minutes to 1 hour.
The present film (2) can be partially cured by heating, irradiating, imparting moisture to, or combining the films obtained as described above. In the present invention, it is preferable to use radiation from the viewpoint of being able to easily adjust the properties of the film and being able to mass-produce at a high speed.
That is, the method for producing the thin film (2) preferably includes a step of irradiating with radiation. In addition, the method of forming the release film preferably includes the steps of: after the radiation is irradiated to the silicone resin layer laminated on the release film, the release film is peeled from the silicone resin layer.
[ molded article ]
The film (2) can be molded into a molded article by molding and curing with a mold such as a die, and typically can be molded into various molded articles by molding with a mold. The curing may be performed according to the characteristics of the present film (2), and may be performed by heating, light irradiation, moisture imparting, or a combination thereof, but is preferably performed by heating. The present film (2) is useful as a film for a diaphragm, and a molded article formed from the present film (2) is particularly useful as an acoustic member such as a diaphragm.
In the present invention, the gel fraction of the molded article obtained from the film may be 80% or more. When the gel fraction is 80% or more, a molded article having a storage modulus and mechanical strength suitable for an acoustic member can be easily obtained. The gel fraction of the molded article is more preferably 85% or more, particularly preferably 90% or more. The gel fraction of the molded article is not particularly limited as long as it is 100% or less, usually less than 100%, and for example, 99% or less. The gel fraction of the molded article refers to the gel fraction of the entire molded article, and can be measured by sampling uniformly in the thickness direction of the molded article. Details of the method for measuring the gel fraction are described in examples.
< method for producing molded article >
The molded article can be obtained by using the present film (2). Hereinafter, a method for producing a molded article using the present film (2) will be described.
When a molded article is obtained from the present film (2), it is preferable to perform at least the following steps 1 and 2.
Step 1: heating the film (2), molding the film by a mold, and curing the film (2)
Step 2: a step of releasing the formed and cured film (2) (i.e., a formed article) from the mold
Hereinafter, each step will be described in more detail.
(Process 1)
In step 1, the present film (2) is heated and molded by a mold, and the present film (2) is cured to form a molded article. The molded article may be molded by a mold, thereby being molded into a desired shape. The molding in step 1 is not particularly limited, and may be performed by any molding method such as vacuum molding, pressure forming, and press forming, and among these, press forming is preferable in terms of easier molding.
As the mold, a mold corresponding to the molding method may be prepared, and the mold may be provided with irregularities corresponding to the shape of the molded article to be produced. As the mold, a metal mold (metal mold) is typically used, but a resin mold may be used. For example, as described later, if the molded article (vibration plate) has at least one of a dome shape and a cone shape, the mold may be provided with irregularities corresponding to the dome shape or the cone shape. In addition, when the molded article (vibration plate) has a tangential edge on the surface, the mold may be provided with irregularities corresponding to the tangential edge.
The film (2) may be provided with a release film as described above, and the film (2) may be set in a mold after the release film is peeled off as described above.
In step 1, the heated film (2) may be shaped by a mold, for example, the film (2) placed on the mold may be shaped by the mold while being heated, the preheated film (2) may be placed on the mold, and then the film (2) may be shaped by the mold, or the film and the film may be combined. In addition, the film (2) may be heated by any method, for example, in the case of heating a film disposed on a mold, the mold may be heated and heated by heat transfer, or the film may be heated by another method.
The heating temperature at the time of shaping or curing is preferably 180℃to 260℃inclusive, more preferably 190℃to 250℃inclusive, still more preferably 200℃to 240℃inclusive. If the temperature at the time of shaping or curing is within this range, the film (2) tends to be cured at a sufficient rate within a range where it is not deformed by melting with heat.
The shaping time is preferably 1 second or more and 5 minutes or less, more preferably 5 seconds or more and 4 minutes or less, still more preferably 10 seconds or more and 3 minutes or less, and particularly preferably 20 seconds or more and 2 minutes or less. If the heat treatment time at the time of shaping is within this range, the curing tends to be easy and sufficient in a state where productivity is maintained.
The film (2) is preferably cured while being shaped, but is not particularly limited, and may be cured after being shaped. The shaping time is the time for shaping and/or curing the film (2) in the mold, and does not include the time for moving the mold before the shaping is started and after the shaping is completed and the time for releasing the laminate.
(Process 2)
In step 2, the film (2) formed and cured in step 1 is peeled off from the die to obtain a formed product. In the present invention, since the gel fraction of the film (2) is smaller than a certain value, the film has high formability and high follow-up property of the film to a mold. Therefore, the molded article can be manufactured with high molding accuracy.
Further, the present film (2) has a specific viscoelastic property, and thus has high shape retention and good handleability. Further, the release film can be peeled off without being broken when peeled off from the release film, and can be easily set in a mold while maintaining the shape of the film. Further, since the release film is not laminated, the step of peeling the release film from the molded article can be omitted, and mass production becomes easy.
[ use ]
The silicone film of the present invention can be suitably used for an acoustic member. Specifically, the film can be suitably used as a film for an acoustic member, and is particularly suitably used as a film for a diaphragm. The acoustic member of the present invention, for example, the diaphragm is preferably a member obtained by curing the present film (2), and specifically, may be formed of the above-described molded product. The acoustic member is more preferably a diaphragm, specifically a speaker diaphragm, and is particularly preferably used as a micro speaker diaphragm for a mobile phone or the like.
The film (2) can be formed into various acoustic members such as a diaphragm by suitable molding.
The acoustic member may, for example, have at least a portion thereof have a dome shape, a cone shape, or the like. In addition, the acoustic member may have tangential edges at its surface. In the case of having a dome shape or a cone shape, or having a tangential edge, the acoustic member is preferably used for a diaphragm, more preferably for a speaker diaphragm.
(vibrating plate)
The shape of the diaphragm is not particularly limited, and circular, elliptical, oval, or the like may be selected. In addition, the vibration plate generally has a main body that vibrates according to an electric signal or the like and an edge surrounding the periphery of the main body. The body of the diaphragm is typically edge supported. The shape of the diaphragm may be dome-shaped or cone-shaped as described above, or may be a combination of these, or may be another shape used in the diaphragm.
The present film (2) may be formed as at least a part of the acoustic member, and for example, the main body or edge of the vibration plate may be formed of the present film (2) and the edge or main body of the vibration plate may be formed of another member. Of course, both the main body and the edge may be integrally formed of the film (2), or the entire diaphragm may be formed of the film (2).
Fig. 1 is a diagram showing the structure of a diaphragm 1 according to an embodiment of the present invention, which is the same as the structure described in the present film (1).
Fig. 2 is a diagram showing a structure of a diaphragm 11 according to another embodiment of the present invention, which is the same as that described in the present film (1).
Fig. 3 is a plan view of a diaphragm 21 according to still another embodiment of the present invention, and fig. 3 is the same as that described in the present film (1).
As described above, the diaphragm is preferably a speaker diaphragm, and among them, a micro speaker diaphragm is preferable. From the viewpoint of being suitable for use as a micro-speaker diaphragm, a diaphragm having a maximum diameter of 25mm or less, preferably 20mm or less, and a maximum diameter of 5mm or more is suitably used as the size of the diaphragm. The maximum diameter is a diameter when the shape of the diaphragm is a circular shape, and is a long diameter when the shape of the diaphragm is an elliptical shape or an oval shape.
The diaphragm may be formed of the present film (2) alone or may be formed of a composite material of the present film (2) and other members. For example, either the edge or the body may be formed of other members as described above.
Further, in order to adjust the secondary working adaptability, dust resistance, acoustic characteristics, and the like of the vibration plate, and to improve the appearance, the surface of the vibration plate may be appropriately subjected to a treatment such as further coating with an antistatic agent, vapor deposition of a metal, sputtering, or coloring (black, white, or the like). Further, lamination with a metal such as aluminum, lamination with a nonwoven fabric, or the like may be suitably performed.
(Acoustic transducer)
The acoustic transducer of the present invention is an acoustic transducer including the acoustic member, preferably a diaphragm. As the acoustic transducer, typically an electroacoustic transducer, a speaker, a receiver, a microphone, an earphone, and the like are exemplified. Among these, the acoustic transducer is preferably a speaker, and is preferably a micro speaker of a mobile phone or the like.
Mode for the invention 3
In accordance with claim 3, there is provided a film for an acoustic member.
< film for Acoustic Member >
The film for acoustic member of the present invention (hereinafter also referred to as the present film (3)) has the following viscoelastic properties (a).
(viscoelastic Property)
(a) The storage modulus E' at a measurement temperature of 20 ℃ and a frequency of 10Hz is not less than 0.1MPa and not more than 500 MPa.
When the storage modulus E' is 0.1MPa or more, the film has a proper hardness, and is easily peeled from the release film, and breakage is not liable to occur at the time of peeling. In addition, the shape can be maintained even after the release film is peeled off. On the other hand, when the storage modulus E' is 500MPa or less, the film has appropriate flexibility, and it is possible to follow up the mold and shape the film during molding.
From the above viewpoints, E' is preferably 0.5MPa or more and 300MPa or less, more preferably 0.8MPa or more and 200MPa or less, and still more preferably 1.0MPa or more and 100MPa or less.
The present film (3) preferably has the following viscoelastic properties (b) to (d) in a cured state.
(b) MeasuringStorage modulus E 'at a constant temperature of 20 ℃ and a frequency of 10 Hz' 20 Is 0.1MPa to 500 MPa.
(c) Determination of storage modulus E 'at a temperature of 100℃and a frequency of 10 Hz' 100 Is 0.1MPa to 500MPa
(d) E 'above' 100 /E’ 20 0.4 to 1.0.
(b) Determination of storage modulus E 'at 20℃and frequency 10 Hz' 20 When the pressure is 0.1MPa or more, the cured product has a certain hardness, and thus the handleability after curing is improved. On the other hand, if E' 20 When the pressure is 500MPa or less, acoustic characteristics such as sound quality and reproducibility of the diaphragm tend to be excellent. From the viewpoints of acoustic characteristics and handleability after curing, storage modulus E 'at 20℃after curing' 20 More preferably from 1MPa to 400MPa, still more preferably from 2MPa to 200MPa, particularly preferably from 4MPa to 50 MPa.
In addition, (c) the storage modulus E 'at a temperature of 100℃and a frequency of 10Hz was measured' 100 When the pressure is 0.1MPa or more and 500MPa or less, heat resistance is excellent, and excellent acoustic characteristics can be expected even in a high-temperature environment. From the standpoint of acoustic characteristics and handleability after curing, storage modulus E' 100 More preferably from 1MPa to 400MPa, still more preferably from 2MPa to 200MPa, particularly preferably from 4MPa to 50 MPa.
In addition, by making the ratio of storage modulus (d) (E' 100 /E’ 20 ) In the range of 0.4 to 1.0, the change in elastic modulus due to the temperature change tends to be small, and the heat resistance tends to be good. Further, since the change in elastic modulus upon heating is small, the sound quality in a high-temperature environment is not easily lowered, and the reproducibility of sound from a low-temperature region to a high-temperature region is easily maintained to be excellent.
From the above point of view, the above ratio (E' 100 /E’ 20 ) More preferably 0.5 to 0.99, still more preferably 0.55 to 0.97, still more preferably 0.6 to 0.95.
The present film (3) may be a single-layer film or a laminated film as long as it has the viscoelastic properties of the above (a) and preferably has the viscoelastic properties of the above (b) to (d) in a cured state, but in order to satisfy the requirements of the above (a), it is important that the film has a certain degree of hardness, and in the case of the laminated film, at least one of the layers has a certain degree of hardness.
In the case of a single-layer film, the film preferably has a crosslinked structure satisfying the above condition (a), and a film having a proper degree of crosslinking is preferable in view of flexibility of the film, follow-up property to a mold during molding, and formability. That is, as the hardness, a film (low-hardness film) which is harder than the uncrosslinked film and softer than the fully cured film is preferable.
In addition, in the case of a multilayer film, a part of the layer may have a crosslinked structure and may have a high hardness (hereinafter, may be referred to as a "high-cure layer"). That is, the present film (3) preferably has at least 1 highly cured layer and at least 1 uncured layer. Specifically, there may be mentioned 2-layer structures of high cured layer/uncured layer, 2-layer structures of high cured layer/uncured layer/high cured layer, uncured layer/high cured layer/uncured layer. In addition, for example, a 4-layer structure having 2 layers in the intermediate layer may be used, and an adhesive layer may be provided between the layers. In this way, in the case of a laminated film, by designing the hardness of any one layer to be high, a laminated film satisfying the above condition (a) is easily obtained, and a laminated structure having a high cured layer/uncured layer/high cured layer is particularly preferable.
Here, the uncured layer includes not only the case where it is not crosslinked at all but also a partially crosslinked manner where a part is crosslinked, and for example, the above-mentioned low-hardness film may be used as the uncured layer. And, the gel fraction of the uncured layer may be lower than that of the high cured layer.
(gel fraction)
The gel fraction of the film (3) is preferably 90% or less. When the gel fraction is 90% or less, the film before molding can be softened, sufficient curing can be obtained during molding, and formability and follow-up property to a mold can be obtained, and formability to a practical degree can be obtained.
From the viewpoint of formability and shaping property, the gel fraction is preferably 85% or less, more preferably 80% or less. The lower limit of the gel fraction is not particularly limited, and may be 0% or more, preferably 10% or more, and more preferably 20% or more. When the gel fraction is 10% or more, the above condition (a) can be easily adjusted to the above specified range, and the present film (3) is less likely to be damaged when the release film is peeled off before molding.
As mentioned above, the film preferably has at least 1 highly cured layer and at least 1 uncured layer. The uncured layer preferably has a gel fraction of 0% or more and less than 80%. If the gel fraction of the uncured layer is less than 80%, the film before molding is easily softened, and the film can be sufficiently cured at the time of molding, so that the formability and the following property to the mold are sufficient, and the formability is improved.
From the viewpoint of formability and shaping property, the gel fraction of the uncured layer is preferably 70% or less, more preferably 65% or less, and further preferably 60% or less. The gel fraction of the intermediate layer is not particularly limited, and may be 0% or more, for example, 10% or more, or 20% or more.
On the other hand, the gel fraction of the high-curing layer is preferably 80% or more. When the gel fraction of the outermost layer and the innermost layer is 80% or more, the present film (3) is easily peeled from the release film, and the risk of breakage during peeling is reduced. In addition, the present film (3) can further improve the shape retention even before the film is cured by improving the gel fraction as described above.
From the above viewpoints, the gel fraction of the high-curing layer is more preferably 85% or more, and still more preferably 90% or more. The gel fraction of the high-curing layer is not particularly limited, and may be 100% or less, usually less than 100%, for example, 99% or less.
