Laminated Film

Abstract

To provide a laminated film which is excellent in unevenness followability and releasability even at a high temperature of 200°C or higher, is low in interlayer adhesive strength and linear expansion coefficient, and is suitable for a release film.SOLUTION: The present invention relates to the laminated film including a substrate layer (X) and a surface layer (Y). The substrate layer (X) is an olefin polymer composition (M) containing 5 to 100 pts.mass of a 4-methyl-1-pentene copolymer (A-1) satisfying specific requirements and 95 to 0 pt.mass of at least one olefinic polymer (B) selected from an ethylene-based polymer (D), a propylene-based polymer (C), and a butene-based polymer (E) [provided that the total of the component (A-1) and the component (B) is 100 pts.mass]. The surface layer (Y) contains at least one thermoplastic resin selected from the group consisting of a 4-methyl-1-pentene (co)polymer, polybutylene terephthalate, and polyfluoroethylene.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a laminated film having a base layer and a surface layer. More specifically, the present invention relates to a laminated film suitable for use as a release film in the production processes of electronic products, building materials, automobile parts, and fiber-reinforced composite materials. More specifically, the present invention relates to a laminated film suitable for use as a release film for molding fiber-reinforced composite materials, which is placed between the inner surface of a mold when molding a prepreg of the fiber-reinforced composite material in the mold, a release film for semiconductor or LED element encapsulation processes, which is placed between a semiconductor chip or LED element and the inner surface of a mold when placing the semiconductor chip or LED element in the mold and injecting resin into the mold, and a release film for producing printed wiring boards for fixing and wiring electronic components. [Background technology]

[0002] When molding fiber-reinforced resin, a prepreg is generally used, in which reinforcing fibers such as carbon fiber or glass fiber are impregnated with resin. This prepreg is then heated and molded into the desired shape.

[0003] Printed wiring boards for fixing and wiring electronic components include rigid boards, flexible printed boards, rigid-flexible boards, etc. In particular, when manufacturing flexible printed boards (hereinafter also referred to as "FPCs"), a process of laminating a coverlay film on a board on which a circuit pattern has been formed, and a heat press molding process of sandwiching the obtained laminate between heat press plates and applying heat and pressure are usually provided.

[0004] Furthermore, semiconductor chips are typically used as semiconductor resin packages encapsulated with an encapsulant. Semiconductor resin packages are generally obtained by transfer molding, in which the semiconductor chip is loaded into a mold cavity and the cavity is filled with an encapsulant primarily composed of epoxy resin. Conventional transfer molding has had problems such as the encapsulant sometimes contaminating the inner surface of the mold, reducing work efficiency, damaging the inner surface of the mold and shortening the mold's lifespan, and easily producing burrs on the molded semiconductor resin package.

[0005] In this case, to solve the above problems, release films made of fluorine-based polymer films such as polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, and polyvinyl fluoride, polymethylpentene film, polybutylene terephthalate, and syndiotactic polystyrene are used (Patent Document 1).

[0006] In particular, it has been proposed to use a film made of poly-4-methyl-1-pentene resin as a release film, because it has excellent heat resistance, releasability after heating and pressurization, and conformability to the circuit board.Since poly-4-methyl-1-pentene has a high melting point of 235°C, a release film has been disclosed that has excellent heat resistance, releasability, and contamination resistance even in the molding of copper-clad laminates, which is carried out at a temperature of about 180°C (Patent Document 2).

[0007] Also known are a protective film made of a 4-methyl-1-pentene polymer and an olefin elastomer (Patent Document 3), and a film formed from a composition of a 4-methylpentene polymer and an olefin elastomer (Patent Document 4).

[0008] On the other hand, in order to improve the elastic modulus of 4-methyl-1-pentene polymer film at high temperatures, a laminated release film has been proposed in which a crystalline polymethylpentene layer is formed on both the inner and outer surfaces and the intermediate layer is made of polyamide or polyester (Patent Document 5), and a laminated release film has been proposed in which the intermediate layer is made of a flexible layer to provide conformability to molded bodies with uneven surfaces (Patent Document 6).However, it was necessary to further balance heat resistance and flexibility. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-350601 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-98257 [Patent Document 3] International Publication No. 2015 / 012274 [Patent Document 4] International Publication No. 2013 / 099876 [Patent Document 5] Japanese Patent Publication No. 2020-142474 [Patent Document 6] Japanese Patent Application Laid-Open No. 2014-121830 Summary of the Invention [Problem to be solved by the invention]

[0010] Release films are now required to have higher levels of conformability to uneven surfaces and releasability, but the above-mentioned conventional release films have not been able to meet these requirements. The present invention has been made in view of the above circumstances and aims to solve the above problems. That is, the present invention aims to obtain a laminated film suitable for use as a release film, which has excellent conformability and releasability even at high temperatures of 200°C or higher, and which has a low interlayer adhesion strength and a low linear expansion coefficient. [Means for solving the problem]

[0011] In view of the above problems, the inventors conducted extensive research and discovered that the above problems could be solved by a laminated film having a substrate layer made of a specific resin composition, thereby completing the present invention.

[0012] An example of a specific means for solving the above problem is as follows. [1] It includes a substrate layer (X) and a surface layer (Y), the base layer (X) is an olefin polymer composition (M) containing 5 to 100 parts by mass of a 4-methyl-1-pentene copolymer (A-1) satisfying the following requirements (a) to (e), and 95 to 0 parts by mass of at least one olefin polymer (B) selected from an ethylene polymer (D), a propylene polymer (C), and a butene polymer (E) (wherein the total of the components (A-1) and (B) is 100 parts by mass); A laminated film characterized in that the surface layer (Y) contains at least one thermoplastic resin selected from the group consisting of 4-methyl-1-pentene (co)polymer, polybutylene terephthalate, and polyethylene fluoride: [4-methyl-1-pentene copolymer (A-1)] (a) 97 to 60 mol % of structural units derived from 4-methyl-1-pentene and 3 to 40 mol % of structural units derived from at least one selected from ethylene or an α-olefin having 3 to 4 carbon atoms (wherein the total amount of structural units derived from 4-methyl-1-pentene and structural units derived from ethylene or an α-olefin having 3 to 4 carbon atoms is 100 mol %), (b) Intrinsic viscosity [η] measured in decalin at 135°C in the range of 0.5 to 5.0 dl / g; (c) The melting point (Tm) measured by DSC is 199°C or less, or is substantially unobservable. (d) a molecular weight distribution (Mw / Mn), which is the ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) measured by gel permeation chromatography (GPC), in the range of 1.0 to 3.5; and (e) Density is 825 to 860 kg / m 3 is in the range.

