TWI884967B - Resin composition and cured product thereof, impregnated substrate, prepreg, laminate, printed wiring board and semiconductor package - Google Patents

Abstract

The subject of the present invention is to provide a resin composition that exerts the stress relief effect brought about by low elastic modulus while maintaining the heat resistance of the resin, and at the same time has better adhesion to copper foil. The resin composition of the present invention comprises a resin (A) having a free radical polymerizable group, a thermoplastic resin (B), and a free radical polymerization initiator (C), wherein the resin (A) having a free radical polymerizable group comprises a vinyl ester resin, an unsaturated polyester resin or a polyphenylene ether resin having a free radical polymerizable group, and the thermoplastic resin (B) comprises at least one selected from the group consisting of polyester polyols and polyurethane polyols, and the cured product of the resin composition forms a phase separation structure.

Description

Resin composition and cured product thereof, impregnated substrate, prepreg, laminate, printed wiring board and semiconductor package

The present invention relates to a resin composition, a prepreg, a laminate, a multilayer printed wiring board and a semiconductor package.

Radical polymerizable resins have a good balance of mechanical strength, chemical durability, electrical properties, etc., and are widely used in construction and industrial fields such as machinery, automobiles, ships, and semiconductors. As such a radical polymerizable resin composition, for example, a laminate has been proposed, which is obtained by impregnating a fiber-reinforced layer with a thermosetting resin composition containing a radical polymerizable resin, a thermoplastic resin, a radical polymerizable monomer, and an inorganic filler in a specific ratio and hardening the fiber-reinforced layer (see Patent Document 1).

[Prior art literature] [Patent Literature]

[Patent Document 1] International Publication No. 2001/072879

However, the previously known free radical polymerizable resin composition has insufficient adhesion to the copper foil with low surface roughness used in the copper-clad laminate. In addition, there is a problem of residual stress caused by the difference in linear expansion coefficient between the copper foil and the resin part, which sometimes causes problems in the warping of the laminate, the reduction of the adhesion reliability at the copper foil/resin interface, and the generation of cracks. The present invention is completed in view of the above situation, and its subject is to provide a resin composition that exerts the stress relief effect brought about by the low elastic modulus while maintaining the heat resistance of the resin, and at the same time has better adhesion to the copper foil.

The resin composition of the present invention comprises a resin (A) having a free radical polymerizable group, a thermoplastic resin (B), and a free radical polymerization initiator (C), wherein the resin (A) having a free radical polymerizable group comprises a vinyl ester resin, an unsaturated polyester resin, or a polyphenylene ether resin having a free radical polymerizable group, and the thermoplastic resin (B) comprises at least one selected from the group consisting of polyester polyols and polyurethane polyols, and the cured product of the resin composition forms a phase separation structure.

By using the resin composition of the present invention, a resin composition can be provided that can exert the stress relief effect brought about by the low elastic modulus while maintaining the heat resistance of the resin and at the same time has better adhesion to the copper foil.

The resin composition of the present invention comprises a resin (A) having a free radical polymerizable group, a thermoplastic resin (B), and a free radical polymerization initiator (C).

The resin (A) having a free radical polymerizable group can be any resin having a free radical polymerizable group (a group having an ethylene unsaturated bond) in the molecule, and can include one or more resins. Examples of the resin (A) having a free radical polymerizable group include vinyl ester resins, unsaturated polyester resins, and polyphenylene ether resins having a free radical polymerizable group.

The vinyl ester resin is preferably a reaction product of an epoxy resin and an unsaturated carboxylic acid.

As the epoxy resin, an epoxy resin having two or more epoxy groups in one molecule is preferred. As the epoxy resin, one or more types can be used, for example, bisphenol type epoxy resin, phenylene ether type epoxy resin, naphthylene ether type epoxy resin, biphenyl type epoxy resin, triphenylmethane type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, diphenol type epoxy resin, Phenol novolac type epoxy resin, naphthol novolac type epoxy resin, naphthol-phenol co-phenol novolac type epoxy resin, naphthol-cresol co-phenol novolac type epoxy resin, phenol aralkyl type epoxy resin, naphthol aralkyl type epoxy resin, dicyclopentadiene-phenol addition reaction type epoxy resin, etc.

The unsaturated carboxylic acid is a compound having one carboxyl group and one or more ethylenic unsaturated groups in one molecule, and examples thereof include: (meth)acrylic acid, crotonic acid, o-vinylbenzoic acid, m-vinylbenzoic acid, p-vinylbenzoic acid and other unsaturated monocarboxylic acids, etc.

As the vinyl ester resin, a (meth)acrylic acid adduct of an epoxy resin is preferred.

The number average molecular weight of the vinyl ester resin is preferably greater than 500, more preferably greater than 1,000, and preferably less than 5,000, more preferably less than 3,000.

In the present invention, the number average molecular weight of the vinyl ester resin is a value measured by gel permeation chromatography and converted to polystyrene as a standard sample.

