JP7260474B2 - release film - Google Patents

Description

The present invention relates to release films. Specifically, it relates to a release film comprising a release layer containing particles on a base film.

A release film comprising a particle-containing release layer on a base film is known to be used for imparting a matte tone to a transfer layer (Patent Documents 1 to 3). Such a transfer layer includes, for example, a hard coat layer, a sealing material layer for a semiconductor element, a protective layer for an electromagnetic wave shielding film, and the like.

On the other hand, it is known to use a non-silicone release film to avoid troubles in precision electronic equipment and the like. A release film using a long-chain alkyl group-containing polymer as a non-silicone release agent is known (Patent Document 4).

JP 2015-214032 A JP 2016-92272 A JP 2018-27642 A Japanese Patent Application Laid-Open No. 2003-300283

For example, the release film for the above-mentioned applications may have poor releasability from the transfer layer after hot pressing. In addition, the organic solvent contained in the coating composition for forming the transfer layer swells or dissolves the surface of the release layer, which may destabilize the releasability between the release layer and the transfer layer.

In particular, when the release layer contains particles and irregularities are formed on the surface of the release layer, the above problems tend to be exacerbated.

However, the release films described in Patent Documents 1 to 4 do not fully satisfy the peelability and solvent resistance after hot pressing.

Accordingly, an object of the present invention is to improve the releasability and solvent resistance after hot pressing of a release film having a release layer containing particles. Another object of the present invention is to reduce the glossiness of the transfer layer by using such a release film.

The above objects have been achieved by the following inventions.
[1] A release film having a release layer on at least one surface of a base film, wherein the release layer is a cured layer of composition (I) or composition (II).

Composition (I): A thermosetting composition containing a compound (a) containing an alkyl group having 8 or more carbon atoms, a cross-linking agent (b) and particles (c).

Composition (II): an active energy ray-curable composition containing a compound (α) containing an alkyl group having 8 or more carbon atoms and particles (c).
[2] The release film of [1], wherein the cross-linking agent (b) in the composition (I) is a melamine-based cross-linking agent.
[3] [1] or [2], wherein the compound (a) containing an alkyl group having 8 or more carbon atoms in the composition (I) is a polyvinyl resin containing a long-chain alkyl group containing an alkyl group having 8 or more carbon atoms; The release film described in .
[4] The compound (α) containing an alkyl group having 8 or more carbon atoms in the composition (II) contains a polymerizable long-chain alkyl group containing an ethylenically unsaturated group and an alkyl group having 8 or more carbon atoms in the molecule. The release film according to [1], which is a compound (α1).
[5] [1] or [4], wherein the composition (II) further contains a polymerizable compound (β) that contains an ethylenically unsaturated group in the molecule and does not contain an alkyl group having 8 or more carbon atoms. The release film described in .
[6] The release film according to any one of [1] to [5], wherein the particles (c) have an average particle size of 0.5 to 20 μm.
[7] The release film according to any one of [1] to [6], wherein the average particle size of the particles (c) is 0.9 times or more the thickness of the release layer.
[8] The release film according to any one of [1] to [7], wherein the particles (c) are particles containing melamine resin and/or benzoguanamine resin.
[9] The release film according to any one of [1] to [8], wherein the particles (c) are melamine/silica composite particles.
[10] The release film according to any one of [1] to [9], wherein the center line average roughness Ra of the release layer surface is 100 nm or more.
[11] The release film according to any one of [1] to [10], wherein the release layer has a surface free energy of 20 to 35 mJ/m ² .

According to the present invention, it is possible to provide a release film having a particle-containing release layer with improved peelability and solvent resistance after hot pressing. In addition, by using the release film of the present invention, glossiness of the transfer layer can be reduced (matte tone can be imparted to the transfer layer).

It is a schematic cross-sectional view showing an example of compression molding used for manufacturing a semiconductor package.

The release film of the present invention has a release layer containing particles on at least one surface of the base film. The release layer is a cured layer of composition (I) or composition (II).

Composition (I): A thermosetting composition containing a compound (a) containing an alkyl group having 8 or more carbon atoms, a cross-linking agent (b) and particles (c).

Composition (II): an active energy ray-curable composition containing a compound (α) containing an alkyl group having 8 or more carbon atoms and particles (c).

A release film having a release layer formed of a cured layer of the above composition on a substrate film has good releasability and solvent resistance after hot pressing. In addition, since the release layer contains particles, a fine uneven structure can be formed on the surface of the release layer, and a fine uneven structure can be imparted to the transfer layer. That is, the transfer layer can be imparted with a matte tone and low glossiness.

Composition (I) and composition (II) are described in detail below.
[Composition (I)]
Composition (I) is a thermosetting composition containing a compound (a) containing an alkyl group having 8 or more carbon atoms, a cross-linking agent (b) and particles (c).

The alkyl group in the compound (a) containing an alkyl group having 8 or more carbon atoms includes a linear or branched alkyl group. The number of carbon atoms in the alkyl group of the compound (a) is preferably 10 or more, more preferably 12 or more, and particularly preferably 14 or more, from the viewpoint of improving peelability and solvent resistance after hot pressing. The number of carbon atoms in the alkyl group is preferably 30 or less, more preferably 28 or less, and particularly preferably 25 or less. In addition, in this specification, arbitrary combinations can be adopted for the upper limit and the lower limit of the numerical range.

In the following description, an alkyl group having 8 or more carbon atoms may be referred to as a "long-chain alkyl group". A compound (a) containing an alkyl group having 8 or more carbon atoms is sometimes referred to as a "long-chain alkyl group-containing compound (a)".

As the long-chain alkyl group-containing compound (a), a compound having a long-chain alkyl group in its side chain is preferably used. Specifically, long-chain alkyl group-containing polyvinyl resins, long-chain alkyl group-containing alkyd resins, long-chain alkyl group-containing acrylic resins, long-chain alkyl group-containing polyester resins, long-chain alkyl group-containing ether compounds, long-chain alkyl group-containing amine compounds and the like.

Among the above compounds, a long-chain alkyl group-containing polyvinyl resin, a long-chain alkyl group-containing alkyd resin, or a long-chain alkyl group-containing acrylic resin is preferable from the viewpoint of improving peelability and solvent resistance after hot pressing. Alkyl group-containing polyvinyl resins are particularly preferred. That is, in the release film of the present invention, the compound (a) containing an alkyl group having 8 or more carbon atoms in the composition (I) is a long-chain alkyl group-containing polyvinyl resin containing an alkyl group having 8 or more carbon atoms. is particularly preferred.

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

Examples of long-chain alkyl group-containing isocyanate compounds include monoisocyanate compounds having an alkyl group with 8 or more carbon atoms. Specific examples include octyl isocyanate, nonyl isocyanate, decyl isocyanate, dodecyl isocyanate, tetradecyl isocyanate, hexadecyl isocyanate and octadecyl isocyanate.

Examples of long-chain alkyl group-containing alkyd resins include those obtained by modifying a condensate of a polybasic acid having a long-chain alkyl group and a polyhydric alcohol with a modifier such as fatty oil or fatty acid. 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. Basic acids, cyclopentadiene-maleic anhydride adducts, terpene-maleic anhydride adducts, rosin-maleic anhydride adducts, and other polybasic acids. 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. , dipentaerythritol, mannitol, sorbitol, and other tetravalent or higher alcohols. Modifiers include soybean oil, linseed oil, paulownia oil, castor oil, dehydrated castor oil, coconut oil, fatty acids thereof, stearic acid, oleic acid, linoleic acid, linoleic acid, eleostearic acid, ricinoleic acid, dehydrated Oils and fatty acids such as ricinoleic acid, natural resins such as rosin, kovar, amber and shellac, synthetic resins such as ester gums, phenol resins, urea resins and melamine resins. A cured resin of a stearic acid-modified alkyd resin and/or a stearic acid-modified acrylic resin and an amino resin is also preferable from the viewpoint of the balance between coatability and peelability.

Examples of acrylic resins containing long-chain alkyl groups include acrylic acid monomers or methacrylic acid monomers having long-chain alkyl groups, such as octyl acrylate, octyl methacrylate, lauryl acrylate, lauryl methacrylate, octadecyl acrylate, octadecyl methacrylate, and the like. homopolymer or copolymer of.

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

The long-chain alkyl group-containing compound (a) described above is commercially available and can be used. Commercially available products include "K-256", "N-137", "P-677", and "Q-472" of the Resem series manufactured by Chukyo Yushi Co., Ltd., and "Ashioresin (registered trademark)" manufactured by Asio Sangyo Co., Ltd. " series "RA-80", "RA-95H", "RA-585S", Lion Specialty Chemicals Co., Ltd. "Peeloil (registered trademark)" series "HT", "1050", "1010 ”, “1070”, “406”, “ZF-15” and “ZF-15H” manufactured by Nippon Vinyl Poval Co., Ltd., “Epomin (registered trademark)” “RP-20” manufactured by Nippon Shokubai Co., Ltd., etc. be done.

Examples of the cross-linking agent (b) contained in the composition (I) include epoxy-based cross-linking agents, isocyanate-based cross-linking agents, oxazoline-based cross-linking agents, carbodiimide-based cross-linking agents, and melamine-based cross-linking agents. Among these, a melamine-based cross-linking agent is particularly preferably used. That is, in the release film of the present invention, the cross-linking agent (b) in composition (I) is preferably a melamine-based cross-linking agent.

Examples of epoxy-based cross-linking agents include ethylene glycol diglycidyl ether, glycerol polyglycidyl ether, and polybutadiene diglycidyl ether.

Examples of isocyanate-based cross-linking agents include hexamethylene diisocyanate, isophorone diisocyanate tolylene diisocyanate, and methylene diphenyl diisocyanate.

Examples of oxazoline cross-linking agents include 2,2'-bis(2-oxazoline), 2,2'-ethylene-bis(4,4'-dimethyl-2-oxazoline), 2,2'-p-phenylene oxazoline group-containing compounds such as bis(2-oxazoline) and bis(2-oxazolinylcyclohexane)sulfide, and oxazoline group-containing polymers.

Carbodiimide-based cross-linking agents include p-phenylene-bis(2,6-xylylcarbodiimide), tetramethylene-bis(t-butylcarbodiimide), cyclohexane-1,4-bis(methylene-t-butylcarbodiimide) and the like. Compounds having a carbodiimide group and polycarbodiimide, which is a polymer having a carbodiimide group, can be mentioned.

