Curable compound, resin composition containing the compound, and cured product

Abstract

To provide a curable compound which can be thermally or photo-cured by a radical initiator, is alkali-soluble, and gives a cured product having a low dielectric constant, a low dielectric loss tangent, high adhesiveness, and a high glass transition temperature.SOLUTION: A compound represented by the following formula (1): (In Formula (1), each X independently represents a divalent residue obtained by removing a hydroxyl group from a diol. Each Y independently represents a residue of a divalent aliphatic group or aromatic group. R's each independently represent a hydrogen atom or a methyl group. N is an average value of the number of repeating units and is a real number of 0.1 to 20. ) SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a compound that can undergo a thermal or photo-curing reaction when used in combination with a radical initiator. [Background technology]

[0002] Epoxy resins, which have excellent adhesive properties, insulating properties, and heat resistance, have traditionally been widely used in electronic materials such as printed wiring boards. In the resist field, a typical development method involves curing specific areas using a photoinitiator, followed by removal of the uncured portions using an alkaline solution such as tetramethylammonium hydroxide (TMAH). Therefore, alkali-solubility is required for resist resins. Resins produced by adding acrylic acid to the epoxy groups of multifunctional epoxy resins and then half-esterifying the resulting alcoholic hydroxyl groups with acid anhydrides such as tetrahydrophthalic anhydride have been widely used. However, resins produced by half-esterifying acid anhydrides contain a large amount of highly polar carboxylic acids in the molecule, resulting in a high dielectric loss tangent, making them unsuitable for high-frequency applications. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-75274 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 discloses a compound obtained by reacting a tetracarboxylic dianhydride having a specific structure with a diol compound and a (meth)acrylate having one hydroxyl group in the molecule, as a novel alkali-soluble curable resin. However, these polymer compounds have low heat resistance, such as low glass transition temperature, of the cured product, and furthermore, the high proportion of carboxylic acid results in a high dielectric loss tangent, making them unsuitable for recent high-frequency applications that require a low dielectric loss tangent.

[0005] The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a curable compound that is soluble in an alkaline aqueous solution, and that has a low dielectric constant and dielectric dissipation factor when cured, and that has high heat resistance and high adhesive strength. [Means for solving the problem]

[0006] That is, the present invention relates to the following [1] to [5]. In this application, "(Numerical value 1) to (Numerical value 2)" indicates that the upper and lower limit values ​​are included. [1] A compound represented by the following formula (1):

[0007] [ka]

[0008] (In formula (1), each X independently represents a divalent residue obtained by removing a hydroxyl group from a diol. Each Y independently represents a residue of a divalent aliphatic group or aromatic group. Each R independently represents a hydrogen atom or a methyl group. n is the average number of repeating units and is a real number of 0.1 to 20.) [2] The compound according to the above item [1], wherein the diol is a dimer diol. [3] A resin composition comprising the compound according to any one of the preceding items [1] and [2] and a radical initiator. [4] The resin composition according to the above item [3], which contains a radical reactive monomer having one or more functional groups in one molecule. [5] A cured product of the resin composition according to any one of the preceding items [3] and [4]. [Effects of the Invention]

[0009] The compound according to the present invention and a composition containing the compound are soluble in an alkaline aqueous solution and can be cured by using a radical initiator in combination with the compound and applying heat or light energy. The cured product of the composition can provide a compound having excellent dielectric properties, heat resistance, and adhesiveness. DETAILED DESCRIPTION OF THE INVENTION

[0010] The compound of the present invention is represented by the following formula (1).

[0011] [ka]

[0012] In formula (1), X's each independently represent a divalent residue obtained by removing a hydroxyl group from a diol. Y's each independently represent a residue of a divalent aliphatic group or aromatic group. R's each independently represent a hydrogen atom or a methyl group. n is the average number of repeating units and is preferably a real number of 0.1 to 20, more preferably a real number of 0.5 to 10. A polymer compound having n repeating units is preferred.

[0013] The value of n in formula (1) can be determined by GPC (gel permeation chromatography) measurement.

[0014] The compound represented by formula (1) can be produced by any method, including the following: 1 mole of 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride is charged with less than 1 mole of diol and an addition reaction is carried out to obtain an intermediate. The carboxylic acid anhydride present at the terminal of the obtained intermediate is reacted with an equimolar amount of (meth)acrylate having one hydroxyl group per molecule to convert all the acid anhydrides to carboxylic acids and esters, thereby obtaining the polymer compound represented by formula (1).