The unsaturated polyester resin is preferably a dehydration condensation reaction product of an unsaturated dicarboxylic acid or its anhydride and a diol.

Examples of the unsaturated dicarboxylic acid include maleic acid, fumaric acid, citric acid, mesaconic acid, itaconic acid, 3-vinylphthalic acid, 4-vinylphthalic acid, 3,4,5,6-tetrahydrophthalic acid, 1,2,3,6-tetrahydrophthalic acid, dimethyltetrahydrophthalic acid, and 1,4-cyclohexene dicarboxylic acid.

The diols mentioned above can be compounds having two hydroxyl groups in one molecule, and examples thereof include: ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, cyclohexanediol and other alkane diols; oxyalkylene glycols such as dioxyethylene glycol, dipropylene glycol, triethylene glycol; alkane diol adducts of bisphenol compounds (such as bisphenol A, etc.), etc.

The unsaturated polyester resin is preferably a dehydration condensation reaction product of unsaturated dicarboxylic acids such as maleic acid, fumaric acid, liraconic acid, mesaconic acid, etc. and diols.

The number average molecular weight of the unsaturated polyester resin is preferably 500 or more, more preferably 1,000 or more, and preferably 5,000 or less, more preferably 3,000 or less.

In the present invention, the number average molecular weight of the unsaturated polyester resin is a value measured by gel permeation chromatography and converted to polystyrene as a standard sample.

The polyphenylene ether resin has at least one free radical polymerizable group. Examples of the free radical polymerizable group include vinyl and allyl groups. The polyphenylene ether resin is preferably represented by the following formula (1). In the polyphenylene ether resin, each structural unit may contain one or more than two structural units, and the repetition order of each structural unit is not particularly limited.

[In formula (1), Ar ¹ , Ar ² , and Ar ³ each independently represent an aromatic hydrocarbon group which may have a substituent, and a radical polymerizable group is added to at least one of Ar ¹ , Ar ² , and Ar ^{3. L 1} and L ² each independently represent a single bond or a hydrocarbon group. n represents an integer greater than 1, and when n is greater than 2, the structural units in parentheses to which n is added may be the same or different.]

Examples of the aromatic hydrocarbon group represented by Ar ¹ and Ar ² include aromatic hydrocarbon groups having 6 to 20 carbon atoms such as phenyl and naphthyl.

Examples of the aromatic hydrocarbon group represented by Ar ³ include aromatic hydrocarbon groups having 6 to 20 carbon atoms, such as phenylene group and biphenylene group.

The substituents that the aromatic hydrocarbon group represented by Ar ³ may have include: alkyl groups having 1 to 9 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, t-butyl, n-pentyl, n-hexyl, n-heptyl, 1-methylpentyl, 1-ethylpentyl, etc.; cycloalkyl groups having 1 to 9 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc.; alkenyl groups having 2 to 9 carbon atoms such as vinyl, allyl, isopropenyl, butenyl, etc.; alkynyl groups having 2 to 9 carbon atoms such as propynyl, butynyl, etc.; aromatic hydrocarbon groups having 1 to 9 carbon atoms such as phenyl, etc.; and combinations of one or more of these groups. a halogen atom such as a fluorine atom or a chlorine atom; a cyano group; a hydroxyl group; an alkenyl group such as a vinyl group or an allyl group having 2 to 6 carbon atoms; a halogenated alkyl group such as a trifluoromethyl group having 1 to 6 carbon atoms; a substituted amino group such as a dimethylamino group; an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group, or a butoxy group having 1 to 6 carbon atoms; an alkoxy group such as a methoxymethoxy group or a methoxyethoxy group having 1 to 6 carbon atoms substituted by an alkoxy group having 1 to 6 carbon atoms; a cycloalkyl group such as a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, or a cycloheptyl group having 3 to 8 carbon atoms; a nitro group; an aryl group such as a phenyl group, a 4-chlorophenyl group, or a naphthyl group; and the like.

Examples of the alkyl group represented by L ¹ and L ² include alkanediyl groups having 1 to 20 carbon atoms such as methylene, ethylene, propanediyl, and hexanediyl; cyclopropanediyl groups; cycloalkanediyl groups having 3 to 20 carbon atoms such as cyclohexanediyl; vinylene groups; alkenediyl groups having 2 to 20 carbon atoms such as isopropanediyl; alkynyldiyl groups having 2 to 20 carbon atoms such as propynyl; and aromatic alkyl groups having 6 to 20 carbon atoms such as phenylene and 2,6-naphthyl. In the present invention, the aromatic alkyl group includes a alkyl group containing an aromatic ring.

In the polyphenylene ether resin, a radical polymerizable group is preferably added to at least one of Ar ¹ and Ar ² .

The number average molecular weight of the polyphenylene ether resin is preferably greater than 500, more preferably greater than 1,000, and preferably less than 5,000, more preferably less than 3,000.

