JP4762659B2 - Epoxy resin and epoxy resin composition - Google Patents

Description

  The present invention relates to a novel epoxy resin and a resin composition using the same, and more particularly to an epoxy resin and a resin composition suitable for light-emitting diode (LED) encapsulation.

  Epoxy resins are mainly used in many applications in the paint, civil engineering, and electrical fields because of their excellent electrical properties, adhesiveness, heat resistance, and the like. In particular, aromatic epoxy resins such as bisphenol A type diglycidyl ether, bisphenol F type diglycidyl ether, phenol novolac type epoxy resin, and cresol novolac type epoxy resin have water resistance, adhesiveness, mechanical properties, heat resistance, and electrical insulation. It is widely used in combination with various curing agents because of its excellent economic efficiency. However, since these resins contain an aromatic ring, they are easily deteriorated by ultraviolet rays or the like, and there are restrictions in use in fields where weather resistance and light resistance are required.

  In the field of blue and white LED devices, when an epoxy resin composition containing an aromatic is used as a sealing material, there is a problem that the resin deteriorates due to light emitted from the LED element, yellows with time, and brightness decreases. Has occurred.

Japanese Patent No. 3537119 Japanese Patent No. 3415047 JP-A-9-213997 JP 2000-196151 A JP 2003-277473 A

  Patent Document 1 discloses an epoxy resin composition for electrical / electronic materials containing a hydrogenated epoxy resin obtained by hydrogenating an aromatic epoxy resin and a curing agent. Patent Document 2 discloses a curable epoxy resin composition containing a hydrogenated epoxy resin obtained by hydrogenating an aromatic epoxy, a cycloaliphatic epoxy resin, and a curing agent. Patent Documents 3 and 4 disclose an epoxy resin composition containing an alicyclic epoxy resin obtained by oxidizing a cyclic olefin. Patent Document 5 discloses a hydrogenated epoxy resin having an epoxy equivalent of 230 to 1000 g / eq obtained by hydrogenating an aromatic epoxy resin or a hydrogenated epoxy resin obtained by hydrogenating an aromatic epoxy resin and a polyvalent carboxylic acid. Epoxy resin for LED encapsulation containing an alicyclic epoxy resin obtained by epoxidizing a cyclic olefin with an epoxy resin having an epoxy equivalent of 230 to 1000 g / eq obtained by reaction, an acid anhydride curing agent or a cationic polymerization initiator Compositions have been proposed.

  However, although these resin compositions have a certain effect on light resistance and heat resistance, they have problems in handling such as severe resin shrinkage and cracking of the resin. There is a need for further improvement in heat resistance and light resistance, since yellowing with time due to heat generation at the joint portion and deterioration due to shortening of the emission wavelength are not fully followed.

  In order to solve the above-mentioned problems, the present inventors paid attention to an isocyanuric skeleton having a rigid structure, and made extensive studies. As a result, an epoxy resin obtained by reacting a polyvalent carboxylic acid compound obtained by reacting a specific isocyanuric acid derivative with an acid anhydride with a specific non-aromatic epoxy resin has little curing shrinkage and is transparent. The present invention has been found to provide an epoxy resin composition having excellent properties, light resistance, and low yellowing at high temperatures.

（式中、R₁は炭素数１〜３のアルキレン基を示す。）で表わされるアルコール性水酸基を有するイソシアヌル酸誘導体と、一般式（２）

（式中、R₂及びR₃は水素原子又は炭素数１〜１０のアルキル基を示すが、互いに結合して脂肪族環を形成してもよい。）で表わされる酸無水物とをモル比＝１：２．７〜３．３で反応させて得られる多価カルボン酸化合物であり、
エポキシ樹脂(B)が、３，４−エポキシシクロヘキセニルメチル−３'，４'−エポキシシクロヘキセンカルボキシレートからなるエポキシ樹脂(B1)を３０重量％以上含むエポキシ当量が７０〜３５０g/eqの非芳香族エポキシ樹脂であり、
多価カルボン酸化合物(A)のカルボキシ基１モルに対し、エポキシ樹脂(B)のエポキシ基３．５モル以上、１５モル未満となる割合で反応させて得られるものであることを特徴とする新規エポキシ樹脂である。 That is, the present invention is a novel epoxy resin obtained by reacting a polyvalent carboxylic acid compound (A) and an epoxy resin (B) under a basic catalyst,
The polycarboxylic acid compound (A) is represented by the general formula (1)

(Wherein R ₁ represents an alkylene group having 1 to 3 carbon atoms) and an isocyanuric acid derivative having an alcoholic hydroxyl group represented by the general formula (2)

(Wherein R ₂ and R ₃ represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, but may combine with each other to form an aliphatic ring) and a molar ratio thereof. = 1: A polyvalent carboxylic acid compound obtained by reacting at 2.7 to 3.3,
Non-aromatic epoxy resin (B) containing 30 wt% or more of epoxy resin (B1) comprising 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexenecarboxylate and having an epoxy equivalent of 70 to 350 g / eq Group epoxy resin,
It is obtained by reacting at a ratio of 3.5 mol or more and less than 15 mol of epoxy group of epoxy resin (B) to 1 mol of carboxy group of polyvalent carboxylic acid compound (A). It is a new epoxy resin.

