Resin composition and cured product thereof

Abstract

The object of the present invention is to provide a resin composition that is heat-curable or photocurable, alkali-soluble, has a low dielectric constant and dielectric loss tangent of the cured product, and exhibits high adhesion and glass transition temperature, as well as excellent insulation reliability. [Solution] A resin composition is used that contains a compound represented by the following formula (1) and a compound containing one or more epoxy groups in one molecule. TIFF2026103975000012.tif29170 (In formula (1), each X independently represents a residue of an aromatic or aliphatic tetracarboxylic anhydride with the carboxyl group removed. Y represents a divalent residue of a diol with the hydroxyl group removed. Each Z independently represents a residue of a functional group containing a radically polymerizable double bond. n is the average number of repeating units and is a real number between 0.1 and 20.)

Description

Technical Field

[0004] ,

[0001] The present invention relates to a resin composition and a cured product thereof, and more particularly to a curable resin composition capable of undergoing a thermal or photocuring reaction.

Background Art

[0002] Conventionally, epoxy resins having high adhesiveness and excellent insulation and heat resistance have been widely used for electronic materials such as printed wiring boards. Also, in the resist field, since a development method of removing uncured portions with an alkaline aqueous solution such as an aqueous TMAH (tetramethylammonium hydroxide) solution after causing a curing reaction in specific portions using a photoinitiator is generally employed, alkali solubility is required for resist resins, and a resin obtained by adding acrylic acid to an epoxy group of a polyfunctional epoxy resin and reacting it by half-esterifying an acid anhydride such as tetrahydrophthalic anhydride with an alcoholic hydroxyl group formed is widely used. However, since such a resin contains a large amount of highly polar carboxylic acid in the molecule, the cured product has a high dielectric loss tangent and thus has a problem that it cannot be used for high-frequency applications that require a low dielectric loss tangent.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] Patent Document 1 discloses a polymer compound obtained by reacting a diol compound with a polybasic acid anhydride having two acid anhydride groups in its molecule and a (meth)acrylate having one hydroxyl group in its molecule as a curable resin. Patent Document 2 also discloses a polymer compound obtained by reacting a diol compound with a polybasic acid anhydride having two acid anhydride groups in its molecule and a (meth)acrylate having one hydroxyl group in its molecule as an alkali-soluble curable resin. However, these polymer compounds have problems such as low heat resistance, including the glass transition temperature of the cured product, as well as low adhesion and high dielectric loss tangent. Furthermore, the molecular structures disclosed in these documents contain a large amount of carboxylic acid in the molecule because they are developed with an alkaline aqueous solution after patterning as a resist. When insulation reliability tests are performed using these cured products under high temperature and high humidity conditions, the carboxylic acid corrodes the copper wiring, resulting in insufficient insulation.

[0005] The present invention has been made in view of the above points, and aims to provide a curable resin composition that is soluble in alkaline aqueous solutions, has low dielectric constant and dielectric loss tangent of the cured product, has high heat resistance and adhesive strength, and has excellent insulation reliability under high temperature and high humidity conditions. [Means for solving the problem]

[0006] In other words, the present invention relates to the following [1] to [5]. In this application, "(numerical value 1) to (numerical value 2)" indicates that upper and lower limits are included. [1] A resin composition characterized by containing a compound represented by the following formula (1) and a compound containing one or more epoxy groups in one molecule.

[0007] [ka]

[0008] (In formula (1), each X independently represents a residue of an aromatic or aliphatic tetracarboxylic anhydride excluding the carboxyl group. Y represents a divalent residue of a diol excluding the hydroxyl group. Each Z independently represents a residue of a functional group containing a hydroxyl group and a radically polymerizable double bond. Each R independently represents a hydrogen atom or a methyl group. n is the average value of the number of repeating units and is a real number between 0.1 and 20.)

