JP5179839B2 - Epoxy resin composition and cured product thereof - Google Patents

Description

  The present invention relates to an epoxy resin composition, more specifically, an alicyclic epoxy resin containing a specific ratio of an alicyclic epoxy resin that is liquid at 25 ° C. and an alicyclic epoxy resin that is solid at 25 ° C. The present invention relates to an alicyclic epoxy resin mixture having a specific viscosity at 45 ° C., an epoxy resin composition containing an acid anhydride and a dicarboxylic acid, and a cured product thereof. The epoxy resin composition and cured product thereof are for coating materials, adhesives, photocurable materials, and optical / electronics related to optical semiconductors such as light receiving elements such as LEDs (light emitting diodes) and CCDs (charge coupled devices). It is useful in various fields including applications such as sealing materials.

  Light emitting devices such as optical semiconductors that are put to practical use in various indoor and outdoor display boards, image reading light sources, traffic signals, large display units, etc., mainly protect the periphery of the light emitter by epoxy resin sealing. ing. As an epoxy resin used as a sealing agent, an aromatic epoxy resin such as bisphenol A is generally used, and an alicyclic acid anhydride is widely used as a curing agent.

  In recent years, high output, blueening, and whitening of LED elements have been rapidly developed, and light emission with a relatively short wavelength and high output has come to be performed, and is sealed with the above-described aromatic epoxy resin. When stopped, the aromatic ring absorbs light of a short wavelength, so that the resin used as the sealing agent is deteriorated, and there is a problem that the yellowing causes a decrease in luminance and a color change occurs.

  Then, LED sealed using the liquid alicyclic epoxy resin obtained by oxidizing a cyclic olefin is proposed (refer patent documents 1 and 2). However, the cured product of this alicyclic epoxy resin is vulnerable to various stresses, and is susceptible to cracking due to cold cycles (repeating heating and cooling), etc., so it has low thermal shock resistance and is a liquid alicyclic epoxy resin. Independently, it was unsuitable for the use which seals an LED element.

  Therefore, liquid nuclear hydrogenated bisphenol A type epoxy resin hydrogenated with aromatic ring is mainly used, alicyclic epoxy resin and phosphorus antioxidant are blended, and methylhexahydrophthalic anhydride is used as a curing agent. A sealed LED has been proposed (see Patent Document 3). However, although the alicyclic epoxy resin is excellent in colorless transparency, the strength of the cured product is insufficient and the thermal shock resistance) is low, and it cannot be said that it is suitable as a sealant for LED elements.

  On the other hand, the properties of the bisphenol A type epoxy resin as a sealing material are excellent except that the cured product is colored. In order to take advantage of this property, a nuclear hydrogenated bisphenol A type epoxy resin having a high epoxy equivalent has been proposed. (See Patent Document 4). However, the epoxy resin is solid at 25 ° C. and is difficult to use as a sealant. Furthermore, the glass transition temperature of the cured product is low, making it unsuitable for use in high brightness blue or white LEDs.

JP-A-9-213997 JP 2000-196151 A JP 2003-12896 A JP 2005-120357 A

  Accordingly, an object of the present invention is to provide an epoxy resin composition that is colorless and transparent and excellent in strength, heat resistance, light resistance, heat deterioration resistance, and thermal shock resistance. Still another object of the present invention is to cure an epoxy resin obtained by curing the epoxy resin composition, an optical semiconductor device using the epoxy resin composition as a sealing agent, and an adhesive comprising the epoxy resin composition. Is to provide.

  As a result of intensive studies to solve the above problems, the present inventor has a liquid alicyclic epoxy resin having a specific structure and a viscosity at 25 ° C. of 1000 mPa · s or less, and a solid at 25 ° C. Epoxy resin composition containing an alicyclic epoxy resin mixture having a specific ratio and having a viscosity at 45 ° C. of 60000 mPa · s or less, an acid anhydride, and a dicarboxylic acid, The present inventors have found that a cured product that is colorless and transparent and excellent in strength, heat resistance, light resistance, heat deterioration resistance, and thermal shock resistance can be obtained by curing.

（式（３ｇ）中、ｎは１〜３０の整数を示す。）
で表される脂環式エポキシ樹脂から選択される少なくとも１種である脂環式エポキシ樹脂Ａと、ビスフェノールＡ型エポキシ樹脂又はビスフェノールＦ型エポキシ樹脂を核水素化して得られる２５℃で固体の脂環式エポキシ樹脂Ｂとを、Ａ／Ｂ（重量比）＝３５／６５〜９５／５の割合で含む混合物であって、４５℃における粘度が６００００ｍＰａ・ｓ以下である脂環式エポキシ樹脂混合物と、２５℃における粘度が５００ｍＰａ・ｓ以下の酸無水物とジカルボン酸を含有し、
前記ジカルボン酸が、下記式（２）

（式中、Ｒ ¹ 〜Ｒ ⁸ は、同一又は異なって、水素原子、メチル基、又は、エチル基を示す。Ｘは、炭素数３〜２０の２価の環状炭化水素基、又は、炭素数２〜２０の２価の直鎖状、分岐鎖状、若しくは、炭素数３〜２０の２価の環状炭化水素基の２以上が酸素原子を介して若しくは介することなく結合した総炭素数が４〜２２の環状脂肪族骨格を含む２価の基を示す）
で表される環状脂肪族骨格を有するジカルボン酸であるエポキシ樹脂組成物を提供する。 That is, the present invention provides the following formulas (3a) to (3g)

(In the formula (3g), n represents an integer of 1 to 30.)
Solid fat at 25 ° C. obtained by nuclear hydrogenation of alicyclic epoxy resin A, which is at least one selected from alicyclic epoxy resins represented by the following formula , and bisphenol A type epoxy resin or bisphenol F type epoxy resin A mixture containing cyclic epoxy resin B at a ratio of A / B (weight ratio) = 35/65 to 95/5, and an alicyclic epoxy resin mixture having a viscosity at 45 ° C. of 60000 mPa · s or less An acid anhydride having a viscosity at 25 ° C. of 500 mPa · s or less and a dicarboxylic acid ,
The dicarboxylic acid is represented by the following formula (2)

(In formula, R < ¹ > -R < ⁸ > is the same or different, and shows a hydrogen atom, a methyl group, or an ethyl group. X is a C3-C20 bivalent cyclic hydrocarbon group or carbon number. 2 to 20 divalent linear, branched, or 2 or more of divalent cyclic hydrocarbon groups having 3 to 20 carbon atoms bonded to each other with or without oxygen atoms. A divalent group containing a cyclic aliphatic skeleton of ˜22)
An epoxy resin composition which is a dicarboxylic acid having a cycloaliphatic skeleton represented by the formula:

  The epoxy resin composition preferably contains an antioxidant and / or an ultraviolet absorber.

  Furthermore, this invention provides the optical semiconductor device sealed using the said epoxy resin composition.

［式中、Ｙは単結合、メチルメチレン基（−ＣＨ（ＣＨ ₃ ）−）、エチレン基（−ＣＨ ₂ ＣＨ ₂ −）、メチルエチレン基（−ＣＨ ₂ ＣＨ（ＣＨ ₃ ）−）、プロピレン基（−ＣＨ ₂ ＣＨ ₂ ＣＨ ₂ −）、炭素数４〜１８の直鎖状又は分岐鎖状のアルキレン基、２価の脂環式炭化水素基、−Ｃ（＝Ｏ）Ｏ−、−ＣＯ−、又は、２価の炭化水素基の１又は２以上と−Ｃ（＝Ｏ）Ｏ−、−ＣＯ−、又は−Ｏ−のうち少なくとも１つが結合した２価の複素環基を示す。また、シクロヘキサン環にはアルキル基が結合していてもよい］
で表される脂環式エポキシ樹脂、又は、分子内に環状脂肪族骨格及び２つ以上のエポキシ基を有し、且つ、２つ以上のエポキシ基のうち、１つのみが環状脂肪族骨格を構成する２つの炭素原子を含有している脂環式エポキシ樹脂であって、２５℃における粘度が１０００ｍＰａ・ｓ以下の脂環式エポキシ樹脂Ａと、芳香族エポキシ樹脂を核水素化して得られる２５℃で固体の脂環式エポキシ樹脂Ｂとを、Ａ／Ｂ（重量比）＝３５／６５〜９５／５の割合で含む混合物であって、４５℃における粘度が６００００ｍＰａ・ｓ以下である脂環式エポキシ樹脂混合物と、２５℃における粘度が５００ｍＰａ・ｓ以下の酸無水物とジカルボン酸を含有するエポキシ樹脂組成物についても説明する。 Furthermore, the present invention provides an adhesive comprising the epoxy resin composition. Further, in the present specification, the following formula (1)

[Wherein Y represents a single bond, a methylmethylene group (—CH (CH ₃ ) —), an ethylene group (—CH ₂ CH ₂ —), a methylethylene group (—CH ₂ CH (CH ₃ ) —), a propylene group. (—CH ₂ CH ₂ CH ₂ —), a linear or branched alkylene group having 4 to 18 carbon atoms, a divalent alicyclic hydrocarbon group, —C (═O) O—, —CO—. Or a divalent heterocyclic group in which one or more of divalent hydrocarbon groups and at least one of -C (= O) O-, -CO-, or -O- are bonded. In addition, an alkyl group may be bonded to the cyclohexane ring.
Or a cycloaliphatic skeleton and two or more epoxy groups in the molecule, and only one of the two or more epoxy groups has a cycloaliphatic skeleton. 25. An alicyclic epoxy resin containing two constituting carbon atoms, which is obtained by nuclear hydrogenation of an alicyclic epoxy resin A having a viscosity at 25 ° C. of 1000 mPa · s or less and an aromatic epoxy resin. And a cycloaliphatic epoxy resin B solid at a temperature of A / B (weight ratio) = 35/65 to 95/5, and a viscosity at 45 ° C. of 60000 mPa · s or less. An epoxy resin composition containing a formula epoxy resin mixture, an acid anhydride having a viscosity at 25 ° C. of 500 mPa · s or less, and a dicarboxylic acid will also be described.

