WO2017125810A1 - Release film - Google Patents

Abstract

The present invention provides a film that has excellent releasability, i.e. the force for releasing the film is light, and is provided with both film surface smoothness and film strength. Specifically, the present invention pertains to a release film in which a base layer, an intermediate layer formed upon at least one surface of the base layer, and an outermost layer formed upon the intermediate layer are laminated, wherein: the intermediate layer includes at least one resin selected from the group consisting of a polyolefin resin B1 having a carboxyl group and a polyolefin resin B2 having a hydroxyl group; the outermost layer includes a resin component as the main component; and said resin component includes a structural unit derived from 4-methylpentene-1.

Description

Release film

The present application includes Japanese Patent Application No. 2006-009802 (Application Date: January 21, 2016), Japanese Patent Application No. 2006-144146 (Application Date: July 22, 2016), and Japanese Patent Application No. 2006- No. 256660 (filing date: December 28, 2016), the contents of which are hereby incorporated by reference in their entirety.

The present invention relates to a film having excellent peelability. In particular, the present invention relates to a peeling film or the like used in, for example, a manufacturing process of an electronic component or an electronic substrate or a manufacturing process of a thermosetting resin member such as a fiber reinforced plastic in the medical field and the industrial field. More specifically, the present invention relates to a release film, a release liner or a separator film used for a surface protective film, an adhesive tape, etc., a process (dicing, die bonding, back grinding) tape separator used in manufacturing semiconductor products, a ceramic capacitor. The present invention relates to a peelable film that is particularly useful as a carrier for forming an unfired sheet during production, a carrier during production of a composite material, a separator film for a protective material, and the like.

Polypropylene film is excellent in light weight, thermal stability and mechanical properties, and is widely used as an industrial material film including packaging. In particular, in recent years, polypropylene film has been used as a non-silicone mold release material by utilizing its low surface energy, as a manufacturing process for electronic components or electronic substrates, or as a manufacturing process for thermosetting resin members such as fiber-reinforced plastics. Widely used in protective materials or mold release materials used in

As such a polypropylene film, for example, a film containing a polypropylene resin and an amorphous α-olefin copolymer elastomer has been proposed (Patent Document 1).
Moreover, the polypropylene film which consists of a polypropylene resin composition containing a polymethylpentene polymer is known (patent document 2).
Patent Document 3 discloses heat resistance and electricity obtained by using as a coating agent a composition containing a copolymer containing a structural unit derived from 4-methyl-1-pentene and a structural unit derived from olefin. A film having excellent insulating properties is described.

Japanese Unexamined Patent Publication No. 2010-184990 Japanese Unexamined Patent Publication No. 2008-189795 Japanese Unexamined Patent Publication No. 2013-227421

However, the film described in Patent Document 1 has insufficient peelability. Moreover, in the film of patent document 2 made aiming at the improvement of the peelability of a film, when the content of polymethylpentene is increased, the compatibility range of polymethylpentene is exceeded, so that rough irregularities are formed on the surface. There arises a problem that a film that can withstand practical use cannot be obtained. Moreover, the film described in Patent Document 3 does not have sufficient strength for use as a release film or the like, and the smoothness may not be sufficient.

Here, the release film is a film that is stored, distributed, etc. in a state of being attached to an adherend surface such as an adhesive surface of the surface protection film, and is peeled off from the adherend surface when using the surface protection film or the like. It is. When peeling a release film from an adhesion surface such as an adhesive surface of a surface protective film, if the strength of the film is not sufficient, a part of the release film may move to the adhesion surface. Moreover, when the smoothness of a peeling film is low, the surface shape of a peeling film may be transcribe | transferred to a to-be-adhered surface. In these cases, when pasting and using the surface protective film having the adherend surface on another surface, it may become a problem that a part of the transferred release film further moves to another surface, Due to the shape of the release film transferred to the adherend surface, the adhesiveness of the surface protective film or the like may be reduced.

Therefore, there is still a need for a film that has good peelability such as a light peel force, and has both film surface smoothness and film strength.

An object of the present invention is to provide a film having good peelability with a light peel force, and having both film surface smoothness and film strength.

In order to solve the above-mentioned problems, the present inventors have studied in detail about the peelable film, and have completed the present invention.

That is, the present invention includes the following preferred embodiments.
[1] A peelable film formed by laminating a base layer, an intermediate layer formed on at least one surface of the base layer, and an outermost layer formed on the intermediate layer,
The intermediate layer contains at least one selected from the group consisting of a polyolefin resin B1 having a carboxyl group and a polyolefin resin B2 having a hydroxyl group,
The outermost layer contains a resin component as a main component, and the resin component contains a structural unit derived from 4-methylpentene-1.
[2] The peelable film according to [1], wherein the resin component includes (1) 4-methylpentene-1 polymer A.
[3] The resin component includes (1) 4-methylpentene-1 polymer A and (2) olefin resin A ′ other than 4-methylpentene-1 polymer A. 2].
[4] The T-peel peeling force (1000 mm / min) to the polyester adhesive tape after standing for 1 hour at 23 ° C. and 50% humidity on the film surface on the outermost layer side is 0.1 to 1.0 N / 25 mm The peelable film according to any one of [1] to [3].
[5] The peelable film according to any one of [1] to [4], wherein the polymer A has a melting point in the range of 80 ° C to 240 ° C.
[6] The peelable film according to any one of [1] to [5], wherein the polymer A has a melting point in the range of 100 ° C. or higher and lower than 160 ° C.
[7] The peelable film according to any one of [1] to [6], wherein the outermost layer has a thickness of 0.1 to 3.0 μm.
[8] The peelable film according to any one of [1] to [7], wherein the resin component constituting the intermediate layer contains a structural unit derived from styrene.
[9] The peelable film according to any one of [1] to [8], wherein the polyolefin resin B1 is a polyolefin obtained by graft copolymerization of maleic acid and / or maleic anhydride.
[10] The peelable film according to any one of [1] to [9], wherein the polyolefin resin B2 is a polyolefin obtained by graft copolymerization of a hydroxyl group-containing (meth) acrylic acid ester and / or a hydroxyl group-containing vinyl ether. .
[11] The peelable film according to any one of [1] to [10], wherein the intermediate layer has a thickness of 0.04 to 1.5 μm.
[12] Any of the above [1] to [11], wherein the protruding peak height (Rpk) in the load curve obtained from the roughness curve of the film surface on the outermost layer side is 0.005 to 0.200 μm. The peelable film described in 1.
[13] A base material layer used as a surface protective film, an adhesive tape release film, a process tape separator or a carrier, an intermediate layer formed on at least one surface of the base material layer, and formed on the intermediate layer The use of a peelable film in which the outermost layer made is laminated,
The intermediate layer contains at least one selected from the group consisting of a polyolefin resin B1 having a carboxyl group and a polyolefin resin B2 having a hydroxyl group,
The outermost layer contains a resin component as a main component, and the resin component contains a structural unit derived from 4-methylpentene-1.
[14] At least a peelable film in which a base material layer and an outermost layer are laminated in order,
The outermost layer contains a resin component as a main component, the specific gravity of the resin component is 1.15 g · cm ⁻³ or less, and the glass transition temperature of the resin component is −10 to 75 ° C.
[15] The peelable film according to [14], wherein an intermediate layer is formed between the base material layer and the outermost layer.
[16] The peelable film according to [15], wherein the intermediate layer contains at least one selected from the group consisting of a polyolefin resin B1 having a carboxyl group and a polyolefin resin B2 having a hydroxyl group.
[17] The peelable film according to [16], wherein the polyolefin resin B1 is a polyolefin obtained by graft copolymerization of maleic acid and / or maleic anhydride.
[18] The peelable film according to [16] or [17], wherein the polyolefin resin B2 is a polyolefin obtained by graft copolymerization of a hydroxyl group-containing (meth) acrylic acid ester and / or a hydroxyl group-containing vinyl ether.
[19] The peelable film according to any one of [14] to [18], wherein the resin component contained as a main component of the outermost layer includes a structural unit derived from 4-methylpentene-1.
[20] The peelable film according to any one of [14] to [19], wherein the resin component contained as a main component of the outermost layer comprises (1) a 4-methylpentene-1 polymer A. .
[21] The resin component contained as a main component of the outermost layer includes (1) 4-methylpentene-1 polymer A and (2) olefin resin A other than 4-methylpentene-1 polymer A. The peelable film according to any one of the above [14] to [20].
[22] The above-mentioned [14] to [21], wherein the T-peel peeling force (1000 mm / min) to the polyester adhesive tape on the film surface on the outermost layer side is 0.1 to 1.0 N / 25 mm The peelable film described in 1.
[23] The peelable film according to any one of [20] to [22], wherein the polymer A has a melting point in the range of 80 ° C to 240 ° C.
[24] The peelable film according to any one of [14] to [23], wherein the outermost layer has a thickness of 0.1 to 3.0 μm.
[25] The peelable film according to any one of [15] to [24], wherein the intermediate layer has a thickness of 0.04 to 1.5 μm.
[26] Any of the above [14] to [25], wherein the protruding peak height (Rpk) in the load curve obtained from the roughness curve of the film surface on the outermost layer side is 0.005 to 0.04 μm. The peelable film described in 1.
[27] The peelable film according to any one of [14] to [26], which is used for applications having a peel rate of 1000 mm / min or more.
[28] Use of a peelable film in which at least a base material layer and an outermost layer are laminated in order, used as a surface protective film, an adhesive tape release film, a process tape separator or a carrier,
The outermost layer contains a resin component as a main component, the specific gravity of the resin component is 1.15 g · cm ⁻³ or less, and the glass transition temperature of the resin component is −10 to 75 ° C. use.

The peelable film of the present invention has a good peelability such as a light peel force, is excellent in the smoothness of the film surface, and is excellent in the surface strength of the film. Therefore, it is particularly suitable as a release film or the like used in a manufacturing process of an electronic component or an electronic substrate or a manufacturing process of a thermosetting resin member such as a fiber reinforced plastic.

1 is a cross-sectional view schematically showing a peelable film in Examples 1 to 14. FIG.

<First peelable film of the present invention>
The first peelable film of the present invention (hereinafter sometimes simply referred to as “the peelable film of the present invention”) includes a base material layer and an intermediate layer formed on at least one surface of the base material layer. A peelable film in which the outermost layer formed on the intermediate layer is laminated, wherein the intermediate layer is at least selected from the group consisting of a polyolefin resin B1 having a carboxyl group and a polyolefin resin B2 having a hydroxyl group 1 type is contained, the said outermost layer contains a resin component as a main component, and the said resin component is a peelable film containing the structural unit derived from 4-methylpentene-1.
The peelable film of the present invention has (1) good peelability (that is, an object (adhered body) is attached to the outermost layer of the peelable film, and then the outermost layer and the object are bonded. In the case of peeling between the two, the peel strength between the outermost layer and the object is low (the property that the peel strength is low) (2) excellent film surface smoothness, And (3) excellent surface strength of the film. Here, regarding the surface strength of the excellent film (3), the object to be pasted is any one of (a) a polyester tape with an acrylic adhesive, and (b) a polyester tape with a rubber adhesive, for example. Also has excellent film surface strength.
Since the peelable film of the present invention has the above effects (1) to (3), the peelable film of the present invention is a process for producing an electronic component or an electronic substrate, or a thermosetting resin member such as a fiber reinforced plastic. It is suitably used as a release film used in the manufacturing process of
The first peelable film of the present invention is a film in which a base material layer, an intermediate layer formed on at least one surface of the base material layer, and an outermost layer formed on the intermediate layer are laminated. is there.
In the present invention and the present specification, the “main component” means a component having the highest content in all components contained in the target layer, and all components contained in the target layer On the other hand, it is preferably a component occupying 50% by mass or more, more preferably a component occupying 70% by mass or more, further preferably a component occupying 90% by mass or more, and even more preferably 95% by mass or more. It is a component, particularly preferably a component occupying 98% by mass or more, and most preferably a component occupying 99% by mass or more.
“/” Described in the unit of each physical property in the present invention and the present specification means “÷”.
In the present invention and the present specification, for example, “X and / or Y” means “at least one selected from the group consisting of X and Y”.

[Base material layer]
The peelable film of the present invention has a base material layer. The material of the base material layer is not particularly limited, but it is preferable that the resin component is a main component. Examples of the resin component that is the main component of the base material layer include, for example, polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polypropylene terephthalate, polypropylene naphthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene, and polypropylene. And polyolefin resins such as polystyrene resins, acetyl cellulose resins such as triacetyl cellulose, acrylic resins such as polymethyl methacrylate, polyurethane resins, polycarbonate resins, polyamide resins, and polyvinyl chloride resins. A base material layer may contain only 1 type of the said resin, and may contain it in combination of 2 or more type. The base material layer in the peelable film of the present invention may be a layer containing a resin selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate, polypropylene, and polystyrene from the viewpoint of processing suitability of the intermediate layer and the outermost layer. Preferably, in a drying step after coating the outermost layer forming composition for forming the outermost layer, a layer containing a polyethylene terephthalate resin from the viewpoint of heat resistance that hardly causes wrinkles or slack in the film. More preferably.

The base material layer may be a layer formed from any of an unstretched film, a uniaxially stretched film, or a biaxially stretched film. From the viewpoint of processing suitability, transparency and dimensional stability, the base material layer is preferably a layer formed from a biaxially stretched film.

The thickness of the base material layer is preferably 15 μm or more, more preferably 20 μm or more, from the viewpoint of proper processing. The thickness of the base material layer is preferably 125 μm or less, more preferably 50 μm or less, from the viewpoint of handling properties when using the product. The thickness of the base material layer is measured according to JIS C-2151 using a micrometer (JIS B-7502).

For the purpose of improving the adhesion between the base material layer and an intermediate layer described later, one or both surfaces of the base material layer may be subjected to a surface treatment as desired. Examples of the surface treatment include roughening treatment such as sand blast treatment or solvent treatment, corona discharge treatment, plasma treatment, chromic acid treatment, flame treatment, hot air treatment, or surface oxidation treatment such as ozone / ultraviolet irradiation treatment. .

[Middle layer]
The peelable film of the present invention has an intermediate layer formed on at least one surface of the base material layer. The intermediate layer is a layer for enhancing the adhesion between the base material layer and the outermost layer described later and enhancing the strength of the film, and is selected from the group consisting of a polyolefin resin B1 having a carboxyl group and a polyolefin resin B2 having a hydroxyl group. Containing at least one kind.

[Polyolefin resin B1 having a carboxyl group and polyolefin resin B2 having a hydroxyl group]
The polyolefin resin B1 having a carboxyl group preferably has an acid value of 10 to 100 mgKOH / g, more preferably 30 to 80 mgKOH, and still more preferably 40 to 60 mgKOH, from the viewpoint of adhesion between the base material layer and the outermost layer. The acid value here is a value measured by a method based on JIS0070 (neutralization titration method).
The polyolefin resin B2 having a hydroxyl group preferably has a hydroxyl value of 10 to 100 mgKOH / g, more preferably 30 to 80 mgKOH, and still more preferably 40 to 60 mgKOH, from the viewpoint of adhesion between the base material layer and the outermost layer. The hydroxyl value here is a value measured by a method based on JIS0070 (neutralization titration method).

The polyolefin resin B1 having a carboxyl group and the polyolefin resin B2 having a hydroxyl group can be produced, for example, by introducing a carboxyl group or a hydroxyl group into the polyolefin resin.

As the polyolefin resin, a homopolymer of at least one monomer selected from the group consisting of ethylene and an α-olefin having 3 to 20 carbon atoms, or a copolymer of two or more monomers selected from these And a copolymer of at least one monomer selected from the group consisting of ethylene and an α-olefin having 3 to 20 carbon atoms and another polymerizable monomer. Examples of the olefin include α-olefins and diolefins such as butadiene. Examples of the polyolefin resin include polyethylene such as high density polyethylene, low density polyethylene and linear low density polyethylene resin, polypropylene, polyisobutylene, poly (1-butene), poly-4-methylpentene, polyvinylcyclohexane, polystyrene, poly ( p-methylstyrene), poly (α-methylstyrene), ethylene / propylene block copolymer, ethylene / propylene random copolymer, propylene / 1-butene block copolymer, propylene / 1-butene random copolymer, Examples include ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / methyl methacrylate copolymer, ethylene / vinyl acetate / methyl methacrylate, ethylene / butadiene / styrene copolymer, and ionomer resin.

The polyolefin resin is composed of propylene, ethylene, and 4 to 20 carbon atoms (preferably 4 to 12 carbon atoms) from the viewpoint of solubility in a solvent when obtaining a coating liquid and film formability when obtaining a coating film. And a copolymer with at least one monomer selected from the group consisting of α-olefins. Here, as the α-olefin having 4 to 20 carbon atoms, specifically, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-tetradecene, 1-octadecene, etc. Is mentioned. In this embodiment, the polyolefin resin may be a copolymer of propylene and one monomer selected from the group consisting of ethylene and an α-olefin having 4 to 20 carbon atoms, or propylene and ethylene. And a copolymer with two or more monomers selected from the group consisting of α-olefins having 4 to 20 carbon atoms. The polyolefin resin is more preferably a resin obtained by copolymerizing at least propylene and ethylene or 1-butene from the viewpoint of solubility in a solvent when obtaining a coating liquid.

In one embodiment of the present invention, the polyolefin resin is preferably a resin obtained by copolymerizing at least propylene and ethylene. In this embodiment, the content of the structural unit derived from propylene in the polyolefin resin is preferably 50 to 75 mol%, more preferably 60 to 70 mol% based on all the structural units constituting the polyolefin resin. . Further, the content of the structural unit derived from ethylene in the polyolefin resin is preferably 25 to 50 mol%, more preferably 30 to 40 mol%, based on the total structural units constituting the polyolefin resin. The polyolefin resin may contain a constituent unit derived from an α-olefin and / or other polymerizable monomer other than the constituent unit derived from propylene and ethylene, and the content thereof is all the constituent units constituting the polyolefin resin. Is preferably 40 mol% or less, and more preferably 30 mol% or less.
In this embodiment, the degree of crystallinity measured by X-ray diffraction of the polyolefin resin is preferably 2 to 20% from the viewpoint of solubility in a solvent and film formability as a coating film when obtaining a coating liquid. Yes, more preferably 5 to 18%.
In this embodiment, the polyolefin resin may be a block copolymer or a random copolymer. From the viewpoint of solubility in a solvent when obtaining a coating liquid and film forming properties when obtaining a coating film, the polyolefin resin is preferably a random copolymer.

