Hardening polymeric compounds and resin compositions containing such compounds

Abstract

To provide a polymer compound which is excellent in solubility to a low-boiling solvent such as toluene, and a cured product of the polymer compound which has flexibility enough to form a film, and has high adhesion to low-roughness copper foil, a low dielectric constant and dielectric loss tangent, and a low efficient of linear expansion.SOLUTION: A polymer compound is represented by the following formula (1). In formula (1), R1, R2, R3 and R4 independently represent a methyl group, an ethyl group, an isopropyl group or a tertiary butyl group; X each independently represents an acetyl group or a partial structure represented by the following formula (2), but 5% or more of the plurality of X has a structure represented by formula (2); Y represents a residue obtained by removing two amino groups from a diamino group; and n is an average value of a number of repeating units and is within a range of 1 to 100.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polymer compound that can be easily formed into a film by casting a solution onto a substrate, that can undergo a thermal or photo-curing reaction when used in combination with a radical initiator, and that produces a cured product with excellent dielectric properties, adhesiveness, and heat resistance. [Background technology]

[0002] Phenoxy resin is a polymeric compound with a very high molecular weight obtained by polymerizing a difunctional epoxy resin and a difunctional phenolic compound. By adding this phenoxy resin, it is possible to form general epoxy resin compositions and radically polymerizable compositions into film form, and it is therefore used in a wide range of fields as an important component of film adhesives, particularly in the electrical and electronic fields where it is used for interlayer insulation layers in printed circuit boards and resin-coated copper foils.

[0003] Although cured products of resin compositions containing added phenoxy resin have excellent adhesive properties and film-forming ability, they have low heat resistance and, moreover, high dielectric constants and dielectric dissipation factors (at a frequency of 1 GHz, the dielectric constant is about 3.5 and the dielectric dissipation factor is about 0.03), making them unsuitable for use in electronic devices, which have seen the recent increase in signal response speed. Polymeric fluorine compounds such as polytetrafluoroethane (PTFE) (Patent Document 1) and liquid crystal polymers (Patent Document 2) are generally known as resins with excellent dielectric properties, but these resins have extremely low compatibility with other resins and insufficient adhesive properties.

[0004] Aromatic bismaleimides are known for their excellent heat resistance and dielectric properties. However, they generally have poor solvent solubility, dissolving only in high-boiling aprotic polar solvents such as NMP and DMF. This makes them difficult to use in electronic materials, which use low-boiling solvents such as toluene and methyl ethyl ketone. Furthermore, their cured products are generally rigid and inflexible, making them difficult to use in film applications. Patent Document 3 discloses a method for improving solvent solubility by subjecting aromatic bismaleimides to a Michael addition reaction with aliphatic diamines to achieve high molecular weight. However, this polymeric compound composed of a bismaleimide compound and a diamine compound suffers from poor stability and a tendency to gel due to the reactivity of the secondary amines remaining in the structure with the maleimide groups at the molecular terminals. Patent Documents 4 and 5 disclose a method for improving stability by reacting the secondary amines in the addition reaction product of bismaleimide and diamine with acetic anhydride to acetylate them. However, the resins obtained by this method have an extremely high linear expansion coefficient when cured, making them unsuitable for applications such as electronic devices, which require high reliability. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-001274 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-060449 [Patent Document 3] Japanese Patent Application Laid-Open No. 2006-241300 [Patent Document 4] Patent No. 6948907 [Patent Document 5] Publication US8637611 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in view of the above points, and aims to provide a polymer compound having excellent solubility in low-boiling point solvents such as toluene, and a cured product of the polymer compound having sufficient flexibility to be formed into a film, high adhesion to low-roughness copper foil, low dielectric constant and dielectric dissipation factor, and low linear expansion coefficient. [Means for solving the problem]

[0007] As a result of extensive research, the present inventors have found that the above problems can be solved by using a resin composition containing a polymer compound having a specific structure, and have thus completed the present invention. That is, the present invention is (1) The following formula (1)

[0008] [ka]

[0009] In formula (1), R1, R2, R3, and R4 each independently represent a methyl group, an ethyl group, an isopropyl group, or a tertiary butyl group. X each independently represents an acetyl group or a group represented by the following formula (2):

[0010] [ka]

