JP2022077360A - Laminate film - Google Patents

Abstract

To provide a new laminate film which is suitably suppressed in the generation of winding slip between a protective film of a winding body and a base material film when the winding body is made by winding the film as the protective film of an adhesive layer of a build-up film together with the base material film, and a physical external force is added to the winding body, and which can reduce accumulation of ethylene components on a vertical stretching roll in a film production process.SOLUTION: A laminate film comprises: a core layer comprising a composition (B) containing a homopolypropylene (b1); and a skin layer formed at least on one surface side of the core layer, and comprising a composition (A) containing a propylene-based elastomer (a1), an ethylene/propylene block copolymer (a2), and an ethylene/propylene random copolymer (a3). The composition (A) has a loss tangent tanδ at a vibration frequency of 1 Hz and a temperature of 20°C of 0.06 or more, and the composition (A) has a total percentage content of ethylene and butene of 8.0 mass% or more.SELECTED DRAWING: None

Description

The present invention relates to a laminated film. Specifically, the present invention relates to a laminated film having a core layer and a skin layer, which is used as a protective film for a build-up film used for manufacturing electronic components, for example.

Since polypropylene film is excellent in light weight, thermal stability and mechanical stability, it is widely used as an industrial material film including packaging. Especially in recent years, the low surface energy of polypropylene film has been utilized in the manufacturing process of electronic parts and electronic substrates, the manufacturing process of thermosetting resin members such as fiber-reinforced plastics, the manufacturing process of photosensitive films, etc. Widely used as a mold material.

Patent No. 6354634 Japanese Unexamined Patent Publication No. 2018-204002 Patent No. 6341049 JP-A-2017-66395 WO2018 / 079161

Polypropylene film is used as a protective film for protecting an adhesive layer in a build-up film used for manufacturing electronic parts, for example, and is wound, stored, distributed, etc. as a build-up film roll and used. Has been done. The build-up film is composed of a laminated body in which a base film (PET film, etc.), an adhesive layer (an uncured or semi-cured thermosetting resin that serves as a sealing material for an electronic substrate), and a protective film are laminated. Have. In such a build-up film, the pressure-sensitive adhesive layer (uncured or semi-cured thermosetting resin) is used in the winding step after the protective film is bonded onto the pressure-sensitive adhesive layer applied to the base film. Since is soft, when the winding tension is increased, the adhesive layer tends to protrude from the end face of the wound body. Therefore, in the winding process, the thermosetting resin is wound with a low winding tension so as not to protrude. Then, in the transportation process of the take-up body of the build-up film, there is a problem that the winding misalignment is likely to occur between the protective film (polypropylene film) contained in the take-up body and the base film due to the vibration of the conveyor. There is.

Further, in order to improve the processability of the polypropylene film, it is generally practiced to add an anti-blocking agent to adjust the frictional force. However, the polypropylene film used for the build-up film may affect the insulation performance of the thermosetting resin (insulating member that seals the electronic substrate) that comes into contact with it, so the addition of anti-blocking agents and the like is limited. Is provided. Specifically, when the surface of the polypropylene film is made uneven by adding an anti-blocking agent, when the polypropylene film (protective film) is peeled off from the thermosetting resin, the anti-blocking agent present on the surface of the polypropylene film falls off. May transfer to thermosetting resin. In the portion where the antiblocking agent is transferred on the surface of the thermosetting resin, the layer thickness of the thermosetting resin becomes thinner than in other portions, and the insulation performance may be deteriorated. Therefore, the polypropylene film used for the build-up film has a limitation on the addition of fine particles such as an anti-blocking agent.

As a polypropylene film to which an appropriate take-up property is imparted without blending an anti-blocking agent or the like, for example, a film containing polypropylene and a polyolefin other than polypropylene and having an appropriate roughness on the film surface due to the compatibility of the resin. Is known (Patent Document 1). Such a polypropylene film is considered to be suitable for workability as a work in process. However, when the film described in Patent Document 1 is used as a protective film for a build-up film, the roughening of the film surface reduces the contact area with the mating base film (PET film, etc.) due to air entrainment during winding. On the other hand, if the film surface is roughened, the true contact area with the mating base film (PET film, etc.), which has high smoothness, decreases, so the film is wound up as a build-up film. There is a problem that winding misalignment is likely to occur between the protective film (polypropylene film) and the base film (PET film or the like) due to the vibration during transportation of the body.

Further, as a preventive measure against winding misalignment of the build-up film winder, for example, a core layer and a skin layer laminated on at least one side of the core layer are provided, and the ethylene content in the skin layer is within a predetermined range. A laminated film that suppresses winding misalignment with a mating base film (PET film or the like) by adjusting the inside is known (Patent Document 2). However, in the laminated film described in Patent Document 2, the ethylene content in the skin layer is adjusted within a predetermined range to control the winding deviation of the build-up film winder to a level that can be used as a product. However, the prevention of winding misalignment of the build-up film winder is insufficient, and there is room for improvement. Further, in the laminated film described in Patent Document 2, low molecular weight components derived from ethylene in the skin layer are gradually deposited on the roll surface used for producing the thermoplastic film. After that, the accumulated ethylene component is re-transferred to the film and causes foreign matter defects, so that there is a problem that the ethylene content in the skin layer must be reduced as much as possible.

Further, in order to improve the followability with various surfaces, an elastomer-containing film / sheet using an elastomer (rubber) that flexibly imitates the shape change of the other party (flexibility) is known. (Patent Documents 3 to 5). However, the films described in Patent Documents 3 to 4 improve the adhesive force with the adherend to which they come into contact, and are not a means for preventing winding misalignment. Further, the film described in Patent Document 5 is provided with an elastomer layer to control the loss tangent of the elastomer layer to improve vibration damping (action of converting vibration into heat energy and dampening it). , It is not a means to prevent winding misalignment.

According to the present invention, when a protective film for an adhesive layer is wound together with a base film to form a wound body, when a physical external force is applied to the wound body, the protective film and the base material of the wound body are applied. To provide a novel laminated film capable of preferably suppressing the occurrence of winding misalignment with a film and further reducing the accumulation of ethylene components on the surface of a transport roll such as a longitudinally stretched roll in a film manufacturing process. Is the main purpose. The laminated film can be suitably used as a protective film for an adhesive layer of a build-up film used for manufacturing electronic components. Further, the laminated film can also be used as a protective film in various fields such as a manufacturing process of a thermosetting resin member (adhesive layer) such as a fiber reinforced plastic. Another object of the present invention is to provide a novel wound body in which the occurrence of winding misalignment is suppressed by using the laminated film.

As a result of diligent studies to solve the above problems, the present inventors have made a propylene-based elastomer in the skin layer in a laminated film including a core layer and a skin layer laminated on at least one side of the core layer. After forming from a predetermined resin composition containing (a1), the content of ethylene and butene in the skin layer is set within a predetermined range, and further, the loss tangent of the skin layer of the cast raw sheet (unstretched) is set. By controlling tan δ, the protective film of the wound body is wound together with the base film as the protective film of the pressure-sensitive adhesive layer, and when a physical external force is applied to the wound body, the protective film of the wound body is applied. It has been found that the occurrence of winding misalignment between the film and the base film is suitably suppressed, and that the deposition of ethylene components on the roll surface in the film manufacturing process can be reduced. The present invention has been completed by further studies based on such findings.