[0015] Preferred diols include ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, 1,5-pentanediol, 1,9-nonanediol, 1,4-hexanedimethanol, polyethylene glycol, 1,16-hexadecanediol, 1,17-heptadecanediol, 1,18-octadecanediol, 1,20-eicosanediol, and dimer diols having 36 carbon atoms. Dimer diols are particularly preferred from the viewpoint of improving the dielectric properties of the compound of the present invention. Dimer diols include those that retain the double bonds derived from the unsaturated fatty acid raw material and those that are hydrogenated. However, hydrogenated dimer diols are preferred from the viewpoint of preventing deterioration of the dielectric properties due to oxidation of the double bonds.

[0016] The dimer diol is a compound in which two carboxy groups of a dimer acid, which is a dimer of an unsaturated fatty acid such as oleic acid, are converted to primary hydroxyl groups. Non-limiting general formulas of dimer diols are shown below (in each formula, m+n=6 to 17, and p+q=8 to 19, and the dashed lines represent carbon-carbon single or double bonds). Dimer diols are usually a mixture of compounds represented by the following non-limiting general formula:

[0017] [ka]

[0018] Preferred (meth)acrylates having one hydroxyl group per molecule include 2-hydroxymethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, hydroquinone mono(meth)acrylate, cyclohexane mono(meth)acrylate, etc. In the formula (1), Y is a residue obtained by removing the hydroxyl group and the (meth)acrylate group from a (meth)acrylate having one hydroxyl group per molecule.

[0019] The intermediate of the compound of the present invention is represented by the following formula (2) and can be obtained by charging 1 mole of 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride with less than 1 mole of a diol compound and carrying out a half-esterification reaction.

[0020] [ka]

[0021] In formula (2), X and n have the same meanings as in formula (1).

[0022] Regarding the amount of raw materials used in the above reaction, the amount of the diol compound used is preferably 0.4 to 0.95 moles per mole of 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride, and more preferably 0.5 to 0.9 moles. A solvent is preferably used during the reaction. Usable solvents include toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, and γ-butyrolactone. The amount of solvent used is preferably 0 to 300 mass% based on the solid content, and more preferably 20 to 200 mass%. A catalyst may also be used to expedite the reaction. Examples of catalysts that can be used include pyridine and dimethylaminopyridine, as well as quaternary ammonium salts such as tetramethylammonium chloride, tetramethylammonium bromide, tetraethylammonium chloride, tetraethylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium bromide, 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 0.001 to 1%, and more preferably 0.005 to 0.5%, of the total mass of the reaction substrates.

[0023] Regarding the ratio of 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride to diol compound, the higher the ratio of diol compound, the higher the average molecular weight of the polymer intermediate, and the lower the ratio, the lower the average molecular weight, but both terminal residues of the intermediate will always be acid anhydrides. 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 reaction can be terminated when the molecular weight no longer increases from a certain value as determined by GPC (gel permeation chromatography).

[0024] Next, a (meth)acrylate having one hydroxyl group per molecule is added to the intermediate, and an addition reaction with the acid anhydride group present in the intermediate can be carried out to obtain the compound of the present invention. The amount of (meth)acrylate having one hydroxyl group per molecule used is preferably equimolar to the acid anhydride present in the system, i.e., twice the difference in moles between 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride and the diol compound used in the polymerization reaction, which is the synthesis step of the intermediate. The compound of the present invention can be obtained by adding a (meth)acrylate having one hydroxyl group per molecule to a reaction solution of the intermediate described above and stirring to allow the reaction to proceed. The reaction temperature is preferably 50 to 120°C, and the reaction time is preferably 1 to 20 hours.

[0025] The resin composition of the present invention contains the compound of the present invention and a radical initiator. As the radical initiator, a thermal radical initiator or a photoradical initiator can be used. 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.

[0026] 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 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; 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-one; acylphosphine oxides and xanthones; oxime esters such as 1,2-octanedione, 1-[4-(phenylthio)phenyl]-, 2-(o-benzoyloxime), and ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(o-acetyloxime).

[0027] 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 total of the resin components such as the compound and the optional radical reactive monomer described below.

[0028] The resin composition of the present invention may contain a radical reactive monomer. By using a radical reactive monomer in combination, the reactivity of the resin composition of the present invention and the heat resistance of the cured product can be improved. The radical reactive monomer is preferably one having one or more functional groups, and specific examples thereof 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, ethylene oxide adduct methacrylate of bisphenol A, 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 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- Examples of suitable maleimide compounds include diphenyl ether, 4-maleimide-4'-acetamido-diphenyl ether, 2-maleimide-6-acetamido-pyridine, 4-maleimide-4'-acetamido-diphenylmethane, Np-phenylcarbonylphenyl-maleimide, N-ethylmaleimide, N-2,6-xylylmaleimide, N-cyclohexylmaleimide, N-2,3-xylylmaleimide, xylylmaleimide, 2,6-xylenemaleimide, and 4,4'-bismaleimidediphenylmethane. These radical reactive monomers may be used alone or in combination of two or more.

