JP6637919B2 - Method for producing film for speaker diaphragm - Google Patents

Description

  The present invention relates to a method for manufacturing a film for a diaphragm of a speaker having excellent sound quality characteristics and heat resistance.

  2. Description of the Related Art A small speaker called a micro speaker is built in a portable device such as a mobile phone, a portable game device, and a smartphone. In general, a diaphragm for generating sound waves of a speaker called a micro speaker is formed of (1) metal foil, (2) paper, woven fabric, nonwoven fabric made of natural resin, and (3) film made of synthetic resin. It is an important part that determines the sound quality.

  In the case where the diaphragm is a film made of (3) a synthetic resin, a polyolefin resin such as a polyethylene (PE) resin or a polypropylene (PP) resin, a polyethylene terephthalate (PET) resin, a polyethylene naphthalate (PEN) resin, or the like has been used. Films made of polyester resin, polyphenylene sulfide (PPS) resin, polyetherimide (PEI) resin, and the like are used (see Patent Documents 1 and 2).

  By the way, in recent years, loudspeakers have been increasingly improved in function and performance. Therefore, the required characteristics of the speaker diaphragm are becoming more and more severe. The required characteristics of the diaphragm include light weight (low density or specific gravity), moderate rigidity (Young's modulus and elastic modulus), excellent thickness accuracy, loss tangent (both internal loss and , Tan δ) and excellent heat resistance. In addition, it is also excellent in moisture resistance, water resistance, and moldability (press molding, vacuum molding, pressure molding, etc.).

However, when the diaphragm of the speaker is the metal foil of (1), although the heat resistance and the water resistance are excellent, the rigidity is large, so that the minimum resonance frequency (f ₀ ) is high, and the bass reproduction characteristics are insufficient. . In addition, since the important loss tangent (also referred to as internal loss, also referred to as tan δ) of the diaphragm is small, the diaphragm resonates, the acoustic characteristics are disturbed, high performance cannot be expected, and a problem occurs in sound quality. . Furthermore, since the density is large, the vibration propagation speed is reduced, and the reproduction frequency band is narrowed, which causes a problem in acoustic characteristics.

  In the case where the diaphragm of the speaker is made of natural resin paper, woven fabric or non-woven fabric of (2), although the density is low and the weight is low, the rigidity is low, so that a problem arises in reproduction in a high frequency region, and it is important. Since the loss tangent is also small, there is still a problem in sound quality. Further, it becomes difficult to obtain sufficient moisture resistance, water resistance, and heat resistance, and the manufacturing process of the speaker becomes complicated.

  On the other hand, when the diaphragm of the speaker is a film made of a synthetic resin (3), a change in the material of the synthetic resin allows selection of a loss tangent and the like, so that there are few problems and the diaphragm is thin. It is suitable for miniaturization, weight reduction, and mass production, and is most suitable for incorporating small and lightweight portable devices. In view of these points, a diaphragm made of a synthetic resin film is used for a speaker built in a portable device in recent years.

  By the way, recently, due to a change in lifestyle accompanying the enhancement of functions of mobile devices, not a few users want to enjoy television programs, music, games, and the like on mobile devices regardless of time and place. More specifically, a single portable device can be used in public transportation vehicles when commuting, beaches and ski resorts where the temperature changes drastically, recreational facilities during noisy vacations, running when swinging up, down, left and right, etc. Many users want to enjoy TV programs, music, games, etc., and use their time effectively to enrich their lives.

  In order to satisfy the demands of such users, the performance of the speaker should be taken into account, taking into account the special circumstances that the speaker is not built into stationary audio equipment used in a stable environment but is built into portable equipment. It is necessary to improve or increase the output. Specifically, on the premise that the portable device is used for a long time in an unfavorable use environment or the external output is increased and the loud volume is used for a long time, the heat resistance of the speaker diaphragm is further improved, There is a need to improve speaker durability.

  Since the synthetic resin film has insufficient heat resistance, when used as a diaphragm for a speaker, if the external output is increased, the diaphragm is deformed or damaged by high heat generated by high vibration of the voice coil. Causes a problem in durability. Therefore, in recent years, a film made of polyetheretherketone (PEEK) resin has been proposed and implemented as a film for a diaphragm of a speaker (see Patent Document 3).

JP-A-60-139098 JP-A-64-067099 JP-A-58-222699

The film made of polyetheretherketone resin has a glass transition point of 140 ° C. or more and 150 ° C. or less (measuring method: differential scanning calorimetry) and a melting point of 330 ° C. or more and 350 ° C. or less (measuring method: differential scanning calorimetry). ) And excellent heat resistance.
However, it is said that a high-performance, high-output speaker generates heat due to high vibration of the voice coil at the time of output, and the temperature of the diaphragm reaches about 150 ° C. Since the film made of polyetheretherketone resin has a glass transition point of 150 ° C. or lower, when used for a diaphragm, the diaphragm may be deformed or damaged due to high heat accompanying high vibration of the voice coil. .

  The present invention has been made in view of the above, and an object of the present invention is to provide a method of manufacturing a film for a speaker diaphragm, which can ensure heat resistance of 150 ° C. or higher and can improve the durability of the diaphragm. And

  The present inventors have conducted intensive studies to solve the above problems, and as a result, focused on a polyether ketone ketone resin having a very high glass transition point, and a molding material containing this polyether ketone resin has excellent heat resistance. The present invention was completed by producing a film.

That is, in the present invention, in order to solve the above-mentioned problems, a method for producing a film for a diaphragm of a speaker, which forms a film using a resin-containing molding material,
A molding material containing a polyetherketone ketone resin is melt-kneaded, and a film is continuously extruded from a die into a band shape using the molding material, and the extruded film is sandwiched between a pressing roll and a cooling roll. By cooling in, the thickness of the cooled film to 2μm or more and 110μm or less,
The tensile elastic modulus at 23 ° C. of the film after cooling with a 2000N / mm ² or more 4000 N / mm ² or less, a tensile modulus at 0.99 ° C. the film after cooled to 2000N / mm ² or more 4000 N / mm ² or less, It is characterized in that the specific gravity of the film after cooling is 1.2 or more and 1.4 or less, and the loss tangent at 20 ° C. of the film after cooling is 0.010 or more.

It is preferable that the molding material is charged while supplying an inert gas to the extruder, and that the temperature of at least the cooling roll of the pressure-bonding roll and the cooling roll is adjusted to 50 ° C or more and 260 ° C or less.
In addition, when forming fine irregularities on the peripheral surface of the cooling roll and cooling the film by sandwiching the film between the pressure roll and the cooling roll, the fine irregularities of the cooling roll can be transferred to the film to reduce the friction coefficient. it can.

Further, the film after cooling can be laminated and bonded to an elastomer layer having a thickness of 10 μm or more and 100 μm or less, and these can be thermoformed.
Alternatively, the cooled film may be laminated and adhered to at least one of the two surfaces of the elastomer layer via a primer, and these may be thermoformed.
Further, the durometer hardness when the elastomer layer is made of a silicone resin and measured with a durometer type A according to JIS K 6253 can be A10 or more and A90 or less.

