Thermosetting resin composition, cured product, semiconductor encapsulant, semiconductor device, insulating material for printed circuit board, and printed circuit board, as well as encapsulated modifier.

Abstract

The present disclosure provides: a thermosetting resin composition which has high dispersibility of a modified resin; and the like.　The present disclosure provides: a thermosetting resin composition which contains a thermosetting resin (A), a curing agent (B), a modifier (C), and at least one filler (D) that is selected from the group consisting of inorganic fine particles and fibers, wherein the modifier (C) has a capsule structure that has a core and a shell covering the surface of the core, and the core contains a modified resin (c); a cured product of the thermosetting resin composition; and a semiconductor sealing material, a semiconductor device, an insulating material for a printed wiring board, and a printed wiring board, each of which contains the thermosetting resin composition.　The present disclosure also provides a capsule-like modifier which has a core and a shell that covers the surface of the core, wherein the core contains a modified resin.

Description

[Technical Field]

[0001] This disclosure relates to thermosetting resin compositions, cured products, semiconductor encapsulants, semiconductor devices, insulating materials for printed circuit boards, printed circuit boards, and encapsulated modifiers. [Background technology]

[0002] Thermosetting resins are used in a wide range of fields, including as encapsulating materials to protect semiconductor elements such as capacitors, diodes, transistors, and thyristors, integrated circuits such as ICs and LSIs, and insulating materials used in printed circuit boards. However, molded products using the above-mentioned thermosetting resins are composites of various dissimilar materials, and the difference in thermal expansion coefficients of each material can cause warping during the manufacturing of the composite, leading to problems with dimensional accuracy. Furthermore, molded products using the above-mentioned thermosetting resins may develop defects due to differences in thermal expansion coefficients when exposed to temperature changes in the operating environment, often posing a significant manufacturing problem (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2003-82241 [Overview of the project] [Problems that the invention aims to solve]

[0004] To suppress warping and defects in molded products using thermosetting resin compositions, one method involves adding a modified resin to the thermosetting resin composition. However, thermosetting resin compositions prepared by kneading liquid modified resin together with powdered thermosetting resin and curing agents have the problem of reduced uniform dispersion of the modified resin.

[0005] The problem that this disclosure aims to solve is to provide a thermosetting resin composition in which the modified resin exhibits high uniform dispersibility. [Means for solving the problem]

[0006] This disclosure provides the following embodiments. [1] A thermosetting composition comprising a thermosetting resin (A), a curing agent (B), a modifier (C), and one or more fillers (D) selected from the group consisting of inorganic fine particles and fibers, The above-mentioned modifier (C) is a thermosetting resin composition having a capsule structure comprising a core and a shell covering the surface of the core, wherein the core contains a modified resin (c). [2] The modified resin (c) is the thermosetting resin composition described in [1] above, wherein the ether concentration is 11.5 mol / kg or more and 23 mol / kg or less. [3] The thermosetting resin composition according to [1] or [2] above, wherein the modified resin (c) comprises a polyether ester polyol resin and / or a urethane resin made from at least one of a polyether polyol and a polyether ester polyol. [4] The thermosetting resin composition according to any one of [1] to [3] above, wherein the number average molecular weight of the modified resin (c) is 500 or more and 20,000 or less. [5] The thermosetting resin composition according to any one of [1] to [4] above, wherein the shell comprises one or more selected from the group consisting of melamine resin, polyurea resin, and gelatin. [6] The thermosetting resin composition according to any one of [1] to [5] above, wherein the content of the modified resin (c) is 5% by mass or more and 45% by mass or less of the nonvolatile content of the components obtained by removing the filler (D) from the thermosetting resin composition. [7] A cured product of any of the thermosetting resin compositions described in [1] to [6] above. [8] A semiconductor encapsulant comprising the thermosetting resin composition described in any of [1] to [6] above. [9] A semiconductor device comprising the semiconductor encapsulant described in [8] above.

[10] An insulating material for printed wiring boards comprising the thermosetting resin composition described in any of [1] to [6] above.

[11] A printed circuit board comprising the insulating material for printed circuit boards described in

[10] above.

[12] A encapsulated modifier having a core and a shell covering the surface of the core, wherein the core contains a modified resin.

[13] The encapsulated modifier according to

[12] above, wherein the ether concentration of the modified resin is 11.5 mol / kg or more and 23 mol / kg or less.

[14] The encapsulated modifier according to

[12] or

[13] above, wherein the modified resin comprises a polyether ester polyol resin and / or a urethane resin made from at least one of a polyether polyol and a polyether ester polyol.

[15] The capsule modifier according to any one of

[12] to

[14] above, wherein the shell comprises one or more selected from the group consisting of melamine resin, polyurea resin, and gelatin. [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide a thermosetting resin composition in which the modified resin exhibits high uniform dispersibility. [Modes for carrying out the invention]

[0008] I. Thermosetting resin composition The thermosetting resin composition of this disclosure comprises a thermosetting resin (A), a curing agent (B), a modifier (C), and one or more fillers (D) selected from the group consisting of inorganic fine particles and fibers, wherein the modifier (C) has a capsule structure having a core and a shell covering the surface of the core, and the core contains the modifier (c).

[0009] According to the thermosetting resin composition of this disclosure, by using a modifier (C) in a capsule structure containing a modified resin (c), the uniform dispersion of the modifier (C) and modified resin (c) within the thermosetting resin composition is improved. Furthermore, when the thermosetting resin composition of this disclosure is subjected to loads such as heating or pressurization (hereinafter referred to as external loads), the capsules of the modifier (C) break, and the encapsulated modified resin (c) is released and diffused. As a result, in the cured product of the thermosetting resin composition, the uneven distribution of the modified resin (c) is suppressed, resulting in a uniformly dispersed state, and the performance of the modified resin (c) is more easily expressed uniformly.

[0010] Examples of the thermosetting resin (A) include epoxy resins, benzoxazine structure-containing resins, maleimide resins, vinylbenzyl compounds, acrylic compounds, copolymers of styrene and maleic anhydride, etc. These resins may be used individually or in combination of two or more. Among these, it is preferable that the thermosetting resin (A) contains at least an epoxy resin.

[0011] Furthermore, since it readily forms a phase separation structure with the modified resin (c) and readily achieves a low coefficient of thermal expansion and a low modulus of elasticity of the cured product of the thermosetting resin composition, the thermosetting resin (A) is preferably epoxy resin and / or maleimide resin among the resins exemplified above, and more preferably epoxy resin.

[0012] Examples of the epoxy resins mentioned above include bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenyl type epoxy resin, tetramethylbiphenyl type epoxy resin, diglycidyloxynaphthalene compounds (1,6-diglycidyloxynaphthalene, 2,7-diglycidyloxynaphthalene, etc.), phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, triphenylmethane type epoxy resin, tetraphenylethane type epoxy resin, and dicyclopentadiene-phenol addition reaction type epoxy resin. Various epoxy resins can be used, including silicic acid resins, phenol aralkyl epoxy resins, naphthol novolac epoxy resins, naphthol aralkyl epoxy resins, naphthol-phenol co-condensed novolac epoxy resins, naphthol-cresol co-condensed novolac epoxy resins, aromatic hydrocarbon formaldehyde resin-modified phenol resin-type epoxy resins, biphenyl novolac epoxy resins, naphthalene skeleton-containing epoxy resins such as 1,1-bis(2,7-diglycidyloxy-1-naphthyl)alkanes, and phosphorus-modified epoxy resins obtained by introducing phosphorus atoms into these various epoxy resins.

[0013] Among these, cresol novolac type epoxy resins, phenol aralkyl type epoxy resins, biphenyl novolac type epoxy resins, naphthol novolac type epoxy resins containing a naphthalene skeleton, naphthol aralkyl type epoxy resins, naphthol-phenol copolymer novolac type epoxy resins, naphthol-cresol copolymer novolac type epoxy resins, crystalline biphenyl type epoxy resins, tetramethylbiphenyl type epoxy resins, xanthene type epoxy resins, and alkoxy group-containing aromatic ring-modified novolac type epoxy resins (compounds in which a glycidyl group-containing aromatic ring and an alkoxy group-containing aromatic ring are linked with formaldehyde) are particularly preferred because they yield cured products with excellent heat resistance.

[0014] From the perspective of obtaining a cured product with excellent heat resistance, the above epoxy resin may contain an aromatic epoxy resin. The aromatic epoxy resin may be any resin having an aromatic chemical structure, and includes, for example, monocyclic aromatics, polycyclic aromatics, and aromatic heterocycles. Among them, it is preferable to contain a condensed ring structure-containing epoxy resin. Examples of the condensed ring in the condensed ring structure-containing epoxy resin include a naphthalene ring, an anthracene ring, a phenanthrene ring, etc., and a naphthalene ring is particularly preferable.

[0015] The above epoxy resin may be in a liquid state, a solid state, or a crystalline state at normal temperature (25°C). When the thermosetting resin (A) contains two or more kinds of epoxy resins, the above epoxy resin may contain two or more kinds of epoxy resins having the same properties, or two or more kinds of epoxy resins having different properties may be used in combination. When the thermosetting resin composition of the present disclosure is used as a liquid encapsulant, the above epoxy resin is preferably in a liquid state at normal temperature. On the other hand, when the thermosetting resin composition of the present disclosure is used as a solid encapsulant, the above epoxy resin is preferably in a solid state or a crystalline state at normal temperature.

