Thermosetting epoxy resin composition

Abstract

To provide a thermosetting epoxy resin composition that allows a resin composition to gelate in a shortened time, and has a shortened curing process for improved production efficiency, and can suppress volatilization of a monomer component such as an acid anhydride curing agent.SOLUTION: A thermosetting epoxy resin composition contains an alicyclic epoxy compound (A), an acid anhydride curing agent (B), a heat cation curing catalyst (C), and at least one compound selected from the group consisting of an organic acid metal salt and a metal chelate compound as a curing accelerator (D).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a thermosetting epoxy resin composition, a cured product of the thermosetting epoxy resin composition, and an optical semiconductor device in which an optical semiconductor element is encapsulated with the cured product of the thermosetting epoxy resin composition. [Background technology]

[0002] In recent years, the output of optical semiconductor devices has been increasing, and resins (encapsulants) that cover optical semiconductor elements in such optical semiconductor devices are required to have high heat resistance, light resistance, crack resistance, and the like. Conventionally, as an encapsulant for forming an encapsulant having high heat resistance, light resistance, and crack resistance, for example, a thermosetting composition containing an alicyclic epoxy compound, monoallyl diglycidyl isocyanurate, an acid anhydride curing agent, and a curing accelerator has been known (see, for example, Patent Document 1, etc.). However, the above-mentioned thermosetting composition has a problem that it takes a long time to cure, which lengthens the time of the manufacturing process and reduces the production efficiency. In addition, there is also a problem that monomer components such as the acid anhydride curing agent volatilize during heat curing, resulting in a decrease in the amount of resin that was initially poured. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-209524 A Summary of the Invention [Problem to be solved by the invention]

[0004] Therefore, an object of the present invention is to provide a thermosetting epoxy resin composition which can shorten the gelation time of the resin composition, shorten the curing process, improve production efficiency, and suppress volatilization of monomer components such as an acid anhydride curing agent. Another object of the present invention is to provide a cured product of the above thermosetting epoxy resin composition. Another object of the present invention is to provide an optical semiconductor device in which an optical semiconductor element is encapsulated with a cured product of the above thermosetting epoxy resin composition. [Means for solving the problem]

[0005] As a result of intensive research to solve the above problems, the present inventors have found that a thermosetting epoxy resin composition containing an alicyclic epoxy compound, an acid anhydride curing agent, a thermal cationic curing catalyst, and at least one compound selected from the group consisting of organic acid metal salts and metal chelate compounds as a curing accelerator can shorten the gelation time of the resin, shorten the curing process, and improve production efficiency. They also found that the shortened time to gelation can suppress the amount of volatilization of monomer components such as the acid anhydride curing agent, and thus completed the present invention.

[0006] That is, the present invention provides a thermosetting epoxy resin composition comprising an alicyclic epoxy compound (A), an acid anhydride curing agent (B), a thermal cationic curing catalyst (C), and one or more compounds (D) selected from the group consisting of organic acid metal salts and metal chelate compounds as a curing accelerator.

[0007] The curing reaction initiation temperature of the thermosetting epoxy resin composition is preferably 150° C. or lower.

[0008] In the thermosetting epoxy resin composition, the content of the acid anhydride curing agent (B) may be an amount of 0.01 to 1.0 equivalent relative to 1 equivalent of epoxy groups in all compounds having epoxy groups contained in the thermosetting epoxy resin composition.

[0009] In the thermosetting epoxy resin composition, the alicyclic epoxy compound (A) may be a compound having a cyclohexene oxide group.

[0010] In the thermosetting epoxy resin composition, the alicyclic epoxy compound (A) is represented by the following formula (I-1): [ka] The compound may be represented by the formula:

[0011] The thermosetting epoxy resin composition may further contain an antioxidant (E).

[0012] The thermosetting epoxy resin composition further comprises a compound represented by the following formula (1): [ka] [In the formula, R 1 , R 2 are the same or different and represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. The monoallyl diglycidyl isocyanurate compound (F) represented by the following formula:

[0013] The thermosetting epoxy resin composition may further contain a siloxane derivative having two or more epoxy groups in the molecule.

[0014] The thermosetting epoxy resin composition may further contain an alicyclic polyester resin.

[0015] The present invention also provides a cured product of the thermosetting epoxy resin composition.

[0016] The thermosetting epoxy resin composition may be an optical semiconductor encapsulating resin composition.

[0017] The present invention also provides an optical semiconductor device in which an optical semiconductor element is encapsulated with a cured product of the optical semiconductor encapsulating resin composition. Effect of the Invention

[0018] Since the thermosetting epoxy resin composition of the present invention has the above-mentioned configuration, the gelation time of the resin composition is shortened, and the curing process is shortened, thereby improving the production efficiency. In addition, as a result of the shortened time until gelation, the volatilization of monomer components such as acid anhydride curing agents can be suppressed. Therefore, a cured product having high heat resistance, light resistance, and crack resistance can be efficiently formed. Therefore, by using the thermosetting epoxy resin composition of the present invention as a resin composition for sealing optical semiconductors, optical semiconductor devices having high quality can be efficiently manufactured. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] <Thermosetting epoxy resin composition> The thermosetting epoxy resin composition of the present invention is a thermosetting resin composition containing at least an alicyclic epoxy compound (A), an acid anhydride curing agent (B), a thermal cationic curing catalyst (C), and one or more compounds (D) selected from the group consisting of organic acid metal salts and metal chelate compounds as a curing accelerator.

[0020] [Alicyclic epoxy compound (A)] The alicyclic epoxy compound (A) in the thermosetting epoxy resin composition of the present invention is a compound having at least an alicyclic (aliphatic ring) structure and an epoxy group in a molecule (in one molecule). Specific examples of the alicyclic epoxy compound (A) include (i) a compound having an epoxy group (alicyclic epoxy group) composed of two adjacent carbon atoms and an oxygen atom constituting an alicyclic ring, and (ii) a compound in which an epoxy group is directly bonded to an alicyclic ring by a single bond. However, the alicyclic epoxy compound (A) does not include a siloxane derivative having two or more epoxy groups in a molecule, which will be described later.

[0021] The above-mentioned (i) compound having an epoxy group (alicyclic epoxy group) composed of two adjacent carbon atoms and an oxygen atom constituting an alicyclic ring can be arbitrarily selected from known or commonly used compounds. Among them, the alicyclic epoxy group is preferably a cyclohexene oxide group.

[0022] As the above-mentioned (i) compound having an epoxy group composed of two adjacent carbon atoms and an oxygen atom constituting an alicyclic ring, from the viewpoints of transparency and heat resistance, a compound having a cyclohexene oxide group is preferred, and a compound represented by the following formula (I) (alicyclic epoxy compound) is particularly preferred. [ka]

[0023] In the above formula (I), X represents a single bond or a linking group (a divalent group having one or more atoms). Examples of the linking group include a divalent hydrocarbon group, a carbonyl group, an ether bond, an ester bond, a carbonate group, an amide group, and groups in which a plurality of these groups are linked together.

[0024] An example of the alicyclic epoxy compound in which X in the above formula (I) is a single bond is (3,4,3',4'-diepoxy)bicyclohexyl.

[0025] Examples of the divalent hydrocarbon group include linear or branched alkylene groups having 1 to 18 carbon atoms, and divalent alicyclic hydrocarbon groups. Examples of the linear or branched alkylene groups having 1 to 18 carbon atoms include methylene, methylmethylene, dimethylmethylene, ethylene, propylene, and trimethylene. Examples of the divalent alicyclic hydrocarbon group include divalent cycloalkylene groups (including cycloalkylidene groups) such as 1,2-cyclopentylene, 1,3-cyclopentylene, cyclopentylidene, 1,2-cyclohexylene, 1,3-cyclohexylene, 1,4-cyclohexylene, and cyclohexylidene.

[0026] As the linking group X, in particular, a linking group containing an oxygen atom is preferable, and specific examples thereof include -CO-, -O-CO-O-, -COO-, -O-, -CONH-, a group in which a plurality of these groups are linked together, a group in which one or more of these groups are linked to one or more divalent hydrocarbon groups, etc. Examples of the divalent hydrocarbon group include those exemplified above.