（式中、R₁は炭素数１〜３のアルキレン基を示す。R₂及びR₃は水素原子又は炭素数１から１０のアルキル基を示すが、互いに結合して脂肪族環を形成してもよい。）で表される多価カルボン酸化合物である前記の新規エポキシ樹脂。 The present invention of claim 2 and below is as follows.
2) The polycarboxylic acid compound (A) is represented by the general formula (3)

(In the formula, R ₁ represents an alkylene group having 1 to 3 carbon atoms. R ₂ and R ₃ represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, but are bonded to each other to form an aliphatic ring. The novel epoxy resin which is a polyvalent carboxylic acid compound represented by:

｛式中、Ａは鎖中に炭素環式脂肪族環を有していてもよい炭素数１〜２０のアルキレン基、炭素数１〜６のアルキル基が置換されていてもよい炭素数５〜１０の炭素環式脂肪族環又は一般式（５）

（式中、R₄、R₅は炭素数１〜６のアルキル基を示し、i₄、i₅は０〜４の整数を示し、Xは脂肪族環を有していてもよい炭素数１〜２０のアルキレン基、酸素原子、硫黄原子、又は単結合を示す。）で表される基を示し、脂肪族環は縮環構造を有していてもよく、ｎは０〜３の整数を示す。｝ 3) The epoxy resin (B) comprises an epoxy resin (B2) having an epoxy equivalent of 100 to 400 g / eq represented by the general formula (4) of 30% by weight or more and 70% by weight or less. The new epoxy resin.

{In the formula, A is an alkylene group having 1 to 20 carbon atoms which may have a carbocyclic aliphatic ring in the chain, and an optionally substituted alkyl group having 1 to 6 carbon atoms. 10 carbocyclic aliphatic rings or general formula (5)

(Wherein, R _4, R ₅ represents an alkyl group having 1 to 6 carbon atoms, i _4, i ₅ represents an integer of 0 to 4, X is 1 carbon atoms which may have an aliphatic ring Represents an alkylene group of -20, an oxygen atom, a sulfur atom, or a single bond.), The aliphatic ring may have a condensed ring structure, and n is an integer of 0-3. Show. }

で表される前記の新規エポキシ樹脂。
6） エポキシ樹脂(B1)が、３，４−エポキシシクロヘキセニルメチル−３’，４’−エポキシシクロヘキセンカルボキシレートである前記の新規エポキシ樹脂。 4) In general formula (1), R ₁ is —CH ₂ CH ₂ —, and in general formula (2), R ₂ and R ₃ are bonded together to form —CH ₂ CH ₂ CH ₂ CH ₂ —. The above novel epoxy resin forming a condensed ring.
5) In general formula (4), A represents general formula (6) or general formula (7)

The novel epoxy resin represented by
6) The novel epoxy resin as described above, wherein the epoxy resin (B1) is 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexenecarboxylate.

7) An epoxy resin composition comprising the novel epoxy resin, a curing agent and a curing accelerator.
8) The above epoxy resin composition, wherein the curing agent is an acid anhydride compound and the curing accelerator is an organic phosphine compound.

  Hereinafter, embodiments of the present invention will be described in detail.

  The novel epoxy resin of the present invention (hereinafter referred to as the epoxy resin of the present invention) includes an isocyanuric acid derivative having a terminal alcoholic hydroxyl group represented by the general formula (1) and an acid anhydride represented by the general formula (2). 30% by weight or more of an epoxy resin having an epoxy equivalent of 70 to 250 g / eq obtained by epoxidizing a carbon-carbon double bond of a cyclic olefin with a polycarboxylic acid compound (A) obtained by reacting It is obtained by reacting an epoxy resin (B) having an epoxy equivalent of 70 to 350 g / eq.

In the general formula (1), R ₁ represents an alkylene group having 1 to 3 carbon atoms. Such an isocyanuric acid derivative having R ₁ can be obtained by adding isocyanuric acid and formaldehyde, ethylene oxide, or propylene oxide, but is not limited thereto. Moreover, you may use 2 or more types as needed, unless the range of this invention is impaired. A preferred compound is an isocyanuric acid derivative in which R ₁ is represented by (—CH ₂ CH ₂ —) from the viewpoint of easy availability of raw materials, handling during synthesis, and physical properties when used as an epoxy resin composition.