In another embodiment of the present invention, the polyolefin resin is preferably a resin obtained by copolymerizing at least propylene and 1-butene. In this embodiment, the content of the structural unit derived from propylene in the polyolefin resin is preferably 50 to 95 mol%, more preferably 60 to 93 mol%, based on all the structural units constituting the polyolefin resin. More preferably, it is 70 to 90 mol%. Further, the content of the structural unit derived from 1-butene in the polyolefin resin is preferably 5 to 50 mol%, more preferably 7 to 40 mol% based on all the structural units constituting the polyolefin resin. More preferably, it is 10 to 30 mol%. In addition to the structural units derived from propylene and 1-butene, the polyolefin resin may contain structural units derived from ethylene, other α-olefins and / or other polymerizable monomers. Preferably it is 10 mol% or less based on all the structural units which comprise resin, More preferably, it is 5 mol% or less.

In one embodiment of the present invention in which the polyolefin resin is a resin obtained by copolymerizing at least propylene and 1-butene, the intrinsic viscosity [η] of the polyolefin resin is preferably 0.1 to 12 dl / g, more preferably 0.8. 5 to 12 dl / g, more preferably 1 to 12 dl / g. It is preferable for the intrinsic viscosity [η] of the polyolefin resin to be in the above range since the coating suitability of the coating liquid and the film formability of the coating film are good.
Here, the intrinsic viscosity [η] is measured at 135 ° C. using decalin as a solvent. Specifically, about 20 mg of the copolymer is dissolved in 15 ml of decalin, and the specific viscosity ηsp is measured in an oil bath at 135 ° C. After adding 5 ml of decalin solvent to the decalin solution and diluting, the specific viscosity ηsp is measured in the same manner, and the value of ηsp / C can be obtained as the limiting viscosity by extrapolating the concentration (C) to 0. .

In this embodiment, the molecular weight distribution (Mw / Mn) determined by gel permeation chromatography (GPC) of the polyolefin resin is preferably 3 or less, more preferably 2.0 to 3.0, and even more preferably 2.0 to 2.5. It is preferable for the molecular weight distribution (Mw / Mn) of the polyolefin resin to be in the above range since the film formability of the coating film and the stability of the coating liquid are good. The molecular weight distribution (Mw / Mn) is calculated as the ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) measured by gel permeation chromatography (GPC) method. The GPC apparatus used in the GPC method is not particularly limited, and is a commercially available high-temperature GPC measuring instrument capable of analyzing the molecular weight of polyolefins, for example, a high-temperature GPC measuring instrument with a built-in differential refractometer (RI) manufactured by Tosoh Corporation. HLC-8121GPCHT or the like can be used. In this case, for example, a GPC column manufactured by Tosoh Corporation and three connected TSKgelGMHHR-H (20) HT is used, the column temperature is set to 140 ° C., trichlorobenzene is used as an eluent, Measured at 1.0 ml / min. 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.

In this embodiment, the melting point (T _m ) of the polyolefin resin measured by differential scanning calorimetry (DSC) is preferably 60 to 140 ° C., more preferably 70 to 130 ° C. When the melting point T _m of a polyolefin resin is within the above range is preferable because film forming property of the coating film is good. Melting _{the T m} can be determined using a differential scanning calorimeter (e.g., Perkin Elmer, input compensation type DSCDiamondDSC) a. Specifically, about 2 mg of a sample is packed in an aluminum sample holder, and the sample holder packed with the sample is heated from 0 ° C. to 280 ° C. at a rate of 10 ° C./min under a nitrogen flow, and 5% at 280 ° C. Hold for 5 minutes, cool to −50 ° C. at 10 ° C./min, leave at −50 ° C. for 5 minutes, and then determine melting point T _m as the endothermic peak when the temperature is raised again to 280 ° C. at 10 ° C./min. be able to. When a plurality of peaks are detected, the peak detected on the highest temperature side is adopted as the melting point.

In this embodiment, the polyolefin resin may be a block copolymer or a random copolymer. From the viewpoint of solubility in a solvent when obtaining a coating liquid and film forming properties when obtaining a coating film, the polyolefin resin is preferably a random copolymer.

The polyolefin resin B1 having a carboxyl group can be produced, for example, by introducing a carboxyl group into the polyolefin resin. Introduction of a carboxyl group is achieved, for example, by graft copolymerization of a polyolefin resin and at least one monomer selected from the group consisting of an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, and derivatives thereof. . These monomers can be used alone or in combination of two or more for copolymerization with a polyolefin resin. The monomer is preferably graft copolymerized in an amount of 0.1 to 15 parts by mass, more preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the polyolefin resin to be graft copolymerized. Here, it is preferable that the amount of the monomer is not less than the above lower limit value, because it is easy to improve the adhesion of the intermediate layer to the base layer and the outermost layer described later, and if the amount of the monomer is not more than the above upper limit value, It is preferable because the brittleness of the layer does not increase and the intermediate layer is less prone to cohesive peeling.

Examples of the unsaturated carboxylic acid, unsaturated carboxylic acid anhydride and derivatives thereof include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid and fumaric acid, anhydrides of the unsaturated carboxylic acid, and the unsaturated carboxylic acid. Examples thereof include saturated carboxylic acids or derivatives of the unsaturated carboxylic anhydrides (for example, acid halides, amides, imides or esters). Specifically, as unsaturated carboxylic acid, unsaturated carboxylic acid anhydride and derivatives thereof, maleic anhydride, itaconic anhydride, dimethyl maleate, monomethyl maleate, diethyl maleate, diethyl fumarate, dimethyl itaconate, And diethyl citraconic acid. The unsaturated carboxylic acid, unsaturated carboxylic acid anhydride, and derivatives thereof are preferably maleic acid and / or maleic anhydride from the viewpoint of ease of production.

As a method for introducing a carboxyl group into a polyolefin resin, for example,
-To a polyolefin resin solution obtained by dissolving a polyolefin resin in an organic solvent, at least one monomer selected from the group consisting of an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, and derivatives thereof, and a radical polymerization initiator. Adding, and heating and stirring the resulting mixture to cause a graft copolymerization reaction,
-To a melt obtained by heating and melting a polyolefin resin, at least one monomer selected from the group consisting of an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, and derivatives thereof and a radical polymerization initiator are added, A method of stirring and graft copolymerizing the obtained mixture,
Extruder is a mixture obtained by previously mixing a polyolefin resin, at least one monomer selected from the group consisting of unsaturated carboxylic acids, unsaturated carboxylic acid anhydrides and derivatives thereof, and a radical polymerization initiator A method of graft copolymerization while heating and kneading, or at least one monomer selected from the group consisting of unsaturated carboxylic acids, unsaturated carboxylic acid anhydrides and derivatives thereof, and a radical polymerization initiator, Examples include a method in which a polyolefin resin is impregnated with a solution obtained by dissolving an organic solvent in an organic solvent, and then heated to the highest temperature at which the polyolefin resin does not dissolve to cause a graft copolymerization reaction.

The radical polymerization initiator used in the above method is not particularly limited as long as it initiates polymerization of a polyolefin resin and the monomer. Examples of such radical polymerization initiators include organic peroxides, organic peresters, and azo compounds. The radical polymerization initiator is preferably an organic peroxide or an organic perester. Examples of the organic peroxide include benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di (peroxybenzoate) hexyne-3,1,4-bis (Tert-Butylperoxyisopropyl) benzene, lauroyl peroxide, etc. are mentioned. Examples of organic peresters include tert-butyl peracetate, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne-3, 2,5-dimethyl-2,5-di (tert-butyl). Peroxide) hexane, tert-butyl benzoate, tert-butyl perphenyl acetate, tert-butyl perisobutyrate, tert-butyl per-sec-octoate, tert-butyl perpivalate, cumyl perpivalate and tert-butyl perdiethyl Examples include acetate.

The radical polymerization initiator is dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne-3,2,5-dimethyl-2,5-di ( Dialkyl peroxides such as tert-butylperoxy) hexane and 1,4-bis (tert-butylperoxyisopropyl) benzene are more preferable from the viewpoint of ease of production.

It is preferable from the viewpoint of ease of production that the radical polymerization initiator is used in an amount of about 0.001 to 10 parts by mass with respect to 100 parts by mass of the polyolefin resin to be graft copolymerized.

The polyolefin resin B1 having a carboxyl group is preferably a polyolefin obtained by graft copolymerization with at least one monomer selected from the group consisting of unsaturated carboxylic acids, unsaturated carboxylic acid anhydrides and derivatives thereof, and more preferably. Is a polyolefin obtained by graft copolymerization of maleic acid and / or maleic anhydride. Polyolefin resins satisfying such requirements are commercially available in solution form. Specifically, Unistor (registered trademark) P-401 (manufactured by Mitsui Chemicals), Unistor (registered trademark) P-802 ( Examples include Mitsui Chemical Co., Ltd., Unistor (registered trademark) P-902 (manufactured by Mitsui Chemicals), and Hardren (registered trademark) NS-2002 (Toyobo Co., Ltd.).

The polyolefin resin B2 having a hydroxyl group can be produced, for example, by introducing a hydroxyl group into the polyolefin resin. Introduction of a hydroxyl group is achieved, for example, by graft copolymerizing the polyolefin resin with at least one monomer selected from the group consisting of a hydroxyl group-containing (meth) acrylic acid ester and a hydroxyl group-containing vinyl ether. These monomers can be used alone or in combination of two or more for copolymerization with the polyolefin resin. The monomer is preferably graft copolymerized in an amount of 0.1 to 15 parts by mass, more preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the polyolefin resin to be graft copolymerized. Here, it is preferable that the amount of the monomer is equal to or more than the above lower limit value because it is easy to improve the adhesion of the intermediate layer to the base layer and the outermost layer described later, and the amount of the monomer is equal to or less than the above upper limit value. This is preferable because the brittleness of the intermediate layer does not increase and the intermediate layer is less likely to be agglomerated.

Examples of the hydroxyl group-containing (meth) acrylic acid ester include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, glycerol (meth) acrylate, lactone-modified hydroxyethyl (meth) acrylate, and (meth) acrylic. Examples include acid polyethylene glycol and (meth) acrylic acid polypropylene glycol. The hydroxyl group-containing (meth) acrylic acid ester monomer is preferably hydroxyethyl (meth) acrylate from the viewpoint of ease of production.
Examples of the hydroxyl group-containing vinyl ether include 2-hydroxyethyl vinyl ether, diethylene glycol monovinyl ether, and 4-hydroxybutyl vinyl ether. The hydroxyl group-containing vinyl ether is preferably 2-hydroxyethyl vinyl ether from the viewpoint of ease of production and film formability of the coating film.

The polyolefin resin B2 having a hydroxyl group is preferably a polyolefin obtained by graft copolymerization of a hydroxyl group-containing (meth) acrylic acid ester and / or a hydroxyl group-containing vinyl ether. Polyolefin resins satisfying such requirements are commercially available in solution form. Specifically, UNISTOL (registered trademark) P-801 (manufactured by Mitsui Chemicals, Inc.) and UNISTOL (registered trademark) P-901 are available. (Mitsui Chemicals, Inc.).

In addition, in the resin component which comprises an intermediate | middle layer, the structural unit derived from styrene may be contained. Such a structural unit derived from styrene may be contained as a structural unit in at least one resin component selected from the group consisting of a polyolefin resin B1 having a carboxyl group and a polyolefin resin B2 having a hydroxyl group. Alternatively, the resin component constituting the intermediate layer may be contained as a resin (polystyrene or styrene polymer) other than the resins B1 and B2. In the former case, that is, when a structural unit derived from styrene is contained in the resin B1 and / or B2, as a method for introducing the structural unit derived from styrene into the resin B1 and / or B2, for example, And styrene as a monomer component to be copolymerized with a polyolefin resin.
Resins containing structural units derived from styrene as described above are commercially available in the form of solutions. Specifically, Aronmelt PPET1303S (manufactured by Toagosei Co., Ltd.), Aronmelt PPET1401SG (manufactured by Toagosei Co., Ltd.), and Aronmelt PPET1505SG (manufactured by Toagosei Co., Ltd.) can be mentioned.
When the structural component derived from styrene is contained in the resin component constituting the intermediate layer, it is easy to increase the heat resistance of the peelable film, and as a result, even after a high temperature treatment of, for example, 110 ° C. or more, light peelability is obtained. It is preferable from the viewpoint of being retained. In particular, the resin component constituting the intermediate layer contains a structural unit derived from styrene, and the outermost layer has a melting point of 100 ° C. or higher and lower than 160 ° C. (more preferably 110 ° C. or higher and 155 ° C. or lower, more preferably When the 4-methylpentene-1 type polymer A that is in the range of 120 ° C. or higher and 140 ° C. or lower is included, the above-described effect is more exhibited, which is more preferable.

At least one resin component selected from the group consisting of a polyolefin resin B1 having a carboxyl group and a polyolefin resin B2 having a hydroxyl group may be partially chlorinated. Chlorination is performed by a known method. Specifically, for example, at least one polymer of the polyolefin resin having a carboxyl group and the polyolefin resin having a hydroxyl group is thermally melted or dissolved in a solvent, and the obtained melt or solution is introduced with chlorine. While being sealed, it is heated at a temperature of 130 ° C. or lower. The temperature is not limited as long as it is within the above range. From the viewpoints of ensuring solubility for facilitating the reaction of the oxidatively modified propylene-containing polymer and suppressing the decrease in molecular weight due to thermal decomposition, the maximum temperature reached during chlorination is preferably 110 to 130 ° C., 115 to 125 ° C is more preferred.
The weight average molecular weight (Mw) of the polyolefin resin B1 having a chlorinated carboxyl group and the polyolefin resin B2 having a hydroxyl group is not limited, but is preferably 3,000 to 100,000. When the weight average molecular weight (Mw) is 3,000 or more, the cohesive force becomes strong and good adhesion to a polypropylene substrate is easily obtained. On the other hand, when the weight average molecular weight (Mw) is 100,000 or less, good adhesion to the base material layer and good solubility in a solvent are easily obtained. A more preferred weight average molecular weight (Mw) is 10,000 to 50,000. The weight average molecular weight (Mw) is measured in the same manner as the method for measuring the molecular weight distribution (Mw / Mn) described above.
The polyolefin resin B1 having a chlorinated carboxyl group and the polyolefin resin B2 having a hydroxyl group satisfying such requirements are commercially available in the form of a solution. Company-made), Hardren (registered trademark) EH-801 (manufactured by Toyobo Co., Ltd.), Supercron (registered trademark) C (Nippon Paper Industries Co., Ltd.), Supercron (registered trademark) 803M (Nippon Paper Industries Co., Ltd.), and Supercron (Registered trademark) 803LT (Nippon Paper Industries Co., Ltd.) can be mentioned.

The weight average molecular weight (Mw) of the polyolefin resin B1 having a carboxyl group and the polyolefin resin B2 having a hydroxyl group is 1 from the viewpoint of easily achieving both the solubility in a solvent and the film formability of a coating film when obtaining a coating liquid. , Preferably from 2,000 to 200,000, more preferably from 1,000 to 50,000. The weight average molecular weight (Mw) is measured in the same manner as the method for measuring the molecular weight distribution (Mw / Mn) described above.

The glass transition temperature (Tg) of the polyolefin resin B1 having a carboxyl group and the polyolefin resin B2 having a hydroxyl group is preferably −5 to 60 ° C., and preferably 0 to 50 ° C. from the viewpoint of the film formability of the coating film. It is more preferable. The glass transition temperature can be measured according to JIS7121.

[Resin that may be contained in the intermediate layer other than the polyolefin resins B1 and B2]
The intermediate layer may include a resin other than the polyolefin resin B1 having a carboxyl group and the polyolefin resin B2 having a hydroxyl group. Examples of such resins include styrene polymers, styrene- (meth) acrylic polymers, acrylonitrile butadiene styrene polymers, vinyl chloride polymers, vinyl acetate polymers, and ethylene-vinyl acetate polymers. Coalescence is mentioned. When the resin is contained, the content thereof is preferably 1 to 70% by mass, more preferably 5 to 50% by mass based on the total amount of the resin constituting the intermediate layer. From the viewpoint of heat resistance that suppresses heavy peeling at a high temperature of the peelable film, the intermediate layer preferably contains a styrene-based polymer. From the viewpoint of adhesion to the outermost layer and the base material layer, the intermediate layer does not contain such a resin, that is, the resin component constituting the intermediate layer is a polyolefin resin B1 having a carboxyl group and a polyolefin resin having a hydroxyl group. Most preferred is a resin selected from the group consisting of B2.

[Action mechanism between intermediate layer and outermost layer]
Although the action mechanism between the intermediate layer of the present invention and the outermost layer described later is not clear, the following action mechanism is presumed.
It originates in the carboxyl group and / or hydroxyl group which at least 1 sort (s) selected from the group which consists of said resin B1 and said resin B2 contained in an intermediate | middle layer, and 4-methylpentene-1 in the resin component contained in a surface layer Interaction occurs with the structural unit (for example, interaction occurs between the carbon atom having the two methyl groups (carbon atom at the 4-position) of the structural unit and the carboxyl group and / or hydroxyl group). Therefore, it is presumed that excellent film strength, good peelability and the like can be obtained. However, the reason (mechanism) that the peelable film of the present invention is excellent in the above effect will be clearly described here as being within the scope of the present invention even if it is different from the above reason (mechanism).

[Method for producing intermediate layer]
The intermediate layer is, for example, at least one selected from the group consisting of a polyolefin resin B1 having a carboxyl group and a polyolefin resin B2 having a hydroxyl group, and optionally a resin other than the polyolefin resins B1 and B2, and at least one solvent. Is applied to at least one surface of the base material layer, and the solvent is removed from the obtained coating layer.

The solvent is not particularly limited as long as it can dissolve the polyolefin resins B1 and B2 and resins other than the polyolefin resins B1 and B2 in the intermediate layer. Examples of such a solvent include organic solvents such as aromatic hydrocarbons such as toluene and xylene, and aliphatic hydrocarbons such as n-heptane and methylcyclohexane. The boiling point of the solvent is preferably 10 to 150 ° C., more preferably 20 to 120 ° C. from the viewpoint of easy handling of the coating liquid and easy production of the peelable film.