That is, the present invention includes the following.
Item 1. A core layer made of the composition (B) containing homopolypropylene (b1),
A composition (A) formed on at least one side of the core layer and containing a propylene-based elastomer (a1), an ethylene / propylene block copolymer (a2), and an ethylene / propylene random copolymer (a3). A skin layer consisting of
Equipped with
The composition (A) has a loss tangent tan δ of 0.06 or more at a vibration frequency of 1 Hz and a temperature of 20 ° C.
The composition (A) is a laminated film having a total content of ethylene and butene of 8.0% by mass or more.
Item 2. Item 2. The laminated film according to Item 1, wherein the composition (A) has an ethylene content of 35.0% by mass or less.
Item 3. The composition (A) has a content of the propylene-based elastomer (a1) of 5 to 65 parts by mass and a content of the ethylene / propylene block copolymer (a2) of 30 to 90 parts by mass. Item 2. The laminated film according to Item 1 or 2, wherein the ethylene / propylene random copolymer (a3) has a content of 5 to 65 parts by mass.
Item 4. Item 6. The laminated film according to any one of Items 1 to 3, which is used as a protective film for an adhesive layer of a build-up film.
Item 5. A wound body obtained by winding a build-up film containing the laminated film according to any one of Items 1 to 3.

According to the present invention, as a protective film for the pressure-sensitive adhesive layer of a build-up film, the wound body is wound together with a base film to form a wound body, and when a physical external force is applied to the wound body, the wound body is wound. To provide a novel laminated film capable of preferably suppressing the occurrence of winding misalignment between the protective film and the base film, and further reducing the deposition of ethylene components on the longitudinally stretched roll in the film manufacturing process. Can be done. Such a laminated film can be suitably used, for example, as a protective film for an adhesive layer of a build-up film used for manufacturing electronic components. Another object of the present invention is to provide a novel wound body in which the occurrence of winding misalignment is suppressed by using the laminated film. The take-up body can be configured as a take-up body of a build-up film of an electronic component.

The laminated film according to the present embodiment includes a core layer made of the composition (B) containing homopolypropylene (b1) and a skin layer laminated on at least one side of the core layer. The skin layer contains a propylene-based elastomer (a1), an ethylene / propylene block copolymer (a2), and an ethylene / propylene random copolymer (a3). The loss tangent tan δ of the skin layer at a vibration frequency of 1 Hz and a temperature of 20 ° C. is 0.06 or more. The total content of ethylene and butene in the skin layer is 8.0% by mass or more. Since the laminated film according to the present embodiment has these characteristics, the above-mentioned effect of the present invention "when the film is wound together with the base film as a protective film for the pressure-sensitive adhesive layer to form a wound body, the present invention is concerned. When a physical external force is applied to the take-up body, it is preferable to suppress the occurrence of winding misalignment between the protective film of the take-up body and the base film, and further, ethylene on the roll surface in the film manufacturing process. It is possible to reduce the accumulation of components. "

Further, the winding body according to the present embodiment is a winding body of a laminated body using the laminated film according to the present embodiment as a protective film. For example, it can be a wound body obtained by winding a build-up film including the laminated film of the present embodiment. As a specific configuration of the winding body according to the present embodiment, the base film, the pressure-sensitive adhesive layer, and the laminated film according to the present embodiment are laminated in this order, and the pressure-sensitive adhesive layer and the laminated body. Either the skin layer or the core layer of the laminated film is in contact with each other, and the laminated body can be wound around the winding core. The winding body according to the present embodiment uses the laminated film according to the present embodiment as a protective film, so that when a physical external force is applied to the winding body, the protective film and the base film of the winding body are used. The occurrence of winding misalignment between the two is preferably suppressed.

Hereinafter, the laminated film according to the present embodiment and the winding body using the laminated film will be described in detail. In addition, in this specification, "-" in a numerical range means the above and the following. That is, the notation α to β means α or more and β or less, or β or more and α or less, and includes α and β as a range.

<1. Laminated film>
The laminated film according to the present embodiment includes a core layer and a skin layer laminated on at least one side of the core layer.

The thickness of the laminated film according to the present embodiment can be appropriately selected depending on the use of the laminated film. For example, from the viewpoint of suitably using the laminated film according to the present embodiment as a protective film for a build-up film used for manufacturing electronic components, it is preferably 200 μm or less, more preferably 100 μm or less, still more preferably 80 μm or less. It is particularly preferably 60 μm or less, and examples of the lower limit of the thickness include, for example, 3 μm or more, preferably 5 μm or more, and more preferably 10 μm or more. The thickness of the laminated film can be measured according to JIS C-2151 using a micrometer (JIS B-7502).

The laminated film according to the present embodiment is preferably a stretched laminated film, and more preferably a biaxially stretched laminated film.

(Core layer)
The resin forming the core layer is not particularly limited as long as it can function as a support for the skin layer, but polypropylene resin is preferable.

Polypropylene resins suitable for forming the core layer include a homopolymer of propylene, a copolymer of propylene and ethylene, and an α-olefin having 4 to 20 carbon atoms of propylene and ethylene (for example, ethylene). At least one polymer such as butene, pentene, hexene and the like) can be mentioned. Among these, since it is easy to increase the mechanical strength and heat resistance of the core layer and the surface of the core layer can be appropriately roughened, it is possible to use one polypropylene homopolymer alone or a mixture of two or more. preferable.

The content of the polypropylene resin in the resin forming the core layer is not particularly limited, but is preferably 90% by mass or more, more preferably 95% by mass or more, still more preferably 98 from the viewpoint of functioning as a support for the skin layer. It is mass% or more.

The melt flow rate (MFR) of the polypropylene resin is preferably 0.5 g / 10 min to 9.0 g / 10 min, more preferably 1.0 g / 10 min to 6.0 g / 10 min, and even more preferably. Is 2.0 g / 10 minutes to 5.0 g / 10 minutes. When the melt flow rate of the polypropylene resin is at least the above lower limit, sufficient resin fluidity can be obtained, the thickness of the cast raw sheet can be easily controlled, and a film stretched with high accuracy in the width direction can be easily produced, which is preferable. .. Further, when the melt flow rate of the polypropylene resin is not more than the above upper limit, it is easy to improve the mechanical properties of the obtained sheet and to improve the stretchability, which is preferable. In the present specification, the MFR of the resin conforms to JIS K-7210 (1999), and uses a melt flow indexer (for example, a melt indexer manufactured by Toyo Seiki Seisakusho Co., Ltd.) at 230 ° C. and a load of 21.18 N. Can be measured.

The weight average molecular weight (Mw) of the polypropylene resin is preferably 200,000 to 600,000, more preferably 250,000 to 500,000. When the weight average molecular weight Mw of the polypropylene resin is at least the above lower limit, sufficient resin fluidity can be obtained, the thickness of the cast raw sheet can be easily controlled, and a film suitable for a core layer stretched with high accuracy in the width direction. Is preferable because it is easy to produce. Further, when the weight average molecular weight Mw of the polypropylene resin is not more than the above upper limit, it is preferable because the mechanical properties of the obtained sheet can be easily improved, the stretchability is improved, and a cheap film suitable for the core layer can be obtained.