[0011] (In formula (2), R5 represents a hydrogen atom or a methyl group.) where 5% or more of the plural X's are structures represented by formula (2). Y represents a residue obtained by removing two amino groups from a diamino compound. n is the average number of repeating units and is in the range of 1 to 100. (2) A resin composition containing the polymer compound according to the above item (1) and a radical initiator. (3) The resin composition according to the above item (2), which contains a radical-reactive monomer having a radical-reactive functional group. (4) The resin composition according to the above item (2), which contains a radical-reactive polymer having two or more radical-reactive functional groups in one molecule. (5) A film-like adhesive comprising the resin composition according to any one of (2) to (4) above, and (6) A cured product of the resin composition according to any one of (2) to (4) above or the film-like adhesive according to (5) above. Regarding. [Effects of the Invention]

[0012] The polymer compound according to the present invention and a resin composition containing the polymer compound can be cured by using a radical initiator in combination with heat or light energy, and the cured resin composition can provide a polymer compound having excellent dielectric properties, adhesiveness, and heat resistance. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of the present invention will be described. The polymer compound of the present inventors is a reaction product of acetic anhydride and secondary amino groups remaining in a reaction product of 5% or more but less than 100% of secondary amino groups in a copolymer (C) of a diamino compound (A) (hereinafter simply referred to as "compound (A)") and a bismaleimide compound (B) (hereinafter simply referred to as "compound (B)") having a specific structure in an excess molar amount relative to compound (A) and isocyanate groups in a compound (D) (hereinafter simply referred to as "compound (D)") having an isocyanate group and a (meth)acrylic group. First, the copolymer (C), which is an intermediate raw material for the polymer compound of the present invention, will be explained.

[0014] The copolymer (C) is a copolymerization reaction product (Michael addition reaction product) of the compound (A) and a molar excess of the compound (B) over the compound (A). The compound (A) used as the raw material for the copolymer (C) is not particularly limited as long as it is a compound having two amino groups in one molecule, and specific examples thereof include 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, hexamethylenediamine, 1,8-diaminooctane, 1,10-diaminodecane, 1,12-diaminododecane, 4,4'-methylenebiscyclohexanediamine, 1,2-cyclohexanediamine, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, 1,3-bis(aminomethyl)cyclohexane, 1,4 -Bis(aminomethyl)cyclohexane, isophoronediamine, norbornenediamine, dimer diamine, 3,3'-diamino-N-methyldipropylamine, diaminomaleonitrile, 1,3-diaminopentane, 9,10-diaminophenanthrene, 4,4'-diaminooctafluorobiphenyl, 3,5-diaminobenzoic acid, 3,7-diamino-2-methoxyfluorene, 4,4'-diaminobenzophenone, 3,4-diaminobenzophenone, 3,4-diaminotoluene, 2,6-diaminoanthraquinone, 2,6-diaminotoluene, 2,3- Diaminotoluene, 1,8-diaminonaphthalene, 2,4-diaminotoluene, 2,5-diaminotoluene, 1,4-diaminoanthraquinone, 1,5-diaminoanthraquinone, 1,5-diaminonaphthalene, 1,2-diaminoanthraquinone, 2,4-cumenediamine, 1,3-bisaminomethylbenzene, 1,3-bisaminomethylcyclohexane, 2-chloro-1,4-diaminobenzene, 1,4-diamino-2,5-dichlorobenzene, 1,4-diamino-2,5-dimethylbenzene, 4,4'-diamino-2,2'-bistrifluoromethylbiphenyl Phenyl, bis(amino-3-chlorophenyl)ethane, bis(4-amino-3,5-dimethylphenyl)methane, bis(4-amino-3,5-diethylphenyl)methane, 2,3-diaminonaphthalene, bis(4-amino-3-methylphenyl)methane, bis(4-amino-3-ethylphenyl)methane, 4,4'-diaminophenyl sulfone, 3,3'-diaminophenyl sulfone, 2,2-bis(4,(4-aminophenoxy)phenyl)sulfone, 2,2-bis(4-(3-aminophenoxy)phenyl)sulfone, 4,4'-oxydianiline, 4,4'-Diaminodiphenyl sulfide, 3,4'-oxydianiline, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 1,3-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-diamino-3,3'-dimethylbiphenyl, 4,4'-diamino-3,3'-dimethoxybiphenyl, 9,9-bis(4-aminophenyl)fluorene, 1,3-bis(4-aminophenoxy)-2,2-dimethylpropane, 1,3- Examples of suitable bis(4-aminophenoxy)propane include bis(4-aminophenoxy)butane, 1,4-bis(4-aminophenoxy)butane, 1,5-bis(4-aminophenoxy)butane, 2,3,5,6-tetramethyl-1,4-phenylenediamine; 3,3',5,5'-tetramethylbenzidine, 2,2-bis(4-aminophenyl)hexafluoropropane, m-xylylenediamine, p-xylylenediamine, bis(4-amino-3-methylcyclohexyl)methane, and 1,2-bis(2-aminoethoxy)ethane. Y in formula (1) is a residue (divalent linking group) obtained by removing two amino groups from compound (A).