[0009] [2] A resin composition comprising the resin composition described in the preceding paragraph [1] and a radical initiator. [3] The resin composition according to item [1] or [2] above, comprising a radical-reactive monomer having one or more functional groups in one molecule. [4] A resin composition according to any one of the preceding paragraphs [1] to [3], comprising a radical-reactive polymer having two or more functional groups in one molecule. [5] A cured product of any one of the resin compositions described in the preceding paragraphs [1] through [4]. [Effects of the Invention]

[0010] The resin composition according to the present invention is soluble in an alkaline aqueous solution and can be cured by applying heat or light energy. The cured product of the composition provides a compound with excellent dielectric properties, heat resistance, adhesion, and insulation reliability under high temperature and high humidity conditions. [Modes for carrying out the invention]

[0011] The compound used in the resin composition of the present invention is represented by the following formula (1).

[0012] [ka]

[0013] In formula (1), each X independently represents a residue of an aromatic or aliphatic tetracarboxylic anhydride from which the carboxyl group has been removed. Y represents a divalent residue of a diol compound from which the hydroxyl group has been removed. Each Z independently represents a residue of a compound containing one hydroxyl group and one radically polymerizable double bond. n is the average value of the number of repeating units and is a real number between 0.1 and 20. The compound represented by formula (1) may be a high molecular weight polymer compound.

[0014] The value of n in equation (1) above can be determined by GPC (gel permeation chromatography) measurement.

[0015] The method for producing the compound represented by formula (1) above is not particularly limited, but it can be obtained as follows: Intermediate 1 is obtained by adding less than 1 mole of a diol to 1 mole of an aromatic or aliphatic tetracarboxylic dianhydride. The compound represented by formula (1) above is obtained by reacting the carboxylic acid anhydride present at the end of the obtained intermediate 1 with a predetermined amount of a compound having one hydroxyl group and one radically polymerizable double bond in one molecule.

[0016] Examples of the aromatic or aliphatic tetracarboxylic dianhydrides include 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,5-cyclohexanetetracarboxylic dianhydride, 4,4'-oxydiphthalic anhydride, pyromellitic anhydride, 4,4'-sulfonyldiphthalic anhydride, 4,4'-carbonyldiphthalic anhydride, 4,4'-biphthalic anhydride, 3,4'-biphthalic anhydride, 4,4'-(ethyne-1,2-)diphthalic anhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride, 3,4'-oxydiphthalic anhydride, 9,9'-bis(3,4-dicarboxyphenyl)fluorene dianhydride, ethylene glycol bis(anhydrotrimellitate), bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid)1,4-phenylene, p-biphenylene bis(trimellitic anhydride), and the like.

[0017] Examples of the diols include ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, 3,3-dimethyl-1,5-pentanediol, 1,9-nonanediol, 1,4-hexanedimethanol, polyethylene glycol, 1,16-hexadecanediol, 1,17-heptadecanediol, 1,18-octadecanediol, 1,20-eicosanediol, a dimer diol having 36 carbon atoms, and the like. Among them, a dimer diol having 36 carbon atoms is particularly preferred. The dimer diol includes those in which the double bond derived from the unsaturated fatty acid as the raw material remains as it is and those that are hydrogenated. From the aspect of preventing deterioration of the dielectric properties due to oxidation of the double bond, the hydrogenated one is preferred.

[0018] The dimer diol is obtained by converting two carboxy groups of dimer acid, which is a dimer of unsaturated fatty acids such as oleic acid, into primary hydroxyl groups. The following shows a non-limiting general formula of the dimer diol (in each formula, m + n is preferably 6 to 17, p + q is preferably 8 to 19, and the dashed line represents a carbon-carbon single bond or a carbon-carbon double bond).

[0019] [Chemical formula]

[0020] Intermediate 1 of the above compound is represented by the following formula (3) and can be obtained by charging less than 1 mole of a diol compound with respect to 1 mole of an aromatic or aliphatic tetracarboxylic dianhydride and subjecting it to a half esterification reaction.

[0021] [Chemical formula]

[0022] In formula (4), X, Y, and n represent the same meanings as in formula (1).