In the present invention, the number average molecular weight of the polyphenylene ether resin is a value measured by gel permeation chromatography and converted to polystyrene as a standard sample.

In the resin (A) having a free radical polymerizable group, the total content of the vinyl ester resin, the unsaturated polyester resin and the polyphenylene ether resin having a free radical polymerizable group is preferably 80% by mass or more, more preferably 90% by mass or more, and further preferably 95% by mass or more, and the upper limit is 100% by mass.

The thermoplastic resin (B) includes at least one selected from the group consisting of polyester polyol (B1) and polyurethane polyol (B2).

The polyester polyol (B1) is a polymer having an ester bond in the molecular chain and having two or more hydroxyl groups in one molecule. The number of hydroxyl groups in the polyester polyol is two or more in each molecule, and preferably five or less, and more preferably four or less.

As the polyester polyol (B1), for example, there can be listed: polyester polyols obtained by esterification reaction of low molecular weight polyols (for example, polyols with a molecular weight of 50 or more and 300 or less) with polycarboxylic acids; polyester polyols obtained by ring-opening polymerization of cyclic ester compounds such as ε-caprolactone; polyester polyols obtained by reacting (addition) one or more selected from the group consisting of polyether polyols, polyester polyols, and polycarbonate polyols and/or low molecular weight polyols used in the production of the polyester polyols as initiators with lactone compounds; copolyester polyols thereof, etc.

As the low molecular weight polyol used in the production of the polyester polyol (B1), a polyol with a molecular weight of 50 or more and 300 or less can be used, for example: ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, 1,3-butanediol, trihydroxymethylpropane, glycerol and other aliphatic polyols (diols or trifunctional or higher polyols) with 2 or more and 6 or less carbon atoms; 1,4-cyclohexanediol, cyclohexanedimethanol and other polyols containing alicyclic structures; bisphenol compounds such as bisphenol A and bisphenol F and their oxirane adducts and other polyols containing aromatic structures, etc.

As polycarboxylic acids used in the production of the polyester polyol (B1), there can be listed: aliphatic polycarboxylic acids such as succinic acid, adipic acid, sebacic acid, and dodecanedicarboxylic acid; aromatic polycarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, and naphthalene dicarboxylic acid; and anhydride or ester-forming derivatives of the aliphatic polycarboxylic acids and aromatic polycarboxylic acids, etc.

As the lactone compound, one or more can be used, for example: δ-valerolactone, β-methyl-δ-valerolactone, ε-caprolactone, α-methyl-ε-caprolactone, β-methyl-ε-caprolactone, γ-methyl-ε-caprolactone, β-dimethyl-ε-caprolactone, δ-dimethyl-ε-caprolactone, 3,3,5-trimethyl-ε-caprolactone, enantholactone (7-heptanolide), dodecanolactone (12-dodecanolide), etc. can be used.

The addition rate of the lactone compound is preferably 5% by mass or more, more preferably 10% by mass or more, and preferably 200% by mass or less, more preferably 100% by mass or less relative to 100% by mass of the total of one or more selected from the group consisting of the polyether polyol, polyester polyol, polycarbonate polyol and/or the low molecular weight polyol.

The number average molecular weight of the polyester polyol (B1) is preferably 600 or more, more preferably 1000 or more, and further preferably 1500 or more, and is preferably 20,000 or less, more preferably 15,000 or less, and further preferably 10,000 or less.

The number average molecular weight of the polyester polyol (B1) can be calculated based on the hydroxyl value. The hydroxyl value can be measured according to Japanese Industrial Standards (JIS) K 1557-1: 2007.

The polyurethane polyol (B2) is a polymer having at least a urethane bond in the molecular chain and having two or more hydroxyl groups in one molecule. The number of hydroxyl groups in the polyester polyol is two or more in each molecule, and preferably five or less, and more preferably four or less.

The polyurethane polyol (B2) is preferably a reaction product of a polyol compound (a) and a polyisocyanate compound (b).

As the polyol compound (a), one or more kinds can be used, preferably including polymer polyols. As the polymer polyols, polyether polyols, polyester polyols, polycarbonate polyols, etc. can be listed, preferably including at least one selected from the group consisting of polyether polyols, polyester polyols and polycarbonate polyols, and preferably including at least polyester polyols.

As the polyether polyol, preferably a polyoxyalkylene polyol can be listed, for example, one or more compounds having two or more active hydrogen atoms are used as initiators to carry out ring-opening polymerization of cyclic ethers such as alkylene oxide, etc.

The number of carbon atoms in the cyclic ether is preferably 2 to 10, more preferably 2 to 6, and further preferably 2 to 4. The hydrogen atoms contained in the cyclic ether may be replaced by halogen atoms. As the cyclic ether, one or more types may be used, for example: ethylene oxide, propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, alkylated tetrahydrofuran, etc.