  By curing the epoxy resin composition of the present invention, a cured product that is colorless and transparent and has excellent strength, heat resistance, light resistance, heat deterioration resistance, and thermal shock resistance can be obtained. Can be suitably used in various fields including applications such as sealing materials for electrical and electronic related to optical semiconductors.

[Epoxy resin composition]
The epoxy resin composition according to the present invention has an alicyclic epoxy resin represented by the formula (1) or a cyclic aliphatic skeleton and two or more epoxy groups in the molecule, and two or more epoxies. An alicyclic epoxy resin in which only one of the groups is formed to contain two carbon atoms constituting a cycloaliphatic skeleton, and the viscosity at 25 ° C. is 1000 mPa · s or less. A and a cycloaliphatic epoxy resin B solid at 25 ° C. obtained by nuclear hydrogenation of an aromatic epoxy resin at a ratio of A / B (weight ratio) = 35/65 to 95/5. And an alicyclic epoxy resin mixture having a viscosity at 45 ° C. of 60000 mPa · s or less, an acid anhydride having a viscosity at 25 ° C. of 500 mPa · s or less, and a dicarboxylic acid.

  The alicyclic epoxy resin A has an alicyclic epoxy resin represented by the formula (1) or a cyclic aliphatic skeleton and two or more epoxy groups in the molecule, and two or more epoxy groups. Among them, only one is an alicyclic epoxy resin containing two carbon atoms constituting a cycloaliphatic skeleton, and the viscosity at 25 ° C. is 1000 mPa · s or less.

In the alicyclic epoxy resin represented by the formula (1), Y represents a single bond, a methylmethylene group (—CH (CH ₃ ) —), an ethylene group (—CH ₂ CH ₂ —), a methylethylene group (— _{CH 2 CH (CH 3) -} ), propylene _{(-CH 2 CH 2 CH 2 -} ), a linear or branched alkylene group having 4 to 18 carbon atoms, divalent alicyclic hydrocarbon group, At least one of —C (═O) O—, —CO—, or one or more of divalent hydrocarbon groups and —C (═O) O—, —CO—, or —O— is bonded. The divalent heterocyclic group. In addition, an alkyl group may be bonded to the cyclohexane ring.

  Examples of the linear or branched alkylene group having 4 to 18 carbon atoms include a tetramethylene group and a hexamethylene group. Examples of the divalent alicyclic hydrocarbon group include 1,2-cyclopentylene, 1,3-cyclopentylene, cyclopentylidene, 1,2-cyclohexylene, 1,3-cyclohexylene, And divalent cycloalkylene groups (including cycloalkylidene groups) such as 1,4-cyclohexylene and cyclohexylidene groups. Examples of the divalent hydrocarbon group in which one or more of the divalent hydrocarbon groups and at least one of -C (= O) O-, -CO-, or -O- are bonded include, for example, a methylene group, A linear or branched alkylene group having 1 to 18 carbon atoms (preferably 1 to 10 carbon atoms is preferred) such as an ethylene group, a methylethylene group, a propylene group, a butylene group or a pentylene group; An alicyclic hydrocarbon group (in particular, a divalent cycloalkylene group is preferable). Moreover, as an alkyl group which may be couple | bonded with the cyclohexane ring, C1-C6 linear, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, t-butyl group, or, for example, And a branched alkyl group. Of these, a methyl group is preferable. The number of alkyl groups that may be bonded to the cyclohexane ring is about 0 to 3.

  Representative examples of the alicyclic epoxy resin represented by the formula (1) include compounds represented by the following formulas (3a) to (3g). In the following formula, n represents an integer of 1 to 30.

  Fat having a cycloaliphatic skeleton and two or more epoxy groups in the molecule, and only one of the two or more epoxy groups includes two carbon atoms constituting the cycloaliphatic skeleton A representative example of the cyclic epoxy resin includes a compound represented by the following formula (4).

  As alicyclic epoxy resin A, the viscosity in 25 degreeC is 1000 mPa * s or less (for example, 100-1000 mPa * s), Especially, 200-800 mPa * s is preferable. As alicyclic epoxy resin A, the alicyclic epoxy resin mentioned by said Formula (3) or Formula (4) can be used individually or in combination of 2 or more types. Especially, as alicyclic epoxy resin A, the alicyclic epoxy resin represented by the said Formula (3b) is preferable.

  The alicyclic epoxy resin A can be synthesized by a known and commonly used method. For example, the alicyclic epoxy resin A can be synthesized by epoxidizing a corresponding alicyclic olefin compound (cyclic olefin compound) with an aliphatic percarboxylic acid (for example, peracetic acid). In this case, those synthesized using a substantially anhydrous aliphatic percarboxylic acid are preferable in that they have a high epoxidation rate (see JP-A-2002-275169). Further, as the alicyclic epoxy resin A, trade names “CEL-2021P”, “GT-401”, “GT-403”, “GT-301”, “GT-302” (manufactured by Daicel Chemical Industries), etc. It is also possible to use commercially available products.

  In the present invention, together with the alicyclic epoxy resin A, an alicyclic epoxy resin in which an epoxy group is formed without sharing the carbon atoms constituting the cycloaliphatic skeleton may be used. Examples of the alicyclic epoxy resin in which the epoxy group is formed without sharing the carbon atoms constituting the cycloaliphatic skeleton include, for example, trade names “YX-8000”, “YX-8034” (Japan Epoxy Resin Co., Ltd.). ), Trade name “HBE-100” (manufactured by Shinnippon Rika Co., Ltd.), and trade name “ST-3000” (manufactured by Tohto Kasei Co., Ltd.); And diglycidyl ether of cyclohexanedimethanol such as Rika Co.). The mixing ratio of the alicyclic epoxy resin in which the epoxy group is formed without sharing the carbon atoms constituting the cycloaliphatic skeleton is about 5 to 50 parts by weight with respect to 100 parts by weight of the alicyclic epoxy resin A. is there.

（式中、ｍは自然数を示す）
で表される芳香族エポキシ樹脂を核水素化して得られる脂環式エポキシ樹脂が好ましい。脂環式エポキシ樹脂Ｂは、前記脂環式エポキシ樹脂を単独で、又は、２種以上を組み合わせて使用することができる。 The alicyclic epoxy resin B in the present invention is an alicyclic epoxy resin having excellent transparency and is a solid alicyclic epoxy resin obtained at 25 ° C. obtained by nuclear hydrogenation of an aromatic epoxy resin. There is no particular limitation. For example, an alicyclic epoxy resin obtained by nuclear hydrogenation of a bisphenol A type epoxy resin or a bisphenol F type epoxy resin, or a nuclear hydrogenated bisphenol A type epoxy resin in a large amount of 2 or more with carboxylic acid. An alicyclic epoxy resin formed into a body is mentioned, and among them, an alicyclic epoxy resin obtained by multimerizing two or more nuclear hydrogenated bisphenol A type epoxy resins with a carboxylic acid is preferable. In particular, the following formula (5)

(Where m represents a natural number)
An alicyclic epoxy resin obtained by nuclear hydrogenation of an aromatic epoxy resin represented by The alicyclic epoxy resin B can be used alone or in combination of two or more.

  The epoxy equivalent of the alicyclic epoxy resin B is, for example, 500 to 5000, preferably 550 to 4500, and particularly preferably about 600 to 4000. The nuclear hydrogenation rate of the alicyclic epoxy resin B is preferably 96% or more, and particularly preferably 98% or more when stability to light is required. The upper limit of the nuclear hydrogenation rate is 100%. When the nuclear hydrogenation rate is less than 96%, for example, when the epoxy resin according to the present invention is used for sealing a nitride semiconductor LED, the resin deteriorates with time by absorbing light of a short wavelength, In some cases, yellowing may significantly reduce the luminance.

  Moreover, as a softening temperature of the alicyclic epoxy resin B, it is 60-150 degreeC, for example, Preferably, it is about 65-140 degreeC. When the softening temperature is less than 60 ° C., stickiness and fusion are likely to occur, and workability may be reduced. On the other hand, when the softening temperature exceeds 150 ° C., it is necessary to dissolve the alicyclic epoxy resin B at a high temperature when mixing with other epoxy resins or curing agents, and workability and economy may be reduced. . The softening temperature of the alicyclic epoxy resin B can be appropriately adjusted by adjusting the epoxy equivalent of the epoxy resin to be constituted. For example, when the alicyclic epoxy resin B contains a high molecular weight aromatic epoxy resin having a large epoxy equivalent, the softening temperature can be further increased.