[0023] In the above reaction, the amount of diol compound used is preferably 0.4 to 0.95 moles per mole of aromatic tetracarboxylic dianhydride, and more preferably 0.5 to 0.9 moles. A solvent is preferably used in the reaction, and usable solvents include toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, propylene glycol monomethyl ether acetate, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, and γ-butyrolactone. The amount of solvent used is preferably 0 to 300% by mass relative to the solid content, and more preferably 20 to 200% by mass. A catalyst may also be used to expedite the reaction. Examples of quaternary ammonium salts that can be used as catalysts include pyridine, dimethylaminopyridine, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, benzyltriethylammonium chloride, benzyltriethylammonium bromide, benzyltripropylammonium chloride, benzyltripropylammonium bromide, benzyltrimethylphosphonium chloride, benzyltrimethylphosphonium bromide, benzyltriethylphosphonium chloride, benzyltriethylphosphonium bromide, benzyltripropylphosphonium chloride, benzyltripropylphosphonium bromide, tetraphenylphosphonium chloride, and tetraphenylphosphonium bromide. The amount of catalyst used is preferably 0.01 to 5% of the total mass of the reaction substrate, and more preferably 0.05 to 3%.

[0024] Regarding the ratio of aromatic tetracarboxylic dianhydride to diol compound, a higher proportion of the diol compound results in a larger average molecular weight of the polymer intermediate, while a lower proportion results in a smaller average molecular weight. However, both terminal residues of the intermediate are always acid anhydrides. The reaction temperature is usually 20-150°C, preferably 30-140°C, and the reaction time is usually 0.5-30 hours, preferably 1-20 hours. The reaction can be terminated by GPC (gel permeation chromatography) when the molecular weight stops increasing beyond a certain value.

[0025] By reacting intermediate 1 with a predetermined amount of a compound having one hydroxyl group and one radically polymerizable double bond in one molecule, the compound of the present invention represented by formula (1) can be obtained.

[0026] Examples of compounds having one radically polymerizable double bond and one hydroxyl group in one molecule include 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl methacrylate, 2-hydroxybutyl acrylate, N-(2-hydroxyethyl)acrylamide, N-(2-hydroxyethyl)methacrylamide, N-(2-hydroxypropyl)acrylamide, N-(2-hydroxypropyl)methacrylamide, N-(1,1-dimethyl-3-hydroxybutyl)acrylamide, N-(1,1-dimethyl-3-hydroxybutyl)methacrylamide, hydroquinone monomethacrylate, hydroquinone monoacrylate, hydroquinone monomethacrylamide, hydroquinone monoacrylamide, 1,4-cyclohexanedimethanol monomethacrylate, 1,4-cyclohexanedimethanol monoacrylate, and 2-hydroxyethyl vinyl ether.

[0027] The amount of compound having one radically polymerizable double bond and one hydroxyl group per molecule added is equimolar or greater than the equivalent amount of acid anhydride groups present in intermediate 1, preferably 1.01 to 2 times, and more preferably 1.05 to 1.5 times. The reaction involves adding a predetermined amount of compound having one radically polymerizable double bond and one hydroxyl group per molecule to the reaction solution obtained from intermediate 1, thereby inducing an addition reaction. The reaction temperature is usually 20 to 150°C, preferably 30 to 140°C, and the reaction time is usually 0.5 to 30 hours, preferably 1 to 20 hours. The progress of the reaction can be confirmed by the acid value. After the reaction is complete, the unreacted compound having one radically polymerizable double bond and one hydroxyl group per molecule can be removed by dropping the reaction solution into a poor solvent such as methanol and precipitating only the compound of the present invention.

[0028] The resin composition of the present invention contains a compound represented by formula (1) and a compound having one or more epoxy groups in one molecule. It may also contain a radical polymerization initiator, and as the radical initiator, a thermal radical initiator or a photoradical initiator can be used.