The film (3) can prevent the film from being difficult to take out from the metal mold when the film is taken out after being pressed by clamping the film in the metal mold for pressing when the gel rate of the film surface part is 75% or more, regardless of whether the film is single-layer or laminated.
The gel fraction can be measured in the following manner.
1) About 100mg of the sample was collected from the whole film or the middle layer, the outermost layer or the innermost layer of the film, and the mass (a) of the sample was measured.
2) The collected sample was immersed in chloroform at 23℃for 24 hours.
3) The solid content in chloroform was removed, and dried under vacuum at 50℃for 7 hours.
4) The mass (b) of the dried solid content was measured.
5) The gel fraction was calculated based on the following formula (i) using the masses (a) and (b).
The gel fraction was calculated as a gel component including not only the crosslinking component contained in the film but also insoluble components other than the crosslinking component such as the filler, as a result of the above measurement method.
The intermediate layer of the film (3) before curing is calculated from the gel fraction of the entire film (3) before curing and the outermost layer and the innermost layer, and the ratio of the layer thicknesses.
The film (3) is a curable film, and as the type of curing, any of photocurability, moisture curability, thermosetting and the like can be used, and thermosetting is preferable. The film (3) has thermosetting properties, and can be cured when shaping is performed while heating, so that the shaping property is better. The film (3) has thermosetting properties, and thus the gel fraction increases by heating.
The present film (3) preferably has a crosslinked structure. By having a moderately crosslinked structure, as described above, a film satisfying the requirement of the viscoelastic property (a) can be easily obtained in a single-layer film. In addition, the shape retention before curing (i.e., before molding) is easily improved.
In addition, when the present film (3) is a laminated film, as described above, at least 1 layer of the plurality of layers has a crosslinked structure, whereby a film satisfying the requirement of the viscoelastic property (a) can be easily obtained. In the case of such a film, the shape retention before curing is easily improved without significantly impairing the flexibility of the film.
The thickness of the film (3) is not particularly limited, but is preferably 5 μm or more and 500 μm or less, more preferably 15 μm or more and 400 μm or less, and still more preferably 30 μm or more and 300 μm or less. If the thickness of the film is within this range, a molded article suitable for the thickness of the vibration plate can be produced.
(elongation at Break under tension)
In the cured state, the tensile elongation at break of the film (3) is preferably 100% or more, more preferably 200% or more, and still more preferably 300% or more. If the tensile elongation at break is within this range, the toughness of the film becomes high, and breakage due to vibration over a long period of time is less likely to occur, and durability when used in an acoustic member such as a diaphragm tends to be excellent. The higher the tensile elongation at break, the better, and the upper limit is not particularly limited, but is usually 1500% or less.
The storage modulus and the tensile elongation at break may be measured by the methods described in examples, and the storage modulus and the tensile elongation at break in the cured state may be measured on a film cured so that the gel fraction of the entire film (3) is 80% or more. Specific examples of the method for curing the film (3) so that the gel fraction is 80% or more include heat-based curing and radiation-based curing.
In the case of curing by heating, the heating temperature at the time of curing is preferably 180 ℃ or more and 260 ℃ or less, more preferably 190 ℃ or more and 250 ℃ or less, still more preferably 200 ℃ or more and 240 ℃ or less.
The heating time is preferably 1 second or more and 5 minutes or less, more preferably 5 seconds or more and 4 minutes or less, still more preferably 10 seconds or more and 3 minutes or less, and particularly preferably 20 seconds or more and 2 minutes or less.
The pressure during heating is preferably 0.01MPa to 100MPa, more preferably 0.1MPa to 50 MPa.
On the other hand, in the case of curing by radiation, as the radiation for crosslinking by radiation, electron rays, X-rays, gamma rays, or the like can be used, and the film (3) can be cured to a gel fraction of 80% or more by adjusting the kind of the radiation used and the cumulative irradiation dose.
Further, as described in the examples, the details of the method for measuring the storage modulus and the tensile elongation at break may be such that TD (direction perpendicular to the flow direction of the resin) is measured when the film has directionality.
The film (3) is composed of a resin layer, and the resin constituting the resin layer is preferably a curable resin, more preferably a thermosetting resin. Among them, preferable specific examples include epoxy resins, polyurethane resins, silicone resins, acrylic resins, phenolic resins, unsaturated polyester resins, polyimide resins, melamine resins, and the like. In the case where the film (3) is a multilayer film, it is preferable that any one of the layers is a resin layer. In the layers of the film (3), 1 kind of these resins may be used alone, or 2 or more kinds may be used in combination.
In the case where the film (3) is a multilayer film, the same type of resin may be used for each layer, or different types of resin may be used, but the same type of resin is preferably used. By using the same kind of resin, the layers can be easily bonded even without using an adhesive layer or the like.
The present film (3) is preferably a silicone film. In the case of a multilayer film, a part of the layers may be films using a silicone resin as a resin, but it is particularly preferable to use a silicone resin in all the layers. When the film (3) is a silicone film, heat resistance, mechanical strength, and the like are excellent, and the viscoelastic properties (a) and (b) to (d) are easily satisfied. In addition, the tensile elongation at break is also easily adjusted within the above-described desired range.
(organopolysiloxane)
The silicone resin used in the film (3) includes an organopolysiloxane.
The organopolysiloxane has, for example, a structure represented by the following formula (I).
R n SiO (4-n)/2 ···(I)
Here, R may be the same or different and is a substituted or unsubstituted monovalent hydrocarbon group, preferably a monovalent hydrocarbon group having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, and n is a positive number of 1.95 to 2.05.
R may be, for example, as follows: alkyl groups such as methyl, ethyl, propyl, butyl, hexyl, and dodecyl; cycloalkyl groups such as cyclohexyl; alkenyl groups such as vinyl, allyl, butenyl, and hexenyl; aryl groups such as phenyl and tolyl; aralkyl groups such as beta-phenylpropyl; and chloromethyl, trifluoropropyl, cyanoethyl, and the like, in which part or all of the hydrogen atoms bonded to carbon atoms of these groups are substituted with halogen atoms, cyano groups, and the like.
The organopolysiloxane is also preferably terminated at the molecular chain end with trimethylsilyl, dimethylvinyl, dimethylhydroxysilyl, trivinylsilyl, or the like. In addition, the organopolysiloxane preferably has at least 2 alkenyl groups in the molecule. Specifically, R preferably has an alkenyl group of 0.001 mol% or more and 5 mol% or less, preferably 0.005 mol% or more and 3 mol% or less, more preferably 0.01 mol% or more and 1 mol% or less, particularly preferably 0.02 mol% or more and 0.5 mol% or less, and particularly preferably has a vinyl group. The organopolysiloxane is a substantially linear diorganopolysiloxane, but may also be partially branched. In addition, the compound may be a mixture of 2 or more kinds of compounds having different molecular structures.
The organopolysiloxane constituting the resin layer of the present film (3) may be crosslinked by a crosslinking agent or the like, preferably by an organic peroxide. Therefore, the resin layer is preferably a cured product obtained by curing a resin composition containing a crosslinking agent such as an organopolysiloxane and an organic peroxide. In this case, the resin layer may be cured so that the gel fraction falls within the above-described desired range.
In the case of the above-mentioned single-layer film, it is preferable to have a moderately crosslinked structure and a moderately hard structure. The gel fraction may be semi-cured so as to fall within the above-described desired range. Therefore, the organic peroxide compounded in the resin layer constituting the single-layer film may be partially decomposed, and a part of the organic peroxide may be contained in the resin layer without being decomposed and in a state of being kept.
On the other hand, when the film (3) is a multilayer film, it is preferable to have at least a high-cured layer and an uncured layer. The organopolysiloxane of the high curing layer is preferably crosslinked by an organic peroxide, which is decomposed to be hardly contained. On the other hand, the uncured layer is preferably formed of a resin composition having a crosslinking agent such as an organopolysiloxane and an organic peroxide, and is in an uncured or semi-cured state even if cured so that the gel fraction falls within the above-described desired range, and the organic peroxide compounded in the uncured layer can be contained in the uncured layer in a state in which the organic peroxide is kept substantially undissolved.
In the case where the film (3) is a laminated film of 2 types of 3 layers, for example, there are a case where the top layer and the back layer are highly cured layers and the intermediate layer is an uncured layer, and a case where the top layer and the back layer are uncured layers and the intermediate layer is a highly cured layer. The organopolysiloxane in the uncured layer is in an uncrosslinked state or a partially crosslinked state (semi-cured state) even if crosslinked, and the state in which the organic peroxide remains almost undissolved while the organic peroxide is contained in the uncured layer, regardless of the layer configuration. On the other hand, the organopolysiloxane of the high curing layer is preferably crosslinked by an organic peroxide, which is decomposed to be hardly contained.
Examples of the organic peroxide include: organic peroxides such as dialkyl peroxides, e.g., di-t-butyl peroxide, 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexane, and 2, 5-dimethyl-2, 5-bis (t-butylperoxy) hexane, and aralkyl peroxides, e.g., 2, 4-dicumyl peroxide, are preferable from the viewpoints of crosslinking rate and safety, and 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexane is particularly preferable.
The amount of the organic peroxide blended in the resin composition for forming the resin layer is preferably 0.01% by mass or more and 10% by mass or less, more preferably 0.03% by mass or more and 5% by mass or less, still more preferably 0.05% by mass or more and 4% by mass or less, particularly preferably 0.1% by mass or more and 3% by mass or less, and particularly preferably 0.3% by mass or more and 2% by mass or less, based on the total amount of the resin composition. When the blending amount of the organic peroxide is within this range, a composition having a sufficient curing speed tends to be obtained safely. The organic peroxide blended in the resin composition is substantially decomposed in the high-curing layer and is hardly contained, but the organic peroxide may be contained in the uncured layer within the above-mentioned blending amount range.
The resin composition is preferably a kneading type containing an organopolysiloxane. The kneaded resin composition is not liquid (for example, solid or paste) without fluidity at room temperature (25 ℃) in an uncured state, but can be uniformly mixed by a kneader described later. In the present film (3), by using the kneaded resin composition, productivity is good when the resin composition is processed into an intermediate layer or an outermost layer and an innermost layer in the case of a laminated film.
In addition, as described above, the resin composition forming the resin layer may use a resin other than a silicone resin (organopolysiloxane), and in this case, the outermost layer and the innermost layer may be layers obtained by curing a resin composition containing a resin and a crosslinking agent so that the gel fraction falls within a desired range, for example. The intermediate layer may be formed of a resin composition containing a resin and a crosslinking agent, and in this case, the resin composition may be uncured or semi-cured even if cured so that the gel fraction falls within the above-mentioned predetermined range.
The resin layer constituting the thin film (3) may contain a filler such as a silica filler. The film (3) can easily bring the mechanical properties such as storage modulus and tensile elongation at break of the film into proper ranges by containing the filler. In addition, by using the filler, the viscosity and hardness of the resin composition can be easily adjusted, and the balance between the fluidity and secondary processability of the resin composition can be easily optimized. Further, there is an advantage that the hardness can be easily adjusted appropriately according to the design and acoustic characteristics of the acoustic member.
The filler forms a part of the gel component in the measurement of the gel fraction, and the gel fraction of each layer is increased by containing the filler. The hardness of each layer can be improved by containing the filler to increase the gel fraction as in the case of increasing the gel fraction by crosslinking.
Examples of the silica-based filler include fumed silica and precipitated silica, and may be a silica-based filler surface-treated with a silane coupling agent.
The content of the filler in each layer is, for example, 10 mass% or more and 50 mass% or less, preferably 15 mass% or more and 40 mass% or less, and more preferably 20 mass% or more and 35 mass% or less, based on the total amount of the resin composition constituting each layer. The average particle diameter of the filler is, for example, 0.01 μm or more and 20 μm or less, preferably 0.1 μm or more and 10 μm or less, and more preferably 0.5 μm or more and 5 μm or less. The average particle diameter of the filler can be measured as the median particle diameter (D50) using a particle size distribution measuring apparatus based on a laser diffraction method or the like.
In the present invention, the resin composition for forming the resin layer may contain various additives such as a heat stabilizer, an antioxidant, an ultraviolet absorber, a light stabilizer, an antibacterial/antifungal agent, an antistatic agent, a lubricant, a pigment, a dye, a flame retardant, an impact resistance improver, and the like within a range that does not impair the effect.
In the case where the film (3) is a laminated film, the resin compositions used for forming the respective layers may have the same composition or may have different compositions. The composition of the resin composition as used herein refers to the composition of the resin composition before curing.
In the present invention, commercially available organopolysiloxanes can be used. In addition, a commercially available product containing a mixture of additives such as a silica-based filler in addition to the organopolysiloxane can also be used. Specifically, trade names "KE-597-U", "KE-594-U", etc. manufactured by Xinyue chemical industries, inc. may also be used.
[ film with Release film ]
The present film (3) is provided with a release film, and can be used as a film with a release film. The film with a release film is provided with the film (3) and a release film provided on at least one side of the film (3).
In addition, in the film with a release film, the release film is preferably provided on both sides of the present film (3).
The release film may be a resin film or a film having a release layer formed by a release treatment on at least one side of the resin film. When the release film has a release layer, the release layer may be laminated on the film (3) so as to be in contact with the film (3).
As the resin used for the resin film, there may be exemplified: polyolefin resins such as polypropylene, acrylic resins, polystyrene resins, polyacetal resins, polyamide resins, polyester resins, polycarbonate resins, ABS resins, polyether ether ketone resins, and the like. Among these, polyester-based resins are preferable, and among them, polyethylene terephthalate-based resins are preferable.
The thickness of the release film is not particularly limited, but is preferably 5 μm or more and 100 μm or less, more preferably 7 μm or more and 80 μm or less, and still more preferably 10 μm or more and 50 μm or less.
The film (3) is protected by the release film. Therefore, damage to the film (3) during transportation or the like is prevented. The release film may be used as it is when the present film (3) is produced, or may be laminated separately to the present film (3) after production.
The present film (3) is molded by, for example, shaping as described later, but may be set in a mold such as a metal mold after the release film is peeled off from the present film (3) at the time of molding. At this time, the present film (3) can be peeled off from the release film without being broken.
[ method for producing the film (3) ]
The film (3) can be molded by a usual molding method, for example, extrusion molding or the like. In the case of a single-layer film, a resin composition for obtaining a single-layer film may be obtained by kneading or the like as described below, and then molded by extrusion molding or the like. Alternatively, a release film may be used, and the present film (3) with a release film may be obtained by laminating a resin composition between release films by lamination molding.