  The light transmissivity of the alicyclic epoxy resin B at a wavelength of 400 nm is, for example, preferably 85% or more, particularly 90% or more in the alicyclic epoxy resin B (thickness 1 mm). If the light transmittance is less than 85%, the transparency of the resulting cured epoxy resin is lowered, which may be unsuitable for optical materials.

  The alicyclic epoxy resin B in the present invention can be synthesized by a known and commonly used method, for example, a method described in JP-A-2005-120357. That is, an aromatic epoxy resin (particularly a bisphenol A type epoxy resin) having an epoxy equivalent of 500 to 10,000 (preferably 600 to 6000) and a total content of alkali metal elements and group 15 elements of the periodic table of 10 ppm by weight or less. And / or bisphenol F-type epoxy resin) can be synthesized by nuclear hydrogenation in the presence of a catalyst containing a transition element compound (for example, a platinum compound).

（式中、Ｒは、水素原子、又は、炭素数１〜３のアルキル基を示し、ｐは、自然数を示す）
で表される２５℃で固体の脂環式エポキシ樹脂（商品名「ＥＨＰＥ−３１５０」、ダイセル化学工業社製）等の市販品を使用することもできる。 Furthermore, as the alicyclic epoxy resin B, the trade name “YL-7170” (manufactured by Japan Epoxy Resin Co., Ltd.), the trade name “ST-4000” (manufactured by Tohto Kasei Co., Ltd.), the following formula (6)

(In the formula, R represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and p represents a natural number.)
Commercially available products such as a solid alicyclic epoxy resin (trade name “EHPE-3150”, manufactured by Daicel Chemical Industries, Ltd.) at 25 ° C.

  In the epoxy resin composition of the present invention, the ratio of the alicyclic epoxy resin A and the alicyclic epoxy resin B is within the range of A / B (weight ratio) = 35/65 to 95/5. Contains a resin mixture. When the ratio of the alicyclic epoxy resin A and the alicyclic epoxy resin B is less than 35/65, the glass transition temperature of the cured epoxy resin becomes too low, and the light resistance and heat deterioration resistance may decrease. Moreover, since the alicyclic epoxy resin composition becomes highly viscous or solid at 45 ° C., it may be unsuitable as a casting material. On the other hand, if the ratio of the alicyclic epoxy resin A and the alicyclic epoxy resin B exceeds 95/5, the thermal shock resistance of the cured epoxy resin is lowered, and cracks are likely to occur due to a cooling / heating cycle or the like. is there.

  The epoxy resin composition of the present invention may contain an epoxy compound other than the alicyclic epoxy resin A and the alicyclic epoxy resin B of the present invention. In this case, the content of the alicyclic epoxy resin A and the alicyclic epoxy resin B in the epoxy resin composition of the present invention is usually 50 with respect to the entire alicyclic epoxy resin contained in the epoxy resin composition. % By weight or more, preferably 70% by weight or more, more preferably 90% by weight or more, particularly preferably 95% or more, and the alicyclic epoxy resin is composed only of the alicyclic epoxy resin A and the alicyclic epoxy resin B. May be.

  The viscosity at 45 ° C. of the alicyclic epoxy resin mixture contained in the epoxy resin composition of the present invention is 60000 mPa · s or less, for example, in the range of 1000 to 60000 mPa · s. When the viscosity exceeds 60000 mPa · s, the viscosity of the epoxy resin composition becomes too high, the handleability decreases, and it may be unsuitable as a casting material. On the other hand, if the viscosity is less than 1000 mPa · s, it takes time to cure and the workability may be lowered.

  The acid anhydride having a viscosity at 25 ° C. of 500 mPa · s or less contained in the epoxy resin composition of the present invention has a function as a curing agent. Examples of the acid anhydride having a viscosity at 25 ° C. of 500 mPa · s or less include tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylendoethylenetetrahydrophthalic anhydride, Mention may be made of cyclic aliphatic acid anhydrides such as trialkyltetrahydrophthalic anhydride. Among these, hydrogenated cycloaliphatic acid anhydrides such as hexahydrophthalic anhydride and methylhexahydrophthalic anhydride can be preferably used in that the light resistance of the epoxy resin composition is improved. . In addition, aromatic acid anhydrides such as phthalic anhydride, trimellitic anhydride, pyromellitic anhydride and the like are not preferable because coloration easily occurs in the cured epoxy resin. As the acid anhydride having a viscosity at 25 ° C. of 500 mPa · s or less, the cyclic aliphatic acid anhydride can be used alone or in combination of two or more.

  The amount of the acid anhydride having a viscosity at 25 ° C. of 500 mPa · s or less is, for example, 50 to 120 parts by weight with respect to 100 parts by weight of the alicyclic epoxy resin mixture in the epoxy resin composition according to the present invention. The amount is preferably about 60 to 110 parts by weight. If the amount is less than 50 parts by weight based on 100 parts by weight of the alicyclic epoxy resin mixture, the curability may be insufficient. If it exceeds 120 parts by weight with respect to 100 parts by weight of the alicyclic epoxy resin mixture, the balance of hue, heat resistance and moisture resistance of the cured epoxy resin may be impaired, which is not preferable.

In addition to the acid anhydride having a viscosity at 25 ° C. of 500 mPa · s or less, the epoxy resin composition according to the present invention may be used in combination with other curing agents as necessary. Other curing agents include, for example, amine BF ₃ complex compounds; Bronsted acid salts such as aliphatic sulfonium salts, aromatic sulfonium salts, iodonium salts, and phosphonium salts; adipic acid; sebacic acid; terephthalic acid; Acid; polycarboxylic acids such as carboxyl group-containing polyesters; Phenol resins, resols, and amine curing agents are not preferred because the epoxy resin cured product is colored yellow or red. Also, organic acid hydrazides such as dicyandiamides, adipic acid dihydrazide and phthalic acid dihydrazide are not preferable because of their low reactivity with liquid alicyclic epoxy resins. The amount of the other curing agent used is, for example, about 1 to 10 parts by weight with respect to 100 parts by weight of the acid anhydride having a viscosity at 25 ° C. of 500 mPa · s or less.

  Moreover, you may use a hardening accelerator with the said hardening | curing agent for the epoxy resin composition of this invention. Examples of the curing accelerator include benzyldimethylamine, 2,4,6-tris (dimethylaminomethyl) phenol, 1,8-diazabicyclo [5.4.0] undecene-7, 1,5-azabicyclo [4. 3.0] tertiary amines such as nonene and salts thereof; phosphonium salts, imidazoles, organic phosphine compounds or salts thereof; metal soaps such as zinc octylate and tin octylate; chelate compounds such as aluminum and titanium Is mentioned. A hardening accelerator can be used individually or in combination of 2 or more types.

  As the usage-amount of the said hardening accelerator, it is 0.1-5 weight part with respect to 100 weight part of alicyclic epoxy resin mixtures in the epoxy resin composition based on this invention, Preferably, 0.2- About 2 parts by weight. If the amount of the curing accelerator used is less than 0.1 parts by weight or more than 5 parts by weight, the balance of hue, heat resistance and moisture resistance of the cured epoxy resin is impaired, which is not preferable.

  The epoxy resin composition according to the present invention is further characterized in that dicarboxylic acid is added as a curing agent. The dicarboxylic acid contained in the epoxy resin composition of the present invention is not particularly limited as long as it is soluble in an acid anhydride having a viscosity at 25 ° C. of 500 mPa · s or less. It can synthesize | combine by making the acid anhydride which has and the compound which has a 2-4 functional alcoholic hydroxyl group react. By adding dicarboxylic acid, the curing reaction of the epoxy resin composition can be allowed to proceed slowly, and the transparency, strength, heat resistance, and heat deterioration resistance of the cured epoxy resin obtained by curing the epoxy resin composition , Light resistance and thermal shock resistance can be improved.

The dicarboxylic acid is preferably a bifunctional to tetrafunctional dicarboxylic acid, and more preferably a bifunctional dicarboxylic acid. As the dicarboxylic acid in the present invention, a dicarboxylic acid having a cycloaliphatic skeleton represented by the above formula (2) can be preferably used. In formula (2), R < ₁ > -R < ₈ > is the same or different and shows a hydrogen atom, a methyl group, or an ethyl group. X is a divalent linear or branched chain having 2 to 20 carbon atoms, or a divalent cyclic hydrocarbon group having 3 to 20 carbon atoms, or two or more of these are through or through an oxygen atom. A divalent group having 4 to 22 total carbon atoms bonded together.

  In X, examples of the divalent linear hydrocarbon group having 2 to 20 carbon atoms include methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, undecylene, pentadecylene, and octadecylene groups. It is done.

  In X, examples of the divalent branched hydrocarbon group having 2 to 20 carbon atoms include methylmethylene, methylethylene, dimethylmethylene, 2-methylpropylene, 2,2-dimethylpropylene, 2-methylbutylene, 2,3-dimethylbutylene, 2,2-dimethylbutylene, 2-ethyl-2-methylpropylene, 2-methylpentylene, 2,2-dimethylpentylene, 2,3-dimethylpentylene, 2,4-dimethyl Pentylene, 2,3,4-trimethylpentylene, 2-ethyl-2-methylpentylene group, etc. are mentioned.

  In X, examples of the divalent cyclic hydrocarbon group having 3 to 20 carbon atoms include 1,2-cyclopentylene, 1,3-cyclopentylene, cyclopentylidene, 1,2-cyclohexylene, 1,3-cyclohexylene, 1,4-cyclohexylene, cyclohexylidene group and the like can be mentioned.