[0029] Compounds containing one or more epoxy groups in one molecule include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, 1,4-butanediol diglycidyl ether, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, phenyl glycidyl ether, resorcinol diglycidyl ether, (3,4-epoxycyclohexane)methyl 3,4-epoxycyclohexyl carboxylate, 4-vinylcyclohexene oxide, 1,3,5-triglycidyl isocyanuric acid, 4,4'-biphenol diglycidyl ether, 3,3',5,5'-tetramethyl-4,4'-biphenol diglycidyl ether, and 1-methyl-4-(2-methyloxirane). Examples include (-2-yl)-7-oxabicyclo[4.1.0]heptane, 3,3'-bi-7-oxabicyclo[4.1.0]heptane, 1,2:5,6-diepoxahydroindan, 2-(7-oxabicyclo[4.1.0]heptan-3-yl)oxirane, bis[(7-oxabicyclo[4.1.0]heptan-3-yl)methyl] hexanediate, dicyclopentadiene diepoxide, poly[(2-oxyranyl)-1,2-cyclohexanediol]2-ethyl-2-(hydroxymethyl)-1,3-propanediol ether, phenol novolac type epoxy resin, cresol novolac type epoxy resin, phenol-dicyclopentadiene condensation novolac type epoxy resin, biphenyl novolac type epoxy resin, N,N-diglycidylaniline, and N,N-diglycidylmethylaniline.

[0030] The amount of compound containing one or more epoxy groups in one molecule is preferably 0.1 to 1 times the epoxy equivalent amount per equivalent of the carboxylic acid of the compound of the present invention.

[0031] Preferred thermal radical initiators include peroxides such as benzoyl peroxide, cumene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexine-3, di-t-butyl peroxide, t-butylcumyl peroxide, α,α-bis(t-butylperoxy-m-isopropyl)benzene, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, dicumyl peroxide, di-t-butylperoxyisophthalate, t-butylperoxybenzoate, 2,2-bis(t-butylperoxy)butane, 2,2-bis(t-butylperoxy)octane, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, di(trimethylsilyl)peroxide, and trimethylsilyltriphenylsilyl peroxide.

[0032] Examples of preferred photoradical initiators include benzoin, benzoin methyl ether and its alkyl ethers such as benzoin, benzoin ethyl ether; acetophenones such as acetophenone, 2,2-dimethoxy-2-phenylacetophenone and 1,1-dichloroacetophenone; anthraquinones such as anthraquinone, 2-methylanthraquinone, 2-amylanthraquinone, 2-t-butylanthraquinone and 1-chloroanthraquinone; thioxanthones such as 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone and 2-chlorothioxanthone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzo Examples include benzophenones such as phenone, 4,4'-bis(diethylamino)benzophenone, and 4,4'-bis(dimethylamino)benzophenone; 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1; acylphosphine oxides and xanthones, and oxime esters such as 1,2-octanedione, 1-[4-(phenylthio)phenyl]-,2-(o-benzoyl oxime), ethanone, and 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-,1-(o-acetyl oxime).

[0033] The amount of radical initiator in the above resin composition is usually 0.1 to 10 parts by mass, preferably 0.1 to 8 parts by mass, based on 100 parts by mass of the total resin components, such as the compound represented by formula (1) and the radical-reactive monomer, which is an optional component described later.