In the case of a single-layer film, it is preferable to perform half-curing so as to satisfy the condition (a) of the viscoelastic property. The conditions for the semi-curing are not particularly limited as long as the above condition (a) is satisfied.
In the case where the present film (3) is a laminated film, it can be formed by, for example, extrusion molding such as lamination molding or coextrusion molding, coating, or a combination thereof. Among these, laminate molding is preferable in view of ease of multilayering of the outermost layer and the innermost layer with the intermediate layer.
As described above, in the method for producing the present film (3), it is preferable to provide a step of curing at least a part of 1 or more resin layers constituting the film.
In the case of a multilayer, it is preferable to provide a step of laminating a cured resin layer and a resin layer having curability.
In the case of using lamination molding, the outermost layer and the innermost layer may be prepared first, and an intermediate layer may be laminated between the outermost layer and the innermost layer.
More specifically, first, a resin composition for obtaining the top layer and the bottom layer (resin composition for the top layer or bottom layer) and a resin composition for obtaining the intermediate layer (resin composition for the intermediate layer) may be prepared.
The resin compositions are not particularly limited, and may be obtained by kneading materials constituting the resin compositions, for example. As the kneading machine used for kneading, known kneading machines such as extruders such as single screw and twin screw extruders, twin roll and three roll calender rolls, roll mills, plastomill, banbury mixer, kneader and planetary mixer can be used.
The kneading temperature is appropriately adjusted depending on the kind of the resin, the mixing ratio, the presence or absence of the additive, and the kind of the additive, and in order to suppress crosslinking (curing) and appropriately reduce the viscosity of the resin to facilitate kneading, it is preferably 20 ℃ or higher and 150 ℃ or lower, more preferably 30 ℃ or higher and 140 ℃ or lower, still more preferably 40 ℃ or higher and 130 ℃ or lower, particularly preferably 50 ℃ or higher and 120 ℃ or lower, and particularly preferably 60 ℃ or higher and 110 ℃ or lower.
The kneading time is not particularly limited as long as the materials constituting the resin composition are uniformly mixed, and is, for example, several minutes to several hours, preferably 5 minutes to 1 hour.
Hereinafter, a method for producing a film of 2 layers, i.e., 3 layers, i.e., high-cure layer/uncured layer/high-cure layer, will be described.
The resin composition for the outermost layer or the innermost layer prepared as described above may be laminated on a release film by a usual method to obtain a laminate, and then the laminate may be heated to cure the resin composition. Thus, a laminate in which the outermost layer or the innermost layer is laminated on the release film is obtained.
In the case where the laminate has a release treated surface, the resin composition for the outermost layer and the innermost layer may be laminated on the release treated surface of the release film.
Next, an intermediate layer formed of the resin composition for an intermediate layer may be laminated between the laminated films by lamination molding, thereby obtaining the present film (3). Specifically, the resin composition for an intermediate layer is put between laminated films which are discharged from two directions between a pair of rolls, for example, in an uncured or semi-cured state. Here, the resin composition for the intermediate layer may be fed between the laminated films by extrusion from a T die or the like using an extruder or the like, for example. The laminated films may be discharged such that the outermost layer and the innermost layer are positioned inward and face each other.
The thickness is adjusted by the gap between the rolls as needed, and a laminate in which an intermediate layer in an uncured or semi-cured state is formed between the laminated films is obtained. The laminate may have a laminate structure of a release film/an outermost layer/an intermediate layer/an innermost layer/a laminate film, and may be the film with a release film.
On the other hand, in the case of the uncured layer/highly cured layer/uncured layer system, a single-layer film is obtained by extrusion molding or the like in advance at the beginning, and is crosslinked and cured to prepare a single-layer film for a highly cured layer. Then, the resin composition for the uncured layer is applied to both sides of the high-cure layer, whereby a film of the present embodiment can be produced.
[ molded article ]
The film (3) can be molded into a molded article by molding and curing with a mold such as a die, and typically can be molded into various molded articles by molding with a mold. The curing may be performed according to the characteristics of the present film (3), and may be performed by heating, light irradiation, moisture imparting, or a combination thereof, but is preferably performed by heating. The film (3) is a film for a diaphragm, and the molded product constitutes the diaphragm.
When a molded article is obtained from the present film (3), it is preferable to perform at least the following steps 1 and 2.
Step 1: heating the film (3) and molding the film by a mold, and curing the film (3)
Step 2: a step of releasing the formed and cured film (3) (i.e., a formed article) from the mold
Hereinafter, each step will be described in more detail.
(Process 1)
In step 1, the present film (3) is heated and molded by a mold, and the present film (3) is cured to form a molded article. The molded article may be molded by a mold, thereby being molded into a desired shape. The molding in step 1 is not particularly limited, and may be performed by any molding method such as vacuum molding, pressure forming, and press forming, and among these, press forming is preferable in terms of easier molding.
As the mold, a mold corresponding to the molding method may be prepared, and the mold may be provided with irregularities corresponding to the shape of the molded article to be produced. As the mold, a metal mold (metal mold) is typically used, but a resin mold may be used. For example, as described later, if the molded article (vibration plate) has at least one of a dome shape and a cone shape, the mold may be provided with irregularities corresponding to the dome shape or the cone shape. In addition, when the molded article (vibration plate) has a tangential edge on the surface, the mold may be provided with irregularities corresponding to the tangential edge.
The film (3) may be provided with a release film as described above, and the film (3) may be set in a mold after the release film is peeled off as described above.
In the step 1, the heated film (3) may be shaped by a mold, for example, the film (3) placed on the mold may be shaped by the mold while being heated, the preheated film (3) may be placed on the mold, and then the film (3) may be shaped by the mold, or the film and the film may be combined. In addition, the film (3) may be heated by any method, for example, in the case of heating a film disposed on a mold, the mold may be heated and heated by heat transfer, or the film may be heated by another method.
The heating temperature at the time of shaping or curing is preferably 180℃to 260℃inclusive, more preferably 190℃to 250℃inclusive, still more preferably 200℃to 240℃inclusive. If the temperature at the time of shaping or curing is within this range, the film (3) tends to be cured at a sufficient rate within a range where it is not deformed by melting with heat.
The shaping time is preferably 1 second or more and 5 minutes or less, more preferably 5 seconds or more and 4 minutes or less, still more preferably 10 seconds or more and 3 minutes or less, and particularly preferably 20 seconds or more and 2 minutes or less. If the heat treatment time at the time of shaping is within this range, the curing tends to be easy and sufficient in a state where productivity is maintained.
The film (3) is preferably cured while being shaped, but is not particularly limited, and may be cured after being shaped. The shaping time is the time for shaping and/or curing the film (3) in the mold, and does not include the time for moving the mold before the shaping is started and after the shaping is completed and the time for releasing the laminate.
(Process 2)
In step 2, the film (3) formed and cured in step 1 is peeled off from the die to obtain a formed product. In the present invention, since the gel fraction of the film (3) is smaller than a certain value, the film has high formability and high follow-up property to a mold. Therefore, the molded article can be manufactured with high molding accuracy.
Further, the present film (3) has a specific viscoelastic property, and thus has high shape retention and good handleability. Further, the release film can be peeled off without being broken when peeled off from the release film, and can be easily set in a mold while maintaining the shape of the film. Further, since the release film is not laminated, the step of peeling the release film from the molded article can be omitted, and mass production becomes easy.
In the present invention, the gel fraction of the molded article obtained from the film may be 80% or more. When the gel fraction is 80% or more, a molded article having a storage modulus and mechanical strength suitable for an acoustic member can be easily obtained. The gel fraction of the molded article is more preferably 85% or more, particularly preferably 90% or more. The gel fraction of the molded article is not particularly limited as long as it is 100% or less, usually less than 100%, and for example, 99% or less. The gel fraction of the molded article refers to the gel fraction of the entire molded article, and can be measured by sampling uniformly in the thickness direction of the molded article. Details of the method for measuring the gel fraction are as described above.
[ use of film ]
The film of the present invention can be suitably used for an acoustic member as described above. The acoustic member of the present invention is formed by curing the present film (3), and specifically, can be formed from the above-described molded article. The acoustic member is more preferably a diaphragm, specifically a speaker diaphragm, and is particularly preferably used as a micro speaker diaphragm for a mobile phone or the like.
The film (3) can be formed into various acoustic members such as a diaphragm by suitable molding.
The acoustic member may, for example, have at least a portion thereof have a dome shape, a cone shape, or the like. In addition, the acoustic member may have tangential edges at its surface. In the case of having a dome shape or a cone shape, or having a tangential edge, the acoustic member is preferably used for a diaphragm, more preferably for a speaker diaphragm.
(vibrating plate)
The shape of the diaphragm is not particularly limited, and circular, elliptical, oval, or the like may be selected. In addition, the vibration plate generally has a main body that vibrates according to an electric signal or the like and an edge surrounding the periphery of the main body. The body of the diaphragm is typically edge supported. The shape of the diaphragm may be dome-shaped or cone-shaped as described above, or may be a combination of these, or may be another shape used in the diaphragm.
The present film (3) may be formed as at least a part of the acoustic member, and for example, the main body or edge of the vibration plate may be formed of the present film (3) and the edge or main body of the vibration plate may be formed of another member. Of course, both the main body and the edge may be integrally formed of the film (3), or the entire diaphragm may be formed of the film (3).
Fig. 1 is a diagram showing the structure of a diaphragm 1 according to an embodiment of the present invention, which is the same as the structure described in the present film (1).
Fig. 2 is a diagram showing a structure of a diaphragm 11 according to another embodiment of the present invention, which is the same as that described in the present film (1).
Fig. 3 is a plan view of a diaphragm 21 according to still another embodiment of the present invention, and fig. 3 is the same as that described in the present film (1).
As described above, the diaphragm is preferably a speaker diaphragm, and among them, a micro speaker diaphragm is preferable. From the viewpoint of being suitable for use as a micro-speaker diaphragm, a diaphragm having a maximum diameter of 25mm or less, preferably 20mm or less, and a maximum diameter of 5mm or more is suitably used as the size of the diaphragm. The maximum diameter is a diameter when the shape of the diaphragm is a circular shape, and is a long diameter when the shape of the diaphragm is an elliptical shape or an oval shape.
The diaphragm may be formed of the present film (3) alone or may be formed of a composite material of the present film (3) and other members. For example, either the edge or the body may be formed of other members as described above.
Further, in order to adjust the secondary working adaptability, dust resistance, acoustic characteristics, and the like of the vibration plate, and to improve the appearance, the surface of the vibration plate may be appropriately subjected to a treatment such as further coating with an antistatic agent, vapor deposition of a metal, sputtering, or coloring (black, white, or the like). Further, lamination with a metal such as aluminum, lamination with a nonwoven fabric, or the like may be suitably performed.
(Acoustic transducer)
The acoustic transducer of the present invention is an acoustic transducer including the acoustic member, preferably a diaphragm. As the acoustic transducer, typically an electroacoustic transducer, a speaker, a receiver, a microphone, an earphone, and the like are exemplified. Among these, the acoustic transducer is preferably a speaker, and is preferably a micro speaker of a mobile phone or the like.
Mode for the invention 4
Mode 4 of the present invention is a film.
< film >
The film of the present invention (hereinafter also referred to as the present film (4)) includes: a top layer and a bottom layer (top layer and bottom layer) having a static friction coefficient of 3 or less, and at least 1 curable intermediate layer disposed between the top layer and bottom layer.
In the film (4), the outermost layer and the innermost layer are made to be relatively hard layers, so that the static friction coefficient of the outermost layer and the innermost layer is reduced, and sticking to a mold during molding can be prevented. In addition, by forming the intermediate layer having curability, the film secures a certain flexibility before molding and is sufficiently cured at the time of molding, so that the molding becomes good and the following property to the mold becomes good.
Further, the intermediate layer has curability and the film is relatively soft as a whole, but by providing relatively hard outermost layers and innermost layers on both surfaces, the soft film is properly held by the outermost layers and the innermost layers, and even if a release film or the like is not laminated on the present film (4), the shape retention before molding is good and the handleability is good. Therefore, the film (4) can be easily set in a mold to be shaped without laminating a release film, and the step of peeling the release film after shaping can be omitted.
(coefficient of static friction)
As described above, the static friction coefficients of the outermost layer and the innermost layer of the film (4) are 3 or less. If the static friction coefficient is higher than 3, the film (4) is easily stuck to a mold, and it is difficult to make the formability good. The static friction coefficient of the outermost layer and the innermost layer is preferably 2.5 or less, more preferably 2 or less, and further preferably 1.5 or less. If the static friction coefficients of the outermost layer and the innermost layer are reduced as described above, adhesion to the mold can be suppressed even further.
The static friction coefficient of the outermost layer and the innermost layer of the film (4) is not particularly limited, and may be, for example, 0.3 or more, 0.5 or more, or 0.7 or more. The coefficients of static friction of the outermost layer and the innermost layer (i.e., the outermost layer and the innermost layer) may be the same as or different from each other.
The static friction coefficient can be appropriately adjusted by the molding method of the outermost layer and the innermost layer, the materials of the outermost layer and the innermost layer, the gel fraction of the outermost layer and the innermost layer, and the like. For example, if the gel fraction of the outermost layer and the innermost layer is increased, the outermost layer and the innermost layer tend to be hard and the static friction coefficient tends to be low. More specifically, the gel fraction of the outermost layer and the innermost layer is set to 80% or more, whereby the static friction coefficient is easily set to 3 or less. In addition, the static friction coefficient can be reduced by using specific resins such as silicone resin and inorganic particles in the resins constituting the outermost layer and the innermost layer. Further, the surface shape of the outermost layer and the innermost layer can be appropriately adjusted to adjust the coefficient of static friction, and for example, the roughness can be applied to the outermost layer and the innermost layer to reduce the coefficient of static friction.
The static friction coefficient is a static friction coefficient against a stainless steel plate, and can be measured by a sliding test according to JIS K7125 (1999).
(gel fraction)
The gel fraction of the film (4) is preferably 0% or more and 90% or less. When the gel fraction is 90% or less, the film before molding is easily softened, and the film can be sufficiently cured at the time of molding, so that the formability and the follow-up property to the mold are sufficient, and the formability is improved.
The gel fraction of the present film (4) is preferably 80% or less, more preferably 75% or less, and even more preferably 70% or less from the viewpoint of formability and formability. The gel fraction of the film (4) is not particularly limited, and may be 0% or more, for example, 10% or more, or 20% or more. The gel fraction of the present film (4) is a value obtained by measuring the gel fraction of the entire film.