  Examples of the acid anhydride having a cycloaliphatic skeleton, which is a raw material for the synthesis of dicarboxylic acid, are the same examples as the cycloaliphatic acid anhydrides mentioned in the above examples of acid anhydrides having a viscosity at 25 ° C. of 500 mPa · s or less. Can be mentioned. Of these, hexahydrophthalic anhydride and methylhexahydrophthalic anhydride are preferably used in the present invention.

  Examples of the compound having a di- to tetra-functional alcoholic hydroxyl group, which is a dicarboxylic acid synthesis raw material, include divalent to tetravalent aliphatic alcohols and divalent to tetravalent alcohols containing a cyclic aliphatic skeleton. Examples of the divalent to tetravalent aliphatic alcohol include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,10-decanediol, neo Examples include pentyl glycol, glycerin, trimethylol propane, and dimethylol propane. Examples of the divalent to tetravalent alcohol containing a cyclic aliphatic skeleton include 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, hydrogenated bisphenol F, and the like. In the present invention, among these, divalent to tetravalent alcohols containing a cyclic aliphatic skeleton are preferably used.

  The reaction between the acid anhydride having a cyclic aliphatic skeleton and the compound having a bifunctional to tetrafunctional alcoholic hydroxyl group in dicarboxylic acid synthesis is preferably performed in a solvent. Examples of the solvent used in the reaction include toluene, xylene, pseudocumene, cumene, hexane, octane, undecane, dodecane, methyl ethyl ketone, and methyl isobutyl ketone. In addition, when the acid anhydride having a cyclic skeleton is in a liquid state, the acid anhydride can be used as a solvent. In that case, it is not necessary to use a separate solvent.

  The reaction temperature between the acid anhydride having a cyclic aliphatic skeleton and the compound having 2 to 4 functional alcoholic hydroxyl groups in dicarboxylic acid synthesis is, for example, preferably 30 to 120 ° C, and more preferably 35 to 100 ° C. When the reaction temperature is lower than 30 ° C, the reaction rate may be decreased. On the other hand, when the reaction temperature is higher than 120 ° C, the reaction rapidly occurs, causing problems such as bumping, increase of by-products, and coloring. There is a case.

  As the dicarboxylic acid contained in the epoxy resin composition of the present invention, among others, hexahydrophthalic anhydride and / or methylhexahydrophthalic anhydride is reacted with a divalent to tetravalent alcohol containing a cyclic aliphatic skeleton. The dicarboxylic acid obtained by the reaction is preferably hexahydrophthalic anhydride and / or methylhexahydrophthalic anhydride and 1,4-cyclohexanedimethanol or hydrogenated bisphenol A. Acids are preferred, and in particular, dicarboxylic acids obtained by reacting hexahydrophthalic anhydride and / or methylhexahydrophthalic anhydride with 1,4-cyclohexanedimethanol are resistant to heat yellowing (heat resistance degradation) and strength. This is preferable.

  The mixing ratio of the dicarboxylic acid in the epoxy resin composition according to the present invention is, for example, 1 to 200 parts by weight, preferably 5 to 100 parts by weight of the alicyclic epoxy resin mixture in the epoxy resin composition. About 150 parts by weight.

  The epoxy resin composition of the present invention, particularly an epoxy resin composition used as a light emitting device sealing material, is for the purpose of preventing oxidative deterioration during heating and obtaining a cured epoxy resin with little coloration. It is preferable to add an antioxidant. Examples of the antioxidant include phenol-based, sulfur-based, and phosphorus-based antioxidants.

  Examples of the phenolic antioxidant include 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-p-ethylphenol, stearyl-β- (3 , 5-di-tert-butyl-4-hydroxyphenyl) propionate and the like; 2,2′-methylenebis (4-methyl-6-tert-butylphenol), 2,2′-methylenebis (4-ethyl- 6-t-butylphenol), 4,4′-thiobis (3-methyl-6-tert-butylphenol), 4,4′-butylidenebis (3-methyl-6-tert-butylphenol), 3,9-bis [1 , 1-Dimethyl-2- {β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} ethyl] 2,4,8,10-tetraoxas Bisphenols such as pyro [5.5] undecane; 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- High molecular type phenols such as 4′-hydroxybenzyl) -s-triazine-2,4,6- (1H, 3H, 5H) trione, tocophenol and the like can be mentioned.

  Examples of the sulfur-based antioxidant include dilauryl-3,3′-thiodipropionate, dimyristyl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, and the like. .

  Examples of phosphorus antioxidants include triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, tris (nonylphenyl) phosphite, diisodecylpentaerythritol phosphite, tris (2,4-di-t- Butylphenyl) phosphite, cyclic neopentanetetraylbis (octadecyl) phosphite, cyclic neopentanetetraylbis (2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetraylbis (2 , 4-di-tert-butyl-4-methylphenyl) phosphite, bis [2-tert-butyl-6-methyl-4- {2- (octadecyloxycarbonyl) ethyl} phenyl] hydrogen phosphite, etc. Fights; 9,10-di Dro-9-oxa-10-phosphaphenanthrene-10-oxide, 10- (3,5-di-t-butyl-4-hydroxybenzyl) -9,10-dihydro-9-oxa-10-phosphaphenanthrene Examples include oxaphosphaphenanthrene oxides such as -10-oxide.

  These antioxidants can be used alone or in combination of two or more. Among them, phenolic antioxidants and sulfur antioxidants, or phenolic antioxidants and phosphorus antioxidants. Like an agent, it is preferable to use 2 or more types in combination.

  As usage-amount of antioxidant, 0.008-1 weight part with respect to 100 weight part of alicyclic epoxy resins in the epoxy resin composition based on this invention, Preferably it is 0.01-0.5. About parts by weight. When the amount of the antioxidant used is less than 0.008 parts by weight based on 100 parts by weight of the alicyclic epoxy resin mixture, oxidation deterioration may not be prevented, and 1 per 100 parts by weight of the alicyclic epoxy resin mixture. If it exceeds the parts by weight, the cured product may turn yellow and precipitate.

  Moreover, it is preferable to add an ultraviolet absorber to the epoxy resin composition of the present invention for the purpose of preventing deterioration of the cured epoxy resin due to ultraviolet irradiation. Examples of the ultraviolet absorber include benzophenone ultraviolet absorbers, benzotriazole ultraviolet absorbers, and benzoate ultraviolet absorbers. Among them, benzophenone ultraviolet absorbers and benzotriazole ultraviolet absorbers are preferable. The amount of the ultraviolet absorber used is, for example, 3 parts by weight or less, for example, about 0.01 to 3 parts by weight with respect to 100 parts by weight of the alicyclic epoxy resin mixture in the epoxy resin composition of the present invention. When the amount of the ultraviolet absorber used is less than 0.01 parts by weight with respect to 100 parts by weight of the alicyclic epoxy resin mixture, deterioration due to ultraviolet light may not be prevented, and with respect to 100 parts by weight of the alicyclic epoxy resin mixture. If it exceeds 3 parts by weight, the cured product may be colored.

  Furthermore, the epoxy resin composition of the present invention may contain a curing catalyst. Examples of the curing catalyst include a cationic polymerization initiator. As the cationic polymerization initiator, a photocationic polymerization initiator that generates a cationic species or Bronsted acid by light irradiation, or a thermal cationic polymerization initiator that generates a cationic species or Bronsted acid by heat can be used. Cationic polymerization initiators can be used alone or in combination of two or more. As the photocationic polymerization initiator, for example, compounds such as sulfonium salt, iodonium salt, diazonium salt, and allene-ion complex can be used. For example, sulfonium salt-based “UVACURE1590” (manufactured by Daicel Cytec Co., Ltd.), “DAICAT11” (manufactured by Daicel Chemical Industries, Ltd.), “CD-1011” (manufactured by Sartomer), “SI-60L”, “ "SI-80L", "SI-100L" (manufactured by Sanshin Chemical Industry Co., Ltd.) and the like; iodonium salt-based "DAICAT12" (manufactured by Daicel Chemical Industries, Ltd.), "CD-1012" (manufactured by Sartomer) ); Diazonium salt type “SP-150”, “SP-170” (manufactured by Asahi Denka Kogyo Co., Ltd.) and the like.

  Examples of the thermal cationic polymerization initiator include, for example, aryldiazonium salts (for example, “PP-33” manufactured by Asahi Denka Kogyo Co., Ltd.), aryliodonium salts, arylsulfonium salts (for example, “FC-509” manufactured by 3M). "UVE1014" manufactured by GE Corporation, "CP-66", "CP-77" manufactured by Asahi Denka Kogyo Co., Ltd., "SI-60L", "SI-80L" manufactured by Sanshin Chemical Industry Co., Ltd., "SI-100L", "SI-110L"), allene-ion complexes (for example, "CG-24-61" manufactured by Ciba Geigy Corporation) and the like. In addition, a system of a chelate compound of a metal such as aluminum or titanium and an acetoacetate ester or a diketone and a silanol or a phenol may be used. Examples of the chelate compound include aluminum trisacetylacetonate and aluminum trisacetoacetate ethyl. Examples of silanols or phenols include triphenylsilanol and bisphenol S.