[0016] As the above maleimide resin, for example, resins represented by any of the following structural formulas can be used.

[0017]

Chemical formula

[0018] [In formula (1), R 1 represents an a1-valent organic group, R 2 and R 3 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and a1 represents an integer of 1 or more.]

[0019]

Chemical formula

[0020] [In formula (2), R 4 , R 5 and R 6 Each of these independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, a halogen atom, a hydroxyl group, or an alkoxy group having 1 to 20 carbon atoms, L 1 and L 2 Each of these independently represents a saturated hydrocarbon group with 1 to 5 carbon atoms, an aromatic hydrocarbon group with 6 to 10 carbon atoms, or a group with 6 to 15 carbon atoms that is a combination of a saturated hydrocarbon group and an aromatic hydrocarbon group. Each of a3, a4, and a5 independently represents an integer from 1 to 3, and n represents an integer from 0 to 10.

[0021] The total content of the epoxy resin and the maleimide resin in the thermosetting resin (A) is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more, with an upper limit of 100% by mass.

[0022] The content of the thermosetting resin (A) is preferably 3% by mass or more, more preferably 5% by mass or more, preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less, based on the nonvolatile content of the components of the thermosetting resin composition excluding the filler (D).

[0023] The thermosetting resin (A) described above is preferably solid at room temperature, from the viewpoint of more significantly exhibiting the effects of the present invention by using the encapsulated modifier (C). Furthermore, if the thermosetting resin (A) contains two or more types of thermosetting resins, it is preferable that two or more of the thermosetting resins are solid, but it may also contain a thermosetting resin that is semi-solid or liquid at room temperature in combination with a solid thermoplastic resin. In this specification, room temperature means 25°C.

[0024] The curing agent (B) described above can be any agent capable of curing the thermosetting resin composition, and for example, amine compounds, amide compounds, activated ester resins, acid anhydrides, phenol resins, cyanate ester resins, etc. can be used. Among these, at least one selected from amine compounds, activated ester resins, phenol resins, and cyanate resins is preferred, and amine compounds and phenol resins are more preferred.

[0025] Examples of the above-mentioned amine compounds include diethyltoluenediamine, diaminodiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, imidazole, BF3-amine complex, guanidine derivatives, and the like.

[0026] Examples of the amide compounds mentioned above include dicyandiamide, polyamide resins synthesized from a linolenic acid dimer and ethylenediamine, and the like.

[0027] As the above-mentioned active ester resin, compounds having two or more highly reactive ester groups in one molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds, are preferably used. The above-mentioned active ester resin is preferably obtained by a condensation reaction between a carboxylic acid compound and / or a thiocarboxylic acid compound and a hydroxy compound and / or a thiol compound. Particularly from the viewpoint of improving heat resistance, an active ester resin obtained from a carboxylic acid compound or its halide and a hydroxy compound is preferred, and an active ester resin obtained from a carboxylic acid compound or its halide and a phenol compound and / or a naphthol compound is more preferred. Examples of carboxylic acid compounds include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, pyromellitic acid, etc., or their halides. Examples of phenol compounds or naphthol compounds that can be used include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, dihydroxydiphenyl ether, phenolphthalein, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, dicyclopentadiene-phenol addition resins, etc.

[0028] Examples of the above-mentioned acid anhydrides include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, and methylhexahydrophthalic anhydride.

[0029] The above phenol resins include phenol novolac resin, cresol novolac resin, aromatic hydrocarbon formaldehyde resin-modified phenol resin, dicyclopentadienephenol addition resin, phenol aralkyl resin (Zyloc resin), naphthol aralkyl resin, triphenylol methane resin, tetraphenylolethane resin, naphthol novolac resin, naphthol-phenol co-condensed novolac resin, naphthol-cresol co-condensed novolac resin, biphenyl-modified phenol resin (a compound containing polyvalent phenolic hydroxyl groups linked to a phenol nucleus by a bismethylene group), naphthalene skeleton-containing phenol resin, and biphenyl-modified naphthol resin (a compound containing polyvalent naphthol groups linked to a phenol nucleus by a bismethylene group). Polyvalent phenolic hydroxyl group-containing resins such as aminotriazine-modified phenol resins (polyvalent phenolic hydroxyl group-containing compounds in which the phenol nucleus is linked with melamine, benzoguanamine, etc.) and alkoxy-group-containing aromatic ring-modified novolac resins (polyvalent phenolic hydroxyl group-containing compounds in which the phenol nucleus and alkoxy-group-containing aromatic ring are linked with formaldehyde), bisphenol compounds such as bisphenol A and bisphenol F, biphenyl compounds such as biphenyl and tetramethylbiphenyl; triphenylolle methane and tetraphenylolethane; dicyclopentadiene-phenol addition reaction type resins, and phosphorus-modified phenol compounds obtained by introducing phosphorus atoms into these various phenolic hydroxyl group-containing compounds can be used.

[0030] The above-mentioned cyanate ester resins can be one or more types, for example, bisphenol A type cyanate ester resin, bisphenol F type cyanate ester resin, bisphenol E type cyanate ester resin, bisphenol S type cyanate ester resin, bisphenol sulfide type cyanate ester resin, phenylene ether type cyanate ester resin, naphthylene ether type cyanate ester resin, biphenyl type cyanate ester resin, tetramethylbiphenyl type cyanate ester resin, polyhydroxynaphthalene type cyanate ester resin, phenol novolac type cyanate ester resin, cresol novolac type cyanate ester resin. Fats, triphenylmethane-type cyanate ester resins, tetraphenylethane-type cyanate ester resins, dicyclopentadiene-phenol addition reaction-type cyanate ester resins, phenol aralkyl-type cyanate ester resins, naphthol novolac-type cyanate ester resins, naphthol aralkyl-type cyanate ester resins, naphthol-phenol co-condensed novolac-type cyanate ester resins, naphthol-cresol co-condensed novolac-type cyanate ester resins, aromatic hydrocarbon formaldehyde resin-modified phenol resin-type cyanate ester resins, biphenyl-modified novolac-type cyanate ester resins, anthracene-type cyanate ester resins, etc. can be used.

[0031] The content of the curing agent (B) is preferably 1% by mass or more, more preferably 3% by mass or more, preferably 90% by mass or less, and more preferably 80% by mass or less, based on the nonvolatile content of the components of the thermosetting resin composition excluding the filler (D).

[0032] The curing agent (B) described above is preferably solid at room temperature, from the viewpoint of more significantly exhibiting the effects of the present invention by using the encapsulated modifier (C), but it may also be semi-solid or liquid. If the curing agent (B) described above contains two or more curing agents, it is preferable that two or more curing agents are solid, but it may also contain a curing agent that is semi-solid or liquid at room temperature in combination with a solid curing agent.

[0033] The above-mentioned modifier (C) has a capsule structure comprising a core and a shell covering the surface of the core. The core also contains a modifier resin (c).

[0034] When a liquid modifier resin is mixed with materials such as a powdered thermosetting resin (A) or a curing agent (B) in the preparation of a thermosetting resin composition, the modifier resin is difficult to disperse uniformly in the composition, and the modifier resin may be unevenly distributed in the cured product of the composition, resulting in an inability to uniformly exhibit physical properties. In contrast, the modifier (C) in this disclosure has a capsule structure containing the modifier resin (c), so it can be uniformly mixed with materials such as a powdered thermosetting resin (A) or a curing agent (B). As a result, the thermoplastic resin composition has a uniform dispersion of the modifier (C), and the uniform dispersibility of the modifier resin (c), which is the contents of the capsule-shaped modifier (C), is also improved.

[0035] Furthermore, in the thermosetting resin composition of this disclosure in which encapsulated modifier (C) is dispersed, applying an external load such as heating or pressurizing causes the shell of the modifier (C) to break or dissolve, releasing and diffusing the core modifier resin (c) into the composition. As a result, in the cured product of the thermosetting resin composition of this disclosure, the modifier resin (c) is uniformly dispersed in the cured product due to the uniform dispersion of the encapsulated modifier (C), thereby improving the physical properties by adding the modifier resin (c) and enabling the uniform expression of these physical properties.

[0036] <core> The core of the above-mentioned modifier (C) contains a modified resin (c). The material constituting the core (hereinafter sometimes referred to as the core material) only needs to contain the modified resin (c) as the most abundant essential component (it is the main component), and may consist only of the modified resin (c), or it may contain the modified resin (c) and other components. The content of the modified resin (c) in the material constituting the core should be such that the proportion of the modified resin (c) is the largest, for example, it may be 80% by mass or more, preferably 90% by mass or more, more preferably 95% by mass or more, even more preferably 98% by mass or more, and particularly preferably 100% by mass (i.e., the core is composed only of the modified resin (c)).