  Here, the thickness tolerance of the cooled film in the claims is preferably within a range of an average value ± 10%. The number of pressure rolls and cooling rolls can be increased or decreased as needed. Downstream of the pressure roll, a film winder is installed. Between these pressure rolls and the winder, a slit blade that forms a slit on the side of the film from the viewpoint of easily processing the film. Is disposed, and a tension roll for applying tension to the film can be rotatably supported between the slit blade and the winder.

  The diaphragm film is used exclusively for a speaker, and the speaker is mainly of a direct emission type that directly emits sound into the atmosphere from a diaphragm having a size approximately equal to the wavelength of sound. However, in addition to the direct radiation type, a horn type may be used. The speaker is mainly built in a portable device, and the portable device includes at least a mobile phone, a portable music device, a portable game device, a smartphone, a tablet PC, a notebook personal computer, and the like.

According to the present invention, not a polyetheretherketone resin, but a film extruded from a polyetherketoneketone resin having a higher glass transition temperature than this resin, and the tensile modulus of the cooled film at 23 ° C. is 2000 N / mm. with a ² or more 4000 N / mm ² or less, a tensile modulus at 0.99 ° C. the film after cooled to 2000N / mm ² or more 4000 N / mm ² or less, 1.2 to 1.4 specific gravity of the film after cooling Since the loss tangent at 20 ° C. of the film after cooling is 0.010 or more, heat resistance of 150 ° C. or more can be given to the film. Therefore, even if the film is used for the diaphragm of the speaker, the possibility that the diaphragm is deformed or damaged can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, there exists an effect that the heat resistance of 150 degreeC or more can be ensured, and the durability of the diaphragm of a speaker can be improved.

  According to the second aspect of the present invention, since the inert gas is supplied during the production of the film, it is possible to prevent oxidative deterioration and oxygen crosslinking of the molding material. Further, since the temperature of the cooling roll is at least in the range of 50 ° C. or more and 260 ° C. or less, it is possible to eliminate the possibility that the film being manufactured is stuck to the cooling roll and is broken. In addition, prevention of dew condensation on the cooling roll can be expected.

  According to the third aspect of the present invention, a diaphragm obtained by laminating a film obtained from a molding material containing a polyetherketoneketone resin on an elastomer layer having excellent sound quality characteristics and compression characteristics is manufactured. Even if a portable device is used for a long time in an unfavorable use environment for a long time, and the high power of a speaker or the like generates heat or vibration in a voice coil or the like, the durability and sound quality characteristics of the diaphragm are improved. It becomes possible. Further, since the thickness of the elastomer layer is in the range of 10 μm or more and 100 μm or less, it is possible to reduce the weight and improve the acoustic characteristics.

According to the fourth aspect of the present invention, since a silicone resin is used for the elastomer layer, a diaphragm excellent in heat resistance, weather resistance, flame retardancy, sound quality characteristics, and compression characteristics can be obtained. Further, since the durometer hardness of the silicone resin is in the range of A10 or more and A90 or less, it is possible to prevent the compression set characteristic of the silicone resin from deteriorating, and to prevent the vibration propagation speed of the diaphragm from lowering and adversely affecting sound quality. it can. Furthermore, it lowered the loss tangent, with increasing f ₀ value, it is possible to prevent the performance of the diaphragm is deteriorated.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall explanatory view schematically showing an embodiment of a method for manufacturing a film for a diaphragm of a speaker according to the present invention. It is sectional explanatory drawing which shows typically the diaphragm in embodiment of the manufacturing method of the film for diaphragms of the speaker which concerns on this invention.

Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, a method for manufacturing a film for a diaphragm of a loudspeaker is performed by using a resin-containing molding material 1 as shown in FIG. Is a method of molding a film 2 for use, and a melt extruder 10 is used to melt-knead a molding material 1 containing a polyetherketone ketone resin having excellent heat resistance in a high-temperature region. The thin film 2 is continuously extruded, and the extruded film 2 is sandwiched between a pair of pressure rolls 17 and a cooling roll 18 and cooled, so that the thickness of the cooled film 2 is 2 μm or more. The thickness is set to 110 μm or less.
The polyetherketoneketone resin of the molding material 1 is not particularly limited, but is a resin having a repeating unit represented by the chemical formula (1).

  More specifically, it is a resin having a repeating unit of the chemical formula [Chemical Formula 2] and the chemical formula [Chemical Formula 3].

  The repeating unit of the chemical formula [Chemical formula 2] and the chemical formula [Chemical formula 3] may be any of random repetition, alternate repetition, and block repetition.

  Here, the unit ratio of the chemical formula [Chemical formula 2] and the chemical formula [Chemical formula 3] is preferably in the range of (chemical formula [chemical formula 2] / chemical formula [chemical formula 3]) = (50/50) to (90/10). Preferably, (Chemical formula [Chemical formula 2] / Chemical formula [Chemical formula 3]) = (70/30) to (90/10), more preferably (Chemical formula [Chemical formula 2] / Chemical formula [Chemical formula 3]) = (75 / The range of 25) to (85/15) is good. If the chemical formula [Chemical formula 2] / Chemical formula [Chemical formula 3] is in the range of (75/25) to (85/15), the crystallization rate is high, and the mechanical properties, solvent resistance, and heat resistance are high. This is because it is possible to obtain a film 2 containing a polyether ketone ketone resin excellent in the above.

  When the unit ratio of the chemical formula [Chemical Formula 2] is less than 50, the degree of crystallization and the crystallization rate of the polyetherketoneketone resin are reduced, so that the polyetherketoneketone resin-containing molding material 1 is obtained. This is because the mechanical properties, solvent resistance, and heat resistance of the film 2 are reduced. Conversely, in the case of a polyetherketoneketone resin having a unit ratio exceeding 90, the melting point of the polyetherketoneketone resin and the decomposition temperature of the polyetherketoneketone resin are close to each other. This is because, when the film 2 is formed by melt extrusion of the molding material 1, the polyether ketone ketone resin may be thermally decomposed during the forming.

  The melting point of the polyether ketone ketone resin is usually 300 ° C. to 370 ° C., preferably 330 ° C. to 365 ° C., and more preferably 350 ° C. to 360 ° C. The glass transition point of the polyether ketone ketone resin is from 150 ° C. to 180 ° C., preferably from 155 ° C. to 175 ° C., and more preferably from 160 ° C. to 170 ° C. As a specific example of the polyetherketone ketone resin, a product name: KEPSTAN series manufactured by Arkema Corporation can be mentioned.

  As a method for producing a polyetherketone ketone resin, for example, US Pat. No. 3,516,966, US Pat. No. 3,637,592, US Pat. No. 3,441,538, Japanese Patent Publication No. 4-63900, The production method described in Japanese Patent Publication No. 6-10258 is used. In addition, the polyether ketone ketone resin, a random copolymer with another copolymerizable monomer, an alternating copolymer, a block copolymer, or a modified product is also used as long as the effects of the present invention are not impaired. It is possible.