  As a usage-amount of a curing catalyst, it is 0.1-8 weight part with respect to 100 weight part of alicyclic epoxy resin mixtures in the epoxy resin composition based on this invention, Preferably it is about 0.3-5 weight part. It is. If the amount of the curing catalyst used is less than 0.1 parts by weight with respect to 100 parts by weight of the alicyclic epoxy resin mixture, the curability tends to be insufficient, whereas, with respect to 100 parts by weight of the alicyclic epoxy resin mixture. If it exceeds 8 parts by weight, the cured product may be colored or foamed.

  Furthermore, various additives can be blended in the epoxy resin composition of the present invention as long as the viscosity and transparency are not adversely affected. Examples of such additives include 2- to 6-functional heterocyclic epoxy resins such as triglycidyl isocyanurate (excluding alicyclic epoxy resin A or alicyclic epoxy resin B); aluminum oxide, magnesium oxide, and the like. Metal oxides; silicon compounds such as fine powdered silica, fused silica, crystalline silica; transparent fillers such as glass beads; metal hydroxides such as aluminum hydroxide; powders such as kaolin, mica, quartz powder, graphite, molybdenum disulfide Reinforcing agents or fillers; Colorants or pigments such as titanium dioxide, molybdenum red, bitumen, ultramarine, cadmium yellow, cadmium red, organic dyes; flame retardants such as antimony trioxide, bromine compounds, phosphorus compounds; ion adsorbents Coupling agents; various additives commonly used in epoxy resin compositions such as mold release agents. That.

  The said additive can be added in the range which does not impair the transparency of the epoxy resin composition of this invention, 2-6 functional heterocyclic epoxy resin (alicyclic epoxy resin A or alicyclic epoxy resin B is added. Excluding), metal oxide, silicon compound, transparent filler, metal hydroxide, powdery reinforcing agent, and the amount of filler added is, for example, 100 weight of the alicyclic epoxy resin mixture in the epoxy resin composition of the present invention. 100 parts by weight or less, preferably about 10 to 100 parts by weight per part, and the addition amount of colorant, pigment, flame retardant, ion adsorbent, coupling agent, mold release agent, etc. The amount of the alicyclic epoxy resin mixture in the epoxy resin composition of the present invention is 30 parts by weight or less, for example, about 0.01 to 30 parts by weight.

  Furthermore, the epoxy resin composition of the present invention can be blended with various curable monomers, oligomers, and synthetic resins other than epoxy resins for the purpose of improving the properties of the cured epoxy resin. Diols such as polyester diol and polycarbonate diol, triols, tetraols, vinyl ethers, oxetane compounds, fluororesins, acrylic resins, silicone resins, etc. can be used alone or in combination of two or more. . As a compounding quantity, it can mix | blend in the range which does not impair the original property of the epoxy resin composition of this invention, For example, with respect to 100 weight part of alicyclic epoxy resin mixtures in the epoxy resin composition of this invention 50 parts by weight or less is preferable.

  The epoxy resin composition of the present invention can be produced by a known and commonly used method. For example, a predetermined amount of alicyclic epoxy resin A and alicyclic epoxy resin B, acid anhydride, dicarboxylic acid, if necessary. An additive such as an antioxidant and / or an ultraviolet absorber may be appropriately blended, and the mixture may be stirred and mixed using a stirrer while excluding bubbles under vacuum heating. The temperature at the time of stirring and mixing varies depending on the type of additive and the like, but is usually preferably about 10 to 60 ° C. If the temperature at the time of stirring and mixing is less than 10 ° C, the viscosity is too high and uniform stirring and mixing operations may be difficult. On the other hand, if the temperature at the time of stirring and mixing exceeds 60 ° C, stirring, A curing reaction occurs during mixing, and a normal epoxy resin composition may not be obtained. As the stirrer, general-purpose equipment such as a single-screw or multi-screw extruder, a kneader, and a dissolver equipped with a decompression device can be used. Moreover, as stirring time with the said stirrer, it is about 5 to 60 minutes, for example.

  Since the epoxy resin composition according to the present invention has adhesiveness and exhibits a liquid shape, the cured epoxy resin obtained by curing the epoxy resin composition has high transparency and is bent. Excellent strength, heat resistance, light resistance, heat deterioration resistance, and thermal shock resistance, coating materials, adhesives, photocurable materials, and light receiving elements such as LEDs (light emitting diodes) and CCDs (charge coupled devices) It is useful in various fields including applications such as electrical and electronic sealing materials related to optical semiconductors.

[Hardened epoxy resin]
The cured epoxy resin according to the present invention is obtained by curing the epoxy resin composition. Examples of the method of curing the epoxy resin composition include a method of curing by heating and / or light irradiation.

  Since the epoxy resin composition according to the present invention contains an acid anhydride as a curing agent, the acid anhydride and the epoxy group react by heating to cure the epoxy resin composition. As heating temperature, it is 30-240 degreeC, for example, Preferably it is about 50-200 degreeC. Further, curing may be performed in two or more stages. For example, after primary curing at a temperature of 30 to 130 ° C. (preferably 50 to 130 ° C.) and then secondary curing at a temperature of 135 to 240 ° C. (preferably 135 to 200 ° C.), transparency and heat resistance are achieved. A cured product having good physical properties such as the above can be obtained. Furthermore, when a thermal cationic polymerization initiator is contained as the cationic polymerization initiator, heating causes the acid anhydride to start polymerization and cationic polymerization to start and cure the epoxy resin composition. As heating temperature, it is 30-240 degreeC, for example, Preferably it is 35-200 degreeC. Curing may be carried out in two or more stages, for example, after primary curing at a temperature of 30 to 100 ° C. (preferably 30 to 80 ° C.), secondary at a temperature of 110 to 240 ° C. (preferably 120 to 200 ° C.). By curing, a cured product having good physical properties such as transparency and heat resistance can be obtained.

  Furthermore, when a cationic photopolymerization initiator is contained as the cationic polymerization initiator, the acid anhydride starts to polymerize by irradiating light simultaneously with heating, or before or after heating. Polymerization starts and the epoxy resin composition is cured. As irradiation light, active energy rays such as ultraviolet rays and electron beams can be used. As a light source for performing ultraviolet irradiation, an irradiation source having a lamp output of about 80 to 300 W / cm is usually used, and examples thereof include a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a xenon lamp, a metal halide lamp, and an LED. It is done. The irradiation time varies depending on the type of the light source, the distance between the light source and the coating surface, and other conditions, but it is several tens of seconds at the longest, usually about several seconds. After irradiation with active energy rays, heating can be performed as necessary to complete the curing. In the case of electron beam irradiation, it is preferable to use an electron beam having an energy in the range of 50 to 1000 KeV and set the irradiation amount to 2 to 5 Mrad.

  The heating time required for curing the epoxy resin composition is not particularly limited and can be appropriately adjusted depending on the components constituting the epoxy resin composition, the amount of the epoxy resin composition, and the like. Examples include a method in which primary curing is performed for about 1 to 5 hours and then secondary curing is performed for about 1 to 5 hours.

  The curing reaction may be performed under normal pressure, or may be performed under reduced pressure or under pressure. The atmosphere of the curing reaction is not particularly limited as long as it does not inhibit the curing, and may be any of an air atmosphere, a nitrogen atmosphere, an argon atmosphere, and the like.

  Since the epoxy resin composition according to the present invention contains dicarboxylic acid as a curing agent, when curing the epoxy resin composition, the curing reaction can be allowed to proceed slowly, and by curing the epoxy resin composition The transparency, strength, heat resistance, heat deterioration resistance, light resistance, and thermal shock resistance of the cured epoxy resin can be improved.

  The cured epoxy resin according to the present invention obtained by curing the epoxy resin composition by the above method has high transparency. Light transmittance can be used as an index of transparency. As the light transmittance of the cured epoxy resin according to the present invention, for example, the light transmittance at a wavelength of 400 nm of the cured epoxy resin (thickness 3 mm) is about 80 to 95%, more preferably about 80 to 90%.

  Furthermore, the cured epoxy resin according to the present invention is excellent in heat resistance. As the heat resistance index, for example, glass transition temperature, average linear expansion coefficient, and the like can be used. The glass transition temperature of the cured epoxy resin measured using a thermomechanical analyzer is about 130 to 185 ° C, more preferably about 135 to 155 ° C. Moreover, the average linear expansion coefficient of the epoxy resin hardened | cured material (thickness 10mm) to 50 to 100 degreeC is 50-80 ppm, More preferably, it is about 50-70 ppm. Moreover, the said epoxy resin hardened | cured material is excellent in bending strength, For example, the bending elastic modulus of an epoxy resin hardened | cured material (thickness 4mm) is 2075-2750MPa, More preferably, it is about 2350-2750MPa.

  Furthermore, the epoxy resin cured product according to the present invention is excellent in heat deterioration resistance, light resistance, and heat shock resistance. In the present invention, the heat deterioration resistance is based on the light transmittance after the cured epoxy resin is exposed to a high temperature for a long time. For example, the cured epoxy resin (thickness 3 mm) is heated at 120 ° C. for 500 hours. When applied, the light transmittance at a wavelength of 400 nm is about 74 to 93%, more preferably about 74 to 85%.

In the present invention, the light resistance is based on the light transmittance after light irradiation of a cured epoxy resin for a long time. For example, the cured epoxy resin (thickness 3 mm) has an irradiation intensity of 18 mW / cm ² (using a metal halide lamp). Thus, the light transmittance at a wavelength of 400 nm when irradiated with light at 23 ° C. for 300 hours is about 75 to 90%, more preferably about 80 to 90%.