[0013] [2] 2. The laminated film according to claim 1, wherein the thermoplastic resin is a 4-methyl-1-pentene (co)polymer (A-2) that satisfies the following requirements (g) to (i): [4-methyl-1-pentene (co)polymer (A-2)] (g) The content of structural units derived from 4-methyl-1-pentene is 100 to 90 mol %, and the content of structural units derived from at least one selected from α-olefins having 10 to 20 carbon atoms (excluding 4-methyl-1-pentene) is 0 to 10 mol % (wherein the total amount of structural units derived from 4-methyl-1-pentene and structural units derived from α-olefins having 10 to 20 carbon atoms is 100 mol %), (h) a melting point (Tm) measured by DSC in the range of 200 to 250°C; and (i) Density is 820 to 850 kg / m 3 is in the range.

[0014] [3] Item [1] or [2], wherein the olefin resin (B) constituting the olefin polymer composition (M) is a propylene polymer (C).

[0015] [4] Item 3. The laminated film according to item 3, wherein the propylene polymer (C) contains 70 to 100 mol % of structural units derived from propylene and 30 to 0 mol % of structural units derived from at least one selected from ethylene or an α-olefin having 4 to 20 carbon atoms (wherein the total amount of structural units derived from propylene and structural units derived from ethylene or an α-olefin having 4 to 20 carbon atoms is taken as 100 mol %).

[0016] [5] The laminated film according to any one of items [1] to [4], which has a three or more layer structure consisting of a surface layer (Y), a base layer (X), and a surface layer (Y) in this order.

[0017] [6] The laminate film according to any one of items [1] to [5], wherein the laminate film is a laminate film obtained by a T-die film forming method.

[0018] [7] A release film for producing a fiber-reinforced composite material, comprising the laminate film according to any one of items [1] to [6].

[0019] [8] A release film for producing a flexible printed circuit board, comprising the laminate film according to any one of items [1] to [6].

[0020] [9] A release film for semiconductor production, comprising the laminated film according to any one of items [1] to [6]. [Effects of the Invention]

[0021] In the laminate film of the present invention, the substrate layer (X) contains a specific 4-methyl-1-pentene copolymer (A-1). Therefore, the relaxivity of the substrate layer reduces the linear expansion coefficient of the entire laminate film, making the film less susceptible to wrinkles and poor appearance. In addition, the substrate layer (X) can exhibit unevenness-following ability while maintaining the releasability of the surface layer (Y).

[0022] Furthermore, a laminated film in which the surface layer (Y) contains one or more of a specific 4-methyl-1-pentene (co)polymer (A-2), polybutylene terephthalate, and polyethylene fluoride can have good releasability and can suppress interlayer delamination between the surface layer (Y) and the substrate layer (X).

[0023] Furthermore, the laminated film of the present invention is characterized by its excellent recyclability and low environmental impact, since it prevents impurities from migrating to the surface of the molded article and does not contain any halogen-based resin. DETAILED DESCRIPTION OF THE INVENTION

[0024] Specific embodiments of the present invention will be described in detail below, but the present invention is not limited to the following embodiments and can be implemented with appropriate modifications within the scope of the object of the present invention.

[0025] The release film according to the present invention is composed of at least two layers, namely, a base layer (X) and a surface layer (Y).

[0026] <Base material layer (X)> The substrate layer (X) constituting the laminated film of the present invention is composed of the following 4-methyl-1-pentene copolymer (A-1) alone or an olefin polymer composition (M) comprising the 4-methyl-1-pentene copolymer (A-1) and an olefin polymer (B) selected from an ethylene polymer (D), a propylene polymer (C), and a butene polymer (E).

[0027] The 4-methyl-1-pentene copolymer (A-1), the olefin polymer (B), and the olefin polymer composition (M) that form the substrate layer (X) will be described below.

[0028] [4-methyl-1-pentene copolymer (A-1)] The 4-methyl-1-pentene copolymer (A-1), which is another component forming the base layer (X) of the laminated film of the present invention (hereinafter, sometimes referred to as "copolymer (A-1)"), is a copolymer of 4-methyl-1-pentene and an α-olefin that satisfies the following requirements (a) to (e):

[0029] <Requirement (a)> The structural units derived from 4-methyl-1-pentene are 97 to 60 mol %, preferably 90 to 60 mol %, and more preferably 88 to 70 mol %, and the structural units derived from at least one selected from ethylene or an α-olefin having 3 to 4 carbon atoms are 3 to 40 mol %, preferably 10 to 40 mol %, and more preferably 12 to 30 mol % (wherein the total amount of structural units derived from 4-methyl-1-pentene and structural units derived from ethylene or an α-olefin having 3 to 4 carbon atoms is 100 mol %).

[0030] <Requirement (b)> The intrinsic viscosity [η] measured in decalin at 135° C. is in the range of 0.5 to 5.0 dl / g, preferably 0.7 to 4.0 dl / g, and more preferably 1.0 to 3.0 dl / g.

[0031] <Requirement (c)> The melting point (Tm) measured by DSC is 199°C or lower, preferably 180°C or lower, more preferably 160°C or lower, and particularly preferably 140°C or lower, or is not substantially observable.

[0032] <Requirement (d)> The molecular weight distribution (Mw / Mn), which is the ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) measured by gel permeation chromatography (GPC), is in the range of 1.0 to 3.5, preferably 1.5 to 3.0.

[0033] <Requirement (e)> Density: 825-860 kg / m 3 , preferably 830 to 850 kg / m 3 , and more preferably 833 to 845 kg / m 3 is in the range.

[0034] A laminated film containing the above-mentioned 4-methyl-1-pentene copolymer (A-1) in the base layer (X) can improve film formability, improve film tear strength, impart unevenness-following ability due to flexibility, and reduce the linear expansion coefficient. The 4-methyl-1-pentene·α-olefin copolymer (A-1) preferably satisfies the following requirement (f) in addition to the above requirements (a) to (e).

[0035] <Requirement (f)> The melt flow rate (MFR) of the 4-methyl-1-pentene-α-olefin copolymer (A-1) (measured according to ASTM D1238 at a temperature of 230°C and a load of 2.16 kgf) is preferably 4.0 to 30 g / 10 min, more preferably 5.0 to 15 g / 10 min, and even more preferably 7.0 to 13 g / 10 min.