[0037] The modified resin (c) described above is compatible with the thermosetting resin (A) and curing agent (B) contained in the thermosetting resin composition of this disclosure, while in the cured product of the thermosetting resin composition, it is a component whose compatibility with the reaction product (cured product) of the thermosetting resin (A) and curing agent (B) is reduced, allowing for phase separation. The thermosetting resin composition and its cured product of this disclosure, by including the modified resin (c), can achieve and / or simultaneously improve physical properties such as a reduction in thermal expansion coefficient and elastic modulus, and suppression of warping.

[0038] Examples of the modified resin (c) mentioned above include polyester resin, polyurethane resin, polyether resin, polycarbonate resin, acrylic resin, epoxy resin, phenolic resin, rosin-based resin, polyester polyol resin, polyether polyol resin, and polyether ester polyol resin.

[0039] The modified resin (c) described above may be a thermoplastic resin or a thermosetting resin, but a thermoplastic resin is preferred.

[0040] The modified resin (c) described above preferably has at least one functional group selected from the group consisting of hydroxyl groups and carboxyl groups (hereinafter sometimes referred to as a specific functional group), and more preferably has one or more hydroxyl groups.

[0041] Preferred resins having the above-mentioned specific functional groups include, for example, polyester resins, polyurethane resins, polyester polyol resins, polyether polyol resins, and polyether ester polyol resins. One or more of these can be used.

[0042] (Polyester resin) Examples of the polyester resins mentioned above include polyester resins obtained by reacting a polyol with a polycarboxylic acid; polyester resins obtained by ring-opening polymerization of cyclic ester compounds; and polyester resins obtained by copolymerizing these. The polyester resins may be used individually or in combination of two or more.

[0043] The above polyester resin preferably has a specific functional group (at least one functional group selected from the group consisting of hydroxyl groups and carboxyl groups) at its terminal end, and is particularly preferably a hydroxyl group.

[0044] One or more polyols can be used in the production of the above polyester resin. Examples include aliphatic polyols such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, and 1,3-butanediol; polyols having an alicyclic structure such as cyclohexanedimethanol; polyols having an aromatic structure such as bisphenol A and bisphenol F; and polyols obtained by modifying the above aromatic polyols with alkylene oxide.

[0045] Among these, polyols having an alicyclic structure, polyols having an aromatic structure, and polyols obtained by modifying polyols having an aromatic structure with alkylene oxide are preferred, and polyols obtained by modifying polyols having an aromatic structure with alkylene oxide are more preferred.

[0046] The number-average molecular weight of the above polyol is preferably 50 or more, more preferably 100 or more. Furthermore, the number-average molecular weight of the above polyol is preferably 1,500 or less, more preferably 1,000 or less, and even more preferably 700 or less. The number-average molecular weight of the polyol is calculated based on its hydroxyl value.

[0047] Examples of alkylene oxides used to modify the polyol having the above aromatic structure include alkylene oxides having 2 to 4 carbon atoms (preferably 2 to 3), such as ethylene oxide and propylene oxide. The number of moles of alkylene oxide added is preferably 2 moles or more, more preferably 4 moles or more, preferably 20 moles or less, and more preferably 16 moles or less, per mole of the polyol having the above aromatic structure.

[0048] The above polycarboxylic acids can be one or more types, and examples include 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 naphthalenedicarboxylic acid; and their anhydrides or esterified products.

[0049] In particular, it is preferable to include an aliphatic polycarboxylic acid. The content of the aliphatic polycarboxylic acid is preferably 5 mol% or more, more preferably 10 mol% or more, and preferably 100 mol% or less, of the total amount of the polycarboxylic acids.

[0050] In a preferred embodiment, the polycarboxylic acid may include both aliphatic polycarboxylic acids and aromatic polycarboxylic acids. The content ratio of aromatic polycarboxylic acids to aliphatic polycarboxylic acids is preferably 1 / 99 or more, more preferably 30 / 70 or more, even more preferably 50 / 50 or more, preferably 99 / 1 or less, more preferably 90 / 10 or less, and even more preferably 85 / 15 or less, on a molar basis.

[0051] The content ratio (polyol / polycarboxylic acid) of polyol to polycarboxylic acid used in the production of the above polyester resin is preferably 20 / 80 or more, more preferably 30 / 70 or more, even more preferably 40 / 60 or more, preferably 99 / 1 or less, more preferably 90 / 10 or less, and even more preferably 85 / 15 or less, on a mass basis.

[0052] The above cyclic ester compounds can be one or more, and examples include γ-butyrolactone, γ-valerolactone, δ-valerolactone, ε-caprolactone, ε-methylcaprolactone, ε-ethylcaprolactone, ε-propylcaprolactone, 3-penten-4-olide, 12-dodecanolide, and γ-dodecanolactone.

[0053] The content of oxyalkylene units having 4 or more carbon atoms in the above polyester resin is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 3% by mass or less, and particularly preferably 1% by mass or less.

[0054] The above polyester resin can be produced, for example, by reacting the above polyol with the above polycarboxylic acid. The reaction temperature is preferably 190°C or higher, more preferably 200°C or higher, preferably 250°C or lower, and more preferably 240°C or lower. The reaction time is preferably 1 hour or more and 100 hours or less.

[0055] In the above reaction, a catalyst may be used in the presence of the catalyst. One or more types of catalysts can be used, and examples include titanium-based catalysts such as tetraisopropyl titanate and tetrabutyl titanate; tin-based catalysts such as dibutyltin oxide; and organic sulfonic acid-based catalysts such as p-toluenesulfonic acid.

[0056] The amount of the catalyst is preferably 0.0001 parts by mass or more, more preferably 0.0005 parts by mass or more, preferably 0.01 parts by mass or less, and more preferably 0.005 parts by mass or less, based on 100 parts by mass of the total of the polyol and the polycarboxylic acid.

[0057] (Polyurethane resin) The polyurethane resin described above is a reaction product of a polyol and a polyisocyanate. The polyurethane resin may be used alone or in combination of two or more types.

[0058] The polyurethane resin described above preferably has a specific functional group (at least one functional group selected from the group consisting of hydroxyl groups and carboxyl groups) at its terminal end, and is particularly preferably a hydroxyl group. Furthermore, it is preferable that the polyurethane resin does not have an isocyanate group at its terminal end.

[0059] -Polyol- Examples of polyols used in the production of the above-mentioned polyurethane resin include polyether polyols, polyester polyols, polyether ester polyols, and polycarbonate polyols. These may be used individually or in combination of two or more types.

[0060] The number-average molecular weight of the polyol used in the production of the above polyurethane resin is preferably 500 or more, more preferably 700 or more, preferably 15,000 or less, and more preferably 10,000 or less.

[0061] Examples of the above-mentioned polyether polyols include those obtained by addition polymerization (ring-opening polymerization) of alkylene oxide using one or more compounds having two or more active hydrogen atoms as initiators.

[0062] Preferred initiators include compounds having two or more active hydrogen atoms, such as linear diols like ethylene glycol, diethylene glycol, triethylene glycol, trimethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol; branched diols like neopentyl glycol, 1,2-propanediol, and 1,3-butanediol; triols like glycerin, trimethylolethane, trimethylolpropane, and pyrogallol; polyols like sorbitol, sucrose, and aconite sugar; tricarboxylic acids like aconitic acid, trimellitic acid, and hemimeric acid; phosphoric acid; polyamines like ethylenediamine and diethylenetriamine; triisopropanolamine; phenolic acids like dihydroxybenzoic acid and hydroxyphthalic acid; and 1,2,3-propanetrithiol.

[0063] Examples of the alkylene oxides mentioned above include ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, and tetrahydrofuran.

[0064] Examples of the polyether polyols mentioned above include polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. Polypropylene glycol is obtained by addition polymerization (ring-opening polymerization) of propylene oxide to the above initiator. Polyoxytetramethylene glycol is obtained by addition polymerization (ring-opening polymerization) of tetrahydrofuran to the above initiator. Among these, polypropylene glycol is preferred because it can form a phase separation structure in the cured product of the thermosetting resin composition, thereby more effectively reducing the coefficient of thermal expansion and the modulus of elasticity, and can better achieve both suppression of warping during manufacturing and low viscosity.

[0065] Examples of the above-mentioned polyester polyols include polyester polyols obtained by esterifying a low molecular weight polyol (for example, a polyol with a molecular weight of 50 to 300) with a polycarboxylic acid; polyester polyols obtained by ring-opening polymerization of cyclic ester compounds such as ε-caprolactone; and copolymerized polyester polyols thereof.

[0066] The low molecular weight polyols mentioned above can be polyols with a molecular weight of approximately 50 to 300. Examples include aliphatic polyols with 2 to 6 carbon atoms such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, and 1,3-butanediol; polyols containing alicyclic structures such as 1,4-cyclohexanediol and cyclohexanedimethanol; and polyols containing aromatic structures such as bisphenol compounds like bisphenol A and bisphenol F, and their alkylene oxide adducts.

[0067] Examples of the polycarboxylic acids mentioned above include 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 naphthalenedicarboxylic acid; and anhydrides or ester-forming derivatives of the aliphatic polycarboxylic acids and aromatic polycarboxylic acids.

[0068] Examples of the polyether ester polyols mentioned above include reaction products of polyether polyols and polybasic acids, and reaction products of polyether polyols and lactone compounds.