In the general formula (2), R ₂ and R ₃ represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, but may be bonded to each other to form an aliphatic ring. When R ₂ and R ₃ are bonded to each other to form an aliphatic ring, it is desirable to form a saturated carbon 6-membered ring to form a condensed ring with an adjacent ring. More desirably, it forms —CH ₂ CH ₂ CH ₂ CH ₂ — to form a condensed ring. Such acid anhydrides include, but are not limited to, succinic anhydride, hexahydrophthalic anhydride, methyl hexahydrophthalic anhydride, hydrogenated methyl nadic acid, and the like, and the scope of the present invention is impaired. As long as there is no, you may use 2 or more types as needed. A preferred acid anhydride is hexahydrophthalic anhydride in view of economics and physical properties of the epoxy resin composition.

  In order to obtain the polyvalent carboxylic acid compound (A) by reacting the above isocyanuric acid derivative with an acid anhydride, it can be synthesized by a known method in the same manner as the reaction of a normal alcohol and an acid anhydride. The molar ratio of the isocyanuric acid derivative having an alcoholic hydroxyl group and the acid anhydride is 1: 2.7 to 1: 3.3, preferably 2.9 to 3.3.3, from the viewpoint of heat resistance and light resistance of the cured product. 1 range. This reaction is performed under the condition that a polyvalent carboxylic acid compound that is a monoesterified product of an acid anhydride, that is, a polyvalent carboxylic acid compound represented by the general formula (3) is obtained. For example, this reaction can be performed by mixing an isocyanuric acid derivative and an acid anhydride and stirring at a temperature of 40 to 200 ° C. Below 40 ° C., the reaction rate is slow and not efficient. This reaction theoretically reacts at a ratio of 3 moles of acid anhydride to 1 mole of isocyanuric acid derivative, so that it is desirable to react until either one disappears. When one of them is used excessively, an intermediate or unreacted product may remain, but it may be used in a small amount. Since the main component of this reaction product is the polyvalent carboxylic acid compound represented by the above general formula (3), it is advantageous to use it if it is available.

  In this synthesis reaction, as long as the effects of the present invention are not impaired, one or more known polyhydric alcohols may be used in combination as necessary to obtain a polyvalent carboxylic acid compound (A) as a mixture. However, also in this case, it is preferable to react so that the polyvalent carboxylic acid represented by the general formula (3) is 50 mol% or more.

  Examples of the known polyhydric alcohol include ethylene glycol, propylene glycol, glycerin, pentaerythritol, 1,4-cyclohexanol, 1,4-cyclohexanedimethanol, 4,4′-bicyclohexanedimethanol, hydrogenated bisphenol A, Examples thereof include hydrogenated bisphenol F, 4,4′-bicyclohexanol, but are not limited thereto. However, it is not preferable to use a compound having a carbon-carbon double bond such as bisphenol A, and it is preferable to keep it at 10 mol% or less, preferably 0 or 1 mol% or less.

  The above reaction can be carried out without a solvent, but if necessary, a diluting solvent that does not adversely influence the reaction may be used. Examples of the diluting solvent include aliphatic hydrocarbons such as hexane, heptane, cyclohexane, methylcyclohexane, and ethylcyclohexane, aliphatic ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and cyclopentanone, benzene, and toluene. , Aromatics such as ortho-xylene, meta-xylene, para-xylene, chlorobenzene, dichlorobenzene, aliphatic amides such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, tetrahydrofuran, dioxane, diethylene glycol Examples include ethers such as dimethyl ether and triethylene glycol dimethyl ether. Two or more of these organic solvents may be selected and used as a mixed solvent.

  Next, the polyvalent carboxylic acid compound (A) and the non-aromatic epoxy resin (B) are reacted to obtain the novel epoxy resin of the present invention.

  As the epoxy resin (B), a non-aromatic alicyclic epoxy resin (B1) having an epoxy equivalent of 70 to 250 g / eq obtained by epoxidizing a carbon-carbon double bond of cyclic olefins accounts for 30% by weight or more. Group epoxy resins are used. If the amount of the epoxy resin (B1) used is less than 30% by weight based on the total epoxy resin (B), the heat resistance is deteriorated and the desired effect may not be obtained. This epoxy resin (B1) is an epoxy resin having an alicyclic structure and has at least two epoxy groups. The epoxy resin (B) has an epoxy equivalent (average epoxy equivalent when mixed) of 70 to 350 g / eq.