[0036] [Olefin polymer (B)] The olefin polymer (B), which is one of the components constituting the olefin polymer composition (M) forming the base layer (X) constituting the laminated film of the present invention, is an olefin polymer selected from a propylene polymer (C), an ethylene polymer (D), and a butene polymer (E).

[0037] The olefin polymer (B) according to the present invention may be a propylene polymer (C), an ethylene polymer (D), or a butene polymer (E) either singly or as a composition (mixture) of two or more of them.

[0038] [Propylene polymer (C)] The propylene polymer (C), which is one of the olefin polymers (B) that are components of the olefin polymer composition (M) that forms the base layer (X) constituting the laminate film of the present invention, is a propylene homopolymer or a copolymer of propylene and ethylene or a copolymer having 4 to 20 carbon atoms, preferably ethylene or a copolymer having 4 to 8 carbon atoms. The monomer copolymerized with propylene may be a single monomer or two or more monomers.

[0039] The propylene polymer (C) according to the present invention usually contains 70 to 100 mol %, preferably 80 to 99 mol %, and more preferably 92 to 99 mol % of units derived from propylene (where the total amount of units derived from propylene and units derived from an α-olefin (including ethylene) is taken as 100 mol %).

[0040] The propylene polymer (C) according to the present invention usually has a density of 860 to 920 kg / m 3 , preferably 870 to 910 kg / m 3 , and more preferably 880 to 910 kg / m 3 The MFR measured in accordance with ASTM D1238 (measured at 230°C under a load of 2.16 kgf) is in the range of 0.1 to 100 g / 10 min, preferably 0.5 to 50 g / 10 min, and more preferably 1.0 to 20 g / 10 min.

[0041] The propylene polymer (C) according to the present invention usually has a melting point of 60 to 165° C., preferably 70 to 160° C., more preferably 70 to 140° C., and particularly preferably 90 to 130° C. For applications requiring greater flexibility, the melting point is preferably in the range of 60 to 130° C., more preferably 70 to 120° C. For applications requiring a higher tensile modulus, the melting point is preferably in the range of 130 to 175° C., more preferably 135 to 170° C.

[0042] When the propylene polymer (C) according to the present invention is used as one of the components of the olefin polymer composition (M) described below, one or more kinds of propylene polymers may be used. When two or more kinds of propylene polymers (C) are used, they may have different physical properties.

[0043] [Ethylene polymer (D)] The ethylene polymer (D), which is one of the olefin polymers (B) that constitute the olefin polymer composition (M) that forms the base layer (X) that constitutes the laminate film of the present invention, is an ethylene homopolymer or a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms.

[0044] The ethylene polymer (C) according to the present invention usually contains 70 to 100 mol %, preferably 80 to 99 mol %, and more preferably 92 to 99 mol % of units derived from ethylene (where the total amount of units derived from ethylene and units derived from α-olefins (including ethylene) is taken as 100 mol %).

[0045] The ethylene polymer (D) according to the present invention usually has a density of 850 to 960 kg / m 3 , preferably 850 to 930 kg / m 3 , and more preferably 850 to 900 kg / m 3 The MFR (measured at 190°C under a load of 2.16 kgf) according to ASTM D1238 is in the range of 0.1 to 100 g / 10 min, preferably 0.2 to 80 g / 10 min, and more preferably 0.5 to 20 g / 10 min.

[0046] When the ethylene polymer (D) according to the present invention is used as one of the components of the olefin polymer composition (M), one or more kinds of the ethylene polymers may be used. When two or more kinds of the ethylene polymers (D) are used, the ethylene polymers may have different physical properties.

[0047] [Butene polymer (E)] The butene polymer (E), which is one of the olefin polymers (B) that constitute the olefin polymer composition (M) that forms the base layer (X) constituting the laminate film of the present invention, is a homopolymer of 1-butene or a copolymer of 1-butene with one or more α-olefins selected from ethylene, propylene, and α-olefins having 5 to 20 carbon atoms.

[0048] The butene polymer (E) according to the present invention usually contains 70 to 100 mol %, preferably 80 to 99 mol %, and more preferably 92 to 99 mol % of units derived from 1-butene (where the total amount of units derived from 1-butene and units derived from an α-olefin (including ethylene) is taken as 100 mol %).

[0049] The butene polymer (E) according to the present invention usually has a density of 850 to 960 kg / m 3 , preferably 850 to 930 kg / m 3 , and more preferably 850 to 900 kg / m 3 The MFR (measured at 190°C under a load of 2.16 kgf) according to ASTM D1238 is in the range of 0.1 to 100 g / 10 min, preferably 0.2 to 80 g / 10 min, and more preferably 0.5 to 20 g / 10 min.

[0050] When the butene polymer (E) according to the present invention is used as one of the components of the olefin polymer composition (M) described below, one or more kinds of butene polymers may be used. When two or more kinds of butene polymers (E) are used, the butene polymers may have different physical properties.

[0051] [Olefin polymer composition (M)] The olefin polymer composition (M) constituting the base layer (X) of the laminated film of the present invention is a composition containing 5 to 100 parts by mass, preferably 20 to 100 parts by mass, of the 4-methyl-1-pentene copolymer (A-1) and 0 to 95 parts by mass, preferably 0 to 80 parts by mass, of the olefin polymer (B) (wherein the total of components (A) and (B) is taken as 100 parts by mass).

[0052] The olefin polymer composition (M) constituting the base layer (X) according to the present invention contains the above-mentioned 4-methyl-1-pentene copolymer (A-1) alone or contains a predetermined amount of the above-mentioned 4-methyl-1-pentene copolymer (A-1), thereby making it possible to provide the base layer (X) with excellent adhesion (interlayer peel strength) to the surface layer (Y) described below, and also to reduce the linear expansion coefficient.

[0053] The olefin polymer (B) such as the propylene polymer (C) and the ethylene polymer (D) contained in the olefin polymer composition (M) is a component necessary for the base layer (X) according to the present invention to maintain the elastic modulus, flexibility and conformability required for a film. In particular, the propylene polymer (C) is a polymer having a density of 870 to 905 kg / m 3 By using a propylene polymer in this range, a laminated film having an excellent balance between flexibility and conformability to irregularities can be obtained.