[0015] The compound (A) is preferably an aliphatic diamino compound having two or more carbon atoms, and specific examples thereof include 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, hexamethylenediamine, 1,8-diaminooctane, 1,10-diaminodecane, 1,12-diaminododecane, 4,4'-methylenebiscyclohexanediamine, 1,2-cyclohexanediamine, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, isophoronediamine, norbornenediamine, and dimer diamine. Y in formula (1) is preferably a residue (divalent linking group) obtained by removing two amino groups from the above-mentioned aliphatic diamino compound having two or more carbon atoms.

[0016] Compound (B) is a bismaleimide compound obtained by a condensation ring-closing reaction between a bis-3,5-dialkyl-4-aminophenylmethane compound and maleic acid, in which the four alkyl groups are each independently a methyl group, an ethyl group, an isopropyl group, or a tertiary butyl group. Specific examples of the compound (B) include 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, 3,3',5,5'-tetramethyl-4,4'-diphenylmethane bismaleimide, and 3,3',5,5'-tetraisopropyl-4,4'-diphenylmethane bismaleimide. R1 to R4 in formula (1) are alkyl groups contained in the above-mentioned compound (B), and are preferably methyl or ethyl groups.

[0017] Bismaleimide compounds, in which a hydrogen atom is located at the ortho position of the carbon atom on the benzene ring to which the maleimide group is bonded, are highly reactive with secondary amino groups, and therefore are prone to gelation during copolymerization due to the reaction between the ortho hydrogen atom and the amino group of compound (A). However, by using compound (B), in which all ortho positions are alkyl groups, gelation during copolymerization with compound (A) can be prevented.

[0018] The amounts of compound (A) and compound (B) used when synthesizing copolymer (C) are preferably 0.4 to 0.98 moles, more preferably 0.5 to 0.96 moles, of compound (A) per mole of compound (B). The reaction temperature during synthesis is usually 50 to 150°C, preferably 60 to 140°C, and the reaction time is usually 0.5 to 30 hours, preferably 1 to 20 hours. A reaction catalyst may be used. The reaction may be terminated when the molecular weight measured by GPC (gel permeation chromatography) no longer increases from a certain value. The solvent used in the reaction may be distilled off under heating and reduced pressure, or may be used as is in a resin composition containing the solvent.

[0019] A solvent is preferably used in the copolymerization reaction of compound (A) and compound (B), and examples of usable solvents include toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, propylene glycol monomethyl ether acetate, etc. The amount of solvent used is preferably 10 to 300% by mass, more preferably 20 to 200% by mass, based on the solid content of the raw materials used in the copolymerization reaction.

[0020] The number-average molecular weight of the copolymer (C) is usually 1,000 to 100,000, preferably 1,500 to 80,000, and in order to obtain a copolymer (C) having a number-average molecular weight within the above range, the raw material components may be charged in the above-mentioned ratio. Note that the molecular weight in this specification means a value calculated in terms of polystyrene based on the results of GPC measurement.

[0021] Next, the polymer compound of the present invention will be described. The polymer compound of the present invention can be obtained by reacting 5% or more but less than 100% of the secondary amino groups present in the copolymer (C) with isocyanate groups in a compound (D) represented by the following formula (3), and then acetylating the secondary amino groups remaining in the reaction product obtained above by reacting them with acetic anhydride. In addition, R5 in formula (3) has the same meaning as R5 in formula (2). That is, R5 in formula (2) is derived from a hydrogen atom or a methyl group contained in compound (D).

[0022] [ka]

[0023] Specific examples of the compound (D) include 2-isocyanatoethyl methacrylate (product name Karenz MOI, manufactured by Showa Denko KK), 2-isocyanatoethyl acrylate (product name Karenz AOI, manufactured by Showa Denko KK), and the like.