As the initiator, one or more than one can be used, for example: compounds with two active hydrogen atoms such as ethylene glycol, diethylene glycol, propylene glycol, trimethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, water, etc.; compounds with three or more active hydrogen atoms such as glycerol, diglycerol, trihydroxymethylethane, trihydroxymethylpropane, hexanetriol, monoethanolamine, diethanolamine, triethanolamine, ethylenediamine, pentaerythritol, sugars, etc., etc.

As the polyester polyol, the same compound as the compound described as the polyester polyol (B1) can be used.

Examples of the polycarbonate polyol include: reactants of carbonate and polyol; reactants of phosgene and bisphenol A, etc.

Examples of the carbonate include methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclocarbonate, diphenyl carbonate, etc.

Examples of polyols that can react with the carbonate include: polyols exemplified as the low molecular weight polyols; high molecular weight polyols (weight average molecular weight of 500 or more and 5,000 or less) such as polyether polyols (polyethylene glycol, polypropylene glycol, etc.) and polyester polyols (polyhexamethylene adipate, etc.).

The functional number of the polymer polyol is preferably greater than 2 and less than 5.

The number average molecular weight of the polymer polyol is preferably 300 or more, more preferably 500 or more, and further preferably 700 or more, and is preferably 10,000 or less, more preferably 7,000 or less, and further preferably 5,000 or less.

The number average molecular weight of the polymer polyol can be calculated based on the hydroxyl value. The hydroxyl value can be measured according to JIS K 1557-1:2007.

As the polyisocyanate compound (b), one or more kinds can be used, for example: polyisocyanates with alicyclic structures such as cyclohexane diisocyanate, dicyclohexylmethane diisocyanate, and isophorone diisocyanate; aromatic polyisocyanates such as 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate, crude diphenylmethane diisocyanate, phenylene diisocyanate, toluene diisocyanate, and naphthalene diisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate, lysine diisocyanate, xylene diisocyanate, and tetramethylxylene diisocyanate.

The number of isocyanate groups contained in each molecule of the polyisocyanate compound (b) is 2 or more, preferably 5 or less, and more preferably 3 or less.

The equivalent ratio (NCO/OH) of the isocyanate group contained in the polyisocyanate compound (b) to the hydroxyl group contained in the polyol compound (a1) is preferably 0.1 or more, more preferably 0.2 or more, and preferably 0.9 or less, more preferably 0.8 or less, and particularly preferably 0.7 or less.

The hydroxyl value of the polyurethane polyol (B2) is preferably 11 mgKOH/g or more, more preferably 16 mgKOH/g or more, and further preferably 23 mgKOH/g or more, and preferably 225 mgKOH/g or less, more preferably 150 mgKOH/g or less, and further preferably 112 mgKOH/g or less.

The number average molecular weight of the polyurethane polyol (B2) is 500 or more, preferably 1000 or more, more preferably 1500 or more, particularly preferably 2000 or more, and preferably 10000 or less, more preferably 7000 or less, and even more preferably 5000 or less.

The number average molecular weight of the polyurethane polyol (B2) can be calculated based on the hydroxyl value. The hydroxyl value can be measured according to JIS K 1557-1:2007.

The solubility parameter of the polyester polyol (B1) and the polyurethane polyol (B2) is 9 (cal/cm ³ ) ^0.5 or more, preferably 9.1 (cal/cm 3 ) ^0.5 or more, more preferably 9.4 (cal/cm ³ ) ^0.5 or more, and further preferably 9.9 (cal/ ^{cm 3 ) 0.5} or more, and preferably 13 (cal/cm ³ ) ^0.5 or less, more preferably 11 (cal/cm ³ ) ^0.5 or less, and further preferably 10.5 (cal/cm ³ ) ^0.5 or less. If the solubility parameters of the polyester polyol (B1) and the polyurethane polyol (B2) are within the above range, phase separation is easily induced in the obtained cured product.

The solubility parameters of the polyester polyol (B1) and the polyurethane polyol (B2) can be calculated based on the method of Fedors (Polymer Engineering and Science, 1974, vol. 14, No. 2) to calculate the solubility parameters of the units derived from each compound used as the raw materials of the polyester polyol (B1) and the polyurethane polyol (B2), and based on the mass-based ratio of the units derived from each compound, it can be obtained as a weighted average.

In the thermoplastic resin (B), the total content of the polyester polyol (B1) and the polyurethane polyol (B2) is preferably 80% by mass or more, more preferably 90% by mass or more, further preferably 95% by mass or more, and preferably 100% by mass or less.

The glass transition temperature of the thermoplastic resin (B) is preferably above -100°C, more preferably above -80°C, further preferably above -70°C, and preferably below 50°C, more preferably below 40°C, further preferably below 30°C. In addition, when the thermoplastic resin (B) contains two or more resins, the weighted average of the glass transition temperatures of the resins is preferably above -100°C, more preferably above -80°C, further preferably above -70°C, and preferably below -50°C, more preferably below -40°C, further preferably below -30°C. Furthermore, when the thermoplastic resin (B) contains two or more resins, it is preferred that the glass transition temperatures of the two or more resins are within the above range.