[0034] The resin composition of the present invention may also contain radical-reactive monomers. By using radical-reactive monomers in combination, the reactivity of the resin composition of the present invention and the heat resistance of the cured product can be improved. Preferably, radical-reactive monomers have one or more functional groups, and specific examples include acenaphthylene, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, neopentyl glycol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, glycerin dimethacrylate, 2-hydroxy-3-acryloyloxypropyl methacrylate, bisphenol A ethylene oxide adduct methacrylate, trimethylolpropane trimethacrylate, tricyclodecane dimethanol dimethacrylate, glycerin dimethacrylate, trimethylolpropane trimethacrylate, ethoxylated isocyanurate triacrylate, ε-caprolactone modified tris-(2-acryloxyethyl) isocyanurate, pentaerythritol triacrylate, ditrimethylolpropane tetraacrylate, ethoxylated pentaerythritol tetraacrylate, pentaerythritol tetraacrylate, dipentaerythritol polyacrylate, dipentaerythritol hexaacrylate, triallyl isocyanurate, triallyl cyanurate, divinylbenzene, divinyl isophthalate, N-phenyl-maleimide, N-phenyl-methylmaleimide, N-phenyl-chloromaleic acid Mido, Np-chlorophenyl-maleimide, Np-methoxyphenyl-maleimide, Np-methylphenyl-maleimide, Np-nitrophenyl-maleimide, Np-phenoxyphenyl-maleimide, Np-phenylaminophenyl-maleimide, Np-phenoxycarbonylphenyl-maleimide, 1-maleimide-4-acetoxysuccinimide-benzene, 4-maleimide-4'-acetoxysuccinimide-diphenylmethane, 4-maleimide-4'-acetoxysuccinimide- Examples include diphenyl ether, 4-maleimide-4'-acetamide-diphenyl ether, 2-maleimide-6-acetamide-pyridine, 4-maleimide-4'-acetamide-diphenylmethane, and Np-phenylcarbonylphenyl-maleimide N-ethylmaleimide, N-2,6-xylylmaleimide, N-cyclohexylmaleimide, N-2,3-xylylmaleimide, xylylmaleimide, 2,6-xylenemaleimide, and 4,4'-bismaleimide-diphenylmethane. These radical-reactive monomers may be used individually or in combination of two or more.

[0035] The resin composition of the present invention may also contain a radical-reactive polymer. By using a radical-reactive polymer, the adhesion and heat resistance of the cured product of the resin composition of the present invention can be improved. The radical-reactive polymer is preferably one having two or more functional groups, and specific examples include a copolymer of styrene and butadiene, a modified polyphenylene ether resin, or an imide-extended bismaleinimide.

[0036] The copolymer of styrene and butadiene may be a random copolymer (commonly known as SBR) or a block copolymer. Alternatively, a copolymer obtained by hydrogenating the double bonds derived from butadiene in a block copolymer to create a saturated hydrocarbon (commonly known as SEBS resin) may also be used. The ratio of styrene to butadiene in the polymer is usually 10:90 to 90:10. The number-average molecular weight is usually 1,000 to 100,000. Specific examples of SBR products include Clay Valley's Ricon100, Ricon181, and Ricon184, while specific examples of SEBS resin products include Asahi Kasei Corporation's ToughTec series and Kraton's G Polymer series.

[0037] Examples of modified polyphenylene ether resins include those having methacryloyl groups, acryloyl groups, or vinyl groups at both ends of the molecule and having a number average molecular weight of 1,000 to 10,000. Specific examples include the compound represented by formula (4) below (product name SA9000, manufactured by SABIC Japan LLC), which has methacryloyl groups at both ends and a number average molecular weight of approximately 1,700, or the compound represented by formula (5) below (product name OPE-2St 1200 or OPE-2St 2200, manufactured by Mitsubishi Gas Chemical Company, Ltd.), which has vinyl groups at both ends and a number average molecular weight of approximately 1,200 or 2,200.

[0038] [ka]

[0039] [ka]

[0040] The imide-extended bismaleinimide resin used in the present invention can be obtained by known methods described in Japanese Patent Publication No. 5328006, etc. Specifically, it can be obtained by carrying out a dehydration condensation reaction of an aliphatic diamine and an aromatic or aliphatic tetracarboxylic diacid anhydride in an excess molar ratio in an organic solvent using an acid catalyst, then dehydrating condensation of the amino group present at the polymer terminal with maleic anhydride, and removing the catalyst by washing with water.

[0041] Specific examples of aliphatic diamines include 1,10-diaminodecane, 1,12-diaminododecane, dimeramine, 1,2-diamino-2-methylpropane, 1,2-diaminocyclohexane, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,7-diaminoheptane, 1,8-diaminomentane, 1,8-diaminooctane, 1,9-diaminononane, 3,3'-diamino-N-methyldipropylamine, diaminomaleonitrile, 1,3-diaminopentane, and 9,10-diaminophenanthrene, but dimeramine is particularly preferred.