[0069] As the polyether polyol constituting the above-mentioned polyether ester polyol, the polyether polyols described above can be used. Among them, polypropylene glycol is preferred from the viewpoint of being able to form a phase separation structure in the cured product of the thermosetting resin composition, thereby more effectively reducing the coefficient of thermal expansion and the elastic modulus, and thus better achieving both suppression of warping during manufacturing and low viscosity.

[0070] Examples of the polybasic acids that constitute the polyether ester polyols include aliphatic polycarboxylic acids such as succinic acid, adipic acid, sebacic acid, and dodecanedicarboxylic acid; and aromatic polycarbonates such as terephthalic acid, isophthalic acid, phthalic acid, and naphthalenedicarboxylic acid.

[0071] Examples of the lactone compounds that constitute the polyether ester polyol resin include γ-butyrolactone, γ-valerolactone, δ-valerolactone, ε-caprolactone, ε-methylcaprolactone, ε-ethylcaprolactone, ε-propylcaprolactone, 3-penten-4-olide, 12-dodecanolide, and γ-dodecanolactone. Among these, ε-caprolactone is preferred.

[0072] Examples of the polycarbonate polyols mentioned above include reaction products of carbonate esters and polyols, and reaction products of phosgene and bisphenol A, etc.

[0073] Examples of the above-mentioned carbonate esters include methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclocarbonate, and diphenyl carbonate.

[0074] Examples of polyols that can react with the above-mentioned carbonate esters include the polyols exemplified above as low molecular weight polyols; and high molecular weight polyols (number average molecular weight of 500 to 5,000) such as polyether polyols (polyethylene glycol, polypropylene glycol, etc.) and polyester polyols (polyhexamethylene adipate, etc.).

[0075] -Polyisocyanate- The above polyisocyanates can be one or more types, and examples include aromatic polyisocyanates such as 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate, crude diphenylmethane diisocyanate, phenylene diisocyanate, triene diisocyanate, naphthalene diisocyanate, xylylene diisocyanate, and tetramethylxylylene diisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate and lysine diisocyanate; and polyisocyanates containing alicyclic structures such as cyclohexane diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, and dicyclohexylmethane diisocyanate.

[0076] —Polyurethane resin— The equivalent ratio [isocyanate groups / hydroxyl groups] of hydroxyl groups in the polyol used in the production of the polyurethane resin and isocyanate groups in the polyisocyanate is preferably 0.1 or more, more preferably 0.2 or more, preferably 0.9 or less, and more preferably 0.7 or less on a molar basis.

[0077] Among the polyurethane resins mentioned above, urethane resins made from at least one of polyether polyols and polyether ester polyols are preferred because they can form a phase separation structure in the cured product of a thermosetting resin composition, thereby more effectively reducing the coefficient of thermal expansion and the modulus of elasticity, and thus better achieve both suppression of warping during manufacturing and low viscosity. In particular, urethane resins made from at least one of polyether polyols containing polypropylene glycol and polyether ester polyols containing polypropylene glycol are preferred because they can exhibit the above-mentioned effects to a greater extent.

[0078] The above polyurethane resin can be produced by reacting a polyol with a polyisocyanate. If the terminal end of the obtained polyurethane resin is an isocyanate group, a chain extender having a hydroxyl group may be reacted further.

[0079] One or more types of chain extenders having hydroxyl groups can be used, and examples include glycol compounds such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, hexamethylene glycol, saccharose, methylene glycol, glycerin, and sorbitol; phenol compounds such as bisphenol A, 4,4'-dihydroxydiphenyl, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl sulfone, hydrogenated bisphenol A, and hydroquinone; and water.

[0080] (Polyester polyol resin) Examples of the polyester polyol resins mentioned above include the polyester polyols described and illustrated in the section "(Polyurethane Resin)" above. These may be used individually or in combination of two or more types.

[0081] (Polyether polyol resin) Examples of the polyether polyol resins mentioned above include the polyether polyols described and illustrated in the "(Polyurethane Resin)" section above. More specifically, examples include polyether polyols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. These may be used individually or in combination of two or more. Among these, polypropylene glycol is preferred because it can form a phase separation structure in the cured product of the thermosetting resin composition, thereby more effectively reducing the coefficient of thermal expansion and the modulus of elasticity, and can better achieve both suppression of warping during manufacturing and low viscosity.

[0082] (Polyether ester polyol resin) Examples of the polyether ester polyol resins mentioned above include the polyether ester polyols described and illustrated in the "(Polyurethane Resins)" section above. More specifically, examples include reaction products of polyether polyols with polybasic acids; and reaction products of polyether polyols with lactone compounds. These may be used individually or in combination of two or more.

[0083] As the polyether polyol constituting the above-mentioned polyether ester polyol resin, the polyether polyols described and exemplified in the "(Polyurethane Resin)" section above can be used. Among these, polypropylene glycol is preferred because it can form a phase separation structure in the cured product of the thermosetting resin composition, thereby more effectively reducing the coefficient of thermal expansion and the modulus of elasticity, and can better achieve both suppression of warping during manufacturing and low viscosity.

[0084] Examples of the polybasic acids that constitute the above-mentioned polyether ester polyol resin include aliphatic polycarboxylic acids such as succinic acid, adipic acid, sebacic acid, and dodecanedicarboxylic acid; and aromatic polycarbonates such as terephthalic acid, isophthalic acid, phthalic acid, and naphthalenedicarboxylic acid.

[0085] Examples of the lactone compounds that constitute the polyether ester polyol resin include γ-butyrolactone, γ-valerolactone, δ-valerolactone, ε-caprolactone, ε-methylcaprolactone, ε-ethylcaprolactone, ε-propylcaprolactone, 3-penten-4-olide, 12-dodecanolide, and γ-dodecanolactone. Among these, ε-caprolactone is preferred.

[0086] (Modified resin (c)) The modified resin (c) described above preferably includes a resin containing a functional group selected from the group consisting of hydroxyl groups and carboxyl groups, in order to form a phase separation structure in the cured product of the thermosetting resin composition of this disclosure, thereby more effectively reducing the coefficient of thermal expansion and the modulus of elasticity, and to better achieve both warp suppression and low viscosity. In particular, it preferably includes one or more resins selected from the group consisting of polyether polyol resins, polyether ester polyol resins, and urethane resins made from at least one of polyether polyol and polyether ester polyol as raw materials. Polyether ester polyol resins and / or urethane resins made from at least one of polyether polyol and polyether ester polyol as raw materials are more preferred, and polyether ester polyol resins are even more preferred. These resins may be used alone or in combination of two or more. Furthermore, the ether concentration of the resin selected from the above group is not particularly limited, as it makes it easier to achieve the above-mentioned effects, but it is preferably within the range of the ether concentration of the modified resin (c) described later.

[0087] The above-mentioned modified resin (c) may have a functional value of 0 mgKOH / g or more, where the number of functional groups (specific functional groups) selected from the group consisting of hydroxyl groups and carboxyl groups is 0 mgKOH / g or more, preferably 0 mgKOH / g or more and 200 mgKOH / g or less, more preferably 0.5 mgKOH / g or more and 150 mgKOH / g or less, and even more preferably 1 mgKOH / g or more and 120 mgKOH / g or less. If the above-mentioned modified resin (c) is a mixture of two or more modified resins, the hydroxyl value of the above-mentioned modified resin (c) can be calculated as a weighted average value based on the hydroxyl value and content (by mass) of each resin.

[0088] The above-mentioned modified resin (c) may have zero or more functional groups (specific functional groups) selected from the group consisting of hydroxyl groups and carboxyl groups per molecule, and may have more than zero, preferably one or more, and more preferably two or more. Furthermore, there is no particular upper limit to the number of above functional groups per molecule, but it is preferably six or less, more preferably four or less, even more preferably three or less, and particularly preferably two or less.

[0089] If the modified resin (c) has a specific functional group, the position of the specific functional group in the modified resin (c) is not particularly limited, but it is preferable that it be located at at least one end of the modified resin (c), and more preferably at both ends.

[0090] The modified resin (c) described above preferably has low viscosity. In the thermosetting resin composition, the core of the modifier (C) breaks and the modified resin (c) is released and diffused, thereby lowering the viscosity of the composition when it melts at high temperatures. The viscosity of the modified resin (c) described above is preferably 100 mPa·s or less, and more preferably 50 mPa·s or less, at 150°C. The lower limit of the viscosity of the modified resin (c) at 150°C is not particularly limited as long as it is 0 mPa·s or more, but 1 mPa·s or more is preferred.

[0091] Furthermore, considering suitability for the encapsulation process, the viscosity of the modified resin (c) is preferably 20,000 mPa·s or less, more preferably 5,000 mPa·s or less, and even more preferably 1,000 mPa·s or less at 25°C. If the viscosity is too high, it may be difficult to encapsulate it in the shell material by the general method described later, and it may not be possible to prepare a encapsulated modifier. The lower limit of the viscosity of the modified resin (c) at 25°C is not particularly limited as long as it is 0 mPa·s or higher, but 50 mPa·s or higher is preferred.

[0092] The viscosity of the above-mentioned modified resin (c) is a value measured by a method in accordance with JIS K6901-1986.