The molecular weight distribution (Mw / Mn) calculated as the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the polypropylene resin is preferably 4 or more, more preferably 4.5 or more. When the molecular weight distribution (Mw / Mn) of the polypropylene resin is at least the above lower limit, β crystals can be sufficiently generated in the cast raw sheet before stretching, and appropriate strength as a core layer can be easily obtained, which is preferable. .. The upper limit of the molecular weight distribution (Mw / Mn) of the polypropylene resin is not particularly limited, but is preferably 10 or less.

The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polypropylene resin can be measured by a gel permeation chromatography (GPC) method. The GPC device used in the GPC method is not particularly limited, and is a commercially available high-temperature GPC measuring machine capable of analyzing the molecular weight of polyolefins (for example, a high-temperature GPC measuring machine with a built-in differential refractometer (RI) manufactured by Tosoh Corporation). , HLC-8121GPC-HT) and the like can be used. In this case, for example, it can be measured by the GPC column, the column temperature, the eluent, and the flow rate as described in Examples. Usually, a calibration curve is prepared using standard polystyrene, and a weight average molecular weight (Mw) and a number average molecular weight (Mn) are obtained by polystyrene conversion.

The thickness of the core layer can be appropriately selected depending on the use of the laminated film according to the present embodiment. For example, from the viewpoint of suitably using the laminated film according to the present embodiment as a protective film for a build-up film used for manufacturing electronic components, 50% or more and 93% or less of the total thickness of the laminated film can be mentioned. Be done. The thickness of the core layer can be measured by cutting the laminated film and observing the cross section with a microscope.

(Skin layer)
The skin layer is laminated on at least one side of the core layer. In the laminated film according to the present embodiment, at least one surface may be composed of the surface of the skin layer.

In the laminated film according to the present embodiment, the core layer comes into contact with the surface of the object to be protected, so that the object to be protected can be suitably protected. For example, when the laminated film is used as a protective film for the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer applied to the base film and the core layer are in contact with each other, and the film is wound together with the base film to form a wound body. When a physical external force is applied to the wound body, it is possible to suitably suppress the occurrence of winding misalignment between the protective film of the wound body and the base film.

Further, the skin layer may be laminated on both sides of the core layer. In the laminated film according to the present embodiment, since the surfaces on both sides are composed of the surfaces of the skin layer, the skin layer of the laminated film can suitably protect the object to be protected, and further, the wound body It is possible to suitably suppress the occurrence of winding misalignment between the protective film and the base film. When skin layers are formed on both sides of the core layer, the resin composition forming each skin layer, the thickness of the skin layer, the surface characteristics of the skin layer, etc. may be the same or different. May be.

In the laminated film according to the present embodiment, a skin layer may be laminated on one side of the core layer, and a layer different from the skin layer may be laminated on the other side. It is preferable that the layer different from the skin layer is also formed of polypropylene resin.

The skin layer contains a propylene-based elastomer (a1) and a propylene-based copolymer. Specifically, the skin layer is formed from a resin composition (A) containing a propylene-based elastomer (a1), an ethylene / propylene block copolymer (a2), and an ethylene / propylene random copolymer (a3). can do.

In the skin layer, the mass ratio of the propylene-based elastomer (a1), the ethylene / propylene block copolymer (a2), and the ethylene / propylene random copolymer (a3) (propylene-based elastomer (a1): ethylene / propylene block copolymer weight). The combined (a2): ethylene / propylene random copolymer (a3)) is not particularly limited, but the surface characteristics (dynamic friction coefficient, etc.) of the skin layer are suitable, and the ethylene component on the roll surface in the film manufacturing process is suitable. From the viewpoint of reducing the deposition of the polymer and preferably exerting the effect of the present invention, it is preferably about 5:90: 5 to 40:40:20, more preferably about 5:90: 5 to 30:40:30. It is more preferably about 5:90: 5 to 30:60:10, and particularly preferably about 5:90: 5 to 20:70:10.

The contents of the propylene-based elastomer (a1), the ethylene-propylene block copolymer (a2), and the ethylene-propylene random copolymer (a3) in the skin layer are not particularly limited, but the effects of the present invention are fully exhibited. From the viewpoint, the propylene-based elastomer (a1) is 5 to 65 parts by mass, the ethylene / propylene block copolymer (a2) is 30 to 90 parts by mass, and the ethylene / propylene random copolymer (a3) is 5 to 65 parts by mass. It is preferably in the range. Further, from the viewpoint of effectively suppressing the contamination of the ethylene component on the roll surface, the propylene-based elastomer (a1) is 5 to 55 parts by mass, the ethylene / propylene block copolymer (a2) is 30 to 80 parts by mass, and ethylene. More preferably, the propylene random copolymer (a3) is in the range of 15 to 65 parts by mass. Further, from the viewpoint of effectively suppressing the occurrence of winding misalignment, the propylene-based elastomer (a1) is 15 to 55 parts by mass, the ethylene / propylene block copolymer (a2) is 30 to 70 parts by mass, and ethylene / propylene random. It is more preferable that the copolymer (a3) is in the range of 15 to 55 parts by mass.

Similarly, the content of the propylene-based elastomer (a1), the ethylene-propylene block copolymer (a2), and the ethylene-propylene random copolymer (a3) in the skin layer is 5 to 65 mass for the propylene-based elastomer (a1). %, The ethylene / propylene block copolymer (a2) is preferably in the range of 30 to 90% by mass, and the ethylene / propylene random copolymer (a3) is preferably in the range of 5 to 65% by mass. Further, from the viewpoint of effectively suppressing the contamination of the ethylene component on the roll surface, the propylene-based elastomer (a1) is 5 to 55% by mass, the ethylene / propylene block copolymer (a2) is 30 to 80% by mass, and ethylene. It is more preferable that the propylene random copolymer (a3) is in the range of 15 to 65% by mass. Further, from the viewpoint of effectively suppressing the occurrence of winding misalignment, the propylene-based elastomer (a1) is 15 to 55% by mass, a2 is 30 to 70% by mass, and the ethylene / propylene random copolymer (a3) is 15 to 55% by mass. It is more preferably in the range of 55% by mass.

The propylene-based elastomer (a1) used in the composition (A) contains a propylene-derived structural unit, an ethylene-derived structural unit, and an α-olefin-derived structural unit having 4 to 20 carbon atoms. It is an α-olefin ternary polymer. Specific examples of α-olefins having 4 to 20 carbon atoms include 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-dodecene, 1-hexadecene, 3 -Methyl-1-butene, 4-methyl-1-pentene and the like can be mentioned.

Examples of the propylene-based elastomer (a1) used in the composition (A) include a propylene / ethylene / 1-butene copolymer. The propylene-based elastomer (a1) has 50 to 87 mol% of propylene-derived constituent units, 10 to 25 mol% of ethylene-derived constituent units, and 3 to 25 mol% of 1-butene-derived constituent units. Polymers are preferred.

As the propylene-based elastomer (a1) used in the composition (A), a copolymer having an ethylene content of 1 to 15% by mass is preferable, and a copolymer having an ethylene content of 3 to 12% by mass is more preferable. preferable.

As the propylene-based elastomer (a1) used in the composition (A), a copolymer having a 1-butene content of 1 to 15% by mass is preferable, and a copolymer having a 1-butene content of 1 to 12% by mass is preferable. Coalescence is more preferred.

The MFR of the propylene-based elastomer (a1) is preferably 3 to 14 g / 10 min, more preferably 5 to 12 g / 10 min, in terms of moldability.