[0042] Specific examples of aromatic or aliphatic tetracarboxylic dianhydrides include pyromellitic anhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, bicyclo(2.2.2)octo-7-ene-2,3,5,6-tetracarboxylic dianhydride, diethylenetriaminepentaacetic acid dianhydride, ethylenediaminetetraacetic acid dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, and 3,3',4 ,4'-biphenyltetracarboxylic acid dianhydride, 4,4'-oxydiphthalic anhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic acid dianhydride, 2,2'-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride, 4,4'-bisphenol A diphthalic acid anhydride, 5-(2,5-dioxytetrahydro)-3-methyl-3-cyclohexene-1,2-dicarbon anhydride, ethylene glycol bis(trimellitic acid anhydride), hydroquinone diphthalic acid anhydride, 1,2,3,4-cyclobuta Dihydrofurantetracarboxylic acid dianhydride (CBDA), 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, 1,1'-bicyclohexane-3,3',4,4'-tetracarboxylic acid-3,4:3',4'-dianhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3 Examples include 4-tetrahydronaphthalene-1,2-dicarboxylic acid anhydride, 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic acid dianhydride, bicyclo[2.2.2]octo-7-ene-2,3,5,6-tetracarboxylic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic acid dianhydride, and 3,5,6-tricarboxy-2-norbornaneacetic acid dianhydride, but pyromellitic anhydride and 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride are particularly preferred. A specific product name is BMI-3000 from Designer Molecules Inc.

[0043] Furthermore, since the compound represented by formula (1) above is alkali-soluble, it can be used in combination with conventional alkali-soluble curable resins. Specific examples of alkali-soluble curable resins include those obtained by adding acrylic acid to the epoxy group of a polyfunctional epoxy resin, and then reacting the resulting alcoholic hydroxyl group with a polybasic acid anhydride to form a half-ester.

[0044] Examples of polyfunctional epoxy resins include bisphenol A type epoxy resin, bisphenol F epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, aralkylphenol novolac type epoxy resin, biphenyl novolac type epoxy resin, and triphenylmethane type epoxy resin. Examples of polybasic acid anhydrides include dibasic acid anhydrides such as maleic anhydride, succinic anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and chloridenic anhydride, as well as polybasic acid anhydrides such as trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, and biphenyltetracarboxylic anhydride.

[0045] The resin composition of the present invention may also contain an organic solvent. Specific examples of organic solvents include aromatic solvents such as toluene and xylene; ether solvents such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ether monoacetate, and propylene glycol monobutyl ether; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, and cyclohexanone; lactones such as γ-butyrolactone and γ-valerolactone; amide solvents such as N-methylpyrrolidone (NMP), N,N-dimethylformamide (DMF), N,N-dimethylacetamide, and N,N-dimethylimidazolidinone; and sulfones such as tetramethylene sulfone. The content of the organic solvent in the resin composition of the present invention is usually 90% by mass or less, preferably 30 to 80% by mass.

[0046] The resin composition of the present invention may be used in combination with a polymerization inhibitor to improve storage stability. The polymerization inhibitor that can be used in combination is not particularly limited as long as it is generally known, and examples include quinones such as hydroquinone, methylhydroquinone, p-benzoquinone, chloranil and trimethylquinone, aromatic diols, and di-t-butylhydroxytoluene.

[0047] The resin composition of the present invention can be used by adding fillers and additives in amounts that do not impair its original properties, in order to impart desired performance depending on its application. The fillers may be in the form of fibers or powders, and examples include silica, carbon black, alumina, talc, mica, glass beads, glass hollow spheres, etc.