  In the present invention, the thermal shock resistance is based on the length of a crack (crack) generated when a thermal cycle (repeating heating and cooling) is applied to the cured epoxy resin, for example, cured epoxy resin containing a lead frame. By using a thermal shock tester for (thickness 3 mm), a cooling cycle of −45 ° C. to 100 ° C. is performed 500 times, and the length of cracks generated in the cured epoxy resin is measured.

  The cured epoxy resin of the present invention has high transparency and can maintain high transparency even when exposed to high temperature for a long time or irradiated with light for a long time. Furthermore, the occurrence of cracks (cracks) can be greatly suppressed even when a cooling cycle is applied. That is, the epoxy resin cured product according to the present invention has characteristics that are excellent in heat resistance, heat deterioration resistance, light resistance, and thermal shock resistance. Therefore, there are various applications including coating materials, adhesives, photo-curing materials, and optical / electronic sealing materials related to optical semiconductors such as light receiving elements such as LEDs (light emitting diodes) and CCDs (charge coupled devices). It is useful in various directions.

[Optical semiconductor device]
An optical semiconductor device excites light into an optical semiconductor element by an electric signal supplied from an external electric circuit, transmits this light in the order of a translucent member, an aspheric lens, and an optical fiber, and externally passes through the optical fiber. By transmitting, the optical signal transmitted from the device used for high-speed optical communication or the like by the optical fiber is transmitted through the aspherical lens and the translucent member, and is received by the optical semiconductor element to receive the light. It is a device used for high-speed optical communication or the like by converting a signal into an electrical signal. The optical semiconductor element is sealed by injecting an epoxy resin composition into a predetermined mold and heat-curing (or photocuring) under predetermined conditions. Thereby, the optical semiconductor device in which the optical semiconductor element is sealed with the epoxy resin composition of the present invention is obtained. Since the optical semiconductor device according to the present invention uses the epoxy resin composition according to the present invention as a sealant and protects the periphery of the light emitter, there is no problem of luminance reduction or discoloration due to yellowing, and There are few occurrences of cracks. Therefore, it is useful as a highly reliable optical semiconductor device.

[adhesive]
The adhesive which concerns on this invention is an adhesive which has the epoxy resin composition which concerns on this invention as a main component, and an additive can be suitably added unless the characteristic of this epoxy resin composition is impaired. The adhesive according to the present invention can be suitably used, for example, as an adhesive that bonds a light emitting element, a light receiving element, or the like of an LED. The adhesive according to the present invention is colorless and transparent, and is excellent in strength, heat resistance, light resistance, heat deterioration resistance, and thermal shock resistance, and therefore adheres firmly to the adherend even in a high heat environment or light irradiation environment. The adhesive part does not turn yellow after long-term use.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, the following Examples 1-4, 6, 8, and 9 are described as a reference example. The viscosity (Pa · s) was measured using an E-type viscometer.

（式中、ジカルボン酸が有するメチル基はシクロヘキサン環の３位、又は、４位に結合する） Synthesis example 1

(In the formula, the methyl group of the dicarboxylic acid is bonded to the 3-position or 4-position of the cyclohexane ring)

  In a flask equipped with a stirrer, 100 parts by weight of 4-methyl-hexahydrophthalic anhydride and hexahydrophthalic anhydride mixture (trade name “Licacid MH-700”, manufactured by Shin Nippon Rika Co., Ltd.), 35 parts by weight of 1,6-hexanediol, toluene After 100 parts by weight were charged and mixed under a nitrogen stream at room temperature, the temperature was raised to 80 ° C. and reacted for 6 hours with stirring. Thereafter, toluene was distilled off under reduced pressure using an evaporator to obtain 134 parts by weight of a dicarboxylic acid-containing composition.

（式中、ジカルボン酸が有するメチル基はシクロヘキサン環の３位、又は、４位に結合する） Synthesis example 2

(In the formula, the methyl group of the dicarboxylic acid is bonded to the 3-position or 4-position of the cyclohexane ring)

  A flask equipped with a stirrer was charged with 100 parts by weight of 4-methyl-hexahydrophthalic anhydride (trade name “HN-5500E”, manufactured by Hitachi Chemical Co., Ltd.), 31 parts by weight of neopentyl glycol, and 150 parts by weight of toluene. After mixing below, the temperature was raised to 80 ° C. and reacted for 7 hours with stirring. Thereafter, toluene was distilled off under reduced pressure using an evaporator to obtain 131 parts by weight of a dicarboxylic acid-containing composition.

（式中、ジカルボン酸が有するメチル基はシクロヘキサン環の３位、又は、４位に結合する） Synthesis example 3

(In the formula, the methyl group of the dicarboxylic acid is bonded to the 3-position or 4-position of the cyclohexane ring)

  A flask equipped with a stirrer was charged with 100 parts by weight of 4-methyl-hexahydrophthalic anhydride (trade name “HN-5500E”, manufactured by Hitachi Chemical Co., Ltd.), 44 parts by weight of triethylene glycol, and 150 parts by weight of toluene. After mixing below, the temperature was raised to 80 ° C., and the mixture was reacted for 6 hours with stirring. Thereafter, toluene was distilled off under reduced pressure using an evaporator to obtain 143 parts by weight of a dicarboxylic acid-containing composition.

（式中、ジカルボン酸が有するメチル基はシクロヘキサン環の３位、又は、４位に結合する） Synthesis example 4

(In the formula, the methyl group of the dicarboxylic acid is bonded to the 3-position or 4-position of the cyclohexane ring)

  A flask equipped with a stirrer was charged with 100 parts by weight of 4-methyl-hexahydrophthalic anhydride and hexahydrophthalic anhydride mixture (trade name “Ricacid MH-700”, manufactured by Shin Nippon Chemical Co., Ltd.), 10 parts by weight of cyclohexanedimethanol, After mixing under a nitrogen stream, the temperature was raised to 50 ° C., and the mixture was reacted for 5 hours with stirring to obtain 109 parts by weight of a dicarboxylic acid-containing composition.

（式中、ジカルボン酸が有するメチル基はシクロヘキサン環の３位、又は、４位に結合する） Synthesis example 5

(In the formula, the methyl group of the dicarboxylic acid is bonded to the 3-position or 4-position of the cyclohexane ring)

  A flask equipped with a stirrer was charged with 100 parts by weight of a mixture of 4-methyl-hexahydrophthalic anhydride and hexahydrophthalic anhydride (trade name “Licacid MH-700”, manufactured by Shin Nippon Rika Co., Ltd.) and 12 parts by weight of hydrogenated bisphenol A at room temperature. After mixing under a nitrogen stream, the temperature was raised to 80 ° C. and reacted for 7 hours with stirring to obtain 131 parts by weight of a dicarboxylic acid-containing composition.

Example 1
In a flask equipped with a stirrer, alicyclic epoxy resin A (3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate: trade name “CEL-2021P”, manufactured by Daicel Chemical Industries, Ltd., viscosity at 25 ° C. 237 mPa S) 55 parts by weight, alicyclic epoxy resin B (trade name “YL-7170”, manufactured by Japan Epoxy Resin Co., Ltd.) 40 parts by weight, and alicyclic epoxy resin B (trade name “EHPE 3150”, Daicel Chemical) 5 parts by weight of Kogyo Kogyo Co., Ltd. was charged and mixed under a nitrogen stream at 90 ° C. to obtain an alicyclic epoxy resin mixture (viscosity at 45 ° C., 18700 mPa · s).

To 100 parts by weight of the resulting alicyclic epoxy resin mixture, 68 parts by weight of methylhexahydrophthalic anhydride (trade name “Ricacid MH-700”, manufactured by Shin Nippon Rika Co., Ltd., viscosity 53 mPa · s at 25 ° C.) as a curing agent 8 parts by weight of the dicarboxylic acid obtained in Synthesis Example 1, 0.6 parts by weight of DBU octylate (trade name “SA-102”, manufactured by San Apro) as a curing accelerator, and 2,6-t as an antioxidant -0.1 part by weight of butyl-p-cresol was added and mixed with a stirrer (trade name “Ryotaro Awatori”, manufactured by Shinky Corporation) to obtain an epoxy resin composition 1. In the following paragraphs and Tables 1 and 2, “dicarboxylic acid” means “dicarboxylic acid-containing composition” (specifically, the dicarboxylic acid-containing composition obtained in Synthesis Examples 1 to 5). Shall mean.

Example 2
In a flask equipped with a stirrer, alicyclic epoxy resin A (3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate: trade name “CEL-2021P”, manufactured by Daicel Chemical Industries, Ltd., viscosity at 25 ° C. 237 mPa S) 55 parts by weight, alicyclic epoxy resin B (trade name “YL-7170”, manufactured by Japan Epoxy Resin) 25 parts by weight, and alicyclic epoxy resin B (trade name “EHPE 3150”, Daicel Chemical) 20 parts by weight (produced by Kogyo Co., Ltd.) were charged and mixed under a nitrogen stream at 90 ° C. to obtain an alicyclic epoxy resin mixture (viscosity 15600 mPa · s at 45 ° C.).