As described above, at least 1 curable intermediate layer is provided between the outermost layer and the innermost layer. The gel fraction of the curable intermediate layer is preferably 0% or more and less than 80%. In the case of the intermediate layer having a gel fraction of less than 80%, the film before molding is easily softened, and the film can be sufficiently cured during molding, so that the formability and the following property to the mold are sufficient, and the formability is improved.
From the viewpoint of formability and shaping property, the gel fraction of the intermediate layer is preferably 70% or less, more preferably 65% or less, and further preferably 60% or less. The gel fraction of the intermediate layer is not particularly limited, and may be 0% or more, for example, 10% or more, or 20% or more.
The curable intermediate layer may be formed of 1 layer or 2 or more layers, but is preferably formed of 1 layer. Therefore, the present film (4) preferably has a 3-layer structure of the outermost layer/intermediate layer/innermost layer, but may have a 4-layer structure or more having 2 or more intermediate layers between the outermost layer and the innermost layer, such as the outermost layer/intermediate layer/innermost layer.
The film (4) may have a layer other than the above-mentioned curable intermediate layer between the outermost layer and the innermost layer, and may have other layers such as an adhesive layer for improving the adhesion between the intermediate layer and the outermost layer and between the intermediate layer and the innermost layer. In addition, other layers such as an adhesive layer may be provided between the intermediate layers.
In the present film (4), the gel fraction of the outermost layer and the innermost layer (i.e., the outermost layer and the innermost layer) is preferably 80% or more. When the gel fraction of the outermost layer and the innermost layer is 80% or more, the static friction coefficient is easily reduced, and adhesion to a mold during molding is less likely to occur. In addition, the present film (4) can make the outermost layer and the innermost layer relatively hard even before the film is cured by increasing the gel fraction as described above, and can further improve the shape retention before molding.
From the above viewpoints, the gel fraction of the outermost layer and the innermost layer is more preferably 85% or more, and still more preferably 90% or more. The gel fraction of the outermost layer and the innermost layer is not particularly limited, and may be 100% or less, usually less than 100%, for example, 99% or less.
The gel fractions of the outermost layer and the innermost layer (i.e., the outermost layer and the innermost layer) may be the same as or different from each other.
The gel fraction can be measured in the following manner.
1) The sample mass (a) was measured by taking about 100mg of the sample from the whole film or the outermost layer or innermost layer of the film.
2) The collected sample was immersed in chloroform at 23℃for 24 hours.
3) The solid content in chloroform was removed, and dried under vacuum at 50℃for 7 hours.
4) The mass (b) of the dried solid content was measured.
5) The gel fraction was calculated based on the following formula (i) using the masses (a) and (b).
The gel fraction was calculated as a gel component including not only the crosslinking component contained in the film but also insoluble components other than the crosslinking component such as the filler, as a result of the above measurement method.
The intermediate layer of the film (4) before curing is calculated from the gel fraction of the entire film (4) before curing and the outermost layer and the innermost layer, and the ratio of the layer thicknesses.
(viscoelastic Property)
The present film (4) preferably has the following viscoelastic properties (a).
(a) The storage modulus E' at the measurement temperature of 20 ℃ is not less than 0.1MPa and not more than 500 MPa.
When the storage modulus E' is 0.1MPa or more, the entire film (4) has a certain hardness, and is easily peeled from the release film, and the possibility of occurrence of cracking during peeling is reduced. In addition, even without a release film, shape retention is easily improved. On the other hand, the film (4) can ensure a certain flexibility by setting the storage modulus E' to 500MPa or less, and can be excellent in mold follow-up property and shaping property during shaping. From these viewpoints, the storage modulus E' of the present film (4) is more preferably 0.5MPa or more, still more preferably 0.8MPa or more, still more preferably 1.0MPa or more. Further, it is more preferably 300MPa or less, still more preferably 200MPa or less, still more preferably 100MPa or less, and particularly preferably 50MPa or less.
The present film (4) preferably has the following viscoelastic properties (b) in a cured state, and also preferably has the following viscoelastic properties (c).
(b) Determination of storage modulus E 'at 20℃' 20 Is 0.1MPa or more.
(c) Determination of storage modulus E 'at 20℃' 20 Is 0.1MPa to 500 MPa.
The film (4) is prepared by the method that the storage modulus E' 20 Since the hardness after curing is 0.1MPa or more, the workability after curing is improved.
In addition, the film (4) is formed by the steps ofThe viscoelastic properties of (c) above tend to be excellent in acoustic properties such as sound quality and reproducibility when used in acoustic members such as diaphragms. From the viewpoints of acoustic characteristics and handleability after curing, storage modulus E 'at 20℃after curing' 20 More preferably 1MPa or more, still more preferably 2MPa or more, still more preferably 4MPa or more, still more preferably 400MPa or less, still more preferably 300MPa or less, still more preferably 200MPa or less, particularly preferably 100MPa or less, and most preferably 50MPa or less.
The present film (4) preferably has the following viscoelastic properties (d) in a cured state.
(d) Determination of storage modulus E 'at 100℃' 100 Is 0.1MPa to 500 MPa.
The film (4) is prepared by setting the storage modulus E 'after curing' 100 In the above range, heat resistance is improved, and excellent acoustic characteristics are expected even in a high-temperature environment.
Storage modulus E' 100 More preferably 1MPa or more, still more preferably 1.5MPa or more, still more preferably 2.5MPa or more, still more preferably 400MPa or less, still more preferably 300MPa or less, still more preferably 200MPa or less, particularly preferably 100MPa or less, and most preferably 50MPa or less.
The present film (4) preferably has the following viscoelastic properties (e) in a cured state.
(e) The storage modulus E' 100 Relative to the storage modulus E' 20 Ratio (E ')' 100 /E’ 20 ) Is 0.4 to 1.0.
By making the ratio of storage modulus (E' 100 /E’ 20 ) In the above range, the elastic modulus change due to the temperature change tends to be reduced, and the heat resistance tends to be improved. Further, since the change in elastic modulus upon heating is small, the sound quality in a high-temperature environment is not easily lowered, and the reproducibility of sound from a low-temperature region to a high-temperature region is easily made excellent.
The above ratio (E' 100 /E’ 20 ) BetterThe content is selected to be 0.5 or more, more preferably 0.6 or more, and still more preferably 0.65 or more. Further, it is more preferably 0.99 or less, still more preferably 0.97 or less, still more preferably 0.95 or less, and particularly preferably 0.93 or less.
(elongation at Break under tension)
In the cured state, the tensile elongation at break of the film (4) is preferably 100% or more, more preferably 200% or more, and still more preferably 300% or more. If the tensile elongation at break is within this range, the toughness of the film becomes high, and breakage due to vibration over a long period of time is less likely to occur, and durability when used in an acoustic member such as a diaphragm tends to be excellent. The higher the tensile elongation at break, the better, and the upper limit is not particularly limited, but is usually 1500% or less.
The storage modulus and the tensile elongation at break may be measured by the methods described in examples, and the storage modulus and the tensile elongation at break in the cured state may be measured on a film cured so that the gel fraction of the entire film (4) is 80% or more. Specific examples of the method for curing the film (4) so that the gel fraction is 80% or more include heat-based curing and radiation-based curing.
In the case of curing by heating, the heating temperature at the time of curing is preferably 180 ℃ or more and 260 ℃ or less, more preferably 190 ℃ or more and 250 ℃ or less, still more preferably 200 ℃ or more and 240 ℃ or less.
The heating time is preferably 1 second or more and 5 minutes or less, more preferably 5 seconds or more and 4 minutes or less, still more preferably 10 seconds or more and 3 minutes or less, and particularly preferably 20 seconds or more and 2 minutes or less.
The pressure during heating is preferably 0.01MPa to 100MPa, more preferably 0.1MPa to 50 MPa.
On the other hand, in the case of curing by radiation, as the radiation for crosslinking by radiation, electron rays, X-rays, gamma rays, or the like can be used, and the film (4) can be cured to a gel fraction of 80% or more by adjusting the kind of the radiation used and the cumulative irradiation dose.
Further, as described in the examples, the details of the method for measuring the storage modulus and the tensile elongation at break may be such that TD (the direction perpendicular to the flow direction (MD) of the resin) is measured when the film has directionality.
As described above, the film (4) is curable by having curability at least in the intermediate layer. The film (4) may be any one of photo-curable, moisture-curable, thermosetting, etc., but is preferably thermosetting. The film (4) has thermosetting properties, and can be cured when shaping is performed while heating, so that the shaping property is better. Since the film (4) has curability, the gel fraction increases by heating. In addition, the film (4) may have thermosetting properties at least in the intermediate layer, but the outermost layer and the innermost layer may have thermosetting properties as appropriate.
The present film (4) preferably has a crosslinked structure. The film (4) has a crosslinked structure, so that the shape retention before curing (i.e., before molding) is easily improved. In addition, the present film (4) preferably has a crosslinked structure at least at the outermost layer and the innermost layer. By providing the outermost layer and the innermost layer with a crosslinked structure, the shape retention before curing can be easily improved without significantly impairing the flexibility of the film. In addition, by providing the outermost layer and the innermost layer with a crosslinked structure, the gel fraction of the outermost layer and the innermost layer can be easily adjusted to be within the above-described desired range.
The thickness of the film (4) is not particularly limited, but is preferably 5 μm or more and 500 μm or less, more preferably 15 μm or more and 400 μm or less, and still more preferably 30 μm or more and 300 μm or less. If the thickness of the film is within this range, a molded article suitable for the thickness of the acoustic member, particularly the vibration plate, can be produced.
The thickness of the intermediate layer is not particularly limited, but is preferably 3 μm or more and 300 μm or less, more preferably 5 μm or more and 200 μm or less, and still more preferably 20 μm or more and 150 μm or less. By setting the thickness of the intermediate layer to the lower limit value or more, an uncured portion having a constant thickness or more and high flexibility is provided in the film (4), so that the formability is improved and the follow-up property to the mold during forming is easily improved. In addition, by setting the upper limit value or less, it is possible to prevent the portion having high flexibility from becoming thicker beyond necessity, and to easily improve shape retention before molding. The thickness of the intermediate layer is the total thickness when the intermediate layer is 2 or more layers.
The ratio of the thickness of the intermediate layer to the thickness of the entire film (intermediate layer/entire film) is preferably 4/10 or more, more preferably 5/10 or more, and still more preferably 6/10 or more. By setting the ratio of the thicknesses (the intermediate layer and the entire film) to be equal to or greater than the lower limit, a portion having high flexibility is provided in the film at a ratio equal to or greater than a predetermined ratio, and therefore, formability and follow-up performance with respect to a mold during forming can be easily improved. The ratio of the thickness (the whole of the intermediate layer/the film) is preferably 9.9/10 or less, more preferably 9.8/10 or less, and still more preferably 9.7/10 or less. By setting the thickness ratio (the whole of the intermediate layer/film) to be equal to or less than the upper limit value, it is easy to set the thickness of the outermost layer and the innermost layer to be equal to or greater than a predetermined value.
The thickness of each of the outermost layer and the innermost layer is not particularly limited, but is preferably 1 μm or more and 100 μm or less, more preferably 1 μm or more and 60 μm or less, and still more preferably 1 μm or more and 30 μm or less. By setting the thickness of each of the outermost layer and the innermost layer to the above lower limit value or more, the shape retention before molding can be improved, and adhesion to the mold can be easily prevented. Further, by setting the upper limit value or less, it is possible to prevent a portion having a certain hardness or more from becoming thicker than necessary, and it is easy to improve the formability and the follow-up property to the mold during forming.
The thickness of each of the outermost layer and the innermost layer may be smaller than that of the above-mentioned intermediate layer, and the ratio of the thickness of each of the outermost layer and the innermost layer to that of the intermediate layer (each of the outermost layer and the innermost layer/intermediate layer) is preferably 1/50 or more and less than 1. If the thickness of each of the outermost layer and the innermost layer is smaller than the thickness of the intermediate layer, the part of the film having high flexibility is contained in a certain thickness ratio, and therefore, the formability and the follow-up property to the mold at the time of forming are easily improved. In addition, if the ratio (the outermost layer and the innermost layer/intermediate layer) is equal to or higher than the lower limit value, the shape retention before molding is easily improved, and adhesion to the mold is also easily prevented.
From these viewpoints, the ratio (the outermost layer and the innermost layer/intermediate layer) is preferably 1/50 or more and 3/5 or less, more preferably 1/50 or more and 2/5 or less.
The intermediate layer and the outermost and innermost layers of the film (4) are resin layers, respectively, and the resin constituting each resin layer is preferably a curable resin, more preferably a thermosetting resin. Among them, preferable specific examples include epoxy resins, polyurethane resins, silicone resins, acrylic resins, phenolic resins, unsaturated polyester resins, polyimide resins, melamine resins, and the like. In each layer of the present film (4), 1 kind of these resins may be used alone, and 2 or more kinds of these resins are preferably used in combination.
In the present film (4), the same type of resin may be used for each layer (intermediate layer, outermost layer, innermost layer), or different types of resin may be used, but the same type of resin is preferably used for the intermediate layer and the outermost layer. That is, for example, in the case where a silicone resin is used for the intermediate layer, a silicone resin may be used for the outermost and innermost layers. By using the same kind of resin, the layers (for example, the intermediate layer and the outermost layer, and the intermediate layer and the innermost layer) can be easily bonded to each other without using an adhesive layer or the like.
The present film (4) is preferably a silicone film. The silicone film is a film using a silicone resin as a resin, and it is particularly preferable to use a silicone resin in all of the intermediate layer, the outermost layer, and the innermost layer. When the film (4) is a silicone film, heat resistance, mechanical strength, and the like are excellent, and the viscoelastic properties (a) to (e) are easily satisfied. The tensile elongation at break and the coefficient of static friction are also easily adjusted to the desired ranges.
(organopolysiloxane)
The silicone resin used for the intermediate layer, the outermost layer, and the innermost layer includes organopolysiloxane.
The organopolysiloxane has, for example, a structure represented by the following formula (I).
R n SiO (4-n)/2 ···(I)
Here, R may be the same or different and is a substituted or unsubstituted monovalent hydrocarbon group, preferably a monovalent hydrocarbon group having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, and n is a positive number of 1.95 to 2.05.
R may be, for example, as follows: alkyl groups such as methyl, ethyl, propyl, butyl, hexyl, and dodecyl; cycloalkyl groups such as cyclohexyl; alkenyl groups such as vinyl, allyl, butenyl, and hexenyl; aryl groups such as phenyl and tolyl; aralkyl groups such as beta-phenylpropyl; and chloromethyl, trifluoropropyl, cyanoethyl, and the like, in which part or all of the hydrogen atoms bonded to carbon atoms of these groups are substituted with halogen atoms, cyano groups, and the like.