  Polyether ketone ketone resin-containing molding material 1 includes, in addition to polyether ketone ketone resin, polyimide resin such as polyimide (PI) resin, polyamide imide (PAI) resin, polyether imide (PEI) resin, and polyamide 4T (PA4T). ) Resin, polyamide 6T (PA6T) resin, modified polyamide 6T (modified PA6T) resin, polyamide 9T (PA9T) resin, polyamide 10T (PA10T) resin, polyamide 11T (PA11T) resin, polyamide 6 (PA6) resin, polyamide 66 ( PA66) resin, polyamide resin such as polyamide 46 (PA46) resin, polyester resin such as polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, polyethylene naphthalate (PEN) resin, polyether Polyaryletherketone resin such as ton (PEK) resin, polyetheretherketone (PEEK) resin, polyetheretherketoneketone (PEEKK) resin, polyetherketoneetherketoneketone (PEKEKK) resin, polysulfone (PSU) resin, poly Polyarylene sulfide resins such as ether sulfone (PES) resin, polyphenyl sulfone (PPSU) resin and other polysulfone resins, polyphenylene sulfide (PPS) resin, polyphenylene sulfide ketone resin, polyphenylene sulfide sulfone resin, polyphenylene sulfide ketone sulfone resin; A liquid crystal polymer (LCP), a polycarbonate (PC) resin, a polyarylate (PAR) resin, or the like can be added as needed.

  The molding material 1 contains, in addition to the above resins, an antioxidant, a light stabilizer, an ultraviolet absorber, a plasticizer, a lubricant, a flame retardant, an antistatic agent, a heat resistance improver, and an inorganic compound as long as the properties of the present invention are not impaired. And an organic compound can be selectively added.

  When a film 2 for a diaphragm is manufactured using such a molding material 1 containing a polyether ketone ketone resin, a known manufacturing method such as a melt extrusion molding method, a calendar molding method, or a casting molding method is employed. can do. However, from the viewpoint of improving the thickness accuracy, productivity, and handleability of the film 2 and simplifying the equipment, it is preferable to continuously extrude the thin film by the melt extrusion molding method. Here, the melt extrusion molding method is, as shown in FIG. 1, a molding material 1 is melt-kneaded using a melt extrusion molding machine 10, and a T-die 13 at a tip end of the melt extrusion molding machine 10 is used for a diaphragm. This is a molding method for continuously extruding the film 2.

  The melt-extrusion molding machine 10 includes, for example, a single-screw extruder or a twin-screw extruder, and functions to melt-knead the injected molding material 1. A raw material inlet 11 for the molding material 1 is provided at the upper rear of the melt extrusion molding machine 10. The raw material inlet 11 is provided with helium gas, neon gas, argon gas, krypton gas, nitrogen gas, carbon dioxide gas. An inert gas supply pipe 12 for supplying an inert gas (see an arrow in FIG. 1) as necessary is connected to the molding material 1. Oxidation degradation and oxygen crosslinking are effectively prevented.

  The temperature of the polyetherketone ketone resin at the time of melt-kneading of the melt extrusion molding machine 10 is a temperature at which melt-kneading is possible, and is not particularly limited as long as the polyetherketone-ketone resin does not thermally decompose. And the melting point of the polyether ketone ketone resin or higher and lower than the thermal decomposition temperature. Specifically, the temperature is adjusted to 320 ° C to 450 ° C, preferably 360 ° C to 420 ° C, more preferably 380 ° C to 400 ° C. This is because when the melting point is lower than the melting point of the polyether ketone ketone resin, the molding material 1 containing the polyether ketone ketone resin cannot be melt-extruded. This is because the ketone resin may be severely decomposed.

  The T-die 13 is attached to the distal end of the melt extrusion molding machine 10 via a connecting pipe 14, and functions to continuously extrude the belt-shaped film 2 downward. The temperature at the time of extrusion of the T-die 13 is in the range from the melting point of the polyetheretherketone resin to the thermal decomposition temperature. Specifically, the temperature is adjusted to 320 ° C to 450 ° C, preferably 360 ° C to 420 ° C, more preferably 380 ° C to 400 ° C. This is because if the melting point is lower than the melting point of the polyether ketone ketone resin, the melt extrusion of the molding material 1 becomes difficult, and if it exceeds the thermal decomposition temperature, the polyether ketone ketone resin may be decomposed. Based on reason.

  It is preferable that a gear pump 15 and a filter 16 are respectively mounted on the connection pipe 14 upstream of the T die 13. The gear pump 15 functions to transfer the molding material 1 melt-kneaded by the melt extrusion extruder 10 to the T-die 13 at a constant flow rate and with high precision via the filter 16. The filter 16 separates the gel or the like of the molding material 1 in the molten state, and transfers the molding material 1 in the molten state to the T-die 13.

  The pair of pressure rolls 17 are rotatably supported below the T-die 13 and slidably hold the cooling roll 18. A winding pipe 20 of a winder 19 for winding the film 2 is rotatably installed downstream of the downstream pressure roll 17 of the pair of pressure rolls 17. A slit blade 21 that forms a slit on the side of the film 2 is disposed between the slit blade 21 and the winding tube 20 of the winding machine 19 between the slit tube 21 and the winding tube 20. A required number of rotatable tension rolls 22 for applying tension to the film 2 and smoothly winding the film 2 are supported.

  From the viewpoint of improving the adhesion between the film 2 and the cooling roll 18, at least the natural rubber, isoprene rubber, butadiene rubber, norbornene rubber, acrylonitrile butadiene rubber, nitrile rubber, urethane rubber, silicone A rubber layer such as rubber or fluororubber is formed if necessary, and an inorganic compound such as silica or alumina is selectively added to the rubber layer. Among these, it is preferable to use silicone rubber or fluorine rubber having excellent heat resistance.

  As the pressing roll 17, a metal elastic roll having a metal surface is used as necessary. When this metal elastic roll is used, the film 2 having a surface having excellent smoothness can be formed. Specific examples of the metal elastic roll include, for example, a metal sleeve roll, an air roll (product name manufactured by Dimco), and a UF roll (product name manufactured by Hitachi Zosen Corporation).

  Such a pressure roll 17 is adjusted to a temperature of 260 ° C. or less, preferably 50 ° C. or more and 260 ° C. or less, more preferably 130 ° C. or more and 240 ° C. or less, slides on the film 2 and presses it against the cooling roll 18. . The reason why the temperature of the pressure bonding roll 17 is in the range is that if the temperature of the pressure bonding roll 17 exceeds 260 ° C., the film 2 being manufactured is stuck to the pressure bonding roll 17 and the film 2 may be broken. Conversely, if the temperature is lower than 50 ° C., the pressure-bonding roll 17 is condensed, which is not preferable. Examples of the method for adjusting the temperature and cooling of the pressing roll 17 include a method using a heat medium such as air, water, and oil, an electric heater, and a dielectric heating roll.

  The cooling roll 18 is made of, for example, a metal roll having a diameter larger than that of the pressing roll 17. The cooling roll 18 is rotatably supported below the T-die 13 and sandwiches the extruded film 2 between the cooling roll 18 and the pressing roll 17. It functions to control the thickness of the film 2 within a predetermined range while cooling the film 2 together with the film 17. The cooling roll 18 is adjusted to a temperature of 260 ° C. or less, preferably 50 ° C. or more and 260 ° C. or less, more preferably 130 ° C. or more and 240 ° C. or less, like the pressure roll 17, and slides on the film 2.

  The reason why the temperature of the cooling roll 18 is adjusted to 50 ° C. or more and 260 ° C. or less is that when the temperature of the cooling roll 18 exceeds 260 ° C., the film 2 being manufactured may stick to the cooling roll 18 and break. Based on the reason that there is. On the other hand, when the temperature is lower than 50 ° C., the cooling roll 18 is condensed, which is not preferable. The method of adjusting the temperature of the cooling roll 18 and cooling may be a method using a heat medium such as air, water, or oil, or an electric heater or dielectric heating.