  Cyclic olefins used as raw materials for the epoxy resin (B1) have at least two carbon-carbon double bonds, of which at least one carbon-carbon double bond is in a ring, and the other is substituted with a ring. It may be a carbon-carbon double bond-containing group such as a vinyl group or an allyl group. Cyclic olefins only need to have at least one olefin ring, and may have a substituent having a double bond as described above. The olefin ring may have a substituent other than a hydrocarbon group such as —COO—. An epoxy resin (B1) is obtained by oxidizing and epoxidizing the carbon-carbon double bond of the cyclic olefins.

  As the epoxy resin (B1), known ones can be used, and preferably 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexenecarboxylate, 1,2: 8,9 diepoxy limonene, 2, Examples include, but are not limited to, 1,2-epoxy-4- (2-oxiranyl) cyclohexane adduct of 2-bis (hydroxymethyl) -1-butanol. The epoxy resin (B1) is contained in an amount of 30 to 100% by weight in the epoxy resin. Moreover, you may use 2 or more types as needed. It is desirable that the alicyclic epoxy resin (B1) contains as little carbon-carbon double bonds as possible. In addition, even when the epoxy resin (B) contains other epoxy resin in addition to the epoxy resin (B1), it is desirable that the other epoxy resin also does not contain a carbon-carbon double bond, and is non-aromatic as a whole. It is good that it is an epoxy resin.

  The epoxy resin (B2) represented by the above formula (4) is preferable as the other epoxy resin in the case of containing other epoxy resins in addition to the epoxy resin (B1). The epoxy equivalent of the epoxy resin (B2) is preferably in the range of 100 to 400 g / eq. The amount of the epoxy resin (B2) used is 70% by weight or less of the epoxy resin (B). Epoxy resin (B1) alone or a combination of epoxy resin (B1) and epoxy resin (B2) is preferred. When used in combination, it is preferable that the epoxy resin (B1) is 30 to 99 wt%, and the epoxy resin (B2) is 1 to 70 wt%. In addition to the epoxy resin (B1) and the epoxy resin (B2), other non-aromatic epoxy resins can be used in a small amount.

As the epoxy resin (B2), a known one can be used as long as it is an epoxy resin represented by the general formula (4). In General formula (4), n represents the integer of 0-3, A is a C1-C20 alkylene group which may have a carbocyclic aliphatic ring in a chain | strand, or C1-C6 Or a group represented by the general formula (5), which may be substituted with a C5-C10 carbocyclic aliphatic ring. The aliphatic ring may have a condensed ring structure. In the general formula (5), i ₄ and i ₅ represent an integer of 0 to 4, R ₄ and R ₅ represent an alkyl group having 1 to 6 carbon atoms, and X contains an aliphatic ring in the chain. Or an alkylene group having 1 to 20 carbon atoms, an oxygen atom, a sulfur atom or a single bond. Preferred A includes a group represented by the above formula (6) or (7).

  Examples of the epoxy resin (B2) represented by the general formula (4) include ethylene glycol, propylene glycol, 1,4-cyclohexanedimethanol, 4,4′-bicyclohexanedimethanol, hydrogenated bisphenol A, and the like. Aromatic ring hydrogenated epoxy resin derived from monocyclic dihydric phenols such as epoxy resin derived from alcoholic hydroxyl group, resorcinol, hydroquinone, 2,5-ditertiarybutylhydroquinone, 1,3 -Nuclear hydrogenation of the aromatic ring of epoxy resin derived from naphthalenediols such as naphthalenediol, 1,4-naphthalenediol, 1,5-naphthalenediol, 1,6-naphthalenediol, 2,7-naphthalenediol 4,4'-isopropylidenediphenol, 4,4'-i Propylidenebis (2-methylphenol), 4,4′-isopropylidenebis (2,6-dimethylphenol), 4,4′-dihydroxydiphenylmethane, 4,4′-dihydroxy-3,3′-dimethyldiphenylmethane, 4, 4′-dihydroxy-3,3 ′, 5,5′-tetramethyldiphenylmethane, 4,4′-secondary butylidenebisphenol, 4,4′-isopropylidenebis (2-tertiarybutylphenol), 4,4′- Cyclohexylidene diphenol, 4,4′-butylidenebis (6-tertiarybutyl-2-methyl) phenol, 4,4 ′-(1-α-methylbenzylidene) bisphenol, 4,4′-dihydroxytetraphenylmethane, α , Α′-bis (4-hydroxyphenyl) -1,4-diiso Propylbenzene, α, α′-bis (4-hydroxy-3-methylphenyl) -1,4-diisopropylbenzene, α, α′-bis (4-hydroxy-3,5-dimethylphenyl) -1,3-dimethyl Benzene, α, α′-bis (4-hydroxy-3,5-dimethylphenyl) -1,4-dimethylbenzene, 4,4′-dihydroxydiphenyl ether, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxy -3-methylphenyl) sulfide, 4,4'-thiobis (2-tertiarybutyl-5-methylphenol), 4,4'-biphenol, 4,4'-dihydroxy-3,3 ', 5,5' -Examples include, but are not limited to, those obtained by nuclear hydrogenation of aromatic rings of epoxy resins derived from bisphenols such as tetramethyldiphenyl. Is not to be done. Two or more types of epoxy resins (B1) and epoxy resins (B2) may be used if necessary.

