JP6520603B2 - Internal epoxy compound having benzene ring and thermosetting composition - Google Patents

Description

  The present invention relates to an epoxy compound excellent in thermal responsiveness and storage stability to high temperatures.

  Epoxy compounds have properties such as cured products having excellent optical properties, mechanical properties, electrical properties, heat resistance, adhesiveness, moisture resistance, water resistance, chemical resistance, etc. It is widely used as a component material for various applications such as display device applications, machine component materials, electric and electronic component materials, automobile component materials, civil engineering and construction materials, molding materials, paints, adhesives and the like.

  Commonly used epoxy compounds are produced by the reaction of bisphenol and epichlorohydrin, so-called epi-bis epoxy resins, novolac epoxy resins produced by the reaction of novolac phenol and epichlorohydrin, etc. The In general, epoxy compounds are cured by thermal addition reaction using an active hydrogen compound as a curing agent to develop various properties. As a curing agent for the epoxy compound, amines, polymercaptans, acid anhydrides, polycarboxylic acid resins, phenol / novolac resins, etc. are used.

  In general, when amines and polymercaptans are used, curing is fast, and curing is completed in a low temperature and short time. Since the storage stability in one solution can not be ensured, the main agent and the curing agent are usually mixed and used immediately before use. Moreover, in order to ensure the storage stability in one solution, a latent curing agent that generates an active hydrogen compound by light or heat is used.

  On the other hand, when acid anhydrides and polycarboxylic acid resins are used, curing is slow, and high temperature and long time heating are required. Therefore, a curing accelerator is usually used in combination to lower the curing temperature and shorten the curing time. Tertiary amines are the most common as curing accelerators. However, when a tertiary amine is used in combination, there is a problem in heat responsiveness, such as a partial curing reaction proceeds even at low temperature heating when drying the solvent in the compounding solution. In addition, there is a problem that melt viscosity increases when tertiary amine is used in combination. That is, the thermosetting composition containing an epoxy compound and an acid anhydride had room for improvement in terms of storage stability.

WO 2012/046553 pamphlet

  The present invention has been made in view of the above-mentioned present situation, and is excellent in storage stability when compounded with an acid anhydride or a polycarboxylic acid resin, and excellent thermal stability which does not react at low temperature heating but reacts only at high temperature heating. It aims at providing an epoxy compound and a thermosetting composition which show responsiveness.

  As a result of intensive studies to solve the above problems, a thermosetting composition comprising an internal epoxy compound having a benzene ring and having a plurality of epoxy groups in the molecule, and a polycarboxylic acid resin or an acid anhydride curing agent, It was found to exhibit excellent storage stability and thermal responsiveness. The present invention has been completed based on these findings.

That is, the present invention relates to an internal epoxy compound having an epoxy group inside the molecule, which is characterized by being represented by the following general formula (1).
General formula (1)
(Wherein, X represents a monovalent aliphatic hydrocarbon group,
n represents an integer of 3 to 6; )

  The present invention also relates to the above-mentioned internal epoxy compound, wherein X is a monovalent aliphatic hydrocarbon group of 1 to 10 carbon atoms.

  The present invention also relates to a thermosetting composition comprising the above internal epoxy compound and a polycarboxylic acid resin or an acid anhydride curing agent.

  The present invention also relates to a thermosetting composition further comprising an epoxy compound other than the internal epoxy compound.

  The present invention also relates to a thermosetting composition wherein the molar ratio of the epoxy group in the composition to the carbonyl group of the polycarboxylic acid resin or the acid anhydride curing agent is 1: 0.4 to 1: 1.5. About.

  The present invention also relates to a cured product obtained by curing the thermosetting composition.

According to the present invention, an epoxy compound and a thermosetting resin which are excellent in storage stability when compounded with an acid anhydride or a polycarboxylic acid resin, exhibit excellent thermal responsiveness which does not react at low temperature heating but reacts only at high temperature heating It was possible to provide a composition.

FIG. 1 is a ¹ H-NMR spectrum of a compound (1).