[0048] The resin composition of the present invention may also be used in combination with flame retardant compounds, additives, etc. These are not particularly limited as long as they are commonly used. For example, flame retardant compounds include bromine compounds such as 4,4-dibromoviphenyl, phosphate esters, melamine phosphate, phosphorus-containing epoxy resins, nitrogen compounds such as melamine and benzoguanamine, oxazine ring-containing compounds, and silicon-based compounds. Additives such as ultraviolet absorbers, antioxidants, photopolymerization initiators, fluorescent whitening agents, photosensitizers, dyes, pigments, thickeners, lubricants, defoamers, dispersants, leveling agents, and glossing agents can be used in appropriate combinations as desired.

[0049] The resin composition of the present invention can be used by coating or impregnating various substrates. For example, when using a thermal radical initiator, it can be used as an interlayer insulating layer for multilayer printed circuit boards by coating it onto a PET film, as a coverlay by coating it onto a polyimide film, or as resin-coated copper foil by coating and drying it onto copper foil. It can also be used as a prepreg for printed wiring boards or CFRP by impregnating it with glass cloth, glass paper, carbon fiber, or various nonwoven fabrics. Furthermore, by using a photoradical initiator, it is possible to develop a specific pattern by curing only the parts irradiated with light of a specific wavelength and washing the other parts with an alkaline aqueous solution, and it can be used as various resists such as redistribution layers for semiconductors and solder resists for printed circuit boards.

[0050] The interlayer insulating layer, coverlay, resin-coated copper foil, prepreg, etc. of the present invention can be cured by heating and pressing them using a hot press machine or the like. [Examples]

[0051] The present invention will be described in further detail below with reference to examples and comparative examples. Unless otherwise specified, parts refer to parts by mass. The present invention is not limited to these examples.

[0052] [Synthesis of the compound represented by formula (1)] In a flask equipped with a thermometer, condenser, nitrogen gas inlet tube, and stirrer, 21.52 parts of hydrogenated dimergol (product name Pripol 2033, Cargill), 26.0 parts of 4,4'-(4,4'-isopropylidene diphenoxy) diphthalic anhydride, 50 parts of propylene glycol monomethyl ether acetate (PGMEA), and 0.05 parts of pyridine were added and reacted at 130°C for 3 hours to obtain a PGMEA solution of intermediate 1 represented by the following formula (6). The value of n calculated from the number-average molecular weight of 3,100 obtained by GPC was 3.9.

[0053] [ka]

[0054] The temperature of the solution of intermediate 1 was lowered to 110°C, 2.6 parts of 2-hydroxyethyl methacrylate were added while bubbling air into the system, and the reaction was carried out at 110°C for 12 hours. Then, the temperature in the system was lowered to room temperature, 100 parts of methanol were added, and after stirring, the system was allowed to stand to precipitate the high molecular weight compound. The upper methanol layer was decanted to remove pyridine and trace amounts of unreacted low molecular weight compounds. An additional 50 parts of PGMEA were added to the lower PGMEA layer, and the methanol dissolved in the system was removed by evaporation. By adjusting the amount of PGMEA, 114 parts of a 35% PGMEA solution of the compound with the structure represented by formula (7) below were obtained. The acid value of this polymer was measured to be 112 mg KOH / g.

[0055] [ka]

[0056] [Example 1, Comparative Example 1 (Preparation of Resin Composition)] As Example 1, resin composition 1 of the present invention was obtained by uniformly mixing 10 parts of the resin solution obtained in the above synthesis example with 0.07 parts of dicumyl peroxide and 0.28 parts of (3,4-epoxycyclohexane)methyl 3,4-epoxycyclohexyl carboxylate (product name: Celoxide 2021P, manufactured by Daicel Corporation) as radical initiators. As a comparative example, resin composition 2 was obtained by preparing a composition in the same manner as in Example 1, except that (3,4-epoxycyclohexane)methyl 3,4-epoxycyclohexyl carboxylate was not added.

[0057] [Example 2, Comparative Example 2] (Evaluation of alkaline solubility) 0.16 parts of the resin compositions obtained in Example 1 and Comparative Example 1 were each placed in 20 ml sample tubes, left at 110°C for 10 minutes to evaporate the solvent, and then 10 ml of 2.38% aqueous solution of TMAH (tetramethylammonium hydroxide) was added. The time until complete dissolution was measured.