A melamine compound used as a melamine-based cross-linking agent is a so-called melamine [1,3,5-triazine-2,4,6-triamine] in which an amino group is bonded to each of the three carbon atoms of a triazine ring. It is a general term for various modified compounds, including those in which multiple triazine rings are condensed. As the type of modification, a methylolated melamine compound in which at least one of the hydrogen atoms of the three amino groups is methylolated is preferable, and the methylol group of the methylolated melamine compound is partially or partially modified with a lower alcohol having 1 to 4 carbon atoms. Fully etherified alkyl-etherified melamine compounds are preferred.

Alcohols used for etherification include, for example, methyl alcohol, ethyl alcohol, propyl alcohol, and butyl alcohol.

A commercially available product can be used as the melamine-based cross-linking agent. Commercially available products include, for example, "Super Beckamin (registered trademark)" J-820-60, J-821-60, J-1090-65, J-110-60, J-110-60, manufactured by DIC Corporation. J-117-60, J-127-60, J-166-60B, J-105-60, G840, G821, "Uban (registered trademark)" 20SB manufactured by Mitsui Chemicals, Inc., 20SE60, 21R, 22R, 122, 125, 128, 220, 225, 228, 28-60, 2020, 60R, 62, 62E, 360, 165, 166-60, 169, 2061, "Sumimaru (registered trademark)" M-100, M-40S, M-55, M-66B manufactured by Sumitomo Chemical Co., Ltd., "Cymel (registered trademark)” 303, 325, 327, 350, 370, 235, 202, 238, 254, 272, 1130; )” MS17, MX15, MX430, MX600, Vansemin SM-975 and SM-960 manufactured by Harima Chemicals Co., Ltd., “Melan (registered trademark)” 265 and 2650L manufactured by Hitachi Chemical Co., Ltd. mentioned.

Composition (I) preferably contains an acid catalyst (d) to accelerate curing. Acid catalysts (d) include sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, p-toluenesulfonic acid and the like. Among these, p-toluenesulfonic acid is preferably used.

The content of the long-chain alkyl group-containing compound (a) in the composition (I) is 3% by mass or more with respect to 100% by mass of the total solid content of the composition, from the viewpoint of improving the peelability after hot pressing. is preferred, 5% by mass or more is more preferred, and 7% by mass or more is particularly preferred. On the other hand, if the content of the long-chain alkyl group-containing compound (a) is too high, the strength (hardness) of the release layer may decrease and the solvent resistance and heat resistance may decrease. The content of compound (a) is preferably 95% by mass or less, more preferably 90% by mass or less, and particularly preferably 85% by mass or less.

The content of the cross-linking agent (b) in the composition (I) is preferably 3% by mass or more with respect to 100% by mass of the total solid content of the composition, from the viewpoint of improving the solvent resistance of the release layer. 5% by mass or more is more preferable, and 10% by mass or more is particularly preferable. On the other hand, if the content of the cross-linking agent (b) is too high, the release force on the surface of the release layer may increase or become unstable. % by mass or less is preferable, and 95% by mass or less is more preferable.

From the viewpoint of further improving the solvent resistance of the release layer, the content of the cross-linking agent (b) is preferably at least 1.0 times the mass of the long-chain alkyl group-containing compound (a), and at least 2.0 times the mass. is more preferable, 2.5 times by mass or more is more preferable, 3.0 times by mass or more is particularly preferable, and 5.0 times by mass or more is most preferable. The upper limit is about 20.0 times by mass.

The content of the acid catalyst (d) in the composition (I) is from 0.1 to 0.1 with respect to 100% by mass of the total solid content of the composition, from the viewpoint of improving the peelability and solvent resistance after hot pressing. A range of 10% by weight is preferred, a range of 0.3 to 5% by weight is more preferred, and a range of 0.5 to 3% by weight is particularly preferred.

Particles (c) contained in composition (I) will be described later.

The release layer composed of the cured layer of the composition (I) is preferably formed by heating and curing the composition (I) applied on the substrate film. The conditions (heating temperature and time) for heat-curing the composition (I) are not particularly limited, but the heating temperature is preferably 70° C. or higher, more preferably 100° C. or higher, and particularly preferably 150° C. or higher. The upper limit is about 300°C. The heating time is preferably 3 to 300 seconds, more preferably 5 to 200 seconds.

Composition (I) can be applied, for example, by a wet coating method. Examples of wet coating methods include reverse coating, spray coating, bar coating, gravure coating, rod coating, die coating, spin coating, extrusion coating, and curtain coating.
[Composition (II)]
Composition (II) is an active energy ray-curable composition containing a compound (α) containing an alkyl group having 8 or more carbon atoms and particles (c). Hereinafter, the compound (α) containing an alkyl group having 8 or more carbon atoms is sometimes referred to as a "long-chain alkyl group-containing compound (α)".

The alkyl group in the long-chain alkyl group-containing compound (α) includes linear or branched alkyl groups. The number of carbon atoms in the alkyl group of the compound (α) is preferably 10 or more, more preferably 12 or more, and particularly preferably 14 or more, from the viewpoint of improving peelability and solvent resistance after hot pressing. The number of carbon atoms in the alkyl group is preferably 30 or less, more preferably 28 or less, and particularly preferably 25 or less.

Composition (II) contains a compound that is polymerized and cured by an active energy ray (hereinafter referred to as a polymerizable compound). Examples of such polymerizable compounds include compounds (monomers and oligomers) having at least one ethylenically unsaturated group in the molecule. Here, the ethylenically unsaturated group includes an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group, an allyl group, a vinyl group and the like.

The long-chain alkyl group-containing compound (α) may be a polymerizable compound or a non-polymerizable compound. That is, the long-chain alkyl group-containing compound (α) includes a polymerizable long-chain alkyl group-containing compound (α1) and a non-polymerizable long-chain alkyl group-containing compound (α2).

The polymerizable long-chain alkyl group-containing compound (α1) is a compound containing an ethylenically unsaturated group and an alkyl group having 8 or more carbon atoms in the molecule. In the release film of the present invention, the compound (α) containing an alkyl group having 8 or more carbon atoms in the composition (II) is polymerizable containing an ethylenically unsaturated group and an alkyl group having 8 or more carbon atoms in the molecule A long-chain alkyl group-containing compound (α1) is preferred.

Examples of the non-polymerizable long-chain alkyl group-containing compound (α2) include compounds similar to the long-chain alkyl group-containing compound (a) contained in the composition (I) described above.

In the release film of the present invention, it is preferable that the composition (II) further contains a polymerizable compound (β) that contains an ethylenically unsaturated group in the molecule and does not contain an alkyl group having 8 or more carbon atoms. . Hereinafter, a polymerizable compound containing an ethylenically unsaturated group in the molecule and not containing an alkyl group having 8 or more carbon atoms is sometimes referred to as a "polymerizable compound (β)".

In particular, when the composition (II) contains only the non-polymerizable long-chain alkyl group-containing compound (α2) as the long-chain alkyl group-containing compound (α), it is necessary to contain the polymerizable compound (β). The details of the polymerizable compound (β) will be described later.

In the composition (II), a polymerizable long-chain alkyl group-containing compound (α1) and a non-polymerizable long-chain alkyl group-containing compound (α2) can be used in combination, or a polymerizable long-chain alkyl group-containing compound (α1) and the polymerizable compound (β) can be used in combination, or the polymerizable long-chain alkyl group-containing compound (α1), the non-polymerizable long-chain alkyl group-containing compound (α2), and the polymerizable compound (β ) can be used in combination.

The composition (II) preferably contains a polymerizable long-chain alkyl group-containing compound (α1), and furthermore, the polymerizable long-chain alkyl group-containing compound (α1) and the polymerizable compound (β) are used in combination. is particularly preferred.

When the release layer is a cured layer of the active energy ray-curable composition, the peelability and solvent resistance after hot pressing are improved.

Specific examples of the polymerizable long-chain alkyl group-containing compound (α1) are shown below. In the following description, "... (meth)acrylate" is a generic term for "... acrylate" and "... methacrylate".

Examples of the polymerizable long-chain alkyl group-containing compound (α1) include octyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, and octadecyl (meth)acrylate. Acrylate, nonadecyl (meth)acrylate, eicosyl (meth)acrylate and the like.

In particular, the following polymerizable long-chain alkyl group-containing compound (α1) is preferably used. Such compounds include, for example, a (meth)acrylate compound having one or more (meth)acryloyl groups and one or more hydroxyl groups in the molecule, a polyisocyanate compound having two or more isocyanate groups in the molecule, and Compounds obtained by reacting with 8 to 30 higher alcohols can be mentioned.

Examples of the (meth)acrylate compounds 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-(meth)acryloyloxypropyl (meth)acrylate, 2-(meth)acryloyloxyethyl-2-hydroxyethyl phthalate, 2-(meth)acrylate Royloxyethyl-2-hydroxypropyl phthalate, 2-(meth)acryloyloxyethyl-acid phosphate, epoxy (meth)acrylate, pentaerythritol mono(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate ) acrylate, dipentaerythritol mono(meth)acrylate, dipentaerythritol di(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, in the molecule and (meth)acrylates having 2 to 30 alkyleneoxy groups (eg, ethyleneoxy group, propyleneoxy group, butyleneoxy group, etc.).

Among the above compounds, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4 -Hydroxybutyl (meth)acrylate, and (meth)acrylate having 2 to 30 alkyleneoxy groups in the molecule are preferably used.

Examples of polyisocyanate compounds 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, Diisocyanate compounds such as hydrogenated xylylene diisocyanate, biuret-type polyisocyanate compounds obtained by reacting these various diisocyanate compounds with water, or obtained by reacting various diisocyanate compounds with polyhydric alcohols such as trimethylolpropane. Adduct-type polyisocyanate compounds such as polyisocyanate compounds obtained from polyisocyanate compounds, or polymers obtained by converting various compounds into isocyanurates.

Among the above polyisocyanate compounds, compounds with a molecular weight of 50 to 500 are preferred, compounds with a molecular weight of 100 to 400 are more preferred, and compounds with a molecular weight of 130 to 300 are particularly preferred. For example, hexamethylene diisocyanate (molecular weight 168) and diphenylmethane diisocyanate (molecular weight 250) are exemplified as preferred compounds. In particular, diphenylmethane diisocyanate (molecular weight: 250) is preferred from the viewpoint of improving peelability and solvent resistance after hot pressing.

Examples of higher alcohols include linear unsaturated higher alcohols such as octyl alcohol, decyl alcohol, lauryl alcohol, myristyl alcohol, cetanol, cetostearyl alcohol, stearyl alcohol, and behenyl alcohol. Examples include oleyl alcohol, and branched higher alcohols include 2-hexyldecanol, 2-octyldodecanol, and 2-decyltetradodecanol.