The concentration of the resin in the coating liquid (polyolefin resin B1 and / or B2 and the concentration of such resin when the resin other than the polyolefin resin B1 and B2 is included in the intermediate layer) is the stability of the coating liquid. From the viewpoint of coating suitability, the content is preferably 1 to 15% by mass, more preferably 2 to 5% by mass based on the total amount of the coating solution. A coating method is not specifically limited, A conventionally well-known coating method can be used suitably. Examples of the coating method include a method using a blade coater, an air knife coater, a roll coater, a bar coater, a gravure coater, a micro gravure coater, a rod blade coater, a lip coater, a die coater, a curtain coater, or a printing machine.

The method for removing the solvent from the coating layer is not particularly limited as long as the solvent can be volatilized. Note that removing the solvent does not mean that the solvent is completely removed, but also includes removing the solvent to such an extent that a layer is formed. Examples of the method for removing the solvent include a method in which the coating layer is left to dry and a method in which the coating layer is dried by heating. From the viewpoint of easily achieving both solvent removal and substrate deformation prevention, drying at 90 to 110 ° C. is preferable, and drying at 95 to 105 ° C. is more preferable.

The thickness of the intermediate layer is preferably 0.04 μm or more, more preferably 0.1 μm or more, from the viewpoint of easily achieving both film formability and adhesion. The thickness of the intermediate layer is preferably 1.5 μm or less, more preferably 0.5 μm or less, from the viewpoint of the coating suitability of the outermost layer. The thickness of the intermediate layer is measured by a light interference method using a surface / layer cross-sectional shape measuring instrument (for example, “VertScan (registered trademark) 2.0” manufactured by Ryoka System Co., Ltd.).

[Outermost layer]
The peelable film of the present invention has an outermost layer (surface layer) formed on the intermediate layer. The outermost layer is a layer for imparting peelability to the peelable film of the present invention, and is a layer containing a resin component as a main component. The resin component includes a structural unit derived from 4-methylpentene-1 (4-methyl-1-pentene) (hereinafter sometimes referred to as “structural unit derived from 4-methylpentene-1”). Here, the main component means a component having the largest content in the outermost layer. The content of the resin component in the outermost layer is preferably 50% by mass or more, more preferably 70% by mass or more, and more preferably 90% by mass or more with respect to all the components contained in the outermost layer. Is more preferably 95% by mass or more, particularly preferably 98% by mass or more, and most preferably 99% by mass or more. The upper limit of the content of the resin component in the outermost layer is 100% by mass. As will be described later, the outermost layer may contain components other than the resin component (for example, additives).

[Resin contained in the outermost layer]
If the resin component in the outermost layer contains a structural unit derived from 4-methylpentene-1 (hereinafter sometimes simply referred to as “structural part”, “structural unit”, or “structural part”) Well, the content of the structural unit is not limited.
The lower limit of the content of the structural unit derived from 4-methylpentene-1 relative to the resin component in the outermost layer is preferably 1% by mass or more, more preferably 10% by mass or more, and further preferably 20% by mass or more. 30 mass% or more is still more preferable, 50 mass% or more is especially preferable, 70 mass% or more is especially preferable, and 85 mass% or more is the most preferable. Moreover, about the upper limit of content of the structural unit derived from 4-methylpentene-1 with respect to a resin component, 99 mass% or less is preferable, 97 mass% or less is more preferable, 95 mass% or less is more preferable, 94 mass % Or less is particularly preferable, and 93% by mass or less is particularly preferable. Moreover, about the lower limit of content of the structural unit derived from 4-methylpentene-1 with respect to all the components in outermost layer, 1 mass% or more is preferable, 10 mass% or more is more preferable, and 20 mass% or more is further more Preferably, 30% by mass or more is even more preferable, 50% by mass or more is particularly preferable, 70% by mass or more is particularly preferable, and 85% by mass or more is most preferable. Moreover, about the upper limit of content of the structural unit derived from 4-methylpentene-1 with respect to all the components in the outermost layer, 99 mass% or less is preferable, 97 mass% or less is more preferable, 95 mass% or less is further Preferably, 94 mass% or less is especially preferable, and 93 mass% or less is especially preferable.
When the content of the structural unit derived from 4-methyl-1-pentene in the resin component or in the outermost layer is not less than the lower limit value of the above range, it is preferable because the peelability is further improved, and is not more than the above upper limit value. And the solubility in a solvent when obtaining a coating liquid is further improved.

The proportion of the structural unit derived from 4-methylpentene-1 with respect to the resin component in the outermost layer is preferably 54 mol% to 90 mol%, more preferably 70 mol%, from the viewpoint of easily obtaining light peelability. It is 90 mol%, more preferably 75 mol% to 89 mol%, still more preferably 80 mol% to 86 mol%.

In one embodiment, the resin component constituting the outermost layer includes (1) 4-methylpentene-1 polymer A, and in another embodiment (1) 4-methylpentene-1 polymer A and ( 2) An olefin resin A ′ other than the 4-methylpentene-1 polymer A is included. More specifically, the resin component constituting the outermost layer is
(I) When the resin component is (1) 4-methylpentene-1 polymer A,
(II) When the resin component is an olefin resin A ′ other than (1) 4-methylpentene-1 polymer A and (2) 4-methylpentene-1 polymer A,
(III) When the resin component is (1) 4-methylpentene-1 polymer A, and (3) a thermoplastic resin component different from the resin components of (1) and (2), and (IV ) When it is the resin component of (1), (2), and (3), it is classified as such.
That is, with respect to the resin component constituting the outermost layer, any of the above aspects (I) to (IV) is also included in the present invention.

[In the case of (I) above]
The case where the resin component is (1) 4-methylpentene-1 polymer A (in the case of (I) above) will be described. The 4-methylpentene-1 polymer is a polymer containing a structural unit derived from 4-methylpentene-1, and is a 4-methylpentene-1 homopolymer or a copolymer of 4-methylpentene-1. is there. The resin component may contain one kind of 4-methylpentene-1 series polymer as a 4-methylpentene-1 series polymer, or a combination of two or more kinds of 4-methylpentene-1 series polymers. You may contain.

The copolymer of 4-methylpentene-1 is, for example, at least one selected from the group consisting of 4-methylpentene-1 and an α-olefin having 2 to 20 carbon atoms excluding 4-methylpentene-1. Examples include copolymers with seed olefins.
The at least one olefin selected from the group consisting of α-olefins having 2 to 20 carbon atoms excluding 4-methylpentene-1 has 2 to 20 carbon atoms (preferably 2 to 10 carbon atoms). Linear α-olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene and 1-eicosene and the like; and preferably a branched α-olefin having 5 to 20 carbon atoms (more preferably 5 to 10 carbon atoms), such as 3-methyl-1-butene, 3-methyl-1-pentene 3-ethyl-1-pentene, 4,4-dimethyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4-ethyl-1-hexe And 3-ethyl-1-hexene, and the like.

Moreover, in addition to the structural unit derived from 4-methylpentene-1 and the structural unit derived from the olefin, a structural unit derived from another polymerizable monomer may be contained.
Examples of other polymerizable monomers include, for example, cyclopentene, cycloheptene, norbornene, 5-methyl-2-norbornene, and tetracyclododecene, which preferably have 4 to 20 carbon atoms (more preferably 5 to 15 carbon atoms). Cyclic olefins; mono or such as styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o, p-dimethylstyrene, o-ethylstyrene, m-ethylstyrene and p-ethylstyrene Polyalkylstyrene, and vinyl compounds having a cyclic structure such as vinylcyclopentene, vinylcyclohexane and vinylnorbornene; vinyl esters such as vinyl acetate; unsaturated organic acids such as maleic anhydride or derivatives thereof; 1,3-butadiene, etc. Butadiene, isoprene, chloroprene 1,3-pentadiene, etc., preferably 2,3-dimethylbutadiene, 4-methyl-1,3-pentadiene, 1,3-hexadiene, 1,3-octadiene, etc. Preferably conjugated dienes having 4 to 10 carbon atoms; 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,4-octadiene, 1,5-octadiene, 1,6-octadiene, 1,7-octadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, 7-methyl-1,6-octadiene, 4-ethylidene-8-methyl-1,7-nonadiene, 4,8-dimethyl-1,4,8-decatriene (DMDT), dicyclopentadiene, cyclohexadiene, dicyclooctadiene, methylene norbo Nene, 5-vinylnorbornene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropylidene-2-norbornene, 6-chloromethyl-5-isopropyl-2-norbornene, 2,3-di Preferably it has 5 to 20 carbon atoms (more preferably 5 to 10 carbon atoms) such as isopropylidene-5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene and 2-propenyl-2,2-norbornadiene. Non-conjugated polyenes.
Other polymerizable monomers include, for example, functionalized vinyl compounds such as hydroxyl group-containing olefins; halogenated olefins; acrylic acid, propionic acid, 3-butenoic acid, 4-pentenoic acid, 5-hexenoic acid, 6- Unsaturated carboxylic acids such as heptenoic acid, 7-octenoic acid, 8-nonenoic acid and 9-decenoic acid; unsaturated amines such as allylamine, 5-hexenamine and 6-heptenamine; (2,7-octadienyl) succinic acid Unsaturated anhydrides such as anhydrides, pentapropenyl succinic anhydrides, anhydrides of the above unsaturated carboxylic acids; halides of the above unsaturated carboxylic acids; 4-epoxy-1-butene, 5-epoxy-1 -Pentene, 6-epoxy-1-hexene, 7-epoxy-1-heptene, 8-epoxy-1-octene, 9-epoxy-1-no Emissions, unsaturated epoxy compounds such as 10-epoxy-1-decene and 11-epoxy-1-undecene and the like.
Examples of the hydroxyl group-containing olefin include olefin compounds having a hydroxyl group. Such a compound is not particularly limited as long as it is an olefin compound having a hydroxyl group. The olefinic compound having a hydroxyl group is preferably a terminal hydroxylated olefin compound.
Examples of the terminal hydroxylated olefin compound include vinyl alcohol, allyl alcohol, hydroxyl-1-butene, hydroxyl-1-pentene, hydroxyl-1-hexene, hydroxyl-1-octene, hydroxyl-1- Decene, hydroxyl-1-dodecene, hydroxyl-1-tetradecene, hydroxyl-1-hexadecene, hydroxyl-1-octadecene, hydroxyl-1-octodecene and the like preferably have 4 to 20 carbon atoms (more preferably A linear hydroxylated α-olefin having 2 to 10 carbon atoms; hydroxylated 3-methyl-1-butene, hydroxylated 4-methyl-1-pentene, hydroxylated 3-methyl-1-pentene , Hydroxide-3-ethyl-1-pentene, hydroxyl-4,4-dimethyl-1-pentene, hydroxyl-4-methyl-1-hexene, hydroxyl-4,4-dimethyl-1-hexene, water Oxidation Preferably branched hydroxylated α-olefins having 5 to 20 carbon atoms (more preferably 5 to 10 carbon atoms) such as 4-ethyl-1-hexene and hydroxylated 3-ethyl-1-hexene are used. Can be mentioned.
Examples of the halogenated olefin include halogenated-1-butene, halogenated-1-pentene, halogenated-1-hexene, halogenated-1-octene, halogenated-1-decene, and halogenated-1-dodecene. , Halogenated-1-tetradecene, halogenated-1-hexadecene, halogenated-1-octadecene, halogenated-1-eicocene and the like, preferably having 4 to 20 carbon atoms (more preferably 4 to 10 carbon atoms). Linear halogenated α-olefin; halogenated-3-methyl-1-butene, halogenated-4-methyl-1-pentene, halogenated-3-methyl-1-pentene, halogenated-3-ethyl- 1-pentene, halogenated-4,4-dimethyl-1-pentene, halogenated-4-methyl-1-hexene, halogenated-4,4-di Branches having preferably 5 to 20 carbon atoms (more preferably 5 to 10 carbon atoms) such as methyl-1-hexene, halogenated-4-ethyl-1-hexene and halogenated-3-ethyl-1-hexene And halogenated α-olefins.

When the copolymer contains a structural unit derived from another polymerizable monomer, the content of the structural unit is determined in the copolymer A from the viewpoint of solubility in a solvent when obtaining a coating liquid. The total structural unit is 100 mol%, preferably 5 mol% or less, more preferably 3 mol% or less.

Among the above, at least one olefin selected from the group consisting of α-olefins having 2 to 20 carbon atoms excluding 4-methylpentene-1 is ethylene, propylene, 1-butene, 1-pentene, 1 -Hexene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl -1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, vinyl At least one selected from the group consisting of cyclohexane and styrene is preferred.
The at least one olefin selected from the group consisting of α-olefins having 2 to 20 carbon atoms excluding 4-methylpentene-1 is more preferably α-olefins having 2 to 4 carbon atoms (that is, ethylene). And an α-olefin having 3 to 4 carbon atoms), at least one olefin selected from the group consisting of propylene and 1-butene, more preferably propylene.
The copolymer of 4-methylpentene-1 may be a copolymer containing one olefin selected from the group consisting of α-olefins having 2 to 20 carbon atoms excluding 4-methylpentene-1. It may be a copolymer containing two or more olefins. That is, the copolymer of 4-methylpentene-1 may be a binary copolymer, a ternary copolymer, or a quaternary or higher copolymer.

As described above, since the α-olefin having 2 to 20 carbon atoms excluding 4-methylpentene-1 is particularly propylene, a particularly preferred copolymer of 4-methylpentene-1 is 4-methylpentene- 1 is a copolymer of propylene.

The copolymer of 4-methylpentene-1 has 2 to 20 carbon atoms excluding the structural unit derived from 4-methyl-1-pentene and 4-methylpentene-1 within a range not impairing the effects of the present invention. A structural unit other than the structural unit derived from the α-olefin may be included.

The lower limit value of the proportion of structural units derived from 4-methylpentene-1 to the 4-methylpentene-1 copolymer is not particularly limited. The lower limit of the proportion of the structural units is, for example, preferably 1% by mass or more, more preferably 10% by mass or more, further preferably 20% by mass or more, still more preferably 30% by mass or more, and particularly preferably 50% by mass or more. Preferably, 70% by mass or more is particularly preferable, and 90% by mass or more is most preferable. The upper limit of the proportion of the structural units is, for example, preferably 99% by mass or less, more preferably 97% by mass or less, further preferably 95% by mass or less, particularly preferably 94% by mass or less, and 93% by mass or less. It is particularly preferable. The ratio is preferably increased from the viewpoint of easy development of the film releasability, and is preferably decreased from the viewpoint of film moldability and molding temperature.

The ratio of the structural unit derived from 4-methylpentene-1 to the copolymer of 4-methylpentene-1 is preferably 54 mol% to 90 mol%, more preferably 70 mol, from the viewpoint of light release properties. % To 90 mol%, more preferably 75 mol% to 89 mol%, and still more preferably 80 mol% to 86 mol%.

The proportion of structural units derived from at least one olefin selected from the group consisting of α-olefins having 2 to 20 carbon atoms excluding 4-methylpentene-1 in the copolymer of 4-methylpentene-1 is From the viewpoint of film moldability and molding temperature, it is preferably 99% by mass or less, more preferably 90% by mass or less, and still more preferably 80% by mass based on the total structural units constituting the 4-methylpentene-1 polymer. % Or less, still more preferably 70% by mass or less, particularly preferably 50% by mass or less, particularly preferably 30% by mass or less, and most preferably 15% by mass or less. The ratio is preferably 1% by mass or more, more preferably 3% by mass or more, and further preferably 5% by mass from the viewpoint that the release property of the film is easily expressed by the 4-methylpentene-1 polymer. As mentioned above, More preferably, it is 6 mass% or more, Most preferably, it is 7 mass% or more.

A structural unit derived from at least one olefin selected from the group consisting of α-olefins having 2 to 20 carbon atoms excluding the aforementioned 4-methylpentene-1 with respect to the copolymer of 4-methylpentene-1. The ratio is preferably 10 mol% to 46 mol%, more preferably 10 mol% to 30 mol%, still more preferably 11 mol% to 25 mol%, and particularly preferably 14 mol% to 20 mol, from the viewpoint of light release properties. Mol%.

From the viewpoint of light releasability, 4-methylpentene-1 polymer A is a copolymer of 4-methylpentene-1 and propylene, which is a 4-methylpentene-1 copolymer. The proportion of structural units derived from methylpentene-1 is preferably 54 mol% to 90 mol%, more preferably 70 mol% to 90 mol%, more preferably 75 mol% to 89 mol%. The proportion of structural units derived from propylene with respect to the copolymer of 4-methylpentene-1 is preferably 10 mol% to 46 mol%, more preferably 10 mol% It is particularly preferable to use a copolymer of 4-methylpentene-1 in an amount of from 30 to 30 mol%, more preferably from 11 to 25 mol%, particularly preferably from 14 to 20 mol%.

Here, the structural unit derived from 4-methylpentene-1 in the 4-methylpentene-1 series polymer, from the group consisting of α-olefins having 2 to 20 carbon atoms excluding 4-methylpentene-1. Content of the structural unit derived from the selected at least 1 sort (s) of olefin, the structural unit derived from another polymerizable monomer, etc. can be measured by < ¹³ > CNMR, for example. Specifically, using a nuclear magnetic resonance apparatus (for example, high temperature Fourier transform nuclear magnetic resonance apparatus (high temperature FT-NMR), JNM-ECP500, etc., manufactured by JEOL Ltd.), solvent: orthodichlorobenzene / heavy benzene (80 / 20 volume%) mixed solvent, sample (polymer A) concentration: 55 mg / 0.6 mL, measurement temperature: 135 ° C., observation nucleus: ¹³ C (125 MHz), sequence: single pulse proton decoupling, pulse width: 4. 27.50 ppm can be measured as a reference value for chemical shift under the conditions of 7 μs (45 ° pulse), repetition time: 5.5 seconds, and number of integrations of 10,000 times or more.

The melting point of the 4-methylpentene-1 polymer is not limited. From the viewpoint of film moldability and molding temperature, it is preferably 80 to 240 ° C, more preferably 90 to 200 ° C, still more preferably 100 to 190 ° C, still more preferably 100 ° C or more and less than 160 ° C, and particularly preferably 110 ° C. The temperature is 155 ° C. or lower and particularly preferably 120 to 140 ° C. The melting point is measured using a DSC measuring device (for example, an input compensation DSC Diamond DSC manufactured by Perkin Elmer). Specifically, the melting point is raised from 0 ° C. to 280 ° C. at a rate of 10 ° C./min using a sample as described in the examples, held at 280 ° C. for 5 minutes, and kept at 10 ° C./min. After cooling to −50 ° C. and after leaving at −50 ° C. for 5 minutes, it can be measured as an endothermic peak when the temperature is increased again to 280 ° C. at 10 ° C./min. When a plurality of peaks are detected, the peak detected on the highest temperature side is adopted as the melting point. If no clear endothermic peak is observed, the melting point is not observed.
From the viewpoint of light releasable moldability, the melting point of the 4-methylpentene-1 polymer is preferably not observed or 100 to 180 ° C, more preferably not observed or 110 ° C to 160 ° C. .
The melting point of the 4-methylpentene-1 polymer is adjusted to the above range by adjusting the type or constituent ratio of the monomer constituting the 4-methylpentene-1 polymer and / or the regularity of the polymer. can do.