[0029] 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. The radical-reactive polymer is preferably one having two or more functional groups, and specific examples thereof include a copolymer of styrene and butadiene, a modified polyphenylene ether resin, and an imide-extended bismaleimide.

[0030] The styrene-butadiene copolymer 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 ratio of styrene to butadiene in the polymer is typically 10:90 to 90:10. 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, while specific examples of SEBS resin products include the Tuftec series from Asahi Kasei Corporation and the G Polymer series from Kraton.

[0031] Preferred examples of modified polyphenylene ether resins include those having methacryloyl groups, acryloyl groups, or vinyl groups at both molecular terminals and having a number-average molecular weight of 1000 to 10000. Specific examples include a compound represented by the following formula (6) (product name: SA9000, manufactured by SABIC Japan LLC) having methacryloyl groups at both terminals and a number-average molecular weight of approximately 1700, and a compound represented by the following formula (7) (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 approximately 1200 or 2200.

[0032] [ka]

[0033] [ka]

[0034] The imide-extended bismaleimide resin used in the present invention 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.

[0035] 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.

[0036] 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-cyclobutanediol tetracarboxylic dianhydride (CBDA), 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic 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.

[0037] In addition, since the compound of the present invention is alkali-soluble, it can be used in combination with a conventional alkali-soluble curable resin. Specific examples of alkali-soluble curable resins include those obtained by addition reaction of acrylic acid with the epoxy groups of a polyfunctional epoxy resin, and then reacting the resulting alcoholic hydroxyl groups with a polybasic acid anhydride to form half esters.

[0038] Examples of polyfunctional epoxy resins include bisphenol A epoxy resins, bisphenol F epoxy resins, phenol novolac epoxy resins, cresol novolac epoxy resins, aralkylphenol novolac epoxy resins, biphenyl novolac epoxy resins, triphenylmethane epoxy resins, etc. Examples of the 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 chlorendic anhydride, and polybasic acid anhydrides such as trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, and biphenyltetracarboxylic anhydride.

[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 applied to or impregnated into various substrates. For example, when a thermal radical initiator is used, it can be applied to PET film to form an interlayer insulating layer for multilayer printed circuit boards, to polyimide film to form a coverlay, or to copper foil to form resin-coated copper foil by coating and drying. It can also be impregnated into glass cloth, glass paper, carbon fiber, various nonwoven fabrics, and the like to form printed wiring boards and CFRP prepregs. Furthermore, by using a photoradical initiator, it is possible to develop specific patterns by curing only the areas irradiated with light of a specific wavelength and washing the remaining areas with an alkaline aqueous solution. This allows the composition to be used as a variety of resists, such as rewiring layers for semiconductors and solder resists for printed circuit boards.

[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. Unless otherwise specified, parts are parts by mass. However, the present invention is not limited to these examples.

[0046] [Example 1 (Synthesis of Compounds of the Present Invention)] A flask equipped with a thermometer, condenser, nitrogen gas inlet, and stirrer was charged with 20.18 parts of hydrogenated dimer diol (product name Pripol 2033, manufactured by Cargill), 26.0 parts of 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride, 50 parts of propylene glycol monomethyl ether acetate (PGMEA), and 0.05 parts of pyridine. The mixture was reacted at 130°C for 3 hours to obtain a PGMEA solution of intermediate 1, containing a compound represented by formula (5). Because dimer diol is a mixture, it may also contain compounds with different structures derived from dimer diol. The value of n calculated from the number average molecular weight of 2900 measured by GPC was 2.2.

[0047] [ka]

[0048] The temperature of the solution of Intermediate 1 was lowered to 110°C, and 3.25 parts of 2-hydroxyethyl methacrylate was added while bubbling air into the system. The reaction was continued at 110°C for 10 hours. The temperature of the system was then lowered to room temperature, and 100 parts of methanol was added. After stirring, the mixture was allowed to stand to precipitate a polymer. The upper methanol layer was decanted to remove pyridine and traces of unreacted low-molecular-weight compounds. An additional 50 parts of PGMEA was added to the lower PGMAE layer, and the methanol dissolved in the system was removed by evaporation. The amount of PGMEA was adjusted to obtain 127 parts of a 35% PGMEA solution of the compound of the present invention, including the compound represented by formula (6): Because dimer diol is a mixture, it may contain compounds with different structures derived from dimer diol. The acid value of this compound was measured to be 114 mg KOH / g.