A commercial item can be used as a higher alcohol. For example, linear saturated higher alcohols include "Conol (registered trademark)" 10WS, Conol 1098, Conol 1275, Conol 20F, Conol 20P, Conol 1495, Conol 1670, Conol 1695, Conol 30CK, Conol 30OC, Conol 30RC. , Conol 30F, Conol 30S, Conol 30SS, Conol 30T, Conol 2265, Conol 2280 (trade name of Shin Nippon Rika Co., Ltd.), "Kalcol (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 (Kao ( (trade name) manufactured by Co., Ltd.), and the linear unsaturated higher alcohols include "Ricacol (registered trademark)" 60B, Ricacol 70B, Ricacol 75BJ, Ricacol 85BJ, Ricacol 90B, Ricacol 90BR, Ricacol 90BHR, and Ricacol 110BJ. ANGECOL (registered trademark) 50A, ANGECOL 60AN, ANGECOL 70AN, ANGECOL 80AN, ANGECOL 85AN, ANGECOL 90AN, ANGECOL 90NR, ANGECOL 90NHR (product names of Shin Nippon Rika Co., Ltd.), branched Higher alcohols of the type include "Njecol (registered trademark)" 160BR, Njecol 200A, Njecol 240A (trade name of Shin Nippon Rika Co., Ltd.) and the like.

Composition (II) preferably further contains a polymerizable compound (β). The polymerizable compound (β) is a compound containing an ethylenically unsaturated group in its molecule and not containing an alkyl group having 8 or more carbon atoms.

Examples of the polymerizable compound (β) include 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 acrylate, polypropylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, glycerin propoxytri(meth)acrylate, pentaerythritol mono(meth)acrylate ) 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, tri Pentaerythritol octa(meth)acrylate, pentaerythritol tri(meth)acrylate hexamethylene diisocyanate urethane pre-oligomer, pentaerythritol tri(meth)acrylate-toluene diisocyanate urethane oligomer, pentaerythritol tri(meth)acrylate-isophorone diisocyanate urethane oligomer, etc. be done.

Among the above compounds, compounds having 2 to 10 ethylenically unsaturated groups in the molecule are preferred, and compounds having 3 to 8 ethylenically unsaturated groups in the molecule are particularly preferred.

Composition (II) preferably further contains a photopolymerization initiator. Specific examples of such photopolymerization initiators include 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, methyl benzoyl formate, p-isopropyl-α-hydroxyisobutylphenone, α-hydroxyisobutylphenone, 2, Using carbonyl compounds such as 2-dimethoxy-2-phenylacetophenone and 1-hydroxycyclohexylphenyl ketone, sulfur compounds such as tetramethylthiuram monosulfide, tetramethylthiuram disulfide, thioxanthone, 2-chlorothioxanthone and 2-methylthioxanthone can be done. These photopolymerization initiators may be used alone or in combination of two or more.

In addition, photopolymerization initiators are generally commercially available and can be used. For example, Ciba Specialty Chemicals Co., Ltd. "Irgacure (registered trademark)" 184, Irgacure 907, Irgacure 379, Irgacure 819, Irgacure 127, Irgacure 500, Irgacure 754, Irgacure 250, Irgacure 1800, Irgacure 1870, Irgacure OXE01 , "DAROCUR (registered trademark)" TPO, DAROCUR1173, etc., "Speedcure (registered trademark)" MBB, Speedcure PBZ, Speedcure ITX, Speedcure CTX, Speedcure EDB, "Esacure (registered trademark)" ONE, Esacure KIP150, manufactured by Nihon SibelHegner Co., Ltd. KTO46, etc., "KAYACURE (registered trademark)" DETX-S manufactured by Nippon Kayaku Co., Ltd., KAYACURE CTX, KAYACURE BMS, KAYACURE DMBI, and the like.

The content of the long-chain alkyl group-containing compound (α) in the composition (II) is 1% by mass or more with respect to 100% by mass of the total solid content of the composition, from the viewpoint of improving the peelability after hot pressing. is preferred, 5% by mass or more is more preferred, and 7% by mass or more is particularly preferred. On the other hand, if the content of the long-chain alkyl group-containing compound (α) is too high, the strength (hardness) of the release layer may decrease, and the solvent resistance and heat resistance may decrease. The content of (α) is preferably 70% by mass or less, more preferably 50% by mass or less, and particularly preferably 30% by mass or less.

From the viewpoint of improving the solvent resistance of the release layer, the content of the polymerizable compound (β) in the composition (II) is preferably 10% by mass or more with respect to 100% by mass of the total solid content of the composition. , more preferably 20% by mass or more, and particularly preferably 30% by mass or more. On the other hand, if the content of the polymerizable compound (β) is too large, the peel strength after hot pressing may increase, so the content of the polymerizable compound (β) is preferably 90% by mass or less, and 80% by mass. % or less is more preferable, and 70 mass % or less is particularly preferable.

The content of the photopolymerization initiator in the composition (II) is suitably in the range of 0.1 to 10% by mass relative to 100% by mass of the total solid content of the composition, and in the range of 0.5 to 8% by mass. is preferred.

Particles (c) contained in composition (II) will be described later.

The release layer composed of the cured layer of the composition (II) is formed by irradiating the composition (II) applied on the substrate film with an active energy ray and curing it. Examples of active energy rays include ultraviolet rays, visible rays, infrared rays, electron beams, α rays, β rays, and γ rays. Among these active energy rays, ultraviolet rays and electron beams are preferred, and ultraviolet rays are particularly preferred.

The light source for irradiating ultraviolet rays is not particularly limited, but for example, ultraviolet fluorescent lamps, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, carbon arc lamps, metal halide lamps, xenon lamps, etc. can be used. . ArF excimer laser, KrF excimer laser, excimer lamp, synchrotron radiation, or the like can also be used. Among these, ultra-high pressure mercury lamps, high pressure mercury lamps, low pressure mercury lamps, carbon arc lamps, xenon lamps and metal halide lamps can be preferably used. Moreover, when irradiating with ultraviolet rays, it is preferable to irradiate in an atmosphere with a low oxygen concentration, for example, in an atmosphere with an oxygen concentration of 500 ppm or less, since curing can be efficiently performed.

The irradiation light amount of ultraviolet rays is preferably 50 mJ/cm ² or more, more preferably 100 mJ/cm ² or more, and particularly preferably 150 mJ/cm ² or more. Also, the amount of ultraviolet irradiation light is preferably 2000 mJ/cm ² or less, more preferably 1000 mJ/cm ² or less. Composition (II) can be applied by a wet coating method. Examples of wet coating methods include reverse coating, spray coating, bar coating, gravure coating, rod coating, die coating, spin coating, extrusion coating, and curtain coating.

[Common components of composition (I) and composition (II)]
Hereinafter, composition (I) and composition (II) may be collectively referred to as "composition".

<Particles (c)>
The composition contains particles (c). By including the particles (c) in the composition, a fine uneven structure can be formed on the surface of the release layer. The center line average roughness Ra of the release layer surface is preferably 100 nm or more, more preferably 200 nm or more, still more preferably 300 nm or more, and particularly preferably 400 nm or more. The upper limit is about 3000 nm.

From the above viewpoint, in the release film of the present invention, the particles (c) preferably have an average particle size of 0.5 to 20 μm. The average particle size of the particles (c) is preferably 0.5 μm or more, more preferably 1.0 μm or more, and particularly preferably 1.5 μm or more. On the other hand, if the average particle size of the particles (c) is too large, the dispersibility in the composition may deteriorate, the coating properties of the composition may deteriorate, or the particles may drop off from the release layer. , the average particle size of the particles (c) is preferably 20 μm or less, more preferably 10 μm or less, and particularly preferably 5 μm or less.

From the viewpoint of adjusting the center line average roughness Ra of the release layer surface to 100 nm or more, the average particle diameter of the particles (c) is preferably 0.9 times or more the thickness of the release layer. It is more preferably 1.5 times or more, and particularly preferably 2.0 times or more. On the other hand, if the ratio is too high, the particles may fall off from the release layer, so the ratio is preferably 10.0 times or less, preferably 7.0 times or less, and 5.0. It is particularly preferable that it is not more than double.

The content of the particles (c) in the composition is suitably 1 to 80% by mass, preferably 1 to 50% by mass, more preferably 3 to 40% by mass, relative to 100% by mass of the total solid content of the composition. Preferably, 5 to 35% by mass is more preferable, and 8 to 32% by mass is particularly preferable.

As the particles, organic particles, inorganic particles, and organic/inorganic composite particles can be used. Organic particles include acrylic resin particles, polystyrene resin particles, melamine resin particles, benzoguanamine resin particles, benzoguanamine/melamine resin particles, polyester resin particles, polyurethane resin particles, epoxy resin particles, polyolefin resin particles, polycarbonate resin particles, and polyamide resin particles. , fluororesin particles, and the like. Examples of inorganic particles include particles made of silica, titanium oxide, aluminum oxide, zirconium oxide, calcium carbonate, zeolite, and the like. The organic/inorganic composite particles include acrylic/silica composite particles, melamine/silica composite particles, benzoguanamine/silica composite particles, benzoguanamine/melamine/silica composite particles, polystyrene/silica composite particles, and the like. These particles may be used alone, or two or more of them may be used in combination. From the viewpoint of dispersibility and dispersion stability in the composition of the present invention, that is, a composition containing a long-chain alkyl group-containing compound. , organic particles or organic/inorganic composite particles are preferred, and particles containing melamine resin and/or benzoguanamine resin in the particles are more preferred.

That is, from the viewpoint of dispersibility and dispersion stability in the composition, melamine resin particles, benzoguanamine resin particles, benzoguanamine/melamine resin particles, melamine/silica composite particles, benzoguanamine/silica composite particles, and benzoguanamine/melamine/silica composite particles are used. preferable. From the viewpoint of dispersibility and dispersion stability, it is preferable that the above organic-inorganic composite particles have an organic resin arranged at least on the surface of the particles.

Among inorganic particles, hydrophobic silica particles are preferably used because they have relatively good dispersibility and dispersion stability in the composition. Hydrophobic silica particles can be obtained, for example, by treating the surface of silica particles with a silane compound.

Examples of silane compounds include trimethylchlorosilane, dimethylvinylchlorosilane, dimethyldichlorosilane, hexamethyldisilazane, 1,3-divinyl-1,1,3,3-tetramethyldisilazane, hexamethylcyclotrisilazane, trimethylhydroxy Silane, dimethylhydroxysilane, acryloxyethyltrimethoxysilane, acryloxypropyltrimethoxysilane, acryloxybutyltrimethoxysilane, acryloxypentyltrimethoxysilane, acryloxyhexyltrimethoxysilane, acryloxyheptyltrimethoxysilane, methacryloxy Ethyltrimethoxysilane, methacryloxypropyltrimethoxysilane, methacryloxybutyltrimethoxysilane, methacryloxyhexyltrimethoxysilane, methacryloxyheptyltrimethoxysilane, methacryloxypropylmethyldimethoxysilane, methacryloxypropylmethyldimethoxysilane, and the like. be done.