As the ethylene / propylene block copolymer (a2) used in the composition (A), a block copolymer having an ethylene content of 1 to 15% by mass is preferable, and an ethylene content of 3 to 12% by mass is preferable. Block copolymers are more preferred.

The MFR of the ethylene / propylene block copolymer (a2) is preferably 3 to 12 g / 10 min, more preferably 5 to 10 g / 10 min, in terms of moldability.

The weight average molecular weight (Mw) of the ethylene / propylene block copolymer (a2) is not particularly limited, but is preferably 200,000 to 600,000, more preferably 300,000 to 500,000. Further, the molecular weight distribution (Mw / Mn) calculated as the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is preferably 4 or more, and more preferably 5 or more. The method for measuring the weight average molecular weight (Mw) and the number average molecular weight (Mn) is the same as that for the polypropylene resin described above.

As the ethylene / propylene random copolymer (a3) used in the composition (A), a random copolymer having an ethylene content of 0.5 to 6% by mass is preferable, and an ethylene content of 1 to 5% by mass is preferable. % Random copolymer is more preferred.

The MFR of the ethylene / propylene random copolymer (a3) is preferably 5 to 14 g / 10 min, more preferably 7 to 12 g / 10 min in terms of moldability.

The weight average molecular weight (Mw) of the ethylene / propylene random copolymer (a3) is not particularly limited, but is preferably 200,000 to 600,000, more preferably 300,000 to 500,000. Further, the molecular weight distribution (Mw / Mn) calculated as the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is preferably 4 or more, and more preferably 5 or more. The method for measuring the weight average molecular weight (Mw) and the number average molecular weight (Mn) is the same as that for the polypropylene resin described above.

In the laminated film according to the present embodiment, the content of propylene in the skin layer is preferably 65% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, and particularly preferably 85% by mass or more. Is.

In the laminated film according to the present embodiment, the total content of ethylene and butene in the skin layer may be 8.0% by mass or more. Ethylene in the skin layer is suitable from the viewpoint of making the surface characteristics (dynamic friction coefficient, etc.) of the skin layer suitable, reducing the accumulation of ethylene components on the roll surface in the film manufacturing process, and appropriately exerting the effect of the present invention. The total content of ethylene and butene is preferably in the range of 8.0 to 35.0% by mass, more preferably in the range of 8.0 to 25.0% by mass. From the same viewpoint, the content of ethylene in the skin layer is preferably 35.0% by mass or less, more preferably 25.0% by mass or less, and further preferably 15.0% by mass or less. Yes, more preferably 10.0% by mass or less, and particularly preferably 9.5% by mass or less. The lower limit of the ethylene content is, for example, 5.0% by mass or more, 7.0% by mass or more, and the like. From the same viewpoint, the content of butene in the skin layer is preferably 35.0% by mass or less, more preferably 25.0% by mass or less, and further preferably 5.0% by mass or less. Yes, and particularly preferably 3.0% by mass or less. The lower limit of the butene content is preferably, for example, 0.1% by mass or more, 0.3% by mass or more, 0.5% by mass or more, and the like. The content of ethylene and butene in the skin layer is the ethylene unit contained in the propylene-based elastomer (a1), the ethylene / propylene block copolymer (a2), and the ethylene / propylene random copolymer (a3). And derived from butene units. The content of ethylene and butene in the skin layer is determined by using a nuclear magnetic resonance apparatus or the like, respectively. In the present invention, more specifically, AVANCE NEO700 manufactured by Bruker is used, and the observation nucleus is measured at ¹³ C (176.08 MHz).

The measurement mode is reverse gated decoupling (quantitative method), the shift reference is 5 chains of propylene units (mm mm) (21.95 ppm), the number of integrations is 2048, and the temperature is 130 ° C.

In addition, the monomer composition was determined from the integral value of the main chain methylene carbon based on the monomer chain, "GJ Ray et al., Macromolecules 1977, 10, p.773-778", "Y.D. Zhang et al.". , Polymer. J. 2003, 35, p. 551-559 ”. For the total content of ethylene and butene in the skin layer, the ethylene content and butene content were measured by the above method for each of the resins used to form the skin layer, and the mixing ratio of each resin in the skin layer was determined. It is a value calculated in consideration.

In the laminated film according to the present embodiment, a skin layer single film cast raw sheet made of the composition (A) is cut into strips and measured using a dynamic viscoelastic device, having a vibration frequency of 1 Hz and a temperature of 20 ° C. The loss tangent tan δ is 0.06 or more. Since the surface of the skin layer of the laminated film according to the present embodiment has such surface characteristics, it is possible to suitably exert the above-mentioned effects of the present invention.

The skin layer single film cast raw sheet made of the composition (A) is cut into strips of 40 mm in the vertical direction and 8 mm in the horizontal direction, and the loss tangent tan δ at a vibration frequency of 1 Hz and a temperature of 20 ° C. is measured by the following measuring method. To. As a more specific measurement method, the method described in the examples is adopted.

[Loss tangent tanδ]
Dynamic viscoelasticity is measured using a dynamic viscoelasticity measuring machine (for example, a "viscoelasticity measuring device (model: DMS6100)" manufactured by Seiko Instruments Co., Ltd. A skin comprising the composition (A). The layered single film cast raw sheet is cut into strips and composed according to JIS-K7244 (1999 edition) under the measurement conditions of tensile mode, vibration frequency 1 Hz, chuck distance 20 mm, and heating rate 5 ° C / min. The temperature dependence of the skin layer single-film cast raw fabric sheet made of the material (A) was measured. From this measurement result, the loss tangent tan δ at 20 ° C. was obtained from the temperature dispersion of the loss tangent.

The laminated film according to the present embodiment has a dynamic friction coefficient of 1.0 or more at 5.56 gf / cm ² pressure measured by superimposing the surface of the skin layer and the biaxially stretched polyester film. Further, the dynamic friction coefficient at a pressure of 33.33 gf / cm ² measured by superimposing the surface of the skin layer and the biaxially stretched polyester film is 1.0 or more. Since the surface of the skin layer of the laminated film according to the present embodiment has such surface characteristics, it is possible to suitably exert the above-mentioned effects of the present invention.

With respect to the surface of the skin layer, the dynamic friction force D1 at 5.56 gf / cm ² pressure and the dynamic friction force D2 at 33.33 gf / cm ² pressure are measured by the following methods for measuring the frictional force, respectively. As a more specific measurement method, the method described in the examples is adopted.

[Friction force]
Various frictional forces are measured using a surface measuring machine (for example, "HEIDO Tribo Gear (model: TYPE14FW)" manufactured by Shinto Kagaku Co., Ltd.). The laminated film is cut out in a vertical direction of 20 cm and a horizontal direction of 3 cm to obtain a test film. Next, the test film is set on a 30 mm flat indenter (contact area 9 cm ² ) without wrinkles. At this time, the test film is set so that the skin layer is on the outside. Next, a biaxially stretched polyester film used for measuring the frictional force of the skin layer (arithmetic average height (Sa) 0.001 μm, squared average square root height (Sq) 0.001 μm, squared average square root inclination (Sdq) 0. 001, area expansion ratio of interface (Sdr) 0.000%, core level difference (Sk) 0.002 μm, protrusion valley height (Svk) 0.001 μm, protrusion valley space volume (Vvv) 0.000 ml / M ² , core space volume (Vvc) 0.001 ml / m ² , core volume (Vmc) 0.001 ml / m ² , maximum height (Sz) 0.08 μm, thickness 50 μm) in the vertical direction 20 cm Cut out to 8 cm in the lateral direction, and set it on a movable table so that the untreated surface that has not been subjected to surface modification treatment such as corona discharge faces the upper surface in a wrinkle-free state. The biaxially stretched polyester film has an arithmetic average height Sa (ISO25178) of 0.001 μm, a maximum height Sz (ISO25178) of 0.08 μm, a thickness (JIS C-2318) of 50 μm, and a static friction coefficient (JIS K-7125). ) Is 0.46, the dynamic friction coefficient (JIS K-7125) is 0.40, the haze (JIS K-7105) is 0.9%, and the total light transmittance (JIS K-7105) is 92.0%. Yes, it is in contact with the skin layer and is used to measure the static friction coefficient and the dynamic friction coefficient.

