JP2020006554A - Laminate film - Google Patents

Abstract

To improve the peelability and solvent resistance of a laminate film having a cured layer on an unoriented polyolefin film while maintaining a good appearance of it.SOLUTION: A laminate film has a cured layer of an active energy ray-curable composition containing a compound having an alkyl group having 8 or more carbon atoms on at least one side of an unoriented polyolefin film.SELECTED DRAWING: None

Description

  The present invention relates to a laminated film having a cured layer on an unstretched polyolefin film, and more particularly to a laminated film suitable as a base film of a release film, a protective film, or an adhesive film.

  A release film is used as a carrier film or a protective film of an adhesive layer used in a manufacturing process of precision electronic devices such as a ceramic capacitor, a hard disk drive, and a semiconductor device. Further, the release film is used as a carrier film for forming a green sheet, a photosensitive resin layer (photoresist layer) and the like.

  The release film is usually provided with a release layer for the purpose of improving the releasability.

  A silicone compound (release agent) is generally used for a release layer of a release film. However, when a silicone compound is used for an application related to precision electronic equipment, a low molecular weight compound contained in the release layer is used. There is a concern that the silicone compound migrates to the pressure-sensitive adhesive layer or the photosensitive resin layer and remains in the precision electronic device, causing troubles in the precision electronic device. When a silicone compound is used for the release film of the silicone pressure-sensitive adhesive layer, peeling failure may occur.

  Therefore, a release film using a non-silicone compound for the release layer is known, and it has been proposed to use a long-chain alkyl compound as the non-silicone compound (Patent Documents 1 to 5).

  On the other hand, a release film using an unstretched polypropylene film is known (Patent Document 6).

JP 2003-300283 A JP 2011-230289 A JP 2013-87239 A JP 2015-30795 A JP-A-2006-33173 JP 2012-167255 A

  An unstretched polyolefin film such as an unstretched polypropylene film has a relatively high elongation and is excellent in moldability, but on the other hand, has low heat resistance, and after a composition for forming a release layer is applied to the film. The film may be wrinkled or deformed in a high-temperature heating step such as drying and curing of the film to deteriorate the appearance of the film. If drying and curing are performed at a relatively low temperature to avoid this problem, the releasability and the solvent resistance may decrease.

  When the release property of the release layer is reduced, the release property between the release layer and the release layer such as an adhesive layer or a photosensitive resin layer laminated or superimposed on the release layer becomes poor, and the release layer is damaged. Sometimes.

  Further, when the solvent resistance of the release layer is low, the organic solvent contained in the coating composition for forming the peelable layer such as the adhesive layer or the photosensitive resin layer swells or dissolves the release layer surface. The peelability between the release layer and the layer to be peeled may become unstable.

  Accordingly, an object of the present invention is to improve peelability and solvent resistance while maintaining a good appearance of a laminated film in which a cured layer is laminated on an unstretched polyolefin film.

  In order to solve the above-mentioned problems, the inventors of the present invention have conducted intensive studies, and by using a cured layer of a specific active energy ray-curable composition, a thermal layer conventionally known as a release layer has been used. It has been found that even when formed at a relatively low temperature (for example, 110 ° C. or lower) as compared with the cured layer of the curable composition, good peelability and solvent resistance can be obtained. It has been found that good peelability and solvent resistance can be obtained while suppressing deformation and wrinkling of the unstretched polyolefin film having a relatively low.

That is, the above object has been achieved by the following inventions.
[1] A laminated film having a cured layer of an active energy ray-curable composition containing a compound having an alkyl group having 8 or more carbon atoms on at least one surface of an unstretched polyolefin film.
[2] The laminated film according to [1], wherein the compound having an alkyl group having 8 or more carbon atoms is a compound (α) containing an ethylenically unsaturated group and an alkyl group having 8 or more carbon atoms in a molecule. .
[3] The method according to [1] or [2], wherein the active energy ray-curable composition contains a compound (β) having an ethylenically unsaturated group in the molecule and having no alkyl group having 8 or more carbon atoms. The laminated film according to the above.
[4] The laminated film according to any one of [1] to [3], wherein the cured layer has a center line average roughness Ra of 10 nm or more.
[5] The laminated film according to any one of [1] to [4], wherein the haze value is 1.5% or more.
[6] The laminated film according to any one of [1] to [5], wherein the cured layer has a surface free energy of 20 to 35 mJ / m ² .
[7] A release film comprising the laminated film according to any one of [1] to [6].
[8] A release film for transfer, used for laminating a layer to be transferred on the cured layer of the laminated film according to any one of [1] to [6].
[9] An adhesive layer transfer film, wherein an adhesive layer is laminated on the cured layer of the laminated film according to any one of [1] to [6].
[10] An adhesive film, wherein an adhesive layer is laminated on the surface of the laminated film according to any one of [1] to [6] opposite to the cured layer.

  According to the present invention, it is possible to provide a laminated film having improved peelability and solvent resistance while maintaining a good appearance.

  The laminated film of the present invention has a cured layer of the active energy ray-curable composition on at least one surface of the unstretched polyolefin film. Such an active energy ray-curable composition contains a compound having an alkyl group having 8 or more carbon atoms.

  The active energy ray-curable composition in the present invention is a composition that is cured by irradiation with an active energy ray. Examples of such active energy rays include ultraviolet rays, visible rays, infrared rays, electron beams, α rays, β rays, and γ rays.

  The cured layer of the active energy ray-curable composition in the present invention is obtained, for example, by applying the composition onto a non-stretched polyolefin film, drying the composition, and then irradiating the composition with an active energy ray.

[Active energy ray curable composition]
The active energy ray-curable composition of the present invention contains a compound having an alkyl group having 8 or more carbon atoms. Hereinafter, an alkyl group having 8 or more carbon atoms may be referred to as a “long-chain alkyl group”, and a compound having an alkyl group having 8 or more carbon atoms may be referred to as a “long-chain alkyl compound”. The long-chain alkyl group includes a linear or branched alkyl group.

  The carbon number of the long-chain alkyl group in the long-chain alkyl compound is preferably 10 or more, more preferably 12 or more. Further, the carbon number of the long-chain alkyl group is preferably 30 or less, more preferably 28 or less, and particularly preferably 25 or less.