  The polyvalent carboxylic acid compound (A) and the epoxy resin (B) are reacted in the presence of a basic catalyst to obtain the epoxy resin of the present invention. In this case, the ratio of the polyvalent carboxylic acid compound (A) to the epoxy resin (B) used is that of the epoxy group of the epoxy resin (B) with respect to 1 mol of the carboxy group (—COOH) of the polyvalent carboxylic acid compound (A). It is 3.5 mol or more and less than 15 mol, preferably 5 to 10 mol, more preferably 6 to 8 mol. Here, the calculation of the number of moles of the carboxy group of the polyvalent carboxylic acid compound (A) is calculated when there are three carboxy groups in one molecule of the polyvalent carboxylic acid compound (A). The carboxy group in 1 mol is 3 mol. By performing the reaction at this molar ratio, the epoxy resin of the present invention can be synthesized without causing gelation. When the number of moles of epoxy groups in the epoxy resin (B) is less than 3.5, the resin viscosity increases during the reaction, and the resin causes gelation. On the other hand, when it is 15 or more, curing shrinkage at the time of heat curing becomes large with almost no effect of introducing a polyvalent carboxylic acid compound, which causes difficulty in handling.

  The reaction for synthesizing the epoxy resin of the present invention can be carried out in the absence of a solvent, but the reaction system may be diluted with an organic solvent if necessary, and is not particularly a compound that does not adversely affect the reaction. Not limited. For example, aliphatic ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and cyclopentanone, aromatics such as benzene, toluene, orthoxylene, metaxylene, paraxylene, chlorobenzene and dichlorobenzene, N, N-dimethyl Examples include aliphatic amides such as formamide, N, N-dimethylacetamide, and N-methylpyrrolidone, and ethers such as tetrahydrofuran, dioxane, diethylene glycol dimethyl ether, and triethylene glycol dimethyl ether. Two or more of these organic solvents may be selected and used as a mixed solvent.

  The basic catalyst used in this reaction is selected from the group consisting of tertiary amine compounds, quaternary ammonium compounds, imidazole compounds, tertiary phosphine compounds, quaternary phosphonium compounds, alkali metal hydroxide compounds and alkaline earth metal hydroxide compounds. It is preferable to use at least one compound.

  Tertiary amine compounds include, for example, triethylamine, tri-n-propylamine, triisopropylamine, tri-n-butylamine, tri-sec-butylamine, tri-n-hexylamine, dimethylbenzylamine, diethylbenzylamine, And rebenzylamine, 1,8-diazabicyclo [5.4.0] undec-7-ene, and the like.

  Examples of the quaternary ammonium compound include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetra-n-propylammonium hydroxide, tetra-n-butylammonium hydroxide, trimethylbenzylammonium hydroxide, and triethylbenzylammonium hydroxide. Quaternary ammonium compounds such as tetramethylammonium chloride, tetraethylammonium chloride, tetra-n-propylammonium chloride, tetra-n-butylammonium chloride, trimethylbenzylammonium chloride, triethylbenzylammonium chloride, Tetramethylammonium bromide, tetraethylammonium bromide, tetra-n-propylammonium bromide, tetra-n-butylammonium bromide, trimethylbenzylammonium bromide , Quaternary ammonium bromide compounds such as triethylbenzylammonium bromide, tetramethylammonium iodide, tetraethylammonium iodide, tetra-n-propylammonium iodide, tetra-n-butylammonium iodide, trimethylbenzylammonium iodide And quaternary ammonium iodide compounds such as triethylbenzylammonium iodide.

  Examples of the imidazole compound include 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, 1- (2 ′, 4 ′, 6′-trimethylbenzoyl) -2-ethylimidazole, 1- (2 ′, 6′-dichlorobenzoyl) -2-methylimidazole, 1- (2 ′, 4 ′, 6′-trimethylbenzoyl) -2-methylimidazole, 1- (2 ′, 4 ′, 6 ′ -Trimethylbenzoyl) -2-phenylimidazole and the like.