[0093] The ether concentration of the above-mentioned modified resin (c) is not particularly limited, but is preferably 11.5 mol / kg or more and 23 mol / kg or less, and more preferably 13 mol / kg or more and 20 mol / kg or less. When the above-mentioned modified resin (c) uses a single resin, the ether concentration of the above-mentioned modified resin (c) represents the concentration of ether groups relative to the total mass of the raw materials of the above-mentioned resin. When the above-mentioned modified resin (c) uses a mixture of multiple resins, the ether concentration of the resin with the highest ether concentration in the mixture represents the concentration of ether groups.

[0094] A preferred embodiment of the thermosetting resin of this disclosure is a combination in which the ether concentration of the modified resin (c) is within the above range, and the thermosetting resin (A) is an epoxy resin and / or a maleimide resin. In particular, a combination is preferred in which the modified resin (c) is a resin containing a functional group selected from the group consisting of hydroxyl groups and carboxyl groups, and the thermosetting resin (A) is an epoxy resin and / or a maleimide resin. More preferably, the modified resin (c) is one or more resins selected from the group consisting of polyether polyol resins, polyether ester polyol resins, and urethane resins made from at least one of polyether polyol and polyether ester polyol, and the thermosetting resin (A) is an epoxy resin and / or a maleimide resin. These combinations make it easier to form a phase separation structure in the cured product of the thermosetting resin composition and make it easier to achieve a low coefficient of thermal expansion and a low modulus of elasticity.

[0095] The number average molecular weight of the modified resin (c) is not particularly limited, but it is preferably 500 to 20,000, and more preferably 1,000 to 10,000, as this allows the effects of the modified resin (c) to be easily achieved in the thermosetting resin composition. When the number average molecular weight of the modified resin (c) is within the above range, the viscosity of the thermosetting resin can be lowered when the shell of the modifier (C) breaks and the modified resin (c) diffuses in the thermosetting resin composition before or during curing. Furthermore, a phase separation structure can be formed, which can more effectively reduce the thermal expansion coefficient and elastic modulus of the cured product, thereby achieving both suppression of warping during manufacturing and low viscosity.

[0096] The number-average molecular weight of the above-mentioned modified resin (c) is shown as the value measured by gel permeation chromatography (GPC) under the following conditions. Measurement device: High-speed GPC device (HLC-8220GPC manufactured by Tosoh Corporation) Columns: The following columns manufactured by Tosoh Corporation were used, connected in series. "TSKgel G5000" (7.8mm I.D. x 30cm) x 1 "TSKgel G4000" (7.8mm I.D. x 30cm) x 1 "TSKgel G3000" (7.8mm I.D. x 30cm) x 1 "TSKgel G2000" (7.8mmI.D. x 30cm) x 1 Detector: RI (Differential Refractometer) Column temperature: 40℃ Eluent: Tetrahydrofuran (THF) Flow rate: 1.0mL / min Injection volume: 100 μL (tetrahydrofuran solution with a sample concentration of 0.4% by mass) Standard samples: Calibration curves were created using the following standard polystyrene samples.

[0097] (Standard polystyrene) TSKgel Standard Polystyrene A-500, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene A-1000, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene A-2500, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene A-5000, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-1, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-2, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-4, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-10, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-20, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-40, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-80, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-128, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-288, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-550, manufactured by Tosoh Corporation.

[0098] <shell> In the above-mentioned modifier (C), the shell is a component that covers the surface of the core and encloses the core (i.e., it is also called the outer shell or coating of the capsule). Examples of materials constituting the shell include resins such as melamine resin, epoxy resin, polyurethane resin, phenolic resin, polyamide resin, polyurea resin, urea resin, and styrene resin, or copolymer resins of two or more of these, alginates, gelatin, gum arabic, and various polymer compounds such as starch. These materials constituting the shell may be used individually or in combination of two or more. In particular, the shell preferably contains one or more selected from the group consisting of melamine resin, polyurea resin, and gelatin, and more preferably contains melamine resin because it does not react well with the core material and the other components contained in the thermosetting resin composition of this disclosure, regardless of the type of core material contained within or the other components, and even more preferably is substantially composed of melamine resin.

[0099] The above-mentioned shell can be destroyed by applying an external load to the resin composition in which the modifier (C) is dispersed. Examples of external loads that can destroy the shell include heat, light, and physical impact (e.g., pressure). In particular, it is preferable that the shell of the modifier (C) is ruptured (the capsule is broken) by heat or pressure.

[0100] The temperature at which the shell ruptures can be appropriately set depending on the type of core material enclosed by the shell. The temperature is preferably 80°C or higher, more preferably 90°C to 200°C, and even more preferably 100°C to 170°C.

[0101] The mass ratio of the shell to the total amount of the above-mentioned modifier (C) is preferably 0.05 to 0.5, and more preferably 0.1 to 0.4, per 1 unit of core mass. By setting the mass ratio of core to shell within the above range, it is possible to achieve both the stability of the modifier (C) properties in the thermosetting resin composition and the ease of breaking the shell of the above-mentioned modifier (C) and the improvement of the physical properties of the cured product due to the diffused modified resin (c).

[0102] The above shells can be formed using known encapsulation methods such as chemical methods (interfacial polymerization, in situ polymerization, orifice method), physicochemical methods (coacervation method), and mechanical / physical methods (air suspension coating method, spray drying method, high-speed airflow impact method).

[0103] The average particle size of the above-mentioned modifier (C) is not particularly limited, but from the viewpoint of achieving both the stability of the modifier (C) properties in the thermosetting resin composition and the ease with which the modifier (C) can be broken down by external loads, as well as the improvement of the physical properties of the cured product by the diffused modified resin (c), it is preferably 1 μm to 300 μm, more preferably 3 μm to 100 μm, and even more preferably 10 μm to 50 μm. The average particle size of the above-mentioned modifier (C) is determined by arbitrarily extracting 100 particles, photographing them using a scanning electron microscope, measuring their particle size, and taking the average value.

[0104] The content of the above-mentioned modifier (C) may be such that it is possible to set the proportion of the modified resin (c) in the above-mentioned thermosetting resin composition to a desired range. For example, it may be 6% by mass or more, more preferably 10% by mass or more, preferably 50% by mass or less, and more preferably 40% by mass or less, in the nonvolatile content of the components of the above-mentioned thermosetting resin composition excluding the filler (D). Furthermore, the content of the above-mentioned modified resin (c) may be such that it is preferably 5% by mass or more, more preferably 8% by mass or more, preferably 40% by mass or less, and more preferably 35% by mass or less, in the nonvolatile content of the components of the above-mentioned thermosetting resin composition excluding the filler (D).

[0105] The above-mentioned modifier (C) can be manufactured using known methods for manufacturing microcapsules, and the manufacturing method is not particularly limited. Examples of the manufacturing method include those described in "Making and Using Microcapsules" (Masumi Koishi et al., Kogyo Chosakai, published in 2005), Japanese Patent Publication No. 2008-63575, Japanese Patent Publication No. 2006-249326, Japanese Patent Publication No. 11-216354, Japanese Patent Publication No. 5-222672, Japanese Patent Publication No. 53-84881, Japanese Patent Publication No. 2000-15087, Japanese Patent Publication No. 2019-002017, etc. More specifically, examples include a method of obtaining a microcapsule slurry by dispersing a core material such as a modified resin (c) in water to obtain an emulsion, and then adding a cell material to this emulsion and stirring; and a method of obtaining a microcapsule slurry by mixing a monomer that will become the resin of the cell material and the core material in water to prepare a mixture, then emulsifying the mixture and adding a solvent and stirring.

[0106] The filler (D) is an essential component for reducing the thermal expansion of the insulating layer to a predetermined basic level, and is preferably one or more selected from the group consisting of inorganic fine particles and fibers. Examples of the inorganic fine particles include silica (fused silica, crystalline silica, etc.), silicon nitride, alumina, clay minerals (talc, clay, etc.), mica powder, aluminum hydroxide, magnesium hydroxide, magnesium oxide, aluminum titanate, barium titanate, calcium titanate, titanium oxide, etc., with silica being preferred and fused silica being more preferred. The shape of the silica may be either crushed or spherical, but it is preferable to be spherical from the viewpoint of suppressing the melt viscosity of the thermosetting resin composition while increasing the amount of silica added.

[0107] The volume-average particle diameter of the above inorganic fine particles is, for example, 0.01 μm or more, more preferably 0.03 μm or more, preferably 100 μm or less, more preferably 80 μm or less, and even more preferably 50 μm or less. The volume-average particle diameter of the above inorganic fine particles can be measured by laser diffraction.

[0108] Examples of the above fibers include inorganic fibers such as glass fibers and carbon fibers, and organic fibers may also be used. The inorganic fibers may be long fibers or short fibers. The carbon fibers may be either polyacrylonitrile-based or pitch-based. The diameter of the inorganic fibers is, for example, 1 μm or more, preferably 3 μm or more, for example 30 μm or less, preferably 20 μm or less, and more preferably 15 μm or less.

[0109] Furthermore, the fibers may be dispersed in a thermosetting resin composition, arranged in a single direction, or formed into a woven or nonwoven fabric. The thickness of the woven or nonwoven fabric is preferably 100 μm or less, preferably 2 μm or more, and more preferably 5 μm or more.