  The active energy ray-curable composition in the present invention contains a compound that is polymerized and cured by an active energy ray (hereinafter, a polymerizable compound). Examples of such a polymerizable compound include compounds (monomers and oligomers) having at least one ethylenically unsaturated group in the molecule. Here, examples of the ethylenically unsaturated group include an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group, an allyl group, and a vinyl group.

  The long-chain alkyl compound contained in the active energy ray-curable composition may or may not be a polymerizable compound, but is preferably a polymerizable compound. That is, the long-chain alkyl compound contained in the active energy ray-curable composition is a compound (α) containing an ethylenically unsaturated group and an alkyl group having 8 or more carbon atoms in the molecule (hereinafter referred to as “polymerizable long-chain Alkyl compound (α) ”). When the long-chain alkyl compound is a polymerizable long-chain alkyl compound (α), the releasability between the layer to be peeled and the cured layer and the solvent resistance are further improved. Hereinafter, the releasability between the layer to be peeled and the cured layer may be referred to as “the releasability of the cured layer”.

  In the following description, "... (meth) acrylate" is a general term for "... acrylate" and "... methacrylate".

  Examples of the polymerizable long-chain alkyl compound (α) include octyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, octadecyl (meth) acrylate, Nonadecyl (meth) acrylate, eicosyl (meth) acrylate and the like can be mentioned.

  In particular, the following polymerizable long-chain alkyl compound (α) is preferably used. Examples of such a compound include a (meth) acrylate compound (a) having at least one (meth) acryloyl group and a hydroxyl group in a molecule, and a polyisocyanate compound (b) having two or more isocyanate groups in a molecule. ) And a higher alcohol (c) having 8 to 30 carbon atoms.

  Examples of the (meth) acrylate compound (a) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, Glycerin mono (meth) acrylate, glycerin di (meth) acrylate, 2-hydroxy-3-acryloyloxypropyl methacrylate, 2- (meth) acryloyloxyethyl-2-hydroxyethylphthalic acid, 2-methacryloyloxyethyl-2-hydroxy Propyl phthalate, 2- (meth) acryloyloxyethyl-acid phosphate, epoxy (meth) acrylate, pentaerythritol mono (meth) acrylate, pentaerythritol di (meth) acryle Pentaerythritol tri (meth) acrylate, dipentaerythritol mono (meth) acrylate, dipentaerythritol di (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (Meth) acrylate, (Meth) acrylate having 2 to 30 alkyleneoxy groups (for example, ethyleneoxy group, propyleneoxy group, butyleneoxy group, etc.) in the molecule, and the like can be given.

  Among the above compounds, from the viewpoint of improving the peelability and solvent resistance of the cured layer, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, Hydroxybutyl (meth) acrylate and (meth) acrylate having 2 to 30 alkyleneoxy groups in the molecule are preferably used.

  Examples of the polyisocyanate compound (b) include hexamethylene diisocyanate, lysine diisocyanate, naphthalene diisocyanate, diphenylmethane diisocyanate, tolidine diisocyanate, tolylene diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene Diisocyanate compounds such as diisocyanate and hydrogenated xylylene diisocyanate, and further reacting these various diisocyanate compounds with water to obtain a biuret-type polyisocyanate compound or various diisocyanate compounds and a polyhydric alcohol such as trimethylolpropane. Adduct-type polyisocyanate compound obtained by Or those of various compounds of the multimer such as a known obtained allowed isocyanurating the like.

  Among the polyisocyanate compounds, compounds having a molecular weight of 50 to 500 are preferable, compounds having a molecular weight of 100 to 400 are more preferable, and compounds having a molecular weight of 130 to 300 are particularly preferable. For example, hexamethylene diisocyanate (molecular weight: 168) and diphenylmethane diisocyanate (molecular weight: 250) are exemplified as preferred compounds.

  Examples of the higher alcohol (c) include straight-chain higher alcohols such as octyl alcohol, decyl alcohol, lauryl alcohol, myristyl alcohol, cetanol, cetostearyl alcohol, stearyl alcohol, and behenyl alcohol. Examples of the saturated higher alcohol include oleyl alcohol, and examples of the branched higher alcohol include 2-hexyldecanol, 2-octyldodecanol, and 2-decyltetradodecanol.

  Commercial products can be used as the higher alcohol (c). For example, as a linear saturated higher alcohol, "CONOL (registered trademark)" 10WS, CONOL 1098, CONOL 1275, CONOL 20F, CONOL 20P, CONOL 1495, CONOL 1670, CONOL 1695, CONOL 30CK, CONOL 30OC, CONOL 30RC Connol 30F, Connol 30S, Connol 30SS, Connol 30T, Connol 2265, Connol 2280 (trade names of Nippon Rika Co., Ltd.), "Calcol (registered trademark)" 0898, Calcol 0880, Calcol 1098, Calcol 2098, Calcol 4098 , Calcol 6098, Calcol 8098, Calcol 200GD, Calcol 2475, Calcol 2474, Calcol 2473, Calcol 2463, Calcol 2455, Calcol 2450, Calcol 4250, Calcol 6870, Calcol 6850, Calcol 8688, Calcol 8665, Calcol 220-80 (trade name of Kao Corporation), and straight-chain unsaturated higher alcohols include "Licacol (registered trademark)". "60B, Ricacol 70B, Ricacol 75BJ, Ricacol 85BJ, Ricacoll 90B, Ricacoll 90BR, Ricacoll 90BHR, Ricacoll 110BJ," Angecol (registered trademark) "50A, Angecoll 60AN, Angecoll 70AN, Angecoll 80AN, Angecoll 85AN, Angecoll 90AN, Angecoll 90NR, Angecoll 90NHR (trade name of Nippon Rika Co., Ltd.), and branched higher alcohols such as "Engecol (registered trademark)" "160BR, Enujekoru 200A, (trade name of New Japan Chemical Co., Ltd.) Enujekoru 240A and the like.

  As described above, the long-chain alkyl compound contained in the active energy ray-curable composition may not be a polymerizable compound. Hereinafter, a long-chain alkyl compound that is not a polymerizable compound may be referred to as a non-polymerizable long-chain alkyl compound. Examples of the non-polymerizable long-chain alkyl compound include a long-chain alkyl group-containing polyvinyl resin, a long-chain alkyl group-containing alkyd resin, and a long-chain alkyl group-containing acrylic resin.