The melt flow rate (MFR) of the 4-methylpentene-1 polymer is not limited. From the viewpoint of film formability, the MFR is preferably 0.1 to 200 g / 10 min, more preferably 1 to 150 g / 10 min, still more preferably 2 to 25 g / 10 min, and particularly preferably 3 to It is 20 g / 10 minutes, and most preferably 5 to 15 g / 10 minutes. According to JIS K7210, the MFR is a 4-methylpentene-1 polymer having a melting point of 220 ° C. or higher, a measurement condition of a temperature of 260 ° C. and a load of 49.03 N, and a 4-methylpentene-1 polymer having a melting point of less than 220 ° C. The coalescence is a value measured under measurement conditions of a temperature of 230 ° C. and a load of 21.18N.
From the viewpoint of fluidity during molding, the MFR is preferably 0.1 to 100 g / 10 minutes, 0.5 to 50 g / 10 minutes, and 0.5 to 30 g / 10 minutes. The MFR is a value measured at 230 ° C. with a load of 2.16 kg according to ASTM D1238.
The MFR of the 4-methylpentene-1 polymer is adjusted to the above range by adjusting the type or composition ratio of the monomer constituting the 4-methylpentene-1 polymer and / or the regularity of the polymer. can do.

The intrinsic viscosity [η] of the 4-methylpentene-1 polymer is preferably 0.5 dl / g or more, more preferably 0.6 dl / g or more as measured in 135 ° C. decalin. The intrinsic viscosity [η] of the polymer is preferably 5.0 dl / g or less, more preferably 4.0 dl / g or less, and further preferably 2.5 dl / g or less. When the intrinsic viscosity [η] of the polymer is not more than the above upper limit value, it is preferable because the coating suitability and film formability of the coating liquid are good, and when it is not less than the above lower limit value, It is preferable because shape stability can be easily improved. The method for measuring the intrinsic viscosity [η] is as described above.
The intrinsic viscosity [η] is preferably 0.5 to 5.0 dl / g, more preferably 0.5 to 4.0 dl / g, from the viewpoint of low film stickiness and ease of extrusion film forming. . The intrinsic viscosity [η] is a value measured by the following method. After dissolving about 20 mg of 4-methylpentene-1 polymer in 25 ml of decalin, the specific viscosity ηsp is measured in an oil bath at 135 ° C. using an Ubbelohde viscometer. After 5 ml of decalin is added to the decalin solution for dilution, the specific viscosity ηsp is measured in the same manner as described above. This dilution operation is further repeated twice, and the value of ηsp / C when the concentration (C) is extrapolated to 0 is obtained as the intrinsic viscosity [η] (unit: dl / g) (see the following formula 1).
[Η] = lim (ηsp / C) (C → 0) Equation 1
The intrinsic viscosity [η] of the polymer can be adjusted by the amount of hydrogen added in the polymerization step when the polymer is produced.

The density of the 4-methylpentene-1-based polymer is preferably 0.8 to 0.9 g · cm ⁻³ , more preferably 0.82 to 0. 0, from the viewpoint of easily improving the heat resistance of the peelable film. a 85 g · ^{cm -3,} more preferably from 0.825 - 0.85 g · ^{cm -3,} even more even more preferably from 0.825 ~ 0.845 g · ^{cm -3,} particularly preferably 0.825 - 0.84 g · cm ⁻³ . The density of the polymer is a value measured according to JISK6268.
The density of the polymer can be adjusted to the above range by adjusting the type or the composition ratio of the monomer constituting the 4-methylpentene-1 polymer.

The weight average molecular weight (Mw) of the 4-methylpentene-1 polymer is preferably 1 × 10 ⁴ to 2 × 10 ⁶ from the viewpoint of film moldability, and is 1 × 10 ⁴ to 1 × 10 ⁶ . More preferably.
The molecular weight distribution (Mw / Mn), which is the ratio of the weight average molecular weight (Mw) and the number average molecular weight (Mn) measured by gel permeation chromatography (GPC) of 4-methylpentene-1 polymer, is peeled off. From the viewpoint of easily improving the transparency, mechanical properties and surface smoothness of the conductive film, it is preferably 1.0 to 3.5, more preferably 1.3 to 3.0, and still more preferably 1.5 to 2.5. is there. The method for measuring the molecular weight distribution (Mw / Mn) is as described above.
The molecular weight distribution (Mw / Mn) is preferably 1.0 to 3.5, more preferably 1.1 to 3.0, from the viewpoint of film stickiness and appearance. The molecular weight distribution (Mw / Mn) is a value calculated by a standard polystyrene conversion method using the following gel permeation chromatography (GPC).
Measuring device: GPC (ALC / GPC 150-C plus type, suggested refractometer detector integrated type, manufactured by Waters)
Column: Two GMH6-HT (manufactured by Tosoh Corporation) and two GMH6-HTL (manufactured by Tosoh Corporation) are connected in series. Eluent: o-dichlorobenzene Column temperature: 140 ° C.
Flow rate: 1.0 mL / min The value of the molecular weight distribution (Mw / Mn) can be adjusted according to the type of olefin polymerization catalyst, particularly a metallocene catalyst described later.

The crystallization temperature (T _c ) of the 4-methylpentene-1-based polymer is preferably 80 to 190 ° C., more preferably 90 to 170 ° C., from the viewpoint of easily improving the moldability of the peelable film. The crystallization temperature of the polymer can be determined from the temperature at the peak apex of the crystallization peak measured by differential scanning calorimetry (DSC) in the same manner as the melting point (T _m ). When a plurality of peaks are detected, the peak detected on the highest temperature side is adopted as the crystallization temperature.
The crystallization temperature of the polymer can be adjusted to the above range by adjusting the type or the composition ratio of the monomer constituting the 4-methylpentene-1 polymer.

The 4-methylpentene-1 polymer can be produced by a conventionally known method. The 4-methylpentene-1 polymer is, for example, a method described in Japanese Unexamined Patent Publication No. 2013-227421 and Japanese Unexamined Patent Publication No. 2013-3205, a synthesis method using a metallocene catalyst, for example, International Publication No. You may manufacture by the method as described in 2005/121192, international publication 2011/055803.
Commercially available products may be used as the 4-methylpentene-1 polymer (or a resin component containing the 4-methylpentene-1 polymer). For example, TPX (registered trademark) MX002 manufactured by Mitsui Chemicals, Inc. , TPX (registered trademark) DX845 and TPX (registered trademark) EP0518, and 4-methylpentene-1-based resins EP1013 and EP1001 manufactured by Mitsui Chemicals, Inc. may be used.
When the 4-methylpentene-1 polymer is a 4-methylpentene-1 copolymer, for example, 4-methylpentene-1 and 4-methylpentene-1 are excluded in the presence of an olefin polymerization catalyst. It can be produced by polymerizing at least one olefin selected from the group consisting of α-olefins having 2 to 20 carbon atoms and optionally other polymerizable monomers. Examples of the olefin polymerization catalyst include a metallocene catalyst and a Ziegler-Natta catalyst, and preferably a metallocene catalyst. Such metallocene catalysts include, for example, International Publication No. 01/53369, International Publication No. 01/27124, Japanese Unexamined Patent Publication No. 3-193396, Japanese Unexamined Patent Publication No. 02-41303, and International Publication No. 06. / 0255540.

[In the case of (II) above]
The case where the resin component is an olefinic resin A ′ other than (1) 4-methylpentene-1 polymer A and (2) 4-methylpentene-1 polymer A will be described (case (II) above). To do.
(1) Type of 4-methylpentene-1 series polymer A, proportion of structural units derived from 4-methylpentene-1, melting point, MFR, intrinsic viscosity, density, molecular weight distribution, crystallization temperature, production method, etc. The details of are the same as those described for the 4-methylpentene-1 polymer A in the case of (I).

The (2) olefin resin A ′ is defined as a resin component different from the (1) 4-methylpentene-1 polymer A. That is, the (2) olefin resin A ′ does not contain a structural unit derived from 4-methyl-1-pentene.

Specific examples of the (2) olefin resin A 'include an ethylene polymer, a propylene polymer, a 1-butene polymer, a cyclic olefin copolymer, and a chlorinated polyolefin. In the present invention, the (2) olefin resin A 'includes elastomers and copolymer rubbers. The (2) olefin resin A ′ may contain one type of olefin resin or a combination of two or more types of olefin resins.

The ethylene-based polymer is a polymer containing a structural unit derived from ethylene, and is an ethylene homopolymer (homopolyethylene) or an ethylene copolymer. The (2) olefin resin A ′ may contain one ethylene polymer as an ethylene polymer, or may contain a combination of two or more ethylene polymers. The proportion of structural units derived from ethylene in the ethylene-based polymer is not particularly limited. From the viewpoint of transparency and mechanical properties of the film, the ratio is preferably 80 mol% or more, more preferably 90 mol% or more, and still more preferably 95 mol% or more, based on the total structural units constituting the ethylene-based polymer. It is. Moreover, the said ratio may be 100 mol% or less. The ethylene polymer includes polyethylene such as low density, medium density, high density, and high pressure method low density. Examples of the ethylene copolymer include an ethylene / α-olefin copolymer.

The propylene-based polymer is a polymer containing a structural unit derived from propylene, and is a propylene homopolymer (homopolypropylene) or a copolymer of propylene. The (2) olefin resin A ′ may contain one type of propylene polymer as a propylene polymer, or may contain a combination of two or more types of propylene polymers. The proportion of structural units derived from propylene in the propylene-based polymer is not particularly limited. From the viewpoint of transparency and mechanical properties of the film, the ratio is preferably 80 mol% or more, more preferably 90 mol% or more, and still more preferably 95 mol% or more, based on all structural units constituting the propylene polymer. It is. Moreover, the said ratio may be 100 mol% or less.

The homopolypropylene is preferably an isotactic polypropylene homopolymer from the viewpoint of stereoregularity. The isotactic mesopentad fraction (mmmm) of isotactic polypropylene is preferably 92% or more, more preferably 93% or more, and still more preferably 94% or more. However, a syndiotactic polypropylene homopolymer may be used as the homopolypropylene.

The isotactic mesopentad fraction (mmmm) is an index of stereoregularity that can be obtained by high-temperature Fourier transform nuclear magnetic resonance apparatus (high-temperature FT-NMR) measurement. Specifically, it can be measured using, for example, a high-temperature Fourier transform nuclear magnetic resonance apparatus (for example, “JNM-ECP500” manufactured by JEOL Ltd.). The observation nucleus is 13C (125 MHz). The measurement method by high-temperature FT-NMR is performed with reference to the method described in, for example, “Japan Analytical Chemistry / Polymer Analysis Research Roundtable, New Edition, Polymer Analysis Handbook, Kinokuniya, 1995, p. 610”. be able to. For example, measurement can be performed using measurement temperature, solvent, measurement mode, pulse width, pulse interval, number of integrations, and shift reference as described in the examples.

The pentad fraction representing the degree of stereoregularity is a combination of pentads (mmmm and “meso (m)”) arranged in the same direction and “Rasemo (r)” arranged in the opposite direction. calculated as a percentage (%) based on the integrated value of the intensity of each signal derived from mrrm and the like. Each signal derived from mmmm, mrrm, etc. can be attributed with reference to, for example, “T. Hayashi et al., Polymer, 29, 138 (1988)”.

Examples of the copolymer of propylene include a copolymer of propylene and at least one olefin selected from the group consisting of ethylene and at least one α-olefin having 3 to 20 carbon atoms. The copolymer may be a random copolymer or a block copolymer. The olefin selected from the group consisting of ethylene and an α-olefin having 3 to 20 carbon atoms is, for example, ethylene, butene, pentene, hexene, etc., and from the viewpoint of film transparency, mechanical properties and molding temperature, ethylene It is preferable that The propylene polymer may be a copolymer containing one kind of olefin selected from the group consisting of ethylene and an α-olefin having 3 to 20 carbon atoms, or a copolymer containing two or more kinds of the above olefins. It may be a polymer. An olefin selected from the group consisting of ethylene and an α-olefin having 3 to 20 carbon atoms is also referred to as an olefin selected from the group consisting of an α-olefin having 2 to 20 carbon atoms.

The copolymerization ratio of the olefin selected from the group consisting of ethylene and an α-olefin having 3 to 20 carbon atoms in the copolymer of propylene is based on the total amount of the propylene polymer from the viewpoint of transparency of the film. It is preferably 5% by mass or less, and more preferably 4% by mass or less.

The melt flow rate (MFR) of the propylene-based polymer contained in the resin component is preferably 0.5 to 25 g / 10 minutes, more preferably 2 to 10 g / 10 minutes, from the viewpoint of moldability. The MFR is a value measured under measurement conditions of a temperature of 230 ° C. and a load of 21.18 N according to JIS K7210.

The content of ash resulting from the polymerization catalyst residue contained in the propylene-based polymer contained in the resin component is preferably as small as possible from the viewpoint of easily reducing fine foreign matter (fish eye), more preferably It is 50 ppm or less, More preferably, it is 40 ppm or less. When the ash content is 50 ppm or less, fine foreign matters and defects are remarkably reduced, and it is easy to reduce contamination of electronic components when the peelable film of the present invention is used for electronic components.

The content of the propylene polymer in the resin component is preferably from 95 to 50% by mass, more preferably from 85 to 50%, based on the total amount of the resin component, from the viewpoint of easily achieving both surface smoothness and releasability of the film. It is 50% by mass, more preferably 80 to 50% by mass. In this case, the content of the 4-methylpentene-1 polymer in the resin component is preferably 5 to 50 based on the total amount of the resin component from the viewpoint of easily satisfying both the surface smoothness and the releasability of the film. The mass is preferably 10 to 45 mass%, more preferably 15 to 40 mass%.

The 1-butene polymer is a polymer containing a structural unit derived from 1-butene, and is a 1-butene homopolymer or a copolymer of 1-butene and another olefin different from 1-butene. is there. Examples of other olefins different from 1-butene include ethylene and α-olefins having 3 to 20 carbon atoms, such as ethylene, propylene, 1-hexene, 1-octene, 1-decene, 1-tetradecene. And 1-octadecene. The 1-butene polymer may contain a structural unit derived from one or more of these other olefins together with a structural unit derived from 1-butene. The 1-butene polymer is a copolymer of 1-butene and ethylene and / or propylene. From the viewpoint of miscibility between the 1-butene polymer and the 4-methylpentene-1 polymer. To preferred. The 1-butene polymer is preferably a copolymer having 30 to 90 mol% of 1-butene-derived structural units based on all structural units of the 1-butene polymer. Such 1-butene polymers are commercially available. Specifically, Tuffmer BL3450 (manufactured by Mitsui Chemicals), Tuffmer BL3450M (manufactured by Mitsui Chemicals), Tuffmer XM7070 (manufactured by Mitsui Chemicals) and the like Can be mentioned.
The resin component may contain one kind of 1-butene polymer as the 1-butene polymer, or may contain two or more kinds of 1-butene polymers in combination.

When the resin component further contains a 1-butene polymer in addition to the propylene polymer and the 4-methylpentene-1 polymer, the propylene polymer and the 4-methylpentene-1 polymer It is preferable because it has an effect of promoting compatibilization and improving interlayer adhesion.

The melt flow rate (MFR) of the 1-butene polymer is preferably 5 to 15 g / 10 minutes, more preferably 6 to 13 g / 10 minutes, from the viewpoint of film formability. The MFR is a value measured under conditions of a temperature of 230 ° C. and a load of 21.18 N according to JIS K7210.

Examples of the cyclic olefin copolymer include cyclic olefins having 3 to 20 carbon atoms, preferably 5 to 15 carbon atoms (for example, cyclopentene, cyclohexene, cycloheptene, norbornene, 5-methyl-2-norbornene, tetracyclododecene and And a copolymer containing a structural unit derived from vinylcyclohexane and the like.

Ratio of structural units derived from 4-methylpentene-1 in the entire resin component (or resin composition constituting the outermost layer) in the case of (II) above, melting point, MFR, intrinsic viscosity, density, molecular weight distribution, crystal About each detail, such as a conversion temperature, it replaces with the 4-methylpentene-1 type polymer A in the case of (I), and it is said that it is set as "the whole resin component (or resin composition which comprises outermost layer)". This is the same as described in (I).

[In the case of (III) above]
The case where the resin component is (1) the 4-methylpentene-1 polymer A, (3) the resin component different from the resin components of (1) and (2) (in the case of (III) above) will be described. To do.
(1) Type of 4-methylpentene-1 series polymer A, proportion of structural units derived from 4-methylpentene-1, melting point, MFR, intrinsic viscosity, density, molecular weight distribution, crystallization temperature, production method, etc. The details of are the same as those described for the 4-methylpentene-1 polymer A in the case of (I).

The thermoplastic resin component different from the (3) resin component, that is, the (1) 4-methylpentene-1 polymer A and the (2) olefin resin A ′, is a thermoplastic polyamide resin; Thermoplastic polyester resin; Thermoplastic vinyl aromatic resin; Thermoplastic polyurethane; Vinyl chloride resin; Vinylidene chloride resin; Acrylic resin; Ethylene / vinyl acetate copolymer; Ethylene / acrylic acid acrylate copolymer; Ethylene / methacrylic acid Acrylate copolymer; ionomer; ethylene-vinyl alcohol copolymer; polyvinyl alcohol; fluororesin polycarbonate; polyacetal; polyphenylene oxide; polyphenylene sulfide polyimide; polyarylate; polysulfone; polyethersulfone; rosin resin; System resin and petroleum resin; and the copolymer rubber, and the like. The resin component (3) may contain one type, or may contain two or more types in combination.

Ratio of structural units derived from 4-methylpentene-1 in the entire resin component (or resin composition constituting the outermost layer) in the case of (III) above, melting point, MFR, intrinsic viscosity, density, molecular weight distribution, crystal About each detail, such as a conversion temperature, it replaces with the 4-methylpentene-1 type polymer A in the case of (I), and it is said that it is set as "the whole resin component (or resin composition which comprises outermost layer)". This is the same as described in (I).