If the dispersibility and dispersion stability of the particles in the composition are poor, the coating properties of the composition may deteriorate, and a uniform release layer may not be obtained.

Particles having relatively high hardness are preferable as the particles contained in the composition. In the heat pressing step, the particles contained in the release layer preferably have a relatively high hardness in order to efficiently transfer and form the fine uneven structure on the surface of the release layer formed by the particles onto the transfer layer. Here, the hardness of particles can be represented by 10% compressive strength (compressive strength at 10% displacement). The 10% compression strength can be measured using a microcompression tester (for example, "MCTM2000" manufactured by Shimadzu Corporation).

From the above viewpoint, the 10% compression strength of the particles is preferably 40 MPa or more, more preferably 50 MPa or more, and particularly preferably 55 MPa or more. The upper limit is about 100 MPa. Particles having a relatively high 10% compression strength include, for example, the inorganic particles and organic/inorganic composite particles described above. Among organic particles, crosslinked acrylic resin particles, crosslinked polystyrene resin particles, melamine resin particles, and benzoguanamine Examples include resin particles, benzoguanamine/melamine resin particles, and the like.

From a comprehensive viewpoint of dispersibility/dispersion stability and 10% compressive strength, the particles (c) are preferably particles containing melamine resin and/or benzoguanamine resin. Preferred such particles are melamine resin particles, benzoguanamine resin particles, benzoguanamine/melamine resin particles, melamine/silica composite particles, benzoguanamine/silica composite particles, and benzoguanamine/melamine/silica composite particles. Among these, it is particularly preferable that the particles (c) are melamine/silica composite particles.

<Other common ingredients>
The composition may contain binder resins, antistatic agents, colorants, and the like. Examples of binder resins include polyurethane resins, acrylic resins, and polyester resins. Here, the binder resin is a compound containing no long-chain alkyl group.

The composition preferably does not contain silicone compounds. A release layer made of a composition containing a silicone-based compound may cause problems in precision electronic devices. Therefore, when the composition contains a silicone-based compound, it is preferably 5% by mass or less, more preferably 3% by mass or less, further preferably 1% by mass or less, with respect to 100% by mass of the total solid content of the composition. It is particularly preferred not to contain.

Here, the silicone-based compound refers to a silicone-based compound generally known as a silicone-based release agent. Silicone is a polymer consisting of a main chain made up of alternating silicon and oxygen bonds with organic groups (eg, alkyl groups, phenyl groups, etc.). For example, silicone compounds having polydimethylsiloxane as a basic skeleton are well known.

In addition, the composition can contain a fluorine-based release agent, but from the viewpoint of suppressing costs, the content of the fluorine-based release agent is 10% by mass relative to the total solid content of the composition of 100% by mass. The following is preferable, 5% by mass or less is more preferable, and 1% by mass or less is particularly preferable. Here, the fluorine-based release agent means a compound containing a fluorine atom.
[Release layer]
The thickness of the release layer is preferably 0.05 µm or more, more preferably 0.1 µm or more, and particularly preferably 0.2 µm or more, from the viewpoint of retaining particles having a relatively large average particle size. In addition, from the viewpoint of forming a fine concave-convex structure with particles in the release layer, the thickness is preferably 3.0 μm or less, more preferably 2.0 μm or less, and particularly preferably 1.5 μm or less.

From the viewpoint of improving the releasability after hot pressing and the viewpoint of improving the coatability of the transfer layer, the release layer preferably has a surface free energy of 20 to 35 mJ/m ² , more preferably 21 to 32 mJ/m ² . is more preferable, and 22 to 30 mJ/m ² is particularly preferable.

By forming the release layer with the composition (I) or composition (II) described above, the surface free energy of the release layer can be within the above range.

Here, the surface rough 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 surface roughness of the release layer is appropriately adjusted according to the application. Roughness Ra is preferably 100 nm or more, more preferably 200 nm or more, still more preferably 300 nm or more, and particularly preferably 400 nm or more. The upper limit is about 3000 nm. Here, the center line average roughness Ra is the surface roughness defined by JIS B0601 (1982).

Moreover, the surface roughness of the release layer may be adjusted by using a base film having a relatively large surface roughness. That is, it may be adjusted by providing a release layer containing particles on a substrate film having a relatively large center line average roughness Ra. The base film used here preferably has a center line average roughness Ra of 50 nm or more, more preferably 100 nm or more, and particularly preferably 200 nm or more. The upper limit is about 2000 nm.

[Base film]
Various resin films can be used as the base film used for the release film of the present invention. Examples of such resin films include polyester films such as polyethylene terephthalate film, polybutylene terephthalate film and polyethylene naphthalate film; polyolefin films such as polypropylene film and polyethylene film; cellulose films such as diacetyl cellulose film and triacetyl cellulose film; film, polyetheretherketone film, polyethersulfone film, polyphenylene sulfide film, polyetherimide film, polyimide film, polyamide film, acrylic film, cyclic olefin film, polycarbonate film and the like.

Among these resin films, a polyimide film, a polyester film, and a cyclic olefin film, which have good heat resistance, are preferable. A polyester film is preferable from the viewpoint of cost reduction. In addition, a biaxially oriented polyester film is preferable from the viewpoint of suppressing permeation of the release film by the gas generated from the sealing material during hot pressing in compression molding and suppressing contamination of the mold due to gas permeation. A biaxially oriented polyethylene terephthalate film is particularly preferred.

For example, a fluororesin film, which is generally used for compression molding for encapsulating a semiconductor element with an encapsulating material, has the problem that gas generated from the encapsulating material easily permeates it. By using an oriented polyester film, preferably a biaxially oriented polyethylene terephthalate film, the above problems are suppressed.

Further, in compression molding, it is preferable that the release film can easily follow the concave portion of the mold, and from this point of view, it is preferable that the base film has a relatively high elongation. Specifically, the stress at 100% elongation in the longitudinal direction (MD direction) and width direction (TD direction) of the base film at 150° C. is preferably 60 MPa or less, more preferably 50 MPa or less, It is more preferably 40 Ma or less, and particularly preferably 30 MPa or less. If the stress at 100% elongation is too small, it may break during elongation.

A biaxially oriented polyester film is preferable as the base film having high elongation. Biaxially oriented polyester film with high elongation (biaxially oriented polyester film for molding) is, for example, JP-A-2016-190438, JP-A-2016-159537, JP-A-2015-10121, JP-A-2012-126821. , 2011-073151, 2011-057850, 2010-189593, WO2013/099608, 2012/005097, and the like.

For biaxially oriented polyester films with high elongation, for example, "Soft Shine (registered trademark)" manufactured by Toyobo Co., Ltd. and "Teflex (registered trademark)" manufactured by Teijin DuPont Films Co., Ltd. can be used. can be done.

Preferably, the biaxially oriented polyester film has a three-layer laminate construction. A three-layer laminate structure includes A layer/B layer/A layer or A layer/B layer/C layer. Here, the A layer, the B layer, and the C layer mean different compositions. Among the three-layered structure described above, the three-layered structure of A layer/B layer/A layer is preferable from the viewpoint of simplification of production equipment and improvement of productivity.

The center line average roughness Ra of the base film (polyester film) can be appropriately adjusted depending on the use of the release film. The center line average roughness Ra of the base film (polyester film) can be controlled, for example, by adjusting the average particle diameter and content of particles contained in the A layer or the C layer in the three-layer structure. .

The thickness of the base film is appropriately set according to the use of the release film. Specifically, the thickness of the substrate film is preferably 10 to 150 μm, more preferably 15 to 100 μm, and particularly preferably 20 to 80 μm.

The base film can be provided with a primer layer on one or both sides thereof for suppressing precipitation of oligomer components generated from the base film. Examples of the primer layer include organosilicon compounds including organoaluminum compounds, polyvinyl alcohol, and the like.

Organosilicon compounds containing organoaluminum compounds include γ-methacryloxy group-containing organoalkoxysilanes, epoxy group-containing organoalkoxysilanes, vinyl group-containing organoalkoxysilanes, vinyl group-containing acetoxysilanes and mixtures thereof.

As the primer layer, a cured resin layer having a pencil hardness (pencil hardness defined by JIS K5600-5-4 (1999)) of F to 2H can be used. As this cured resin layer, conventionally known hard coat layer components can be appropriately adjusted and used.

The thickness of the primer layer is preferably 0.05 to 2.0 μm, more preferably 0.1 to 1.0 μm, particularly preferably 0.2 to 0.5 μm.

[Release film]
In the release film of the present invention, a release layer can be provided on one side or both sides of the base film. When the release layer is provided only on one side of the substrate film, it is necessary to provide the release layer composed of the composition (I) or (II) described above. When the release layer is provided on both sides of the base film, it is necessary to provide a release layer made of the composition (I) or (II) on one side, but the release layer on the other side is The mold layer may be a release layer composed of the composition (I) or (II) described above, or may be a different release layer.

In addition, as described above, the release film can be provided with a primer layer on one side or both sides of the base film for suppressing precipitation of oligomers. When the primer layer is provided on the release layer side, it is provided between the base film and the release layer.

[Application example of release film]
The release film of the present invention is suitable as a process film for forming a fine uneven structure on a transfer layer disposed on the release layer by coating or the like and imparting a matte tone or low glossiness to the surface of the transfer layer. Such a transfer layer is not particularly limited, but for example, a hard coat layer, a semiconductor element sealing material layer, a protective layer of an electromagnetic wave shielding film, a ferrite layer, a photosensitive resin layer, an adhesive layer, a synthetic leather, a decorative sheet, etc. is mentioned.

The release film of the present invention can be used, for example, as a process film when manufacturing an electromagnetic wave shielding film. In such a step, for example, a protective layer and an electromagnetic wave shielding layer (eg, metal layer/conductive adhesive layer) are laminated in this order on the release layer of the release film of the present invention to obtain an electromagnetic wave shielding film. The protective layer is formed by thermally curing or ultraviolet curing acrylic resin, phenolic resin, melamine resin, or epoxy resin, for example. For example, the electromagnetic wave shielding film is attached to a printed wiring board and hot-pressed to transfer the protective layer and the electromagnetic wave shielding layer of the electromagnetic wave shielding film.

Moreover, the release film of the present invention is suitable as a release film (release film) for a compression molding method for encapsulating a semiconductor element or a light-emitting element with a sealing material, for example.