  The internal epoxy compound which has an epoxy group in the inside of the molecule | numerator in this invention is demonstrated below.

  The internal epoxy compound which has an epoxy group in the molecule | numerator inside in this invention has a structure represented by the said General formula (1). X represents a monovalent aliphatic hydrocarbon group, and n represents an integer of 3 to 6.

  Examples of monovalent hydrocarbon groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl and octyl. Group, nonyl group, decyl group, lauryl group, tetradecyl group, cetyl group, stearyl group, behenyl group and the like. In view of the reactivity of the internal epoxy, linear aliphatic hydrocarbon groups with low steric hindrance are preferred. In particular, a C1-C10 monovalent aliphatic hydrocarbon group is preferable.

  As a preferable specific example of a compound represented by General formula (1), the following compounds are mentioned, for example.

  The manufacturing method of the internal epoxy compound which has an epoxy group in the inside of the molecule | numerator represented by said General formula (1) in this invention is demonstrated below.

  The internal epoxy compound which has an epoxy group in the inside of the molecule | numerator represented by the said General formula (1) in this invention can be synthesize | combined by various methods. A method of synthesizing by combining a compound having a benzene ring and a compound having an internal epoxy group, after combining a compound having a benzene ring and an unsaturated hydrocarbon compound having a carbon-carbon double bond inside the molecule, the molecule The method of couple | bonding oxygen with the internal carbon-carbon double bond, and introduce | transducing an epoxy group etc. are mentioned. The reaction for coupling the two compounds includes esterification.

  Particularly preferred examples are olefins formed by esterification of an aromatic carboxylic acid having a benzene ring and 3 or more carboxyl groups and an unsaturated aliphatic alcohol having a carbon-carbon double bond at the β position of a hydroxyl group. Methods of epoxidizing the body can be mentioned.

  As an aromatic carboxylic acid having a benzene ring and three or more carboxyl groups, 1,2,3-benzenetricarboxylic acid, 1,2,4-benzenetricarboxylic acid, 1,3,5-benzenetricarboxylic acid, benzene- 1,2,4,5-tetracarboxylic acid, benzene pentacarboxylic acid, benzene hexacarboxylic acid and the like.

  Examples of unsaturated aliphatic alcohols having a carbon-carbon double bond at the β-position of hydroxyl group include crotyl alcohol, cis-2-penten-1-ol, trans-2-penten-1-ol and cis-2-hexene -1-ol, trans-2-hexen-1-ol, cis-2-hepten-1-ol, trans-2-hepten-1-ol, cis-2-octene-1-ol, trans-2-octene -1-ol, cis-2-nonen-1-ol, trans-2-nonen-1-ol, trans-2-decen-1-ol, trans-2-undecen-1-ol, 2-dodecenol, trans -2-tridecene-1-ol, and the like.

  Although there are various esterification methods, esterification is carried out by dehydration condensation of an aromatic ring-containing carboxylic acid and an unsaturated aliphatic alcohol having a carbon-carbon double bond at the β position of the hydroxyl group, or Dehydrohalogenation and decarboxylation of esterified acid anhydride or acid halide of carboxylic acid containing benzene ring with unsaturated aliphatic alcohol having carbon-carbon double bond at β position of hydroxyl group The method is mentioned.

  A solvent and a catalyst can be used in the above-mentioned dehydration condensation reaction as needed. The solvent to be used may be any solvent other than a solvent which reacts with the reaction substrate such as alcohol, amine or carboxylic acid. For example, hexane, heptane, octane, cyclohexane, benzene, toluene, ethylbenzene, xylene, ethyl acetate, butyl acetate, isobutyl acetate, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, dichloromethane, chloroform, dimethyl sulfoxide, dimethyl formamide, dimethyl acetamide etc. Be

  The catalyst used is an acid catalyst such as sulfuric acid, hydrochloric acid, methanesulfonic acid or p-toluenesulfonic acid, a base catalyst such as sodium hydroxide or sodium carbonate, triethylamine, tributylamine, trioctylamine, tetramethylethylenediamine, N, N -Amines such as dimethylethanolamine, N, N-dimethylbenzylamine, pyridine, 4- (dimethylamino) pyridine, imidazole, N-methylimidazole, iron (III), zirconium (IV), scandium (III), titanium (IV), salts and complexes containing metal ions such as tin (IV) and hafnium (IV), and ammonium salts such as diphenyl ammonium triflate and pentafluorophenyl ammonium triflate.