The number average molecular weight of the thermoplastic resin (B) is preferably 500 or more, more preferably 1,000 or more, and further preferably 1,500 or more, and is preferably 30,000 or less, more preferably 20,000 or less, and further preferably 15,000 or less. When the thermoplastic resin (B) contains two or more resins, the weighted average of the number average molecular weights of the respective resins is preferably 500 or more, more preferably 1,000 or more, and further preferably 1,500 or more, and is preferably 30,000 or less, more preferably 20,000 or less, and further preferably 15,000 or less. In addition, when the thermoplastic resin (B) contains two or more resins, it is preferred that the number average molecular weight of each of the two or more resins is within the above range.

The solubility parameter of the thermoplastic resin (B) is preferably 9.0 (cal/cm ³ ) ^0.5 or more, more preferably 9.7 (cal/cm ³ ) ^0.5 or more, further preferably 9.5 (cal/cm ³ ) ^0.5 or more, and preferably 10.5 (cal/cm ³ ) ^0.5 or less, more preferably 10.4 (cal/cm ³ ) ^0.5 or less, further preferably 10.2 (cal/cm ³ ) ^0.5 or less.

The solubility parameter of the thermoplastic resin (B) can be calculated based on the method of Fedors (Polymer Engineering and Science, 1974, vol. 14, No. 2) and the solubility parameter and mass fraction of each component contained in the thermoplastic resin (B) as a weighted average.

Relative to 100 parts by mass of the resin (A) having a free radical polymerizable group, the content of the thermoplastic resin (B) is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, and further preferably 10 parts by mass or more, and preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and further preferably 30 parts by mass or less.

The free radical polymerization initiator (C) may be one or more, for example, a peroxide initiator, an azo initiator, etc.

As the peroxide initiator, there can be listed: benzoyl peroxide, tert-butyl perbenzoate, isopropyl hydroperoxide, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di(2-ethoxyethyl) peroxydicarbonate, tert-butyl peroxyneodecanoate, tert-butyl peroxypivalate, (3,5,5-trimethylhexyl) peroxide, dipropionyl peroxide, diacetyl peroxide, etc.

As the azo initiator, there can be listed: 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane 1-carbonitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile), dimethyl 2,2'-azobis(2-methylpropionate), 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis(2-hydroxymethacrylonitrile), 2,2'-azobis[2-(2-imidazolin-2-yl)propane], etc.

The content of the free radical polymerization initiator (C) is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and further preferably 1 parts by mass or more, and preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and further preferably 5 parts by mass or less, relative to 100 parts by mass of the resin (A) having a free radical polymerizable group.

The resin composition may further include a free radical polymerizable monomer (D). As the free radical polymerizable monomer (D), compounds having one or more free radical polymerizable groups may be listed, specifically, unsaturated fatty acids such as (meth) acrylic acid; (meth) acrylic acid esters such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate, glycidyl (meth) acrylate, and 2-hydroxyethyl (meth) acrylate; (meth) acrylamide, (meth) Nitrogen-containing (meth) acrylic monomers such as methacrylonitrile; aromatic vinyl compounds such as styrene, vinyl toluene, divinylbenzene, and tert-butylstyrene; multifunctional (meth) acrylic monomers such as ethylene glycol di(meth) acrylate, diethylene glycol di(meth) acrylate, 1,4-butanediol di(meth) acrylate, 1,6-hexanediol di(meth) acrylate, trihydroxymethylpropane tri(meth) acrylate, pentaerythritol tri(meth) acrylate, and pentaerythritol tetra(meth) acrylate, etc.

When the free radical polymerizable monomer (D) is included, its content is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, and preferably 80 parts by mass or less, more preferably 70 parts by mass or less, relative to 100 parts by mass of the resin (A) having a free radical polymerizable group.

The resin composition may contain other additives (E) in addition to the resin having a free radical polymerizable group (A), the thermoplastic resin (B), and the free radical polymerization initiator (C).

As the other additives, there can be listed: inorganic particles; antioxidants; light stabilizers such as hindered amine light stabilizers; ultraviolet absorbers; retarders; mold release agents; other thermoplastic resins; wax-based processing oils, cyclopentane-based processing oils, aromatic-based processing oils, organic polysiloxanes, mineral oils and other softeners and plasticizers; flame retardants; silane coupling agents; emulsifiers ; Conductive particles; Antistatic agent; Organic fiber; Organic fillers such as resin particles and rubber; Inorganic fillers such as pigments such as iron oxide; Reinforcers such as glass fiber, carbon fiber, and metal whiskers; Low shrinkage agent; Coloring agent; Physical pigment; Thixotropic agent; Organic phosphorus compounds such as phosphites, phosphonates, and phosphates; Leveling agent; Surfactant, etc.