[0027] Representative examples of the alicyclic epoxy compound represented by the above formula (I) include compounds represented by the following formulas (I-1) to (I-10). In the following formulas (I-5) and (I-7), l and m each represent an integer of 1 to 30. In the following formula (I-5), R is an alkylene group having 1 to 8 carbon atoms, and examples of such alkylene groups include linear or branched alkylene groups such as methylene, ethylene, propylene, isopropylene, butylene, isobutylene, s-butylene, pentylene, hexylene, heptylene, and octylene. Among these, linear or branched alkylene groups having 1 to 3 carbon atoms such as methylene, ethylene, propylene, and isopropylene are preferred. In the following formulas (I-9) and (I-10), n1 to n6 each represent an integer of 1 to 30. [ka] [ka]

[0028] An example of the above-mentioned (ii) compound in which an epoxy group is directly bonded to an alicyclic ring via a single bond is a compound represented by the following formula (II). [ka]

[0029] In formula (II), R' is a group obtained by removing p -OH from a p-hydric alcohol, and p and n are natural numbers. pExamples of the compound include polyhydric alcohols such as 2,2-bis(hydroxymethyl)-1-butanol (alcohols having 1 to 15 carbon atoms). p is preferably 1 to 6, and n is preferably 1 to 30. When p is 2 or more, n in each group in ( ) (parentheses) may be the same or different. Specific examples of the compound include 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol, trade name "EHPE3150" (manufactured by Daicel Corporation).

[0030] In the thermosetting epoxy resin composition of the present invention, the alicyclic epoxy compound (A) may be used alone or in combination of two or more. In addition, as the alicyclic epoxy compound (A), for example, commercially available products such as "Celloxide 2021P" and "Celloxide 2081" (both manufactured by Daicel Corporation) may also be used.

[0031] As the alicyclic epoxy compound (A), 3,4-epoxycyclohexylmethyl(3,4-epoxy)cyclohexanecarboxylate represented by the above formula (I-1), trade name "Celloxide 2021P" (manufactured by Daicel Corporation), is particularly preferred.

[0032] The content (blended amount) of the alicyclic epoxy compound (A) in the thermosetting epoxy resin composition of the present invention is not particularly limited, but is preferably 5 to 90% by weight, more preferably 10 to 80% by weight, and further preferably 15 to 70% by weight, based on the thermosetting epoxy resin composition (100% by weight).

[0033] The content (mixture amount) of the alicyclic epoxy compound (A) relative to the total amount of compounds having an epoxy group (total epoxy compounds) (100% by weight) contained in the thermosetting epoxy resin composition is not particularly limited, but is preferably 10 to 95% by weight, more preferably 20 to 90% by weight, and further preferably 30 to 80% by weight. If the content of the alicyclic epoxy compound (A) is less than 20% by weight, the heat resistance, light resistance, thermal shock resistance, and moisture absorption reflow resistance of the cured product may decrease.

[0034] [Acid anhydride hardener (B)] The acid anhydride curing agent (B) in the thermosetting epoxy resin composition of the present invention is a compound that has the function of curing a compound having an epoxy group. As the acid anhydride curing agent (B), a known or commonly used acid anhydride curing agent for epoxy resins can be used. As the acid anhydride curing agent (B), an acid anhydride that is liquid at 25°C is preferable, and examples thereof include methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, dodecenylsuccinic anhydride, and methylendomethylenetetrahydrophthalic anhydride. In addition, for example, an acid anhydride that is solid at room temperature (about 25°C), such as phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, and methylcyclohexene dicarboxylic anhydride, can be dissolved in an acid anhydride that is liquid at room temperature (about 25°C) to form a liquid mixture, and can be preferably used as the acid anhydride curing agent (B) in the present invention. The acid anhydride curing agent (B) can be used alone or in combination of two or more. As described above, the acid anhydride curing agent (B) is preferably an anhydride of a saturated monocyclic hydrocarbon dicarboxylic acid (including those having a substituent such as an alkyl group bonded to the ring) from the viewpoint of the heat resistance, light resistance, and crack resistance of the cured product.

[0035] In the present invention, as the acid anhydride curing agent (B), commercially available products such as "RIKACID MH-700" (manufactured by New Japan Chemical Co., Ltd.), "RIKACID MH-700F" (manufactured by New Japan Chemical Co., Ltd.), and "HN-5500" (manufactured by Hitachi Chemical Co., Ltd.) can also be used.

[0036] The content (mixture amount) of the acid anhydride curing agent (B) is not particularly limited, but is preferably 20 to 200 parts by weight, more preferably 30 to 145 parts by weight, based on the total amount (100 parts by weight) of the compound having an epoxy group contained in the thermosetting epoxy resin composition of the present invention. If the content of the acid anhydride curing agent (B) is less than 20 parts by weight, the curing is insufficient and the toughness of the cured product tends to decrease. On the other hand, if the content of the acid anhydride curing agent (B) is more than 200 parts by weight, the cured product may become colored and the hue may deteriorate.

[0037] The content (mixture amount) of the acid anhydride curing agent (B) is not particularly limited, but it is preferable to use an amount of preferably 0.01 to 1.0 equivalent, more preferably 0.1 to 1.0 equivalent, and even more preferably 0.2 to 1.0 equivalent, relative to 1 equivalent of epoxy groups in all compounds having epoxy groups contained in the thermosetting epoxy resin composition of the present invention. If the content of the acid anhydride curing agent (B) is less than 0.01 equivalent, curing becomes insufficient and the toughness of the cured product tends to decrease. On the other hand, if the content of the acid anhydride curing agent (B) exceeds 1.0 equivalent, the cured product may become colored and the hue may deteriorate.

[0038] [Thermal cationic curing catalyst (C)] The thermosetting epoxy resin composition of the present invention further contains a thermal cationic curing catalyst (C) as an essential component. The above-mentioned thermal cationic curing catalyst (C) is a compound that has the function of initiating and / or accelerating the curing reaction of a compound having an epoxy group by heating. By containing the thermal cationic curing catalyst (C) in addition to the acid anhydride curing agent (B) and the compound (D) described below in the thermosetting epoxy resin composition of the present invention, the gelation time of the resin composition is shortened, the curing process is shortened, and the production efficiency is improved. In addition, the time to gelation is shortened, and as a result, the volatilization of monomer components such as the acid anhydride curing agent can be suppressed. The thermal cationic curing catalyst (C) is not particularly limited, but examples thereof include cationic catalysts (thermal cationic polymerization initiators) that generate cationic species by heat treatment and initiate polymerization.

[0039] Examples of the thermal cationic curing catalyst that generates cationic species by applying a heat treatment include aryl diazonium salts, aryl iodonium salts, aryl sulfonium salts, and allene-ion complexes. Commercially available products such as "PP-33", "CP-66", and "CP-77" (manufactured by ADEKA Corporation); "FC-509" (manufactured by 3M); "UVE1014" (manufactured by GE); "San-Aid SI-60L", "San-Aid SI-80L", "San-Aid SI-100L", "San-Aid SI-110L", and "San-Aid SI-150L" (manufactured by Sanshin Chemical Industry Co., Ltd.); and "CG-24-61" (manufactured by Ciba Japan) can be preferably used. The thermal cationic curing catalyst (C) can be used alone or in combination of two or more kinds.

[0040] The content (mixture amount) of the thermal cationic curing catalyst (C) is not particularly limited, but is preferably 0.01 to 15 parts by weight, more preferably 0.01 to 12 parts by weight, even more preferably 0.05 to 10 parts by weight, and particularly preferably 0.1 to 10 parts by weight, based on the total amount (100 parts by weight) of the compound having an epoxy group contained in the thermosetting epoxy resin composition. By using the thermal cationic curing catalyst (C) within the above range, a cured product excellent in heat resistance, light resistance, and transparency can be obtained. In addition, the gelation time is shortened, the curing process is shortened, and the production efficiency is improved, and the volatilization of monomer components such as acid anhydride curing agents can be suppressed.

[0041] [One or more compounds (D) selected from the group consisting of organic acid metal salts and metal chelate compounds] The thermosetting epoxy resin composition of the present invention further contains, as an essential component, one or more compounds (D) selected from the group consisting of organic acid metal salts and metal chelate compounds (hereinafter, sometimes simply referred to as "compound (D)") as a curing accelerator. The compound (D) is a compound that has the function of accelerating the curing rate when a compound having an epoxy group is cured by an acid anhydride curing agent (B). By containing the compound (D) as a curing accelerator together with the acid anhydride curing agent (B) and the thermal cationic curing catalyst (C), the gelation time of the resin composition is shortened, the curing process is shortened, the production efficiency is improved, and the volatilization of monomer components such as the acid anhydride curing agent can be suppressed.