[0049] [ka]

[0050] [Comparative Example 1 (Synthesis of a comparative compound)] The same procedure as in Example 1 was carried out, except that 10.9 parts of pyromellitic anhydride was used instead of 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride, to obtain a PGMEA solution of intermediate 2 containing a compound represented by formula (7). Because dimer diol is a mixture, it may also contain compounds with different structures derived from dimer diol. The value of n calculated from the number average molecular weight of 2000 measured by GPC was 2.4.

[0051] [ka]

[0052] The temperature of the solution of intermediate 2 was lowered to 110°C, and 3.25 parts of 2-hydroxyethylene methacrylate was added while bubbling air into the system. The reaction was continued at 110°C for 10 hours. The temperature of the system was then lowered to room temperature, and 100 parts of methanol was added. After stirring, the mixture was allowed to stand to precipitate the polymer. The upper methanol layer was decanted to remove pyridine and traces of unreacted low-molecular-weight compounds. An additional 50 parts of PGMEA was added to the lower PGMAE layer, and the methanol dissolved in the system was removed by evaporation. The amount of PGMEA was adjusted to obtain 87 parts of a 35% PGMEA solution of a comparative compound containing a compound represented by formula (8): Because dimer diol is a mixture, it may contain compounds with different structures derived from dimer diol. The acid value of this compound was measured to be 167 mgKOH / g.

[0053] [ka]

[0054] [Example 2, Comparative Example 2] (Alkali solubility evaluation) 0.16 parts of each of the resin solutions obtained in Example 1 and Comparative Example 1 were placed in a 20 ml sample tube, left at 130°C for 30 minutes to completely evaporate the solvent, and then 10 ml of a 2.38% aqueous solution of TMAH (tetramethylammonium hydroxide) was added and the time until complete dissolution was measured.

[0055] [Table 1]

[0056] [Example 3, Comparative Example 3 (Preparation of Resin Composition)] To 10 parts of the resin solution obtained in Example 1 and Comparative Example 1, 0.08 parts of dicumyl peroxide as a radical initiator was added and mixed uniformly to obtain Resin Composition 1 of the present invention and Resin Composition 2 for comparison.

[0057] (Evaluation of dielectric properties, heat resistance, and adhesive properties of cured resin compositions) Resin compositions 1 and 2 obtained in Example 3 and Comparative Example 3 were applied to the mirror surface of 18 μm-thick copper foil to a thickness of 140 μm using an applicator. The coating was then heated at 90°C for 10 minutes to dry off the solvent, yielding copper foil bearing a film-like adhesive made from the resin composition. The film-like adhesive on the copper foil obtained above was then cured by heating at 180°C for 1 hour in a vacuum oven, and then immersed in an etching solution to remove the copper foil, yielding a 70 μm-thick cured film-like adhesive that could be handled as a film. The dielectric constant and dielectric loss tangent of the cured product at 10 GHz were measured by cavity resonance using a network analyzer 8719ET (Agilent Technologies). The glass transition temperature of the same sample was also measured using a thermomechanical analyzer (TMA). The results are shown in Table 2.

[0058] Resin compositions 1 and 2 were applied to 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 to a thickness of 50 μm. The coating was then heated at 90°C for 10 minutes to dry off the solvent, yielding a copper foil bearing a film-like adhesive made from the resin composition. The matte side of the same copper foil was then placed on top of the adhesive side of the resin-coated copper foil obtained above, and the resulting foil was heated and cured in a vacuum press at a pressure of 3 MPa for 1 hour. 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.

[0059] [Table 2]

[0060] As described above, the compounds of the present invention exhibit good solubility in alkaline aqueous solutions, and the compositions thereof exhibit excellent dielectric properties, heat resistance, and adhesive properties when cured using a radical initiator.

Claims

1. A compound represented by the following formula (1): 【Chemistry 1】 (In formula (1), each X independently represents a divalent residue obtained by removing a hydroxyl group from a diol. Each Y independently represents a residue of a divalent aliphatic group or aromatic group. Each R independently represents a hydrogen atom or a methyl group. n is the average number of repeating units and is a real number from 0.1 to 20.)

2. The compound of claim 1 , wherein the diol is a dimer diol.

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

4. The resin composition according to the above item [3], which contains a radical reactive monomer having one or more functional groups in one molecule.

5. A cured product of the resin composition described in the preceding item [3].

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