In the resin composition, the content of the other additive (E) is preferably 30% by mass or less, more preferably 15% by mass or less, further preferably 10% by mass or less, and may also be 0% by mass.

The resin composition of the present invention is obtained by mixing a resin (A) having a free radical polymerizable group, a thermoplastic resin (B), a free radical polymerization initiator (C), and a free radical polymerizable monomer (D) or other additives (E) used as needed, and a cured product can be obtained by free radical polymerization. Free radical polymerization can be thermal polymerization or polymerization using active energy rays. As the shape of the cured product, laminates, casts, adhesive layers, coatings, films, composites impregnated in a reinforcing substrate (impregnated substrate), etc. can be listed, and the composite (impregnated substrate) can also be a prepreg as a semi-cured product.

The cured product of the resin composition forms a phase separation structure. When the resin (A) having a free radical polymerizable group, the thermoplastic resin (B), and the free radical polymerization initiator (C) are mixed, it is preferred that these components and other components used as necessary form a uniform phase. The mechanism for forming a phase separation structure in the cured product is not clear, but it is speculated as follows. That is, it is believed that as the polymerization of the free radical polymerizable group (A) proceeds, the molecular weight of the polymer derived from the resin (A) having a free radical polymerizable group increases, and the overall migration rate of the system is restricted. As a result, the compatibility of the polymer derived from the resin (A) having a free radical polymerizable group and the thermoplastic resin (B) decreases, thereby phase separation occurs (forming a phase separation structure).

The phase separation structure can be either a sea-island structure or a co-continuous structure. Whether there is phase separation in the hardened material can be confirmed by the following: when the fracture surface of the hardened material is observed using an atomic force microscope (AFM), two phases with different elastic moduli form a sea part and an island part, or form a co-continuous structure.

In the phase separation structure, the short diameter of the phase with a low elastic modulus is, for example, less than 500nm, preferably less than 200nm, and further preferably less than 100nm, and is, for example, greater than 1nm, and preferably greater than 10nm.

As the reinforcing substrate, glass fiber non-woven fabric, glass fiber woven fabric, paper substrate, etc. can be used.

The laminate formed by laminating the impregnated substrate is also included in the technical scope of the present invention. As the laminate, for example, it is preferred to have three or more layers of the impregnated substrate, and the reinforcing substrate in each layer is preferably different between the layers (for example, a composite laminate formed by laminating glass fiber woven fabric, glass fiber non-woven fabric, and paper substrate in the order of the surface). Examples include laminates obtained by laminating metal foil (such as copper foil, etc.) on both outer sides of the laminate as needed, and then compressing the metal foil and the laminate of the impregnated substrate while heating and hardening.

The resin composition of the present invention can be used for semiconductor sealing materials, printed wiring board materials, resin casting materials, adhesives, semiconductor packaging, etc. Among the above uses, in the use of insulating materials for printed wiring boards or electronic circuit substrates, it can be used as an insulating material for so-called electronic component embedded substrates in which passive parts such as capacitors or active parts such as IC chips are embedded in the substrate. Among them, in terms of high heat resistance, low thermal expansion, and solvent solubility, it is preferably used for printed wiring board materials, etc.

[Implementation example]

The following is a more detailed description of the present invention by giving examples.

[Synthesis Example 1] Synthesis of polyester resin A

779.1 parts by mass of bisphenol A type glycol ether (manufactured by DIC Corporation, "PANDEX (trademark) MB-601"), 132.9 parts by mass of isophthalic acid (hereinafter referred to as "iPA"), and 40.4 parts by mass of sebacic acid (hereinafter referred to as "SebA") were added to the reaction device, and the temperature was raised and stirred. Then, after the internal temperature was raised to 230°C, 0.10 parts by mass of TiPT was added, and the reaction was carried out at 230°C for 24 hours to synthesize a polyester resin.

The obtained polyester resin has a hydroxyl value of 36.9 and a number average molecular weight of 3,040.

[Synthesis Example 2] Synthesis of polyester resin B

886.9 parts by mass of bisphenol A type diol ether (produced by Nippon Emulsifier Co., Ltd., "BA-P13U diol"), 109.4 parts by mass of iPA, and 33.3 parts by mass of SebA were added to the reaction device, and the temperature was raised and stirred. Then, after the internal temperature was raised to 230°C, 0.10 parts by mass of TiPT was added, and the reaction was carried out at 230°C for 24 hours to synthesize the polyester resin.

The obtained polyester resin has a hydroxyl value of 15.5 and a number average molecular weight of 7,240.

[Synthesis Example 3] Synthesis of Polyester Resin C

430.9 parts by mass of 3-methyl-1,5-pentanediol and 692.4 parts by mass of SebA were added to the reaction device, and the temperature was raised and stirred. Then, after the internal temperature was raised to 220°C, 0.03 parts by mass of TiPT was added, and the reaction was carried out at 220°C for 12 hours to synthesize a polyester resin.