  To 100 parts by weight of the resulting alicyclic epoxy resin mixture, 86 parts by weight of methylhexahydrophthalic anhydride (trade name “Licacid MH-700”, manufactured by Shin Nippon Rika Co., Ltd., viscosity 53 mPa · s at 25 ° C.) as a curing agent 10 parts by weight of the dicarboxylic acid obtained in Synthesis Example 1, 0.7 part by weight of DBU octylate (trade name “SA-102”, manufactured by San Apro) as a curing accelerator, and 2,6-t as an antioxidant -0.1 part by weight of butyl-p-cresol was added and mixed with a stirrer (trade name “Ryotaro Awatori”, manufactured by Shinky Corporation) to obtain an epoxy resin composition 2.

Example 3
In a flask equipped with a stirrer, alicyclic epoxy resin A (3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate: trade name “CEL-2021P”, manufactured by Daicel Chemical Industries, Ltd., viscosity at 25 ° C. 237 mPa S) 55 parts by weight, cycloaliphatic epoxy resin B (trade name “YL-7170”, manufactured by Japan Epoxy Resin Co., Ltd.) 45 parts by weight, mixed at 90 ° C. in a nitrogen stream, and alicyclic epoxy resin mixture (Viscosity of 17360 mPa · s at 45 ° C.) was obtained.

  To 100 parts by weight of the obtained alicyclic epoxy resin mixture, 81 parts by weight of the dicarboxylic acid obtained in Synthesis Example 3 and DBU octylate (trade name “SA-102”, manufactured by San Apro) as a curing accelerator were added. 5 parts by weight and 0.1 part by weight of 2,6-tert-butyl-p-cresol as an antioxidant are added and mixed with a stirrer (trade name “Ryotaro Awatori”, manufactured by Shinky Corporation), and epoxy resin Composition 3 was obtained.

Example 4
In a flask equipped with a stirrer, alicyclic epoxy resin A (3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate: trade name “CEL-2021P”, manufactured by Daicel Chemical Industries, Ltd., viscosity at 25 ° C. 237 mPa S) 60 parts by weight, alicyclic epoxy resin B (trade name “YL-7170”, manufactured by Japan Epoxy Resin Co., Ltd.) 40 parts by weight, mixed at 90 ° C. in a nitrogen stream, and alicyclic epoxy resin mixture (Viscosity of 16040 mPa · s at 45 ° C.) was obtained.

  To 100 parts by weight of the resulting alicyclic epoxy resin mixture, 70 parts by weight of 3or4-methyl-hexahydrophthalic anhydride (trade name “HN5500E”, manufactured by Hitachi Chemical Co., Ltd., viscosity 58 mPa · s at 25 ° C.), 8 parts by weight of the dicarboxylic acid obtained in Synthesis Example 4, 0.1 parts by weight of tetra-n-butylsulfonium (trade name “PX4ET”, manufactured by Nippon Chemical Industry Co., Ltd.) as the phosphorus-based curing accelerator, 2, 0.1 part by weight of 6-t-butyl-p-cresol was added and mixed with a stirrer (trade name “Ryotaro Awatori”, manufactured by Shinky Corporation) to obtain an epoxy resin composition 4.

Example 5
In a flask equipped with a stirrer, alicyclic epoxy resin A (3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate: trade name “CEL-2021P”, manufactured by Daicel Chemical Industries, Ltd., viscosity at 25 ° C. 237 mPa S) 60 parts by weight, alicyclic epoxy resin B (trade name “YL-7170”, manufactured by Japan Epoxy Resin Co., Ltd.) 25 parts by weight, and alicyclic epoxy resin B (trade name “EHPE 3150”, Daicel Chemical) 15 parts by weight (produced by Kogyo Co., Ltd.) were charged and mixed under a nitrogen stream at 90 ° C. to obtain an alicyclic epoxy resin mixture (viscosity at 14430 mPa · s at 45 ° C.).

  To 100 parts by weight of the resulting alicyclic epoxy resin mixture, 96 parts by weight of the dicarboxylic acid obtained in Synthesis Example 4 and tetra-n-butylsulfonium (trade name “PX4ET”, Nippon Chemical Industry Co., Ltd.) as a phosphorus curing accelerator 0.25 parts by weight, 2,6-t-butyl-p-cresol 0.1 part by weight as an antioxidant is added and mixed with a stirrer (trade name “Rubbing Awatake”, manufactured by Shinky) As a result, an epoxy resin composition 5 was obtained.

Example 6
In a flask equipped with a stirrer, alicyclic epoxy resin A (3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate: trade name “CEL-2021P”, manufactured by Daicel Chemical Industries, Ltd., viscosity at 25 ° C. 237 mPa S) 60 parts by weight, alicyclic epoxy resin B (trade name “ST4000”, manufactured by Tohto Kasei Co., Ltd.) 10 parts by weight, and alicyclic epoxy resin B (trade name “EHPE 3150”, manufactured by Daicel Chemical Industries, Ltd.) 30 parts by weight were charged and mixed under a nitrogen stream at 90 ° C. to obtain an alicyclic epoxy resin mixture (viscosity at 12270 mPa · s at 45 ° C.).

  100 parts by weight of the resulting alicyclic epoxy resin mixture and 100 parts by weight of methylhexahydrophthalic anhydride as a curing agent (trade name “Licacid MH-700”, manufactured by Shin Nippon Rika Co., Ltd., viscosity 53 mPa · s at 25 ° C.) 16 parts by weight of the dicarboxylic acid obtained in Synthesis Example 3, 0.3 parts by weight of tetra-n-butylsulfonium (trade name “PX4ET”, manufactured by Nippon Kagaku Kogyo Co., Ltd.) as the phosphorus-based curing accelerator, 2 as the antioxidant , 6-t-butyl-p-cresol 0.1 part by weight was added and mixed with a stirrer (trade name “Ryotaro Awatori”, manufactured by Shinky Corporation) to obtain an epoxy resin composition 6.

Example 7
In a flask equipped with a stirrer, alicyclic epoxy resin A (3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate: trade name “CEL-2021P”, manufactured by Daicel Chemical Industries, Ltd., viscosity at 25 ° C. 237 mPa・ S) 65 parts by weight, 35 parts by weight of alicyclic epoxy resin B (trade name “YL-7170”, manufactured by Japan Epoxy Resin Co., Ltd.) are charged and mixed under a nitrogen stream at 90 ° C., and the alicyclic epoxy resin mixture (Viscosity of 14300 mPa · s at 45 ° C.) was obtained.

  To 100 parts by weight of the resulting alicyclic epoxy resin mixture, 81 parts by weight of the dicarboxylic acid obtained in Synthesis Example 5 and DBU octylate as a curing accelerator (trade name “SA-102”, manufactured by San Apro) 0. 6 parts by weight and 0.1 part by weight of 2,6-t-butyl-p-cresol as an antioxidant are added and mixed with a stirrer (trade name “Ryotaro Awatori”, manufactured by Shinky Corporation), and epoxy resin Composition 7 was obtained.

Example 8
In a flask equipped with a stirrer, alicyclic epoxy resin A (3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate: trade name “CEL-2021P”, manufactured by Daicel Chemical Industries, Ltd., viscosity at 25 ° C. 237 mPa S) 75 parts by weight, alicyclic epoxy resin B (trade name “YL-7170”, manufactured by Japan Epoxy Resin Co., Ltd.) 20 parts by weight, and alicyclic epoxy resin B (trade name “EHPE 3150”, Daicel Chemical) 5 parts by weight (produced by Kogyo Co., Ltd.) were charged and mixed under a nitrogen stream at 90 ° C. to obtain an alicyclic epoxy resin mixture (viscosity at 12500 mPa · s at 45 ° C.).

  To 100 parts by weight of the resulting alicyclic epoxy resin mixture, 98 parts by weight of methylhexahydrophthalic anhydride (trade name “Ricacid MH-700”, manufactured by Shin Nippon Rika Co., Ltd., viscosity 53 mPa · s at 25 ° C.) as a curing agent 15 parts by weight of the dicarboxylic acid obtained in Synthesis Example 1, 0.5 parts by weight of DBU octylate (trade name “SA-102”, manufactured by San Apro) as a curing accelerator, and 2,6-t as an antioxidant -0.1 part by weight of butyl-p-cresol was added and mixed with a stirrer (trade name “Ryotaro Awatori”, manufactured by Shinky Corporation) to obtain an epoxy resin composition 8.

Example 9
In a flask equipped with a stirrer, alicyclic epoxy resin A (3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate: trade name “CEL-2021P”, manufactured by Daicel Chemical Industries, Ltd., viscosity at 25 ° C. 237 mPa S) 75 parts by weight, alicyclic epoxy resin B (trade name “ST4000”, manufactured by Toto Kasei Co., Ltd.) 20 parts by weight, and alicyclic epoxy resin B (trade name “EHPE 3150”, manufactured by Daicel Chemical Industries, Ltd.) ) 5 parts by weight were charged and mixed under a nitrogen stream at 90 ° C. to obtain an alicyclic epoxy resin mixture (viscosity at 1,010 mPa · s at 45 ° C.).