[0042] The "metal" constituting the compound (D) is not particularly limited, and examples thereof include magnesium (Mg), calcium (Ca), zinc (Zn), cobalt (Co), nickel (Ni), tin (Sn), barium (Ba), iron (Fe), aluminum (Al), copper (Cu), manganese (Mn), zirconium (Zr), titanium (Ti), indium (In), and lead (Pb). These metal atoms may be contained in the compound (D) alone or in combination of two or more. Among them, at least one selected from zinc, calcium, and zirconium is preferred from the viewpoint of shortening the gelation time of the resin composition. That is, the compound (D) is more preferably an organic acid zinc salt, a zinc chelate compound, an organic acid zirconium salt, a zirconium chelate compound, an organic acid calcium salt, or a calcium chelate compound.

[0043] The organic acid constituting the organic acid metal salt in the compound (D) is not particularly limited, but an organic carboxylic acid is preferred. The organic carboxylic acid may be any known or commonly used one, and is not particularly limited, but is preferably one or two of aliphatic carboxylic acids having 6 to 18 carbon atoms, linear, branched, or ether group-containing, and aromatic carboxylic acids having 6 to 18 carbon atoms, specifically, aliphatic carboxylic acids such as octyl acid, lauric acid, stearic acid, neodecanoic acid, and oleic acid, and aromatic carboxylic acids such as benzoic acid and naphthyl acid. In particular, octyl acid and naphthyl acid are preferred from the viewpoint of shortening the gelation time of the resin composition. The compound (D) may contain one of the organic acids alone, or two or more of them in combination.

[0044] The organic acid metal salt can be produced by a known or conventional method. In addition, as the organic acid metal salt, commercially available products such as "Nikka Octix Zinc" and "Naphtex Zinc" (both manufactured by Nippon Kagaku Sangyo Co., Ltd.), "Octope Zr", "Octope Ca", and "Octope Zn" (both manufactured by Hope Pharmaceutical Co., Ltd.) can also be used.

[0045] As the metal chelate compound in the compound (D), known or conventional compounds can be used. Among them, the metal chelate compound is preferably a metal chelate compound having a β-diketone as a chelate component. Examples of the β-diketone include acetylacetone, benzoylacetone, stearoylbenzoylmethane, dibenzoylmethane, ethyl acetoacetate, and dehydroacetic acid. In particular, a metal chelate compound having acetylacetone as a chelate component is preferred, and more preferably bis(acetylacetonato)aquazinc(II) (bis(2,4-pentanedionato)zinc(II)) [Zn(C 5 H 7 O 2 ) 2 (H 2 The above metal chelate compounds can be used alone or in combination of two or more.

[0046] The metal chelate compound can be produced by a known or conventional method, for example, by reacting a metal with a β-diketone and an alkali. In addition, as the metal chelate compound, a commercially available product such as Nursem Zinc (manufactured by Nippon Kagaku Sangyo Co., Ltd.) can also be used.

[0047] The thermosetting epoxy resin composition of the present invention may contain one type of compound (D) alone or in combination of two or more types. As the compound (D), zinc octylate, zinc naphthylate, zirconium octylate, zirconium naphthylate, calcium octylate, calcium naphthylate, bis(acetylacetonato)aquazinc(II), etc. are preferred.

[0048] The content (mixture amount) of the compound (D) is not particularly limited, but is preferably 0.01 to 5 parts by weight, more preferably 0.05 to 5 parts by weight, and even more preferably 0.1 to 5 parts by weight, based on the total amount (100 parts by weight) of the compounds having an epoxy group contained in the thermosetting epoxy resin composition. If the content of the compound (D) is less than 0.01 parts by weight, the gelation time of the resin composition may be extended, and monomer components such as an acid anhydride curing agent may be easily volatilized. On the other hand, if the content of the compound (D) exceeds 5 parts by weight, the moisture absorption reflow resistance of the cured product may be reduced. In addition, when the thermosetting epoxy resin composition of the present invention contains two or more compounds as the compound (D), it is preferable to control the total amount (total content) of these within the above range.

[0049] [Antioxidants (E)] The thermosetting epoxy resin composition of the present invention may contain an antioxidant (E). By containing the antioxidant (E), it becomes possible to produce a cured product having even more excellent heat resistance (particularly, yellowing resistance). As the antioxidant (E), a known or commonly used antioxidant can be used, and it is not particularly limited, but examples thereof include phenol-based antioxidants (phenol-based compounds), hindered amine-based antioxidants (hindered amine-based compounds), phosphorus-based antioxidants (phosphorus-based compounds), and sulfur-based antioxidants (sulfur-based compounds).

[0050] Examples of phenol-based antioxidants include monophenols such as 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-p-ethylphenol, and stearyl-β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate; 2,2'-methylenebis(4-methyl-6-t-butylphenol), 2,2'-methylenebis(4-ethyl-6-t-butylphenol), 4,4'-thiobis(3-methyl-6-t-butylphenol), 4,4'-butylidenebis(3-methyl-6-t-butylphenol), 3,9-bis[1,1-dimethyl-2-{β-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]2,4,8,1 Bisphenols such as 0-tetraoxaspiro[5.5]undecane; and polymeric phenols such as 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, tetrakis-[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, bis[3,3'-bis-(4'-hydroxy-3'-t-butylphenyl)butyric acid]glycol ester, 1,3,5-tris(3',5'-di-t-butyl-4'-hydroxybenzyl)-s-triazine-2,4,6-(1H,3H,5H)trione, and tocopherol.

[0051] Examples of the hindered amine antioxidant include bis(1,2,2,6,6-pentamethyl-4-piperidyl)[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butyl malonate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate, methyl-1,2,2,6,6-pentamethyl-4-piperidylsebacate, and 4-benzoyloxy-2,2,6,6-tetramethylpiperidine.

[0052] Examples of phosphorus-based antioxidants include triphenyl phosphite, diphenyl isodecyl phosphite, phenyl diisodecyl phosphite, tris(nonylphenyl) phosphite, diisodecyl pentaerythritol phosphite, tris(2,4-di-t-butylphenyl) phosphite, cyclic neopentane tetrayl bis(octadecyl) phosphite, cyclic neopentane tetrayl bis(2,4-di-t-butylphenyl) phosphite, cyclic neopentane tetrayl bis(2, phosphites such as bis[2-t-butyl-6-methyl-4-{2-(octadecyloxycarbonyl)ethyl}phenyl]hydrogen phosphite; and oxaphosphaphenanthrene oxides such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 10-(3,5-di-t-butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

[0053] Examples of sulfur-based antioxidants include dodecanethiol, dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, and distearyl-3,3'-thiodipropionate.

[0054] In the thermosetting epoxy resin composition of the present invention, the antioxidant (E) may be used alone or in combination of two or more. The antioxidant (E) may be produced by a known or conventional method, or may be a commercially available product such as "Irganox1010" (BASF, phenolic antioxidant), "AO-60" or "AO-80" (ADEKA Corporation, phenolic antioxidant), "Irgafos168" (BASF, phosphorus-based antioxidant), "Adeka STAB HP-10" or "Adeka STAB PEP-36" (ADEKA Corporation, phosphorus-based antioxidant), or "HCA" (SANKO Co., Ltd., phosphorus-based antioxidant).

[0055] When the thermosetting epoxy resin composition of the present invention contains an antioxidant (E), the content (mixture amount) of the antioxidant (E) is not particularly limited, but is preferably 0.1 to 5 parts by weight, more preferably 0.5 to 3 parts by weight, based on the total amount (100 parts by weight) of the compound having an epoxy group contained in the thermosetting epoxy resin composition. By making the content of the antioxidant (E) 0.1 parts by weight or more, oxidation of the cured product is efficiently prevented, and the heat resistance and yellowing resistance tend to be further improved. On the other hand, by making the content of the antioxidant (E) 5 parts by weight or less, coloration is suppressed, and a cured product with a better hue tends to be obtained.