[0024] The amounts of copolymer (C) and compound (D) used in synthesizing the polymer compound of the present invention are preferably 0.05 to 0.9 mol, more preferably 0.1 to 0.8 mol, of compound (D) per equivalent of secondary amino groups in copolymer (C). The reaction temperature is preferably 10 to 90°C, and the reaction time is preferably 30 minutes to 5 hours.

[0025] The remaining secondary amino groups can be acetylated by adding acetic anhydride to the reaction product of the copolymer (C) and compound (D) obtained above. In a preferred embodiment of the method for synthesizing a polymer compound of the present invention, the copolymerization reaction of compound (A) and compound (B) is carried out in a solvent, compound (D) is added to the resulting solution of copolymer (C) to react with the copolymer, and acetic anhydride is further added to the resulting reaction solution to carry out acetylation. The amount of acetic anhydride used in synthesizing the polymer compound of the present invention may be equal to or greater than the number of moles of secondary amine remaining in the reaction product of copolymer (C) and compound (D). The reaction temperature is preferably 10 to 90°C, and the reaction time is preferably 30 minutes to 5 hours. After completion of the reaction, the acetic acid produced and excess acetic anhydride can be removed by washing with water.

[0026] The resin composition of the present invention contains the polymer compound of the present invention and a radical initiator. 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)hexyne-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.

[0027] Examples of preferred photoradical initiators include benzoin and its alkyl ethers such as benzoin, benzoin methyl ether, and benzoin ethyl ether; acetophenones such as acetophenone, 2,2-dimethoxy-2-phenylacetophenone, and 1,1-dichloroacetophenone; anthraquinones such as 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; benzophenones such as 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.

[0028] The content of the radical initiator in the resin composition of the present invention is usually 0.1 to 10 parts by mass, preferably 0.1 to 8 parts by mass, per 100 parts by mass of the polymer compound and the resin components such as the optional radical-reactive monomer described below.

[0029] The resin composition of the present invention may contain a radical-reactive monomer. The use of a radical-reactive monomer can improve the reactivity of the resin composition of the present invention and the heat resistance of the cured product. The radical-reactive monomer in the present invention refers to a compound having one or more radical-reactive functional groups in one molecule and having a number-average molecular weight of 500 or less (the lower limit of the number-average molecular weight is generally about 100). Specific examples of radical reactive monomers 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, and ethylene oxide adduct methacrylate of bisphenol A. acrylate, trimethylolpropane trimethacrylate, tricyclodecane dimethanol dimethacrylate, glycerin dimethacrylate, trimethylolpropane trimethacrylate, ethoxylated isocyanuric acid triacrylate, ε-caprolactone modified tris-(2-acryloxyethyl) isocyanurate, pentaerythritol triacrylate, ditrimethylolpropane tetraacrylate, ethoxylated pentaerythritol tetraacrylate, pentaerythritol tetraacrylate, dipentaerythritol thritol polyacrylate, dipentaerythritol hexaacrylate, triallyl isocyanurate, triallyl cyanurate, divinylbenzene, divinyl isophthalate, N-phenyl-maleimide, N-phenyl-methylmaleimide, N-phenyl-chloromaleimide, Np-chlorophenyl-maleimide, Np-methoxyphenyl-maleimide, Np-methylphenyl-maleimide, Np-nitrophenyl-maleimide, Np-phenoxyphenyl-maleimide, Np-phenylaminophenyl-maleimide, Np-phenoxycarbonylphenyl-maleimide, 1-maleimido-4-acetoxysuccinimide-benzene, 4-maleimido-4'-acetoxysuccinimide-diphenylmethane, 4-maleimido-4'-acetoxysuccinimide-diphenyl ether, 4-maleimido-4'-acetamido-diphenyl ether, 2-maleimido-6-acetamido-pyridine, 4-maleimido-4'-acetamido-diphenylmethane and Np-phenylcarbonylphenyl-maleimide, N-ethylmaleimide, N-2-maleimide.Examples include 6-xylylmaleimide, N-cyclohexylmaleimide, N-2,3-xylylmaleimide, xylylmaleimide, 2,6-xylenemaleimide, and 4,4'-bismaleimidediphenylmethane, but those having a maleimide group as a functional group are preferred. These radical reactive monomers may be used alone or in combination of two or more.