[In the case of (IV) above]
The case where the resin component is the resin component of (1), (2) and (3) (in the case of (IV) above) will be described.
(1) Type of 4-methylpentene-1 series polymer A, proportion of structural units derived from 4-methylpentene-1, melting point, MFR, intrinsic viscosity, density, molecular weight distribution, crystallization temperature, production method, etc. The details of are the same as those described for the 4-methylpentene-1 polymer A in the case of (I).
(2) Types of olefinic resins A ′ other than 4-methylpentene-1 type polymer A (including monomer types and amounts of components when a copolymer is included), MFR, isotactic meso Details of the pentad fraction, ash content, and the like are the same as in the description of the olefin resin A ′ other than (2) 4-methylpentene-1 polymer A in the case of (II).
(3) The details of each of (1) the 4-methylpentene-1 polymer A, the kind of thermoplastic resin component different from the (2) olefin resin A ′, and the like in the case of (III) (3) This is the same as described for the thermoplastic resin component.
Ratio of structural units derived from 4-methylpentene-1 in the entire resin component (or the resin composition constituting the outermost layer) in the case of (IV) above, melting point, MFR, intrinsic viscosity, density, molecular weight distribution, crystal About each detail, such as a conversion temperature, it replaces with the 4-methylpentene-1 type polymer A in the case of (I), and it is said that it is set as "the whole resin component (or resin composition which comprises outermost layer)". This is the same as described in (I).

[Specific resin components constituting the outermost layer [1] to [6]]
Here, specific examples will be described below. Use of the following [1] to [6] as the resin component constituting the outermost layer (or the resin composition constituting the outermost layer) is preferable as an embodiment of the present invention. The following resin components [1] to [6] may be used as occupying all of the resin components constituting the outermost layer, or as part of the resin components constituting the outermost layer. May be used. As the resin component, one or more of the following resin components [1] to [6] may be used in combination.
[1] Structural unit derived from 4-methylpentene-1 (i) 5 to 95 mol%, at least one α selected from α-olefins having 2 to 20 carbon atoms excluding 4-methylpentene-1 -Consists of 5 to 95 mol% of structural units derived from olefin (ii) and 0 to 10 mol% of structural units derived from non-conjugated polyene (iii) (provided that structural units (i), (ii) and (iii) 4-methylpentene-1α-olefin copolymer)
[2] Structural unit derived from 4-methylpentene-1 (i) 33 to 80 mol%, at least one α selected from α-olefins having 2 to 20 carbon atoms excluding 4-methylpentene-1 -Structural unit derived from olefin (ii) 67-20 mol% and structural unit derived from non-conjugated polyene (iii) 0-10 mol% (however, the sum of structural units (i), (ii) and (iii)) 4-methylpentene-1, α-olefin copolymer (A) comprising 50 to 95 parts by weight, and thermoplastics other than the 4-methylpentene-1, α-olefin copolymer 4 to 50 parts by weight of the resin (B) (provided that the total of the copolymer (A) and the thermoplastic resin (B) is 100 parts by weight), 4-methylpentene-1, α-olefin Copolymer composition,
[3] 50 to 98 parts by weight of 4-methylpentene-1 copolymer (AA), crystalline olefin resin (BB) other than 4-methylpentene-1 copolymer (AA) (for example, melting point is 100 ° C. 1 to 49 parts by weight of the α-olefin copolymer (CC) having a melting point of less than 100 ° C. other than 1 to 49 parts by weight and the 4-methylpentene-1 copolymer (AA). 49 parts by weight (provided that the total of (AA), (BB) and (CC) is 100 parts by weight), and the copolymer (AA) has the following requirement (a-1):
(A-1) The structural unit derived from 4-methylpentene-1 is 5 to 95% by weight, and at least one selected from α-olefins having 2 to 20 carbon atoms excluding 4-methylpentene-1 4-methylpentene-1 · which satisfies the structural unit derived from α-olefin of 5 to 95% by weight (provided that the total amount of the structural units in the copolymer (AA) is 100% by weight). α-olefin copolymer composition,
[4] Structural unit derived from 4-methylpentene-1 (i) 5 to 95 mol%, at least one α selected from α-olefins having 2 to 20 carbon atoms excluding 4-methylpentene-1 -Consists of 5 to 95 mol% of structural units derived from olefin (ii) and 0 to 10 mol% of structural units derived from non-conjugated polyene (iii) (provided that structural units (i), (ii) and (iii) 4 to 95 parts by weight of 4-methylpentene-1, α-olefin copolymer, and a thermoplastic resin other than the 4-methylpentene-1, α-olefin copolymer (B 4) to 95 parts by weight (provided that the total of the copolymer and the thermoplastic resin (B) is 100 parts by weight) Polymer composition,
[5] Structural unit (i) derived from 4-methylpentene-1 33 to 80 mol%, at least one α selected from α-olefins having 2 to 20 carbon atoms excluding 4-methylpentene-1 -Structural unit derived from olefin (ii) 67-20 mol% and structural unit derived from non-conjugated polyene (iii) 0-10 mol% (provided that structural units (i), (ii) and (iii) 4-methylpentene-1, α-olefin copolymer (A) 5 to 49 parts by weight and heat other than the 4-methylpentene-1, α-olefin copolymer 4-methylpentene-1 comprising 51 to 95 parts by weight of a plastic resin (B) (provided that the total of the copolymer (A) and the thermoplastic resin (B) is 100 parts by weight)・ Α-Olefin copolymer Narubutsu,
[6] 50 to 96 parts by weight of 4-methylpentene-1 copolymer (AA), crystalline olefin resin (BB) other than 4-methylpentene-1 copolymer (AA) (for example, melting point is 100 ° C. Α-olefin copolymer (CC) having a melting point of less than 100 ° C. other than 2-45 parts by weight of (BB) and 4-methylpentene-1 copolymer (AA) 2 to 45 parts by weight (provided that the total of (AA), (BB) and (CC) is 100 parts by weight),
The copolymer (AA) has the following requirement (c-1):
(C-1) The structural unit derived from 4-methylpentene-1 is 18 to 90% by weight, and at least one selected from α-olefins having 2 to 20 carbon atoms excluding 4-methylpentene-1 The structural unit derived from the α-olefin is 10 to 82% by weight (provided that the total amount of the structural unit in the copolymer (AA) is 100% by weight).
The 4-methylpentene-1 copolymer composition satisfying

Examples of the non-conjugated polyene in [1], [2], [4] and [5] include non-conjugated polyene having 5 to 20 carbon atoms (preferably 5 to 10). 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,4-octadiene, 1,5-octadiene, 1,6-octadiene, 1,7-octadiene, 2-methyl-1, 5-hexadiene, 6-methyl-1,5-heptadiene, 7-methyl-1,6-octadiene, 4-ethylidene-8-methyl-1,7-nonadiene, 4,8-dimethyl-1,4,8- Decatriene, dicyclopentadiene, cyclohexadiene, dicyclooctadiene, methylene norbornene, 5-vinyl norbornene, 5-ethylidene-2-norbornene, 5-methylene-2- Rubornene, 5-vinylidene-2-norbornene, 5-isopropylidene-2-norbornene, 6-chloromethyl-5-isopropenyl-2-norbornene, 2,3-diisopropylidene-5-norbornene, 2-ethylidene-3 -Isopropylidene-5-norbornene, 2-propenyl-2,2-norbornadiene and the like can be mentioned.
As the thermoplastic resin (B) in [2], [4] and [5], for example, (2) the olefin resin A ′, (3) different from the resin components of (1) and (2) above. The thermoplastic resin etc. which were illustrated in the resin component are mentioned.
The crystalline olefin resin in [3] and [6] is, for example, a resin having a melting point of 70 ° C. or higher in a differential scanning calorimeter.
Examples of the α-olefin in [1] to [6] include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-undecene, 1-dodecene, Examples thereof include linear α-olefins having 2 to 20, preferably 2 to 15 and more preferably 2 to 10 carbon atoms such as tetradecene, 1-hexadecene, 1-octadecene and 1-eicocene.

[Production method of outermost layer]
For example, the outermost layer is formed by coating a coating liquid containing a resin component containing 4-methylpentene-1 polymer A and at least one solvent on the intermediate layer, and from the obtained coating layer. Formed by removing the solvent.

The solvent is not particularly limited as long as the resin component containing 4-methylpentene-1 polymer A can be dissolved. Examples of the solvent include organic solvents such as aromatic hydrocarbons such as toluene and xylene, and aliphatic hydrocarbons such as n-heptane and methylcyclohexane. The boiling point of the solvent is preferably 10 to 150 ° C., more preferably 20 to 120 ° C. from the viewpoint of easy handling of the coating liquid and easy production of the peelable film.

The concentration of the resin component containing 4-methylpentene-1 polymer A in the coating solution is 1 to 10% by mass based on the total amount of the coating solution from the viewpoint of the stability of the coating solution and the coating suitability. It is preferably 4 to 7% by mass. The coating method is not specifically limited, The coating method described about the intermediate | middle layer can be used similarly.

As a method for removing the solvent from the coating layer, the method described for the intermediate layer can be similarly used.

The thickness of the outermost layer is preferably 0.1 μm or more, more preferably 0.3 μm or more, and particularly preferably 0.5 μm or more from the viewpoint of easily improving the peelability. The thickness of the outermost layer is preferably 3.0 μm or less, and more preferably 1.5 μm or less, from the viewpoint of coating suitability and ease of production. The thickness of the outermost layer is measured by an optical interference method using a surface / layer cross-sectional shape measuring instrument (for example, “VertScan (registered trademark) 2.0” manufactured by Ryoka System Co., Ltd.).

〔Additive〕
The base material layer, the intermediate layer, and the outermost layer may contain at least one additive as necessary. Examples of additives include stabilizers such as antioxidants, chlorine absorbers, ultraviolet absorbers, lubricants, plasticizers, flame retardants, antistatic agents, colorants, and antiblocking agents. You may add such an additive to a base material layer, an intermediate | middle layer, or an outermost layer within the range which does not impair the effect of this invention. At least one additive may be contained only in any one of the base material layer, the intermediate layer, and the outermost layer, or may be contained in all the base material layer, the intermediate layer, and the outermost layer. Moreover, the base material layer, the intermediate layer, and the outermost layer may contain the same or different additives.

“Antioxidant” has a role as a primary agent formulated for the purpose of suppressing deterioration due to heat and / or oxidation during the production of a peelable film, and the purpose of suppressing deterioration over time when used for a long time. At least as a secondary agent to be blended. Depending on these roles, different types of antioxidants may be used, or one type of antioxidant that plays two roles may be used.
When different types of antioxidants are used, for example, a primary agent intended to prevent deterioration during production such as deterioration in a molding machine, for example, 2,6-di-tert-butyl-p-cresol It is preferable to add about 1,000 to 3,000 ppm of (generic name: BHT) in the composition for obtaining each layer. Most of the antioxidant blended for this purpose is consumed in the molding process and hardly remains in the peelable film. Therefore, generally the remaining amount is less than 100 ppm, which is preferable in that the adherend is hardly contaminated by the antioxidant.
As the secondary agent, a known antioxidant can be used. Examples of such antioxidants include phenol-based, hindered amine-based, phosphite-based, lactone-based, and tocopherol-based thermal stabilizers and antioxidants. Specifically, as such an antioxidant, dibutylhydroxytoluene, pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 1,3,5-trimethyl- Examples include 2,4,6-tris (3,5-di-t-butyl-4hydroxy) benzene and tris (2,4-di-t-butylphenyl) phosphite. More specifically, examples of such antioxidants include Irganox (registered trademark) 1010, Irganox (registered trademark) 1330, and Irgafos (registered trademark) 168, which are antioxidants manufactured by BASF Japan Ltd.
Among them, at least one selected from phenolic antioxidants or a combination thereof, a combination of phenolic and phosphite, a combination of phenolic and lactone, and a phenolic, phosphite and lactone The combination is preferable because it can give the effect of suppressing deterioration over time when the film is used for a long time.
Moreover, you may use phosphorus antioxidant as a secondary agent. Examples of phosphorus antioxidants include tris (2,4-di-t-butylphenyl) phosphite (trade name: Irgafos (registered trademark) 168) and bis (2,4-di-t-butyl-6). -Methylphenyl) ethyl phosphite (trade name: Irgafos (registered trademark) 38) and the like.
The content of the antioxidant as the secondary agent is preferably from 300 ppm to 2,500 ppm, more preferably from 500 ppm to 1500 ppm, based on the total amount of resin contained in each layer. By setting it as 300 ppm or more, it is easy to give the effect which suppresses deterioration with time at the time of using a film for a long period of time, and by setting it as 2500 ppm or less, it is easy to prevent the adherend from being contaminated by an antioxidant.

The “chlorine absorbent” is not particularly limited, and examples thereof include metal soaps such as calcium stearate.

The “ultraviolet absorber” is not particularly limited, and examples thereof include benzotriazole (such as Tinufin 328 manufactured by BASF), benzophenone (such as Cysorb UV-531 manufactured by Cytec), and hydroxybenzoate (such as UV-CHEK-AM-340 manufactured by Ferro). Is mentioned.

The “lubricant” is not particularly limited, and examples thereof include primary amides (such as stearic acid amides), secondary amides (such as N-stearyl stearic acid amides), and ethylene bisamides (N, N′-ethylene bisstearic acid). Amide etc.).

The “plasticizer” is not particularly limited, and examples thereof include a PP random copolymer.

The “flame retardant” is not particularly limited, and examples thereof include halogen compounds, aluminum hydroxide, magnesium hydroxide, phosphates, borates, and antimony oxides.

The “antistatic agent” is not particularly limited, and examples thereof include glycerin monoesters (such as glycerin monostearate) and ethoxylated secondary amines.

The “colorant” is not particularly limited, and examples thereof include cadmium or chromium-containing inorganic compounds and azo or quinacridone organic pigments.

“Anti-blocking agent” is not particularly limited as long as it is added to prevent blocking and exhibits an effect as a nucleating agent. Examples of the anti-blocking agent include silica particles, alumina, (synthetic) zeolite, calcium carbonate, kaolin, talc, mica, zinc oxide, magnesium oxide, quartz, magnesium carbonate, parium sulfate, and titanium dioxide, and polystyrene. , Polyacrylic particles, polymethylmethacrylate (PMMA) particles, crosslinked polyethylene particles, polyester, polyamide, polycarbonate, polyether, polyethersulfone, polyetherimide, polyphenylene sulfide, polyetheretherketone, polyamideimide, (crosslinked) Melamine resin, benzoguanamine resin, urea resin, amino resin, furan resin, epoxy resin, phenol resin, unsaturated polyester resin, vinyl ester resin, diallyl phthalate tree , Polyimide resin, and organic pigments such as fatty acid amides and fatty acid glycerol ester compounds. The anti-blocking agent is preferably a pigment having a particle size of 0.1 μm to 10 μm, and PMMA and silica particles are more preferable because they are excellent in blocking resistance and slipperiness. For example, by including such a pigment in the base material layer, the slipperiness of the front and back surfaces of the base material layer is improved, and blocking can be suppressed.

(Roughening of the peelable film surface)
You may provide the surface of the peelable film of this invention with the fine surface roughness which improves winding suitability in the range which does not have trouble in bonding in the case of using as a peelable film. As a method for giving fine irregularities to the film surface, an embossing method, an etching method, and various known roughening methods can be employed. Among such methods, a roughening method using β crystals that do not require the incorporation of impurities is preferable. The production rate of β crystals can be generally controlled by changing the casting temperature and the casting speed. In addition, the melting / transition ratio of the β crystal can be controlled by the roll temperature in the longitudinal stretching step, and by selecting the optimum production conditions for these two parameters of β crystal formation and its melting / transition, A rough surface property can be obtained.

[Projection peak height (Rpk)]
The protruding peak height (Rpk) in the load curve obtained from the roughness curve of the film surface on the outermost layer side of the peelable film of the present invention is preferably 0.200 μm or less from the viewpoint of enhancing the smoothness of the peelable film. More preferably 0.150 μm or less, more preferably 0.130 μm or less, more preferably 0.100 μm or less, more preferably 0.090 μm or less, more preferably 0.080 μm or less, more preferably 0.04 μm or less, more Preferably it is 0.03 micrometer or less, More preferably, it is 0.02 micrometer or less. The protruding peak height (Rpk) is usually 0.005 μm or more, preferably 0.008 μm or more.

The protruding peak height (Rpk) is the average height of the protruding peak above the core of the roughness curve, calculated from the height characteristics according to the linear load curve, according to JISB-0671-2: 2002. Then, while removing the influence of continuous undulations on the film surface, it is possible to accurately determine the state of the protruding protrusion, that is, the abnormal protrusion, which has a large influence on the contact with the adherend. It is an indicator.

Projection peak height (Rpk) should be measured by contact method using a stylus, non-contact method using visible light reflection, laser beam interference, or atomic force phase difference measurement using a scanning probe microscope (SPM / AFM). Can do.

Such an Rpk value means the average height of the abnormal protrusions that protrude outside the core portion of the roughness curve, and the larger this value, the more abnormal protrusions on the film surface, that is, the biting on the adherend. Is a shape that tends to cause sticking that causes a large peeling force. When this value is small, the protruding peak portion having few abnormal protruding portions and hardly sticking to the adherend has a smooth plateau structure, which is preferable as the surface of the film for peeling.

[T-peel peel strength]
The T-peel peel strength of the film surface on the outermost layer side of the peelable film of the present invention with respect to the polyester adhesive tape is 23 ° C. T-peel when (a) 1 hour or (b) 20 hours at a humidity of 50%, and when the measurement sample is heated at 110 ° C for 2 minutes and then left at 23 ° C and 50% humidity for 20 hours Measured as peel force.