  The above dehydration condensation reaction can be carried out using a condensing agent. The condensing agent can activate a carboxylic acid or alcohol and carry out the esterification reaction under mild conditions, and at the same time the by-product water is combined with the condensing agent to become another compound, so It is a compound having both catalytic action and water removal action. Such condensing agents include, for example, dicyclohexylcarbodiimide, diidopropylcarbodiimide, 1-ethyl-3- (N, N-dimethylaminopropyl) carbodiimide hydrochloride, carbonyl dimidazole, ethyl chloroformate, isobutyl chyloformate, p- Toluenesulfonyl chloride, 2,4,6-trichlorobenzoic acid chloride, 2-methyl-6-nitrobenzoic acid anhydride, o- (7-azabenzotriazol-1-yl) -N, N, N, N-tetra Methyluronium hexafluorophosphate etc. are mentioned.

  Further, in the above dehydrohalogenation reaction and decarboxylation reaction, a solvent and a catalyst can be used as needed. The solvent to be used can use the solvent illustrated in the said dehydration condensation reaction. As the catalyst to be used, there can be used a base and an amine catalyst exemplified in the above dehydration condensation reaction for neutralizing a hydrogen halide coming off and a carboxylic acid.

  The reaction conditions of the above dehydration condensation reaction, dehydrohalogenation reaction, and decarboxylation reaction differ depending on the type and amount of the solvent used and the catalyst. For example, when dehydrating condensation is performed without a catalyst, a high temperature is required, so 70 to 250 ° C. is preferable. It is preferable to make it react in the range of -20-50 degreeC by the dehydration condensation using a condensing agent, dehydrohalogenation, and decarboxylation reaction.

Olefin epoxidation can be carried out using a conventional oxidizing agent.

  Examples of the oxidizing agent include oxygen-containing gas, hydrogen peroxide, inorganic peroxides such as sodium peroxide, peracetic acid, perbenzoic acid, m-chloroperbenzoic acid, p-nitroperbenzoic acid, monoperoxy phthalic acid And organic peroxides such as magnesium acid, peroxymaleic acid, peroxytrifluoroacetic acid, peroxyphthalic acid, peroxylauric acid, tert-butyl hydroperoxide, cumene hydroperoxide, menthyl hydroperoxide, 1-methylhexane hydroperoxide and the like.

  A catalyst can be used as needed in the epoxidation reaction. For example, metal compounds containing tungsten, molybdenum, vanadium, titanium, rhenium, ruthenium, etc., aldehydes such as acetaldehyde, isobutyraldehyde, isovaleraldehyde, trimethylacetaldehyde, etc., α-aminomethylphosphonic acid, α-aminoethylphosphonic acid, etc. And quaternary onium salts such as .alpha.-aminophosphonic acids, trioctylmethylammonium chloride, trioctylethylammonium bromide, dilauryldimethylammonium iodide, stearyldimethylbenzylammonium hydrogen phosphate and the like.

  As the solvent used for the epoxidation reaction, those which do not react with the above oxidizing agent can be used. For example, hexane, heptane, octane, cyclohexane, benzene, toluene, ethylbenzene, xylene, ethyl acetate, butyl acetate, isobutyl acetate, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, dichloromethane, chloroform, dimethyl sulfoxide, dimethyl formamide, dimethyl acetamide etc. Be

  The reaction temperature of the epoxidation reaction varies depending on the oxidizing agent, catalyst and solvent to be used, but is preferably 0 to 150 ° C, more preferably 0 to 50 ° C.

  The thermosetting composition of the present invention will be described.