  In the above, when manufacturing the film 2 for a diaphragm, as shown in FIG. 1, a molding material 1 containing a polyetherketone ketone resin is inserted into a raw material inlet 11 of a melt extrusion molding machine 10 by an arrow in FIG. While supplying the inert gas shown, the melt extruder 10 melts and kneads the molding material 1 in a heated and pressurized state, and continuously extrudes the thin film 2 from the T die 13 into a strip shape.

  At this time, the water content of the molding material 1 containing the polyether ketone ketone resin before the melt-kneading is adjusted to 2000 ppm or less, preferably 1000 ppm or less, more preferably 100 ppm or more and 1000 ppm or less. This is because if the water content of the polyetherketoneketone resin before melt-kneading exceeds 2000 ppm, the polyetherketoneketone resin may foam.

  After extruding the belt-shaped film 2, the film 2 is sequentially wound around a pair of pressure rolls 17, a cooling roll 18, a tension roll 22, and a winding tube 20 of a winding machine 19, and the film 2 is cooled by the cooling roll 18. By cutting both sides of each 2 with slit blades 21 and winding them sequentially on a winding tube 20, a film 2 for a diaphragm made of polyetherketoneketone resin can be manufactured. During the production of the film, fine irregularities are formed on the surface of the film 2 as long as the effects of the present invention are not lost, and the coefficient of friction on the surface of the film 2 can be reduced.

  As a method for forming fine irregularities, for example, (1) a molding material 1 containing a polyetherketone ketone resin is melt-kneaded by a melt extrusion molding machine 10, and the melt-kneaded molding material 1 is subjected to fine irregularities from a T-die 13. A method in which fine irregularities are simultaneously transferred and formed at the time of forming the film 2 by discharging and closely adhering onto the cooling roll 18 having the peripheral surface. (2) The cooling roll 18 having fine irregularities on the peripheral surface after the film 2 is manufactured. There is a method of forming fine irregularities by closely contacting the top. Either method can be adopted, but from the viewpoint of simplification of equipment, management of the thickness accuracy of the film 2, and maintenance of the appearance of the film 2, the method (1) is most suitable.

  The thickness of the film 2 made of the polyetherketoneketone resin after cooling is preferably in the range of 2 μm to 110 μm, preferably 3 μm to 105 μm, more preferably 5 μm to 100 μm. This is because if the thickness of the film 2 is less than 2 μm, the mechanical strength of the film 2 is significantly reduced, and it is difficult to form the film 2. Conversely, when the thickness of the film 2 exceeds 110 μm, the diaphragm becomes thick and large, and the size of the speaker becomes large, which makes the film unsuitable for a speaker for a portable device. The thickness of the film 2 can be measured by various contact-type thickness gauges.

  The thickness tolerance of the film 2 is preferably within a range of an average value ± 10%, and more preferably within a range of an average value ± 5%. This is because if the thickness tolerance of the film 2 is out of the range of the average value ± 10%, the sound quality varies. The thickness tolerance of the film 2 can be obtained by a predetermined formula.

The mechanical properties of the film 2 made of polyetherketoneketone resin after cooling can be evaluated by the tensile modulus at 23 ° C. Tensile modulus at 23 ° C. of polyether ketone ketone resin film 2 after cooling, 2000N / mm ² or more 4000 N / mm ² or less, preferably in the range of 2300N / mm ² or more 3950N / mm ² or less, more preferably The optimum range is 2400 N / mm ² or more and 3900 N / mm ² or less. This is based on the reason that when the tensile elastic modulus of the film 2 is less than 2000 N / mm ² , the high-frequency resonance frequency (f _H ) of the film-made diaphragm is low, and the high-frequency sound reproduction becomes insufficient. On the other hand, when it exceeds 4000 N / mm ² , it is based on the reason that the lowest resonance frequency (f ₀ ) of the diaphragm obtained from the film 2 is high and bass reproduction becomes insufficient.

  The heat resistance of the film 2 made of polyetheretherketone resin after cooling can be evaluated by the glass transition point and the tensile modulus at 150 ° C. The glass transition point of the film 2 made of polyetherketoneketone resin after cooling is 150 ° C. or higher, preferably 155 ° C. or higher, and more preferably 161 ° C. or higher. This is because, when the glass transition point of the film 2 is lower than 150 ° C., the heat resistance of the film 2 is insufficient, so that when the diaphragm obtained from the film 2 is used for a speaker, the high vibration of the voice coil causes This is because the generated high heat causes a problem in durability such as deformation or breakage of the diaphragm obtained from the film 2.

Tensile modulus at 0.99 ° C. polyether ketone ketone resin film 2 after cooling, 2000N / mm ² or more 4000 N / mm ² or less, preferably in the range of 2100 N / mm ² or more 3700N / mm ² or less, more preferably 2200N / mm ² or more 3650N / mm ² or less in the range is optimal. This is because when the tensile modulus of the film 2 at 150 ° C. is less than 2000 N / mm ² , the heat resistance of the film 2 is insufficient, so that when the diaphragm obtained from the film 2 is used for a speaker, This is because high heat accompanying the high vibration of the coil causes a problem in durability, such as deformation or breakage of the diaphragm obtained from the film 2. In addition, the high-band resonance frequency (f _H ) of the film diaphragm is low, and high-frequency sound reproduction becomes insufficient. On the other hand, if it exceeds 4000 N / mm ² , the lowest resonance frequency (f ₀ ) of the diaphragm obtained from the film 2 is high and bass reproduction becomes insufficient.

  The acoustic characteristics of the film 2 made of polyetherketoneketone resin after cooling can be evaluated by the specific gravity of the film 2 at 23 ° C. and the loss tangent of the film 2 at 20 ° C. The specific gravity of the polyetheretherketone resin film 2 after cooling is preferably 1.2 or more and 1.4 or less, preferably 1.22 or more and 1.35 or less, more preferably 1.25 or more and 1.31 or less. is there. This is because, in this range, the density is small, so that a reduction in weight can be expected, and the vibration propagation speed increases and the reproduction frequency band is widened, so that good sound quality acoustic characteristics can be obtained.

  The loss tangent at 20 ° C. of the film 2 made of a polyetherketoneketone resin after cooling is 0.010 or more, preferably 0.011 or more, and more preferably 0.013 or more. This is because when the loss tangent is less than 0.010, the sound quality characteristics vary due to the occurrence of resonance. The upper limit of the loss tangent is not particularly limited, but is preferably 0.4 or less.

  Although the manufactured film 2 can be used as a diaphragm as it is, from the viewpoint of obtaining excellent sound quality characteristics, compression characteristics, and loss tangent, it is used as a part of the laminated intermediate 3 shown in FIG. Is preferably formed into a diaphragm. As shown in FIG. 2, the laminated intermediate 3 includes an elastomer layer 4 having a thickness of 10 μm or more and 100 μm or less, and a pair of upper and lower films 2 that are laminated and adhered to the front and back surfaces of the elastomer layer 4 via the primer 5. Prepared for multi-layer structure, mainly used for built-in portable equipment.