[0054] In addition to the above components (A-1) and (B), other resins or polymers and / or resin additives may be optionally added to the olefin polymer composition (M) according to the present invention, depending on the intended use, within the range that does not impair the effects of the present invention.

[0055] Examples of such resin additives include pigments, dyes, fillers, lubricants, plasticizers, release agents, antioxidants, flame retardants, UV absorbers, antibacterial agents, surfactants, antistatic agents, weather stabilizers, heat stabilizers, antislip agents, antiblocking agents, foaming agents, crystallization aids, antifogging agents, (transparent) nucleating agents, antioxidants, hydrochloric acid absorbers, impact modifiers, crosslinking agents, co-crosslinking agents, crosslinking aids, adhesives, softeners, processing aids, etc. These additives can be used alone or in appropriate combinations of two or more.

[0056] Examples of other resins or polymers to be added include polystyrene, acrylic resin, polyphenylene sulfide resin, polyether ether ketone resin, polyester resin, polysulfone, polyphenylene oxide, polyimide, polyetherimide, acrylonitrile-butadiene-styrene copolymer (ABS), ethylene-α-olefin copolymer rubber, conjugated diene rubber, phenol resin, melamine resin, polyester resin, silicone resin, epoxy resin, etc. The amount of these resins or polymers to be added is preferably 0.1 to 30% by mass based on the total mass of the olefin polymer composition (M).

[0057] Examples of pigments include inorganic pigments (titanium oxide, iron oxide, chromium oxide, cadmium sulfide, etc.) and organic pigments (azo lake pigments, thioindigo pigments, phthalocyanine pigments, anthraquinone pigments). Examples of dyes include azo pigments, anthraquinone pigments, triphenylmethane pigments, etc. The amount of these pigments and dyes added is not particularly limited, but is usually 5% by mass or less, preferably 0.1 to 3% by mass, in total, based on the total mass of the olefin polymer composition (M).

[0058] Examples of fillers include glass fiber, carbon fiber, silica fiber, metal (stainless steel, aluminum, titanium, copper, etc.) fiber, carbon black, silica, glass beads, silicates (calcium silicate, talc, clay, etc.), metal oxides (iron oxide, titanium oxide, alumina, etc.), metal carbonates (calcium sulfate, barium sulfate), various metal (magnesium, silicon, aluminum, titanium, copper, etc.) powders, mica, glass flakes, etc. These fillers may be used alone or in combination of two or more.

[0059] Examples of lubricants include waxes (such as carnauba wax), higher fatty acids (such as stearic acid), higher alcohols (such as stearyl alcohol), and higher fatty acid amides (such as stearic acid amide).

[0060] Examples of the plasticizer include aromatic carboxylic acid esters (dibutyl phthalate, etc.), aliphatic carboxylic acid esters (methyl acetylricinoleate, etc.), aliphatic dialkoxy esters (adipic acid-propylene glycol polyester, etc.), aliphatic tricarboxylic acid esters (triethyl citrate, etc.), phosphate triesters (triphenyl phosphate, etc.), epoxy fatty acid esters (epoxybutyl stearate, etc.), and petroleum resins.

[0061] Examples of the release agent include lower (C1-4) alcohol esters of higher fatty acids (butyl stearate, etc.), polyhydric alcohol esters of fatty acids (C4-30) (hardened castor oil, etc.), glycol esters of fatty acids, and liquid paraffin.

[0062] Examples of antioxidants include phenol-based (2,6-di-t-butyl-4-methylphenol, etc.), polycyclic phenol-based (2,2'-methylenebis(4-methyl-6-t-butylphenol, etc.)), phosphorus-based (tetrakis(2,4-di-t-butylphenyl)-4,4-biphenylenediphosphonate, etc.), and amine-based (N,N-diisopropyl-p-phenylenediamine, etc.) antioxidants.

[0063] Examples of the flame retardant include organic flame retardants (nitrogen-containing, sulfur-containing, silicon-containing, phosphorus-containing, etc.) and inorganic flame retardants (antimony trioxide, magnesium hydroxide, zinc borate, red phosphorus, etc.).

[0064] Examples of ultraviolet absorbers include benzotriazole-based, benzophenone-based, salicylic acid-based, and acrylate-based ones. Examples of antibacterial agents include quaternary ammonium salts, pyridine compounds, organic acids, organic acid esters, halogenated phenols, and organic iodines.

[0065] Examples of surfactants include nonionic, anionic, cationic, and amphoteric surfactants. Nonionic surfactants include polyethylene glycol-based nonionic surfactants such as higher alcohol ethylene oxide adducts, fatty acid ethylene oxide adducts, higher alkylamine ethylene oxide adducts, and polypropylene glycol ethylene oxide adducts; polyhydric alcohol-based nonionic surfactants such as polyethylene oxide, glycerin fatty acid esters, pentaerythritol fatty acid esters, sorbitol or sorbitan fatty acid esters, polyhydric alcohol alkyl ethers, and alkanolamine fatty amides. Examples of anionic surfactants include sulfate ester salts such as alkali metal salts of higher fatty acids; sulfonates such as alkylbenzene sulfonates, alkyl sulfonates, and paraffin sulfonates; and phosphate ester salts such as higher alcohol phosphate ester salts. Examples of cationic surfactants include quaternary ammonium salts such as alkyltrimethylammonium salts. Examples of amphoteric surfactants include amino acid-based amphoteric surfactants such as higher alkylaminopropionates; and betaine-based amphoteric surfactants such as higher alkyldimethyl betaines and higher alkyldimethyl hydroxyethyl betaines.

[0066] Examples of the antistatic agent include the above-mentioned surfactants, fatty acid esters, and polymeric antistatic agents. Examples of the fatty acid esters include esters of stearic acid and oleic acid, and examples of the polymeric antistatic agents include polyether ester amides.

[0067] The amounts of the various additives such as the filler, lubricant, plasticizer, mold release agent, antioxidant, flame retardant, UV absorber, antibacterial agent, surfactant, and antistatic agent added are not particularly limited depending on the intended use as long as the object of the present invention is not impaired, but are preferably 0.1 to 30 mass % each relative to the total mass of the olefin polymer composition (M).

[0068] When the olefin polymer composition (M) according to the present invention is used to produce a laminated film, the 4-methyl-1-pentene copolymer (A-1) and the olefin copolymer (B) may be mixed in predetermined amounts and used, or they may be mixed and then kneaded to prepare the film.