A method of manufacturing a semiconductor package by compression molding will be described below with reference to FIG. FIG. 1 is a schematic cross-sectional view showing an example of compression molding used for manufacturing a semiconductor package.

An apparatus to which the compression molding method is applied comprises a lower mold 10 and an upper mold 20 . The lower mold 10 is a portion for mounting a substrate 2 (eg, silicon wafer) on which a semiconductor element 1 (eg, chip) is mounted, and has a flat surface in the illustrated example. The upper mold 20 is a mold that faces the semiconductor element 1 and the encapsulant 3, and is provided with a recess having a trapezoidal cross section in the illustrated example. The lower mold 10 and the upper mold 20 incorporate heaters (not shown) for heating and curing the sealing material 3 .

A release film 4 extending along the inner surface of the recess is attached to the lower surface of the upper mold 20 . The upper mold 20 is provided with a suction mechanism (not shown), and the release film 4 is attracted to and held by the concave portion of the upper mold 20 . The release film 4 is a member interposed between the upper mold 20 and the sealing material 3 so that the sealing material 3 does not come into direct contact with the upper mold 20 . The release film 4 is arranged such that its release layer (not shown) faces the sealing material 3 .

The upper mold 20 is lowered as indicated by an arrow to join with the lower mold 10, and the sealing material 3 is compressed and heated (hot pressed). As a result, the encapsulant 3 hardens into a shape along the recess of the upper mold 20 and seals the semiconductor element 1 . After curing the sealing material 3 , the upper mold 20 is separated from the lower mold 10 , and at the same time or after that, the release film 4 is peeled off from the sealing material 3 . As described above, the semiconductor element 1 mounted on the substrate 2 is sealed with the sealing material 3 .

The above manufacturing method is an example of the compression molding method, and the present invention is not limited thereto. As another compression molding method, for example, a release film and a sealing material are placed in this order on a lower mold having a recess, and a substrate on which a semiconductor element (chip) is mounted is sucked and held. There is a method in which the mold is lowered, the lower mold and the upper mold are combined, the substrate on which the semiconductor element is mounted and the sealing material are hot pressed, and the semiconductor element is sealed with the sealing material.

It is preferable that the release film used in the compression molding method has good conformability to the mold. From this point of view, the stress at 100% elongation in the longitudinal direction (MD direction) and the width direction (TD direction) of the release film at 150 ° C. is preferably 60 MPa or less, more preferably 50 MPa or less, and 40 Ma. It is more preferably 30 MPa or less, particularly preferably 30 MPa or less. If the stress at 100% elongation is too small, it may break during elongation. As described above, such a release film preferably has a stress at 100% elongation in the longitudinal direction (MD direction) and width direction (TD direction) at 150° C. of 60 MPa or less. , more preferably 50 MPa or less, more preferably 40 MPa or less, and particularly preferably 30 MPa or less.

As described above, one of the preferred application examples of the release film of the present invention is the compression molding method for semiconductor packages. This is a compression molding method in which a release layer of a mold film and a sealing material are arranged to face each other, and the sealing material and a semiconductor element are arranged to face each other and are hot-pressed.

[Sealant]
The encapsulating material used in the compression molding method is not particularly limited, and known encapsulating materials for semiconductor elements, light-emitting elements, and the like can be used. The sealing material preferably contains a thermosetting resin. Thermosetting resins include, for example, epoxy thermosetting resins, phenolic thermosetting resins, melamine thermosetting resins, alkyd thermosetting resins, acrylic thermosetting resins, and polyurethane thermosetting resins. , polyimide-based thermosetting resins, polyamide-imide-based thermosetting resins, and the like. Among these, epoxy thermosetting resins are preferred.

The sealing material preferably contains an inorganic filler. Examples of inorganic fillers include silica, aluminum hydroxide, calcium carbonate, aluminum oxide, boron nitride, silicon nitride, titanium oxide and barium titanate.

The inorganic filler is, for example, granular and has a function of adjusting the viscosity, hardness, etc. of the sealing material. The content of the inorganic filler in the sealing material is preferably 50% by mass to 90% by mass.

Encapsulants are commercially available and can be used. For example, "CEL-9740" and "CEL-C-2902" manufactured by Hitachi Chemical Co., Ltd., "Sumicon (registered trademark)" manufactured by Sumitomo Bakelite Co., Ltd. "EME-A730" and "EME-G770", "R4212" manufactured by Nagase ChemteX Co., Ltd. and the like can be mentioned.

EXAMPLES The present invention will be described in detail below with reference to Examples, but the present invention is not limited to these Examples.

Measurement methods and evaluation methods are shown below.
(1) Measurement of the average particle size of the particles contained in the release layer Observe the cross section of the release film with an electron microscope, and measure the maximum length of each of 30 randomly selected particles from the cross-sectional photograph. The average particle diameter of the particles was determined by arithmetically averaging them.
(2) Measurement of 10% compressive strength of particles Using a microcompression tester "MCTM2000" manufactured by Shimadzu Corporation, one particle is compressed at a constant load rate of 0.98 mN / sec, It was calculated by inserting the load when the particles were deformed by 10% and the particle diameter before compression into Equation 1 below. Five randomly collected samples were measured, and the average value was defined as "10% compressive strength". Measurement conditions are shown below.

10% compressive strength (MPa) = 2.8P/πD ² Equation 1
(In Formula 1, P represents the load (N) and D represents the particle diameter (mm).)
<Measurement conditions>
・Measurement environment; temperature 23±1°C, relative humidity 55±5%
・Upper pressurizing indenter: flat indenter with a diameter of 50 μm (material: diamond)
・Lower pressure plate; SKS flat plate (3) Measurement of center line average roughness Ra of base film and release layer Laboratory) was used for measurement.

<Measurement conditions>
・Feeding speed: 0.5mm/Sec
・Evaluation length: 8 mm
・Cutoff value λc;
When Ra is 20 nm or less, λc = 0.08 mm
When Ra is greater than 20 nm and less than or equal to 100 nm, λc = 0.25 mm
When Ra is greater than 100 nm and less than or equal to 2000 nm, λc = 0.8 mm
When measuring under the above measurement conditions, the measurement was first performed with a cutoff value λc=0.8 mm, and as a result, when Ra was greater than 100 nm, that Ra was adopted. On the other hand, when Ra was 100 nm or less as a result of the above measurement, measurement was performed again with λc=0.25 mm, and as a result, when Ra was greater than 20 nm, that Ra was adopted. On the other hand, when Ra was 20 nm or less as a result of the above remeasurement, measurement was performed with λc=0.08 mm, and that Ra was adopted.
(4) Measurement of the thickness of the base film and the release layer A sample for cross-sectional observation of the release film is subjected to the FIB method using a microsampling system (Hitachi FB-2000A) (specifically, "polymer surface processing (based on the method described in Akira Iwamori, p. 118-119). A transmission electron microscope (H-9000UHRII manufactured by Hitachi) was used to observe the cross section of the sample for cross section observation at an acceleration voltage of 300 kV, and the thicknesses of the base film and release layer were measured. For the thickness of the release layer, the thickness was measured at a location where no protrusions due to particles were present on the surface of the release layer.
(5) Measurement of surface free energy of release layer Water, diiodomethane, and 1-bromonaphthalene were used as three types of liquids with known values of surface free energy and its components (dispersion force, polar force, and hydrogen bonding force). The contact angle of each liquid on the release layer was measured using a contact angle meter DropMaster DM501 (manufactured by Kyowa Interface Science Co., Ltd.) at 23° C. and 65% RH. Five measurements were taken on one measurement surface, and the average value was taken as the contact angle (θ). From the value of this contact angle (θ) and the known value of each liquid (Method IV by Panzer (described in Journal of the Adhesion Association of Japan, Vol. 15, No. 3, p. 96), it is introduced from the Kitazaki-Hata equation. The value of each component was calculated using the following formula.

(γSd·γLd) ^1/2 +(γSp·γLp) ^1/2 +(γSh·γLh) ^1/2 =γL(1+cos θ)/2
Here, γLd, γLp, and γLh represent the components of the dispersion force, polar force, and hydrogen bonding force of the liquid to be measured, respectively, θ represents the contact angle of the liquid to be measured on the measurement surface, and γSd, γSp, γSh represents the value of each component of the dispersion force, polar force, and hydrogen bonding force on the surface of the laminated film, and γL represents the surface energy of each liquid (all units are mJ/m ² ). By solving the simultaneous equations obtained by substituting the known values and θ into the above equation, the values of the three components of the measurement surface (releasing layer surface) were obtained.

As shown in the following formula, the sum of the value of the dispersion force component, the value of the polar force component, and the value of the hydrogen bonding force component was taken as the value of the surface free energy (E; mJ/m ² ).

E = γSd + γSp + γSh
(6) Measurement of stress at 100% elongation at 150 ° C. of the base film <Preparation of test sample>
A test sample a cut out from the base film in the longitudinal direction and the width direction into rectangles with a long side of 150 mm and a short side of 10 mm, and cut out so that the longitudinal direction (MD direction) of the base film is the long side, and the base A test sample b was prepared by cutting out such that the width direction (TD direction) of the film was the long side.
<Measurement of stress>
A tensile tester (“Tensilon UCT-100” manufactured by Orientec Co., Ltd.) is installed in an oven with a window so that the tensile state of the test sample can be observed while irradiating a white LED light from the window of the oven. Furthermore, the tensile tester can be operated from outside the oven.

When the temperature of the oven reaches 150 ° C., open the oven and quickly set the test sample in the tensile tester, raise the temperature of the oven again and confirm that it has reached 150 ° C. Measurements were taken at an initial chuck-to-chuck distance of 50 mm. Read the load applied to the test sample when the test sample is stretched by 100% (when the distance between chucks is 100 mm), and divide the value by the cross-sectional area of the sample before the test (thickness of the base film x 10 mm). % elongation stress. The measurement was performed five times each for test sample a and test sample b, and the respective values were averaged to calculate the stress in the longitudinal direction (MD direction) and the stress in the width direction (TD direction).
(7) Evaluation of peelability after hot pressing A silicon wafer is placed on the lower mold of a compression molding device (“WCM-300MS” manufactured by Apic Yamada Co., Ltd.), and an epoxy-based sealing material ( "R4212-2" (liquid resin) manufactured by Nagase ChemteX Corporation was dispensed to a thickness of about 250 µm. A release film is attached to the upper mold so that the release layer faces the sealing material, and the silicon wafer and the sealing material are hot-pressed under the following molding conditions to adhesively coat the silicon wafer with the sealing material. bottom.
<Molding conditions>
・Temperature: 120°C
- Pressure; 3.5 MPa
Time: 10 minutes <Evaluation of releasability between sealing material and release film after molding>
The peelability between the sealing material and the release film after molding was evaluated according to the following criteria.
A; When it can be easily peeled B; When it is not easily peeled, but when it can be peeled off by applying a certain amount of force C; In the compression molding of 7), the state of suction and adsorption of the release film to the upper mold was visually observed and evaluated according to the following criteria.
A: When the release film can be adsorbed without wrinkles B: When there is air leakage from the end, or wrinkles occur on the release film during adsorption (9) Measurement of glossiness of transfer layer (sealant layer) In the compression molding of (7) above, the 60 degree glossiness of the surface of the sealing material layer transferred onto the silicon wafer was measured by the following method.