  The long-chain alkyl group-containing polyvinyl resin may be a polyvinyl alcohol polymer (including partially saponified polyvinyl acetate), an ethylene-vinyl alcohol polymer (including partially saponified ethylene-vinyl acetate copolymer) or a vinyl alcohol polymer. It can be synthesized by reacting an acrylic acid copolymer (including a partially saponified vinyl acetate-acrylic acid copolymer) with a long-chain alkyl group-containing isocyanate compound.

  Examples of the long-chain alkyl group-containing isocyanate compound include a monoisocyanate compound having a long-chain alkyl group. Specifically, octyl isocyanate, nonyl isocyanate, decyl isocyanate, dodecyl isocyanate, tetradecyl isocyanate, hexadecyl isocyanate, octadecyl isocyanate And the like.

  Examples of the long-chain alkyl group-containing alkyd resin include those obtained by modifying a condensate of a polybasic acid having a long-chain alkyl group and a polyhydric alcohol with a fatty oil or a fatty acid. Examples of polybasic acids include saturated polybasic acids such as phthalic anhydride, terephthalic acid, succinic acid, adipic acid and sebacic acid, and unsaturated polybasic acids such as maleic acid, maleic anhydride, fumaric acid, itaconic acid and citraconic anhydride. Other polybasic acids such as basic acid, cyclopentadiene-maleic anhydride adduct, terpene-maleic anhydride adduct, and rosin-maleic anhydride adduct. Examples of polyhydric alcohols include dihydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, and tetramethylene glycol; trihydric alcohols such as glycerin and trimethylolpropane; diglycerin, triglycerin, and pentaerythritol. And dihydric alcohols such as dipentaerythritol, mannitol and sorbitol. As a denaturing agent, soybean oil, linseed oil, tung oil, castor oil, dehydrated castor oil, coconut oil, and their fatty acids, stearic acid, oleic acid, linoleic acid, linoleic acid, eleostearic acid, ricinoleic acid, dehydrated Fats and oils and fatty acids such as ricinoleic acid, natural resins such as rosin, kovar, amber, and shellac, and synthetic resins such as ester gum, phenol resin, urea resin, and melamine resin.

  As the long-chain alkyl group-containing acrylic resin, acrylic acid monomers or methacrylic acid monomers having a long-chain alkyl group, for example, octyl acrylate, octyl methacrylate, lauryl acrylate, lauryl methacrylate, octadecyl acrylate, octadecyl methacrylate, and the like And a homopolymer or a copolymer of the above.

  Other monomers used in the above copolymer include, for example, acrylic acid, methacrylic acid, acrylamide, methacrylamide, styrene and the like.

  The above-mentioned non-polymerizable long-chain alkyl compounds are commercially available and can be used. Commercially available products include “K-256”, “N-137”, “P-677”, and “Q-472” of Resem Series manufactured by Chukyo Yushi Co., Ltd., and “RA” of Asio Resin Series manufactured by Asio Sangyo Co., Ltd. -80 "," RA-95H "," RA-585S ", and" HT "," 1050 "," 1010 "," 1070 "," 406 "of the Piroyl series manufactured by Lion Specialty Chemicals Co., Ltd. Examples include "ZF-15" and "ZF-15H" manufactured by Japan Vineyard Poval, "Epomin (registered trademark)" and "RP-20" manufactured by Nippon Shokubai.

  When the active energy ray-curable composition contains only a non-polymerizable long-chain alkyl compound as a long-chain alkyl compound, a compound having an ethylenically unsaturated group in the molecule and having no alkyl group having 8 or more carbon atoms (Β) (hereinafter sometimes referred to as “polymerizable compound (β)”). That is, the polymerizable compound (β) is a polymerizable compound having no long-chain alkyl group. Details of the polymerizable compound (β) will be described later.

  In the active energy ray-curable composition, a polymerizable long-chain alkyl compound (α) and a non-polymerizable long-chain alkyl compound can be used in combination, or a polymerizable long-chain alkyl compound (α) and a polymerizable compound can be used. (Β) can be used in combination, or a polymerizable long-chain alkyl compound (α), a non-polymerizable long-chain alkyl compound and a polymerizable compound (β) can be used in combination.

In particular, the active energy ray-curable composition preferably uses a polymerizable long-chain alkyl compound (α) and a polymerizable compound (β) in combination. Thereby, the releasability and solvent resistance of the cured layer are further improved. Examples of the polymerizable compound (β) include methyl (meth) acrylate, ethyldiethylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, and methoxytriethylene. Glycol (meth) acrylate, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (Meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, dipropylene glycol di (meth) Acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, glycerin propoxy tri (meth) ) Acrylate, pentaerythritol mono (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol mono (meth) acrylate, dipentaerythritol di (meth) ) Acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) Acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tripentaerythritol tri (meth) acrylate, tripentaerythritol hexa (meth) acrylate, tripentaerythritol octa (meth) acrylate, pentaerythritol tri Examples include (meth) acrylate hexamethylene diisocyanate urethane pre-oligomer, pentaerythritol tri (meth) acrylate-toluene diisocyanate urethane oligomer, and pentaerythritol tri (meth) acrylate-isophorone diisocyanate urethane oligomer.

  Among the above polymerizable compounds (β), a compound having 2 to 10 ethylenically unsaturated groups in a molecule is preferable, and a compound having 3 to 8 ethylenically unsaturated groups in a molecule is more preferable. In particular, compounds having 4 to 6 ethylenically unsaturated groups in the molecule are preferred. By including such a polymerizable compound (β), the hardness of the cured layer is easily increased, and as a result, the solvent resistance is easily improved.

  The content of the long-chain alkyl compound (the total amount of the polymerizable long-chain alkyl compound (α) and the non-polymerizable long-chain alkyl compound) in the active energy ray-curable composition is from the viewpoint of improving the releasability of the cured layer. It is preferably at least 3% by mass, more preferably at least 5% by mass, particularly preferably at least 10% by mass, based on 100% by mass of the total solid content of the active energy ray-curable composition. On the other hand, if the content of the long-chain alkyl compound is too large, the strength (hardness) of the cured layer may be reduced and the solvent resistance may be reduced. Therefore, the content of the long-chain alkyl compound is preferably 70% by mass or less. , 50% by mass or less, more preferably 30% by mass or less.