[0030] The resin composition of the present invention may be used in combination with a radical-reactive polymer. By using a radical-reactive polymer in combination, the adhesiveness of the resin composition of the present invention and the heat resistance of the cured product can be improved. In addition, the radical-reactive polymer in the present invention means a compound having one or more, preferably two or more, radical-reactive functional groups in one molecule and having a number average molecular weight of 500 or more. Specific examples of radical reactive polymers include styrene-butadiene copolymers, modified polyphenylene ether resins, imide-extended bismaleimides, and polymer compounds represented by the following formula (4): m in formula (4) is the average number of repeating units and represents a real number ranging from 1 to 20.

[0031] [ka]

[0032] The styrene-butadiene copolymer, which is a radical-reactive polymer, may be a random copolymer (commonly known as SBR) or a block copolymer. It may also be a block copolymer in which the butadiene-derived double bonds in the block copolymer are hydrogenated to form saturated hydrocarbons (commonly known as SEBS resin). The styrene to butadiene ratio in the polymer is typically 10:90 to 90:10, and the number average molecular weight is typically 1,000 to 100,000. Specific examples of SBR products include Ricon 100, Ricon 181, and Ricon 184 from Cray Valley Corporation, and specific examples of SEBS resin products include the Tuftec series from Asahi Kasei Corporation and the G Polymer series from Kraton.

[0033] The modified polyphenylene ether resin, which is a radical reactive polymer, is preferably a compound having methacryloyl groups, acryloyl groups, or vinyl groups at both molecular terminals and a number-average molecular weight of 1,000 to 10,000. Specific examples include a compound represented by the following formula (5) (product name: SA9000, manufactured by SABIC Japan, LLC) having methacryloyl groups at both terminals and a number-average molecular weight of about 1,700, and a compound represented by the following formula (4) (product name: OPE-2St 1200 or OPE-2St 2200, manufactured by Mitsubishi Gas Chemical Company, Inc.) having vinyl groups at both terminals and a number-average molecular weight of about 1,200 or 2,200.

[0034] [ka]

[0035] [ka]

[0036] The imide-extended bismaleimide resin, which is a radical-reactive polymer, can be obtained by a known method such as that described in Japanese Patent Publication No. 5328006. Specifically, the resin can be obtained by carrying out a dehydration condensation reaction of an aliphatic diamine and an aromatic or aliphatic tetracarboxylic dianhydride in an organic solvent using an acid catalyst in a molar ratio such that the aliphatic diamine is in excess, followed by dehydration condensation of amino groups present at the polymer terminals with maleic anhydride, and then removing the catalyst by washing with water.

[0037] Specific examples of aliphatic diamines include 1,10-diaminodecane; 1,12-diaminododecane; dimer diamine; 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-diaminomenthane; 1,8-diaminooctane; 1,9-diaminononane; 3,3'-diamino-N-methyldipropylamine; diaminomaleonitrile; 1,3-diaminopentane; and 9,10-diaminophenanthrene, with dimer diamine being particularly preferred.

[0038] 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)oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, diethylenetriaminepentaacetic dianhydride, ethylenediaminetetraacetic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4, 4'-Biphenyltetracarboxylic dianhydride, 4,4'-oxydiphthalic anhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 2,2'-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride, 4,4'-bisphenol A diphthalic anhydride, 5-(2,5-dioxytetrahydro)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, ethylene glycol bis(trimellitic anhydride), hydroquinone diphthalic anhydride, 1,2,3,4-cyclobutane Tetracarboxylic 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 anhydride, 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic dianhydride, and 3,5,6-tricarboxy-2-norbornane acetic dianhydride, with pyromellitic anhydride and 1,2,4,5-cyclohexane tetracarboxylic dianhydride being particularly preferred. A specific product name is BMI-3000 from Designer Molecules, Inc.

[0039] The resin composition of the present invention may contain an organic solvent. Specific examples of the organic solvent 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, of the resin composition.

[0040] The resin composition of the present invention may contain a polymerization inhibitor in order to improve storage stability. The polymerization inhibitor that can be used in combination is not particularly limited as long as it is a commonly known polymerization inhibitor, and examples thereof include quinones such as hydroquinone, methylhydroquinone, p-benzoquinone, chloranil, and trimethylquinone, aromatic diols, and di-t-butylhydroxytoluene.