<Measurement of 60 degree glossiness>
According to the method specified in JIS-Z-8741 (1997), measurement was performed using a digital variable angle gloss meter UGV-5D manufactured by Suga Test Instruments. The measurement was performed 5 times, the average value excluding the maximum value and the minimum value was adopted, and evaluation was made according to the following criteria.
A; 60 degree glossiness is less than 20;
B; 60 degree glossiness is 20 or more and less than 30;
C; 60 degree glossiness is 30 or more.
(10) Evaluation of Solvent Resistance of Release Layer Methyl ethyl ketone (MEK), toluene, and ethyl acetate were used as organic solvents, and the solvent resistance to each organic solvent was evaluated in the following manner.

The surface of the release layer of the release film was rubbed back and forth five times with a cotton swab soaked in the above organic solvent, and the state of the release layer was visually observed and evaluated according to the following criteria.
A: When the release layer does not change with any of the above three solvents B; When there is a solvent that whitens the release layer among the above three solvents C: A release layer among the above three solvents (11) Evaluation of uniformity of release layer surface The uniformity of the release layer surface was visually observed and evaluated according to the following criteria.
A: Uniform without coating streaks and coating unevenness.
B: Slight coating streaks or coating unevenness, but acceptable level.
C: Coating streaks or coating unevenness are strongly generated and are at an unacceptable level.
[Preparation of base film]
As a base film, the following biaxially oriented polyethylene terephthalate film (PET film) was prepared.
<PET film 1>
A polyester film having a three-layer laminate structure of A layer/B layer/A layer was produced in the following manner. The raw materials for each layer are shown below.
Layer A: contains 94% by mass of polyester a below, 5% by mass of polyester b below, and 1% by mass of particle master c1 below.
• Layer B: contains 50% by mass of the following polyester a and 50% by mass of the following polyester b.
(Preparation of polyester a)
A polyethylene terephthalate resin (intrinsic viscosity of 0.65) containing 100 mol % of terephthalate as a dicarboxylic acid component and 100 mol % of ethylene glycol as a glycol component.
(Preparation of polyester b)
Copolyester (GN001 manufactured by Eastman Chemical Co.) in which 1,4-cyclohexanedimethanol is copolymerized with 33 mol % of the glycol component was used as cyclohexanedimethanol-copolymerized polyethylene terephthalate (intrinsic viscosity 0.75). .
(Preparation of particle master c1)
A polyethylene terephthalate particle master (intrinsic viscosity of 0.65) containing aggregated silica particles having a number average particle size of 2.2 µm in polyester a at a particle concentration of 2% by mass.
(Production of PET film 1)
The raw material for the A layer and the raw material for the B layer were each supplied to separate co-vented twin-screw extruders with an oxygen concentration of 0.2% by volume, and the cylinder temperature of the A layer extruder was 270 ° C., and the B layer was extruded. The material was melted at a machine cylinder temperature of 277°C, and after the A layer and B layer were merged, the short tube temperature was 277°C, the nozzle temperature was 280°C, and the mixture was discharged in a sheet form onto a cooling drum temperature-controlled at 25°C from a T-die. . At that time, static electricity was applied using a wire-shaped electrode having a diameter of 0.1 mm, and the film was brought into close contact with a cooling drum to obtain a three-layer laminated unstretched film consisting of A layer/B layer/A layer. Next, before stretching in the longitudinal direction, the film temperature was raised with a heating roll, the preheating temperature was 80 ° C., the stretching temperature was 85 ° C., and the metal was stretched 3.6 times in the longitudinal direction, and the temperature was immediately controlled at 40 ° C. Cooled with rolls.

Next, it is stretched 3.8 times in the width direction at a preheating temperature of 85° C. and a stretching temperature of 95° C. with a tenter type transverse stretching machine, and heat-treated at a temperature of 234° C. for 5 seconds in the tenter as it is, and then 5 times in the width direction. A heat treatment was performed at 150° C. for 3 seconds while applying a 10% relaxation to obtain a biaxially oriented polyester film. The total thickness of this polyester film was 50 μm, the thickness of each of the A layers was 5 μm, and the thickness of the B layer was 40 μm. The center line average roughness Ra of this polyester film was 23 nm on both sides.
<PET film 2>
A polyethylene terephthalate film (“Lumirror (registered trademark)” S10 manufactured by Toray Industries, Inc.) having a thickness of 50 μm was prepared. The center line average roughness Ra was 25 nm for both surfaces.
<PET film 3>
A polyester film having a three-layer laminate structure of A layer/B layer/A layer was produced in the following manner. The raw materials for each layer are shown below.
Layer A: contains 70% by mass of polyester a, 5% by mass of polyester b and 25% by mass of particle master c2 described below.
• Layer B: contains 50% by mass of polyester a and 50% by mass of polyester b.
(Preparation of particle master c2)
A polyethylene terephthalate particle master (intrinsic viscosity of 0.65) containing aggregated silica particles having a number average particle size of 3.0 µm in polyester a at a particle concentration of 15% by mass.
(Production of PET film 3)
The raw material for the A layer and the raw material for the B layer were each supplied to separate single screw extruders with an oxygen concentration of 0.2% by volume, and the A layer extruder cylinder temperature was 270 ° C. and the B layer extruder cylinder temperature was 270. After the A layer and the B layer merge, the short tube temperature is set to 275°C, the nozzle temperature is set to 280°C, the resin temperature is 280°C, and the temperature is controlled to 25°C by the T die. was discharged to At that time, static electricity was applied using a wire-shaped electrode with a diameter of 0.1 mm, and the sheet was brought into close contact with a cooling drum to obtain an unstretched sheet. Next, before stretching in the longitudinal direction, the temperature of the film was raised by heating rolls, and the film was stretched 3.1 times in the longitudinal direction at a stretching temperature of 85°C, and immediately cooled to 40°C with metal rolls. After that, the film is stretched 3.5 times in the width direction with a tenter-type transverse stretching machine at a temperature of 110°C in the first half of stretching, a temperature of 125°C in the middle of stretching, and a temperature of 140°C in the second half of stretching. After heat treatment at 240° C., heat treatment was performed at a slow cooling temperature of 170° C. while relaxing 5% in the width direction to obtain a biaxially stretched polyester film with a total thickness of 50 μm. The thickness of A layer/B layer/A layer was 5 μm/40 μm/5 μm. The center line average roughness Ra of this polyester film was 400 nm on both sides.
[particle]
Particles to be contained in the release layer-forming composition are shown below.
<Particle 1>
Melamine/silica composite particles: "Optobeads (registered trademark)" 2000M manufactured by Nissan Chemical Industries, Ltd., average particle diameter 2.0 μm, 10% compressive strength 58 MPa.
<Particle 2>
Melamine/silica composite particles: "Optobeads (registered trademark)" 3500M manufactured by Nissan Chemical Industries, Ltd., average particle diameter 3.5 μm, 10% compressive strength 58 MPa.
<Particle 3>
Melamine/silica composite particles: "Optobeads (registered trademark)" 6500M manufactured by Nissan Chemical Industries, Ltd., average particle diameter 6.5 μm, 10% compressive strength 58 MPa.
<Particle 4>
Melamine resin particles: "Eposter (registered trademark)" S12 manufactured by Nippon Shokubai Co., Ltd., average particle diameter 1.2 μm, 10% compressive strength 53 MPa.
<Particle 5>
Benzoguanamine/melamine resin particles: "Eposter (registered trademark)" M30 manufactured by Nippon Shokubai Co., Ltd., average particle diameter 3.0 μm, 10% compressive strength 52 MPa.
<Particle 6>
Benzoguanamine resin particles: "Eposter (registered trademark)" MS manufactured by Nippon Shokubai Co., Ltd., average particle diameter 2.0 μm, 10% compressive strength 52 MPa.
<Particle 7>
Acrylic particles: “Techpolymer (registered trademark)” SSX-102 manufactured by Sekisui Chemical Co., Ltd., average particle diameter 2.0 μm, 10% compressive strength 24 MPa.
<Particle 8>
Hydrophobic silica particles: “Nip Seal (registered trademark)” SS-50B manufactured by Tosoh Silica Co., Ltd., average particle size 1.7 μm.
[Example 1]
On one side of the polyester film 1, the following composition p1 as composition (I) is applied with a gravure coater, pre-dried at 105 ° C., and then dried by heating at 165 ° C. to form a release layer to form a release film. was made. The thickness of the release layer was 0.5 μm.
<Composition p1>
Long-chain alkyl group-containing compound (a): 10 parts by mass of a long-chain alkyl group-containing polyvinyl resin (Lion Specialty Chemicals Co., Ltd. "Piroil" 1050) in terms of solid content Cross-linking agent (b): melamine type 30 parts by mass of a cross-linking agent (Mitsui Chemicals Co., Ltd. "Uban" 28-60) in terms of solid content Particles (c); Acid catalyst (d); 2.1 parts by mass of p-toluenesulfonic acid ("TAYCACURE" AC-707 from Tayca Corporation) in terms of solid content Solvent; Mixed solvent (toluene: methyl ethyl ketone: cyclohexanone = 45: 45: 10 (mass ratio)) to adjust the solid content concentration to 2.0% by mass.
[Example 2]
A release film was produced in the same manner as in Example 1, except that the following composition p2 was used.
<Composition p2>
Composition p1 was prepared in the same manner as composition p1 except that the amount of particles 1 added was changed to 10% by mass with respect to 100% by mass of the total solid content of the composition.
[Example 3]
A release film was produced in the same manner as in Example 1, except that the following composition p3 was used.
<Composition p3>
Composition p1 was prepared in the same manner as composition p1, except that the amount of particles 1 added was changed to 20% by mass with respect to 100% by mass of the total solid content of the composition.
[Example 4]
A release film was produced in the same manner as in Example 1, except that the following composition p4 was used.
<Composition p4>
Composition p1 was prepared in the same manner as composition p1, except that the amount of particles 1 added was changed to 30% by mass with respect to 100% by mass of the total solid content of the composition.
[Example 5]
A release film was produced in the same manner as in Example 1, except that the following composition p5 was used.
<Composition p5>
Composition p1 was prepared in the same manner as composition p1 except that the amount of particles 1 added was changed to 40% by mass with respect to 100% by mass of the total solid content of the composition.
[Example 6]
A release film was produced in the same manner as in Example 1, except that the following composition p6 was used and the thickness of the release layer was changed to 1.0 μm.
<Composition p6>
Composition p1 was prepared in the same manner as composition p1, except that the amount of particles 1 added was changed to 70% by mass with respect to 100% by mass of the total solid content of the composition.
[Example 7]
A release film was produced in the same manner as in Example 1, except that the following composition p7 was used and the thickness of the release layer was changed to 0.7 μm.
<Composition p7>
In the composition p3, it was prepared in the same manner as the composition p3, except that the particles (c) were changed to the particles 2.
[Example 8]
A release film was produced in the same manner as in Example 1, except that the following composition p8 was used and the thickness of the release layer was changed to 1.0 μm.
<Composition p8>
In the composition p3, it was prepared in the same manner as the composition p3, except that the particles (c) were changed to the particles 3.
[Example 9]
A release film was produced in the same manner as in Example 1, except that the following composition p9 was used.
<Composition p9>
The composition p3 was prepared in the same manner as the composition p3, except that the particles (c) were changed to the particles 4.
[Example 10]
A release film was produced in the same manner as in Example 1, except that the following composition p10 was used and the thickness of the release layer was changed to 0.7 μm.
<Composition p10>
The composition p3 was prepared in the same manner as the composition p3, except that the particles (c) were changed to the particles 5.
[Example 11]
A release film was produced in the same manner as in Example 1, except that the following composition p11 was used.
<Composition p11>
The composition p3 was prepared in the same manner as the composition p3, except that the particles (c) were changed to the particles 6.
[Example 12]
A release film was produced in the same manner as in Example 1, except that the following composition p12 was used.
<Composition p12>
The composition p2 was prepared in the same manner as the composition p2, except that the particles (c) were changed to the particles 7.
[Example 13]
A release film was produced in the same manner as in Example 1, except that the following composition p13 was used.
<Composition p13>
In the composition p3, it was prepared in the same manner as the composition p3, except that the particles (c) were changed to the particles 8.
[Example 14]
A release film was produced in the same manner as in Example 1, except that the following composition p14 was used.
<Composition p14>
Long-chain alkyl group-containing compound (a): 10 parts by mass of a long-chain alkyl group-containing polyvinyl resin (Lion Specialty Chemicals Co., Ltd. "Piroil" 1050) in terms of solid content Cross-linking agent (b): melamine type 40 parts by mass of a cross-linking agent ("Uban" 28-60 of Mitsui Chemicals, Inc.) in terms of solid content Particles (c); Acid catalyst (d); 2.8 parts by mass of p-toluenesulfonic acid ("TAYCACURE" AC-707 from Tayca Corporation) in terms of solid content Solvent; mixed solvent (toluene: methyl ethyl ketone: cyclohexanone = 45: 45: 10 (mass ratio)) to adjust the solid content concentration to 2.0% by mass.
[Example 15]
A release film was produced in the same manner as in Example 1, except that the following composition p15 was used.
<Composition p15>
Long-chain alkyl group-containing compound (a): 10 parts by mass of a long-chain alkyl group-containing polyvinyl resin (Lion Specialty Chemicals Co., Ltd. "Piroil" 1050) in terms of solid content Cross-linking agent (b): melamine type 90 parts by mass of a cross-linking agent ("Uban" 28-60 of Mitsui Chemicals, Inc.) in terms of solid content Particles (c); Acid catalyst (d); 6.3 parts by mass of p-toluenesulfonic acid ("TAYCACURE" AC-707 of Tayca Corporation) in terms of solid content Solvent; mixed solvent (toluene: methyl ethyl ketone: cyclohexanone = 45: 45: 10 (mass ratio)) to adjust the solid content concentration to 2.0% by mass.
[Example 16]
A release film was produced in the same manner as in Example 1, except that the following composition p16 was used.
<Composition p16>
Long-chain alkyl group-containing compound (a): 10 parts by mass of a long-chain alkyl group-containing polyvinyl resin (Lion Specialty Chemicals Co., Ltd. "Piroil" 1050) in terms of solid content Cross-linking agent (b): melamine type 20 parts by mass of a cross-linking agent (Mitsui Chemicals Co., Ltd. "Uban" 28-60) in terms of solid content Particles (c); Acid catalyst (d); 1.4 parts by mass of p-toluenesulfonic acid ("TAYCACURE" AC-707 from Tayca Corporation) in terms of solid content Solvent; mixed solvent (toluene: methyl ethyl ketone: cyclohexanone = 45: 45: 10 (mass ratio)) to adjust the solid content concentration to 2.0% by mass.
[Example 17]
A release film was produced in the same manner as in Example 1, except that the following composition p17 was used.
<Composition p17>
・ Long-chain alkyl group-containing compound (a): 10 parts by mass of the following synthetic long-chain alkyl group-containing polyvinyl resin a1 ・ Cross-linking agent (b): Melamine-based cross-linking agent ("Sumimaru" M- 55) is 30 parts by mass in terms of solid content Particles (c); 20% by mass of Particles 1 is added to the total solid content of the composition 100% by mass Acid catalyst (d); p-toluenesulfonic acid (Taika ( Co., Ltd. "TAYCACURE" AC-707) in terms of solid content 2.1 parts by mass solvent; mixed solvent (toluene: methyl ethyl ketone: cyclohexanone = 45: 45: 10 (mass ratio)) solid content concentration 2.0 Adjusted to % by mass.
<Synthesis of long-chain alkyl group-containing polyvinyl resin a1>
200 parts by mass of xylene and 600 parts by mass of otadecyl isocyanate were added to a four-necked flask and heated with stirring. When xylene started to reflux, 100 parts by mass of polyvinyl alcohol (average degree of polymerization: 500, degree of saponification: 88 mol%) was added little by little at intervals of 10 minutes over about 2 hours.