[0069] <Surface layer (Y)> The surface layer (Y) constituting the laminated film of the present invention is not particularly limited, and may be, for example, a 4-methyl-1-pentene (co)polymer (A-2), polybutylene terephthalate, polyethylene fluoride, etc. Among these, it is preferable to use a 4-methyl-1-pentene (co)polymer (A-2) that satisfies the following requirements (g) to (i):

[0070] [4-methyl-1-pentene (co)polymer (A-2)] The 4-methyl-1-pentene (co)polymer (A-2) (hereinafter sometimes referred to as "polymer (A-2)") constituting the surface layer (Y) of the laminate film of the present invention is a homopolymer of 4-methyl-1-pentene or a copolymer of 4-methyl-1-pentene and an α-olefin that satisfies the following requirements (g) to (i):

[0071] <Requirement (g)> The structural units derived from 4-methyl-1-pentene account for 100 to 90 mol %, preferably 99.9 to 92 mol %, and more preferably 99 to 95 mol %, and the structural units derived from at least one selected from α-olefins having 10 to 20 carbon atoms (excluding 4-methyl-1-pentene) account for 0 to 10 mol %, preferably 0.1 to 8 mol %, and more preferably 1 to 5 mol % (wherein the total amount of structural units derived from 4-methyl-1-pentene and structural units derived from ethylene and α-olefins having 10 to 20 carbon atoms is taken as 100 mol %).

[0072] <Requirement (h)> The melting point (Tm) measured by DSC is in the range of 200 to 250°C, preferably 210 to 245°C, and more preferably 220 to 240°C.

[0073] <Requirement (i)> Density: 820-850 kg / m 3 , preferably 825 to 845 kg / m 3 , and more preferably 830 to 840 kg / m 3 is in the range.

[0074] The 4-methyl-1-pentene (co)polymer (A-2) that satisfies the above requirements (g) to (i) has excellent heat resistance, and by using this polymer (A-2) in the surface layer (Y), a laminated film that is well-balanced with releasability can be obtained. The 4-methyl-1-pentene·α-olefin (co)polymer (A-2) preferably satisfies the following requirement (j) in addition to the above requirements (g) to (i).

[0075] <Requirement (j)> The melt flow rate (MFR) of the 4-methyl-1-pentene-α-olefin (co)polymer (A-2) (measured according to ASTM D1238 at a temperature of 230°C and a load of 5.0 kgf) is preferably 1 to 200 g / 10 min, more preferably 5 to 100 g / 10 min, and even more preferably 10 to 60 g / 10 min.

[0076] <Laminated film> The laminated film of the present invention is a laminated film having at least two layers, namely, the above-mentioned substrate layer (X) and the above-mentioned surface layer (Y).

[0077] The laminated film of the present invention has a base layer (X) made of the olefin polymer composition (M), and therefore has flexibility and good tear resistance. Therefore, it has sufficient conformability even when shaping an uneven molded body, and can suppress linear expansion changes at high temperatures, so it has excellent resistance to deformation and elongation during use, is capable of preventing film tearing, and does not wrinkle even at high temperatures.

[0078] Furthermore, a laminated film whose surface layer (Y) contains one or more of the above-mentioned 4-methyl-1-pentene (co)polymer (A-2), polybutylene terephthalate, and polyethylene fluoride can be used for molding at higher temperatures, and has a small critical surface tension, so that it has excellent releasability from molded articles and molds.

[0079] The thickness of the laminated film of the present invention can be appropriately determined as desired, but typically the thickness of the base layer (X) is in the range of 5 to 100 μm, preferably 10 to 80 μm, more preferably 10 to 50 μm, the thickness of the surface layer (Y) is in the range of 3 to 50 μm, preferably 5 to 40 μm, more preferably 5 to 20 μm, and the total thickness of the laminated film is in the range of 20 to 200 μm, preferably 30 to 170 μm, more preferably 50 to 150 μm.

[0080] The laminated film of the present invention may be a film in which the base layer (X) and the surface layer (Y) are in direct contact with each other, or may have an adhesive layer between the base layer (X) and the surface layer (Y) to improve the adhesive strength between the layers.

[0081] Furthermore, the laminate film of the present invention may be a two-layer film of base layer (X) / surface layer (Y), or may be a two-layer three-layer film of surface layer (Y) / base layer (X) / surface layer (Y), or may be a laminate film of three or more layers as long as it has a base layer (X) and a surface layer (Y).

[0082] When the laminated film of the present invention is a laminated film having three or more layers, the thicknesses of the surface layer (Y) and the base layer (X) each satisfy the above ranges, and the total thickness of the laminated film is in the range of 20 to 200 μm, preferably 30 to 170 μm, and more preferably 50 to 150 μm.

[0083] <Laminated film manufacturing method> The laminated film of the present invention can be produced by using various known film forming machines. Specifically, for example, a laminated film molding machine equipped with a lamination die (multilayer die) and at least two extruders is used, and an olefin polymer composition (M) to form the base layer (X) is fed into one extruder, and a 4-methyl-1-pentene polymer (A-2) to form the surface layer (Y) is fed into the other extruder to produce a laminated film having a structure of base layer (X) / surface layer (Y) or surface layer (Y) / base layer (X) / surface layer (Y). Alternatively, a laminated film may be produced by first forming the base layer (X) and then extrusion laminating the 4-methyl-1-pentene polymer (A-2) to form the surface layer (Y) onto the base layer (X). Alternatively, a film to form the base layer (X) and a film to form the surface layer (Y) may be separately produced, and then each film may be surface-treated or an adhesive or the like to form a laminated film consisting of base layer (X) / surface layer (Y).

[0084] <Applications of laminated film> The laminated film of the present invention can be used for various known applications, specifically, for example, release films for flexible printed circuit boards (FPCs), release films for ACM substrates, release films for rigid substrates, release films for rigid-flexible substrates, release films for advanced composite materials, release films for the production of fiber-reinforced composites, release films for curing carbon fiber composites, release films for molding carbon fiber composites, release films for curing glass fiber composites, release films for molding glass fiber composites, release films for curing aramid fiber composites, release films for molding aramid fiber composites, release films for curing nanocomposite materials, release films for curing filler materials, release films for sealing semiconductors, release films for polarizing plates, and release films for diffusion sheets. It can also be used as a release film for films such as films for films for prism sheets, release films for reflective sheets, cushion films for release films, release films for fuel cells, release films for various rubber sheets, release films for urethane curing, release films for epoxy curing, release films for silicone resins, release films for LED encapsulant molds, release films for acrylic adhesives, release films for protect films, and release films for synthetic leather, or as release papers such as release paper for synthetic leather, release paper for advanced composite materials, release paper for curing carbon fiber composites, release paper for curing glass fiber composites, release paper for curing aramid fiber composites, release paper for curing nanocomposite materials, and release paper for curing filler fillers, and heat-resistant, water-resistant photographic paper. [Example]

[0085] The present invention will be described below with reference to examples, but the present invention is not limited to these examples in any way.