  Examples of the elastomer used for the elastomer layer 4 include a silicone resin, a urethane resin, an acrylic resin, a fluororesin, a polyester resin, a polyamide resin, and a hydrocarbon resin. Among these elastomers, silicone resins are preferred because they are excellent in heat resistance, weather resistance, flame retardancy, sound quality characteristics, compression characteristics and the like.

  The silicone resin used for the elastomer layer 4 is composed of a silicone resin composition, and the silicone resin composition is preferably a heat-curable silicone resin from the viewpoint of suitability for production of an intermediate and storage suitability after production. Examples of the heat-curable silicone resin include an addition-curable millable silicone resin and an addition-curable liquid silicone resin. The addition-curable millable silicone resin is usually composed of an organopolysiloxane, a silica-based filler, and a curing agent (a curing agent obtained by combining a known platinum-based catalyst with an organohydrogenpolysiloxane, and an organic oxide). ) And various additives such as silica fine powder.

In contrast, addition-curable liquid silicone resins contain an organopolysiloxane containing at least two alkenyl groups bonded to silicon atoms in one molecule, and an organopolysiloxane containing at least two hydrogen atoms bonded to silicon atoms in one molecule. And inorganic fillers having an average particle diameter of 1 μm or more and 30 μm or less and a bulk density of 0.1 g / cm ³ or more and 0.5 g / cm ³ or less (diatomaceous earth, pearlite, pulverized foamed pearlite) , Mica, calcium carbonate, glass flakes, hollow fillers, etc.) and addition reaction catalysts (platinum black, platinic chloride, chloroplatinic acid, reactants of chloroplatinic acid and monohydric alcohol, chloroplatinic acid and olefins) With platinum complex, platinum bis acetoacetate, palladium-based catalyst, rhodium-based catalyst, etc.) It is.

  The silicone resin composition to be used as the silicone resin is prepared by using a kneader such as a calender roll such as a two-roller or a three-roller, a roll mill, a Banbury mixer, a dough mixer (kneader) or the like, and optionally various additives. Are kneaded at room temperature or under heating for several minutes to several hours, preferably 5 minutes to 1 hour, until they are uniformly mixed. The normal temperature here refers to a temperature range of about 0 to 50 ° C.

  The thickness of the elastomer layer 4 is optimally 10 μm or more and 100 μm or less, preferably 20 μm or more and 80 μm or less, more preferably 50 μm or more and 75 μm or less, from the viewpoint of obtaining excellent acoustic characteristics by weight reduction. The thickness here refers to the thickness after curing when a silicone resin is used for the elastomer layer 4.

  The durometer hardness of the silicone resin when a silicone resin is used for the elastomer layer 4 is A10 or more and A90 or less, preferably A20 or more and A70 or less, more preferably A20 or more and A70 or less, when measured with a durometer type A in accordance with JIS K6253. The range from A20 to A50 is optimal. This is because when the durometer hardness is less than A10, the compression set characteristic of the silicone resin layer is deteriorated, and the vibration propagation speed of the diaphragm is reduced, resulting in a problem in sound quality. On the other hand, if the durometer hardness exceeds A90, the loss tangent becomes small, and the performance of the diaphragm is deteriorated.

  The primer 5 is interposed between the elastomer layer 4 and the film 2 made of polyetherketoneketone resin, and functions to firmly adhere them. The primer 5 is not particularly limited as long as it can bond the silicone resin and the film 2 made of polyether ketone ketone resin. Examples of the primer 5 include alkyd resins and alkyds such as phenol-modified and silicone-modified. Modified resins, oil-free alkyd resins, acrylic resins, silicone resins, epoxy resins, fluororesins, phenolic resins, silane coupling agents, titanate coupling agents, aluminum coupling agents, and mixtures thereof. Examples of the crosslinking agent for curing and / or crosslinking these resins include isocyanate compounds, melamine compounds, epoxy compounds, peroxides, phenol compounds, hydrogen siloxane compounds, and silane compounds.

  The primer 5 is used in a state of a mixture comprising the above compound and an organic solvent. As the organic solvent, a solvent which is easy to volatilize is preferable. For example, alcohol solvents such as methanol, ethanol or isopropanol, aromatic hydrocarbon solvents such as xylene or toluene, n-hexane, cyclohexane, methylcyclohexane or dimethylcyclohexane And ketone solvents such as acetone and methyl ethyl ketone, and ester solvents such as ethyl acetate and butyl acetate. These organic solvents may be used alone or in combination of two or more. The amount of the organic solvent to be added is appropriately adjusted to an appropriate concentration according to the method of applying the primer 5.

  The primer 5 is applied to any one of the opposing surfaces of the silicone resin and the film 2 made of polyetherketoneketone resin by, for example, a spraying method, a brush coating method, a gravure coating method, a die coating method, a bar coater (Meyer bar) method, an impregnation coating. It is applied thinly by a known method such as a method, and after evaporating the organic solvent, a thin film layer is formed.

  The primer 5 of the thin film layer has a thickness of 0.1 μm or more and 5 μm or less, preferably 1 μm or more and 2 μm or less. This is because, when the thickness of the primer 5 is less than 0.1 μm, the adhesion between the elastomer layer 4 and the film 2 is insufficient, and there is a possibility that the primer 5 may be peeled off during molding into a diaphragm or during use. Because. On the other hand, if the thickness of the primer 5 exceeds 5 μm, the secondary formability to the diaphragm or the acoustic characteristics may be adversely affected.

  When it is desired to improve and improve the wettability of the primer 5 to the elastomer layer 4 and the film 2, the surfaces of the elastomer layer 4 and the film 2 are treated by various surface treatment methods as long as the properties of the present invention are not impaired. Just do it. Examples of various surface treatment methods include known methods such as corona irradiation treatment, ultraviolet irradiation treatment, plasma irradiation treatment, flame treatment, flame treatment, and itro treatment.

  The thickness of the pair of films 2 may be different or equal on both surfaces of the elastomer layer 4, but is preferably equal. This is because when the thickness of the pair of films 2 is different, the heat shrinkage of the films 2 is different, so that the diaphragm may be curled after molding.

  As a method for producing such a laminated intermediate 3, first, an elastomer used for the elastomer layer 4 is formed into a sheet shape, and this elastomer and a pair of films 2 already formed are interposed via a primer 5. Laminate. As a method for forming the elastomer into a sheet, a known production method such as a normal temperature extrusion molding method, a melt extrusion molding method, a calendar molding method, or a casting molding method can be employed. If there is a problem in handling properties such as low mechanical properties or severe stickiness of the elastomer used for the elastomer layer 4, the elastomer is placed on a non-stretchable base sheet such as a polyethylene terephthalate (PET) resin sheet. May be divided into a predetermined thickness. The ordinary temperature here refers to a temperature range of 0 to 50 ° C.

  When the elastomer of the elastomer layer 4 is, for example, a silicone resin, first, a silicone resin composition is prepared and kneaded by using two or three calender rolls, and the kneaded silicone resin composition is treated with a polyethylene terephthalate (PET) resin sheet or the like. A non-stretchable base sheet is separated by a calender roll into a sheet having a predetermined thickness, and a film 2 of polyetherketoneketone resin which has been already molded is primer-coated on the exposed surface of the silicone resin composition. Laminate through 5.