[0041] The resin composition of the present invention can be blended with fillers and additives in amounts that do not impair the inherent performance, in order to impart desired performance depending on the application. The fillers may be fibrous or powdery, and examples of such fillers include silica, carbon black, alumina, talc, mica, glass beads, and glass hollow spheres.

[0042] The resin composition of the present invention can also contain flame-retardant compounds, additives, and the like. These compounds are not particularly limited as long as they are commonly used. Examples of flame-retardant compounds include bromine compounds such as 4,4-dibromobiphenyl, phosphate esters, melamine phosphate, phosphorus-containing epoxy resins, nitrogen compounds such as melamine and benzoguanamine, oxazine ring-containing compounds, and silicon-based compounds. Additives include ultraviolet absorbers, antioxidants, photopolymerization initiators, fluorescent brighteners, photosensitizers, dyes, pigments, thickeners, lubricants, antifoaming agents, dispersants, leveling agents, gloss agents, and the like, which can be used in appropriate combinations as desired.

[0043] The resin composition of the present invention can be used by coating or impregnating various substrates. For example, when a thermal radical initiator is used, it can be applied to a PET film to form an interlayer insulating layer for a multilayer printed circuit board, to a polyimide film to form a coverlay, or to a copper foil to form a resin-coated copper foil by coating and drying it. Furthermore, by impregnating glass cloth, glass paper, carbon fiber, various nonwoven fabrics, etc., it can be used as a printed wiring board or a CFRP prepreg. Furthermore, by using a photoradical initiator, it can also be used as a variety of resists.

[0044] The interlayer insulating layer, coverlay, resin-coated copper foil, prepreg, etc. of the present invention can be heated and pressure-molded using a hot press or the like to form a cured product. [Example]

[0045] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0046] Example 1 (Synthesis of polymer compound of the present invention) A flask equipped with a thermometer, condenser, nitrogen gas inlet, and stirrer was charged with 22.10 parts (0.05 mol) of 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide (product name: BMI-70, manufactured by K.I. Chemical Co., Ltd.), 20.18 parts (0.0375 mol) of dimer diamine (product name: Priamine 1074, manufactured by Croda), and 20 parts of toluene. The mixture was reacted at 100°C under a nitrogen atmosphere for 8 hours to obtain a toluene solution of copolymer 1 (copolymer (C), an intermediate raw material for the polymer compound of the present invention; Y in formula (7) represents the residue obtained by removing two amino groups from dimer diamine) represented by the following formula (7): The number-average molecular weight of this copolymer 1 was 2,700, and the weight-average molecular weight was 15,100. From the number-average molecular weight, the value of n in formula (7) was calculated to be 2.5. To a toluene solution of this copolymer, 1.16 parts (0.0075 mol) of Karenz MOI (Showa Denko K.K.) was added and the mixture was allowed to react at 60°C for 1 hour. Then, 6.12 parts (0.0675 mol) of acetic anhydride was added and the mixture was allowed to react at 60°C for another 1 hour. The reaction mixture was diluted with 100 parts of toluene, and then 50 parts of pure water was added. The mixture was stirred and washed with water to remove the by-product acetic acid. After repeated washing with water until the aqueous layer became neutral, the toluene solution was concentrated to obtain a 25% by mass toluene solution of the polymer compound of the present invention.

[0047] [ka]

[0048] Comparative Example 1 (Synthesis of Comparative Polymer Compound) A 25% by mass toluene solution of a comparative polymer compound was obtained in the same manner as in Example 1, except that the step of adding Karenz MOI and reacting at 60°C for 1 hour was omitted and the amount of acetic anhydride added was changed to 7.65 parts (0.075 mol).

[0049] Example 2 and Comparative Example 2 (Preparation of Resin Composition) To 10 parts of the polymer compound solution obtained in Example 1 and Comparative Example 1, 0.05 parts of dicumyl peroxide as a radical initiator was added and mixed uniformly to obtain a resin composition of the present invention and a comparative resin composition, respectively.