In this state, the dynamic friction coefficient D1 at 5.56 gf / cm ² pressure measured by superimposing the surface of the skin layer of the test film and the biaxially stretched polyester film is set to a table speed of 100 mm / min and a vertical load of 50 gf. (Pressure conversion value 5.56 gf / cm ² ), displacement amount 60 mm or more (one-way movement), data sampling speed every 50 ms, measurement temperature 23 ° C, measurement humidity 50% RH. From the values obtained in each of the three measurements, the dynamic friction coefficient D1 (the average value between the displacement amounts of 1 to 60 mm) is extracted.

Further, the dynamic friction coefficient D2 at 33.33 gf / cm ² pressure measured by superimposing the surface of the skin layer of the test film and the biaxially stretched polyester film is a table speed of 100 mm / min and a vertical load of 300 gf (pressure). Converted value 33.33 gf / cm ² ), displacement amount 60 mm or more (one-way movement), data sampling speed every 50 ms, measurement temperature 23 ° C, measurement humidity 50% RH. From the values obtained in each of the three measurements, the dynamic friction coefficient D2 (the average value between the displacement amounts of 1 to 60 mm) is extracted.

The laminated film of the present embodiment is preferably a surface-roughened laminated film in which the surface of the skin layer is roughened. Specifically, the laminated film of the present embodiment has a skin layer having a surface roughness of at least one of the following (a) to (e) from the viewpoint of more preferably exerting the above-mentioned effect of the present invention. It is preferable to satisfy one, more preferably two or more, further preferably three or more, and particularly preferably all.

(A) The root mean square height (Sq) is 0.48 to 1.12 μm.
(B) The area expansion ratio (Sdr) of the interface is 0.54 to 3.01%.
(C) The level difference (Sk) of the core portion is 1.03 to 2.78 μm.
(D) The height of the protruding mountain portion (Spk) is 0.68 to 1.42 μm.
(E) The protruding valley height (Svk) is 0.17 to 0.64 μm.

The above-mentioned physical properties regarding the surface roughness of the skin layer are measured by the following method for measuring the surface roughness. As a more specific measurement method, the method described in the examples is adopted.

[Surface roughness]
An optical interferometry non-contact surface shape measuring machine (for example, "VertScan 2.0 (model: R5500GML)" manufactured by Ryoka System Co., Ltd.) is used. As a sample for measurement, a film is cut into an arbitrary size of about 20 cm square, and the film is set on a measurement stage using an electrostatic contact plate or the like in a state where wrinkles are sufficiently smoothed out. First, the WAVE mode is used for measurement, a 530 white filter and a 1 × BODY lens barrel are applied, and a 10x objective lens is used to perform measurement per field of view (470 μm × 353 μm). This operation is performed at 10 locations at 1 cm intervals in the flow direction from the central location in both the flow direction and the width direction of the surface of the skin layer of the target sample film. Next, the obtained data is subjected to noise removal processing by a median filter (3 × 3), and then Gaussian filter processing with a cutoff value of 176 μm is performed to remove undulation components. As a result, the state of the surface of the skin layer can be appropriately measured. Next, analysis is performed using the "ISO parameter" in the plug-in function "bearing" of the analysis software "VS-Viewer" of "VertScan 2.0", and Sq (μm), Sdr (%), Sk (μm). ), Spk (μm), Svk (μm), and the average value of each value obtained at the above 10 points is calculated.

The thickness of the skin layer can be appropriately selected depending on the use of the laminated film according to the present embodiment. For example, from the viewpoint of suitably using the biaxially stretched surface film according to the present embodiment as, for example, a protective film for a build-up film used for manufacturing electronic components, the lower limit is preferably 0.05 μm or more. , More preferably 0.1 μm or more, further preferably 1 μm or more, and the upper limit is preferably 80 μm or less, more preferably 50 μm or less, still more preferably 30 μm or less, and particularly preferably 10 μm or less. The thickness of the skin layer is preferably 0.5% or more, more preferably 1% or more, still more preferably 3% or more, still more preferably 5% or more, based on the total thickness of the laminated film. , Particularly preferably 10% or more. The thickness of the skin layer is preferably 50% or less, more preferably 30% or less, still more preferably 25% or less, still more preferably 20% or less, based on the total thickness of the biaxially stretched surface film. Especially preferably, it is 15% or less. When skin layers are formed on both sides of the laminated film according to the present embodiment, it is preferable that the thickness of the skin layers on both sides is within the thickness range described above. Further, when skin layers are formed on both sides of the laminated film according to the present embodiment, the thicknesses of the skin layers may be the same or different from each other. The thickness of the skin layer can be measured by cutting the laminated film and observing the cross section with a microscope.

The skin layer and the core layer each have an ash content of 100 ppm or less. The ash content is caused by the residue of the polymerization catalyst and the like, and causes minute foreign substances (fish eyes). When the ash content is 100 ppm or less, preferably 50 ppm or less, fish eyes can be prevented. The ash content can be adjusted by a method of controlling the type and amount of the catalyst used at the time of polymerization of the resins constituting the skin layer and the core layer, respectively.

In the present specification, the ash contents of the skin layer and the core layer are measured as follows according to ISO3451-1, respectively. The resin forming the skin layer or the core layer is placed in a crucible, heated in a muffle furnace at 750 ° C. for 1 hour, and the mass of the residue in the crucible is measured. Then, the ratio of the mass of the residue in the crucible to the mass of the resin put into the crucible is calculated, and this is used as the ash content.

The skin layer and the core layer may each contain an additive. The additive is not particularly limited, and a known additive added to the resin film can be used. As the additive, an additive generally used for polypropylene resin can be used. Examples of the additive include stabilizers such as antioxidants, chlorine absorbers and ultraviolet absorbers, lubricants, plasticizers, flame retardants, antistatic agents, colorants and the like. Such additives may be added to the skin layer or core layer as long as the effects of the present invention are not impaired. However, from the viewpoint of suitably using the biaxially stretched surface film according to the present embodiment as a protective film for a build-up film used for manufacturing electronic components, the skin layer may be prepared with an anti-blocking agent or the like. It is preferable not to add a component that may transfer to the protected member and affect the characteristics of the protected member.

The laminated film according to this embodiment can be suitably used as a protective film for an adhesive layer of a build-up film used for manufacturing electronic components. Further, the laminated film can also be used as a protective film or the like in various fields such as a manufacturing process of a thermosetting resin member such as a fiber reinforced plastic.