[0110] The content of the above-mentioned filler (D) is 40% by mass or more, preferably 60% by mass or more, preferably 99% by mass or less, and more preferably 95% by mass or less, based on the nonvolatile content of the thermosetting composition.

[0111] The thermosetting resin composition of this disclosure contains the above components (A) to (D) as essential components, but curing accelerators, other additives, etc. may be used as needed.

[0112] The curing accelerator can be appropriately selected depending on the type of curing agent (B). Specific examples of curing accelerators include phosphorus compounds, tertiary amines, imidazole compounds, organic acid metal salts, Lewis acids, and amine complex salts. When the thermosetting resin composition contains a curing accelerator, the content of the curing accelerator is, for example, 0.005% by mass or more and 5% by mass or less of the non-volatile content of the components of the thermosetting resin composition excluding the filler (D).

[0113] Other additives that can be used include, for example, flame retardants, organic solvents, conductive particles, rubber, fillers, silane coupling agents, mold release agents, pigments, emulsifiers, and the like.

[0114] The thermosetting resin composition of this disclosure can be obtained by mixing the above components and can be cured by thermosetting. Examples of the shape of the cured product include laminates, cast products, adhesive layers, coatings, films, etc.

[0115] Applications of the thermosetting resin composition disclosed herein include semiconductor encapsulation materials, printed circuit board materials, resin casting materials, adhesives, interlayer insulating materials for build-up substrates, and build-up adhesive films. Among these applications, the insulating materials for printed circuit boards and electronic circuit boards, and the build-up adhesive films, can be used as insulating materials for so-called electronic component embedded substrates, in which passive components such as capacitors and active components such as IC chips are embedded within the substrate. Among these, its properties such as high heat resistance, low thermal expansion, low viscosity, low elastic modulus, and solvent solubility make it preferable to use as a printed circuit board material or a build-up adhesive film.

[0116] A method for preparing a semiconductor encapsulating material from the thermosetting composition of this disclosure is to thoroughly melt and mix the thermosetting resin composition until it becomes uniform, for example, using an extruder, needle, roll, etc.

[0117] When the thermosetting resin composition of this disclosure is used as a semiconductor encapsulation material, a semiconductor package can be formed. Specifically, the composition can be molded using a casting mold, a transfer molding machine, an injection molding machine, etc., and then heated at 50 to 200°C for 2 to 10 hours to obtain a molded semiconductor device.

[0118] Furthermore, a method for manufacturing a printed circuit board using the thermosetting resin composition of this disclosure involves impregnating a reinforcing substrate with the thermosetting resin composition, layering copper foil on top, and then heating and pressing the substrates together. Examples of the reinforcing substrates include paper, glass cloth, glass nonwoven fabric, aramid paper, aramid cloth, glass mat, and glass roving cloth. More specifically, first, the thermosetting resin composition can be heated (preferably to 50-170°C depending on the type of organic solvent (F)) to obtain a cured prepreg. The resin content in the prepreg is preferably 20% by mass or more and 60% by mass or less. Next, the prepregs are laminated, copper foil is layered on top, and the substrates are heated and pressed together at 170-300°C under pressure of 1-10 MPa for 10 minutes to 3 hours to obtain the desired printed circuit board.

[0119] When the thermosetting resin composition of this disclosure is used as a conductive paste, examples include dispersing conductive particles (fine conductive particles) in the thermosetting resin composition to create a composition for an anisotropic conductive film, or creating a paste resin composition for circuit connection or an anisotropic conductive adhesive that is liquid at room temperature.

[0120] A method for obtaining an interlayer insulating material for a build-up substrate from the thermosetting resin composition of this disclosure involves, for example, applying the thermosetting resin composition to a wiring board with a circuit formed on it using a spray coating method, a curtain coating method, or the like, and then curing it. After that, if necessary, holes such as predetermined through-holes are drilled, the surface is treated with a roughening agent, and the surface is washed with hot water to form irregularities, and then plated with a metal such as copper. Electroless plating and electrolytic plating are preferred as the plating method, and examples of roughening agents include oxidizing agents, alkalis, and organic solvents. By sequentially repeating these operations as desired, a build-up substrate can be obtained by alternately building up a resin insulating layer and a conductor layer of a predetermined circuit pattern. However, drilling the through-holes is performed after the formation of the outermost resin insulating layer. Alternatively, a resin-coated copper foil, with the thermosetting resin composition partially cured on copper foil, can be heated and pressed onto a wiring board with a circuit formed on it at 170-300°C to form a roughened surface, thus omitting the plating process and producing a build-up substrate.

[0121] A method for producing a build-up film from the thermosetting resin composition of this disclosure includes, for example, a method of applying the thermosetting resin composition of this disclosure onto a support film to form a resin composition layer and thereby producing a build-up film for a multilayer printed circuit board.

[0122] When the thermosetting resin composition of this disclosure is used in a build-up film, it is essential that the film softens under the lamination temperature conditions in the vacuum lamination method (usually 70°C to 140°C) and exhibits fluidity (resin flow) that allows for simultaneous lamination of the circuit board and resin filling of via holes or through holes present in the circuit board. It is preferable to formulate the above components in such a way as to exhibit these characteristics.

[0123] Here, the diameter of the through-holes in a multilayer printed circuit board is typically 0.1 to 0.5 mm, and the depth is typically 0.1 to 1.2 mm. It is generally preferable to be able to fill the holes with resin within this range. When laminating both sides of the circuit board, it is desirable to fill about half of the through-holes.

[0124] The adhesive film described above can be manufactured by first preparing a varnish-like thermosetting resin composition of the present disclosure, then applying this varnish-like composition to the surface of a support film (Y), and finally drying the organic solvent by heating or blowing hot air to form a layer (X) of the thermosetting composition.

[0125] The thickness of the formed layer (X) is usually greater than or equal to the thickness of the conductor layer. Since the thickness of the conductor layer of a circuit board is usually in the range of 5 to 70 μm, it is preferable that the thickness of the resin composition layer be 10 to 100 μm.

[0126] The layer (X) in this disclosure may be protected by a protective film as described later. Protecting it with a protective film prevents dirt and other debris from adhering to the surface of the resin composition layer and prevents scratches.

[0127] The support film and protective film mentioned above can be made of polyolefins such as polyethylene, polypropylene, and polyvinyl chloride, polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate, polycarbonate, polyimide, and also release paper and metal foils such as copper foil and aluminum foil. In addition, the support film and protective film may be treated with a mat treatment, corona treatment, or release treatment.

[0128] The thickness of the support film is not particularly limited, but is usually 10 to 150 μm, and preferably in the range of 25 to 50 μm. The thickness of the protective film is preferably 1 to 40 μm.

[0129] The support film (Y) described above is peeled off after lamination to the circuit board or after an insulating layer is formed by heat curing. Peeling off the support film (Y) after heat curing the adhesive film prevents the adhesion of dust and other debris during the curing process. When peeling off after curing, the support film is usually treated with a release agent beforehand.

[0130] Next, a method for manufacturing a multilayer printed wiring board using the adhesive film obtained as described above is, for example, when layer (X) is protected by a protective film, after peeling these, on one or both sides of the circuit board so that layer (X) directly contacts the circuit board, laminate by, for example, a vacuum lamination method. The lamination method may be a batch type or a continuous roll type. Also, before performing lamination, the adhesive film and the circuit board may be heated (preheated) as necessary.

[0131] The lamination conditions are preferably a crimping temperature (lamination temperature) of 70 to 140°C and a crimping pressure of preferably 1 to 11 kgf / cm 2 (9.8×104 to 107.9×104 N / m 2 ), and it is preferable to laminate under a reduced pressure of an air pressure of 20 mmHg (26.7 hPa) or less.

[0132] As a method for obtaining the cured product of the present disclosure, it may conform to the curing method of a general thermosetting resin composition. For example, the heating temperature conditions may be appropriately selected depending on the type and use of the curing agent to be combined, etc., but the composition obtained by the above method may be heated in a temperature range of about 20 to 300°C.

[0133] II. Capsule-shaped modifier The capsule-shaped modifier of the present disclosure has a core and a shell that coats the surface of the core, and the core contains a modified resin (c).

[0134] The capsule-shaped modifier of the present disclosure can be uniformly dispersed together with other solid (powder-like) components such as thermosetting resins and curing agents. Also, when an external load such as heat or pressure is applied to a mixture (thermosetting resin composition) with a powdery material, the shell of the capsule-shaped modifier of the present disclosure easily breaks or disintegrates and opens, and the modified resin can be uniformly dispersed in the composition. Thereby, the capsule-shaped modifier of the present disclosure can improve the physical properties of the cured product of the composition.

[0135] The details of the encapsulated modifier in this disclosure are the same as those of modifier (C) described in section I. Thermosetting resin composition above.

[0136] In the encapsulated modifier of this disclosure, examples of the modified resin include polyester resin, polyurethane resin, polyether resin, polycarbonate resin, acrylic resin, epoxy resin, phenolic resin, rosin-based resin, polyester polyol resin, polyether polyol resin, and polyether ester polyol resin. The details of the various resins are the same as those of the modified resin (c) described in the section "I. Thermosetting Resin Compositions" above, so a detailed explanation is omitted here.