[0086] [Measurement conditions, etc.] The measurement conditions for the following physical properties are as follows:

[0087] 〔composition〕 The contents of the structural units (i) and (ii) in the copolymer (A-1) and polymer (A-2) obtained in the following synthesis examples are: 13 Measurement was carried out by C-NMR using the following equipment and conditions.

[0088] The ECP500 nuclear magnetic resonance spectrometer manufactured by JEOL Ltd. was used. The solvent was a mixed solvent of o-dichlorobenzene / heavy benzene (80 / 20 vol%), the sample concentration was 55 mg / 0.6 mL, the measurement temperature was 120 °C, and the observation nuclei were 13 The measurement was performed using C (125 MHz), a sequence of single pulse proton decoupling, a pulse width of 4.7 μsec (45° pulse), a repetition time of 5.5 sec, and an accumulation number of 10,000 or more, with 27.50 ppm as the reference value of the chemical shift.

[0089] [Limiting viscosity] The intrinsic viscosity [η] (dl / g) of the copolymer (A-1) and polymer (A-2) obtained in the following synthesis examples was measured at 135° C. using decalin as a solvent.

[0090] Specifically, approximately 20 mg of polymer was dissolved in 15 ml of decalin, and the specific viscosity η sp After diluting this decalin solution by adding 5 ml of decalin solvent, the specific viscosity η sp This dilution procedure was repeated two more times, and the η when the concentration (C) was extrapolated to 0 was calculated as shown in the following formula (1). sp The / C value was taken as the intrinsic viscosity [η] (unit: dl / g). [η]=lim(η sp / C) (C→0) (1)

[0091] [Molecular weight and molecular weight distribution] The molecular weights of the copolymer (A-1) and polymer (A-2) obtained in the following synthesis examples were measured using a liquid chromatograph: Waters ALC / GPC 150-C plus model (integrated with a differential refractometer detector), two Tosoh GMH6-HT columns and two GMH6-HTL columns connected in series, o-dichlorobenzene as the mobile phase medium, at a flow rate of 1.0 ml / min and 140° C. The measurement time per sample was 60 minutes.

[0092] The obtained chromatogram was analyzed by a known method using a calibration curve prepared using a standard polystyrene sample to measure the weight-average molecular weight (Mw) and number-average molecular weight (Mn), and calculate the molecular weight distribution (Mw / Mn).

[0093] 〔density〕 The densities of the copolymer (A-1) and polymer (A-2) obtained in the following synthesis examples were calculated from the masses of each copolymer measured in water and air using an electronic densimeter MD-300S manufactured by Alpha Mirage Co., Ltd. in accordance with ASTM D 1505 (water displacement method).

[0094] [Melting point (Tm)] The melting point (Tm) of the polymer was measured by differential scanning calorimetry (DSC) using a DSC220C device manufactured by Seiko Instruments Inc.

[0095] Specifically, 7 to 12 mg of copolymer (A-1) or polymer (A-2) obtained in the following synthesis example was sealed in an aluminum pan and heated from room temperature to 200°C at 10°C / min. The pan was then held at 200°C for 5 minutes to completely melt the copolymer, and then cooled to -50°C at 10°C / min. After being left at -50°C for 5 minutes, the sample was heated again to 200°C at 10°C / min. The peak temperature during this second heating was taken as the melting point (Tm).

[0096] [MFR] According to ASTM D1238, the copolymer (A-1) was measured at a temperature of 230°C and a load of 2.16 kgf, and the polymer (A-2) was measured at a temperature of 260°C and a load of 5 kgf.

[0097] The physical properties of the laminated film were measured by the following methods. [Tensile test] The laminated film was cut into strips of 15 mm wide x 100 mm long to prepare test pieces. The tensile modulus (YM) (unit: MPa), tensile strength at break (TS) (unit: MPa), and elongation at break (EL) (unit: %) were measured in the MD and TD directions of the test pieces using a tensile tester (Universal Tensile Tester 3380, manufactured by Instron) in accordance with JIS K7127 (1999) under conditions of a chuck distance of 50 mm, a tensile speed of 200 mm / min, and a temperature of 23°C.

[0098] [Elmendrev tear strength] The Elmendorf tear strength of the laminated film was measured in both the MD and TD directions under conditions of 23°C and 55% RH, using a light-load tearing device manufactured by Toyo Seiki Co., Ltd., in accordance with JIS K7128-1991.

[0099] [Linear expansion coefficient] The laminated film was cut into strips measuring 5 mm wide and 10 mm long, and the rate of change was calculated for test pieces using a TMA7100C (Hitachi High-Tech Corporation) when a load of 5 gf (49 mN) was applied and the temperature was raised from room temperature (23°C) to 180°C at a rate of 5°C / min in extension mode.

[0100] Delamination The laminated film was cut into strips measuring 15 mm wide x 100 mm long (MD direction was the length direction) and the test pieces were measured in accordance with JIS K7127 (1999) using a tensile tester (Universal Tensile Tester 3380, Instron). A trigger point was created between the base layer (X) and the surface layer (Y), and the edges of each film were clamped with a chuck. The test pieces were peeled at an angle of 180°, at a tensile speed of 300 mm / min and a temperature of 23°C. In cases where the adhesive strength was too strong to create a trigger point, or where the films did not peel apart at the surface during the peel force measurement, resulting in a hole or breaking midway (cohesive peeling), the peel strength was deemed sufficiently strong and was recorded as "not peeled."

[0101] [Release property (contact angle measurement)] The critical interfacial tension was measured using a DropMaster500 image processing solid-liquid interface analysis system, using a wetting tension reagent mixture (manufactured by Wako Pure Chemical Industries, Ltd.) as the test liquid, in an environment of 23°C and 50% humidity, to measure the contact angle of the film obtained in the examples, and the critical interfacial tension was calculated based on the measured value. The smaller the critical interfacial tension, the higher the releasability for highly polar materials.