  Examples of the third phosphine compound include triethylphosphine, tri-n-butylphosphine, triphenylphosphine, trinonylphenylphosphine, and the like. Examples of the quaternary phosphonium compound include quaternary phosphonium compounds such as tetramethylphosphonium hydroxide; tetramethylphosphonium chloride, tetra-n-butylphosphonium chloride, tetraphenylphosphonium chloride, tetra-n-butylphosphonium bromide, Halogenated quaternary phosphonium compounds such as methyltriphenylphosphonium bromide, n-butyltriphenylphosphonium bromide, methyltriphenylphosphonium bromide, ethyltriphenylphosphonium bromide; quaternary phosphonium acetate such as ethyltriphenylphosphonium acetate A compound etc. can be mentioned.

  Examples of the alkali metal hydroxide compound include lithium hydroxide, sodium hydroxide, and potassium hydroxide. Examples of the alkaline earth metal hydroxide include magnesium hydroxide, calcium hydroxide, and barium hydroxide.

  The basic catalysts may be used alone or in advance in a solvent to be dissolved, and then charged into the reaction system. The use ratio of the basic catalyst is usually 0.001 to 10 mol%, preferably 0.05 to 5 mol%, based on 1 mol of the carboxyxyl group of the polyvalent carboxylic acid compound (A).

  Although it does not restrict | limit especially about the temperature conditions in this synthesis reaction, Usually, 20 to 250 degreeC, Preferably it is 50 to 200 degreeC. Below 20 ° C, the reaction is very slow and not economical. Moreover, when it becomes 250 degreeC or more, a raw material and a product raise | generate a side reaction during reaction, and a desired epoxy resin will no longer be obtained.

  The epoxy resin of the present invention comprises (a) a curing agent having reactivity with an epoxy group, and (b) a curing accelerator, and (c) other additives, if necessary. It can be. This epoxy resin composition gives a cured resin excellent in transparency, weather resistance, and heat resistance by heat treatment.

  (A) Various known compounds can be used as the curing agent. For example, organic amine compounds, dicyandiamide and derivatives thereof, imidazoles and derivatives thereof such as 2-methylimidazole and 2-ethyl-4-methylimidazole, bisphenol A, bisphenol F, brominated bisphenol A, naphthalenediol, 4,4′- Dihydric phenol compounds such as biphenol, novolak resin or aralkyl phenol resin obtained by condensation reaction of phenol or naphthols with formaldehyde or xylylene glycols, succinic anhydride, maleic anhydride, phthalic anhydride, hexahydrophthalic anhydride Hydrazide such as methylated hexahydrophthalic anhydride, nadic anhydride, hydrogenated nadic anhydride, trimellitic anhydride, pyromellitic anhydride and other acid anhydride compounds, and adipic hydrazide Can be used ones may be used two or more, if necessary. Among these, an acid anhydride compound, particularly preferably methylated hexahydrophthalic anhydride, is used to reduce curing shrinkage, have transparency, have excellent weather resistance, and have low yellowing at high temperatures. A composition can be obtained.

  (B) Various known compounds can be used as the curing accelerator. Examples include tertiary amines and salts thereof, imidazoles and salts thereof, organic phosphine compounds (meaning including organic phosphines and salts thereof), organic metal salts such as zinc octylate and tin octylate, etc. Two or more types may be used depending on the case. Preferred curing accelerators are tertiary amines and salts thereof, and organic phosphine compounds, and particularly preferred catalysts are organic phosphine compounds.

  (C) Other additives include antioxidants, UV absorbers, other various fillers, film-forming agents, dyes, mold release agents, flow control agents, flame retardants, rubber modifiers, surfactants, reactions Multiple diluents, various oligomers, various polymers and the like can be used.

  In particular, when the epoxy resin composition of the present invention is used as an LED sealing application, it is preferable to add an antioxidant to prevent oxidative deterioration during heating and to obtain a cured product with little coloring.

  Various compounds can be used as the antioxidant. For example, 2,6-tert-butyl-p-cresol, butylated hydroxyanisole, 2,6-tert-butyl-p-ethylphenol, stearyl-β- (3,5-di-tert-butyl-4-4 Monophenols such as -hydroxyphenyl) propionate, 2,2-methylenebis (4-methyl-6-tert-butylphenol), 2,2-methylenebis (4-ethyl-6-tert-butylphenol), 4,4'- Bisphenols such as thiobis (3-methyl-6-tert-butylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl- 2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydro Ciphenyl) propionate] high molecular phenols such as methane, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10- (3,5-di-tert-butyl 4-hydroxybenzyl) Oxaphosphaphenanthrenes such as -9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-decyloxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide And oxides. Two or more of these antioxidants may be used as necessary.

  The epoxy resin composition of the present invention is blended with the component (a) and, if necessary, a desired amount of the components (b) to (c) according to each use known to those skilled in the art. It can be obtained from conditions well known to those skilled in the art.