[0056] [Monoallyl diglycidyl isocyanurate compound (F)] The thermosetting epoxy resin composition of the present invention may contain a monoallyl diglycidyl isocyanurate compound (F) represented by the following formula (1). The monoallyl diglycidyl isocyanurate compound (F) plays a role in particular of improving the toughness of the cured product, and improving the thermal shock resistance and moisture absorption reflow resistance (particularly, crack resistance (characteristics that make it difficult for cracks to occur) during heat treatment in the reflow step after moisture absorption). [ka]

[0057] In the above formula (1), R 1 , R 2 Each of (the same or different) represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. Examples of the alkyl group having 1 to 8 carbon atoms include a straight-chain or branched-chain alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a s-butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group. Among these, a straight-chain or branched-chain alkyl group having 1 to 3 carbon atoms such as a methyl group, an ethyl group, a propyl group, and an isopropyl group is preferred. R in the above formula (1) 1 and R 2 is particularly preferably a hydrogen atom.

[0058] Representative examples of the monoallyl diglycidyl isocyanurate compound (F) include monoallyl diglycidyl isocyanurate, 1-allyl-3,5-bis(2-methylepoxypropyl)isocyanurate, 1-(2-methylpropenyl)-3,5-diglycidyl isocyanurate, 1-(2-methylpropenyl)-3,5-bis(2-methylepoxypropyl)isocyanurate, etc. The monoallyl diglycidyl isocyanurate compound (F) can be used alone or in combination of two or more.

[0059] The monoallyl diglycidyl isocyanurate compound (F) may be used after being previously modified by adding a compound that reacts with an epoxy group, such as an alcohol or an acid anhydride.

[0060] When the thermosetting epoxy resin composition of the present invention contains the monoallyl diglycidyl isocyanurate compound (F), its content (blended amount) is not particularly limited, but is preferably 5 to 60% by weight, more preferably 8 to 55% by weight, and even more preferably 10 to 50% by weight, based on the total amount (100% by weight) of the compounds having an epoxy group contained in the thermosetting epoxy resin composition. If the content of the monoallyl diglycidyl isocyanurate compound (F) exceeds 60% by weight, the solubility of the monoallyl diglycidyl isocyanurate compound (F) in the thermosetting epoxy resin composition decreases, which may adversely affect the physical properties of the cured product. On the other hand, if the content of the monoallyl diglycidyl isocyanurate compound (F) is less than 5% by weight, the thermal shock resistance and moisture absorption reflow resistance of the cured product may decrease.

[0061] In addition, when the thermosetting epoxy resin composition of the present invention contains a monoallyl diglycidyl isocyanurate compound (F), the content (mixture amount) of the monoallyl diglycidyl isocyanurate compound (F) relative to the total amount (100% by weight) of the alicyclic epoxy compound (A) and the monoallyl diglycidyl isocyanurate compound (F) is not particularly limited, but is preferably 5 to 60% by weight, more preferably 8 to 55% by weight, and even more preferably 10 to 50% by weight. If the content of the monoallyl diglycidyl isocyanurate compound (F) exceeds 60% by weight, the solubility of the monoallyl diglycidyl isocyanurate compound (F) in the thermosetting epoxy resin composition decreases, which may adversely affect the physical properties of the cured product. On the other hand, if the content of the monoallyl diglycidyl isocyanurate compound (F) is less than 5% by weight, the thermal shock resistance and moisture absorption reflow resistance of the cured product may decrease.

[0062] [Alicyclic polyester resin] The thermosetting epoxy resin composition of the present invention preferably further contains an alicyclic polyester resin. By containing the alicyclic polyester resin, in particular, the heat resistance and light resistance of the cured product are improved, and the decrease in luminous intensity of the optical semiconductor device tends to be further suppressed. The alicyclic polyester resin is a polyester resin having at least an alicyclic structure (aliphatic ring structure). In particular, from the viewpoint of improving the heat resistance and light resistance of the cured product, the alicyclic polyester resin is preferably an alicyclic polyester resin having an alicyclic ring (alicyclic structure) in the main chain.

[0063] The alicyclic structure in the alicyclic polyester resin is not particularly limited, and examples thereof include monocyclic hydrocarbon structures and bridged ring hydrocarbon structures (e.g., bicyclic hydrocarbons, etc.). Among them, a saturated monocyclic hydrocarbon structure or a saturated bridged ring hydrocarbon structure in which the alicyclic skeleton (carbon-carbon bond) is entirely composed of carbon-carbon single bonds is particularly preferred. The alicyclic structure in the alicyclic polyester resin may be introduced into either one of the dicarboxylic acid-derived structural unit and the diol-derived structural unit, or may be introduced into both, and is not particularly limited.

[0064] The alicyclic polyester resin has a structural unit derived from a monomer component having an alicyclic structure. Examples of the monomer having an alicyclic structure include known or conventional diols and dicarboxylic acids having an alicyclic structure, and are not particularly limited. For example, dicarboxylic acids having an alicyclic structure (including derivatives such as acid anhydrides) such as 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid, hymic acid, 1,4-decahydronaphthalenedicarboxylic acid, 1,5-decahydronaphthalenedicarboxylic acid, 2,6-decahydronaphthalenedicarboxylic acid, and 2,7-decahydronaphthalenedicarboxylic acid; 1,2-cyclopentanedicarboxylic acid; 5-membered ring diols such as 1,3-cyclopentanediol, 1,2-cyclopentanedimethanol, 1,3-cyclopentanedimethanol, and bis(hydroxymethyl)tricyclo[5.2.1.0]decane; 6-membered ring diols such as 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, and 2,2-bis-(4-hydroxycyclohexyl)propane; and diols having an alicyclic structure such as hydrogenated bisphenol A (including derivatives thereof).

[0065] The alicyclic polyester resin may have a constituent unit derived from a monomer component that does not have an alicyclic structure. Examples of the monomer that does not have an alicyclic structure include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, and naphthalenedicarboxylic acid (including derivatives such as acid anhydrides); aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, succinic acid, fumaric acid, and maleic acid (including derivatives such as acid anhydrides); ethylene glycol, propylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, and the like. Examples of the diol include diols (including derivatives thereof) such as diol, 1,5-pentanediol, 1,6-hexanediol, 3-methylpentanediol, diethylene glycol, 3-methyl-1,5-pentanediol, 2-methyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, xylylene glycol, an ethylene oxide adduct of bisphenol A, and a propylene oxide adduct of bisphenol A. Note that the above dicarboxylic acids and diols not having an alicyclic structure to which an appropriate substituent (e.g., an alkyl group, an alkoxy group, a halogen atom, etc.) is bonded are also included in the monomers not having an alicyclic structure.

[0066] The ratio of the monomer units having an alicyclic ring to all monomer units (all monomer components) constituting the alicyclic polyester resin (100 mol%) is not particularly limited, but is preferably 10 mol% or more (for example, 10 to 80 mol%), more preferably 25 to 70 mol%, and even more preferably 40 to 60 mol%. If the ratio of the monomer units having an alicyclic ring is less than 10 mol%, the heat resistance, light resistance, thermal shock resistance, and moisture absorption reflow resistance of the cured product may decrease.

[0067] As the alicyclic polyester resin, particularly preferred is an alicyclic polyester resin containing at least one of the structural units represented by the following formulas (2) to (4).

[0068] [ka] [In the formula, R 3 represents a linear, branched, or cyclic alkylene group having 2 to 15 carbon atoms. 4 ~R 7 each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms; R 4 ~R 7 Two selected from may be bonded to form a ring.

[0069] [ka] [In the formula, R 3 represents a linear, branched, or cyclic alkylene group having 2 to 15 carbon atoms. 4 ~R 7 each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms; R 4 ~R 7 Two selected from may be bonded to form a ring.

[0070] [ka] [In the formula, R 3 represents a linear, branched, or cyclic alkylene group having 2 to 15 carbon atoms. 4 ~R 7 each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms; R 4 ~R 7 Two selected from may be bonded to form a ring.

[0071] A preferred specific example of the structural units represented by the above formulas (2) to (4) is a structural unit derived from 4-methyl-1,2-cyclohexanedicarboxylic acid and ethylene glycol, represented by the following formula (5): An alicyclic polyester resin having this structural unit can be obtained, for example, by polycondensing methylhexahydrophthalic anhydride and ethylene glycol. [ka]

[0072] Further, other preferred specific examples of the structural units represented by the above formulas (2) to (4) include a structural unit derived from 1,4-cyclohexanedicarboxylic acid and neopentyl glycol, represented by the following formula (6): An alicyclic polyester resin having this structural unit can be obtained, for example, by polycondensing 1,4-cyclohexanedicarboxylic acid and neopentyl glycol. [ka]

[0073] When the alicyclic polyester resin has the structural units represented by the formulas (2) to (4), the total content of the structural units (total content; all monomer units constituting the structural units) is not particularly limited, but is preferably 20 mol% or more (for example, 20 to 100 mol%), more preferably 50 to 100 mol%, and even more preferably 80 to 100 mol% relative to the total structural units of the alicyclic polyester resin (100 mol%; all monomer units constituting the alicyclic polyester resin). If the content of the structural units represented by the formulas (2) to (4) is less than 20 mol%, the heat resistance, light resistance, thermal shock resistance, and moisture absorption reflow resistance of the cured product may be reduced.