  Next, the base sheet is placed on the film 2 side, the base sheet is peeled off to expose the adhesive surface of the silicone resin composition, and another film made of polyetherketone ketone resin is exposed on the exposed surface of the silicone resin composition. By laminating 2 via the primer 5, the laminated intermediate 3 can be produced.

  After the laminated intermediate 3 is manufactured, if the laminated intermediate 3 is formed into a diaphragm by press forming using a mold, vacuum forming, or thermoforming such as pressure forming, vibration of a small speaker without wrinkles can be obtained. Boards can be manufactured. At this time, when a silicone resin is used for the elastomer layer 4, the silicone resin is cured at the same time as the formation of the diaphragm, and if it is adjusted to a predetermined size and shape, a small speaker diaphragm without wrinkles is manufactured. can do.

  The thermoforming temperature of the laminated intermediate 3 is equal to or higher than the glass transition point and lower than the melting point of the polyetherketoneketone resin film 2 from the viewpoint of moldability into a diaphragm. Specifically, the temperature is from 160 ° C to 300 ° C, preferably from 180 ° C to 250 ° C. This is because when the thermoforming temperature is lower than the glass transition point temperature of the film 2, it is difficult to form the laminated intermediate 3 into a diaphragm, and when the thermoforming temperature is higher than the melting point of the film 2, This is because the film 2 is melted to lower the shape, or the elastomer used for the elastomer layer 4 is thermally decomposed or denatured.

According to the above, melt extruded by polyether ketone ketone resin excellent in heat resistance of the film 2 of the high temperature region, and a tensile modulus at 23 ° C. After cooling of the film 2 2000N / mm ² or more 4000 N / mm ² or less as well as, a tensile modulus at 0.99 ° C. of the film 2 after cooled to 2000N / mm ² or more 4000 N / mm ² or less, the specific gravity of the film 2 after cooling is 1.2 to 1.4, the film after cooling Since the loss tangent of No. 2 at 20 ° C. is 0.010 or more, heat resistance of 150 ° C. or more can be obtained. Therefore, even if the diaphragm is used as a diaphragm of a speaker, it is possible to effectively eliminate the possibility that the diaphragm is deformed or damaged due to high heat caused by high vibration of the voice coil.

  Further, a pair of polyetherketone-ketone resin films 2 are laminated on the elastomer layer 4 having excellent sound quality characteristics, compression characteristics, and the like to manufacture a diaphragm having both of these characteristics. The durability and acoustic characteristics of the diaphragm can be improved even if the diaphragm is used for a long time and the external output increases with the enhancement of the function and the output of the speaker, and the voice coil generates heat and vibrates.

  In particular, a silicone resin having excellent heat resistance, weather resistance, flame retardancy, sound quality characteristics, compression characteristics, and the like is used for the elastomer layer 4, and a pair of polyetherketone ketone resin films 2 are laminated on the silicone resin. If a diaphragm with characteristics is manufactured, even if a portable device is used for an unfavorable use environment for a long time, the external output increases with the high performance and high output of the speaker, and heat and vibration are generated in the voice coil. Even if this occurs, the heat resistance and acoustic characteristics of the diaphragm can be significantly improved.

Further, by combining the elastomer layer 4 having excellent loss tangent and the film 2 made of polyetherketone ketone resin, the loss tangent of the diaphragm is improved, so that the acoustic characteristics can be improved. In particular, large loss tangent, if compounding a silicone resin and a polyether ketone ketone resin film 2 which is excellent in preventing effect an increase of f ₀ value, the heat resistance and the loss tangent of the vibration plate, bass reproduction Since the characteristics are significantly improved, extremely excellent durability and acoustic characteristics can be obtained.

  In the above-described embodiment, the diaphragm has a multilayer structure including the elastomer layer 4 and the films 2 laminated and bonded to both surfaces of the elastomer layer 4 with the primer 5 interposed therebetween, but the invention is not limited to this. Not something. For example, only the film 2 may be used, and the elastomer layer 4 may be omitted. Further, on the surface of the film 2, various antistatic agents, silicone resins, acrylic resins, various elastomers such as urethane resins are applied as long as the effects of the present invention are not lost, or aluminum, tin, nickel, copper, etc. Various metals may be deposited.

Hereinafter, examples of the method for manufacturing a film for a diaphragm of a speaker according to the present invention will be described together with comparative examples.
[Example 1]
First, a commercially available polyetherketoneketone resin (product name: KEPSTAN 8002, manufactured by Arkema Co., Ltd.) was prepared as a molding material, and the polyetherketoneketone resin was dried in a hot-air dryer heated to 160.degree. C. for 12 hours, and dried. After confirming that the water content of the material was 300 ppm or less, the dried polyetheretherketone resin was set in a φ40 mm single screw extruder equipped with a 400 mm wide T-die, melt-kneaded, and melt-kneaded. The polyether ketone ketone resin was continuously extruded from a T-die of a single screw extruder to extrude a film made of a polyether ketone ketone resin as a diaphragm film into a belt shape.

  At this time, the water content of the polyether ketone ketone resin was measured by Karl Fischer titration using a trace moisture measuring device (product name: CA-100, manufactured by Mitsubishi Chemical Corporation). The single-screw extruder was L / D = 32, compression ratio: 2.5, and screw: full flight screw type. The temperature of the single-screw extruder was adjusted to 380 to 400 ° C, the temperature of the T-die was adjusted to 400 ° C, and the temperature of the connecting pipe connecting the single-screw extruder and the T-die was adjusted to 400 ° C.

  When charging the polyether ketone ketone resin into the single screw extruder, 18 L / min of nitrogen gas was supplied. The temperature of the molten polyetherketoneketone resin was 396 ° C. when the resin temperature at the inlet of the T-die was measured.

  After extrusion-molding the film made of polyetherketoneketone resin, both sides of the continuous film made of polyetherketoneketone resin are cut with a slit blade and sequentially wound around a winding tube of a winder, and the length is 50 m. A diaphragm film made of polyether ketone ketone resin having a width of 300 mm was manufactured. At this time, the film is sequentially wound around a pair of pressure-bonding rolls made of silicone rubber, a metal roll which is a 210 ° C. cooling roll having irregularities on the peripheral surface, and a 3-inch winding pipe located downstream of these. , And held between a pressure roll and a metal roll.

  When a film made of polyetherketoneketone resin, which is a film for a diaphragm, is obtained, the film thickness, film thickness tolerance, mechanical properties, heat resistance properties, and acoustic properties of this film are evaluated, and the results are described in Table 1. did. The mechanical properties are evaluated by the tensile modulus of the film at 23 ° C, the heat resistance is evaluated by the glass transition point of the film and the tensile modulus at 150 ° C, and the acoustic properties are evaluated by the specific gravity of the film at 23 ° C and the loss tangent of the film at 20 ° C. did.

-Film thickness of the film For the thickness of the film having a film thickness of 2 μm or more and 10 μm or less, use a contact-type thickness gauge [product made by Marh, product name: Millimar 1240 compact amplifier equipped with a millimar inductive probe 1301]. Measured. On the other hand, the thickness of the film having a film thickness of more than 10 μm to 110 μm or less was measured using a micrometer [Mitutoyo Co., Ltd. product name: coolant proof micrometer code MDC-25PJ].