  The content of the polymerizable compound (β) in the active energy ray-curable composition is determined from the viewpoint of increasing the strength (hardness) of the cured layer and improving the solvent resistance, from the viewpoint of improving the solvent resistance. It is preferably at least 10% by mass, more preferably at least 20% by mass, particularly preferably at least 30% by mass with respect to 100% by mass. On the other hand, if the content of the polymerizable compound (β) is too large, the releasability of the cured layer may decrease. Therefore, the content of the polymerizable compound (β) is preferably 90% by mass or less, and more preferably 80% by mass. The content is more preferably, and particularly preferably 70% by mass or less.

  The active energy ray-curable composition preferably further contains a photopolymerization initiator. Specific examples of such a photopolymerization initiator include, for example, acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, benzophenone, 2-chlorobenzophenone, 4,4′-dichlorobenzophenone, 4,4′-bisdiethylaminobenzophenone, Michler's ketone, benzyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, methylbenzoyl formate, p-isopropyl-α-hydroxyisobutylphenone, α-hydroxyisobutylphenone, 2, Carbonyl compounds such as 2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenyl ketone, tetramethylthiuram monosulfide, Sulfur compounds such as lamethylthiuram disulfide, thioxanthone, 2-chlorothioxanthone and 2-methylthioxanthone can be used. These photopolymerization initiators may be used alone or in combination of two or more.

  In addition, photopolymerization initiators are generally commercially available, and they can be used. For example, “Irgacure (registered trademark)” 184, Irgacure 907, Irgacure 379, Irgacure 819, Irgacure 127, Irgacure 500, Irgacure 754, Irgacure 250, Irgacure 1800, Irgacure 1870, Elgac O manufactured by Ciba Specialty Chemicals Co., Ltd. , "DAROCUR (registered trademark)" TPO, DAROCUR1173, etc., Japan Siber Hegner Co., Ltd. "Speedcure (registered trademark)" MBB, SpeedcurePBZ, SpeedcureITX, SpeedcureCTX, SpeedcureEDB, "Esacure (registered trademark)" ONE, Esacure KIP150, Esacure "KAYACURE" manufactured by Nippon Kayaku Co., Ltd. (Registered trademark) "DETX-S, KAYACURE CTX, KAYACURE BMS, KAYACURE DMBI, and the like.

  The content of the photopolymerization initiator is suitably in the range of 0.1 to 15% by mass and preferably in the range of 0.5 to 10% by mass based on 100% by mass of the total solid content of the active energy ray-curable composition. Is preferred.

  The active energy ray-curable composition can further contain a binder resin. Examples of the binder resin include a polyurethane resin, an acrylic resin, a polyester resin, and an elastomer resin. Here, the binder resin is a resin containing no long-chain alkyl group.

  Further, the active energy ray-curable composition can contain particles, an antistatic agent, a colorant, and the like.

  It is preferable that the active energy ray-curable composition does not contain any silicone-based compound. However, when the active energy ray-curable composition contains a silicone-based compound, the active energy ray-curable composition has a content of 5% by mass based on 100% by mass of the total solid content of the active energy ray-curable composition. Is preferably 3% by mass or less, more preferably 1% by mass or less.

  Here, the silicone-based compound refers to a silicone-based compound conventionally generally known as a silicone-based release agent. Silicone is a polymer having a main chain formed by alternately bonding silicon having an organic group (for example, an alkyl group or a phenyl group) and oxygen. For example, a silicone compound having dimethylpolysiloxane as a basic skeleton is well known.

[Curing layer]
The cured layer of the active energy ray-curable composition according to the present invention is obtained, for example, by applying the composition onto a non-stretched polyolefin film, drying the composition, and then irradiating with an active energy ray to cure the composition.

  As a method for applying the active energy ray-curable composition, a wet coating method is preferably used. Examples of such a wet coating method include a reverse coating method, a spray coating method, a bar coating method, a gravure coating method, a rod coating method, a die coating method, a spin coating method, an extrusion coating method, and a curtain coating method.

  The drying of the active energy ray-curable composition applied on the unstretched polyolefin film is preferably performed at a relatively low temperature. For example, the maximum temperature in the drying step is preferably 110 ° C. or lower, more preferably 100 ° C. or lower, further preferably 90 ° C. or lower, and particularly preferably 80 ° C. or lower. By drying at a relatively low temperature in this manner, deformation and wrinkling of the unstretched polyolefin film can be suppressed. The cured layer of the active energy ray-curable composition according to the present invention can obtain good releasability even when dried at a relatively low temperature as described above.

  Active energy rays for curing the active energy ray-curable composition include ultraviolet rays, visible light rays, infrared rays, electron rays, α rays, β rays, γ rays, and the like. Among these active energy rays, ultraviolet rays and electron beams are preferable, and ultraviolet rays are particularly preferably used.

  The light source for irradiating ultraviolet rays is not particularly limited, and for example, an ultraviolet fluorescent lamp, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, and the like can be used. . Further, an ArF excimer laser, a KrF excimer laser, an excimer lamp, synchrotron radiation, or the like can be used. Among these, an ultra-high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc lamp, a xenon lamp, and a metal halide lamp are preferably used. In addition, it is preferable to perform irradiation in an atmosphere having a low oxygen concentration, for example, in an atmosphere having an oxygen concentration of 500 ppm or less when irradiating ultraviolet rays, because curing can be efficiently performed.

Irradiation light amount of the ultraviolet rays is preferably from 50 mJ / cm ² or more, 100 mJ / cm ² or more, and particularly 150 mJ / cm ² or more. Further, the irradiation light amount of the ultraviolet rays is preferably 2000 mJ / cm ² or less, and more preferably 1000 mJ / cm ² or less.

  The cured layer in the invention preferably functions as a release layer, and preferably has good releasability of the layer to be peeled or laminated on the cured layer. That is, it is preferable that the peeling force between the cured layer and the layer to be peeled (hereinafter, sometimes referred to as “the peeling force of the cured layer”) is relatively small.

  The peeling force of the cured layer can be represented by, for example, the peeling force of the pressure-sensitive adhesive tape to the cured layer. Specifically, it can be represented by a peeling force when the adhesive tape is peeled to 180 ° after the adhesive tape is stuck to the surface of the cured layer and the adhesive tape is peeled off at room temperature (23 ± 2 ° C.) for 24 hours.