The obtained polyester resin has a hydroxyl value of 15.0 and a number average molecular weight of 4,488.

[Synthesis Example 4] Synthesis of Urethane Resin A

1,000.0 parts by mass of polytetramethylene glycol (manufactured by Mitsubishi Chemical Co., Ltd., "PTMG-1000") and 128.8 parts by mass of toluene diisocyanate (manufactured by Mitsui Chemicals SKC Polyurethane Co., Ltd., "Cosmonate (trademark) T-80") were added to the reaction apparatus. Then, after the temperature was raised to an external temperature of 80°C, the reaction was continued for 10 hours to synthesize urethane resin A.

The hydroxyl value of the obtained urethane resin is 28.0 and the number average molecular weight is 4,010.

[Implementation Example 1]

100 parts by mass of a vinyl ester resin ('Epiclon (trademark) CE-330-IM' manufactured by DIC Corporation) as an epoxy resin and 10 parts by mass of the polyester with OH groups at both ends obtained in Synthesis Example 1 were mixed in a mixing container and stirred until compatible. 1.25 parts by mass of a polymerization initiator ('Percumyl (trademark) H-80' manufactured by NOF Corporation) was added, stirred, and vacuum defoamed to obtain the vinyl ester resin composition (X1) of the present invention.

The vinyl ester resin composition was poured into a cast plate at room temperature and heat-cured at 100°C for 1 hour and then at 170°C for 2 hours. The cast plate was formed by sandwiching a 2mm thick rubber partition between glass plates. The fracture surface of the obtained hardened material was observed by atomic force microscopy (AFM), and it was confirmed that a sea part and an island part were formed.

[Example 2]

In addition to using 20 parts by weight of the polyester (polyester resin A) with OH groups at both ends obtained in Synthesis Example 1, an epoxy resin composition (X2) as a thermosetting composition of the present invention was obtained in the same manner as in Example 1. In the same manner as in Example 1, the fracture surface of the obtained cured product was observed by atomic force microscopy (AFM), and it was confirmed that two phases with different elastic moduli formed a co-continuous structure.

[Implementation Example 3]

The epoxy resin composition (X3) as the thermosetting composition of the present invention was obtained in the same manner as in Example 1, except that 10 parts by mass of the polyester with OH groups at both ends (polyester resin B) obtained in Synthesis Example 2 was used instead of 10 parts by mass of the polyester with OH groups at both ends (polyester resin A) obtained in Synthesis Example 1. In the same manner as in Example 1, the fracture surface of the obtained cured product was observed by atomic force microscopy (AFM), and it was confirmed that two phases with different elastic moduli formed a co-continuous structure.

[Implementation Example 4]

The epoxy resin composition (X4) as the thermosetting composition of the present invention was obtained in the same manner as in Example 1, except that 10 parts by mass of the polyester with OH groups at both ends (polyester resin C) obtained in Synthesis Example 3 was used instead of 10 parts by mass of the polyester with OH groups at both ends (polyester resin A) obtained in Synthesis Example 1. As in Example 1, the fracture surface of the obtained cured product was observed by atomic force microscopy (AFM), and it was confirmed that two phases with different elastic moduli formed a sea portion and an island portion.

[Implementation Example 5]

The epoxy resin composition (X5) as the thermosetting composition of the present invention was obtained in the same manner as in Example 1, except that 10 parts by mass of the polyurethane (urethane resin A) having OH groups at both ends obtained in Synthesis Example 4 was used instead of 10 parts by mass of the polyester (polyester resin A) having OH groups at both ends obtained in Synthesis Example 1. As in Example 1, the fracture surface of the obtained cured product was observed by atomic force microscopy (AFM), and it was confirmed that two phases with different elastic moduli formed a sea portion and an island portion.

[Comparative example 1]

In a mixing container, 1.25 parts by weight of a polymerization initiator ("Percumyl (trademark) H-80" manufactured by NOF Corporation) was added to 100 parts by weight of a vinyl ester resin ("Epiclon (trademark) CE-330-IM" manufactured by DIC Corporation) as an epoxy resin, and after stirring, vacuum defoaming was performed to obtain the vinyl ester resin composition (Y1) of the present invention.

The vinyl ester resin composition was poured into a cast plate at room temperature and heat-cured at 100°C for 1 hour and then at 170°C for 2 hours. The cast plate was formed by sandwiching a 2 mm thick rubber partition wall between glass plates. The fracture surface of the obtained hardened material was observed by atomic force microscopy (AFM), and no phase separation structure was observed.

[Comparative example 2]

The vinyl ester resin composition (Y2) of the present invention was obtained in the same manner as in Example 1, except that 10 parts by mass of a polyester with OH groups at both ends (manufactured by DIC Corporation, "Polylitte (trademark) OD-X-2921", hydroxyl group 208, number average molecular weight 540) was used instead of 10 parts by mass of a polyester with OH groups at both ends (polyester resin A) obtained in Synthesis Example 1. The fracture surface of the obtained cured product was observed by atomic force microscopy (AFM) in the same manner as in Comparative Example 1, but no phase separation structure was observed.