[0074] The number average molecular weight of the alicyclic polyester resin is not particularly limited, but is preferably 300 to 100,000, and more preferably 300 to 30,000. If the number average molecular weight of the alicyclic polyester resin is less than 300, the toughness of the cured product may be insufficient, and the thermal shock resistance and moisture absorption reflow resistance may be reduced. On the other hand, if the number average molecular weight of the alicyclic polyester resin exceeds 100,000, the compatibility with the curing agent (D) may be reduced, and the transparency of the cured product may be reduced. The number average molecular weight of the alicyclic polyester resin can be measured, for example, by GPC (gel permeation chromatography) method as a value converted into standard polystyrene.

[0075] The alicyclic polyester resins may be used alone or in combination of two or more.

[0076] The alicyclic polyester resin is not particularly limited and can be produced by a known or conventional method. More specifically, for example, the alicyclic polyester resin can be obtained by polycondensing the above-mentioned dicarboxylic acid and diol by a conventional method, or by polycondensing the above-mentioned dicarboxylic acid derivative (anhydride, ester, acid halide, etc.) and diol by a conventional method.

[0077] In the thermosetting epoxy resin composition of the present invention, the content (mixture amount) of the alicyclic polyester resin is not particularly limited, but when the curable resin composition contains a curing agent (D), the content is preferably 1 to 60% by weight, more preferably 5 to 30% by weight, based on the total amount (100% by weight) of the alicyclic polyester resin and the curing agent (D). If the content of the alicyclic polyester resin is less than 1% by weight, the thermal shock resistance and moisture absorption reflow resistance of the cured product may be insufficient. On the other hand, if the content of the alicyclic polyester resin is more than 60% by weight, the transparency and heat resistance of the cured product may be reduced.

[0078] The content (mixture amount) of the alicyclic polyester resin relative to the total amount (100 parts by weight) of the compounds having an epoxy group contained in the thermosetting epoxy resin composition is not particularly limited, but is preferably 5 to 50 parts by weight, more preferably 10 to 45 parts by weight, and even more preferably 15 to 40 parts by weight. If the content of the alicyclic polyester resin is less than 5 parts by weight, the heat resistance, light resistance, thermal shock resistance, and moisture absorption reflow resistance of the cured product may be insufficient. On the other hand, if the content of the alicyclic polyester resin exceeds 50 parts by weight, the heat shock resistance and moisture absorption reflow resistance of the cured product may be reduced.

[0079] [Siloxane derivatives with two or more epoxy groups in the molecule] The thermosetting epoxy resin composition of the present invention preferably further contains a siloxane derivative having two or more epoxy groups in the molecule (in one molecule). By containing the siloxane derivative having two or more epoxy groups in the molecule, the heat resistance and light resistance of the cured product can be particularly improved to a higher level.

[0080] The siloxane skeleton (Si-O-Si skeleton) in the siloxane derivative having two or more epoxy groups in the molecule is not particularly limited, and examples thereof include cyclic siloxane skeletons; linear silicones, and polysiloxane skeletons such as cage-type and ladder-type polysilsesquioxanes. Among them, the siloxane skeleton is preferably a cyclic siloxane skeleton or a linear silicone skeleton from the viewpoint of improving the heat resistance and light resistance of the cured product and suppressing the decrease in luminous intensity. That is, the siloxane derivative having two or more epoxy groups in the molecule is preferably a cyclic siloxane having two or more epoxy groups in the molecule, or a linear silicone having two or more epoxy groups in the molecule. The siloxane derivative having two or more epoxy groups in the molecule can be used alone or in combination of two or more.

[0081] When the siloxane derivative having two or more epoxy groups in the molecule is a cyclic siloxane having two or more epoxy groups, the number of Si-O units forming the siloxane ring (equal to the number of silicon atoms forming the siloxane ring) is not particularly limited, but is preferably 2 to 12, and more preferably 4 to 8, from the viewpoint of improving the heat resistance and light resistance of the cured product.

[0082] The weight average molecular weight of the siloxane derivative having two or more epoxy groups in the molecule is not particularly limited, but is preferably 100 to 3,000, and more preferably 180 to 2,000, from the viewpoint of improving the heat resistance and light resistance of the cured product.

[0083] The number of epoxy groups in one molecule of the siloxane derivative having two or more epoxy groups in the molecule is not particularly limited as long as it is two or more, but from the viewpoint of improving the heat resistance and light resistance of the cured product, it is preferably 2 to 4 (2, 3, or 4).

[0084] The epoxy equivalent (based on JIS K7236) of the siloxane derivative having two or more epoxy groups in the molecule is not particularly limited, but from the viewpoint of improving the heat resistance and light resistance of the cured product, it is preferably 180 to 400, more preferably 240 to 400, and even more preferably 240 to 350.

[0085] The epoxy group in the siloxane derivative having two or more epoxy groups in the molecule is not particularly limited, but from the viewpoint of improving the heat resistance and light resistance of the cured product, it is preferably an epoxy group composed of two adjacent carbon atoms and an oxygen atom that constitute an aliphatic ring (alicyclic epoxy group), and among these, a cyclohexene oxide group is particularly preferred.

[0086] Specific examples of the siloxane derivative having two or more epoxy groups in the molecule include 2,4-di[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-2,4,6,6,8,8-hexamethyl-cyclotetrasiloxane, 4,8-di[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-2,2,4,6,6,8-hexamethyl-cyclotetrasiloxane, 2,4-di[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-6,8-dipropyl-2,4,6,8-tetramethyl-cyclotetrasiloxane, 4,8-di[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]- 2,6-dipropyl-2,4,6,8-tetramethyl-cyclotetrasiloxane, 2,4,8-tri[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-2,4,6,6,8-pentamethyl-cyclotetrasiloxane, 2,4,8-tri[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-6-propyl-2,4,6,8-tetramethyl-cyclotetrasiloxane, 2,4,6,8-tetra[2-(3-{oxabicyclo[4.1.0]heptyl})ethyl]-2,4,6,8-tetramethyl-cyclotetrasiloxane, silsesquioxane having two or more epoxy groups in the molecule, etc. More specifically, for example, cyclic siloxane having two or more epoxy groups in the molecule represented by the following formula, etc. can be mentioned. [ka]

[0087] In addition, examples of the siloxane derivative having two or more epoxy groups in the molecule include an alicyclic epoxy group-containing silicone resin described in JP-A-2008-248169 and an organopolysilsesquioxane resin having at least two epoxy functional groups in one molecule described in JP-A-2008-19422.

[0088] As the siloxane derivative having two or more epoxy groups in the molecule, for example, commercially available products such as "X-40-2678" (manufactured by Shin-Etsu Chemical Co., Ltd.), "X-40-2670" (manufactured by Shin-Etsu Chemical Co., Ltd.), and "X-40-2720" (manufactured by Shin-Etsu Chemical Co., Ltd.), which are cyclic siloxanes having two or more epoxy groups in the molecule, can be used.

[0089] The content (mixture amount) of the siloxane derivative having two or more epoxy groups in the molecule is not particularly limited, but is preferably 5 to 60% by weight, more preferably 8 to 55% by weight, even more preferably 10 to 50% by weight, and particularly preferably 15 to 40% by weight, based on the total amount (100% by weight) of the compound having an epoxy group contained in the thermosetting epoxy resin composition. If the content of the siloxane derivative having two or more epoxy groups in the molecule is less than 5% by weight, the heat resistance and light resistance of the cured product may be insufficient. On the other hand, if the content of the siloxane derivative having two or more epoxy groups in the molecule exceeds 60% by weight, the thermal shock resistance and moisture absorption reflow resistance of the cured product may be reduced.