  The peeling force of the cured layer is preferably 1.5 N / 50 mm or less, more preferably 1.0 N / 50 mm or less, and particularly preferably 0.8 N / 50 mm or less, from the viewpoint of smoothly peeling the layer to be peeled. On the other hand, if the peeling force is excessively small, the layer to be peeled may be peeled off or lifted up in steps other than the peeling step, so the peeling force is preferably 0.1 N / 50 mm or more, more preferably 0.2 N / 50 mm or more. 0.3 N / 50 mm or more is particularly preferable.

  The thickness of the cured layer is preferably 10 nm or more, more preferably 30 nm or more, and particularly preferably 50 nm or more, from the viewpoint of obtaining good peelability. On the other hand, if the thickness of the cured layer is too large, deformation and wrinkles are likely to occur in the unstretched polyolefin film. Therefore, the thickness of the cured layer is preferably 1,000 nm or less, more preferably 500 nm or less, and particularly preferably 300 nm or less.

The surface free energy of the cured layer is 20 to 35 mJ / m ² from the viewpoint of ensuring good coatability of the layer to be peeled or laminated on the cured layer of the laminated film and reducing the peeling force. Preferably, it is 21 to 32 mJ / m ² , more preferably 22 to 30 mJ / m ² . If the surface free energy of the cured layer is less than 20 mJ / m ² , the coatability of the layer to be peeled may be deteriorated, while if it is more than 35 mJ / m ² , the peeling force may be increased.

  By using a cured layer of the active energy ray-curable composition as the cured layer, preferably, by causing the active energy ray-curable composition to contain a polymerizable long-chain alkyl compound (α), the surface free energy is reduced as described above. In the range.

  Here, the surface free energy can be measured using a contact angle meter, for example, “Drop Master DM501” manufactured by Kyowa Interface Science Co., Ltd. Details will be described later.

  The center line average roughness Ra of the cured layer is preferably 10 nm or more, more preferably 20 nm or more, and particularly preferably 30 nm or more, from the viewpoint of roll transportability and windability in the production process of the laminated film and the lamination process of the layer to be peeled. preferable. If the center line average roughness Ra of the cured layer is excessively large, the coatability of the transfer layer may be deteriorated. Therefore, the thickness is preferably 500 nm or less, more preferably 400 nm or less, and particularly preferably 300 nm or less.

[Unstretched polyolefin film]
Examples of the polyolefin constituting the unstretched polyolefin film in the present invention include polyethylene, polypropylene, and a mixture thereof.

  Here, the polyethylene includes a homopolymer of ethylene and a copolymer of ethylene and another olefin. In addition, polypropylene includes homopolymers of propylene and copolymers of propylene with other olefins.

  Examples of the other olefin include ethylene, propylene, butene, pentene, hexene, heptene, octene, nonene, and decene. Among them, ethylene, propylene and butene are preferred.

  The mixing ratio of the other olefin in the copolymer of ethylene or propylene and the other olefin is preferably 40% by mass or less based on the total mass of ethylene or propylene as the monomer and the other olefin, It is more preferably at most 30% by mass, particularly preferably at most 20% by mass.

  Examples of the polyethylene include high-density polyethylene (HDPE), low-density polyethylene (LDPE), and linear low-density polyethylene (L-LDPE).

  The unstretched polyolefin film in the invention preferably contains at least polypropylene. Specifically, it is preferable to include at least one selected from the group consisting of a propylene homopolymer and a copolymer of propylene and another olefin.

  Examples of the copolymer of propylene and another olefin include a copolymer of propylene and ethylene, a copolymer of propylene and butene, and a copolymer of propylene, ethylene and butene. These copolymers may be random copolymers or block copolymers. The mixing ratio of the other olefin in the copolymer is preferably 40% by mass or less, more preferably 30% by mass or less, and more preferably 20% by mass or less based on the total mass of propylene as a monomer and the other olefin. Is particularly preferred.

  In addition, the unstretched polyolefin film can include a mixture of polypropylene and polyethylene. The content ratio of polyethylene in the mixture of polypropylene and polyethylene is preferably 40% by mass or less, more preferably 30% by mass or less, and particularly preferably 20% by mass or less, based on the total mass of polypropylene and polyethylene.

  The non-stretched polyolefin film in the present invention may have a single-layer structure of polyolefin or a multilayer structure of polyolefin.

  Examples of the multilayer laminated structure include a two-layer laminated structure of A layer / B layer, and a three-layer laminated structure of A layer / B layer / A layer or A layer / B layer / C layer. Here, the A layer, the B layer, and the C layer have different compositions.

  The unstretched polyolefin film is formed by cooling and solidifying the resin extruded into a sheet by a melt extruder with a casting roll.

  On the other hand, a generally known stretched film is formed by stretching in a uniaxial direction or a biaxial direction after cooling and solidifying.

  The unstretched polyolefin film in the present invention is an unstretched film formed without performing stretching after cooling and solidifying.

  The non-stretched polyolefin film can contain particles, pigments, colorants, antistatic agents, ultraviolet absorbers, antioxidants, heat stabilizers, chlorine scavengers, and the like.

  The thickness of the unstretched polyolefin film is preferably 20 μm or more, more preferably 30 μm or more, and particularly preferably 40 μm or more, from the viewpoint of suppressing the occurrence of deformation and wrinkles in the step of laminating the cured layer. Further, the thickness is preferably 200 μm or less, more preferably 150 μm or less, and particularly preferably 100 μm or less.

  Unstretched polyolefin films are generally commercially available, and they can be used. For example, from Toray Film Processing Co., Ltd., an unstretched film of a propylene homopolymer and an unstretched film of a copolymer of propylene and another olefin are available from “Trefane (registered trademark)” NO3301, NO3501, NO9141, NO3951, It is commercially available and can be used as NO9405S, NO9407, NO3701J, NO3721, NOZK93KM, NOZK93FM, NOZK99S, NOZK207, and NOZK100.

[Laminated film]
The laminated film of the present invention has a cured layer of the active energy ray-curable composition on at least one surface of the unstretched polyolefin film. The cured layer may be provided on only one side of the unstretched polyolefin film, or may be provided on both sides.

  When the laminated film of the present invention is applied as a release film, since the release film is finally peeled and removed, the release film can be relatively easily identified so as to prevent forgetting to release the release film. Is preferred. From the viewpoint of enhancing the distinguishability of the laminated film (release film), the haze value of the laminated film is preferably 1.5% or more, more preferably 2.5% or more, and more preferably 3.5% or more. Is particularly preferred. The upper limit is not particularly limited, but is about 50%.