After the addition of polyvinyl alcohol was completed, the mixture was further refluxed for 2 hours to terminate the reaction. When the reaction mixture was cooled to about 80° C. and added to methanol, the reaction product precipitated as a white precipitate. After repeating the operation of adding methanol again for precipitation several times, the precipitate was washed with methanol, dried and pulverized.
[Example 18]
A release film was prepared in the same manner as in Example 1, except that the following composition p18 was used.
<Composition p18>
・ Long-chain alkyl group-containing compound (a); 10 parts by mass of the following synthetic long-chain alkyl group-containing acrylic resin a2 in terms of solid content ・ Crosslinking agent (b); Melamine-based cross-linking agent (manufactured by Sumitomo Chemical Co., Ltd. Sumimar" M-55) is 30 parts by mass in terms of solid content Particles (c); Particle 1 is added at 20% by mass based on the total solid content of the composition 100% Acid catalyst (d); p-toluene sulfone 2.1 parts by mass of acid ("TAYCACURE" AC-707 manufactured by Tayca Co., Ltd.) in terms of solid content solvent; mixed solvent (toluene: methyl ethyl ketone: cyclohexanone = 45:45:10 (mass ratio)) solid content Adjusted to a concentration of 2.0% by mass.
<Synthesis of long-chain alkyl group-containing acrylic resin a2>
70 parts by mass of octadecyl methacrylate, 25 parts by mass of butyl acrylate, 5 parts by mass of acrylic acid, and 150 parts by mass of toluene were placed in a four-necked flask equipped with a stirrer, a nitrogen inlet tube, a condenser, and a rubber septum. was replaced with nitrogen. To this, 0.4 part by mass of 2,2-azobisisobutyronitrile was added under a nitrogen stream, heated to 60° C. and polymerized for 24 hours to obtain a viscous solution of an acrylic polymer. This acrylic polymer is composed of a random copolymer of octadecyl methacrylate, butyl acrylate and acrylic acid, and has an octadecyl group as a long-chain alkyl group in the side chain and a carboxyl group as a functional group. , the number average molecular weight was 96,000.
[Example 19]
A release film was produced in the same manner as in Example 2, except that the base film was changed to PET film 3.
[Comparative Example 1]
A release film was prepared in the same manner as in Example 1, except that the following composition p19 was used.
<Composition p19>
Composition p1 was prepared in the same manner as composition p1, except that the particles (c) were not added.
[Comparative Example 2]
A release film was produced in the same manner as in Comparative Example 1, except that PET film 2 was used as the base film.
[Comparative Example 3]
A release film was prepared in the same manner as in Example 1, except that the following composition p20 was used.
<Composition p20>
Composition p1 was prepared in the same manner as composition p1, except that the cross-linking agent (b) was not added.
[Comparative Example 4]
A release film was produced in the same manner as in Example 1, except that the following composition p21 was used.
<Composition p21>
20 parts by mass of melamine-based resin RP-50 (manufactured by Miwa Laboratory Co., Ltd.), 4 parts by mass of Plascoat DEP Clear (manufactured by Wasin Chemical Industry Co., Ltd.) as a curing agent, and particle 1 as particle (c) was mixed with 200 parts by mass of toluene and 200 parts by mass of cyclohexanone in an amount of 5% by mass with respect to 100% by mass of the total solid content of the composition.
[Example 21]
On one side of the substrate film made of PET film 1, the following composition q1 as composition (II) is applied with a gravure coater, dried at 100 ° C., irradiated with ultraviolet rays at 400 mJ / cm ² and cured to release. Layers were formed to produce a release film. The thickness of the release layer was 0.5 μm.
<Composition q1>
25 parts by mass of a polymerizable long-chain alkyl group-containing compound (α1-1) synthesized below, and 75 parts by mass of dipentaerythritol hexaacrylate (trade name “DPHA” manufactured by Daicel Cytec Co., Ltd.) as a polymerizable compound (β). Parts by mass, 10 parts by mass of a photopolymerization initiator (Irgacure 184 manufactured by Ciba Specialty Chemicals Co., Ltd.) were charged and heated to 100 ° C. and mixed for 1 hour. was added so as to be 5% by mass with respect to the total solid content of 100% by mass, to obtain an active energy ray-curable composition. This composition was prepared with a mixed solvent of toluene and isopropyl alcohol (IPA) (toluene:IPA=3:1 (mass ratio)) to a solid content concentration of 4% by mass.
<Synthesis of polymerizable long-chain alkyl group-containing compound (α1-1)>
A flask equipped with a stirrer and a thermometer was charged with 100 parts by mass of 2-hydroxyethyl acrylate ("BHEA" manufactured by Nippon Shokubai Co., Ltd.) as a (meth)acrylate compound having a hydroxyl group, and diphenylmethane diisocyanate (Japan 240 parts by mass of "Millionate MT" manufactured by Polyurethane Co., Ltd.) and 26 parts by mass of stearyl alcohol ("Conol 30SS" manufactured by Shin Nippon Rika Co., Ltd.) as a higher alcohol are charged, and the temperature is raised to 100° C. for 7 hours. The reaction was carried out while keeping the temperature, and the disappearance of the isocyanate group was confirmed as a result of infrared spectroscopic measurement (IR measurement), and the reaction was terminated.
[Example 22]
A release film was produced in the same manner as in Example 1, except that the following composition q2 was used.
<Composition q2>
Composition q1 was prepared in the same manner as composition q1 except that the amount of particles 1 added was changed to 10% by mass with respect to 100% by mass of the total solid content of the composition.
[Example 23]
A release film was produced in the same manner as in Example 1, except that the following composition q3 was used.
<Composition q3>
Composition q1 was prepared in the same manner as composition q1, except that the amount of particles 1 added was changed to 20% by mass with respect to 100% by mass of the total solid content of the composition.
[Example 24]
A release film was produced in the same manner as in Example 1, except that the following composition q4 was used.
<Composition q4>
Composition q1 was prepared in the same manner as composition q1, except that the amount of particles 1 added was changed to 30% by mass with respect to 100% by mass of the total solid content of the composition.
[Example 25]
A release film was produced in the same manner as in Example 1, except that the following composition q5 was used.
<Composition q5>
Composition q1 was prepared in the same manner as Composition q1, except that the amount of Particles 1 added was changed to 40% by mass with respect to the total solid content of 100% by mass of the composition.
[Example 26]
A release film was produced in the same manner as in Example 1, except that the following composition q6 was used and the thickness of the release layer was changed to 1.0 μm.
<Composition q6>
Composition q1 was prepared in the same manner as composition q1 except that the amount of particles 1 added was changed to 70% by mass with respect to the total solid content of 100% by mass of the composition.
[Example 27]
A release film was produced in the same manner as in Example 1, except that the following composition q7 was used and the thickness of the release layer was changed to 0.7 μm.
<Composition q7>
In composition q3, it was prepared in the same manner as composition q3, except that particles (c) were changed to particles 2.
[Example 28]
A release film was produced in the same manner as in Example 1, except that the following composition q8 was used and the thickness of the release layer was changed to 1.0 μm.
<Composition q8>
In composition q3, it was prepared in the same manner as composition q3, except that particles (c) were changed to particles 3.
[Example 29]
A release film was produced in the same manner as in Example 1, except that the following composition q9 was used.
<Composition q9>
In composition q3, it was prepared in the same manner as composition q3, except that particle (c) was changed to particle 4.
[Example 30]
A release film was produced in the same manner as in Example 1, except that the following composition q10 was used and the thickness of the release layer was changed to 0.7 μm.
<Composition q10>
In composition q3, it was prepared in the same manner as composition q3, except that particles (c) were changed to particles 5.
[Example 31]
A release film was produced in the same manner as in Example 1, except that the following composition q11 was used.
<Composition q11>
In composition q3, it was prepared in the same manner as composition q3, except that particle (c) was changed to particle 6.
[Example 32]
A release film was produced in the same manner as in Example 1, except that the following composition q12 was used.
<Composition q12>
Composition q2 was prepared in the same manner as composition q2, except that particles (c) were changed to particles 7.
[Example 33]
A release film was produced in the same manner as in Example 1, except that the following composition q13 was used.
<Composition q13>
In composition q3, it was prepared in the same manner as composition q3, except that particle (c) was changed to particle 7.
[Example 34]
A release film was produced in the same manner as in Example 21, except that the following composition q14 was used.
<Composition q14>
15 parts by mass of a polymerizable long-chain alkyl group-containing compound (α1-2) synthesized below, and 85 parts of dipentaerythritol hexaacrylate (manufactured by Daicel Cytec Co., Ltd. under the trade name “DPHA”) as a polymerizable compound (β). Parts by mass and 10 parts by mass of a photopolymerization initiator (Irgacure 184 manufactured by Ciba Specialty Chemicals Co., Ltd.) were charged, heated to 100° C. and mixed for 1 hour, and then particles 1 were composed as particles (c). was added so as to be 20% by mass with respect to 100% by mass of the total solid content of the product, to obtain an active energy ray-curable composition. This composition was prepared with a mixed solvent of toluene and isopropyl alcohol (IPA) (toluene:IPA=3:1 (mass ratio)) to a solid content concentration of 4% by mass.
<Synthesis of polymerizable long-chain alkyl group-containing compound (α1-2)>
A flask equipped with a stirrer and a thermometer was charged with 100 parts by mass of 2-hydroxyethyl acrylate (“BHEA” manufactured by Nippon Shokubai Co., Ltd.) as a (meth)acrylate compound having a hydroxyl group, and hexamethylene diisocyanate ( 86 parts by mass of 86 parts by mass of Nippon Polyurethane Co., Ltd. (trade name "HDI") and 46 parts by mass of stearyl alcohol ("Conol 30SS" by Shin Nippon Rika Co., Ltd.) as a higher alcohol were charged, and the temperature was raised to 100 ° C. The reaction was carried out while keeping the temperature for 7 hours, and as a result of IR measurement, it was confirmed that the isocyanate group had disappeared, and the reaction was terminated.
[Example 35]
A release film was produced in the same manner as in Example 21, except that the following composition q15 was used.
<Composition q15>
25 parts by mass of a non-polymerizable long-chain alkyl group-containing compound (α2-1) synthesized below (a compound containing no ethylenically unsaturated group in the molecule), and dipentaerythritol hexaacrylate ( Daicel Cytec Co., Ltd. trade name "DPHA") 45 parts by mass and urethane acrylate (Daicel Cytec Co., Ltd. trade name "KRM8452") 30 parts by mass, a photopolymerization initiator (Ciba Specialty Chemicals Co., Ltd. ) was charged with 10 parts by mass of Irgacure 184), heated to 100° C. and mixed for 1 hour. was added to obtain an active energy ray-curable composition. This composition was prepared with a mixed solvent of toluene and isopropyl alcohol (IPA) (toluene:IPA=3:1 (mass ratio)) to a solid content concentration of 4% by mass.
<Synthesis of non-polymerizable long-chain alkyl group-containing compound (α2-1)>
70 parts by mass of octadecyl methacrylate, 25 parts by mass of butyl acrylate, 5 parts by mass of acrylic acid, and 150 parts by mass of toluene were placed in a four-necked flask equipped with a stirrer, a nitrogen inlet tube, a condenser, and a rubber septum. was replaced with nitrogen. To this, 0.4 part by mass of 2,2-azobisisobutyronitrile was added under a nitrogen stream, heated to 60° C. and polymerized for 24 hours to obtain a viscous solution of an acrylic polymer. This acrylic polymer is composed of a random copolymer of octadecyl methacrylate, butyl acrylate and acrylic acid, and has an octadecyl group as a long-chain alkyl group in the side chain and a carboxyl group as a functional group. , the number average molecular weight was 96,000.
[Example 36]
A release film was produced in the same manner as in Example 22, except that the base film was changed to PET film 3.
[Comparative Example 21]
A release film was prepared in the same manner as in Example 1, except that the following composition q16 was used.
<Composition q16>
Composition q1 was prepared in the same manner as composition q1, except that the particles (c) were not added.
[Comparative Example 22]
A release film was produced in the same manner as in Comparative Example 21, except that PET film 2 was used as the base film.
[evaluation]
The release films of Examples and Comparative Examples prepared above were evaluated according to the measurement method and evaluation method described above. The results are shown in Tables 1-4.