[0090] In addition, the content (mixture amount) of the siloxane derivative having two or more epoxy groups in the molecule relative to 100 parts by weight of the alicyclic epoxy compound (A) is not particularly limited, but is preferably 10 to 200 parts by weight, more preferably 20 to 180 parts by weight, even more preferably 30 to 150 parts by weight, and particularly preferably 35 to 145 parts by weight. If the content of the siloxane derivative having two or more epoxy groups in the molecule is less than 10 parts by weight, the heat resistance, light resistance, heat shock resistance, and moisture absorption reflow resistance of the cured product may be insufficient. On the other hand, if the content of the siloxane derivative having two or more epoxy groups in the molecule exceeds 200 parts by weight, the heat shock resistance and moisture absorption reflow resistance of the cured product may be reduced.

[0091] [Rubber particles] The thermosetting epoxy resin composition of the present invention may further contain rubber particles. Examples of the rubber particles include particulate NBR (acrylonitrile-butadiene rubber), reactive terminal carboxyl group NBR (CTBN), metal-free NBR, and particulate SBR (styrene-butadiene rubber). The rubber particles are preferably rubber particles having a multilayer structure (core-shell structure) consisting of a core part having rubber elasticity and at least one shell layer covering the core part. The rubber particles are particularly preferably rubber particles composed of a polymer (polymer) containing a (meth)acrylic acid ester as an essential monomer component, and having hydroxyl groups and / or carboxyl groups (either one or both of hydroxyl groups and carboxyl groups) on the surface as functional groups that can react with a compound having an epoxy group such as an alicyclic epoxy compound (A). If the hydroxyl groups and / or carboxyl groups are not present on the surface of the rubber particles, the cured product becomes cloudy due to thermal shock such as a cooling and heating cycle, and transparency decreases, which is not preferable.

[0092] The polymer constituting the core part having rubber elasticity in the rubber particles is not particularly limited, but it is preferable that the essential monomer component is a (meth)acrylic acid ester such as methyl (meth)acrylate, ethyl (meth)acrylate, or butyl (meth)acrylate. The polymer constituting the core part having rubber elasticity may also contain, as a monomer component, an aromatic vinyl such as styrene or α-methylstyrene, a nitrile such as acrylonitrile or methacrylonitrile, a conjugated diene such as butadiene or isoprene, ethylene, propylene, or isobutene.

[0093] Among them, the polymer constituting the core part having rubber elasticity preferably contains, as a monomer component, one or more selected from the group consisting of aromatic vinyl, nitrile, and conjugated diene together with (meth)acrylic acid ester. That is, examples of the polymer constituting the core part include binary copolymers such as (meth)acrylic acid ester / aromatic vinyl, (meth)acrylic acid ester / conjugated diene, and ternary copolymers such as (meth)acrylic acid ester / aromatic vinyl / conjugated diene. The polymer constituting the core part may contain silicones such as polydimethylsiloxane and polyphenylmethylsiloxane, polyurethane, and the like.

[0094] The polymer constituting the core portion may contain, as other monomer components, reactive crosslinking monomers having two or more reactive functional groups in one monomer (one molecule), such as divinylbenzene, allyl (meth)acrylate, ethylene glycol di(meth)acrylate, diallyl maleate, triallyl cyanurate, diallyl phthalate, and butylene glycol diacrylate.

[0095] It is preferable that the core portion of the above-mentioned rubber particles is composed of a binary copolymer of (meth)acrylic acid ester / aromatic vinyl (particularly, butyl acrylate / styrene), since this makes it possible to easily adjust the refractive index of the rubber particles.

[0096] The core portion of the rubber particles can be produced by a commonly used method, for example, by polymerizing the monomers by emulsion polymerization. In the emulsion polymerization method, the entire amount of the monomers may be charged at once and polymerized, or a part of the monomers may be polymerized and then the remainder may be added continuously or intermittently and polymerized, or a polymerization method using seed particles may be used.

[0097] The polymer constituting the shell layer of the rubber particles is preferably a different type of polymer from the polymer constituting the core portion. As described above, the shell layer preferably has a hydroxyl group and / or a carboxyl group as a functional group capable of reacting with a compound having an epoxy group such as the alicyclic epoxy compound (A). This can improve adhesion, particularly at the interface with the alicyclic epoxy compound (A), and can provide excellent crack resistance to a cured product obtained by curing a thermosetting epoxy resin composition containing the rubber particles having the shell layer. In addition, a decrease in the glass transition temperature of the cured product can be prevented.

[0098] The polymer constituting the shell layer preferably contains a (meth)acrylic acid ester such as methyl (meth)acrylate, ethyl (meth)acrylate, or butyl (meth)acrylate as an essential monomer component. For example, when butyl acrylate is used as the (meth)acrylic acid ester in the core portion, it is preferable to use a (meth)acrylic acid ester other than butyl acrylate (e.g., methyl (meth)acrylate, ethyl (meth)acrylate, butyl methacrylate, etc.) as a monomer component of the polymer constituting the shell layer. Examples of monomer components that may be contained other than the (meth)acrylic acid ester include aromatic vinyls such as styrene and α-methylstyrene, and nitriles such as acrylonitrile and methacrylonitrile. In the rubber particles, it is preferable to contain the above monomers alone or in combination with two or more kinds of (meth)acrylic acid esters as monomer components constituting the shell layer, and in particular, it is preferable to contain at least aromatic vinyl in terms of being able to easily adjust the refractive index of the rubber particles.

[0099] Furthermore, the polymer constituting the shell layer preferably contains, as a monomer component, a hydroxyl group-containing monomer (e.g., a hydroxyalkyl (meth)acrylate such as 2-hydroxyethyl (meth)acrylate) or a carboxyl group-containing monomer (e.g., an α,β-unsaturated acid such as (meth)acrylic acid, an α,β-unsaturated acid anhydride such as maleic anhydride, etc.) in order to form a hydroxyl group and / or a carboxyl group as a functional group capable of reacting with a compound having an epoxy group such as the alicyclic epoxy compound (A).

[0100] The polymer constituting the shell layer of the rubber particles preferably contains, as a monomer component, one or more selected from the above monomers in combination with a (meth)acrylic acid ester. That is, the shell layer is preferably a shell layer composed of, for example, a terpolymer such as a (meth)acrylic acid ester / aromatic vinyl / hydroxyalkyl (meth)acrylate or a (meth)acrylic acid ester / aromatic vinyl / α,β-unsaturated acid terpolymer.

[0101] In addition, the polymer constituting the shell layer may contain, as other monomer components, reactive crosslinking monomers having two or more reactive functional groups in one monomer (one molecule), such as divinylbenzene, allyl (meth)acrylate, ethylene glycol di(meth)acrylate, diallyl maleate, triallyl cyanurate, diallyl phthalate, and butylene glycol diacrylate, in addition to the above-mentioned monomers, just like the core portion.

[0102] The rubber particles (rubber particles having a core-shell structure) are obtained by coating the core portion with a shell layer. Examples of a method for coating the core portion with a shell layer include a method of coating the surface of the core portion having rubber elasticity obtained by the above method with a copolymer constituting the shell layer, and a method of graft polymerization of the core portion having rubber elasticity obtained by the above method as a trunk component and each component constituting the shell layer as a branch component.

[0103] The average particle size of the rubber particles is not particularly limited, but is preferably 10 to 500 nm, more preferably 20 to 400 nm. The maximum particle size of the rubber particles is not particularly limited, but is preferably 50 to 1000 nm, more preferably 100 to 800 nm. If the average particle size exceeds 500 nm or the maximum particle size exceeds 1000 nm, the dispersibility of the rubber particles in the cured product may decrease, resulting in decreased crack resistance. On the other hand, if the average particle size is less than 10 nm or the maximum particle size is less than 50 nm, the effect of improving the crack resistance of the cured product may be difficult to obtain.

[0104] The refractive index of the rubber particles is not particularly limited, but is preferably 1.40 to 1.60, more preferably 1.42 to 1.58. The difference between the refractive index of the rubber particles and the refractive index of the cured product obtained by curing the thermosetting epoxy resin composition containing the rubber particles (the thermosetting epoxy resin composition of the present invention) is preferably within ±0.03. If the difference in refractive index exceeds ±0.03, the transparency of the cured product decreases, and sometimes becomes cloudy, and the luminosity of the optical semiconductor device tends to decrease, and the function of the optical semiconductor device may be lost.