  The haze value of the laminated film can be adjusted, for example, by controlling the haze value of an unstretched polyolefin film. That is, it is preferable to use an unstretched polyolefin film having a haze value of 1.5% or more, more preferably an unstretched polyolefin film having a haze value of 2.5% or more, and a haze value of 3.5%. It is particularly preferable to use the unstretched polyolefin film described above.

  The laminated film of the present invention has good peelability and solvent resistance.

  Here, the releasability means the releasability between a cured layer and a layer to be peeled such as an adhesive layer or a photosensitive resin layer laminated or superposed on the cured layer of the laminated film.

  Further, good solvent resistance means that the cured layer is unlikely to dissolve or swell in an organic solvent. When the solvent resistance of the cured layer is low, the organic solvent contained in the coating composition for forming the layer to be peeled such as the adhesive layer or the photosensitive resin layer swells or dissolves the cured layer surface to release the cured layer. However, such a problem can be improved by improving the solvent resistance of the cured layer.

  Furthermore, the laminated film of the present invention can be expected to improve moldability.

[Application example]
The laminated film of the present invention is suitable as a release film. For example, a release film for transfer used for laminating layers to be peeled such as an adhesive layer, a photosensitive resin layer, a ceramic layer, and an epoxy sealing layer, and transferring and bonding this layer to another adherend. It is suitable as. In particular, it is suitable as a release film for transferring an adhesive layer in which the layer to be peeled is an adhesive layer. In this case, the cured layer of the laminated film functions as a release layer.

  In the above application example, for example, a layer to be peeled (transferred layer) as described above is laminated on a cured layer (release layer) of a laminated film to obtain a transfer film. When the layer to be peeled (transferred layer) is an adhesive layer, an adhesive layer transfer film is obtained. The laminated film (release film) is peeled off after the transfer layer (transfer layer) of the transfer film is transferred to and adhered to another adherend or simultaneously with the transfer. At this time, it is preferable that the laminated film (release film) is easily peeled off, and the laminated film of the present invention is preferable because of good peelability.

  That is, the present invention provides a release film comprising the laminated film of the present invention.

  In other words, the present invention provides, "at least one surface of the unstretched polyolefin film has a release layer composed of a cured layer of an active energy ray-curable composition containing a compound having an alkyl group having 8 or more carbon atoms, Release film ".

  The present invention also provides a transfer release film used for laminating a layer to be peeled (transferred layer) on the cured layer of the laminated film of the present invention. Here, the layer to be peeled (transferred layer) is preferably an adhesive layer.

  Further, the laminated film of the present invention is suitable as a base film of an adhesive film. In this case, the cured layer of the laminated film functions as a release layer. In such an application example, an adhesive layer is laminated on the surface of the laminated film opposite to the cured layer to obtain an adhesive film. Since this adhesive film is usually produced on a roll-to-roll basis and supplied by a roll, the cured layer of the laminated film is opposed to and adheres to the adhesive layer. When using the pressure-sensitive adhesive film roll, it is necessary to smoothly unwind the film, and the laminated film of the present invention is suitable because of good releasability from the pressure-sensitive adhesive layer.

  That is, the present invention provides a pressure-sensitive adhesive film in which, in the laminated film of the present invention having a cured layer only on one surface of an unstretched polyolefin film, a pressure-sensitive adhesive layer is laminated on the surface opposite to the cured layer of the laminated film. .

  Further, the laminated film of the present invention is suitable as a protective film for an adhesive film or a photosensitive resin film. In this case, the cured layer of the laminated film functions as a release layer. In such an application example, the adhesive layer of the adhesive film or the photosensitive resin layer of the photosensitive resin film and the cured layer of the laminated film of the present invention are overlapped so as to face each other. It is preferable that the protective film (laminated film of the present invention) can be easily peeled off when its function is completed, and that the laminated film of the present invention has good releasability from the adhesive layer or the photosensitive resin layer. Is preferred.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.
[Measurement method and evaluation method]
(1) Measurement of Haze Value of Laminated Film and Unstretched Polyolefin Film Based on JIS K 7136 (2000), the haze value of the laminated film was measured using a turbidity meter “NDH-4000” manufactured by Nippon Denshoku Industries Co., Ltd. It was measured. At the time of measurement, it was arranged such that light was incident on the surface of the cured layer of the laminated film.

  Further, the haze value of the unstretched polyolefin film was also measured based on JIS K 7136 (2000) using a turbidity meter “NDH-4000” manufactured by Nippon Denshoku Industries Co., Ltd.

(2) Measurement of Center Line Average Roughness Ra of Laminated Film and Unstretched Polyolefin Film Based on JIS B0601 (1982), using a stylus type surface roughness measuring instrument SE-3400 (manufactured by Kosaka Laboratory Co., Ltd.). It was measured.

<Measurement conditions>
・ Feeding speed: 0.5mm / sec
・ Evaluation length: 8mm
A cutoff value λc;
When Ra is 20 nm or less, λc = 0.08 mm
When Ra is larger than 20 nm and 100 nm or less, λc = 0.25 mm
When Ra is larger than 100 nm and equal to or smaller than 2000 nm, λc = 0.8 mm
In the measurement under the above measurement conditions, first, measurement is performed with a cut-off value λc = 0.8 mm. As a result, when Ra is larger than 100 nm, the Ra is adopted. On the other hand, as a result of the above measurement, when Ra is 100 nm or less, re-measurement is performed at λc = 0.25 mm. As a result, when Ra is larger than 20 nm, the Ra is adopted. On the other hand, as a result of the re-measurement, when Ra is 20 nm or less, the measurement is performed at λc = 0.08 mm, and the Ra is adopted.

(3) Measurement of surface free energy of hardened layer Water, diiodomethane, and 1-bromonaphthalene were used as three kinds of liquids whose values of surface free energy and its components (dispersion force, polar force, hydrogen bonding force) were known. The contact angle of each liquid on the cured layer was measured with a contact angle meter DropMaster DM501 (manufactured by Kyowa Interface Science Co., Ltd.) at 23 ° C. and 65% RH. The measurement was performed five times on one measurement surface, and the average value was defined as the contact angle (θ). From the value of this contact angle (θ) and the value of a known value of each liquid (Method IV by Panzer (described in Journal of the Adhesion Society of Japan, Vol. 15, No. 3, page 96), introduced from the Kitazaki-Hata equation. The value of each component was calculated using the following equation.