The organopolysiloxane is also preferably terminated at the molecular chain end with trimethylsilyl, dimethylvinyl, dimethylhydroxysilyl, trivinylsilyl, or the like. In addition, the organopolysiloxane preferably has at least 2 alkenyl groups in the molecule. Specifically, R preferably has an alkenyl group of 0.001 mol% or more and 5 mol% or less, preferably 0.005 mol% or more and 3 mol% or less, more preferably 0.01 mol% or more and 1 mol% or less, particularly preferably 0.02 mol% or more and 0.5 mol% or less, and particularly preferably has a vinyl group. The organopolysiloxane is a substantially linear diorganopolysiloxane, but may also be partially branched. In addition, the compound may be a mixture of 2 or more kinds of compounds having different molecular structures.
In the outermost layer and the innermost layer, the organopolysiloxane may be crosslinked by a crosslinking agent or the like, preferably by an organic peroxide. Therefore, the outermost layer and the innermost layer are each preferably a cured product obtained by curing a resin composition containing a crosslinking agent such as an organopolysiloxane and an organic peroxide. In this case, the outermost layer and the innermost layer may be cured so that the gel fraction falls within the above-described desired range. Therefore, the organic peroxide compounded in the outermost layer and the innermost layer is substantially decomposed, and the organic peroxide is not contained in the outermost layer and the innermost layer, respectively, or is contained in a small amount even if it is contained.
On the other hand, in the intermediate layer, the organopolysiloxane may be in an uncrosslinked state or in a partially crosslinked state even if crosslinked. Therefore, the intermediate layer is preferably formed of a resin composition having a crosslinking agent such as an organopolysiloxane and an organic peroxide, and in this case, the intermediate layer may be in an uncured or semi-cured state even if cured so that the gel fraction falls within the above-described desired range. Therefore, the organic peroxide compounded in the intermediate layer can be contained in the intermediate layer with little decomposition in the state of the organic peroxide.
Examples of the organic peroxide include: organic peroxides such as dialkyl peroxides, e.g., di-t-butyl peroxide, 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexane, and 2, 5-dimethyl-2, 5-bis (t-butylperoxy) hexane, and aralkyl peroxides, e.g., 2, 4-dicumyl peroxide, are preferable from the viewpoints of crosslinking rate and safety, and 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexane is particularly preferable.
The amount of the organic peroxide to be blended in the resin composition for forming each of the intermediate layer, the outermost layer and the innermost layer is preferably 0.01 mass% or more and 10 mass% or less, more preferably 0.03 mass% or more and 5 mass% or less, still more preferably 0.05 mass% or more and 4 mass% or less, particularly preferably 0.1 mass% or more and 3 mass% or less, and particularly preferably 0.3 mass% or more and 2 mass% or less, based on the total amount of the resin composition. When the blending amount of the organic peroxide is within this range, a composition having a sufficient curing speed tends to be obtained safely. The organic peroxide blended in the resin composition is substantially decomposed in the outermost layer and the innermost layer as described above, and is hardly contained in the intermediate layer, but the organic peroxide may be contained in the above-described blending amount range.
The resin composition is preferably a kneading type containing an organopolysiloxane. The kneaded resin composition is not liquid (for example, solid or paste) without fluidity at room temperature (25 ℃) in an uncured state, but can be uniformly mixed by a kneader described later. In the present film (4), by using a kneading type resin composition, productivity in processing the resin composition into an intermediate layer, or an outermost layer and an innermost layer becomes good as will be described later.
In the above, the resin composition used for each of the intermediate layer, the outermost layer and the innermost layer may be a resin other than a silicone resin (organopolysiloxane) as described above, and in this case, the outermost layer and the innermost layer may be, for example, layers obtained by curing a resin composition containing a resin and a crosslinking agent so that the gel fraction falls within a desired range. The intermediate layer may be formed of a resin composition containing a resin and a crosslinking agent, and in this case, the resin composition may be uncured or semi-cured even if cured so that the gel fraction falls within the above-mentioned predetermined range.
The intermediate layer, the outermost layer, and the innermost layer of the present invention may each contain a filler such as a silica-based filler. The film (4) can easily bring the mechanical properties such as storage modulus and tensile elongation at break of the film into proper ranges by incorporating the filler in each layer. In addition, by using the filler, the viscosity and hardness of the resin composition can be easily adjusted, and the balance between the fluidity and secondary processability of the resin composition can be easily optimized. Further, there is an advantage that the hardness can be easily adjusted appropriately according to the design and acoustic characteristics of the acoustic member.
The filler forms a part of the gel component in the measurement of the gel fraction, and the gel fraction of each layer is increased by containing the filler. The hardness of each layer can be improved by containing the filler to increase the gel fraction as in the case of increasing the gel fraction by crosslinking.
Examples of the silica-based filler include fumed silica and precipitated silica, and may be a silica-based filler surface-treated with a silane coupling agent.
The content of the filler in each layer is, for example, 10 mass% or more and 50 mass% or less, preferably 15 mass% or more and 40 mass% or less, and more preferably 20 mass% or more and 35 mass% or less, based on the total amount of the resin composition constituting each layer. The average particle diameter of the filler is, for example, 0.01 μm or more and 20 μm or less, preferably 0.1 μm or more and 10 μm or less, and more preferably 0.5 μm or more and 5 μm or less. The average particle diameter of the filler can be measured as the median particle diameter (D50) using a particle size distribution measuring apparatus based on a laser diffraction method or the like.
In the present invention, the resin composition for forming each layer may contain various additives such as a heat stabilizer, an antioxidant, an ultraviolet absorber, a light stabilizer, an antibacterial/antifungal agent, an antistatic agent, a lubricant, a pigment, a dye, a flame retardant, an impact resistance improver, and the like within a range that does not impair the effect.
In the present film (4), the resin compositions for forming the outermost layer and the innermost layer may have the same composition or may have different compositions. Likewise, the resin composition used to form the intermediate layer may have the same composition as the resin composition used to form the outermost layer and the innermost layer, or may have a different composition. The composition of the resin composition as used herein refers to the composition of the resin composition before curing.
In the present invention, commercially available organopolysiloxanes can be used. In addition, a commercially available product containing a mixture of additives such as a silica-based filler in addition to the organopolysiloxane can also be used. Specifically, trade names "KE-597-U", "KE-594-U", etc. manufactured by Xinyue chemical industries, inc. may also be used.
[ film with Release film ]
The present film (4) is provided with a release film, and can be used as a film with a release film. The film with a release film is provided with the film (4) and a release film provided on at least one side of the film (4).
In addition, in the film with a release film, the release film is preferably provided on both sides of the present film (4). The release film is laminated on the outermost layer, the innermost layer, or both of the present film (4).
The release film may be a resin film or a film having a release layer formed by a release treatment on at least one side of a resin film. When the release film has a release layer, the release layer may be laminated on the present film (4) so as to be in contact with the outermost layer and the innermost layer of the present film (4).
As the resin used for the resin film, there may be exemplified: polyolefin resins such as polypropylene, acrylic resins, polystyrene resins, polyacetal resins, polyamide resins, polyester resins, polycarbonate resins, ABS resins, polyether ether ketone resins, and the like. Among these, polyester-based resins are preferable, and among them, polyethylene terephthalate-based resins are preferable.
The thickness of the release film is not particularly limited, but is preferably 5 μm or more and 100 μm or less, more preferably 7 μm or more and 80 μm or less, and still more preferably 10 μm or more and 50 μm or less.
The film (4) is protected by the release film. Therefore, damage to the film (4) during transportation or the like is prevented. As described later, the release film may be used as it is, and may be laminated on the outermost layer and the innermost layer at the time of producing the present film (4), or may be laminated separately on the present film (4) after production.
The present film (4) is molded by, for example, shaping as described later, but the mold release film may be peeled off from the present film (4) at the time of molding and then placed in a mold such as a metal mold. The film (4) has a predetermined outermost layer and innermost layer as described above even without a release film, so that it has good shape retention before curing and can be prevented from sticking to a mold during molding.
[ method for producing the film (4) ]
The film (4) can be formed by a general forming method, for example, by lamination, extrusion such as coextrusion, coating, or a combination thereof. Among these, laminate molding is preferable in view of ease of multilayering of the outermost layer and the innermost layer with the intermediate layer.
In the case of using lamination molding, the outermost layer and the innermost layer may be prepared first, and an intermediate layer may be laminated between the outermost layer and the innermost layer.
More specifically, first, a resin composition for obtaining the top layer and the bottom layer (resin composition for the top layer or bottom layer) and a resin composition for obtaining the intermediate layer (resin composition for the intermediate layer) may be prepared.
The resin compositions are not particularly limited, and may be obtained by kneading materials constituting the resin compositions, for example. As the kneading machine used for kneading, known kneading machines such as extruders such as single screw and twin screw extruders, twin roll and three roll calender rolls, roll mills, plastomill, banbury mixer, kneader and planetary mixer can be used.
The kneading temperature is appropriately adjusted depending on the kind of the resin, the mixing ratio, the presence or absence of the additive, and the kind of the additive, and in order to suppress crosslinking (curing) and appropriately reduce the viscosity of the resin to facilitate kneading, it is preferably 20 ℃ or higher and 150 ℃ or lower, more preferably 30 ℃ or higher and 140 ℃ or lower, still more preferably 40 ℃ or higher and 130 ℃ or lower, particularly preferably 50 ℃ or higher and 120 ℃ or lower, and particularly preferably 60 ℃ or higher and 110 ℃ or lower.
The kneading time is not particularly limited as long as the materials constituting the resin composition are uniformly mixed, and is, for example, several minutes to several hours, preferably 5 minutes to 1 hour.
The resin composition for the outermost layer or the innermost layer prepared as described above may be laminated on a release film by a usual method to obtain a laminate, and then the laminate may be heated to cure the resin composition. Thus, a laminate (hereinafter also referred to as "laminate film") in which the outermost layer or the innermost layer is laminated on the release film is obtained. In the laminated film, the outermost layer or innermost layer is cured to form a crosslinked structure, and the gel fraction is preferably 80% or more as described above.
In the case where the release film has a release treated surface, the resin composition for the outermost layer and the innermost layer may be laminated on the release treated surface of the release film.
Alternatively, the resin composition for the outermost layer or the innermost layer may be laminated between 2 release films, and then the resin composition may be cured by heating or the like as appropriate, and then one release film may be peeled off to obtain the above laminated film.
In the present production method, as described above, the resin composition for the top layer and the bottom layer is laminated on the release film and cured, whereby the surfaces of the top layer and the bottom layer obtained have a shape corresponding to the surface shape of the release film. Therefore, by adjusting the surface shape of the release film, the surface shapes of the outermost layer and the innermost layer can be adjusted.
Next, an intermediate layer formed of the intermediate layer resin composition may be laminated between the laminated films by lamination molding, thereby obtaining the present film (4). Specifically, the resin composition for an intermediate layer is put between laminated films which are discharged from two directions between a pair of rolls, for example, in an uncured or semi-cured state. Here, the resin composition for the intermediate layer may be fed between the laminated films by extrusion from a T die or the like using an extruder or the like, for example. The laminated films may be discharged such that the outermost layer and the innermost layer are positioned inward and face each other.
The thickness is adjusted by the gap between the rolls as needed, and a laminate in which an intermediate layer in an uncured or semi-cured state is formed between the laminated films is obtained. The laminate may have a laminate structure of a release film/an outermost layer/an intermediate layer/an innermost layer/a release film, and may be the film with a release film.
[ molded article ]
The film (4) can be molded into a molded article by molding and curing with a mold such as a die, and typically can be molded into various molded articles by molding with a mold. The curing may be performed according to the characteristics of the present film (4), and may be performed by heating, light irradiation, moisture imparting, or a combination thereof, but is preferably performed by heating. The molded article is preferably an acoustic member, and among them, a vibrating plate is more preferably constituted.
When a molded article is obtained from the present film (4), it is preferable to perform at least the following steps 1 and 2.
Step 1: heating the film (4), molding the film by a mold, and curing the film (4)
Step 2: a step of peeling the formed and cured film (4) (i.e., formed article) from the mold
Hereinafter, each step will be described in more detail.
(Process 1)
In step 1, the present film (4) is heated and molded by a mold, and the present film (4) is cured to form a molded article. The molded article may be molded by a mold, thereby being molded into a desired shape. The molding in step 1 is not particularly limited, and may be performed by any molding method such as vacuum molding, pressure forming, and press forming, and among these, press forming is preferable in terms of easier molding.
That is, in step 1, the film is placed on a die to obtain a laminate of the die and the film, which is formed by thermoforming the film, and the film is preferably hot-pressed.
As the mold, a mold corresponding to the molding method may be prepared, and the mold may be provided with irregularities corresponding to the shape of the molded article to be produced. As the mold, a metal mold (metal mold) is typically used, but a resin mold may be used. For example, as described later, if the molded article (acoustic member) has at least any one of a dome shape or a cone shape, a concave-convex corresponding to the dome shape or the cone shape may be provided in the mold. In addition, when the molded article (acoustic member) has a tangential edge on the surface, a concave-convex corresponding to the tangential edge may be provided in the mold.
The film (4) may be provided with a release film as described above, and the film (4) may be set in a mold after the release film is peeled off as described above.
In the step 1, the heated film (4) may be shaped by a mold, for example, the film (4) placed on the mold may be shaped by the mold while being heated, the preheated film (4) may be placed on the mold, and then the film (4) may be shaped by the mold, or the film and the film may be combined. In addition, the film (4) may be heated by any method, for example, in the case of heating a film disposed on a mold, the mold may be heated and heated by heat transfer, or the film may be heated by another method.
The heating temperature at the time of shaping or curing is preferably 180℃to 260℃inclusive, more preferably 190℃to 250℃inclusive, still more preferably 200℃to 240℃inclusive. If the temperature at the time of shaping or curing is within this range, the film (4) tends to be cured at a sufficient rate within a range where it is not deformed by melting with heat.
The shaping time is preferably 1 second or more and 5 minutes or less, more preferably 5 seconds or more and 4 minutes or less, still more preferably 10 seconds or more and 3 minutes or less, and particularly preferably 20 seconds or more and 2 minutes or less. If the heat treatment time at the time of shaping is within this range, the curing tends to be easy and sufficient in a state where productivity is maintained.
The film (4) is preferably cured while being shaped, but is not particularly limited, and may be cured after being shaped. The shaping time is the time for shaping and/or curing the film (4) in the mold, and does not include the time for moving the mold before the shaping is started and after the shaping is completed and the time for releasing the laminate.