[0137] The modified resin may be a thermoplastic resin or a thermosetting resin, but a thermoplastic resin is preferred. Furthermore, the modified resin preferably has at least one functional group selected from the group consisting of hydroxyl groups and carboxyl groups, and more preferably has one or more hydroxyl groups.

[0138] In particular, in the encapsulated modifier of this disclosure, the modifying resin preferably includes a polyether ester polyol resin and / or a urethane resin made from at least one of a polyether polyol and a polyether ester polyol. The reasons for this and the details of these resins are the same as those for the modifying resin (c) described in the section "I. Thermosetting Resin Composition" above, so the explanation is omitted here.

[0139] In the encapsulated modifier of this disclosure, the ether concentration of the modifying resin is not particularly limited, but is preferably 11.5 mol / kg or more and 23 mol / kg or less. In addition to the effects exhibited by the encapsulation, the encapsulated modifier containing the modifying resin can enhance the effects exhibited by the modifying resin because it contains a modifying resin with a desired ether concentration. Specifically, when a mixture containing a powdered thermosetting resin, a powdered curing agent, and a encapsulated modifier is cured, the modifying resin encapsulated in the encapsulated modifier can more effectively reduce the thermal expansion coefficient and elastic modulus of the cured product of the mixture, thereby improving its physical properties. Furthermore, it can suppress the occurrence of warping. The more preferred range for the ether concentration of the modifying resin is the same as the details of the modifying resin (c) described in the "I. Thermosetting Resin Composition" section above, so the explanation is omitted here.

[0140] In the encapsulated modifier of this disclosure, it is preferable that the shell comprises one or more materials selected from the group consisting of melamine resin, polyurea resin, and gelatin. The reasons for this and the details of these resins are the same as those described in the section "I. Thermosetting Resin Composition" above, and therefore the explanation is omitted here.

[0141] Further details regarding the encapsulated modifier of this disclosure are the same as those for modifier (C) described in section I. Thermosetting Resin Composition above, and therefore are omitted here.

[0142] The encapsulated modifier of this disclosure can be suitably used in the preparation of mixtures containing powdered thermosetting resins and powdered curing agents, and is particularly suitable as an additive to thermosetting resin compositions for semiconductor encapsulants and printed circuit boards. [Examples]

[0143] The present disclosure will be explained in more detail below with reference to examples.

[0144] [Synthesis Example 1] Synthesis of Polyether Ester Polyol 1 In a reaction apparatus, 925.0 parts by mass of bifunctional polypropylene glycol with a number average molecular weight of 1000 (trademark; manufactured by AGC Inc., "EXCENOL1020"), 57.5 parts by mass of isophthalic acid (hereinafter referred to as "iPA"), and 17.5 parts by mass of sebacic acid (hereinafter referred to as "SebA") were charged, and heating and stirring were started while blowing in nitrogen gas. Next, after raising the internal temperature to 220°C, 0.10 parts by mass of tetraisopropyl titanate (hereinafter referred to as "TiPT") was charged, and the reaction was carried out at 220°C for 24 hours to synthesize polyether ester polyol 1. The obtained polyether ester polyol 1 had an acid value of 0.2, a hydroxyl value of 56.3, a number average molecular weight of 1986, an ether concentration of 14.9 mol / kg, a viscosity of 820 mPa·s at 25°C, and a viscosity of 20 mPa·s at 150°C.

[0145] [Synthesis Example 2] Synthesis of Polyether Ester Polyol 2 In a reaction apparatus, 881.1 parts by mass of EXCENOL1020, 91.2 parts by mass of iPA, and 27.7 parts by mass of SebA were charged, and heating and stirring were started while blowing in nitrogen gas. Next, after raising the internal temperature to 220°C, 0.10 parts by mass of TiPT were charged, and the reaction was carried out at 220°C for 40 hours to synthesize polyether ester polyol 2. The resulting polyether ester polyol 2 had an acid value of 0.7, a hydroxyl value of 24.5, an ether concentration of 14.4 mol / kg, a number-average molecular weight of 4453, a viscosity of 5580 mPa·s at 25°C, and a viscosity of 65 mPa·s at 150°C.

[0146] [Synthesis Example 3] Synthesis of Polyurethane Polyol 1 In a reactor purged with nitrogen gas, 500.0 parts by mass of polyether ester polyol 2 synthesized in Synthesis Example 2 and 21.2 parts by mass of 4,4'-diphenylmethane diisocyanate (hereinafter referred to as "MDI") were charged, and heating and stirring were started under a nitrogen atmosphere. Then, polyurethane polyol 1 was synthesized by reacting at an internal temperature of 100°C for 5 hours. The obtained polyurethane polyol 1 had an acid value of 0.6, a hydroxyl value of 5.2, an ether concentration of 13.8 mol / kg, a number-average molecular weight of 19350, a viscosity of 450000 mPa·s at 25°C, and a viscosity of 2840 mPa·s at 150°C.

[0147] [Synthesis Example 4] Preparation of a mixture of polyether ester polyol 1 and polyurethane polyol 1 750 parts by mass of polypolyether ester polyol 1 synthesized in Synthesis Example 1 and 250 parts by mass of polyurethane polyol 1 synthesized in Synthesis Example 3 were charged into a reaction apparatus, and heating and stirring were started under a nitrogen atmosphere. Then, the mixture was stirred and mixed at 90°C for 30 minutes to obtain a mixture 1 of polyether ester polyol 1 and polyurethane polyol 1. The resulting mixture 1 had an acid value of 0.3, a hydroxyl value of 43.4, an ether concentration of 14.7 mol / kg, a number-average molecular weight of 2570, a viscosity of 5000 mPa·s at 25°C, and a viscosity of 70 mPa·s at 150°C.

[0148] [Synthesis Example 5] Synthesis of Polyurethane Polyol 2 In a reactor purged with nitrogen gas, 941.2 parts by mass of bifunctional polypropylene glycol (trademark; manufactured by AGC Inc., 'EXCENOL2020') with a number average molecular weight of 2000 and 58.8 parts by mass of MDI were charged, and heating and stirring were started under a nitrogen atmosphere. Then, the reaction was carried out at an internal temperature of 90°C for 2 hours to synthesize polyurethane polyol 2. The obtained polyurethane polyol 2 had an acid value of 0, a hydroxyl value of 26.4, an ether concentration of 15.6 mol / kg, a number average molecular weight of 4250, a viscosity of 4900 mPa·s at 25°C, and a viscosity of 60 mPa·s at 150°C.

[0149] [Synthesis Example 6] Synthesis of Polyether Ester Polyol 3 876.1 parts by mass of an 8-mol adduct of bisphenol A to propylene oxide and 123.9 parts by mass of SebA were charged into the reaction apparatus, and heating and stirring were started while blowing in nitrogen gas. Next, after raising the internal temperature to 220°C, 0.10 parts by mass of tetraisopropyl titanate (hereinafter referred to as "TiPT") was charged, and the reaction was carried out at 220°C for 24 hours to synthesize polyether ester polyol 3. The obtained polyether ester polyol 3 had an acid value of 0.1, a hydroxyl value of 75.2, a number-average molecular weight of 1,490, an ether concentration of 10.3 mol / kg, a viscosity of 12,500 mPa·s at 25°C, and a viscosity of 32 mPa·s at 150°C.

[0150] [Synthesis Example 7] Production of Microcapsule 1 100 parts by mass of isobutylene-maleic anhydride copolymer (Isoban 04, manufactured by Kuraray Co., Ltd.) and 10.4 parts by mass of sodium hydroxide were added to 625.6 parts by mass of ion-exchanged water, and the mixture was stirred in a pressurized vessel at 110°C for 4 hours to obtain an aqueous solution with a pH of 2.9. Next, 100 parts by mass of this aqueous solution was added to 270 parts by mass of ion-exchanged water, and then 150 parts by mass of polyether ester polyol 1 synthesized in Synthesis Example 1 was added as the core material (core substance) of the capsules. This mixture was then stirred at room temperature using a homogenizer to prepare an aqueous dispersion. Next, 110 parts by mass of ion-exchanged water and 65 parts by mass of methylol melamine initial polymer (Amidia M-3, manufactured by DIC Corporation, 77% non-volatile content) as the shell material (wall material) of the microcapsules were added to the above aqueous dispersion, and the mixture was heated to 90°C and polycondensed while stirring for 2 to 3 hours to obtain a microcapsule slurry. Next, the slurry of the microcapsules was dehydrated using a centrifugal dehydrator, and then dried to obtain an aggregate of microcapsules (microcapsule 1). The average particle size of the obtained microcapsule 1 was 10 μm, and the mass ratio of core (non-volatile content) to shell (non-volatile content) (core:shell) was 3:1.

[0151] [Synthesis Example 8] Production of Microcapsule 2 Microcapsule aggregates (microcapsules 2) were manufactured in the same manner as in Synthesis Example 7, except that mixture 1 prepared in Synthesis Example 4 was used as the core material (core substance) of the capsules instead of polyether ester polyol 1. The average particle size of microcapsules 2 was 10 μm, and the mass ratio (core:shell) of core (non-volatile content) to shell (non-volatile content) was 3:1.