[0050] (Evaluation of dielectric properties, glass transition temperature and linear expansion coefficient (α1) of cured resin composition) Using an applicator, the resin compositions obtained in Example 2 and Comparative Example 2 were each applied to a thickness of 280 μm onto the mirror-like surface of 18 μm-thick copper foil, and then heated at 90°C for 10 minutes to dry the solvent. The resulting film-like adhesive on the copper foil was then heat-cured in a vacuum oven at 180°C for 1 hour, after which the copper foil was removed by immersion in an etching solution. Both the film-like adhesive of the present invention and the comparative film-like adhesive yielded cured products with a thickness of 70 μm that could be handled as films, and the dielectric properties of these cured products were evaluated. The dielectric properties were measured using a network analyzer 8719ET (Agilent Technologies) by cavity resonance to measure the dielectric constant and dielectric loss tangent at 10 GHz. Furthermore, the glass transition temperature and linear expansion coefficient (α1) of the cured film-like adhesive were determined using a TMA (thermomechanical analyzer). The results are shown in Table 1.

[0051] (Evaluation of adhesive strength and heat resistance of cured resin composition) The resin compositions obtained in Example 2 and Comparative Example 2 were applied to a 50 μm thickness on the matte side of a 12 μm-thick, low-roughness copper foil for high-frequency applications (CF-T4X-SV, manufactured by Fukuda Metal Foil & Powder Co., Ltd.) using an applicator. The solvent was then dried at 90°C for 10 minutes to obtain a copper foil bearing a film-like adhesive comprising the resin composition of the present invention. The matte side of the same copper foil was then placed on the adhesive side of the obtained copper foil and heated in a vacuum press at a pressure of 3 MPa for 1 hour to cure. The 90° peel strength (adhesion strength) between the copper foils was then measured using an Autograph AGX-50 (manufactured by Shimadzu Corporation). The laminated copper foil was cut into 3 cm squares and floated in a solder bath at 288°C. The time until abnormalities such as blistering or peeling occurred on the copper foil was measured. The results are shown in Table 1.

[0052] [Table 1]

[0053] Example 3 (Preparation of Resin Composition of the Present Invention) To 10 parts of the polymer compound solution of the present invention obtained in Example 1, 0.05 parts of dicumyl peroxide as a radical initiator and 0.5 parts of a butadiene-styrene copolymer, Licon 100 (manufactured by Cray Valley Chemical Industries, Ltd.), were added and mixed uniformly to obtain a resin composition of the present invention.

[0054] Example 4 (Preparation of Resin Composition of the Present Invention) To 10 parts of the polymer compound solution of the present invention obtained in Example 1, 0.05 parts of dicumyl peroxide as a radical initiator and 0.5 parts of modified polyphenylene ether resin SA-9000 (manufactured by Sabic LLC) were added and mixed uniformly to obtain a resin composition of the present invention.

[0055] Example 5 (Preparation of Resin Composition of the Present Invention) To 10 parts of the polymer compound solution of the present invention obtained in Example 1, 0.05 parts of dicumyl peroxide as a radical initiator and 0.5 parts of imide-extended bismaleimide resin BMI-3000 (manufactured by Designer Molecules, Inc.) were added and mixed uniformly to obtain a resin composition of the present invention.

[0056] (Evaluation of cured resin composition) The properties of the resin compositions obtained in Examples 3 to 5 were evaluated using the same methods as in the above "Evaluation of dielectric properties, glass transition temperature, and linear expansion coefficient (α1) of cured resin compositions" and "Evaluation of adhesive strength and heat resistance of cured resin compositions." The results are shown in Table 2.

[0057] [Table 2]

[0058] As described above, the polymer compound of the present invention can be cured in the presence of a radical initiator to form a flexible film, and the cured product exhibits excellent dielectric properties, adhesiveness, and heat resistance.

Claims

1. The following formula (1) 【Chemistry 1】 (In formula (1), R １ , R ２ , R ３ and R ４ Each X independently represents an acetyl group or a group represented by the following formula (2): 【Chemistry 2】 (In formula (2), R ５ represents a hydrogen atom or a methyl group. wherein at least one of the multiple X's is an acetyl group, and 5% or more of the multiple X's have a structure represented by formula (2). Y represents a residue obtained by removing two amino groups from dimer diamine. n is the average number of repeating units and is in the range of 1 to 100.

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

3. The resin composition according to claim 2, further comprising a radical-reactive monomer having a radical-reactive functional group.

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

5. A film-like adhesive comprising the resin composition according to any one of claims 2 to 4.

6. A cured product of the resin composition according to any one of claims 2 to 4 or the film-like adhesive according to claim 5.

Images