  At the time of measurement, the thickness at a predetermined position where the extrusion direction of the film and the width direction (the direction perpendicular to the extrusion direction) intersect was measured at 20 points, and the average value was defined as the film thickness. The measurement points in the extrusion direction were 100 mm, 200 mm, 300 mm, and 400 mm from the leading end of the film. On the other hand, the measurement points in the width direction were 50 mm from the left end of the film, and then 100 mm, 150 mm, 200 mm, and 250 mm at 50 mm intervals.

-Film thickness tolerance The film thickness tolerance was calculated from the following formula.
Film thickness tolerance [%] = {(MAX or MIN) − (AVE)} / (AVE) × 100
Here, MAX: maximum value of film thickness
MIN: minimum value of film thickness
AVE: Average value of film thickness The case where the obtained film thickness tolerance is within ± 5% is A, the case where it is within ± 5-10% is B, and the case where it exceeds ± 10% is NG.

-Tensile modulus at 23 ° C of the film The tensile modulus at 23 ° C of the film was measured in the extrusion direction and the width direction (perpendicular to the extrusion direction) of the film. As a test piece for measurement, JIS K71603 type was used. The tensile modulus was measured in accordance with JIS K7127 under the conditions of a tensile speed of 50 mm / min and a temperature of 23 ° C.

-Glass transition point of film The glass transition point of the film is determined by using a differential scanning calorimeter (manufactured by SII Nanotechnology Co., Ltd .: product name high-sensitivity differential scanning calorimeter X-DSC7000) in accordance with JIS K7121 according to JIS K7121. It was determined from a differential scanning calorimetry curve when the temperature was raised at 10 ° C./min.

-Tensile modulus at 150 ° C of the film The tensile modulus at 150 ° C of the film was measured in the extrusion direction and the width direction (perpendicular to the extrusion direction) of the film. As a test piece for measurement, JIS K71603 type was used. Specifically, a test piece was cut out from the film in the form of JIS K71603 type 3, and the test piece was attached to a tensile tester equipped with a thermostatic chamber heated at 150 ° C. in advance, and measured at a tensile speed of 50 mm / min in accordance with JIS K7127. . The measurement was performed after the test piece was attached to the knob of the tensile tester in the thermostat, the door of the thermostat was closed, the temperature of the thermostat reached 150 ± 2 ° C., and the test piece was left for 3 minutes.

-Specific gravity of the film The specific gravity of the film at 23 ° C was measured at a temperature of 23 ° C in accordance with the measurement method of JIS K7112 (Method A).
-Loss tangent of the film The loss tangent of the film was measured in the film extrusion direction and the width direction (perpendicular to the extrusion direction). Specifically, when measuring the loss tangent in the extrusion direction of the film, cut out to a size of 60 mm in the extrusion direction × 60 mm in the extrusion direction when measuring the loss tangent in the extrusion direction of 60 mm × width direction and 6 mm in the width direction. Measured.

  In the measurement of the loss tangent, the frequency was 1 Hz, the strain was 0.1%, and the heating rate was 3 in a tensile mode using a viscoelastic spectrometer (product name: RSA-G2 manufactured by TS Instruments Japan). C./min., Measurement temperature range -60 to 380.degree. C., measurement was performed under the conditions of 21 mm between checks, and the loss tangent at 20.degree.

[Example 2]
In the case of Example 1, the molding material was continuously extruded from the T-die of the single-screw extruder to extrude a 100 μm-thick polyetherketone-ketone resin film. In the case of Example 2, And a film having a thickness of 25.3 μm was extruded. The other parts were the same as in Example 1.
When a film was obtained, the film thickness, film thickness tolerance, mechanical properties, heat resistance properties, and acoustic properties of this film were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[Example 3]
In the case of Example 1, the molding material was continuously extruded from the T-die of the single-screw extruder to extrude a film having a thickness of 100 μm. The film was extruded. The other parts were the same as in Example 1.
When a film was obtained, the film thickness, film thickness tolerance, mechanical properties, heat resistance properties, and acoustic properties of this film were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[Example 4]
In the case of Example 1, the molding material was continuously extruded from the T-die of the single-screw extruder to extrude a 100 μm-thick film made of polyetherketoneketone resin. In the case of Example 4, And a 5.8 μm thick film was extruded. The other parts were the same as in Example 1.
When a film was obtained, the film thickness, film thickness tolerance, mechanical properties, heat resistance properties, and acoustic properties of this film were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[Example 5]
First, a commercially available polyetherketone ketone resin (manufactured by Arkema Co., Ltd., product name: KEPSTAN 7002) was dried at 150 ° C. for 12 hours using the same heating dryer as in Example 1. When the moisture content of the dried molding material was 300 ppm or less. After confirming that there was, a strip-shaped film made of polyetherketone resin was extruded from the dried polyetherketoneketone resin by using the same single-screw extruder and T-die as in Example 1. .

  At this time, the water content of the polyether ketone ketone resin was measured by the same method as in Example 1. When the polyether ketone ketone resin was charged into the single screw extruder, a nitrogen gas of 18 L / min was supplied. The temperature of the single-screw extruder was adjusted to 360 to 380 ° C, the temperature of the T-die was adjusted to 380 ° C, and the temperature of the connecting pipe connecting the single-screw extruder and the T-die was adjusted to 380 ° C. The temperature of the molten polyether ketone ketone resin was 377 ° C. when the resin temperature at the inlet of the T-die was measured.

  After extrusion-molding a film made of polyetherketoneketone resin, both sides of the film made of polyetherketoneketone resin are cut with slit blades and sequentially wound around a winding tube of a winder, and are 50 m long and 300 mm wide. The diaphragm film made of polyetherketoneketone resin was manufactured. At this time, the film made of polyetherketoneketone resin is composed of a pair of pressure-bonded rolls made of silicone rubber, a metal roll which is a cooling roll at 160 ° C. having irregularities on the peripheral surface, and a 3-inch roll located downstream of these rolls. The tube was wound around the take-up tube in sequence and held between a pressure roll and a metal roll.

  When a film was obtained, the film thickness, film thickness tolerance, mechanical properties, heat resistance properties, and acoustic properties of this film were evaluated in the same manner as in Example 1, and the results are shown in Table 2.

[Example 6]
First, a commercially available polyetherketone ketone resin (manufactured by Arkema, product name: KEPSTAN 6002) was dried at 130 ° C. for 12 hours using the same heating drier as in Example 1, and when the moisture content of the dried molding material was 300 ppm or less. After confirming that there was, a strip-shaped film made of polyetherketone ketone resin was extruded by using the same single-screw extruder and T-die as in Example 1. did.

  At this time, the water content of the polyether ketone ketone resin was measured in the same manner as in Example 1. When the polyether ketone ketone resin was charged into the single screw extruder, a nitrogen gas of 18 L / min was supplied. The temperature of the single-screw extruder was adjusted to 330 to 370 ° C, the temperature of the T-die was adjusted to 370 ° C, and the temperature of the connecting pipe connecting the single-screw extruder and the T-die was adjusted to 370 ° C. The temperature of the molten polyetherketone ketone resin was 367 ° C. as measured by measuring the resin temperature at the entrance of the T-die.