(Process 2)
In step 2, the film (4) formed and cured in step 1 is peeled off from the die to obtain a formed product. In the present invention, since the outermost layer and the innermost layer of the film have low static friction coefficients, adhesion of the film to the mold can be prevented even without laminating a release film or the like, and a molded article obtained from the film can be easily peeled from the mold. In addition, since the gel fraction of the intermediate layer of the film is smaller than a certain value, the formability is high, and the film has high follow-up property to the mold. Therefore, the molded article can be manufactured with high molding accuracy.
Further, the film (4) has high shape retention by providing the outermost layer and the innermost layer, and is excellent in handleability even without a release film, and can be easily set in a mold while maintaining the shape of the film even without a release film. Further, since the release film is not laminated, the step of peeling the release film from the molded article can be omitted, and mass production becomes easy.
In the present invention, the gel fraction of the molded article obtained from the film may be 80% or more. When the gel fraction is 80% or more, a molded article having a storage modulus and mechanical strength suitable for an acoustic member can be easily obtained. The gel fraction of the molded article is more preferably 85% or more, particularly preferably 90% or more. The gel fraction of the molded article is not particularly limited as long as it is 100% or less, usually less than 100%, and for example, 99% or less. The gel fraction of the molded article refers to the gel fraction of the entire molded article, and may be measured by sampling in parallel with the thickness direction of the molded article. Details of the method for measuring the gel fraction are as described above.
[ use of film ]
The film of the present invention is preferably used for an acoustic member as described above, wherein it can be suitably used for a vibration plate. The acoustic member of the present invention is formed by curing the present film (4), and specifically can be formed from the above-described molded article. The diaphragm is more preferably a speaker diaphragm, and is particularly preferably used as a micro speaker diaphragm for a mobile phone or the like.
The film (4) can be formed into various acoustic members such as a diaphragm by suitable molding.
The acoustic member may, for example, have at least a portion thereof have a dome shape, a cone shape, or the like. In addition, the acoustic member may have tangential edges at its surface. In the case of having a dome shape or a cone shape, or having a tangential edge, the acoustic member is preferably used for a diaphragm, more preferably for a speaker diaphragm.
(vibrating plate)
The shape of the diaphragm is not particularly limited, and circular, elliptical, oval, or the like may be selected. In addition, the vibration plate generally has a main body that vibrates according to an electric signal or the like and an edge surrounding the periphery of the main body. The body of the diaphragm is typically edge supported. The shape of the diaphragm may be dome-shaped or cone-shaped as described above, or may be a combination of these, or may be another shape used in the diaphragm.
The film (4) may be formed as long as at least a part of the diaphragm, and for example, the body or the edge of the diaphragm may be formed of the film (4) and the edge or the body of the diaphragm may be formed of other members. Of course, both the main body and the edge may be integrally formed of the film (4), or the entire diaphragm may be formed of the film (4).
Fig. 1 is a diagram showing the structure of a diaphragm 1 according to an embodiment of the present invention, which is the same as the structure described in the present film (1).
Fig. 2 is a diagram showing a structure of a diaphragm 11 according to another embodiment of the present invention, which is the same as that described in the present film (1).
Fig. 3 is a plan view of a diaphragm 21 according to still another embodiment of the present invention, and fig. 3 is the same as that described in the present film (1).
As described above, the diaphragm is preferably a speaker diaphragm, and among them, a micro speaker diaphragm is preferable. From the viewpoint of being suitable for use as a micro-speaker diaphragm, a diaphragm having a maximum diameter of 25mm or less, preferably 20mm or less, and a maximum diameter of 5mm or more is suitably used as the size of the diaphragm. The maximum diameter is a diameter when the shape of the diaphragm is a circular shape, and is a long diameter when the shape of the diaphragm is an elliptical shape or an oval shape.
The diaphragm may be formed of the present film (4) alone or may be formed of a composite material of the present film (4) and other members. For example, either the edge or the body may be formed of other members as described above.
Further, in order to adjust the secondary working adaptability, dust resistance, acoustic characteristics, and the like of the vibration plate, and to improve the appearance, the surface of the vibration plate may be appropriately subjected to a treatment such as further coating with an antistatic agent, vapor deposition of a metal, sputtering, or coloring (black, white, or the like). Further, lamination with a metal such as aluminum, lamination with a nonwoven fabric, or the like may be suitably performed.
(Acoustic transducer)
The acoustic transducer of the present invention is an acoustic transducer including the acoustic member, preferably a diaphragm. As the acoustic transducer, typically an electroacoustic transducer, a speaker, a receiver, a microphone, an earphone, and the like are exemplified. Among these, the acoustic transducer is preferably a speaker, and is preferably a micro speaker of a mobile phone or the like.
Examples
The present invention will be described in detail with reference to examples, but the present invention is not limited thereto.
[ evaluation and measurement method ]
In this example, various physical properties and film evaluations were performed as follows. The term "present film" refers to all of the present films (1) to (4).
(1) Determination of gel fraction
(1-1) the present films (1) and (2)
The gel fraction of the film before and after the press molding was measured by the following method. The gel fraction is calculated as a gel component including not only the crosslinking component contained in the film but also insoluble components other than the crosslinking component such as the filler, as will be apparent from the following measurement method.
(A) The sample was equally cut parallel to the thickness direction of the film, and about 100mg of the sample was collected, and the mass (a) of the sample was measured.
(B) The samples taken were immersed in chloroform at 23℃for 24 hours.
(C) The solid content in chloroform was removed, and dried under vacuum at 50℃for 7 hours.
(D) The mass (b) of the dried solid content was measured.
(E) The gel fraction was calculated based on the following formula (i) using the masses (a) and (b).
(1-2) the present film (3)
The gel fraction of the whole film before curing, the gel fractions of the outermost layer and the innermost layer of the film before curing, and the gel fraction of the whole film after curing were measured according to the method described in the specification. When the gel fraction of the whole film was measured, the sample was cut in a direction parallel to the thickness direction of the film. The intermediate layer of the present film before curing was calculated from the gel fraction of the entire present film before curing and the outermost layer and the innermost layer, and the ratio of the layer thicknesses.
(1-3) present film (4)
The gel fraction of the whole film before curing, the gel fractions of the outermost layer and the innermost layer of the film before curing, and the gel fraction of the whole film after curing were measured according to the method described in the specification. When the gel fraction of the whole film was measured, the film was sampled uniformly in parallel with the thickness direction of the film. The intermediate layer of the film (4) before curing was calculated from the gel fraction of the entire film (4) before curing and the outermost layer and the innermost layer, and the ratio of the layer thicknesses.
(2) Storage modulus E'
(2-1) the present films (1) and (2)
Test pieces of 4 mm. Times.8 cm were cut out from the present films (1) and (2) obtained in each of examples and comparative examples, and obtained as measurement samples. Using the measurement sample, the test piece was prepared according to JIS K7244-4:1999, using a viscoelastometer "DVA-200 (manufactured by IT instruments control Co., ltd.), the measurement mode was set to stretching, and the temperature was raised at a frequency of 10Hz, strain of 0.1%, and a temperature range of 0 to 300℃at a heating rate of 3℃per minute, and storage moduli at 20℃and 100℃were measured.
The measurement of the storage modulus at 20℃was performed on the film before and after the press molding. After the press molding, the storage modulus at 100℃was also measured.
(2-2) present film (3)
Test pieces of 4mm X8 cm were cut out from the present film (3) before and after curing obtained in each of examples and comparative examples, and obtained as measurement samples. Using the measurement sample, the test piece was prepared according to JIS K7244-4:1999, measurement was performed using a viscoelastometer "DVA-200 (manufactured by IT meter control Co., ltd.). The film before press molding was stretched in a measurement mode, and the storage modulus at 20℃was measured by raising the temperature at a frequency of 10Hz and a strain of 0.1% at a temperature in the range of-100 to 300℃and a heating rate of 3℃per minute. The film after press molding was heated at a frequency of 10Hz, a strain of 0.1%, a temperature range of-100 to 300℃and a heating rate of 3℃per minute, and storage moduli at 20℃and 100℃were measured. The measurement was performed on TD.
(2-3) present film (4)
Test pieces of 4 mm. Times.8 cm were cut out from the present film (4) before and after curing obtained in each of examples and comparative examples, and obtained as measurement samples. Using the measurement sample, the test piece was prepared according to JIS K7244-4:1999, using a viscoelasticity spectrometer "DVA-200 (manufactured by IT meter control Co., ltd.), the measurement mode was set to stretching, and the storage modulus at 20℃was measured for the film before curing by heating at a frequency of 10Hz, a strain of 0.1% and a temperature range of 0 to 300℃at a heating rate of 3℃per minute. In addition, storage modulus at 20℃and 100℃was measured for the cured film. The measurement was performed on TD.
(3) Coefficient of static friction (surface coefficient of friction)
(3-1) the present films (1) and (2)
The static friction coefficients of the outermost surface and innermost surface of the present film obtained in each of examples and comparative examples with a stainless steel plate (SUS 430) were measured. The static friction coefficient was measured 2 times for the outermost surfaces of the films before thermoforming obtained in each of examples and comparative examples, and the average value thereof was determined. The specific measurement method of the static friction coefficient is as follows.
Reference is made to JIS K7125:1999, after the surface of the present film was kept in contact with the stainless steel plate for 15 seconds before the start of the test, the static friction coefficient with the stainless steel plate was evaluated by performing measurement in the Machine Direction (MD) under the following conditions.
Device: plastic film sliding tester (manufactured by INTESCO corporation)
Slide: total mass 200g (square with contact area of 63mm on one side)
Contact area: 400cm 2
Test speed: 100mm/min
Temperature: 23 ℃ +/-2 DEG C
Relative humidity: 50% ± 10%
(3-2) present film (4)
The static friction coefficients of the outermost surface and innermost surface of the present film obtained in each of examples and comparative examples with a stainless steel plate (SUS 430) were measured. The static friction coefficients were measured 3 times for the outermost surface and innermost surface of the film before thermoforming obtained in each of examples and comparative examples, respectively, and the average value thereof was determined. The specific measurement method of the static friction coefficient is as follows.
Reference is made to JIS K7125:1999, after the outermost surface or innermost surface of the present film was allowed to contact with the stainless steel plate for 15 seconds before the start of the test, the static friction coefficient with the stainless steel plate was evaluated by performing measurement in the Machine Direction (MD) under the following conditions.
Device: plastic film sliding tester (manufactured by INTESCO corporation)
Slide: total mass 200g (square with contact area of 63mm on one side)
Contact area: 40cm 2
Test speed: 100mm/min
Temperature: 23 ℃ +/-2 DEG C
Relative humidity: 50% ± 10%
(4) Operability of
(4-a) the presence or absence of breakage
(4-a-1) the present films (1), (2) and (4)
In the step of peeling the release film from the film with the release film by hand, the presence or absence of breakage was evaluated. The case where the release film could be peeled without damaging the film was evaluated as "good", and the case where the release film was attached and a part of the film was damaged was evaluated as "x".
The present film from which the release film was peeled was used for various evaluations and measurements other than the presence or absence of breakage.
(4-a-2) the present film (3)
In the case of producing the present film in each of examples and comparative examples, the release film was produced in a state in which the release film was laminated on the outermost surface and the innermost surface. In the step of peeling the outermost surface and the innermost surface of the obtained film by hand from the film before curing, the presence or absence of breakage was evaluated. The case where the release film could be peeled without damaging the film was evaluated as "good", and the case where the release film was attached and a part of the film was damaged was evaluated as "x".
The present film from which the release film was peeled was used for various evaluations and measurements other than the presence or absence of breakage.
(4-b) shape retentivity
The shape retention of the present film before curing obtained in each of examples and comparative examples was evaluated. When the present film was peeled from the release film and used for various evaluations and measurements, the case where the film could be easily handled because of the shape retention was evaluated as "good", and the case where the film could not be held and thus was deflected during handling, and the film itself was wound or broken was evaluated as "x".
(5) Formability/shaping property
(5-1) the present films (1) and (2) (formability)
Test pieces of about 7 cm. Times.10 cm were cut out from the present films obtained in each of examples and comparative examples, and the test pieces were used as evaluation samples. The evaluation sample was placed in a mold for a dome-shaped vibration plate with a tangential edge, which was preheated to 230 ℃, and pressurized at a pressure of 0.1MPa, and the sample was taken out of the mold after being held in the pressurized state for 20 seconds.
The samples after the removal were visually checked, and the samples having the irregularities such as those formed in the metal mold were evaluated as "good", and the samples having only the irregularities smaller than the metal mold were evaluated as "x".
(5-2) present film (3)
Test pieces of about 7 cm. Times.10 cm were cut out from the present films obtained in each of examples and comparative examples, and the test pieces were used as evaluation samples. The evaluation sample was placed in a mold for a dome-shaped vibration plate with a tangential edge, which was preheated to 230 ℃, and pressurized at a pressure of 0.1MPa, and the sample was taken out of the mold after being held in the pressurized state for 20 seconds.
(5-3) present film (4)
Test pieces of about 7 cm. Times.10 cm were cut out from the present films obtained in each of examples and comparative examples, and the test pieces were used as evaluation samples. The evaluation sample was placed in a mold for a dome-shaped vibration plate with a tangential edge, which was preheated to 230 ℃, and pressurized at a pressure of 0.1MPa, and the sample was taken out of the mold after being held in the pressurized state for 20 seconds.
The samples after the removal were visually checked, and the samples having the irregularities such as those formed in the metal mold were evaluated as "good", and the samples having only the irregularities smaller than the metal mold were evaluated as "x".
(6) Adhesion to metal mold
(6-1) the present films (1), (2) and (4)
Test pieces of about 7cm×10cm were cut out from the present films obtained in each example and comparative example as evaluation samples in the same manner as in the above-described evaluation of formability/shapability. The evaluation sample was placed in a mold for a vibration plate preheated to 230℃and pressurized at a pressure of 0.1MPa, and the sample was taken out of the mold after being held in the pressurized state for 20 seconds.
The evaluation sample was evaluated as "good" when the evaluation sample was taken out of the mold, and the evaluation sample was not adhered to the mold but was easily taken out, and was evaluated as "x" when the evaluation sample was adhered to the mold and was involved.
(6-2) present film (3)
Test pieces of about 7cm×10cm were cut out from the present films obtained in each example and comparative example as evaluation samples in the same manner as in the above-described evaluation of formability/shapability. The evaluation sample was placed in a mold for a vibration plate preheated to 230℃and pressurized at a pressure of 0.1MPa, and the sample was taken out of the mold after being held in the pressurized state for 20 seconds.