  As a curing agent used by this invention, polycarboxylic acid resin and an acid anhydride are mentioned.

  The polycarboxylic acid resin is not particularly limited as long as it is a resin having an acid value. For example, an acid value containing acrylic resin, an acid value containing urethane resin, an acid value containing polyester resin, etc. may be mentioned. The more the crosslinking point is, the stronger the cured product is obtained, so that the acid value is preferably 10 mg KOH / g or more. Further, in view of storage stability, those having an acid value lower than 80 mg KOH / g are preferable.

  As the acid anhydrides, anhydrides of compounds having a plurality of carboxyl groups in one molecule are preferable. As these acid anhydrides, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic acid anhydride, ethylene glycol bis trimellitate, glycerol tris trimellitate, maleic anhydride, tetrahydrophthalic anhydride, methyl Tetrahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, methyl endomethylenetetrahydrophthalic anhydride, methylbutenyltetrahydrophthalic anhydride, dodecenyl succinic anhydride, hexahydrophthalic anhydride, methyl hexahydrophthalic anhydride, succinic anhydride, methyl Cyclohexene dicarboxylic acid anhydride, chlorendic acid anhydride and the like can be mentioned. Among these, methyl tetrahydrophthalic anhydride, dodecenyl succinic anhydride, methyl hexahydrophthalic anhydride, and a mixture of methyl hexahydrophthalic anhydride and hexahydrophthalic anhydride which are liquid at normal temperature and pressure are preferable.

  The content of the curing agent is such that the molar ratio of the epoxy group in the composition to the carbonyl group of the polycarboxylic acid resin or acid anhydride curing agent is 1: 0.01 to 1: 2.0, and preferably It is 1: 0.4 to 1: 1.5.

  A curing accelerator may be optionally used in combination with the thermosetting composition of the present invention. As curing accelerators, organophosphorus compounds such as triphenylphosphine and tributylphosphine, quaternary phosphonium salts such as ethyltriphenylphosphonium bromide, diethyl tetrabutylphosphonium dithiophosphate, 1,8-diazabicyclo (5,5 4,0) Undecane-7-ene, salts of 1,8-diazabicyclo (5,4,0) undecane-7-ene with octylic acid, quaternary ammonium salts such as zinc octylate, tetrabutylammonium bromide and the like Be These curing assistants can be contained in a ratio of 0.001 to 0.1 parts by mass with respect to 1 part by mass of the curing agent.

  The thermosetting composition of the present invention may further contain an epoxy compound different from the internal epoxy compound having an epoxy group in the inside of the molecule.

  The above epoxy compound is not particularly limited, and as the epoxy compound, for example, bisphenol A epoxy compound, bisphenol F epoxy compound, bisphenol S epoxy compound, phenol novolac epoxy compound, cresol novolac epoxy compound, fat Cyclic epoxy compounds, hydantoin type epoxy compounds, hydrogenated bisphenol A type epoxy compounds, aliphatic type epoxy compounds, glycidyl ether type epoxy compounds, biphenyl type epoxy compounds, dicyclo cyclic type epoxy compounds, naphthalene type epoxy compounds, etc. may be mentioned. These can be used alone or in combination of two or more.