1 Semiconductor element (chip)
2 Substrate 3 Sealing material 4 Release film 10 Lower mold 20 Upper mold

Claims (10)

A release film having a release layer on at least one surface of a base film, wherein the release layer is a cured layer of composition (I) , composition ( IIa ) , or composition (IIb) . release film.
Composition (I); compound (a) containing an alkyl group having 8 or more carbon atoms, a cross-linking agent (b) and particles (c) , wherein the compound (a) containing an alkyl group having 8 or more carbon atoms is A thermosetting polyvinyl resin containing a long-chain alkyl group containing an alkyl group of number 8 or more, wherein the content of the cross-linking agent (b) is 3.0 times or more by mass that of the long-chain alkyl group-containing compound (a) Composition.
Composition (II a ); containing a compound (α) containing an alkyl group having 8 or more carbon atoms and particles (c), wherein the content of the compound (α) containing an alkyl group having 8 or more carbon atoms is An active energy ray-curable composition that is 18% by mass or more and 30% by mass or less with respect to 100% by mass of the total solid content of .
Composition (IIb); containing a compound (α) containing an alkyl group having 8 or more carbon atoms and particles (c), wherein the content of the compound (α) containing an alkyl group having 8 or more carbon atoms is An active energy ray-curable composition having a content of 7% by mass or more and 30% by mass or less with respect to the total solid content of 100% by mass, wherein the compound (α) containing an alkyl group having 8 or more carbon atoms is a polymerizable long chain an alkyl group-containing compound (α1), wherein the polymerizable long-chain alkyl group-containing compound (α1) is
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
A (meth)acrylate compound having one or more (meth)acryloyl groups and one or more hydroxyl groups in the molecule, a polyisocyanate compound having two or more isocyanate groups in the molecule, and a higher alcohol having 8 to 30 carbon atoms A compound obtained by reacting
An active energy ray-curable composition containing one or more compounds selected from the group consisting of The release film according to claim 1, wherein the cross-linking agent (b) in the composition (I) is a melamine-based cross-linking agent. The compound (α) containing an alkyl group having 8 or more carbon atoms in the composition (II) is a polymerizable long-chain alkyl group-containing compound (α1 ), the release film according to claim 1. The mold release according to claim 1 or 3 , wherein the composition (II) further contains a polymerizable compound (β) containing an ethylenically unsaturated group in the molecule and not containing an alkyl group having 8 or more carbon atoms. the film. The release film according to any one of claims 1 to 4 , wherein the particles (c) have an average particle size of 0.5 to 20 µm. The release film according to any one of claims 1 to 5 , wherein the average particle size of the particles (c) is 0.9 times or more the thickness of the release layer. The release film according to any one of claims 1 to 6 , wherein the particles (c) are particles containing melamine resin and/or benzoguanamine resin. The release film according to any one of claims 1 to 7 , wherein the particles (c) are melamine/silica composite particles. The release film according to any one of claims 1 to 8 , wherein the center line average roughness Ra of the release layer surface is 100 nm or more. The release film according to any one of claims 1 to 9 , wherein the release layer has a surface free energy of 20 to 35 mJ/ ^m2 .

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