(7) Elongation at tensile break
By following JIS K7161:2014, and measuring elongation at break of the cured film in TD at a stretching speed of 200 mm/min and at 23 ℃.
(8) Surface roughness (Ra)
The roughened surface of the release film was measured in the machine direction of the film using a contact surface roughness meter Surf reader ET4000A (manufactured by sakun research corporation) under conditions of a stylus tip radius of 0.5mm, a measurement length of 8.0mm, a sampling length of 8.0mm, a cut-off value of 0.8mm, and a measurement speed of 0.2 mm/sec, and an arithmetic average roughness (Ra) was calculated.
Example 1-1
< raw materials >
Silicone rubber (a-1): mixtures of organopolysiloxanes with silica. (trade name "KE-597-U", xinyue chemical industry Co., ltd.)
The organic peroxide composite silicone rubber (B-1) is hereinafter abbreviated as "organic peroxide". ): silicone rubber (trade name "C-8B", manufactured by Xinyue chemical Co., ltd.) containing about 40% of 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexane
100 parts by mass of silicone rubber (A-1) and 1 part by mass of organic peroxide (B-1) as raw materials were kneaded at a temperature of 90℃for 5 minutes using a mixer to obtain a kneaded resin composition (1). As a release film, a PET film (1) having a surface roughness (Ra) of 0.98 μm on the rough surface was prepared and fed along 2 calender rolls having a diameter of 100mm with the rough surface inside. The resin composition (1) was put between release films, and the rolls were set at a roll temperature of 90℃to form banks, and the thickness of the resin composition (1) was adjusted to 100. Mu.m, to obtain a silicone film with a release film. The obtained silicone film is irradiated with radiation. After irradiation with radiation, the release films on both sides were peeled off to obtain a sample of the silicone film. For the obtained sample, it was assumed that a molded article was produced by molding, and cured by a simple method of press molding with 2 flat plates at a pressure of 0.2MPa while heating at 200 ℃ for 2 minutes. For this sample before press molding, the surface friction coefficient, gel fraction and storage modulus were measured, and the handling property, formability and adhesion to a metal mold were evaluated. The gel fraction and storage modulus of the present sample after press molding were measured. The results are set forth in Table 1.
In addition, the surface friction coefficient of the sample did not change before and after pressurization.
Comparative example 1-1
A sample was obtained in the same manner as in example 1-1, except that the heat treatment was performed at 200℃for 2 minutes instead of the irradiation of the radiation. For this sample before press molding, the surface friction coefficient, gel fraction and storage modulus were measured, and the handling property, formability and adhesion to a metal mold were evaluated. The gel fraction and storage modulus of the present sample after press molding were measured. The film of comparative example 1-1 was a film having no curability, as can be seen from the gel fraction value.
TABLE 1
TABLE 1
As shown in table 1, the silicone film with a release film of example 1-1 was semi-crosslinked by irradiation with radiation, and thus could be peeled from the release film without breakage, and the shape of the film was properly maintained even after peeling the release film, and the handleability was excellent.
Further, since the film after press molding (after curing) satisfies the viscoelastic properties of the above (b) to (d), when the diaphragm is molded using the film of example 1-1, excellent acoustic properties such as sound quality and reproducibility can be expected.
The present film obtained in example 1-1 was evaluated for formability by the above method, and as a result, it showed formability to such an extent that practical applicability could be tolerated.
In addition, in the evaluation of adhesion to a mold, the present film obtained in example 1-1 was not adhered to the mold even when the evaluation sample was taken out from the mold, and it was easy to take out the evaluation sample.
On the other hand, it was found that the film of comparative example 1-1 was not cured completely, and the film was hard, and the formability was insufficient, and the formability was poor.
Example 2-1
< raw materials >
Silicone rubber (a-1): mixtures of organopolysiloxanes with silica. (trade name "KE-597-U", xinyue chemical industry Co., ltd.)
The organic peroxide composite silicone rubber (B-1) is hereinafter abbreviated as "organic peroxide". ): silicone rubber (trade name "C-8B", manufactured by Xinyue chemical Co., ltd.) containing about 40% of 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexane
100 parts by mass of silicone rubber (A-1) and 1 part by mass of organic peroxide (B-1) as raw materials were kneaded at a temperature of 90℃for 5 minutes using a mixer to obtain a kneaded resin composition (1). As a release film, a PET film (1) having a surface roughness (Ra) of 0.98 μm on the rough surface was prepared and fed along 2 calender rolls having a diameter of 100mm with the rough surface inside. The resin composition (1) was put between release films, and the rolls were set at a roll temperature of 90℃to form banks, and the thickness of the resin composition (1) was adjusted to 100. Mu.m, to obtain a silicone film with a release film. The obtained silicone film is irradiated with radiation. After irradiation with radiation, the release films on both sides were peeled off to obtain a sample of the silicone film. For the obtained sample, it was assumed that a molded article was produced by molding, and cured by a simple method of press molding with 2 flat plates at a pressure of 0.2MPa while heating at 200 ℃ for 2 minutes. For this sample before press molding, the surface friction coefficient, gel fraction and storage modulus were measured, and the handling property, formability and adhesion to a metal mold were evaluated. The gel fraction and storage modulus of the present sample after press molding were measured. The results are set forth in Table 1.
Comparative example 2-1
Samples were obtained in the same manner as in example 2-1, except that a PET film (2) having a surface roughness (Ra) of 0 μm was used as a release film. For this sample before press molding, the surface friction coefficient, gel fraction and storage modulus were measured, and the handling property, formability and adhesion to a metal mold were evaluated. The gel fraction and storage modulus of the present sample after press molding were measured.
Comparative example 2-2
A sample was obtained in the same manner as in example 2-1, except that the heat treatment was performed at 200℃for 2 minutes instead of the irradiation of the radiation. For this sample before press molding, the surface friction coefficient, gel fraction and storage modulus were measured, and the handling property, formability and adhesion to a metal mold were evaluated. The gel fraction and storage modulus of the present sample after press molding were measured.
TABLE 2
TABLE 2
As shown in table 1, the silicone film with a release film of example 2-1 was semi-crosslinked by irradiation with radiation, and thus could be peeled from the release film without breakage, and the shape of the film was properly maintained even after peeling the release film, and the handleability was excellent.
Further, since the film after press molding (after curing) satisfies the viscoelastic properties of the above (b) to (d), when the diaphragm is molded using the film of example 2-1, excellent acoustic properties such as sound quality and reproducibility can be expected.
The present film obtained in example 2-1 was evaluated for formability by the above method, and as a result, it showed formability to such an extent that practical applicability could be tolerated.
In addition, in the evaluation of adhesion to a mold, the present film obtained in example 2-1 was not adhered to the mold even when the evaluation sample was taken out from the mold, and it was easy to take out the evaluation sample.
On the other hand, it was found that the film of comparative example 2-1 had a large surface friction coefficient (static friction coefficient) and was therefore difficult to be removed from the mold and difficult to handle. In addition, it was found that the film of comparative example 2-2 was not cured completely, and the film was hard, and the formability was insufficient, and the formability was poor.
Example 3-1
As a release film, a PET film (1) having a surface roughness (Ra) of 0.88 μm and a PET film (2) having a surface roughness (Ra) of 1.9 μm were prepared. A laminated film obtained by laminating and curing a silicone rubber (trade name: TSE2571-5U, manufactured by Momentive Performance Materials) having a thickness of 20 μm between the PET film (1) and the PET film (2) was prepared, and the PET film (1) was peeled off to expose the cured silicone.
100 parts by mass of a mixture containing organopolysiloxane and silica (trade name "KE-597-U", manufactured by Xinyue chemical Co., ltd.) and 1 part by mass of organic peroxide (trade name "C-8B", manufactured by Xinyue chemical Co., ltd., 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexane, containing about 40 mass% of organic peroxide) were kneaded at a temperature of 90℃for 10 minutes using a planetary mixer to obtain a kneaded resin composition (1).
The 2 laminated films obtained above were fed along 2 calender rolls having a diameter of 100mm with the exposed surface of the silicone as the inner side, a resin composition (1) was put between the calender rolls, and the rolls were set at a room temperature of 25℃and a roll temperature of 90℃to form banks, whereby a film with a release film comprising a release film/the outermost layer/the intermediate layer/the innermost layer/the release film was obtained so that the thickness of the intermediate layer became 100. Mu.m. In addition, the thickness of the outermost layer and the innermost layer was 20. Mu.m.
The 2 release films were peeled under the above conditions, and as a result, peeled without breakage. In addition, shape retention was also good.
The gel fraction and storage modulus at 20℃were measured for the film from which the release film was peeled. The measurement results are shown in Table 1.
Assuming that a molded article is produced by molding, the present film obtained as described above is cured by a simple method of press molding with 2 flat plates at a pressure of 0.2MPa while being heated at 220 ℃ for 2 minutes. The gel fraction (film as a whole), storage modulus at 20℃and 100℃and tensile elongation at break were measured for the obtained cured film. The measurement results are shown in Table 1.
Example 3-2
Instead of the laminated film, the release film (PET film (2)) used in example 3-1 was fed alone along 2 calender rolls having a diameter of 100mm, the resin composition (1) was fed between the calender rolls between the release films, the rolls were formed into banks at a room temperature of 25℃and a roll temperature of 90℃to obtain a film with a release film formed of a release film/a single film/a release film so that the thickness of the resin layer became 100. Mu.m.
The film with the release film was cured by a simple method of press molding with 2 flat plates at a pressure of 0.2MPa while heating at 150 ℃ for 2 minutes, to obtain a film having a storage modulus and a gel fraction as shown in table 1. The 2 release films were peeled under the above conditions, and as a result, peeled without breakage. In addition, shape retention was also good.
The gel fraction and storage modulus at 20℃were measured for the film from which the release film was peeled. The measurement results are shown in Table 1.
Further, the film was subjected to press curing under the same conditions as in example 3-1, and the gel fraction (film as a whole), storage modulus at 20℃and 100℃and tensile elongation at break were measured for the obtained cured film.
Comparative example 3-1
Films having gel fractions shown in Table 1 were obtained in the same manner as in example 3-2 except that the semi-curing was not performed in example 3-2.
In an attempt to peel 2 release films from the obtained film with release film under the above conditions, a part of the film was broken. Therefore, no clear value can be obtained for the storage modulus E'.
The film was cured, and the physical properties after curing were evaluated by the above method. As the curing method, a simple method of press-molding with 2 flat plates at a pressure of 0.2MPa while heating at 220 ℃ for 2 minutes was used for the molding to cure the molded product. The gel fraction, storage modulus at 20℃and 100℃and tensile elongation at break were measured for the obtained cured film.
The evaluation measurement results in example 3-1, example 3-2 and comparative example 3-1 are shown in Table 3 below.
TABLE 3
TABLE 3 Table 3
The film with a release film of example 3-1 having an intermediate layer and outermost and innermost layers, and the outermost and innermost layers being high-cure layers, was able to be peeled from the release film without breakage. Further, since the outermost layer and the innermost layer are relatively hard layers, the shape of the film is properly maintained even after the release film is peeled off, and the handleability is excellent.
Further, since the cured film satisfies the viscoelastic properties of the above (b) to (d), when the diaphragm is molded using the film of example 3-1, excellent acoustic properties such as sound quality and reproducibility can be expected. In addition, the cured film has a high tensile elongation at break, is less likely to break due to long-term vibration, and is expected to provide an acoustic member having excellent durability.
In addition, the film with release film of example 3-2, which is a semi-cured monolayer film, was able to be peeled from the release film without breakage. Further, since the single-layer film is a relatively hard layer, the shape of the film is properly maintained even after the release film is peeled off, and the handleability is excellent.
The present films obtained in examples 3-1 and 3-2 were evaluated for formability/shapability by the above-described method, and as a result, they exhibited formability/shapability to such an extent that practical applicability could be tolerated.
In addition, in the evaluation of adhesion to a mold, the present films obtained in examples 3-1 and 3-2 were easily removed without adhering the evaluation sample to the mold even when the evaluation sample was removed from the mold.
In contrast, the relatively soft release film-attached film of comparative example 3-1 was broken when the release film was peeled off. In addition, it is difficult to properly maintain the shape, and operability is poor.
Further, the film of comparative example 3-1 was evaluated for formability/shapability, and as a result, it showed formability/shapability to such an extent that practical applicability could be tolerated. However, in the evaluation of adhesion to a mold, the evaluation sample adhered to the mold and involved in the adhesion, resulting in a problem.
Example 4-1
For the top and bottom most layers, a PET film (1) having a surface roughness (Ra) of 0.88 μm and a PET film (2) having a surface roughness (Ra) of 1.9 μm were prepared as release films. A laminated film obtained by laminating and curing a silicone rubber (trade name "TSE2571-5U", manufactured by Momentive Performance Materials Co.) having a thickness of 20 μm between the PET film (1) and the PET film (2) was prepared, and the PET film (1) was peeled off to expose the cured silicone.
100 parts by mass of a mixture containing organopolysiloxane and silica (trade name "KE-597-U", manufactured by Xinyue chemical Co., ltd.) and 1 part by mass of organic peroxide (trade name "C-8B", manufactured by Xinyue chemical Co., ltd., 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexane, containing about 40 mass% of organic peroxide) were kneaded at a temperature of 90℃for 10 minutes using a planetary mixer to obtain a kneaded resin composition (1).
The laminated film was fed along 2 calender rolls having a diameter of 100mm with the exposed surface of the cured silicone as the inside, a resin composition (1) was put between the calender rolls, and the rolls were set at a room temperature of 25℃and a roll temperature of 90℃to form banks, whereby a film with a release film comprising a release film/top layer/middle layer/bottom layer/release film was obtained so that the thickness of the middle layer became 100. Mu.m. From the obtained film with a release film, 2 release films were peeled off by hand to obtain the present film. The gel fraction of the top and bottom layers and the intermediate layer of the present film, the static friction coefficients of the top and bottom layers, and the storage modulus of the present film at 20℃were measured. Table 1 shows the measurement results and the evaluation results of operability.
Assuming that a molded article is produced by molding, the present film obtained as described above is cured by a simple method of press molding with 2 flat plates at a pressure of 0.2MPa while being heated at 220 ℃ for 2 minutes. The gel fraction (the whole film), storage modulus and tensile elongation at break of the obtained cured film were measured.
Comparative example 4-1
Instead of the laminated film, a release film (PET film (2)) was fed along 2 calender rolls having a diameter of 100mm, a resin composition (1) was put between the calender rolls, and the rolls were formed into banks at a room temperature of 25℃and a roll temperature of 90℃to obtain a film with a release film formed of a release film/intermediate layer/release film so that the thickness of the intermediate layer became 100. Mu.m.