  Moreover, the epoxy resin of this invention can also be mix | blended with another thermosetting resin system, and can also be used as a high molecular weight polymer composition. Resin used with the epoxy resin of the present invention as a thermosetting resin system includes unsaturated polyester resin, thermosetting acrylic resin, thermosetting amino resin, thermosetting melamine resin, thermosetting urea resin, thermosetting Examples include, but are not limited to, a curable urethane resin, a thermosetting oxetane resin, and a thermosetting epoxy / oxetane composite resin.

  The epoxy resin of the present invention and the epoxy resin composition containing the epoxy resin give a cured product that is transparent and excellent in light resistance, heat resistance, and curing shrinkage resistance. Therefore, the epoxy resin and the epoxy resin composition of the present invention are used in the fields of electronic materials such as paints, coating agents, printing inks, resist inks, adhesives, semiconductor encapsulants, molding materials, casting materials, and electrical insulating materials. Useful. In particular, it is useful in the LED field and is excellent as an epoxy resin composition for LED sealing.

  Next, the present invention will be specifically described based on examples, but the present invention is not limited to the following examples unless it exceeds the gist.

Example 1
(First stage reaction)
Tris (2-hydroxyethyl) isocyanurate (THEIC: Shikoku Kasei Co., Ltd.) 52.3 parts, hexahydrophthalic anhydride (HH: Shin Nippon Rika Co., Ltd.) 92.5 parts, thermometer, cooling The mixture was put into a 1 L four-necked separable flask equipped with a tube, a nitrogen introduction tube, and a stirring blade, and the internal temperature was raised to 160 ° C. using a mantle heater while stirring, and was maintained for 2 hours. When the acid value was not lowered from 235 mg KOH / g, it was judged that the first stage reaction was completed, and 144.8 parts of a polyvalent carboxylic acid compound was obtained. The IR spectrum of this polyvalent carboxylic acid compound is shown in FIG.

(Second stage reaction)
Without removing 144.8 parts of the polyvalent carboxylic acid compound obtained in the first stage reaction, 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexenecarboxylate (Celoxide 2021P: Daicel Chemical Co., Ltd.) 520 parts (6.67 mol of epoxy group to 1 mol of carboxylic acid of polyvalent carboxylic acid) was added and maintained at an internal temperature of 120 ° C., and then triphenylphosphine (TPP: manufactured by Hokuko Chemical Co., Ltd.) was added. After adding 500 ppm with respect to the theoretical resin amount, the internal temperature was raised to 160 ° C. and stirred for 4 hours to complete the second-stage reaction.
630 parts by weight of epoxy resin I was obtained. The epoxy equivalent was 213 g / eq, and the viscosity at 25 ° C. was 930 Pa · s.

Examples 2-5, Comparative Examples 1-5
Epoxy resins II to X were obtained by performing the first-stage reaction and the second-stage reaction under the same conditions as in Synthesis Example 1 except that the amount of raw materials used was as shown in Table 1.

  Table 1 shows the type and amount of raw materials used, the epoxy equivalent of the obtained epoxy resin, and the viscosity (25 ° C.). In addition, since the usage-amount of TPP was unified into 500 ppm, description was abbreviate | omitted. In the tables, numerical units represent parts by weight unless otherwise specified.

Abbreviations or items in the table mean the following.
2021P: Celoxide 2021P
ST-3000: 2,2-bis (4-hydroxycyclohexyl) propanediglycidyl ether (manufactured by Toto Kasei Co., Ltd.), epoxy equivalent 200 g / eq
ZX-1658: 1,4-dimethylolcyclohexane diglycidyl compound (manufactured by Tohto Kasei Co., Ltd.), epoxy equivalent 140 g / eq
(B1) Ratio: Ratio of epoxy resin (B1) in the epoxy resin used in the second-stage reaction Molar ratio: Number of moles of epoxy groups per mole of carboxylic acid groups

Comparative Example 6
The same reaction as in Synthesis Example 1 was performed, except that Celoxide 2021P was changed to 260 parts. Two hours after the introduction of the catalyst, the reaction product was clinging to the stirring blade. The acid value at this time was 15 mgKOH / g, and the reaction was not completed. This resin was immersed in tetrahydrofuran and allowed to stand for a whole day and night, but it did not completely dissolve and swelled, so it was judged that it had gelled.