The laminated film according to the present embodiment can be obtained as a film in which the core layer and the skin layer are laminated, for example, by extrusion-molding the resin composition forming the core layer and the skin layer. For example, in the case of producing a laminated film as a biaxially stretched laminated film, the core layer before stretching and the skin layer before stretching are laminated by extrusion molding the resin composition forming the core layer and the skin layer. It can be manufactured by the step (i) of manufacturing the cast raw sheet and the step (ii) of biaxially stretching the cast raw sheet. Specific examples of the step (i) and the step (ii) are illustrated below.

In the step (i), first, the resin compositions forming the core layer and the skin layer are melt-kneaded at 200 to 260 ° C. in an extruder, merged by a merging device, and extruded from a T-die. At this time, it is preferable to remove coarse foreign matter from each resin by using a polymer filter on the upstream side of the merging device.

The merging is performed in the pipe before the T die, the method performed by the laminating unit provided in the resin introduction portion of the T die (feed block method), and the method of laminating the resin after widening in the T die (manifold laminating method). ) Etc. can be used by a known method. Among these, the manifold laminating method is superior in terms of laminating thickness accuracy, but it can be appropriately selected from these in consideration of economic efficiency and the like.

Next, the laminate having two or more layers extruded in this way is brought into close contact with at least one metal drum (cooling drum) whose drum surface is controlled to 20 to 100 ° C. by an air knife to form a sheet. Then, for example, a cast raw sheet having a thickness of 500 to 5000 μm is obtained.

Next, in the step (ii), the biaxially stretched laminated film can be manufactured by performing a stretching treatment on the cast raw sheet before stretching. As the stretching treatment, biaxial stretching in the flow (longitudinal, vertical, MD) direction and width (horizontal, TD) direction is preferable, but biaxial stretching in the diagonal direction is also possible as needed. good.

As the stretching method, there are a tubular method, a tenter method, a method of stretching between rolls provided with a peripheral speed difference, and the like, and the two axes can be stretched at the same time or the two axes can be stretched sequentially. Since it is easy to obtain a biaxially stretched laminated film having no thickness unevenness and good flatness, a simultaneous biaxial stretching method by the tenter method, a sequential biaxial stretching method by the tenter method, and a roll having a peripheral speed difference are provided. A sequential biaxial stretching method in which the film is stretched in the flow direction and then stretched in the width direction by the tenter method is preferable.

As a sequential biaxial stretching method, for example, the cast raw sheet is first kept at a temperature of 100 to 160 ° C., passed between rolls provided with a speed difference, or guided to a tenter and stretched 3 to 8 times in the flow direction. After that, it is relaxed by about 0 to 10% as needed. Subsequently, the uniaxially stretched film is guided to a tenter and stretched 6 to 12 times in the width direction at a temperature of 120 to 185 ° C., then relaxed by about 0 to 10% as necessary, heat-fixed, and wound. ..

In the simultaneous biaxial stretching method, the cast raw sheet is guided to a tenter, stretched at a temperature of 120 to 185 ° C. in the flow direction and the width direction to the above-mentioned stretching ratio, and then relaxed by about 0 to 10% as necessary. And heat fixing. Then, the end portion of the obtained biaxially stretched laminated film is trimmed as necessary and then wound up.

<2. Laminated body>
The laminate according to the present embodiment is a laminate using the laminate film according to the present embodiment. The laminate according to the present embodiment has a structure in which the base film, the pressure-sensitive adhesive layer, and the above-mentioned laminated film according to the present embodiment are laminated in this order.

The laminated film according to this embodiment is as described above.

Further, in the laminated body according to the present embodiment, the laminated film according to the present embodiment protects the pressure-sensitive adhesive layer formed on the base film. The material and thickness of the base film and the thermosetting resin are appropriately selected according to the use of the laminate according to the present embodiment. For example, a build-up film used in the manufacture of electronic components has an adhesive layer (an uncured or semi-cured heat such as an epoxy resin that serves as a sealing material for an electronic substrate) on a base film such as a polyethylene terephthalate film. It has a structure of a laminated body in which a curable resin) and a protective film are laminated, and when the wind-up body according to the present embodiment is a wind-up body of a build-up film, the base film is a polyethylene terephthalate film. The pressure-sensitive adhesive layer is preferably formed of an uncured or semi-cured epoxy resin.

The thickness of the base film is not particularly limited, but is, for example, about 10 to 150 μm. The thickness of the pressure-sensitive adhesive layer is not particularly limited, but is, for example, greater than or equal to the conductor thickness of the inner layer circuit board to be laminated, and is about + (10 to 120) μm.

Further, when the laminated film according to the present embodiment is also used as a protective film in various fields such as a manufacturing process of a thermosetting resin member such as a fiber-reinforced plastic, the base film is a polyethylene terephthalate film and an adhesive layer. Is preferably an uncured or semi-cured epoxy resin.

The thickness of the laminated body is not particularly limited, but is, for example, about 50 to 450 μm.

<3. Winder>
The winding body according to the present embodiment is a winding body of a laminated body using the laminated film according to the present embodiment. For example, it can be a wound body obtained by winding a build-up film including the laminated film of the present embodiment. The laminated body constituting the winding body is described in <2. As described in the column of "Laminated body>", the base film, the pressure-sensitive adhesive layer, and the above-mentioned laminated film according to the present embodiment are laminated in this order, and are laminated with the pressure-sensitive adhesive layer. One side of either the skin layer or the core layer of the film is in contact with each other. Further, the laminated body is in the form of being wound around a winding core.

The laminated film according to this embodiment is as described above.

Further, in the wound body according to the present embodiment, the laminated film according to the present embodiment protects the pressure-sensitive adhesive layer formed on the base film. The materials and thicknesses of the base film and the thermosetting resin are used for the winding body according to the present embodiment (specifically, the above-mentioned laminated body in the form of the winding body). It is appropriately selected accordingly. For example, a build-up film used in the manufacture of electronic components has an adhesive layer (an uncured or semi-cured heat such as an epoxy resin that serves as a sealing material for an electronic substrate) on a base film such as a polyethylene terephthalate film. It has a structure of a laminated body in which a curable resin) and a protective film are laminated, and when the wind-up body according to the present embodiment is a wind-up body of a build-up film, the base film is a polyethylene terephthalate film. The pressure-sensitive adhesive layer is preferably formed of an uncured or semi-cured epoxy resin.

The thicknesses of the base film and the pressure-sensitive adhesive layer are the above-mentioned <2. As described in the column of "Laminated body>".

Further, as described above, when the laminated film according to the present embodiment is also used as a protective film in various fields such as a manufacturing process of a thermosetting resin member such as a fiber-reinforced plastic, the base film is a polyethylene terephthalate film. The pressure-sensitive adhesive layer is preferably an uncured or semi-cured epoxy resin.

The thickness of the laminated body constituting the winding body is the above-mentioned <2. As described in the column of "Laminated body>".

The winding core is cylindrical or cylindrical, and the laminate is wound along the circumferential direction of the winding core.

The material of the winding core is not particularly limited, and examples thereof include plastics with little deformation, fiber reinforced plastics, paper, and metals (iron, SUS, aluminum, etc.). Among these, fiber reinforced plastics are preferable because they are lightweight and have high strength. Examples of the core made of fiber-reinforced plastic include those obtained by molding carbon fiber, glass fiber, or the like into a cylindrical shape, impregnating the core with a curable resin such as unsaturated polyester resin, and curing the core.