From the obtained film with a release film, 2 release films were peeled off to obtain the present film. The film is formed of an interlayer monolayer. The gel fraction, the static friction coefficient, and the storage modulus at 20℃of the film (intermediate layer) were measured. Table 1 shows the measurement results and the evaluation results of operability.
The present film obtained as described above was cured by a simple method of press-forming with 2 flat plates at a pressure of 0.2MPa while being heated at 220 ℃ for 2 minutes, assuming that the film was formed. The gel fraction, storage modulus and tensile elongation at break of the obtained cured film were measured.
Comparative example 4-2
Instead of the laminated film, a release film (PET film (2)) was fed along 2 calender rolls having a diameter of 100mm, a resin composition (1) was put between the calender rolls, and the rolls were formed into banks at a room temperature of 25℃and a roll temperature of 90℃to obtain a film with a release film formed of a release film/intermediate layer/release film so that the thickness of the intermediate layer became 100. Mu.m. The film with the release film was heated by a simple method of press molding with 2 flat plates at a pressure of 0.2MPa while heating at 220 ℃ for 2 minutes, thereby curing the intermediate layer.
After the intermediate layer was cured, 2 release films were peeled from the obtained film with release film, to obtain the present film. The film is formed of an interlayer monolayer. The film (interlayer) was measured for its static coefficient of friction and storage modulus at 20 ℃. Table 1 shows the measurement results and the evaluation results of operability.
In addition, since the present film has completed curing, the gel fraction, storage modulus and tensile elongation at break were measured for the present film.
The evaluation measurement results in example 4-1 and comparative examples 4-1 to 4-2 are summarized in Table 4 below.
TABLE 4
"one table" 4
The present film of the above example has a curable intermediate layer, a top layer and a bottom layer, and the static friction coefficient of the top layer and the bottom layer is 3 or less, so that it can be molded sufficiently by molding, has good follow-up property to a mold, and can prevent the film from sticking to the mold during molding. Further, since the outermost layer and the innermost layer are relatively hard layers, the shape of the film is properly maintained even after the release film is peeled off, and the film is excellent in handleability and can be easily set in a metal mold.
Further, since the cured film satisfies the viscoelastic properties of the above (c) to (e), when an acoustic member such as a diaphragm is molded using the film of example 4-1, excellent acoustic properties such as sound quality and reproducibility can be expected. In addition, the cured film has a high tensile elongation at break, is less likely to break due to long-term vibration, and is expected to provide an acoustic member having excellent durability.
In contrast, the film of comparative example 4-1 has a high static friction coefficient on the surface, and therefore, although the formability and the follow-up property to the mold are good, the film is not adhered to the mold during forming. Further, the film is not a multilayer structure having an outermost layer, an innermost layer, and a curable intermediate layer, and the entire film is relatively soft, so that it is difficult to properly maintain the shape after peeling the release film, and the workability is poor.
In comparative example 4-2, the film was not adhered to the mold at the time of molding because of the low static friction coefficient of the surface, but the film had not been a multilayer structure having the outermost layer, the innermost layer, and the curable intermediate layer, and the film was relatively hard as a whole, so that the molding was not performed sufficiently by molding, and the following property to the mold was also insufficient.
Industrial applicability
The molded article obtained from the film of the present invention can be easily taken out from a mold when the molded article is produced, and therefore can be applied to various molded articles. In particular, the film is useful as a film for acoustic members such as a diaphragm, and has great industrial significance.
Claims (73)
1. A single-layer film for acoustic members, which has curability.
2. The film for acoustic member according to claim 1, having a gel fraction of 60% or more and 90% or less.
3. A film for an acoustic member according to claim 1 or 2, which has the viscoelastic properties of (a),
(a) The storage modulus E' at a measurement temperature of 20 ℃ is not less than 0.1MPa and not more than 500 MPa.
4. The film for an acoustic member according to claim 1 or 2, which has thermosetting properties.
5. The film for an acoustic member according to claim 1 or 2, which has a crosslinked structure.
6. The film for an acoustic member according to claim 1 or 2, which has the following viscoelastic properties (b) to (d) in a cured state,
(b) Determination of storage modulus E 'at 20℃' 20 Is 0.1MPa to 500MPa,
(c) Measuring temperature of 100 DEG CLower storage modulus E' 100 Is 0.1MPa to 500MPa,
(d) The storage modulus E' 100 With respect to the storage modulus E' 20 Ratio (E ')' 100 /E’ 20 ) Is 0.2 to 1.0.
7. The film for an acoustic member according to claim 1 or 2, which is a film for a vibration plate.
8. The film for an acoustic member according to claim 1 or 2, which is a silicone film.
9. The film for an acoustic member according to claim 1 or 2, wherein a static friction coefficient of at least one face is 3 or less.
10. An acoustic member obtained by curing the acoustic member according to any one of claims 1 to 9 with a film.
11. A vibration plate obtained by curing the film for an acoustic member according to any one of claims 1 to 9.
12. An acoustic transducer provided with the acoustic member of claim 10.
13. An acoustic transducer provided with the diaphragm of claim 11.
14. The method for producing a film for an acoustic member according to any one of claims 1 to 9, comprising the step of irradiating radiation.
15. The method for producing a film for an acoustic member according to claim 14, wherein the release film is peeled from the resin layer after irradiation of the resin layer laminated on the release film with radiation.
16. The method for producing a film for an acoustic member according to any one of claims 1 to 9, comprising the steps of:
laminating a resin layer between 2 release films having a surface roughness (Ra) of 0.10 to 6.00 [ mu ] m;
a step of curing the laminated resin layers; and
and peeling at least 1 release film from the cured resin layer.
17. A single-layer silicone film having curability and a static friction coefficient of at least one surface of 3 or less.
18. The silicone film according to claim 17, having a gel fraction of 60% or more and 90% or less.
19. The silicone film according to claim 17 or 18, which has the viscoelastic properties of (a),
(a) The storage modulus E' at a measurement temperature of 20 ℃ is not less than 0.1MPa and not more than 500 MPa.
20. The silicone film according to claim 17 or 18, which has thermosetting properties.
21. The silicone film according to claim 17 or 18, which has a crosslinked structure.
22. The silicone film according to claim 17 or 18, which has the following viscoelastic properties (b) to (d) in a cured state,
(b) Determination of storage modulus E 'at 20℃' 20 Is 0.1MPa to 500MPa,
(c) Determination of storage modulus E 'at 100℃' 100 Is 0.1MPa to 500MPa,
(d) The storage modulus E' 100 With respect to the storage modulus E' 20 Ratio (E ')' 100 /E’ 20 ) Is above 0.2And 1.0 or less.
23. The silicone film according to claim 17 or 18, which is a film for an acoustic member.
24. The silicone film according to claim 17 or 18, which is a film for a vibration plate.
25. An organosilicon film with a release film, comprising: the silicone film according to any one of claims 17 to 24, and a release film provided on at least one side of the silicone film.
26. A molded article obtained by curing the silicone film according to any one of claims 17 to 24.
27. An acoustic member obtained by curing the silicone film according to any one of claims 17 to 24.
28. A vibration plate obtained by curing the silicone film according to any one of claims 17 to 24.
29. An acoustic transducer provided with the acoustic member of claim 27.
30. An acoustic transducer provided with the diaphragm of claim 28.
31. The method for producing a silicone film according to any one of claims 17 to 24, comprising a step of irradiating with radiation.
32. The method for producing a silicone film according to claim 31, wherein the release film is peeled from the silicone resin layer after irradiation of the silicone resin layer laminated on the release film with radiation.
33. The method for producing a silicone film according to any one of claims 17 to 24, comprising the steps of:
a step of laminating a silicone resin layer between 2 release films having a surface roughness (Ra) of 0.10 to 6.00 [ mu ] m;
a step of curing the laminated silicone resin layers; and
And a step of peeling at least 1 release film from the cured silicone resin layer.
34. A film for an acoustic member, which is a film having curability and has the following viscoelastic properties (a),
(a) The storage modulus E' at a measurement temperature of 20 ℃ and a frequency of 10Hz is not less than 0.1MPa and not more than 500 MPa.
35. The film for an acoustic member according to claim 34, which has thermosetting properties.
36. A film for acoustic member according to claim 34 or 35, having a crosslinked structure.
37. The film for an acoustic member according to claim 34 or 35, having a gel fraction of 90% or less.
38. A film for an acoustic member according to claim 34 or 35, which is a silicone film.
39. The film for an acoustic member according to claim 34 or 35, which has the following viscoelastic properties (b) to (d) in a cured state,
(b) Determination of storage modulus E 'at 20℃and frequency 10 Hz' 20 Is 0.1MPa to 500MPa,
(c) Determination of storage modulus E 'at a temperature of 100℃and a frequency of 10 Hz' 100 Is 0.1MPa to 500MPa,
(d) Said E' 100 /E’ 20 Is 0.4～1.0。
40. A film for an acoustic member with a release film, comprising: the film for an acoustic member according to any one of claims 34 to 39, and a release film provided on at least one side of the film for an acoustic member.
41. An acoustic member obtained by curing the acoustic member according to any one of claims 34 to 39 with a film.
42. An acoustic transducer provided with the acoustic member of claim 41.
43. A method for producing a film for an acoustic member according to any one of claims 34 to 39, wherein the method comprises the step of curing at least a part of 1 or more resin layers constituting the film.
44. A method for producing a film for an acoustic member according to claim 43, comprising the step of laminating a cured resin layer and a resin layer having curability.
45. A film, comprising: the resin composition comprises a top-most layer and a bottom-most layer of a cured resin layer, and at least 1 curable intermediate layer disposed between the top-most layer and the bottom-most layer, wherein the top-most layer and the bottom-most layer have a static friction coefficient of 3 or less.
46. The film according to claim 45, wherein the gel fraction is 0% or more and 90% or less.
47. The film of claim 45 or 46, wherein the gel fraction of the top-most layer and the bottom-most layer is 80% or more.
48. The film according to claim 45 or 46, which has the viscoelastic properties of (a) having a storage modulus E' at a measurement temperature of 20 ℃ of 0.1MPa or more and 500MPa or less.
49. The film of claim 45 or 46, which has thermosetting properties.
50. The film of claim 45 or 46 having a crosslinked structure.
51. The film of claim 45 or 46 which is a silicone film.
52. The film of claim 45 or 46, which in the cured state has viscoelastic properties of (b),
(b) Determination of storage modulus E 'at 20℃' 20 Is 0.1MPa or more.
53. The film according to claim 45 or 46, which has the following viscoelastic properties (c) to (e) in a cured state,
(c) Determination of storage modulus E 'at 20℃' 20 Is 0.1MPa to 500MPa,
(d) Determination of storage modulus E 'at 100℃' 100 Is 0.1MPa to 500MPa,
(e) The storage modulus E' 100 With respect to the storage modulus E' 20 Ratio (E ')' 100 /E’ 20 ) Is 0.4 to 1.0.
54. The membrane of claim 45 or 46 which is a membrane for an acoustic member.
55. The film according to claim 45 or 46, which is a film for a vibration plate.
56. A film with a release film, comprising: the film according to any one of claims 45 to 55, and a release film provided on at least one side of the film.
57. An acoustic member obtained by curing the film according to any one of claims 45 to 55.
58. A vibration plate obtained by curing the film according to any one of claims 45 to 55.
59. An acoustic transducer provided with the acoustic member of claim 57.
60. An acoustic transducer comprising the diaphragm of claim 58.
61. The method for producing a film according to any one of claims 45 to 55, comprising the step of laminating an uncured or semi-cured intermediate layer between the cured outermost layer and the cured innermost layer.
62. A method for producing an acoustic member, wherein the film for an acoustic member according to any one of claims 1 to 9, the silicone film according to any one of claims 17 to 24, the film for an acoustic member according to any one of claims 34 to 39, or the film according to any one of claims 45 to 55 is shaped by using a mold.
63. A method of manufacturing an acoustic member according to claim 62, comprising the step of heating the film before disposing the film in the mold.
64. The method for manufacturing an acoustic member according to claim 62 or 63, wherein the heating temperature at the time of shaping is 180 ℃ or higher and 260 ℃ or lower.
65. The method of manufacturing an acoustic member according to claim 62 or 63, wherein the shaping time is 1 second or more and 5 minutes or less.
66. The method for manufacturing an acoustic member according to claim 62 or 63, wherein the shaping is performed by any one of press forming, vacuum forming, and pressure forming.
67. A method for producing an acoustic member, wherein the release film is peeled from the silicone film with a release film according to claim 25, the film for an acoustic member with a release film according to claim 40, or the film with a release film according to claim 56, and the silicone film is placed in a mold to shape.
68. A method of using the film for an acoustic member according to any one of claims 1 to 9, the silicone film according to any one of claims 17 to 24, the film for an acoustic member according to any one of claims 34 to 39, or the film according to any one of claims 45 to 55 for an acoustic member.
69. An acoustic member has a static friction coefficient of at least one face of 3 or less.
70. The acoustic member of claim 69 that includes a silicone membrane.
71. An acoustic member according to claim 69 or 70, having a thickness of 5 μm or more and 500 μm or less.
72. An acoustic member according to claim 69 or 70, having a cross-linked structure.
73. An acoustic member according to claim 69 or 70, having viscoelastic properties of (b) to (d) below,
(b) Determination of storage modulus E 'at 20℃' 20 Is 0.1MPa to 500MPa,
(c) Determination of storage modulus E 'at 100℃' 100 Is 0.1MPa to 500MPa,
(d) The storage modulus E' 100 With respect to the storage modulus E' 20 Ratio (E ')' 100 /E’ 20 ) Is 0.2 to 1.0.
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2021-129390 | 2021-08-05 | ||
| JP2021-129382 | 2021-08-05 | ||
| JP2022-102919 | 2022-06-27 | ||
| JP2022102919A JP2024003639A (en) | 2022-06-27 | 2022-06-27 | Silicone film, molded product, acoustic member, and acoustic transducer |
| PCT/JP2022/030157 WO2023013774A1 (en) | 2021-08-05 | 2022-08-05 | Film for acoustic member |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117795982A true CN117795982A (en) | 2024-03-29 |
Family
ID=89534015
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202280054653.0A Pending CN117795982A (en) | 2021-08-05 | 2022-08-05 | Film for acoustic member |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP2024003639A (en) |
| CN (1) | CN117795982A (en) |
-
2022
- 2022-06-27 JP JP2022102919A patent/JP2024003639A/en active Pending
- 2022-08-05 CN CN202280054653.0A patent/CN117795982A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| JP2024003639A (en) | 2024-01-15 |
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