(ΓSd · γLd) 1/2 + (γSp · γLp) 1/2 + (γSh · γLh) 1/2 = γL (1 + cosθ) / 2
Here, γLd, γLp, and γLh represent the respective components of the dispersion force, the polar force, and the hydrogen bonding force of the measurement solution, θ represents the contact angle of the measurement solution on the measurement surface, and γSd, γSp, γSh represents the value of each component of the dispersing force, polar force, and hydrogen bonding force on the surface of the cured layer, and γL represents the surface energy of each liquid. By solving the simultaneous equations obtained by substituting the known value and θ into the above equation, the values of the three components on the measurement surface (cured layer surface) were obtained.

  As shown in the following equation, the sum of the determined value of the dispersive force component, the value of the polar force component, and the value of the hydrogen bond force component was defined as the value of the surface free energy (E).

E = γSd + γSp + γSh
(4) Measurement of Peeling Force of Cured Layer The adhesive layer of the acrylic pressure-sensitive adhesive tape (“No. 31B” manufactured by Nitto Denko Corporation) is moved back and forth once while pressing the pressure-sensitive adhesive surface of the laminated film with a rubber roller having its own weight of 5 kg. After being left at room temperature (23 ± 2 ° C.) for 24 hours, the peeling force when the adhesive tape side was peeled to 180 ° at a speed of 300 mm / min was measured by a tensile tester.

(5) Evaluation of Solvent Resistance of Cured Layer Using methyl ethyl ketone (MEK), toluene and ethyl acetate as organic solvents, the solvent resistance to each organic solvent was evaluated in the following manner.

The surface of the cured layer of the laminated film was rubbed five times with a cotton swab soaked in the organic solvent, and the state of the cured layer was visually observed and evaluated according to the following criteria.
A: When the cured layer does not change with any of the above three solvents.
B: When the above three solvents include a solvent for whitening the cured layer.
C: A case where a solvent that disappears the cured layer is included in the above three types of solvents.

(6) Thickness of Each Layer A sample for observing the cross section of the laminated film was subjected to the FIB method using a microsampling system (FB-2000A manufactured by Hitachi) (specifically, “Polymer Surface Processing Science” (Akira Iwamori) p. 118-119). The cross section of the sample for cross section observation was observed with a transmission electron microscope (H-9000UHRII manufactured by Hitachi, Ltd.) at an acceleration voltage of 300 kV, and the thickness of the unstretched polyolefin film and the cured layer were measured.

(7) Evaluation of appearance of laminated film The appearance of the laminated film was visually observed and evaluated according to the following criteria.
A: No wrinkles or deformations are observed in the laminated film.
B: Wrinkles or deformation are slightly observed in the laminated film.
C: Wrinkles or deformation are observed in the laminated film.

(8) Discrimination property of laminated film One of the separators of the acrylic pressure-sensitive adhesive sheet (“OCA (registered trademark)” 8146-2) of 3M Co., Ltd. was peeled off, and the cured layer of the laminated film produced in Examples and Comparative Examples was removed. A test piece was prepared by bonding. Next, this test piece was allowed to stand on a table with the laminated film facing upward, and visually observed under 40 W three-wavelength fluorescence installed at a position 50 cm high from the test piece, and evaluated according to the following criteria.
A: The laminated film can be easily identified.
B: The laminated film can be identified.
C: The laminated film cannot be identified.

[Unstretched polyolefin film]
The following unstretched polypropylene film was prepared.
<Film 1>
"Trefane (registered trademark)" NO3721 from Toray Film Processing Co., Ltd .; thickness: 70 μm, haze value: 26.1%, center line average roughness Ra: 195 nm.
<Film 2>
Toray Film Processing Co., Ltd. “Trefane (registered trademark)” NO3701J; thickness: 40 μm, haze value: 24.3%, center line average roughness Ra: 237 nm.
<Film 3>
Toray Film Processing Co., Ltd. “Trefane (registered trademark)” NO3301; thickness: 50 μm, haze value: 4.2%, center line average roughness Ra: 63 nm.
<Film 4>
Toray Film Processing Co., Ltd. “Trefane (registered trademark)” NO3501; thickness: 60 μm, haze value: 3.0%, center line average roughness Ra: 47 nm.

[Example 1]
The following active energy ray-curable composition p1 is applied to the corona-treated surface of the film 1 with a gravure coater, dried at a maximum temperature of 70 ° C., and irradiated with ultraviolet rays at 300 mJ / cm ² to be cured to form a cured layer. A laminated film was produced. The thickness of the cured layer was 200 nm.

<Active energy ray-curable composition p1>
25 parts by mass of the polymerizable long-chain alkyl compound (α1) synthesized as described below, 75 parts by mass of dipentaerythritol hexaacrylate (trade name “DPHA” of Daicel Cytec Co., Ltd.) as the polymerizable compound (β), and photopolymerization An initiator (Irgacure 184 manufactured by Ciba Specialty Chemicals Co., Ltd.) was charged in an amount of 10 parts by mass, and the mixture was heated to 100 ° C. and mixed for 1 hour to obtain an active energy ray-curable composition. This composition was adjusted to a solid content concentration of 4% by mass with a mixed solvent of toluene and isopropyl alcohol (toluene: IPA = 3: 1 (mass ratio)) to prepare a composition.

<Synthesis of polymerizable long-chain alkyl compound (α1)>
In a flask equipped with a stirrer and a thermometer, 2-hydroxyethyl acrylate (100 parts by mass of "BHEA" of Nippon Shokubai Co., Ltd.) as a (meth) acrylate compound having a hydroxyl group (a), and a polyisocyanate compound (b) 240 parts by mass of diphenylmethane diisocyanate (“Millionate (registered trademark) MT” of Nippon Polyurethane Co., Ltd.) and 26 parts by mass of stearyl alcohol (“CONOL 30SS” of Shin Nippon Rika Co., Ltd.) as the higher alcohol (c) The reaction was charged, heated to 100 ° C., and kept at the temperature for 7 hours for reaction. IR measurement confirmed that the isocyanate group had disappeared, and the reaction was terminated.

[Example 2]
A laminated film was produced in the same manner as in Example 1, except that the composition was changed to the following active energy ray-curable composition p2.