[0105] The refractive index of rubber particles can be determined, for example, by pouring 1 g of rubber particles into a mold and compression-molding at 210°C and 4 MPa to obtain a 1 mm thick plate, cutting out a test piece 20 mm long x 6 mm wide from the obtained plate, and measuring the refractive index at 20°C and sodium D line using a multi-wavelength Abbe refractometer (product name "DR-M2", manufactured by Atago Co., Ltd.) while the test piece is in close contact with a prism using monobromonaphthalene as an intermediate liquid.

[0106] The refractive index of the cured product of the thermosetting epoxy resin composition of the present invention can be determined, for example, by cutting a test piece of 20 mm length × 6 mm width × 1 mm thickness from the cured product obtained by the heat curing method described in the section on optical semiconductor device below, and measuring the refractive index at 20°C at sodium D line using a multi-wavelength Abbe refractometer (product name "DR-M2", manufactured by Atago Co., Ltd.) in a state where the test piece is closely attached to a prism using monobromonaphthalene as an intermediate liquid.

[0107] The content (mixture amount) of the rubber particles in the thermosetting epoxy resin composition of the present invention is not particularly limited, but is preferably 0.5 to 30 parts by weight, more preferably 1 to 20 parts by weight, based on the total amount (100 parts by weight) of the compounds having an epoxy group contained in the thermosetting epoxy resin composition. If the content of the rubber particles is less than 0.5 parts by weight, the crack resistance of the cured product tends to decrease. On the other hand, if the content of the rubber particles is more than 30 parts by weight, the heat resistance of the cured product tends to decrease.

[0108] [Additives] In addition to the above, the thermosetting epoxy resin composition of the present invention may contain various additives within a range that does not impair the effects of the present invention. If a compound having a hydroxyl group such as ethylene glycol, diethylene glycol, propylene glycol, or glycerin is contained as the additive, the reaction can proceed slowly. In addition, conventional additives such as a photocation curing catalyst, a silicone-based or fluorine-based defoaming agent, a leveling agent, a silane coupling agent such as γ-glycidoxypropyltrimethoxysilane or 3-mercaptopropyltrimethoxysilane, a surfactant, an inorganic filler such as silica or alumina, a flame retardant, a colorant, an ultraviolet absorber, an ion adsorbent, a pigment, a fluorescent material, and a mold release agent can be used within a range that does not impair viscosity or transparency.

[0109] <Method for producing thermosetting epoxy resin composition> The thermosetting epoxy resin composition of the present invention may contain at least the above-mentioned alicyclic epoxy compound (A), acid anhydride curing agent (B), thermal cationic curing catalyst (C) and compound (D), and its manufacturing method (preparation method) is not particularly limited. Specifically, for example, it can be prepared by stirring and mixing each component in a predetermined ratio and degassing under vacuum as necessary, or it can be prepared by separately preparing a composition containing a compound having an epoxy group such as alicyclic epoxy compound (A) as an essential component (sometimes referred to as "epoxy resin") and a composition containing an acid anhydride curing agent (B), a thermal cationic curing catalyst (C) and compound (D) as essential components (sometimes referred to as "epoxy curing agent"), stirring and mixing the epoxy resin and the epoxy curing agent in a predetermined ratio and degassing under vacuum as necessary.

[0110] The temperature during stirring and mixing when preparing the epoxy resin is not particularly limited, but is preferably 30 to 150° C., and more preferably 35 to 130° C. The temperature during stirring and mixing when preparing the epoxy curing agent is not particularly limited, but is preferably 30 to 100° C., and more preferably 35 to 80° C. For stirring and mixing, known devices such as a rotation-revolution type mixer, a planetary mixer, a kneader, and a dissolver can be used.

[0111] In particular, when the thermosetting epoxy resin composition of the present invention contains the alicyclic polyester resin as an essential component, in order to obtain a more uniform composition, it is preferable to premix the alicyclic polyester resin with the acid anhydride curing agent (B) to obtain a mixture (a mixture of the alicyclic polyester resin and the acid anhydride curing agent (B)), and then blend the mixture with the thermal cationic curing catalyst (C), the compound (D), and other additives to prepare an epoxy curing agent, and then mix the epoxy curing agent with a separately prepared epoxy resin. The temperature at which the alicyclic polyester resin and the acid anhydride curing agent (B) are mixed is not particularly limited, but is preferably 60 to 130°C, more preferably 90 to 120°C. The mixing time is not particularly limited, but is preferably 30 to 100 minutes, more preferably 45 to 80 minutes. The mixing is not particularly limited, but is preferably performed under a nitrogen atmosphere. The above-mentioned known device can be used for mixing.

[0112] After mixing the alicyclic polyester resin with the acid anhydride curing agent (B), although not particularly limited, further suitable chemical treatment (e.g., hydrogenation or terminal modification of the alicyclic polyester resin, etc.) may be performed. In the mixture of the alicyclic polyester resin with the acid anhydride curing agent (B), a part of the acid anhydride curing agent (B) may react with the alicyclic polyester resin (e.g., hydroxyl groups of the alicyclic polyester resin, etc.).

[0113] As the mixture of the above-mentioned alicyclic polyester resin and acid anhydride curing agent (B), for example, commercially available products such as product names "HN-7200" (manufactured by Hitachi Chemical Co., Ltd.) and "HN-5700" (manufactured by Hitachi Chemical Co., Ltd.) can be used.

[0114] Since the thermosetting epoxy resin composition of the present invention contains an alicyclic epoxy compound (A), an acid anhydride curing agent (B), a thermal cationic curing catalyst (C), and a compound (D) as essential components, the curing reaction initiation temperature is low, the gelation time is shortened, and the curing process is shortened, thereby improving the production efficiency.

[0115] The curing reaction initiation temperature of the thermosetting epoxy resin composition of the present invention is preferably 150° C. or lower, more preferably 130° C. or lower, and further preferably 120° C. or lower. The curing reaction initiation temperature is the temperature at which an exothermic peak of the curing reaction first appears in measurement using a differential scanning calorimeter.

[0116] The gel time (seconds) of the thermosetting epoxy resin composition of the present invention is preferably 1050 seconds or less, more preferably 950 seconds or less, and further preferably 850 seconds or less. The gel time is the time (seconds) measured for the thermosetting epoxy resin composition in the test examples described later.

[0117] <Cured product> By curing the thermosetting epoxy resin composition of the present invention, a cured product having excellent heat resistance, light resistance, and thermal shock resistance, and particularly excellent moisture absorption reflow resistance, can be obtained. The heating temperature (curing temperature) during curing is not particularly limited, but is preferably 45 to 200°C, more preferably 100 to 190°C, and even more preferably 100 to 180°C. The heating time (curing time) during curing is not particularly limited, but is preferably 30 to 600 minutes, more preferably 45 to 540 minutes, and even more preferably 60 to 480 minutes. Since the thermosetting epoxy resin composition of the present invention has the above-mentioned constitution, the curing reaction can be efficiently progressed at a low curing temperature and a short curing time, but if the curing temperature and curing time are lower than the lower limit of the above range, the curing becomes insufficient, and conversely, if they are higher than the upper limit of the above range, decomposition of the resin component and volatilization of the monomer component such as the acid anhydride curing agent (B) may occur, so neither is preferable. The curing conditions depend on various conditions, but can be appropriately adjusted, for example, by shortening the curing time when the curing temperature is increased, and by lengthening the curing time when the curing temperature is decreased.

[0118] <Optical semiconductor encapsulation resin composition> The thermosetting epoxy resin composition of the present invention can be preferably used as a resin composition for sealing optical semiconductors. By using the resin composition for sealing optical semiconductors, an optical semiconductor device can be obtained in which an optical semiconductor element is sealed with a cured product having high heat resistance, light resistance, and thermal shock resistance, and particularly excellent moisture absorption reflow resistance. Even when the optical semiconductor device includes a high-output, high-brightness optical semiconductor element, the luminous intensity is unlikely to decrease over time, and in particular, degradation such as a decrease in luminous intensity is unlikely to occur even when the optical semiconductor device is stored under high humidity conditions and then heated in a reflow process.