Examples 6-10, Comparative Examples 7-14
As shown in Table 2, the epoxy resins I to X and the commercially available bisphenol A type epoxy resin YD-012 (manufactured by Tohto Kasei), ST-3000, and ceroxide 2021P were heated to 110 ° C., and Ricacid MH (methyl hexahydro anhydride (Phthalic acid: Shin Nippon Rika Co., Ltd.) was mixed well so that the molar ratio was 1/1, vacuum degassed, and antioxidant (SANKO-HCA: Sanko Co., Ltd.) 0.2 100 parts by weight and a hardening accelerator (PX-4ET: tetra-n-butylphosphonium o, o'-diethyl phosphorodithionate manufactured by Nippon Chemical Industry Co., Ltd.) are added to the mold 100 A resin plate having a thickness of 4 mm was prepared by curing at 140 ° C. for 4 hours and further at 140 ° C. for 12 hours. Table 2 shows the evaluation results of the glass transition temperature, initial transmittance, heat resistance, and light resistance of the obtained cured product.

Measurement of glass transition temperature (Tg) of cured product The glass transition temperature of the cured product was measured using a differential scanning calorimeter DELTA SERIES DSC7 manufactured by PerkinElmer. The heating rate was 10 ° C./min.

Initial transmittance of cured product Using a self-recording spectrophotometer U-3410 manufactured by Hitachi, Ltd., a transmittance of 400 nm of a cured product having a thickness of 4 mm was measured.

Measurement of heat resistance After holding the cured product at 150 ° C. for 72 hours in air, the transmittance at 400 nm was measured in the same manner as the initial transmittance.

Measurement of light resistance Using a weather resistance tester QUV manufactured by Q Panel Co., Ltd., the 400 nm transmittance after UV irradiation for 600 hours was measured in the same manner as the initial transmittance. A UVA of 340 nm was used for the QUV lamp, and the black panel temperature was 55 ° C.

Presence / absence of change in shape of cured product due to cure shrinkage When the mold was removed, the shape change of the cured product due to cure shrinkage was visually determined. ○: The shape of the mold is maintained. (Triangle | delta): Although the shape of a metal mold | die is maintained, the crack has arisen in hardened | cured material. X: The shape of the mold was not maintained and the resin was cracked.

IR spectrum of polycarboxylic acid compounds

Claims (7)

A novel epoxy resin obtained by reacting a polyvalent carboxylic acid compound (A) and an epoxy resin (B) under a basic catalyst,
The polycarboxylic acid compound (A) is represented by the general formula (1)

(Wherein R ₁ represents an alkylene group having 1 to 3 carbon atoms) and an isocyanuric acid derivative having an alcoholic hydroxyl group represented by the general formula (2)

(Wherein R ₂ and R ₃ represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, but may combine with each other to form an aliphatic ring) and a molar ratio thereof. = 1: A polyvalent carboxylic acid compound obtained by reacting at 2.7 to 3.3,
Non-aromatic epoxy resin (B) containing 30 wt% or more of epoxy resin (B1) comprising 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexenecarboxylate and having an epoxy equivalent of 70 to 350 g / eq Group epoxy resin,
A novel epoxy obtained by reacting with 1 mol of the carboxy group of the polycarboxylic acid compound (A) at a ratio of 3.5 to less than 15 mol of the epoxy group of the epoxy resin (B) resin. The polycarboxylic acid compound (A) is represented by the general formula (3)

(In the formula, R ₁ represents an alkylene group having 1 to 3 carbon atoms. R ₂ and R ₃ represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, but are bonded to each other to form an aliphatic ring. The novel epoxy resin according to claim 1, which is a polyvalent carboxylic acid compound represented by: The epoxy resin (B) comprises an epoxy resin (B2) having an epoxy equivalent of 100 to 400 g / eq represented by the general formula (4) of 30% by weight or more and 70% by weight or less. The novel epoxy resin as described in 1 or 2.

{In the formula, A is an alkylene group having 1 to 20 carbon atoms which may have a carbocyclic aliphatic ring in the chain, and an optionally substituted alkyl group having 1 to 6 carbon atoms. 10 carbocyclic aliphatic rings or general formula (5)

(Wherein, R _4, R ₅ represents an alkyl group having 1 to 6 carbon atoms, i _4, i ₅ represents an integer of 0 to 4, X is 1 carbon atoms which may have an aliphatic ring Represents an alkylene group of -20, an oxygen atom, a sulfur atom, or a single bond.), The aliphatic ring may have a condensed ring structure, and n is an integer of 0-3. Show. } In the general formula (1), R ₁ is —CH ₂ CH ₂ —, and in the general formula (2), R ₂ and R ₃ are bonded to each other to form —CH ₂ CH ₂ CH ₂ CH ₂ —. The novel epoxy resin of Claim 1 or 3 which forms. In general formula (4), A represents general formula (6) or general formula (7).

The novel epoxy resin of Claim 3 or 4 which is group represented by these. The epoxy resin composition characterized by including the novel epoxy resin in any one of Claims 1-5, a hardening | curing agent, and a hardening accelerator. The epoxy resin composition according to claim 6, wherein the curing agent is an acid anhydride compound and the curing accelerator is an organic phosphine compound.

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