[T-peel peeling force when the measurement sample is heated at 23 ° C. for 2 minutes and then left at 23 ° C. and 50% humidity for (a) 1 hour or (b) 20 hours]
The T-peel peel strength of the peelable film is measured by the following method.
A polyester adhesive tape (Nitto Denko Co., Ltd. NO.31B tape, acrylic adhesive) with a width of 50 mm and a length of 200 mm is pasted on the outermost surface of the peelable film by reciprocating a 2 kg roller twice. To do. The obtained film is heat-treated at 23 ° C. for 2 minutes, and then allowed to stand (a) for 1 hour in an environment of a temperature of 23 ° C. and a humidity of 50%. A sample cut into a width of 25 mm from the obtained film was used as a measurement sample, and T-peel peeling was performed at a rate of 1000 mm / min using a tensile tester (for example, Universal Tensile Tester Technograph TGI-1kN manufactured by Minebea Co., Ltd.). And the peel force at that time is measured. The value measured in this way is defined as T-peel peeling force (after heat treatment at 23 ° C. for 2 minutes, left at 23 ° C. and 50% humidity for 1 hour).
Further, the T-peel peeling force is measured in the same manner as in the above method except that (a) 1 hour is replaced with (b) 20 hours. The value measured in this manner is defined as T-peel peeling force (after heat treatment at 23 ° C. for 2 minutes, left at 23 ° C. and 50% humidity for 20 hours).

The T-peel peeling force on the polyester adhesive tape on the film surface on the outermost layer side of the peelable film of the present invention does not depend on the standing time at 23 ° C. That is, the same T-peel peeling force can be obtained whether the standing time at 23 ° C. is (a) 1 hour or (b) 20 hours.
T-peel peel strength (after heat treatment at 23 ° C. for 2 minutes, then left at 23 ° C. and 50% humidity for 1 hour) or T-peel peel force (after heat treatment at 23 ° C. for 2 minutes, at 23 ° C. and 50% humidity) From the viewpoint of easily improving the adhesion of the peelable film to the adherend, it is preferably 0.1 N / 25 mm or more, more preferably 0.15 N / 25 mm or more, and further preferably 0.2 N / 25 mm. That's it. The T-peel peeling force is preferably 1.0 N / 25 mm or less, more preferably 0.9 N / 25 mm or less, and more preferably 0.8 N / 25 mm or less from the viewpoint of easily improving peelability. More preferably, it is 0.7 N / 25 mm or less, and still more preferably 0.5 N / 25 mm or less.

[T-peel peel strength when the measurement sample is heated at 110 ° C. for 2 minutes and then left at 23 ° C. and 50% humidity for 20 hours]
The T-peel peeling force (23 ° C. after 2 minutes of heat treatment at 23 ° C., except that the temperature for the heat treatment for 2 minutes was changed to 110 ° C. instead of 23 ° C. and the standing time was changed to 20 hours instead of 1 hour. The T-peel peeling force is measured in the same manner as in the measuring method of (Still for 1 hour at 50% humidity). The value measured in this manner is defined as T-peel peel strength (after heat treatment at 110 ° C. for 2 minutes, left at 23 ° C. and 50% humidity for 20 hours).
The T-peel peel strength (after heat treatment at 110 ° C. for 2 minutes, then left at 23 ° C. and 50% humidity for 1 hour) is preferably 0.1 N from the viewpoint of easily improving the adhesion of the peelable film to the adherend. / 25 mm or more, more preferably 0.15 N / 25 mm or more, still more preferably 0.2 N / 25 mm or more. The T-peel peeling force is preferably 4.0 N / 25 mm or less, more preferably 3.6 N / 25 mm or less, and even more preferably 3.2 N / 25 mm or less from the viewpoint of easily improving peelability. More preferably, it is 2.5 N / 25 mm or less, More preferably, it is 2.0 N / 25 mm or less, More preferably, it is 1.7 N / 25 mm or less, More preferably, it is 1.0 N / 25 mm or less, More Preferably it is 0.9 N / 25 mm or less, More preferably, it is 0.8 N / 25 mm or less, More preferably, it is 0.7 N / 25 mm or less.

When the resin component constituting the intermediate layer contains a structural unit derived from styrene, it is easy to improve the heat resistance of the peelable film. Therefore, when the peelable film is treated at a high temperature, the T-peel peel strength of the peelable film is difficult to decrease. That is, when a structural unit derived from styrene is contained in the resin component constituting the intermediate layer, the T-peel peel strength of the peelable film (after heat treatment at 110 ° C. for 2 minutes, at 23 ° C. and 50% humidity) 20 hours standing) is preferably T-peel peel strength (heat treatment at 23 ° C. for 2 minutes and then left at 23 ° C. and 50% humidity for 1 hour) or T-peel peel force (heat at 23 ° C. for 2 minutes) After the treatment, it is only slightly decreased from 23 ° C. and left at 50% humidity for 20 hours, and more preferably, the T-peel peeling force (after heat treatment at 23 ° C. for 2 minutes, 1 at 23 ° C. and 50% humidity). Time standing) or T-peel peeling force (after heat treatment at 23 ° C. for 2 minutes, standing at 23 ° C. and 50% humidity for 20 hours).

[Thickness of peelable film]
The thickness of the peelable film of the present invention is preferably 18 μm or more, more preferably 20 μm or more, from the viewpoint of handleability as a peelable film. The thickness of the peelable film is preferably 100 μm or less and more preferably 50 μm or less from the viewpoint of handleability as a peelable film. The thickness of the peelable film of the present invention is measured according to JIS C-2151 using a micrometer (JIS B-7502).

[Haze of peelable film]
The haze of the peelable film of the present invention is not particularly limited. When the base material layer is transparent, the haze of the peelable film of the present invention is preferably 15% or less, more preferably 12.5% or less, more preferably 11.5% or less, more preferably 10. It is 5% or less, more preferably 8% or less, further preferably 5% or less, and particularly preferably 4% or less. The haze value (cloudiness) is measured using a known haze meter or the like. A high haze value (cloudiness) (in the case of a thin film generally having a low internal haze) indicates a rough surface.

[Stretching of peelable film]
The peelable film of the present invention may or may not be stretched. Since the outermost layer is preferably unstretched from the viewpoint of easily obtaining good light releasability, it is preferable that the releasable film of the present invention is not stretched.

<The 2nd peelable film of this invention>
The second peelable film of the present invention (hereinafter sometimes simply referred to as “the peelable film of the present invention”) is a peelable film in which at least a base material layer and an outermost layer are laminated in order. The outermost layer contains a resin component as a main component, the specific gravity of the resin component is 1.15 g · cm ⁻³ or less, and the glass transition temperature of the resin component is −10 to 75 ° C. It is.
The second peelable film of the present invention is a film in which at least a base material layer and an outermost layer are sequentially laminated. For example, an intermediate layer described later may be formed between the base material layer and the outermost layer.

In recent years, when considering films for use as release films, release liners or separator films for use in surface protection films and adhesive tapes in the manufacturing process of electronic components or electronic substrates, and carriers used in the manufacture of composite materials The use of peeling the film at a high speed (for example, 1000 mm / min or more, 3000 mm / min or more, 5000 mm / min or more, 10000 mm / min or more, etc.) is regarded as important. This usage is because of a request to increase the processing speed (that is, a request to improve productivity). In such a use application called high-speed peeling, light peelability is important. However, in the above-mentioned film of Patent Document 1, since the peeling force when peeling at the above-described high speed is too high, the film is wrinkled or broken. The present inventors have found that there are problems such as. Therefore, there is still a need for a film that has good peelability when peeled at a low speed and also has good peelability when peeled at a high speed.
As a result of repeated studies by the present inventors, the above problem is also solved when the specific gravity of the resin component, which is the main component of the outermost layer of the film, and the glass transition temperature are combined within a specific range, respectively. As a result, the present invention has been completed. That is, the second peelable film of the present invention has a good peelability that the peel force is light, has excellent film surface smoothness, and excellent film surface strength, and further peels at a low speed. In addition to having good peelability, the film also has good peelability when peeled at a high speed.
[Base material layer]
The base material layer in the 2nd peelable film of this invention can use the thing similar to the base material layer in the 1st peelable film of this invention. Therefore, description of the base material layer is omitted here.
[Middle layer]
The 2nd peelable film of this invention may have the intermediate | middle layer formed in the at least one surface of the said base material layer. More preferably, in the second peelable film of the present invention, an intermediate layer may be formed between the base material layer and the outermost layer. An intermediate | middle layer can raise the adhesiveness of a base material layer and the outermost layer mentioned later, for example, and can raise the intensity | strength of a film. The intermediate layer in the second peelable film of the present invention can be the same as the intermediate layer in the first peelable film of the present invention. For example, (1) the resin component contained in the intermediate layer and its physical properties, (2) the method for producing the intermediate layer, (3) various physical properties such as the thickness of the intermediate layer, etc. are the first peelability of the present invention described above. This is the same as the description of the intermediate layer in the film. Therefore, the description of the intermediate layer is omitted here.
[Outermost layer]
The 2nd peelable film of this invention has the outermost layer formed on the said base material layer. The outermost layer is a layer for imparting peelability to the second peelable film of the present invention, and is a layer containing a resin component as a main component. Here, the main component means a component having the largest content in the outermost layer. The content of the resin component in the outermost layer is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 90% by mass or more, and 95% by mass with respect to all components contained in the outermost layer. % Or more is more preferable, 98 mass% or more is especially preferable, and 99 mass% or more is the most preferable. The upper limit of the content of the resin component in the outermost layer is 100% by mass. As will be described later, the outermost layer may contain components other than the resin component (for example, additives).

The specific gravity of the resin component that is the main component of the outermost layer is 1.15 g · cm ⁻³ or less. When the specific gravity of the resin component, which is the main component of the outermost layer of the second peelable film of the present invention, exceeds 1.15 g · cm ⁻³ , the peel strength of the film is too strong. There is a possibility of adversely affecting tangible objects (for example, electronic parts) on the side to be attached. Wherein the upper limit value of the specific gravity of the resin component which is the outermost layer of the main component is preferably 1.0 g · ^{cm -3} or less, more preferably 0.95 g · ^{cm -3} or less, 0.9 g · ^{cm -3} or less More preferred is 0.85 g · cm ⁻³ or less.
The lower limit of the specific gravity of the resin component that is the main component of the outermost layer is preferably at least 0.5 g · cm ⁻³ or more, more preferably 0.6 g · cm ⁻³ or more, and 0.7 g · cm ⁻³ or more. Is more preferable, and 0.8 g · cm ⁻³ or more is particularly preferable. When the specific gravity of the resin component, which is the main component of the outermost layer of the second peelable film of the present invention, is less than 0.5 g · cm ⁻³ , it is the main component of the outermost layer before peeling off from the tangible object to be pasted. The resin may cause cohesive failure.
In addition, when the said resin component is 2 types, or 3 or more types of resin components, the said specific gravity points out the specific gravity of the said 2 types, or 3 or more types of resin component whole.

The glass transition temperature of the resin component as the main component of the outermost layer is -10 to 75 ° C. When the glass transition temperature of the resin component that is the main component of the outermost layer of the second peelable film of the present invention is lower than −10 ° C., it is held for a long time while being stuck to the tangible object to be stuck, or held at a high temperature. If this is done, there is a risk that the peel force will not decrease when peeling from a tangible object at high speed. Moreover, when the glass transition temperature of the resin component exceeds 75 ° C., the peeling force of the film is too strong, and thus the tangible object (for example, an electronic component) on the side to be attached that causes wrinkles or breaks in the film There is a risk of adverse effects.
In addition, when the said resin component is 2 types, or 3 or more types of resin components, the said glass transition temperature points out the glass transition temperature of the said 2 types, or 3 or more types of resin component whole.
The resin component in the outermost layer is not particularly limited, but is a structural unit derived from 4-methylpentene-1 (4-methyl-1-pentene) (hereinafter referred to as “configuration derived from 4-methylpentene-1”). It may be preferable to include a unit. In this specification, a structural unit may be called a structural part, a structural unit, or a structural part. The content of the structural unit is not limited. In the second peelable film of the present invention, even if the resin component of the outermost layer does not contain a structural unit derived from 4-methylpentene-1, the specific gravity and glass transition temperature of the resin component are respectively defined in the present invention. The effect of the present invention is achieved when the specific gravity and glass transition temperature are satisfied.
When the resin component of the outermost layer which is a suitable example of the 2nd peelable film of this invention contains the structural unit derived from 4-methylpentene-1, the outermost layer in the 2nd peelable film of this invention is The same thing as the outermost layer in the 1st peelable film of this invention can be used. For example, (1) the resin component contained in the outermost layer and its physical properties, (2) the method for producing the outermost layer, (3) the physical properties such as the thickness of the outermost layer, etc. are the first peelability of the present invention described above. This is the same as the description of the outermost layer in the film. Therefore, explanation of the outermost layer (explanation other than the specific gravity and glass transition temperature of the resin component as the main component of the outermost layer) is omitted here.

[Other items]
About each item, such as the additive in the 2nd peelable film of this invention, the roughening of a film surface, protrusion peak part height, film thickness, haze, extending | stretching, the said in the 1st peelable film of this invention It is the same as each item. Therefore, description of each item is omitted here.

[Peeling force of the second peelable film of the present invention]
From the viewpoint of easily increasing the adhesiveness of the peelable film to the adherend, the T-peel peel force (300 mm / min) on the polyester adhesive tape on the film surface on the outermost layer side of the second peelable film of the present invention is as follows. Preferably it is 0.1 N / 25 mm or more, More preferably, it is 0.15 N / 25 mm or more, More preferably, it is 0.2 N / 25 mm or more, Most preferably, it is 1 N / 25 mm or more. The T-peel peeling force (300 mm / min) on the polyester adhesive tape on the film surface on the outermost layer side of the second peelable film of the present invention is preferably 2.0 N / 25 mm or less from the viewpoint of easily improving peelability. More preferably, it is 1.5 N / 25 mm or less, More preferably, it is 1.3 N / 25 mm or less, Most preferably, it is 1.2 N / 25 mm or less. The T-peel peeling force of the peelable film is a polyester adhesive tape having a width of 50 mm and a length of 200 mm on the surface of the outermost layer of the peelable film (Nitto Denko Corporation NO.31B tape, acrylic adhesive). Is applied by reciprocating a 2 kg roller twice to obtain a pre-processed adhesive product, and then the adhesive product is heat-treated at 23 ° C. for 2 minutes, and a weight is applied so that a load of 5 KPa is obtained. A sample cut out to a width of 25 mm from a film obtained by allowing it to stand for 20 hours in an environment of 23 ° C. and 50% humidity is used as a measurement sample, and a tensile tester (for example, Kyowa Interface Science Co., Ltd., adhesive -It measures as peeling force at the time of performing T-peel peeling at a speed of 300 mm / min using a film peeling analyzer VP-2). In the present invention and the present specification, the peeling force is also referred to as “P _A ” for convenience.

From the viewpoint of easily improving the adhesion of the peelable film to the adherend, the T-peel peel force (1000 mm / min) on the polyester adhesive tape on the film surface on the outermost layer side of the second peelable film of the present invention. Preferably it is 0.05 N / 25 mm or more, More preferably, it is 0.08 N / 25 mm or more, More preferably, it is 0.1 N / 25 mm or more, Most preferably, it is 0.4 N / 25 mm or more. The T-peel peeling force (1000 mm / min) on the polyester adhesive tape on the film surface on the outermost layer side of the second peelable film of the present invention is preferably 2.0 N / 25 mm or less from the viewpoint of easily improving peelability. More preferably, it is 1.5 N / 25 mm or less, More preferably, it is 1.3 N / 25 mm or less, Most preferably, it is 1 N / 25 mm or less. The above-described T-peel peel force (300 mm / min) is measured except that the T-peel peel force (1000 mm / min) of the peelable film is 1000 mm / min instead of 300 mm / min. It is the same as the method. In the present invention and the present specification, the peeling force is also referred to as “P _B ” for convenience.

From the viewpoint of easily increasing the adhesion of the peelable film to the adherend, the T-peel peel force (10000 mm / min) on the polyester adhesive tape on the film surface on the outermost layer side of the second peelable film of the present invention. Preferably it is 0.01 N / 25 mm or more, More preferably, it is 0.03 N / 25 mm or more, More preferably, it is 0.05 N / 25 mm or more, Most preferably, it is 0.1 N / 25 mm or more. The film surface on the outermost layer side of the second peelable film of the present invention has a T-peel peel strength (10000 mm / min) to the polyester adhesive tape, preferably 1.7 N / 25 mm or less from the viewpoint of easily improving the peelability. More preferably, it is 1.3 N / 25 mm or less, More preferably, it is 1.1 N / 25 mm or less, Most preferably, it is 1 N / 25 mm or less. The above-described T-peel peel force (300 mm / min) is measured except that the T-peel peel force (10000 mm / min) of the peelable film is 10000 mm / min instead of the speed of 300 mm / min. It is the same as the method. In the present invention, and also referred to herein as conveniently "P _C" the release force.

The T-peel peeling force (300 mm / min) to the polyester adhesive tape on the film surface on the outermost layer side of the peelable film after the heat treatment at 110 ° C. is applied to the second peelable film of the present invention. From the viewpoint of easily improving the adhesion of the peelable film to the adherend, preferably 0.1 N / 25 mm or more, more preferably 0.15 N / 25 mm or more, still more preferably 0.2 N / 25 mm or more, and particularly preferably 1 N. / 25 mm or more. The T-peel peeling force (300 mm / min) on the polyester adhesive tape on the film surface on the outermost layer side of the second peelable film of the present invention is preferably 2.0 N / 25 mm or less from the viewpoint of easily improving peelability. More preferably, it is 1.5 N / 25 mm or less, More preferably, it is 1.3 N / 25 mm or less, Most preferably, it is 1.2 N / 25 mm or less. The T-peel peel force (300 mm / min) of the peelable film was measured using the above-mentioned T-peel peel force (300 mm) except that the heat treatment for 2 minutes was performed at a temperature of 110 ° C. instead of a temperature of 23 ° C. / Min). In the present invention and the present specification, the peeling force is also referred to as “P _A ′” for convenience.

The T-peel peeling force (1000 mm / min) to the polyester adhesive tape on the film surface on the outermost layer side of the peelable film after heat treatment at 110 ° C. is applied to the second peelable film of the present invention. From the viewpoint of easily improving the adhesion of the peelable film to the adherend, it is preferably 0.05 N / 25 mm or more, more preferably 0.08 N / 25 mm or more, still more preferably 0.1 N / 25 mm or more, and particularly preferably 0. 4 N / 25 mm or more. The T-peel peeling force (1000 mm / min) on the polyester adhesive tape on the film surface on the outermost layer side of the second peelable film of the present invention is preferably 2.0 N / 25 mm or less from the viewpoint of easily improving peelability. More preferably, it is 1.5 N / 25 mm or less, More preferably, it is 1.3 N / 25 mm or less, Most preferably, it is 1 N / 25 mm or less. The T-peel peel force (1000 mm / min) of the peelable film was measured using the above-mentioned T-peel peel force (1000 mm) except that the heat treatment for 2 minutes was performed at a temperature of 110 ° C. instead of a temperature of 23 ° C. / Min). In the present invention and the present specification, the peeling force is also referred to as “P _B ′” for convenience.