The size of the winding core can be set according to the size of the target winding body. The outer diameter of the circular cross section of the winding core is, for example, about 50 to 200 mm, more preferably about 80 to 100 mm.

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the examples. Unless otherwise specified, parts and% indicate "parts by mass" and "% by mass", respectively.

[Example 1]
(Core layer)
Homopolypropylene (b1) (MFR = 3.5 g / 10 min at 230 ° C., weight average molecular weight (MW) 290,000, number average molecular weight (Mn) 64,000, molecular weight distribution (Mw / Mn) 4.5). Only the pellets were charged into the extruder I from the hopper and melted to prepare a resin composition forming a core layer.

(Skin layer)
Propylene-based polymer (a1) (MFR at 230 ° C. = 6.0 g / 10 min, ethylene content 0.49 mass% (calculated from measured ethylene content 14.2 mol%), butene content 0.34 mass % (Calculated from the measured value of butene content of 4.9 mol%) and ethylene / propylene block copolymer (a2) (MFR = 8.0 g / 10 min at 230 ° C., ethylene content of 10.27 mass%). (Calculated from the measured value of ethylene content 16.2 mol%)) and ethylene / propylene random copolymer (a3) (MFR = 10 g / 10 min at 230 ° C., ethylene content 0.20 mass% (ethylene content) (Calculated from the measured value of the rate of 6.0 mol%)) was dry-blended at the blending ratio shown in Table 1, melt-kneaded at 230 ° C. using a kneading extruder, and pelletized. Then, the pellet was put into the extruder II from the hopper and melted to prepare a resin composition for forming a skin layer.

[Preparation of laminated film]
The resin compositions (A) and (B) forming the skin layer and the core layer are passed through a polymer filter at 230 ° C. from the multi-manifold die to the skin layer / core layer / skin layer, respectively. It was extruded so as to be a laminated film having a layer structure, and was cooled and solidified while being pressed by air pressure on a cooling drum whose surface temperature was adjusted to 45 ° C. using an air knife to obtain a cast raw sheet having a thickness of 920 μm. Next, the cast raw sheet was heated to 130 ° C. while in contact with a metal roll, and then stretched about 4.6 times in the flow direction between the rolls having a difference in peripheral speed. Next, the uniaxially stretched film was introduced into a hot air oven while being sandwiched between clips, preheated to 180 ° C., stretched about 10 times in the width direction, and subsequently heat-fixed at 170 ° C. while relaxing about 10% in the width direction. A laminated film having a thickness of about 20 μm was continuously obtained. The thickness of the skin layer is 2.5 μm, and the thickness of the core layer is 15 μm, respectively. After trimming the end portion of the obtained laminated film, it was wound around a winding core to obtain a roll-shaped laminated film.

[Examples 2 to 8]
In the preparation of the resin composition (A) for forming the skin layer of Example 1, roll-shaped laminated films were obtained in the same manner as in Example 1 except that the compounding ratios shown in Table 1 were used.

[Comparative Example 1]
Example 1 except that the propylene-based elastomer (a1) used for the skin layer was replaced with low-density polyethylene to obtain the compounding ratio shown in Table 1 in the preparation of the resin composition forming the skin layer of Example 1. A roll-shaped laminated film was obtained in the same manner as above.

[Comparative Example 2]
In the preparation of the resin composition forming the skin layer of Example 1, the propylene-based elastomer (a1) used for the skin layer and the ethylene-propylene random copolymer (a3) were not used, and all the resin compositions were used. A roll-shaped laminated film was obtained in the same manner as in Example 1 except that the compounding ratio was changed to that shown in Table 1 by replacing with the ethylene / propylene block copolymer (a2).

[Comparative Example 3]
In the preparation of the resin composition forming the skin layer of Example 1, the ethylene / propylene block copolymer (a2) and the ethylene / propylene random copolymer weight were not used with the propylene-based elastomer (a1) used for the skin layer. A roll-shaped laminated film was obtained in the same manner as in Example 1 except that the compounding ratio was changed to that shown in Table 1 in place of the coalesced product (a3).

[Comparative Example 4]
In the preparation of the resin composition forming the skin layer of Example 1, the propylene-based elastomer (a1) used for the skin layer, the ethylene / propylene block copolymer (a2), and the ethylene / propylene random copolymer (a3) were used. ) And was not used, and all the resin compositions were replaced with homopolypropylene (b1) (MFR at 230 ° C. = 3.5 g / 10 min) to obtain the compounding ratios shown in Table 1, except that the compounding ratio was the same as that of Example 1. Similarly, a roll-shaped laminated film was obtained.

[Preparation of skin layer single film cast raw sheet]
The resin composition (A) forming each of the skin layers of Examples and Comparative Examples is passed through a polymer filter at 230 ° C. to obtain a single-film cast raw sheet of only the skin layer from the multi-manifold die. The cast raw fabric sheet having a thickness of 150 μm was obtained by cooling and solidifying while pressing it with air pressure using an air knife onto a cooling drum whose surface temperature was adjusted to 45 ° C. The cast raw sheet was used for the measurement of the loss tangent tan δ described later.

[Measurement of molecular weight and molecular weight distribution]
The method for measuring the weight average molecular weight, the number average molecular weight, and the molecular weight distribution of homopolypropylene is a measurement method using size exclusion chromatography (SEC), and the details of the measurement conditions are as follows.
Device: HLC-8321GPC / HT (Detector: Differential Refractometer (RI)) (manufactured by Tosoh Corporation)
Column: TSKgel guardcolumn HHR (30) HT (7.5 mm I.D. x 7.5 cm) x 1 + TSKgel GMHHR-H (20) HT (7.8 mm I.D. x 30 cm) x 3 (manufactured by Tosoh Corporation) )
Eluent: 1,2,4-trichlorobenzene (for GPC manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) + BHT (0.05%)
Flow velocity: 1.0 mL / min Detection condition: polarity- (-)
Injection volume: 0.3 mL
Column temperature: 140 ° C
System temperature: 40 ° C
Sample concentration: 1 mg / mL
Sample pretreatment: The sample was weighed, a solvent (1,2,4-trichlorobenzene with 0.1% BHT added) was added, and the sample was dissolved by shaking at 140 ° C. for 1 hour. Then, it was heated and filtered with a 0.5 μm sintered filter.
Calibration curve: A calibration curve with a fifth-order approximation curve was created using standard polystyrene manufactured by Tosoh Corporation. However, the molecular weight was converted to the molecular weight of polypropylene using the Q-factor. From the obtained calibration curve and SEC chromatogram, a number average molecular weight (Mn), a weight average molecular weight (Mw), and a Z average molecular weight (Mz) were obtained using analysis software for a measuring device. The molecular weight distribution (Mw / Mn) was obtained using the values of Mw and Mn. Moreover, the molecular weight distribution (Mz / Mn) was obtained using the values of Mz and Mn.