<Active energy ray-curable composition p2>
20 parts by mass of the polymerizable long-chain alkyl compound (α2) synthesized below, 80 parts by mass of dipentaerythritol hexaacrylate (trade name “DPHA” of Daicel Cytec Co., Ltd.) as the polymerizable compound (β), and photopolymerization An initiator (Irgacure 184 manufactured by Ciba Specialty Chemicals Co., Ltd.) was charged in an amount of 10 parts by mass, and the mixture was heated to 100 ° C. and mixed for 1 hour to obtain an active energy ray-curable composition. This composition was adjusted to a solid concentration of 4% by mass with a mixed solvent of toluene and isopropyl alcohol (toluene: IPA = 3: 1 (mass ratio)) to prepare a coating solution.

<Synthesis of polymerizable long-chain alkyl compound (α2)>
In a flask equipped with a stirrer and a thermometer, 2-hydroxyethyl acrylate (100 parts by mass of "BHEA" of Nippon Shokubai Co., Ltd.) as a (meth) acrylate compound having a hydroxyl group (a), and a polyisocyanate compound (b) 86 parts by mass of hexamethylene diisocyanate (trade name “HDI” of Nippon Polyurethane Co., Ltd.) and 46 parts by mass of stearyl alcohol (“Conol 30SS” of Shin Nippon Rika Co., Ltd.) as a higher alcohol (c) were charged at 100 ° C. The mixture was heated for 7 hours and reacted. After IR measurement, it was confirmed that the isocyanate group had disappeared, and the reaction was terminated.

[Example 3]
A laminated film was produced in the same manner as in Example 1, except that the following active energy ray-curable composition p3 was used.

<Active energy ray-curable composition p3>
13 parts by mass of a non-polymerizable long-chain alkyl compound synthesized below, 60 parts by mass of urethane acrylate (“UA-306T” manufactured by Kyoeisha Chemical) as a polymerizable compound (β), and 27 parts by mass of tricyclodecane dimethanol acrylate 7 mass of a photopolymerization initiator (Irgacure 184 manufactured by Ciba Specialty Chemicals Co., Ltd.) was adjusted to a solid concentration of 4% by mass with a mixed solvent of toluene and isopropyl alcohol (toluene: IPA = 3: 1 (mass ratio)). To prepare a coating solution.

<Synthesis of non-polymerizable long-chain alkyl compound>
To a four-necked flask equipped with a stirrer, a nitrogen inlet tube, a cooling tube and a rubber septum, 50 parts by mass of octadecyl acrylate and 1.2 parts by mass of 2,2'-bipyridine were further added, and the system was purged with nitrogen. did. Under a nitrogen stream, 0.5 parts by mass of copper bromide was added, the reaction system was heated to 90 ° C., 0.6 parts by mass of a polymerization initiator (ethyl 2-bromoisobutyrate) was added, and polymerization was started. The polymerization was carried out at 90 ° C. for 10 hours under a nitrogen stream without the addition of water. After confirming that the polymerization rate was 85% by weight or more, 33 parts by mass of 2-ethylhexyl acrylate was added from Rubber Cebutam and heated at 110 ° C for 20 hours.

  Thus, an AB type diblock polymer comprising an octadecyl acrylate polymer block and a 2-ethylhexyl acrylate polymer block was obtained. This was heated to 60 ° C. and centrifuged at 8,000 g for 30 minutes to obtain a supernatant polymer. To 50 parts by mass of this polymer was added 10 parts by mass of a sulfonic acid type ion exchange resin, and the mixture was stirred at 100 ° C. for 1 hour, and the ion exchange resin was removed by filtration. A compound (polymer) was obtained.

[Comparative Example 1]
The following thermosetting composition p4 is applied to the corona-treated surface of the film 1 with a gravure coater, dried at a maximum temperature of 90 ° C., and then heat-cured at a maximum temperature of 160 ° C. to form a cured layer to form a laminated film. did. The thickness of the cured layer was 200 nm.

<Thermosetting composition p4>
10 parts by mass of a long-chain alkyl compound (“Pyroyl” 1050, manufactured by Lion Specialty Chemicals Co., Ltd.) in terms of solids, and a melamine crosslinking agent (“Uban” 28-60, manufactured by Mitsui Chemicals, Inc.) in terms of solids. And 25 parts by mass of p-toluenesulfonic acid ("TAYCACURE" AC-707 from Teica Co., Ltd., AC-707) in terms of solid content, and 2.0 parts by mass of a mixed solvent (toluene: methyl ethyl ketone: cyclohexanone = 45:45:10 ( (Mass ratio)) to prepare a solid content concentration of 2.0% by mass.

[Comparative Example 2]
In Comparative Example 1, a cured film was formed in the same manner as in Comparative Example 1 except that the film was dried at a maximum temperature of 90 ° C. and then heated and cured at a maximum temperature of 120 ° C., to produce a laminated film.

[Examples 4 to 6]
Laminated films of Examples 4 to 6 were produced in the same manner as in Example 1, except that Film 1 of Example 1 was changed to Films 2 to 4 as shown in Table 1.
[Evaluation]
The laminated films of the examples and the comparative examples produced above were evaluated according to the above-described measurement methods and evaluation methods. Table 1 shows the results.

Claims (10)

  A laminated film having a cured layer of an active energy ray-curable composition containing a compound having an alkyl group having 8 or more carbon atoms on at least one surface of an unstretched polyolefin film.   The laminated film according to claim 1, wherein the compound having an alkyl group having 8 or more carbon atoms is a compound (α) containing an ethylenically unsaturated group and an alkyl group having 8 or more carbon atoms in a molecule.   The laminated film according to claim 1, wherein the active energy ray-curable composition contains a compound (β) having an ethylenically unsaturated group in the molecule and not having an alkyl group having 8 or more carbon atoms.   The laminated film according to any one of claims 1 to 3, wherein the cured layer has a center line average roughness Ra of 10 nm or more.   The laminated film according to any one of claims 1 to 4, wherein the haze value is 1.5% or more. Surface free energy of the cured layer is 20~35mJ / ^{m 2,} laminated film according to claim 1.   A release film comprising the laminated film according to claim 1.   A release film for transfer, which is used for laminating a layer to be transferred on the cured layer of the laminated film according to claim 1.   An adhesive layer transfer film, wherein an adhesive layer is laminated on the cured layer of the laminated film according to claim 1.   The laminated film according to any one of claims 1 to 6, having a cured layer only on one surface of the unstretched polyolefin film, wherein an adhesive layer is laminated on a surface of the laminated film opposite to the cured layer. the film.