The T-peel peeling force (10000 mm / min) with respect to the polyester adhesive tape of the film surface on the outermost layer side of the peelable film after the heat treatment at 110 ° C. is applied to the second peelable film of the present invention. From the viewpoint of easily improving the adhesion of the peelable film to the adherend, preferably 0.01 N / 25 mm or more, more preferably 0.03 N / 25 mm or more, still more preferably 0.05 N / 25 mm or more, particularly preferably 0. .1 N / 25 mm or more. The film surface on the outermost layer side of the second peelable film of the present invention has a T-peel peel strength (10000 mm / min) to the polyester adhesive tape, preferably 1.7 N / 25 mm or less from the viewpoint of easily improving the peelability. More preferably, it is 1.3 N / 25 mm or less, More preferably, it is 1.1 N / 25 mm or less, Most preferably, it is 1 N / 25 mm or less. The T-peel peel force (10000 mm / min) of the peelable film was measured using the above-mentioned T-peel peel force (10000 mm) except that the heat treatment for 2 minutes was performed at a temperature of 110 ° C. instead of a temperature of 23 ° C. / Min). In the present invention, and also referred to herein as conveniently "P _{C '"} the release force.

The second _P B / _{P A} values of the peelable film of the present invention is preferably from 0.1 to 0.7, more preferably 0.2 to 0.5, more preferably 0.3 to 0.45. When the P _B / P _A value is within the above range, both workability such as transporting a release film roll and workability in a high speed region (for example, 1000 mm / min or more, 3000 mm / min or more) are achieved. be able to.

The second _P C / _{P A} values of the peelable film of the present invention is preferably from 0.05 to 0.6, and more preferably 0.1 to 0.5, more preferably 0.2 to 0.4. When the P _C / P _A value is within the above range, both workability such as transporting a release film roll and workability in an ultra-high speed region (eg, 5000 mm / min or more, 10000 mm / min or more, etc.) are compatible. can do.

The second _{P A} '/ _{P A} values of the peelable film of the present invention, preferably 0.9 to 1.1. When the P _A ′ / P _A value is within the above range, it is difficult to be affected by the surrounding temperature change, and the workability such as transporting the release film roll is good, which is preferable.

The P _B '/ P _B value of the second peelable film of the present invention is preferably 0.9 to 1.1. By having the P _B '/ P _B value within the above range, it is difficult to be affected by temperature changes in the storage environment or the processing environment, and is stable in a high speed region (eg, 1000 mm / min or more, 3000 mm / min or more). It is possible to obtain properties.

The second release film of the present invention, _{P C} '/ _{P C} value, preferably 0.9 to 1.1. By _{P C} '/ P _C value is within the above range, less susceptible to temperature changes in storage environment or processing environment, ultra-high-speed region (e.g., 5000 mm / min or more, such as 10000 mm / min or more) stable in Workability can be obtained, which is preferable.
The second peelable film of the present invention has good peelability when peeled at low speed and also has good peelability when peeled at high speed. Are better. For example, the peelable film of the present invention is effective for high-speed peeling applications such as 1000 mm / min or more, 3000 mm / min or more, 5000 mm / min or more, and 10,000 mm / min or more.
The second peelable film of the present invention has a stable peel force regardless of the heat treatment temperature. Therefore, the peelable film of the present invention is also suitably used when used in an environment at a high temperature (in other words, for use in an environment at 100 ° C. or higher, for example).

[Use of the peelable film of the present invention]
Since the peelable film of the present invention (the first and second peelable films of the present invention) has good peelability and has both the smoothness of the film surface and the strength of the film, Are better. The peelable film of the present invention can be widely used in the medical field and the industrial field. For example, a peelable film, a release liner or Separator films, process separators used in the manufacture of semiconductor products (dicing, die bonding, back grinding) tape separators, unfired sheet forming carriers when manufacturing ceramic capacitors, composite materials manufacturing carriers, protective material separator films, etc. Preferably used. The peelable film of the present invention includes a tape or a sheet; a resin member such as an electric device, an electronic device, a wearable device, a medical device, and a building material; an intermediate member manufactured in the process of manufacturing the semiconductor product; Motor, connector, switch, etc.); used as the carrier; the object; dry film resist; In addition, when the above-mentioned adherend has an adhesive layer (for example, a solvent-based, emulsion-based, or hot-melt pressure-sensitive adhesive layer), the outermost layer of the peelable film of the present invention and the adhesive layer The peelable film of the present invention may be attached to an adherend so that is adhered. The method for attaching the peelable film of the present invention to an object is not particularly limited. The peelable film of the present invention may be applied to an object by, for example, appropriately cutting and attaching the peelable film according to the area to be pasted. When wound into a shape, they may be bonded together by roll-to-roll.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. Unless otherwise specified, parts and% represent “parts by mass” and “% by mass”, respectively. “/” Indicates “÷”. For example, a speed of 1000 mm / min (1000 mm / min) indicates 1000 mm per minute, and a P _B / P _A value means P _B ÷ P _A.

[Measurement method and evaluation method]
Various measurement methods and evaluation methods in Examples and Comparative Examples are as follows.

[Melt flow rate at 230 ° C.]
According to JISK-7210 (1999), a resin having a melting point of 220 ° C. or higher was measured under conditions of a temperature of 260 ° C. and a load of 49.03 N, and other resins were measured under a temperature of 230 ° C. and a load of 21.18 N.

[Melting point]
The melting point of the resin component was calculated by the following procedure using an input compensated DSCD diamond DSC manufactured by Perkin Elmer.
First, 2 mg of the resin component was weighed and packed in an aluminum sample holder. The sample holder is set in a DSC apparatus, heated from 0 ° C. to 280 ° C. at a rate of 10 ° C./min under nitrogen flow, held at 280 ° C. for 5 minutes, cooled to −50 ° C. at 10 ° C./min, After 5 minutes at 50 ° C., the endothermic peak when the temperature was increased again to 280 ° C. at 10 ° C./min was defined as the melting point of the resin component. When a plurality of peaks are detected, the peak detected on the highest temperature side is adopted as the melting point. If no clear endothermic peak is observed, the melting point is not observed.

[Acid Value of Polyolefin Resin B1 Having Carboxyl Group]
It measured by the method based on JIS0070 (neutralization titration method).

[Hydroxyl value of polyolefin resin B2 having a hydroxyl group]
It measured by the method based on JIS0070 (neutralization titration method).

[Thickness of intermediate layer and outermost layer]
Measuring instrument: Ryoka System Co., Ltd. optical interference surface / layer cross-sectional shape measuring instrument VertScan (registered trademark) 2.0
In the layer thickness measurement mode (bearing measurement) of the measuring machine, the refractive index of the base material layer (PET base material layer = 1.60, OPP base material layer = 1.51, nylon 6 base material layer = 1.58), The optical distance of each layer was calculated | required from the refractive index 1.48 of the intermediate | middle layer and the outermost layer, and the thickness of the intermediate | middle layer and the outermost layer was measured.

[Thickness of base material layer and film]
The thickness of the peelable film and the base material layer was measured based on JIS C-2151 using a micrometer (JIS B-7502).

[Degree of haze]
The sample cut into 50 mm x 100 mm was measured using Nippon Denshoku Co., Ltd. haze meter NDH-5000. The number of measurements was 3, and the average value was adopted.

[Projection peak height (Rpk)]
Measuring instrument: Ryoka System Co., Ltd. optical interference surface / layer cross-sectional shape measuring instrument VertScan (registered trademark) 2.0
Of the core level difference (Rk), protruding peak height Rpk, and protruding valley depth (Rvk) defined in JIS B-0671-2: 2002, the core level difference (Rk) and protruding peak Height (Rpk) was used as an index.

[Surface strength (1)]
Nitto Denko Corporation NO. An index of the surface strength of the peelable film by evaluating the transferability of the outermost layer to the peeled polyester tape at the time of measuring the T-peel peel strength using 31B tape (polyester tape with an acrylic pressure-sensitive adhesive). (31B evaluation).
A: No transition of the outermost layer to the peeled polyester tape is observed.
B: Although a part of the outermost layer was transferred to the peeled polyester tape, there is no problem as a product.
C: The outermost layer completely transferred to the peeled polyester tape.
[Surface strength (2)]
Nitto Denko Corporation NO. The transferability of the outermost layer to the peeled polyester tape at the time of measuring the T-peel peel strength using a 31D tape (polyester tape with rubber-based adhesive) was determined as NO. Evaluation was made according to the same criteria as for 31B tape and used as an index of the surface strength of the peelable film (31D evaluation).

[T-peel peel strength (after heat treatment at 23 ° C. for 2 minutes, then left at 23 ° C. and humidity 50% for 1 hour) and T-peel peel force (after heat treatment at 23 ° C. for 2 minutes, 23 ° C. and humidity 50%) Left for 20 hours))]
A polyester adhesive tape (Nitto Denko NO.31B tape, acrylic adhesive) with a width of 50 mm and a length of 200 mm is applied to the outermost surface of the peelable film by reciprocating a 2 kg roller twice. A pre-treatment patch was obtained.
Next, the patch was heat-treated at 23 ° C. for 2 minutes. In the heat treatment, a hot air dryer was used. Here, the heat treatment at 23 ° C. for 2 minutes means that the patch is placed in a hot air dryer set at 23 ° C.
Next, a weight was placed on the patch so as to obtain a load of 5 KPa, and left at (a) 1 hour or (b) 20 hours in an environment of 23% at a humidity of 50%.
Samples obtained by cutting the obtained post-treatment patch products to a width of 25 mm were used as measurement samples, and a peeling tester (manufactured by Kyowa Interface Science Co., Ltd., adhesive / film peeling analyzer VP-2) was used to obtain 1000 mm / min. A T-peel peel test was performed at a speed, and the peel force at that time was measured. Each measurement is carried out three times, and the average value of each peelable film's T-peel peel strength (heat treatment at 23 ° C. for 2 minutes, then left at 23 ° C. and 50% humidity for 1 hour) and T-peel peel peel Force (heat treatment at 23 ° C. for 2 minutes and then left at 23 ° C. and 50% humidity for 20 hours). For Example 14 and Comparative Examples 7 to 12, not only the speed of 1000 mm / min but also 300 mm / min and 10000 mm / min were used using the post-processed patch obtained by leaving for (b) 20 hours. A T peel peel test was conducted at a rate of minutes.

[T-peel peel strength (after heat treatment at 110 ° C. for 2 minutes, left at 23 ° C. and humidity 50% for 20 hours)]
For the heat treatment for 2 minutes, the T-peel peeling force (2 minutes at 23 ° C. for 2 minutes) except that the temperature of the heat treatment was changed to 110 ° C. instead of 23 ° C. and the standing time was changed to 20 hours instead of 1 hour. After the heat treatment, a post-treatment patch was obtained in the same manner as in the case of standing at 23 ° C. and 50% humidity for 1 hour. Samples obtained by cutting the patch after treatment to a width of 25 mm were used as measurement samples, and T was peeled off at a rate of 1000 mm / min using a peel tester (manufactured by Kyowa Interface Science Co., Ltd., adhesive / film peel analyzer VP-2). A peel test was performed, and the peel force at that time was measured. Each measurement was performed three times, and the average value was defined as the T-peel peel strength of each peelable film (after heat treatment at 110 ° C. for 2 minutes, left at 23 ° C. and 50% humidity for 20 hours). For Example 14 and Comparative Examples 7 to 12, not only the speed of 1000 mm / min but also the speeds of 300 mm / min and 10000 mm / min were used after treatment, which was obtained by allowing to stand for 20 hours. A T-peel peel test was performed.

〔specific gravity〕
First, each resin component (EP1013, Tuffmer XM7070, Syxen NC, COC8007, Elitel UE3200, Cybinol EK108, S-Rec BL-S) was used and dispersed in toluene to a concentration of 4% by mass. Next, using a reflux apparatus, the dispersion was stirred at 110 ° C. for 1 hour to dissolve each resin component, and the solution was cooled. Thereby, the coating liquid A (for forming the outermost layer) was obtained.
Next, the coating liquid A was dropped on a polytetrafluoroethylene plate and dried for 20 hours to produce a resin film.
Next, the resin film was peeled from the polytetrafluoroethylene plate.
Next, the specific gravity of each of the resin films was measured using a gas displacement density measuring device (Accumic II 1340 manufactured by Micromeritics).

〔Glass-transition temperature〕
Each resin film was obtained in the same manner as in the above [specific gravity] measurement.
Next, the glass transition temperature of the resin film was measured using a differential scanning calorimeter (Diamond DSC, manufactured by Perkin Elmer Co.) in accordance with JIS 7121. Specifically, 5 mg of the resin film was packed in an aluminum pan, heated to 200 ° C., held at 200 ° C. for 5 minutes, cooled to −40 ° C. at 10 ° C./minute, and held at −40 ° C. for 5 minutes. After that, it was obtained from an endothermic curve when the temperature was raised at 10 ° C./min.

Resins used in the following examples are as follows.
A1: EP1013 (4-methylpentene-1 polymer)
A2: TPX (registered trademark) EP0518 (4-methylpentene-1 polymer)
A3: TPX (registered trademark) DX845 (4-methylpentene-1 polymer)
A4: TPX (registered trademark) MX002 (4-methylpentene-1 polymer)
A′5: TAFMER (registered trademark) BL3450 (C ₂ -C ₄ random polyolefin)
A′6: TAFMER (registered trademark) XM7070 (C ₃ -C ₄ random polyolefin)
B1: Unistor (registered trademark) P-401 (polyolefin resin having a carboxyl group)
B2: Unistor (registered trademark) P-901 (polyolefin resin having a hydroxyl group)
B3: Bayronal (registered trademark) MD-110 (polyester resin)
B4: Bayronal (registered trademark) MD-133 (polyester resin)
B5: Aron Melt PPET1303S (polyolefin resin containing a styrene-derived structural unit and having a carboxyl group)
B6: Aron Melt PPET 1505SG (polyolefin resin containing a styrene-derived structural unit and having a carboxyl group)

Example 1
An acid-modified polyolefin resin (“Unistor (registered trademark) P-401” manufactured by Mitsui Chemicals, Inc., acid value 55 mgKOH / g, solid content 8%) is used as the polyolefin resin B1 having a carboxyl group, and the concentration is 2% by mass. As a result, the resin was diluted with toluene to obtain a coating solution B for forming an intermediate layer.
As a resin component constituting the outermost layer, a 4-methylpentene-1 polymer A1 “EP1013” (Mitsui Chemicals, MFR = 10 g / 10 min (temperature) containing a structural unit derived from 4-methylpentene-1 The polymer A1 was dispersed in toluene at 230 ° C., a load of 21.18 N), and a melting point of 130 ° C. to a concentration of 5% by mass. Next, using a reflux apparatus, the dispersion is stirred at 110 ° C. for 1 hour to dissolve the 4-methylpentene-1 polymer A1 and cooled to obtain a coating liquid A for forming the outermost layer. It was.
A biaxially stretched polyethylene terephthalate film (“E5100” manufactured by Toyobo Co., Ltd.) having a thickness of 38 μm was used as the base material layer. The coating liquid B was applied onto the base material layer using a Mayer bar and dried at 100 ° C. for 1 minute in an explosion-proof dryer to obtain a laminate having a base material layer and an intermediate layer.
Next, the coating liquid A is applied onto the intermediate layer of the obtained laminate using a Meyer bar and dried at 100 ° C. for 1 minute in an explosion-proof dryer, and the base layer, the intermediate layer, and the outermost layer are dried. A peelable film having a surface layer was obtained.

Example 2
The outermost layer is formed by the same method as in Example 1 except that the concentration of the 4-methylpentene-1 polymer A1 in the coating liquid A is 10% by mass instead of 5% by mass. A coating liquid A was obtained.
Subsequently, the laminated body which has a base material layer and an intermediate | middle layer by the method similar to Example 1 was obtained.
Next, the outermost layer was formed by the same method as in Example 1 except that the thickness of the outermost layer finally obtained was changed to 1.2 μm instead of 0.6 μm, and the base layer, the intermediate layer, and the outermost layer were formed. A peelable film was obtained.

Example 3
As a resin component constituting the outermost layer, a 4-methylpentene-1 polymer A2 containing a structural unit derived from 4-methylpentene-1 instead of the 4-methylpentene-1 polymer A1 “EP1013” Except for using “TPX (registered trademark) EP0518” (manufactured by Mitsui Chemicals, MFR = 4 g / 10 min (temperature 230 ° C., load 21.18 N), melting point 180 ° C.), the same method as in Example 1, A peelable film was obtained.

Example 4
As the resin component constituting the outermost layer, instead of 100 parts by mass of 4-methylpentene-1 polymer A1 “EP1013”, 50 parts by mass of 4-methylpentene-1 polymer A1 “EP1013” and 4- A peelable film was obtained in the same manner as in Example 1 except that 50 parts by mass of methylpentene-1 polymer A2 “TPX (registered trademark) EP0518” was used.

Example 5
As a resin component constituting the outermost layer, instead of 4-methylpentene-1 polymer A1 “EP1013”, 4-methylpentene-1 polymer A3 containing a structural unit derived from 4-methylpentene-1 Except for using “TPX (registered trademark) DX845” (Mitsui Chemicals, MFR = 9 g / 10 min (temperature 260 ° C., load 49.03 N), melting point 233 ° C.), the same method as in Example 1, A peelable film was obtained.

Example 6
As a resin component constituting the outermost layer, instead of 4-methylpentene-1 polymer A1 “EP1013”, 4-methylpentene-1 polymer A4 containing a structural unit derived from 4-methylpentene-1 TPX (registered trademark) MX002 ”(manufactured by Mitsui Chemicals, MFR = 21 g / 10 min (temperature 260 ° C., load 49.03 N), melting point 224 ° C.) was used. Further, as a resin component constituting the intermediate layer, a polyolefin resin B2 having a hydroxyl group (“Unistor (registered trademark) P-” manufactured by Mitsui Chemicals, Inc.) is used instead of the polyolefin resin B1 having a carboxyl group (acid-modified polyolefin resin). 901 ", hydroxyl value 50 mgKOH / g). Except for the contents described above, a peelable film was obtained by the same method as in Example 1.