[0119] <Optical semiconductor device> The optical semiconductor device of the present invention is an optical semiconductor device in which an optical semiconductor element is encapsulated with a cured product of the thermosetting epoxy resin composition (optical semiconductor encapsulation resin composition) of the present invention. The optical semiconductor element is encapsulated by injecting the thermosetting epoxy resin composition prepared by the above-mentioned method into a predetermined mold and curing it by heating under predetermined conditions. This results in an optical semiconductor device in which an optical semiconductor element is encapsulated with a cured product of the thermosetting epoxy resin composition. The curing temperature and curing time can be set in the same range as when preparing the cured product, and an optical semiconductor device can be efficiently manufactured in a short curing time. In addition, a reduction in the amount of resin due to volatilization of monomer components such as the acid anhydride curing agent (B) is also suppressed, so that a high-quality optical semiconductor device can be manufactured.

[0120] The thermosetting epoxy resin composition of the present invention has a short curing time and can efficiently form a cured product, and therefore the use is not limited to the above-mentioned sealing application of optical semiconductor elements, and can also be suitably used in applications such as adhesives, electrical insulating materials, laminates, coatings, inks, paints, sealants, resists, composite materials, transparent substrates, transparent sheets, transparent films, optical elements, optical lenses, optical members, photolithography, electronic paper, touch panels, solar cell substrates, optical waveguides, light guide plates, and holographic memories. EXAMPLES

[0121] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The blending amount of "organic acid metal salt" in the following Table 1 is the amount including the solvent component. Examples 1 to 6 are provided as reference examples.

[0122] Examples 1 to 9, Comparative Examples 1 to 7 According to the formulation (unit: parts by weight) shown in Tables 1 and 2, an alicyclic epoxy compound, other epoxy compounds, and an antioxidant were mixed and stirred at 80° C. for 1 hour. Next, this epoxy mixture was mixed uniformly with an acid anhydride curing agent (including an alicyclic ester resin), an organic acid metal salt, and a thermal cationic curing catalyst in the formulation ratios shown in Tables 1 and 2 using a planetary stirrer, and the mixture was degassed to obtain a thermosetting epoxy resin composition.

[0123] The above thermosetting epoxy resin composition was mixed in a Pyrex (registered trademark) glass test tube (rimless, outer diameter 12 mm × 90 mm, manufactured by AGC Technoglass Co., Ltd.) and weighed out in an amount of 1.5 g. A glass rod was inserted and the gel time at 120°C was measured using a product name "No. 153 Gel Time Tester" (manufactured by Yasuda Seiki Seisakusho Co., Ltd.). The results are shown in "Gel Time [s]" in Table 1.

[0124] The thermosetting epoxy resin compositions obtained in the examples and comparative examples were filled into a mold and heated in an oven (resin curing oven) at 120°C for 5 hours to obtain a cured product with a thickness of 3 mm. The light transmittance (thickness direction) of the obtained cured product at a wavelength of 450 nm was measured using a spectrophotometer (product name "UV-2400", manufactured by Shimadzu Corporation). After aging this cured product for 1000 hours in an oven at 120°C, the light transmittance (thickness direction) of the light at a wavelength of 450 nm was measured again. The change was calculated by subtracting the transmittance before and after aging. The results are shown in Table 1 under "Reduction in transmittance due to aging [%]".

[0125] (judgement) Based on the gel time measurement and the results of the decrease in transmittance due to aging, the following judgments were made: ○ Gel time is 850 seconds or less and transmittance decrease due to aging is 10% or less. ×...Other than the above.

[0126] [Table 1]

[0127] [Table 2]

[0128] The components used in the examples and comparative examples are as follows. <Alicyclic epoxy resin (A)> CELLOXIDE2021P: 3,4-epoxycyclohexylmethyl(3,4-epoxy)cyclohexanecarboxylate, manufactured by Daicel Corporation <Other epoxy resins> MA-DGIC: Monoallyl diglycidyl isocyanurate, manufactured by Shikoku Chemical Industry Co., Ltd. X-40-2678: Siloxane derivative with two epoxy groups in the molecule, manufactured by Shin-Etsu Chemical Co., Ltd. <Acid anhydride hardener (B)> MH-700 (Rikacid MH-700): 4-methylhexahydrophthalic anhydride / hexahydrophthalic anhydride = 70 / 30, manufactured by New Japan Chemical Co., Ltd. HN-5700: A mixture of 4-methylhexahydrophthalic anhydride / 3-methylhexahydrophthalic anhydride = 70 / 30 and alicyclic polyester resin, manufactured by Hitachi Chemical Co., Ltd. HN-7200: A mixture of 4-methylhexahydrophthalic anhydride and alicyclic polyester resin, manufactured by Hitachi Chemical Co., Ltd. <Thermal cationic curing catalyst (C)> SI-100L: Product name "San-Aid SI-100L", thermal cationic curing catalyst, manufactured by Sanshin Chemical Industry Co., Ltd. SI-110L: Product name "San-Aid SI-110L", thermal cationic curing catalyst, manufactured by Sanshin Chemical Industry Co., Ltd. <Organic acid metal salts (D)> Zinc octylate: Trade name "Nikka Octix Zinc (15%)", a mineral spirits solution of zinc octylate, manufactured by Nippon Chemical Industries Zinc naphthylate: Trade name "Naphtex Zinc (8%)", a mineral spirits solution of zinc naphthylate, manufactured by Nippon Chemical Industries Zirconium octylate: Product name "17% Octope Zr", 2-ethylhexanoate zirconium, containing 27% ink solvent as a solvent, manufactured by Hope Pharmaceutical Co., Ltd. Calcium octylate: Trade name "5% Octope Ca", calcium 2-ethylhexanoate, containing 21% by weight of 2-ethylhexanoic acid and 38% mineral spirits as a solvent, manufactured by Hope Pharmaceutical Co., Ltd. <Epoxy-acid anhydride curing accelerator> PX-4MP: Product name "Hishicorin PX-4MP", manufactured by Nippon Kagaku Sangyo Co., Ltd. U-CAT 5002: Product name "U-CAT 5002", manufactured by San-Apro Ltd. <Antioxidants (E)> PEP-36: Product name "ADEKA STAB PEP-36", phosphorus-based antioxidant, manufactured by ADEKA Corporation [Industrial Applicability]

[0129] The thermosetting epoxy resin composition of the present invention can be preferably used as a resin composition for sealing optical semiconductors. The thermosetting epoxy resin composition of the present invention can also be used for applications such as adhesives, electrical insulating materials, laminates, coatings, inks, paints, sealants, resists, composite materials, transparent substrates, transparent sheets, transparent films, optical elements, optical lenses, optical members, stereolithography, electronic paper, touch panels, solar cell substrates, optical waveguides, light guide plates, and holographic memories.

Claims

1. A method for producing a curing agent comprising the steps of: (A) an alicyclic epoxy compound; (B) an acid anhydride curing agent; (C) a thermal cationic curing catalyst; (D) one or more compounds selected from the group consisting of organic acid metal salts and metal chelate compounds as a curing accelerator; and (E) a compound represented by the following formula (1): 【Chemistry 1】 [wherein R 1 and R 2 may be the same or different and each represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms] and an alicyclic polyester resin, the content of the acid anhydride curing agent (B) is an amount that is 0.01 to 1.0 equivalent relative to 1 equivalent of epoxy groups in all of the compounds having epoxy groups contained in the thermosetting epoxy resin composition, A thermosetting epoxy resin composition, characterized in that the thermal cationic curing catalyst (C) is at least one selected from the group consisting of aryl diazonium salts, aryl iodonium salts, aryl sulfonium salts, and allene-ion complexes.

2. 2. The thermosetting epoxy resin composition according to claim 1, wherein the curing reaction initiation temperature is 150° C. or lower.

3. 3. The thermosetting epoxy resin composition according to claim 1, wherein the alicyclic epoxy compound (A) is a compound having a cyclohexene oxide group.

4. The alicyclic epoxy compound (A) is represented by the following formula (I-1): 【Chemistry 2】 The thermosetting epoxy resin composition according to any one of claims 1 to 3, wherein the compound is represented by the formula:

5. The thermosetting epoxy resin composition according to any one of claims 1 to 4, further comprising an antioxidant (E).

6. 6. The thermosetting epoxy resin composition according to claim 1, further comprising a siloxane derivative having two or more epoxy groups in the molecule.

7. A cured product of the thermosetting epoxy resin composition according to any one of claims 1 to 6.

8. The thermosetting epoxy resin composition according to any one of claims 1 to 6, which is a resin composition for sealing an optical semiconductor.

9. An optical semiconductor device comprising an optical semiconductor element encapsulated with a cured product of the thermosetting epoxy resin composition according to claim 8.

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