[Comparative example 3]

The vinyl ester resin composition (Y3) of the present invention was obtained in the same manner as in Example 1, except that 10 parts by mass of carboxylic acid-terminated polybutadiene (produced by Okamoto Oil Seisakusho Co., Ltd., "SB-20", number average molecular weight 350) was used instead of 10 parts by mass of the polyester (polyester resin A) having OH groups at both ends obtained in Synthesis Example 1. The fracture surface of the obtained cured product was observed by atomic force microscopy (AFM) in the same manner as in Comparative Example 1, but no phase separation structure was observed.

[Evaluation method of glass transition temperature (Tg) and storage elastic modulus (E')]

The vinyl ester resin composition obtained in the embodiment and the comparative example was poured into a cast plate at room temperature and heat-cured at 100°C for 1 hour and then at 170°C for 2 hours. The cast plate was formed by sandwiching a 2mm thick rubber partition between glass plates. The obtained hardened product was cut into a size of 5mm wide × 55mm long, and the storage elastic modulus (E') and loss elastic modulus (E") were measured under the following conditions.

When E'/E" is set as tanδ, the temperature at which tanδ is maximum is measured as the glass transition temperature (Tg, unit: ℃).

In addition, the storage elastic modulus (E') at 25°C was measured.

Measuring equipment: Dynamic viscoelasticity measuring machine (manufactured by SII Nanotechnology Co., Ltd.)

Model: DMA6100

Measuring temperature range: 0℃~300℃

Heating rate: 5℃/min

Frequency: 1Hz

Measurement mode: Bending

The evaluation criteria for heat resistance are as follows.

◎: Glass transition temperature is above 145℃

○: Glass transition temperature is above 130℃ and below 145℃

×: Glass transition temperature is less than 130℃

The evaluation criteria for storage elastic modulus are as follows.

◎：3,00MPa or less

○: More than 3,000MPa and less than 3,200MPa

×: More than 3,200MPa

[Evaluation method of copper foil adhesion]

The vinyl ester resin composition obtained in the embodiment and the comparative example was poured into a cast plate at room temperature and heat-cured at 100°C for 1 hour and then at 170°C for 2 hours. The cast plate was made by sandwiching a 2mm thick rubber partition wall between glass plates with copper foil on one side. The obtained hardened material was cut into a size of 10mm wide × 60mm long, and the 90° peel strength was measured using a peel tester.

Measuring equipment: Shimadzu automatic test machine (Autograph) (manufactured by Shimadzu Corporation)

Model: AG-1

Test speed: 50mm/min

The evaluation criteria for copper foil adhesion are as follows.

◎: Peel strength is 2.0N/cm or more

○: Peel strength is 1.5N/cm or more and less than 2.0N/cm

×: Peel strength less than 1.5N/cm

The results are shown in Table 1.

Examples 1 to 5 are examples of the present invention, and the copper foil has good adhesion, elastic modulus, and heat resistance. Comparative Example 1 is an example in which the hardened product does not undergo phase separation, and the copper foil has poor adhesion and elastic modulus.

Claims (10)

A resin composition comprises a resin (A) having a free radical polymerizable group, a thermoplastic resin (B), and a free radical polymerization initiator (C), wherein the resin (A) having a free radical polymerizable group comprises a vinyl ester resin, an unsaturated polyester resin, or a polyphenylene ether resin having a free radical polymerizable group, wherein the vinyl ester resin is a (meth)acrylic acid adduct of an epoxy resin, and the thermoplastic resin (B) comprises at least one selected from the group consisting of polyester polyols and polyurethane polyols, and the cured product of the resin composition forms a phase separation structure. The resin composition as described in claim 1, wherein the glass transition temperature of the thermoplastic resin (B) is above -100°C and below 50°C. The resin composition as described in claim 1 or claim 2, wherein the number average molecular weight of the thermoplastic resin (B) is greater than 500 and less than 10,000. The resin composition according to claim 1 or claim 2, wherein the solubility parameter of the thermoplastic resin (B) is 9 (cal/cm ³ ) ^0.5 or more and 13 (cal/cm ³ ) ^0.5 or less, wherein the solubility parameter of the thermoplastic resin (B) is obtained as a weighted average based on the solubility parameter and mass fraction of each component contained in the thermoplastic resin (B) according to the method of Ferdows. A cured product of a resin composition, wherein the resin composition is a resin composition as described in any one of claim 1 to claim 4. An impregnated substrate having a resin composition as described in any one of claim 1 to claim 4, and a reinforced substrate impregnated with the resin composition. A prepreg, which is a semi-cured product of the impregnated substrate as described in claim 6. A laminate having an impregnated substrate as described in claim 6. A printed wiring board having an impregnated substrate as described in claim 6. A semiconductor package having a printed wiring board as described in claim 9.