[Loss tangent tanδ]
As a dynamic viscoelasticity measuring machine, a "viscoelasticity measuring device (model: DMS6100)" manufactured by Seiko Instruments, Inc. was used. As a measurement sample, a skin layer single film cast raw sheet made of the composition (A) was cut into strips having a length of 40 mm and a width of 8 mm, and according to JIS-K7244 (1999 edition), under the measurement conditions shown below. , The temperature dependence of the cast raw sheet was measured.
Test mode: Tensile mode Chuck distance: 20 mm
Vibration frequency: 1Hz
Strain amplitude: 10 μm
Tension gain: 1.2
Initial force amplitude: 100mN
Temperature range: -60 to 150 ° C
Temperature rise rate: 5 ° C / min
Measurement atmosphere: Measured thickness in nitrogen: From this measurement result using the sheet thickness of the above [Preparation of skin layer single film cast raw sheet], the loss tangent tan δ having a temperature dispersion of 20 ° C. was obtained. The results are shown in Table 1.

[Surface roughness]
As a light interference type non-contact surface shape measuring machine, "VertScan 2.0 (model: R5500GML)" manufactured by Ryoka System Co., Ltd. was used. As a sample for measurement, each laminated film of the example and the comparative example is cut into an arbitrary size of about 20 cm square, and wrinkles are sufficiently stretched so as to eliminate wrinkles, and an electrostatic contact plate or the like is used. And set it on the measurement stage. First, the WAVE mode was used for the measurement, a 530 white filter and a 1 × BODY lens barrel were applied, and a 10x objective lens was used to perform measurement per field of view (470 μm × 353 μm). This operation was performed at 10 locations at 1 cm intervals in the flow direction from the central location in both the flow direction and the width direction of the surface of the skin layer of the target sample film. Next, the obtained data was subjected to noise removal processing by a median filter (3 × 3), and then Gaussian filter treatment with a cutoff value of 176 μm was performed to remove undulation components. As a result, the state of the surface of the skin layer can be appropriately measured. Next, analysis is performed using the "ISO parameter" in the plug-in function "bearing" of the analysis software "VS-Viewer" of "VertScan 2.0", and Sq (μm), Sdr (%), Sk (μm). ), Spk (μm), Svk (μm), and the average value of each value obtained at the above 10 points was calculated. The results are shown in Table 1.

[Friction force]
As a surface measuring machine, "HEIDON Tribo Gear (model: TYPE14FW)" manufactured by Shinto Kagaku Co., Ltd. was used. Each of the laminated films of Examples and Comparative Examples was cut out in a vertical direction of 20 cm and a horizontal direction of 3 cm, respectively, to obtain a test film. Next, the test film was set on a 30 mm flat indenter (contact area 9 cm ² ) without wrinkles. At this time, the skin layer of the test film was set to be on the outside. Next, a biaxially stretched polyester film used for measuring the frictional force of the skin layer (arithmetic average height (Sa) 0.001 μm, squared average square root height (Sq) 0.001 μm, squared average square root inclination (Sdq) 0. 001, area expansion ratio of interface (Sdr) 0.000%, core level difference (Sk) 0.002 μm, protrusion valley height (Svk) 0.001 μm, protrusion valley space volume (Vvv) 0.000 ml / M ² , core space volume (Vvc) 0.001 ml / m ² , core volume (Vmc) 0.001 ml / m ² , maximum height (Sz) 0.08 μm, thickness 50 μm) in the vertical direction 20 cm It was cut out in a horizontal direction of 8 cm and set on a movable table so that the untreated surface, which had not been subjected to surface modification treatment such as corona discharge, was on the upper surface without wrinkles.

In this state, the dynamic friction force coefficient D1 at 5.56 gf / cm ² pressure measured by superimposing the surface of the skin layer of the test film and the biaxially stretched polyester film is set to a table speed of 100 mm / min and a vertical load. The measurement was performed at 50 gf (pressure conversion value 5.56 gf / cm ² ), displacement amount of 60 mm or more (one-way movement), data sampling speed of 50 ms, measurement temperature of 23 ° C., and measurement humidity of 50% RH. From the values obtained in each of the three measurements, the dynamic friction coefficient D1 (the average value between the displacement amounts of 1 to 60 mm) was extracted. The results are shown in Table 1.

Further, the dynamic friction force D2 at a pressure of 33.33 gf / cm ² measured by superimposing the surface of the skin layer of the test film and the biaxially stretched polyester film is measured at a table speed of 100 mm / min and a vertical load of 300 gf (pressure). Converted value 33.33 gf / cm ² ), displacement amount 60 mm or more (one-way movement), data sampling speed every 50 ms, measurement temperature 23 ° C., measurement humidity 50% RH. The dynamic friction force D2 (mean value between displacements 1 to 60 mm) was extracted from the values obtained in each of the three measurements. The results are shown in Table 1.

[Evaluation of winding deviation of the winding body]
A base film having a pressure-sensitive adhesive layer (580 mm width × 300 m, non-silicone PET separator film, pressure-sensitive adhesive layer: epoxy-based pressure-sensitive adhesive (thermosetting resin)) was prepared. The base film and each laminated film are placed in contact with each other so that the skin layer of each laminated film (slitted to a width of 580 mm) prepared in Examples and Comparative Examples is in contact with the pressure-sensitive adhesive layer of the base film. The laminate was prepared by laminating, and this was used as an evaluation sample. The evaluation sample was wound around a winding core (length 620 mm, diameter 92.5 mm) at a speed of 50 m / min to form a winding body. Next, the wound body is packed in a cardboard box, and after a vibration test (level 3) according to the method specified in JIS-Z0232, the unevenness difference of the film roll end face is set to "excellent: A +" and "good: A". , "Medium: B" and "Inferior: C" were evaluated on a four-point scale, and those with "Medium: B" or higher were regarded as acceptable and evaluated according to the following criteria. The results are shown in Table 1.
A +: The unevenness difference of the film roll end face is 0 mm or more and 1.0 mm or less A: The unevenness difference of the film roll end face is 1.0 mm or more and 3.0 mm or less B: The unevenness difference of the film roll end face is 3.0 mm or more and 5.0 mm or less C : The difference in unevenness on the end face of the film roll exceeds 5.0 mm

[Roll stain evaluation]
For stains on the ethylene component on the roll surface, clean the vertically stretched roll before the start of film formation, visually observe the stain state 1 hour after the start of film formation, and check the difference in the state of the surface of the vertically stretched roll. Evaluation was made on a four-point scale of "A +", "good: A", "normal: B", and "poor: C". The results are shown in Table 1.
A +: Same as before film formation A: Almost no stain B: Very slight stain can be confirmed C: White turbid stain can be clearly confirmed

Claims (5)

A core layer made of the composition (B) containing homopolypropylene (b1),
A composition (A) formed on at least one side of the core layer and containing a propylene-based elastomer (a1), an ethylene / propylene block copolymer (a2), and an ethylene / propylene random copolymer (a3). A skin layer consisting of
Equipped with
The composition (A) has a loss tangent tan δ of 0.06 or more at a vibration frequency of 1 Hz and a temperature of 20 ° C.
The composition (A) is a laminated film having a total content of ethylene and butene of 8.0% by mass or more. The laminated film according to claim 1, wherein the composition (A) has an ethylene content of 35.0% by mass or less. The composition (A) has a content of the propylene-based elastomer (a1) of 5 to 65 parts by mass and a content of the ethylene / propylene block copolymer (a2) of 30 to 90 parts by mass. The laminated film according to claim 1 or 2, wherein the ethylene / propylene random copolymer (a3) has a content of 5 to 65 parts by mass. The laminated film according to any one of claims 1 to 3, which is used as a protective film for an adhesive layer of a build-up film. A wound body obtained by winding a build-up film containing the laminated film according to any one of claims 1 to 3.