  To 100 parts by weight of the resulting alicyclic epoxy resin mixture, 105 parts by weight of methylhexahydrophthalic anhydride (trade name “Ricacid MH-700”, manufactured by Shin Nippon Rika Co., Ltd., viscosity 53 mPa · s at 25 ° C.) as a curing agent 8 parts by weight of the dicarboxylic acid obtained in Synthesis Example 3, 0.5 part by weight of DBU octylate (trade name “SA-102”, manufactured by San Apro) as a curing accelerator, and 2,6-t as an antioxidant -0.1 part by weight of butyl-p-cresol was added and mixed with a stirrer (trade name “Ryotaro Awatori”, manufactured by Shinky Corporation) to obtain an epoxy resin composition 9.

Example 10
In a flask equipped with a stirrer, alicyclic epoxy resin A (3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate: trade name “CEL-2021P”, manufactured by Daicel Chemical Industries, Ltd., viscosity at 25 ° C. 237 mPa S) 75 parts by weight, alicyclic epoxy resin B (trade name “YL-7170”, manufactured by Japan Epoxy Resin Co., Ltd.) 5 parts by weight, and alicyclic epoxy resin B (trade name “EHPE 3150”, Daicel Chemical) 20 parts by weight (produced by Kogyo Co., Ltd.) were charged and mixed under a nitrogen stream at 90 ° C. to obtain an alicyclic epoxy resin mixture (viscosity of 11600 mPa · s at 45 ° C.).

  To 100 parts by weight of the resulting alicyclic epoxy resin mixture, 96 parts by weight of the dicarboxylic acid obtained in Synthesis Example 5, and tetra-n-butylsulfonium (trade name “PX4ET”, Nippon Chemical Industry Co., Ltd.) as a phosphorus curing accelerator 0.25 parts by weight, 2,6-t-butyl-p-cresol 0.1 part by weight as an antioxidant is added and mixed with a stirrer (trade name “Rubbing Awatake”, manufactured by Shinky) As a result, an epoxy resin composition 10 was obtained.

Comparative Example 1
To 100 parts by weight of alicyclic epoxy resin A (bisphenol A type liquid epoxy resin: trade name “Epicoat 828”, Japan Epoxy Resin Co., Ltd., viscosity 9100 mPa · s at 25 ° C.), 3or 4-methyl-hexahydro anhydride phthalate as a curing agent 89 parts by weight of acid (trade name “HN5500E”, manufactured by Hitachi Chemical Co., Ltd., viscosity 62 mPa · s at 25 ° C.), tetra-n-butylsulfonium (trade name “PX4ET”, manufactured by Nippon Chemical Industry Co., Ltd.) as a phosphorus curing accelerator ) 0.1 parts by weight, 0.16 parts by weight of 2,6-t-butyl-p-cresol as an antioxidant is added and mixed with a stirrer (trade name “Ryotaro Awatake”, manufactured by Shinky Corporation). The epoxy resin composition 11 was obtained.

  The obtained epoxy resin composition 11 was cured at 80 ° C. for 4 hours as primary curing, followed by curing at 150 ° C. for 3 hours as secondary curing, to obtain a cured epoxy resin 11.

[Methods for measuring physical properties and methods for evaluating effects]
(1) Heat resistance test (glass transition temperature (Tg) and average linear expansion coefficient (ppm) of cured epoxy resin)
The epoxy resin compositions 1 to 11 obtained in Examples and Comparative Examples were subjected to heat curing at 80 ° C. for 4 hours as primary curing and then at 150 ° C. for 3 hours as secondary curing, and a test piece (length 4 mm). , Width 4 mm, thickness 10 mm), glass transition temperature (Tg) and average coefficient of linear expansion (ppm) were measured and used as heat resistance indicators.
The obtained test pieces 1 to 11 were heated using a TMA (thermomechanical measuring device) at a heating rate of 5 ° C./min, and the glass transition point Tg (° C.) was measured.
For the average linear expansion coefficient, the length L ₀ (mm) of each of the test pieces 1 to 11 was measured, and then the cured epoxy resin was heated using TMA (thermomechanical measuring device) under normal pressure. The length L ₁ (mm) of the test piece at 50 ° C. and the length L ₂ (mm) of the test piece at 100 ° C. when heating at a rate of 5 ° C./min and raising the temperature from 50 ° C. to 100 ° C. Was measured, and the average value of the dimensional change of the test piece was determined by the following formula. In addition, “TMA / SS6100” (manufactured by Seiko Instruments Inc.) was used as a TMA (thermomechanical measuring device).

Average linear expansion coefficient (ppm) = (L ₂ −L ₁ / L ₀ × 50) × 10 ⁶

(2) Light transmittance test (light transmittance (%))
Epoxy resin compositions 1 to 11 obtained in Examples and Comparative Examples were cured at 80 ° C. for 4 hours as primary curing, followed by thermosetting at 150 ° C. for 3 hours as secondary curing, and an epoxy having a thickness of 3 mm. A cured resin was produced and used as a test piece.
The test piece was measured for light transmittance (%) at a wavelength of 400 nm using a trade name “UV-2450” (manufactured by Shimadzu Corporation).

(3) Bending strength test (flexural modulus)
The epoxy resin compositions 1 to 11 obtained in the examples and comparative examples were cured at 80 ° C. for 4 hours as a primary curing, followed by heat curing at 150 ° C. for 3 hours as a secondary curing, and an epoxy having a thickness of 4 mm. A cured resin was produced and used as a test piece.
The above-mentioned test piece was used at a bending speed of 1 mm / min according to JIS K7171, using a trade name “RTC-1350A” (manufactured by Orientec), and the flexural modulus (MPa) was measured.

(4) Heat resistance degradation The test piece obtained by the said light transmittance test was heat-processed at 120 degreeC for 500 hours (thermal deterioration test), and light transmittance (%) in wavelength 400nm was trade name "UV" after that. -2450 "(manufactured by Shimadzu Corporation).

(5) Light resistance The test piece obtained in the above light transmittance test was used with the trade name “Super Winmini” (manufactured by Daipla Wintes), irradiation intensity 18 mW / cm ² (using a metal halide lamp), temperature Ultraviolet rays were irradiated at 23 ° C. for 300 hours, and then light transmittance (%) at a wavelength of 400 nm was measured using “UV-2450” (manufactured by Shimadzu Corporation).

(6) Thermal shock resistance Each of the epoxy resin compositions 1 to 11 obtained in the examples and comparative examples is composed of LED lead frames (trade name “EME2003-ver2”, manufactured by Enomoto) near the center of the cured epoxy resin. As shown in FIG. 1, the sample is cast into a mold, and is cured as a primary curing at 80 ° C. for 4 hours, followed by a secondary curing as 150 ° C. for 3 hours, and the test pieces 1 to 11 containing lead frames ( A thickness of 3 mm) was obtained.
The obtained test piece is exposed to an atmosphere of −45 ° C. and subsequently subjected to a heat cycle of 500 times exposed to an atmosphere of 100 ° C., and the length of a crack (crack) in the test piece generated from the lead frame is measured. And evaluated according to the following criteria. The length of the crack was measured as occurring from the tip of the lead frame.
Evaluation Criteria Based on the length of the cracks generated in the test piece 11, the case where the length of the cracks generated in the test piece did not exceed 50% was designated as “◯” for the test piece with each lead frame.

  The physical properties and evaluation of the cured epoxy resins 1 to 11 obtained in Examples and Comparative Examples are summarized in Tables 1 and 2 below.

  From the said Table 1, 2, the epoxy resin hardened | cured material 1-10 obtained by the Example has favorable bending strength, heat-resistant deterioration property, and light resistance. Moreover, the epoxy resin compositions 1-10 obtained by the Example contain the alicyclic epoxy resin A whose viscosity in 25 degreeC contains 1000 mPa * s or less, and 25 degreeC obtained by nuclear hydrogenating an aromatic epoxy resin. The solid alicyclic epoxy resin B is in the range of A / B (weight ratio) = 35/65 to 95/5, whereby the obtained cured epoxy resin has good thermal shock resistance.

Claims (5)

The following formulas (3a) to (3g)

(In the formula (3g), n represents an integer of 1 to 30.)
Solid fat at 25 ° C. obtained by nuclear hydrogenation of alicyclic epoxy resin A, which is at least one selected from alicyclic epoxy resins represented by the following formula , and bisphenol A type epoxy resin or bisphenol F type epoxy resin A mixture containing cyclic epoxy resin B at a ratio of A / B (weight ratio) = 35/65 to 95/5, and an alicyclic epoxy resin mixture having a viscosity at 45 ° C. of 60000 mPa · s or less An acid anhydride having a viscosity at 25 ° C. of 500 mPa · s or less and a dicarboxylic acid ,
The dicarboxylic acid is represented by the following formula (2)

(In formula, R < ¹ > -R < ⁸ > is the same or different, and shows a hydrogen atom, a methyl group, or an ethyl group. X is a C3-C20 bivalent cyclic hydrocarbon group or carbon number. 2 to 20 divalent linear, branched, or 2 or more of divalent cyclic hydrocarbon groups having 3 to 20 carbon atoms bonded to each other with or without oxygen atoms. A divalent group containing a cyclic aliphatic skeleton of ˜22)
An epoxy resin composition which is a dicarboxylic acid having a cycloaliphatic skeleton represented by the formula: The epoxy resin composition according to claim 1 , comprising an antioxidant and / or an ultraviolet absorber. A cured epoxy resin obtained by curing the epoxy resin composition according to claim 1 . The optical semiconductor device sealed using the epoxy resin composition of Claim 1 or 2 . An adhesive comprising the epoxy resin composition according to claim 1 .