[0058] [Table 1]

[0059] (Evaluation of dielectric properties, heat resistance, and adhesive properties of cured resin compositions) Using an applicator, resin compositions 1 and 2 obtained in Example 1 and Comparative Example 1 were applied to a mirror surface of an 18 μm thick copper foil to a thickness of 150 μm, respectively. The solvent was dried by heating at 110°C for 10 minutes to obtain copper foil having a film-like adhesive made of the resin composition. The film-like adhesive on the copper foil obtained above was heated and cured in a vacuum oven at 225°C for 2 hours, and then the copper foil was removed by immersion in an etching solution to obtain cured film-like adhesive products with a thickness of 50 μm that could be handled as films. The dielectric constant and dielectric loss tangent of the obtained cured products at 10 GHz were measured using the cavity resonance method with a network analyzer 8719ET (Agilent Technologies). The glass transition temperature was also measured for the same samples using a thermomechanical analyzer (TMA). The results are shown in Table 2.

[0060] Using an applicator, resin compositions 1 and 2 were applied to a matte surface of a 12 μm thick, low-roughness copper foil for high-frequency applications (CF-T4X-SV: manufactured by Fukuda Metal Foil & Powder Co., Ltd.) to a thickness of 50 μm, respectively. The solvent was dried by heating at 130°C for 10 minutes, thereby obtaining copper foil with a film-like adhesive made of the resin composition. The matte surface of the same copper foil was placed on top of the adhesive surface of the resin-coated copper foil obtained above, and the two were heated and cured in a vacuum press at a pressure of 3 MPa and 225°C for 2 hours. The 90° peel strength (adhesion strength) between the copper foils was then measured using an Autograph AGX-50 (manufactured by Shimadzu Corporation). The results are shown in Table 2.

[0061] [Table 2]

[0062] (Evaluation of insulating reliability of cured resin compositions) Resin compositions 1 and 2 obtained in Example 1 and Comparative Example 1 were applied to six pairs of comb-shaped electrodes (18 μm thick copper foil) with a line-and-space of 50 μm / 50 μm, respectively, so that all electrodes were covered to a thickness of 150 μm. The electrodes were heated at 130°C for 10 minutes to dry the solvent, and then heated and cured in a vacuum oven at 225°C for 2 hours to obtain a test circuit insulated between electrodes by cured resin composition 1 or 2 with a thickness of 50 μm. A voltage of 50 V was applied between these electrodes and the circuit was placed in a chamber at 130°C and 85% relative humidity, and the change in insulation resistance was observed. In Example 1, the resistance value of all electrodes never fell below 10⁹ ohms for 168 hours from the start of the test, but in Comparative Example 1, the resistance value of the electrodes was 10⁷ ohms immediately after the start of the test, and all electrodes became conductive after 3 hours.

[0063] As described above, the resin composition of the present invention exhibited good solubility in alkaline aqueous solutions, and further demonstrated excellent dielectric properties, heat resistance, adhesion, and insulation reliability.

Claims

1. A resin composition characterized by containing a compound represented by the following formula (1) and a compound containing one or more epoxy groups in one molecule. 【Chemistry 1】 (In formula (1), each X independently represents a residue of an aromatic or aliphatic tetracarboxylic anhydride from which the carboxyl group has been removed. Y represents a divalent residue of a diol from which the hydroxyl group has been removed. Each Z independently represents a residue of a functional group containing a radically polymerizable double bond. n is the average number of repeating units and is a real number between 0.1 and 20.)

2. A resin composition comprising the resin composition according to claim 1 and a radical initiator.

3. The resin composition according to claim 2, comprising a radical-reactive monomer having one or more functional groups in one molecule.

4. The resin composition according to claim 2, comprising a radical-reactive polymer having two or more functional groups in one molecule.

5. A cured product of the resin composition according to any one of claims 2 to 4.

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