  After extrusion-molding a film made of polyetherketoneketone resin, both sides of the film made of polyetherketoneketone resin are cut with slit blades and sequentially wound around a winding tube of a winder, and are 50 m long and 300 mm wide. The diaphragm film made of polyetherketoneketone resin was manufactured. At this time, the film made of polyetherketoneketone resin is composed of a pair of pressure rolls made of silicone rubber, a metal roll which is a cooling roll at 130 ° C. having irregularities on its peripheral surface, and a 3-inch roll located downstream of these. The tube was wound around the take-up tube in sequence and held between a pressure roll and a metal roll.

  When a film was obtained, the film thickness, film thickness tolerance, mechanical properties, heat resistance properties, and acoustic properties of this film were evaluated in the same manner as in Example 1, and the results are shown in Table 2.

[Comparative Example 1]
First, a commercially available polyetheretherketone resin [product name: KetaSpire PEEK KT-851NL SP (manufactured by Solvay Specialty Polymers) (hereinafter abbreviated as “KT-851NL SP”)] was heated and dried in the same manner as in Example 1. After drying at 160 ° C. for 12 hours and confirming that the moisture content of the dried molding material is 300 ppm or less, the dried polyetheretherketone resin was subjected to the same single-screw extruder and T-die as in Example 1. By using, a belt-shaped film made of polyetheretherketone resin was extruded.

  The single screw extruder was L / D = 32, compression ratio: 2.5, screw: full flight screw type. The temperature of the single-screw extruder was adjusted to 380 to 400 ° C, the temperature of the T-die was adjusted to 400 ° C, and the temperature of the connecting pipe connecting the single-screw extruder and the T-die was adjusted to 400 ° C. The water content of the polyetheretherketone resin was measured in the same manner as in Example 1. Regarding the temperature of the melted polyetheretherketone resin, the resin temperature at the entrance of the T-die was measured, and it was 395 ° C.

  After extruding a polyetheretherketone resin film, cut both sides of the continuous film with a slit blade and wind them sequentially on a winding tube of a winder, made of polyetheretherketone resin having a length of 50 m and a width of 300 mm. Was manufactured. At this time, the film is sequentially wound around a pair of pressure-bonding rolls made of silicone rubber, a metal roll which is a 200 ° C. cooling roll having irregularities on the peripheral surface, and a 3-inch winding pipe located downstream of these. , And held between a pressure roll and a metal roll.

  When a film made of polyetheretherketone resin, which is a film for a diaphragm, is obtained, the film thickness, film thickness tolerance, heat resistance, and acoustic characteristics of this polyetheretherketone resin film are measured in the same manner as in Example 1. And the results are shown in Table 3.

[Comparative Example 2]
By changing the polyetheretherketone resin used in Comparative Example 1 to Vestakeep 3300G (product name manufactured by Daicel Evonik Co.) and using the same single-screw extruder and T-die as in Example 1, a belt-shaped A film made of polyetheretherketone resin was extruded.

The temperatures of the single-screw extruder, the T-die, and the connecting pipe connecting the single-screw extruder and the T-die were the same as in Comparative Example 1. The temperature of the molten polyetheretherketone resin was 397 ° C. when the resin temperature at the inlet of the T-die was measured. The temperature of the metal roll as the cooling roll was set to 200 ° C., which is the same as in Comparative Example 1.
When a film made of a polyetheretherketone resin, which is a film for a diaphragm, is obtained, the film thickness, film thickness tolerance, heat resistance, and acoustic characteristics of this polyetheretherketone resin film are measured in the same manner as in Example 1. The results were evaluated and the results are shown in Table 3.

[Comparative Example 3]
By changing the polyetheretherketone resin used in Comparative Example 1 to Victrex Peak 381G (manufactured by Victrex, product name) and using the same single-screw extruder and T-die as in Example 1, A polyetheretherketone resin film was extruded.

The temperatures of the single-screw extruder, the T-die, and the connecting pipe connecting the single-screw extruder and the T-die were the same as in Comparative Example 1. The temperature of the molten polyetheretherketone resin was 396 ° C. when the resin temperature at the inlet of the T-die was measured. The temperature of the metal roll as the cooling roll was changed to 130 ° C.
When a film made of polyetheretherketone resin, which is a film for a diaphragm, was obtained, the film thickness, film thickness tolerance, heat resistance, and acoustic characteristics of this film were evaluated in the same manner as in Example 1, and the results were tabulated. No. 3.

[Evaluation]
Film made polyetherketoneketone resin in each example, the glass transition point of 160 ° C. or more, a tensile elastic modulus at 0.99 ° C. is 2000N / mm ² or more 4000 N / mm ² or less, a specific gravity of 1.2 or more 1. 3 below, the tensile modulus at 23 ° C. is 2000N / mm ² or more 4000 N / mm ² or less, a loss tangent at 20 ° C. was 0.010 or more. Therefore, the film made of the polyetherketoneketone resin in each of the examples had high heat resistance, and thus was excellent in durability and also had excellent acoustic characteristics. Further, the film thickness tolerance was within ± 10%, and no problem was found with respect to film forming suitability.

In contrast, films made of polyether ether ketone resin in Comparative Example has a specific gravity of 1.2 to 1.3, a tensile modulus at 23 ° C. is 2000N / mm ² or more 4000 N / mm ² or less, loss at 20 ° C. The tangent was 0.010 or more, the film thickness tolerance was within ± 10%, and no problems were recognized in the acoustic characteristics and film forming suitability.
However, since the glass transition point was less than 150 ° C. and the tensile modulus at 150 ° C. was less than 2000 N / mm ² , the heat resistance was low, and there was a problem in durability when used for a diaphragm.

  The method for manufacturing a film for a diaphragm of a speaker according to the present invention is used in the field of manufacturing a speaker incorporated in a portable device or the like.

Reference Signs List 1 molding material 2 film 3 laminated intermediate 4 elastomer layer 5 primer 10 melt extrusion molding machine (extrusion molding machine)
12 Inert gas supply pipe 13 T die 17 Crimping roll 18 Cooling roll 19 Winding machine 20 Winding pipe

Claims (4)

A method for producing a film for a diaphragm of a speaker, which forms a film using a resin-containing molding material,
A molding material containing a polyetherketone ketone resin is melt-kneaded, and a film is continuously extruded from a die into a band shape using the molding material, and the extruded film is sandwiched between a pressing roll and a cooling roll. By cooling in, the thickness of the cooled film to 2μm or more and 110μm or less,
The tensile elastic modulus at 23 ° C. of the film after cooling with a 2000N / mm ² or more 4000 N / mm ² or less, a tensile modulus at 0.99 ° C. the film after cooled to 2000N / mm ² or more 4000 N / mm ² or less, A method for producing a diaphragm film for a speaker, wherein the specific gravity of the film after cooling is 1.2 or more and 1.4 or less, and the loss tangent at 20 ° C. of the film after cooling is 0.010 or more.   2. A diaphragm for a speaker according to claim 1, wherein the molding material is supplied while supplying an inert gas to the extruder, and at least the temperature of the cooling roll of the pressure-bonding roll and the cooling roll is adjusted to 50 ° C. or more and 260 ° C. or less. Film production method.   The method for producing a film for a speaker diaphragm according to claim 1 or 2, wherein the cooled film is laminated and adhered to an elastomer layer having a thickness of 10 µm or more and 100 µm or less, and these are thermoformed.   The method for producing a film for a speaker diaphragm according to claim 3, wherein the durometer hardness of the elastomer layer made of a silicone resin when measured with a durometer type A according to JIS K 6253 is from A10 to A90.

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