Example 7
Instead of polyolefin resin B1 having a carboxyl group (acid-modified polyolefin resin) as a resin component constituting the intermediate layer, a polyolefin resin B2 having a hydroxyl group (“Unistor (registered trademark) P-901” manufactured by Mitsui Chemicals, Inc.) A peelable film was obtained in the same manner as in Example 1 except that a hydroxyl value of 50 mgKOH / g) was used.

Example 8
As the resin component constituting the outermost layer, instead of 100 parts by mass of 4-methylpentene-1 polymer A1 “EP1013”, 50 parts by mass of 4-methylpentene-1 polymer A1 “EP1013”, 4- Polyolefin resin A′5 “Tuffmer (registered trademark) BL3450” (Mitsui Chemicals, MFR = 9 g / 10 min (temperature 230 ° C., load 21.18 N), which does not contain a structural unit derived from methylpentene-1; A peelable film was obtained in the same manner as in Example 1 except that 50 parts by mass of a random polyolefin mainly composed of a structural unit derived from an olefin having a melting point of 100 ° C. and having 2 to 4 carbon atoms was used. .

Example 9
As the resin component constituting the outermost layer, instead of 100 parts by mass of 4-methylpentene-1 polymer A1 “EP1013”, 50 parts by mass of 4-methylpentene-1 polymer A1 “EP1013”, 4- Polyolefin resin A′6 “TAFMER (registered trademark) XM7070” (Mitsui Chemicals, MFR = 7 g / 10 min (temperature 230 ° C., load 21.18 N), which does not contain a structural unit derived from methylpentene-1; A peelable film was obtained in the same manner as in Example 1 except that 50 parts by mass of a random polyolefin mainly composed of a structural unit derived from an olefin having a melting point of 75 ° C. and 3 to 4 carbon atoms was used.

Example 10
As a base material layer, instead of a biaxially stretched polyethylene terephthalate film (“E5100” manufactured by Toyobo Co., Ltd.), a biaxially stretched polypropylene film having a thickness of 50 μm (“Alphan (registered trademark) E-201F manufactured by Oji F-Tex)” A peelable film was obtained in the same manner as in Example 1 except that # 50 ") was used.

Example 11
As a base material layer, instead of a biaxially stretched polyethylene terephthalate film (“E5100” manufactured by Toyobo Co., Ltd.), a biaxially stretched nylon 6 film having a thickness of 25 μm (“Emblem (registered trademark) ON” manufactured by Unitika Ltd.) A peelable film was obtained in the same manner as in Example 1 except that was used.

Example 12
Instead of polyolefin resin B1 having a carboxyl group (acid-modified polyolefin resin) as a resin component constituting the intermediate layer, a polyolefin resin B5 having a carboxyl group and containing a structural unit derived from styrene (Aronmelt PPET1303S manufactured by Toagosei Co., Ltd.) ) Was used to obtain a peelable film by the same method as in Example 1.

Example 13
Instead of polyolefin resin B1 having a carboxyl group (acid-modified polyolefin resin) as a resin component constituting the intermediate layer, a polyolefin resin B6 containing a structural unit derived from styrene and having a carboxyl group (Aronmelt PPET1505SG manufactured by Toagosei Co., Ltd.) ) Was used to obtain a peelable film by the same method as in Example 1.

Comparative Example 1
As a resin component constituting the outermost layer, a 4-methylpentene-1 polymer A1 “EP1013” (Mitsui Chemicals, MFR = 10 g / 10 min (temperature) containing a structural unit derived from 4-methylpentene-1 The polymer A1 was dispersed in toluene at 230 ° C., a load of 21.18 N), and a melting point of 130 ° C. to a concentration of 5% by mass. Next, using a reflux apparatus, the dispersion is stirred at 110 ° C. for 1 hour to dissolve the 4-methylpentene-1 polymer A1 and cooled to obtain a coating liquid A for forming the outermost layer. It was.
A biaxially stretched polyethylene terephthalate film (“E5100” manufactured by Toyobo Co., Ltd.) having a thickness of 38 μm was used as the base material layer. The coating liquid A was applied onto the base material layer using a Mayer bar, and dried at 100 ° C. for 1 minute in an explosion-proof dryer to obtain a laminate. The obtained laminate was used as a film having no intermediate layer.

Comparative Example 2
Instead of polyolefin resin B1 (acid-modified polyolefin resin) having a carboxyl group as a resin component constituting the intermediate layer, polyester resin B3 (“Vyronal (registered trademark) MD-110” manufactured by Toyobo Co., Ltd.), acid value of 3 mgKOH / g A peelable film was obtained in the same manner as in Example 1 except that a hydroxyl value of 5 mgKOH / g) was used.

Comparative Example 3
Instead of polyolefin resin B1 having a carboxyl group (acid-modified polyolefin resin) as a resin component constituting the intermediate layer, polyester resin B4 (“Vylonal (registered trademark) MD-133” manufactured by Toyobo Co., Ltd.), acid value of 3 mgKOH / g A peelable film was obtained in the same manner as in Example 1 except that a hydroxyl value of 15 mgKOH / g) was used.

Comparative Example 4
As a resin component constituting the outermost layer, instead of the 4-methylpentene-1 polymer A1 “EP1013”, a polyolefin resin A′5 “Toughmer (registered) which does not contain a structural unit derived from 4-methylpentene-1 (Trademark) BL3450 "(Mitsui Chemicals, MFR = 9 g / 10 min (temperature 230 ° C., load 21.18 N), melting point 100 ° C., structural unit derived from an olefin having 2 to 4 carbon atoms) A peelable film was obtained in the same manner as in Example 1 except that (random polyolefin) was used.

Comparative Example 5
As a resin component constituting the outermost layer, instead of the 4-methylpentene-1 polymer A1 “EP1013”, a polyolefin resin A′6 “Tuffmer (registered) which does not contain a structural unit derived from 4-methylpentene-1 (Trademark) XM7070 "(Mitsui Chemicals, MFR = 7 g / 10 min (temperature 230 ° C., load 21.18 N), melting point 75 ° C., structural unit derived from olefin having 3 to 4 carbon atoms) A peelable film was obtained in the same manner as in Example 1 except that (random polyolefin) was used.

Comparative Example 6
A biaxially stretched polyethylene terephthalate film (“E5100” manufactured by Toyobo Co., Ltd.) having a thickness of 38 μm was prepared. That is, in Comparative Example 6, only the base material layer is present, and neither the intermediate layer nor the outermost layer is present.

The thickness of each layer of the films obtained in Examples 1 to 13 and Comparative Examples 1 to 6, the haze degree, the height of the protruding ridge, the surface strength, the T-peel peeling force, after heat treatment at 23 ° C. for 2 minutes, T-peel peeling force at a peeling rate of 1000 mm / min after standing at 50% humidity for 1 hour, heat treatment at 110 ° C. for 2 minutes, and then peeling rate at 1000 mm after standing at 23 ° C. and 50% humidity for 20 hours Table 1 shows the results of measuring the T-peel peel force at 1 min.

As shown in Table 1, it can be seen that the peelable film of the present invention has a good peelability that the peel strength is light, and has both the smoothness of the film surface and the strength of the film. Therefore, since the smoothness of the film surface is high, the surface shape of the peelable film of the present invention is not transferred to the adherend surface to which the film is stuck, and the strength of the film is sufficiently high. When the peelable film is peeled from the adherend surface, a part of the peelable film does not move to the adherend surface.
These excellent properties of the peelable film of the present invention were obtained without depending on the type of substrate layer and the standing time at 23 ° C. (a) 1 hour or (b) 20 hours.
When 4-methylpentene-1-based resin A1 having a lower melting point was used (Examples 1, 2, 4, 7 to 13), NO. In the 31B tape (polyester tape with acrylic adhesive) surface strength evaluation, NO. It is excellent also in 31D tape (polyester tape with rubber adhesive) surface strength evaluation. Therefore, it is excellent as a peelable film.
On the other hand, when 4-methylpentene-1-series resin A2, A3 or A4 having a higher melting point is used (Examples 3, 5 and 6), and carboxyl group-containing polyolefin resin B5 containing a structural unit derived from styrene or When B6 was used (Examples 12 and 13), even after heat treatment at a high temperature of 110 ° C., the T-peel peeling force on the polyester adhesive tape was as low as that after heat treatment at 23 ° C. It was. From these results, it is understood that when the resin B1 or B2 contained in the intermediate layer is a resin having a higher melting point or a resin containing a structural unit derived from styrene, the light release property is maintained even after high temperature storage. Therefore, it is excellent as a peelable film.
On the other hand, the film of Comparative Example 1 composed only of the outermost layer and the base material layer and Comparative Examples 2 and 3 having no specific intermediate layer did not have sufficient surface strength. In addition, Comparative Examples 4 and 5 and a base material having no specific outermost layer (that is, the resin component constituting the outermost layer is a resin component not containing a structural unit derived from 4-methylpentene-1) The film of Comparative Example 6 consisting only of layers did not show sufficient peelability because the peel force was too high.

Example 14
A special polyolefin resin ("Surflen (registered trademark) P-1000" manufactured by Mitsubishi Chemical Corporation, maleated hydrogenated styrene-butadiene-styrene block copolymer) was used and diluted with toluene to a concentration of 2% by mass. . Thereby, the coating liquid B for forming an intermediate | middle layer was obtained.
Next, as a resin component constituting the outermost layer, a 4-methylpentene-1 polymer A1 “EP1013” (Mitsui Chemicals, MFR = 10 g / 10) containing a structural unit derived from 4-methylpentene-1. Minutes (temperature 230 ° C., load 21.18 N), melting point 130 ° C., specific gravity 0.834 g · cm ⁻³ , glass transition temperature 40 ° C.) and dispersed in toluene to a concentration of 4% by mass. Subsequently, using a reflux apparatus, the dispersion was stirred at 110 ° C. for 1 hour to dissolve the 4-methylpentene-1 polymer, and the solution was further cooled. Thereby, the coating liquid A for forming the outermost layer was obtained.
Next, a biaxially stretched polyethylene terephthalate film (“Diafoil T100” manufactured by Mitsubishi Plastics, Inc.) having a thickness of 38 μm was used as the base material layer. Next, the coating liquid B was applied onto the base material layer using a Mayer bar, and dried at 110 ° C. for 1 minute in an explosion-proof dryer, and the base material layer and the intermediate layer (thickness: 0.2 μm) ) Was obtained.
Next, on the intermediate layer of the obtained laminate, the coating liquid A was applied using a Meyer bar, and dried at 110 ° C. for 1 minute in an explosion-proof dryer, and the outermost layer (thickness: 0.5 μm) ) Was formed. This obtained the peelable film which has a base material layer, an intermediate | middle layer, and an outermost layer.

Comparative Example 7
As a resin component constituting the outermost layer, instead of 4-methylpentene-1 polymer-containing resin A1 “EP1013”, α-olefin copolymer “Tuffmer XM7070” (manufactured by Mitsui Chemicals, Inc., specific gravity 0.88 g · A peelable film was obtained by the same method as in Example 14 except that cm ⁻³ , glass transition temperature −15 ° C.) was used.

Comparative Example 8
As a resin component constituting the outermost layer, instead of 4-methylpentene-1 polymer-containing resin A1 “EP1013”, polyolefin “Zyxen NC” (manufactured by Sumitomo Seika Co., Ltd., specific gravity 0.94 g · cm ⁻³ , A peelable film was obtained in the same manner as in Example 14 except that the glass transition temperature was −50 ° C.

Comparative Example 9
As a resin component constituting the outermost layer, instead of 4-methylpentene-1 polymer-containing resin A1 “EP1013”, a cyclic olefin copolymer “COC8007” manufactured by Topas Advanced Polymers, specific gravity 1.01 g · cm ^{− 3} and a glass transition temperature of 78 ° C.), a peelable film was obtained in the same manner as in Example 14.

Comparative Example 10
As a resin component constituting the outermost layer, instead of 4-methylpentene-1 polymer-containing resin A1 “EP1013”, a cyclic olefin copolymer “Eritel UE3200” manufactured by Unitika Ltd., specific gravity 1.25 g · cm ^{− 3} and a glass transition temperature of 65 ° C.) was used to obtain a peelable film by the same method as in Example 14.

Comparative Example 11
As a resin component constituting the outermost layer, instead of the 4-methylpentene-1 polymer-containing resin A1 “EP1013”, an acrylic resin “Cybinol EK108” manufactured by Seiden Chemical Co., Ltd., specific gravity 1.19 g · cm ⁻³ , glass transition A peelable film was obtained in the same manner as in Example 14 except that the temperature was 56 ° C.

Comparative Example 12
As a resin component constituting the outermost layer, instead of 4-methylpentene-1 polymer-containing resin A1 “EP1013”, a polyacetal resin “ESREC BL-S” manufactured by Sekisui Chemical Co., Ltd., specific gravity 1.42 g · cm ⁻³ A peelable film was obtained in the same manner as in Example 14 except that glass transition temperature 61 ° C.) was used.

(A) Specific gravity of outermost layer of each peelable film obtained in Example 14 and Comparative Examples 7 to 12, (b) Glass transition temperature (Tg) of outermost layer, (c) T-peel peeling force (23 ° C. treatment) ), (D) Table 2 shows the results of T-peel peeling force (110 ° C. treatment). Also,
(E) T-peel peeling force at a peeling speed of 300 mm / min after treatment at 23 ° C. (T-peel peeling force at a peeling speed of 300 mm / min in (c) above) is expressed as P _A ,
(F) The T-peel peel force when the peel rate after treatment at 23 ° C. is 1000 mm / min (T-peel peel force when the peel rate is 1000 mm / min in (c) above) is P _B ,
(G) The T-peel peel force when the peel rate after treatment at 23 ° C. is 10,000 mm / min (T-peel peel force when the peel rate is 10,000 mm / min in the above (c)) is expressed as P _C ,
(H) 110 ° C. treated release rate of 300 mm / min T-peeling force when the post (the (T-peel peeling strength at a peeling speed of 300 mm / min in d)) the _{P A} ',
(I) T-peel peeling force at a peeling rate of 1000 mm / min after treatment at 110 ° C. (T-peel peeling force at a peeling rate of 1000 mm / min in (d) above) is expressed as P _B ′,
(J) The T-peel peel force when the peel rate after treatment at 110 ° C. is 10,000 mm / min (T-peel peel force when the peel rate is 10,000 mm / min in the above (d)) is expressed as P _C ′,
And the _time, P B / _{P A values,} P C / _{P A} value, _{P A} '/ _{P A} values, _{P B'} / _{P B} value, together the results of the _{P C} '/ _{P C} values in Table 2 Show.
In addition, the thickness of the outermost layer of Example 14 is 0.5 μm, the thickness of the intermediate layer is 0.2 μm, the haze degree of Example 14 is 4.3, the protruding ridge height Rpk is 0.025 μm, and the surface strength. (1) (31B evaluation) was A (A evaluation), and surface strength (2) (31D evaluation) was A (A evaluation).

As shown in Table 2, in the peelable (for peeling) film of Example 14, the specific gravity of the resin component that is the main component of the outermost layer is 1.15 g · cm ⁻³ or less, and the resin component The glass transition temperature is −10 to 75 ° C. for that reason,
(1) Each peeling force when the heat treatment temperature is 23 ° C. and 110 ° C. shows a finite value (exceeds 0) and shows a low value. Therefore, the peelable film of the present invention including the film of Example 14 can be effectively used for peeling. Also,
(2) Accelerated peeling change rates P _B / P _A and P _C / P _A are the above desired values. Therefore, the peelable film of the present invention including the film of Example 14 is useful as a peelable (peelable) film, and is particularly useful as a peelable (peelable) film for high-speed peeling. Also,
_{(3) P A '/ P} A values, _{P B'} showing the peel force heat treatment temperature dependence / _{P B} value, _{P C} '/ _{P C} value is above the desired value, respectively. Therefore, the film of Example 14 has a stable peel force regardless of the heat treatment temperature. Therefore, the peelable film of the present invention including the film of Example 14 is particularly useful as a peelable (peelable) film that is stable with respect to temperature without depending on the temperature environment.

1: base material layer 2: intermediate layer 3: outermost layer (surface layer)

Claims (12)

1. A peelable film formed by laminating a base material layer, an intermediate layer formed on at least one surface of the base material layer, and an outermost layer formed on the intermediate layer,
   The intermediate layer contains at least one selected from the group consisting of a polyolefin resin B1 having a carboxyl group and a polyolefin resin B2 having a hydroxyl group,
   The outermost layer contains a resin component as a main component, and the resin component includes a structural unit derived from 4-methylpentene-1.
   Release film.
2. The peelable film according to claim 1, wherein the resin component comprises (1) 4-methylpentene-1 polymer A.
3. The exfoliation according to claim 1 or 2 in which said resin ingredient contains olefin system resin A 'other than (1) 4-methylpentene-1 system A and (2) 4-methylpentene-1 system polymer A. Sex film.
4. The T-peel peeling force (1000 mm / min) for the polyester adhesive tape after standing for 1 hour at 23 ° C. and 50% humidity on the film surface on the outermost layer side is 0.1 to 1.0 N / 25 mm. The peelable film according to any one of claims 1 to 3.
5. The peelable film according to any one of claims 1 to 4, wherein the polymer A has a melting point in the range of 80 ° C to 240 ° C.
6. The peelable film according to any one of claims 1 to 5, wherein the polymer A has a melting point in the range of 100 ° C or higher and lower than 160 ° C.
7. The peelable film according to any one of claims 1 to 6, wherein the outermost layer has a thickness of 0.1 to 3.0 µm.
8. The peelable film according to any one of claims 1 to 7, wherein the resin component constituting the intermediate layer contains a structural unit derived from styrene.
9. The peelable film according to any one of claims 1 to 8, wherein the polyolefin resin B1 is a polyolefin obtained by graft copolymerization of maleic acid and / or maleic anhydride.
10. The peelable film according to any one of claims 1 to 9, wherein the polyolefin resin B2 is a polyolefin obtained by graft copolymerization of a hydroxyl group-containing (meth) acrylic acid ester and / or a hydroxyl group-containing vinyl ether.
11. The peelable film according to any one of claims 1 to 10, wherein the intermediate layer has a thickness of 0.04 to 1.5 µm.
12. The peelable film according to any one of claims 1 to 11, wherein a protruding peak height (Rpk) in a load curve obtained from a roughness curve of the film surface on the outermost layer side is 0.005 to 0.200 µm. .

Images