[0102] [Synthesis of 4-methyl-1-pentene copolymer (A-1)] [Synthesis example A-1-1] A 1.5-liter stainless steel autoclave equipped with a stirring blade and thoroughly purged with nitrogen was charged with 750 ml of 4-methyl-1-pentene at 23° C. 0.75 ml of a 1.0 mmol / ml toluene solution of triisobutylaluminum (TIBAL) was then charged into the autoclave, and the stirrer was turned on.

[0103] Next, the autoclave was heated to an internal temperature of 60°C and pressurized with propylene to a total pressure of 0.13 MPa (gauge pressure). Subsequently, 0.34 ml of a toluene solution containing 1 mmol of pre-prepared methylaluminoxane (calculated as Al) and 0.01 mmol of diphenylmethylene(1-ethyl-3-t-butyl-cyclopentadienyl)(2,7-di-t-butyl-fluorenyl)zirconium dichloride was pressure-charged into the autoclave with nitrogen to initiate polymerization. During the polymerization reaction, the autoclave's internal temperature was adjusted to 60°C. Sixty minutes after the start of polymerization, 5 ml of methanol was pressure-charged into the autoclave with nitrogen to terminate the polymerization, and the autoclave was depressurized to atmospheric pressure. Then, acetone was poured into the reaction solution while stirring.

[0104] The resulting powdery polymer containing the solvent was dried at 100°C under reduced pressure for 12 hours. The amount of the resulting 4-methyl-1-pentene-α-olefin copolymer (A-1-1) was 36.9 g, and the content of structural unit (i) in the polymer was 72.5 mol % and the content of structural unit (ii) was 27.5 mol %. The physical properties of the resulting copolymer (A-1-1) are shown in Table 1.

[0105] [Synthesis example A-1-2] A 1.5-liter stainless steel autoclave equipped with a stirrer and thoroughly purged with nitrogen was charged with 300 ml of normal hexane (dried over activated alumina in a dry nitrogen atmosphere) and 450 ml of 4-methyl-1-pentene at 23° C. 0.75 ml of a 1.0 mmol / ml toluene solution of triisobutylaluminum (TIBAL) was then charged into the autoclave, and the stirrer was turned on.

[0106] Next, the autoclave was heated to an internal temperature of 60°C and pressurized with propylene to a total pressure of 0.19 MPa (gauge pressure). Subsequently, 0.34 ml of a toluene solution containing 1 mmol of pre-prepared methylaluminoxane (calculated as Al) and 0.01 mmol of diphenylmethylene(1-ethyl-3-t-butyl-cyclopentadienyl)(2,7-di-t-butyl-fluorenyl)zirconium dichloride was pressure-charged into the autoclave with nitrogen to initiate polymerization. During the polymerization reaction, the autoclave's internal temperature was adjusted to 60°C. Sixty minutes after the start of polymerization, 5 ml of methanol was pressure-charged into the autoclave with nitrogen to terminate the polymerization, and the autoclave was depressurized to atmospheric pressure. Then, acetone was poured into the reaction solution while stirring.

[0107] The resulting powdery polymer containing the solvent was dried at 100°C under reduced pressure for 12 hours. The amount of the resulting copolymer (A-1-2) was 44.0 g, and the content of structural unit (i) in the polymer was 84.1 mol%, and the content of structural unit (ii) in the polymer was 15.9 mol%. The physical properties of the resulting copolymer are shown in Table 1.

[0108] [Production of 4-methyl-1-pentene (co)polymers (A-2-1) and (A-2-2)] Copolymers (A-2-1) and (A-2-2) having the physical properties shown in Table 1 were obtained by changing the proportions of 4-methyl-1-pentene, 1-decene, 1-hexadecene, 1-octadecene, and hydrogen in accordance with the polymerization methods described in Comparative Examples 7 and 9 of WO 2006 / 054613.

[0109] [Table 1]

[0110] [Example 1] A composition containing 100 parts by weight of copolymer (A-1-1) as the base layer (X) and 0.2 parts by weight of n-octadecyl-3-(4'-hydroxy-3',5'-di-t-butylphenyl) propionate as a heat stabilizer was used, and 100 parts by weight of polymer (A-2-2) was used as the surface layer (Y). A 30 mm diameter single-screw extruder was used, and a three-type, three-layer T-die molding machine with a die width of 300 mm was used. The resin pellets for forming each layer were added from the resin supply hopper connected to each T-die for forming each layer, and the resin pellets were melted through the cylinder in the single-screw extruder set at 260 to 280 ° C. After that, a laminated film was obtained by extrusion molding from the T-die at a die temperature of 270 ° C. The thicknesses of the surface layer (Y), base layer (X), and surface layer (Y) were extruded so that Y / X / Y = 10 / 30 / 10 μm. The physical properties of the obtained laminated film are shown in Table 2.

[0111] [Example 2] A laminated film was obtained in the same manner as in Example 1, except that the copolymer (A-1-2) was used as the base layer (X) instead of the copolymer (A-1-1) used in Example 1. The physical properties of the obtained laminated film are shown in Table 2.

[0112] [Example 3] A laminated film was obtained in the same manner as in Example 1, except that the polymer (A-2-1) was used for the surface layer (Y) instead of the polymer (A-2-2) used in Example 1. The physical properties of the obtained laminated film are shown in Table 2.

[0113] [Example 4] A laminated film was obtained in the same manner as in Example 1, except that the copolymer (A-1-2) was used as the base layer (X) instead of the copolymer (A-1-1) used in Example 1, and the polymer (A-2-1) was used as the surface layer (Y) instead of the polymer (A-2-2) used in Example 1. The physical properties of the obtained laminated film are shown in Table 2.

[0114] [Example 5] A laminated film was obtained in the same manner as in Example 1, except that the base layer (X) was a composition of 50 parts by mass of copolymer (A-1-2) instead of copolymer (A-1-1) used in Example 1 and 50 parts by mass of Vistamaxx 6202 (Tm = 110 ° C, MFR (230 ° C, load 2.16 kgf) = 20 g / 10 min) manufactured by ExxonMobil Corporation as the propylene-based polymer (C-1), and the surface layer (Y) was a composition of 50 parts by mass of copolymer (A-1-2) instead of copolymer (A-1-1) used in Example 1. The physical properties of the obtained laminated film are shown in Table 2.