[0152] [Synthesis Example 9] Production of Microcapsule 3 Microcapsule aggregates (microcapsules 3) were manufactured in the same manner as in Synthesis Example 7, except that polyether ester polyol 2 was used instead of polyether ester polyol 1 as the core material (core substance) of the capsules. The average particle size of microcapsules 3 was 10 μm, and the mass ratio (core:shell) of core (non-volatile content) to shell (non-volatile content) was 3:1.

[0153] [Synthesis Example 10] Manufacturing of Microcapsule 4 Microcapsule aggregates (microcapsules 4) were manufactured in the same manner as in Synthesis Example 7, except that polyurethane polyol 2 was used instead of polyether ester polyol 1 as the core material (core substance) of the capsules. The average particle size of microcapsules 4 was 20 μm, and the mass ratio (core:shell) of core (non-volatile content) to shell (non-volatile content) was 3:1.

[0154] [Synthesis Example 11] Manufacturing of Microcapsule 5 Microcapsule aggregates (microcapsules 5) were manufactured in the same manner as in Synthesis Example 7, except that polyether ester polyol 3 was used instead of polyether ester polyol 1 as the core material (core substance) of the capsules. The average particle size of microcapsules 5 was 30 μm, and the mass ratio (core:shell) of core (non-volatile content) to shell (non-volatile content) was 3:1.

[0155] [Example 1] 6.82 parts by mass of solid epoxy resin 1 ("EPICLON HP-4700" manufactured by DIC Corporation), 2.27 parts by mass of solid epoxy resin 2 ("YX-4000H" manufactured by Mitsubishi Chemical Corporation), and 5.51 parts by mass of novolac-type phenolic resin curing agent ("PHENOLITE TD-2131" manufactured by DIC Corporation) were each pulverized into powder and placed in a Henschel mixer. Next, 5.4 parts by mass of microcapsules 1, 1 part by mass of triphenylphosphine, 40 parts by mass of fused silica 1 ("FB-5SDC" manufactured by Denka Co., Ltd.), and 40 parts by mass of fused silica 2 ("FB-5604FC" manufactured by Denka Co., Ltd.) were added and then uniformly mixed to obtain thermosetting resin composition 1.

[0156] [Example 2] A thermosetting resin composition 2 was obtained in the same manner as in Example 1, except that microcapsule 1 was replaced with microcapsule 2.

[0157] [Example 3] A thermosetting resin composition 3 was obtained in the same manner as in Example 1, except that the above-mentioned microcapsule 1 was replaced with microcapsule 3.

[0158] [Example 4] A thermosetting resin composition 4 was obtained in the same manner as in Example 1, except that the above-mentioned microcapsule 1 was replaced with microcapsule 4.

[0159] [Example 5] Thermosetting resin composition 5 was obtained in the same manner as in Example 1, except that the amount of solid epoxy resin 1 used was changed from 6.82 parts by mass to 7.48 parts by mass, the amount of solid epoxy resin 2 used was changed from 2.27 parts by mass to 2.49 parts by mass, the amount of novolac-type phenolic resin curing agent used was changed from 5.51 parts by mass to 6.03 parts by mass, and the amount of microcapsule 1 used was changed from 5.4 parts by mass to 4 parts by mass.

[0160] [Example 6] Thermosetting resin composition 6 was obtained in the same manner as in Example 1, except that the amount of solid epoxy resin 1 used was changed from 6.82 parts by mass to 6.07 parts by mass, the amount of solid epoxy resin 2 used was changed from 2.27 parts by mass to 2.03 parts by mass, the amount of novolac-type phenolic resin curing agent used was changed from 5.51 parts by mass to 4.9 parts by mass, and the amount of microcapsule 1 used was changed from 5.4 parts by mass to 7 parts by mass.

[0161] [Example 7] A thermosetting resin composition 7 was obtained in the same manner as in Example 6, except that microcapsule 1 was replaced with microcapsule 5.

[0162] [Comparative Example 1] Thermosetting resin composition 1' was obtained in the same manner as in Example 1, except that the amount of solid epoxy resin 1 used was changed from 6.82 parts by mass to 9.34 parts by mass, the amount of solid epoxy resin 2 used was changed from 2.27 parts by mass to 3.12 parts by mass, the amount of novolac-type phenolic resin curing agent used was changed from 5.51 parts by mass to 7.54 parts by mass, and the amount of microcapsule 1 used was changed from 5.4 parts by mass to 0 parts by mass.

[0163] [Comparative Example 2] Thermosetting resin composition 2' was obtained in the same manner as in Example 1, except that the above microcapsule 1 was replaced with polyether ester polyol 1, which is the modified resin (c) before encapsulation, and the amount of polyether ester polyol 1 used was the same as the blending ratio of polyether ester polyol 1 contained in the above microcapsule 1 in Example 1 (the content ratio of polyether ester polyol 1 in the nonvolatile content of the thermosetting resin composition excluding fused silica 1 and 2).

[0164] <Rating> [Uniform dispersibility] The uniform dispersion of microcapsules in the thermosetting resin compositions obtained in the examples and comparative examples (in Comparative Example 2, the core material (polyester polyol 1) was not encapsulated) was visually confirmed. "〇": Almost no clumps or unevenness, evenly distributed. "×": Clumps, unevenness, and inconsistent dispersion.

[0165] [Thermal expansion coefficient after curing of thermosetting resin composition (evaluation of thermal expansion)] The thermosetting resin compositions obtained in the examples and comparative examples were kneaded in a twin-screw extruder heated to 130°C, and then thermoset at 175°C for 5 hours. Using a TMA6200 (Seiko Instruments Corporation) as a thermal analyzer, the linear thermal expansion coefficient in the range of 40 to 60°C was measured at a heating rate of 3°C / min. "〇": Less than 12.5 ppm / ℃ "△": 12.5 ppm / ℃ or higher, less than 13.5 ppm / ℃ "×": 13.5 ppm / ℃ or higher

[0166] [Equilibrium modulus of thermosetting resin composition after curing (evaluation of elastic modulus)] The thermosetting resin compositions obtained in the examples and comparative examples were kneaded in a twin-screw extruder heated to 130°C, and then heat-cured at 175°C for 5 hours. After that, the flexural modulus was measured in accordance with JIS K7171. "〇": Less than 16000MPa "×": 16000MPa or higher

[0167] [Table 1]

[0168] [Table 2]

[0169] The thermosetting resin composition of the present invention was found to exhibit excellent uniform dispersibility, low thermal expansion, and low modulus of elasticity. On the other hand, the thermosetting resin composition of Comparative Example 1, which did not contain modifier (C), exhibited poor low thermal expansion and low modulus of elasticity. Furthermore, the thermosetting resin composition of Comparative Example 2, which used an unencapsulated polyether ester polyol as modifier (C) (a form containing only modifier resin (c)), exhibited poor uniform dispersibility due to clumping and unevenness within the thermosetting resin composition, resulting in variations in physical properties after curing.

Claims

1. A thermosetting composition comprising a thermosetting resin (A), a curing agent (B), a modifier (C), and one or more fillers (D) selected from the group consisting of inorganic fine particles and fibers, The modifier (C) has a capsule structure comprising a core and a shell covering the surface of the core, wherein the core contains a modified resin (c), A thermosetting resin composition in which the modified resin (c) includes a polyether ester polyol resin and / or a urethane resin made from at least one of a polyether polyol and a polyether ester polyol.

2. The thermosetting resin composition according to claim 1, wherein the modified resin (c) has an ether concentration of 11.5 mol / kg or more and 23 mol / kg or less.

3. The thermosetting resin composition according to claim 1, wherein the modified resin (c) has at least one functional group selected from the group consisting of hydroxyl groups and carboxyl groups.

4. The thermosetting resin composition according to claim 1, wherein the number average molecular weight of the modified resin (c) is 500 or more and 20,000 or less.

5. The thermosetting resin composition according to claim 1, wherein the shell comprises one or more selected from the group consisting of melamine resin, polyurea resin, and gelatin.

6. The thermosetting resin composition according to claim 1, wherein the content of the modified resin (c) is 5% by mass or more and 45% by mass or less of the nonvolatile content of the components obtained by removing the filler (D) from the thermosetting resin composition.

7. A cured product of the thermosetting resin composition according to claim 1.

8. A semiconductor encapsulant comprising the thermosetting resin composition described in claim 1.

9. A semiconductor device comprising the semiconductor encapsulant described in claim 8.

10. An insulating material for printed circuit boards comprising the thermosetting resin composition described in claim 1.

11. A printed circuit board comprising the insulating material for printed circuit boards according to claim 10.

12. It has a core and a shell covering the surface of the core, and the core contains a modified resin. The modified resin is a encapsulated modifier comprising a polyether ester polyol resin and / or a urethane resin made from at least one of a polyether polyol and a polyether ester polyol.

13. The encapsulated modifier according to claim 12, wherein the ether concentration of the modified resin is 11.5 mol / kg or more and 23 mol / kg or less.

14. The encapsulated modifier according to claim 12, wherein the modified resin has at least one functional group selected from the group consisting of hydroxyl groups and carboxyl groups.

15. The encapsulated modifier according to claim 12, wherein the shell comprises one or more selected from the group consisting of melamine resin, polyurea resin, and gelatin.

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