[0115] [Example 6] A laminated film was obtained in the same manner as in Example 1, except that the base layer (X) was a composition of 50 parts by mass of copolymer (A-1-2) instead of copolymer (A-1-1) used in Example 1 and 50 parts by mass of Prime Polypro F107BV (Tm = 160 ° C, MFR (230 ° C, load 2.16 kgf) = 7 g / 10 min) manufactured by Prime Polymer Co., Ltd. as the propylene-based polymer (C-2), and the surface layer (Y) was a composition of 50 parts by mass of copolymer (A-1-2) instead of copolymer (A-1-1) used in Example 1. The physical properties of the obtained laminated film are shown in Table 2.

[0116] [Example 7] A laminated film was obtained in the same manner as in Example 1, except that the base layer (X) was a composition of 20 parts by mass of 4-methyl-1-pentene-α-olefin copolymer (A-1-2) instead of copolymer (A-1-1) used in Example 1 and 80 parts by mass of Prime Polypro F107BV (Tm = 160°C, MFR (230°C, load 2.16 kgf) = 7 g / 10 min) manufactured by Prime Polymer Co., Ltd. as propylene polymer (C-1), and the surface layer (Y) was made of polymer (A-2-1) instead of polymer (A-2-2) used in Example 1. The physical properties of the obtained laminated film are shown in Table 2.

[0117] [Example 8] As the base layer (X), a composition of 5 parts by mass of copolymer (A-1-2) instead of copolymer (A-1-1) used in Example 1 and 95 parts by mass of Prime Polypro F107BV (Tm = 160 ° C, MFR (230 ° C, load 2.16 kgf) = 7 g / 10 min) manufactured by Prime Polymer Co., Ltd. was used as the propylene-based polymer (C-1), and as the surface layer (Y), polymer (A-2-1) was used instead of polymer (A-2-2) used in Example 1. A laminated film was obtained in the same manner as in Example 1. Various physical properties of the obtained laminated film are shown in Table 2.

[0118] [Comparative Example 1] A laminated film was obtained in the same manner as in Example 1, except that a propylene-based polymer (C-1) [Prime Polypro F107BV (Tm = 160 ° C, MFR (230 ° C, load 2.16 kgf) = 7 g / 10 min) manufactured by Prime Polymer Co., Ltd.] was used as the base layer (X) instead of the copolymer (A-1-1) used in Example 1, and a polymer (A-2-1) was used as the surface layer (Y) instead of the polymer (A-2-2) used in Example 1. The physical properties of the obtained laminated film are shown in Table 2.

[0119] Comparative Example 2 A single-layer film was obtained in the same manner as in Example 1, except that a single-layer film composed of 100 parts by mass of polymer (A-2-2) was used instead of the laminated film used in Example 1. The physical properties of the obtained single-layer film are shown in Table 2.

[0120] Comparative Example 3 A single-layer film was obtained in the same manner as in Example 1, except that a single-layer film composed of 100 parts by mass of copolymer (A-1-2) was used instead of the laminated film used in Example 1. The physical properties of the obtained single-layer film are shown in Table 2.

[0121] [Table 2]

Claims

1. The laminated sheet includes a substrate layer (X) and a surface layer (Y), the base layer (X) is an olefin polymer composition (M) containing 5 to 100 parts by mass of a 4-methyl-1-pentene copolymer (A-1) satisfying the following requirements (a) to (e), and 95 to 0 parts by mass of at least one olefin polymer (B) selected from a propylene polymer (C) and a butene polymer (E) (wherein the total of the components (A-1) and (B) is 100 parts by mass), A laminated film characterized in that the surface layer (Y) contains at least one thermoplastic resin selected from the group consisting of 4-methyl-1-pentene (co)polymer, polybutylene terephthalate, and polyethylene fluoride: [4-methyl-1-pentene copolymer (A-1)] (a) 97 to 60 mol % of structural units derived from 4-methyl-1-pentene and 3 to 40 mol % of structural units derived from at least one selected from ethylene or an α-olefin having 3 to 4 carbon atoms (wherein the total amount of structural units derived from 4-methyl-1-pentene and structural units derived from ethylene or an α-olefin having 3 to 4 carbon atoms is 100 mol %), (b) Intrinsic viscosity [η] measured in decalin at 135 ° C. is in the range of 0.5 to 5.0 dl / g; (c) The melting point (Tm) measured by DSC is 199°C or less, or is substantially unobservable. stomach, (d) a molecular weight distribution (Mw / Mn), which is the ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) measured by gel permeation chromatography (GPC), in the range of 1.0 to 3.5; and (e) Density is 825 to 860 kg / m 3 is in the range.

2. 2. The laminated film according to claim 1, wherein the thermoplastic resin is a 4-methyl-1-pentene (co)polymer (A-2) that satisfies the following requirements (g) to (i): [4-methyl-1-pentene (co)polymer (A-2)] (g) 100 to 90 mol % of structural units derived from 4-methyl-1-pentene and 0 to 10 mol % of structural units derived from at least one selected from α-olefins having 10 to 20 carbon atoms (excluding 4-methyl-1-pentene) (wherein the total amount of structural units derived from 4-methyl-1-pentene and structural units derived from α-olefins having 10 to 20 carbon atoms is 100 mol %), (h) a melting point (Tm) measured by DSC in the range of 200 to 250°C; and (i) Density is 820 to 850 kg / m ３ is in the range.

3. 3. The laminated film according to claim 1, wherein the olefin resin (B) constituting the olefin polymer composition (M) is a propylene polymer (C).

4. The laminate film according to claim 3, wherein the propylene polymer (C) contains 70 to 100 mol % of structural units derived from propylene and 30 to 0 mol % of structural units derived from at least one selected from ethylene or an α-olefin having 4 to 20 carbon atoms (wherein the total amount of structural units derived from propylene and structural units derived from ethylene or an α-olefin having 4 to 20 carbon atoms is taken as 100 mol %).

5. The laminated film has three or more layers consisting of a surface layer (Y), a base layer (X), and a surface layer (Y) in this order. The laminated film according to any one of claims 1 to 4, having a structure.

6. The laminate film according to any one of claims 1 to 5, wherein the laminate film is a laminate film obtained by a T-die film forming method.

7. A release film for producing a fiber-reinforced composite material, comprising the laminate film according to any one of claims 1 to 6.

8. A release film for producing a flexible printed circuit board, comprising the laminate film according to any one of claims 1 to 6.

9. A release film for semiconductor production, comprising the laminated film according to any one of claims 1 to 6.

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