  A solvent can be added to the thermosetting composition of this invention as needed. For example, alcohols such as methanol and ethanol, ethers such as tetrahydrofuran, glycol ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether, ethylene glycol alkyl ether acetates such as methyl cellosolve acetate and ethyl cellosolve acetate, diethylene glycol monomethyl ether , Diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycols such as diethylene glycol ethyl methyl ether, propylene glycol propyl ether, propylene glycol ethyl ether, propylene glycol propyl ether, propylene glycol butyl ether Which propylene glycol monoalkyl ethers, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate, propylene glycol alkyl ether acetates such as propylene glycol butyl ether acetate, propylene glycol methyl ether propionate, propylene glycol ethyl Propylene glycol alkyl ether propionates such as ether propionate, propylene glycol propyl ether propionate, propylene glycol butyl ether propionate, rhombic hydrocarbons such as toluene and xylene, methyl ethyl ketone, cyclohexanone, 4-hydroxy-4 -Methyl-2-pe Ketones such as tanone and methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, methyl hydroxyacetate, ethyl hydroxyacetate, hydroxy Butyl acetate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, methyl 3-hydroxypropionate, ethyl 3-hydroxypropionate, propyl 3-hydroxypropionate, butyl 3-hydroxypropionate, 2-hydroxy-3-methylbutane Methyl acetate, methyl methoxyacetate, ethyl methoxyacetate, propyl methoxyacetate, butyl methoxyacetate, methyl ethoxyacetate, ethyl ethoxyacetate, propyl ethoxyacetate, butyl ethoxyacetate, methyl propoxyacetate, propoxyacetic acid Ethyl, propyl propoxyacetate, butyl propoxyacetate, methyl butoxyacetate, ethyl butoxyacetate, propyl butoxyacetate, butyl butoxyacetate, methyl 2-methoxypropionate, ethyl 2-methoxypropionate, propyl 2-methoxypropionate, 2-methoxy Butyl propionate, methyl 2-ethoxypropionate, ethyl 2-ethoxypropionate, propyl 2-ethoxypropionate, butyl 2-ethoxypropionate, methyl 2-butoxypropionate, ethyl 2-butoxypropionate, 2-butoxypropion Acid propyl, butyl 2-butoxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, 3-ethyl ethyl ketone Methyl propionate, ethyl 3-ethoxypropionate, propyl 3-ethoxypropionate, butyl 3-ethoxypropionate, methyl 3-propoxypropionate, ethyl 3-propoxypropionate, propyl 3-propoxypropionate, 3-propoxypropion Esters such as butyl acid, methyl 3-butoxypropionate, ethyl 3-butoxypropionate, propyl 3-butoxypropionate, butyl 3-butoxypropionate and the like can be mentioned.

  The thermosetting composition of the present invention may be, if necessary, an inorganic filler such as titanium oxide, alumina or silica, a surface conditioner such as a silane coupling agent, a phenolic antioxidant, a phosphorus antioxidant, a sulfur type It may further contain an additive such as an antioxidant.

  The method for producing the thermosetting composition of the present invention is not particularly limited. For example, an internal epoxy compound having an epoxy group in the molecule, and an acid anhydride curing agent or a polycarboxylic acid resin as an organic solvent are used. It can be obtained by dissolving and adding and mixing other epoxy compounds and additives as needed.

  The resin composition of the present invention is cured by heating. The temperature is usually maintained at 100 ° C. or higher, preferably 150 ° C. or higher, usually 250 ° C. or lower, preferably 200 ° C. or lower, for usually 0.1 to 24 hours.

  As a method of shaping the resin composition of the present invention, a method of molding using a mold, a method of coating on a substrate, and the like can be mentioned. As a method of molding using a mold, after injection of the composition of the present invention into a mold, the composition is cured by the above-mentioned method and demolded to obtain a molded body comprising the composition of the present invention it can. When molding is performed using a mold, a molded body to which the surface shape of the mold is transferred can also be obtained. At this time, precision molding can be performed by using the composition of the present invention which is liquid at the time of molding. The molded product thus obtained has a refractive index of usually 1.5 or more, preferably 1.6 or more, and can be used as an optical component such as a lens, a prism, a waveguide, or a substrate.

  EXAMPLES The present invention will be specifically described below by way of examples, but the present invention is not limited thereto. In addition, unless there is particular notice, "%" means "weight%" and "part" means "weight part."

Example 1

(Esterification process)
In a reaction vessel equipped with a stirrer, a thermometer and a gas inlet tube, 10.5 parts of 1,3,5-tricarboxylic acid, 200 parts of acetone and 26.3 parts of 1-methylimidazole were charged, and stirred under ice-cooling. 30.5 parts of p-toluenesulfonyl chloride was added over 30 minutes. After stirring for 30 minutes, 12.6 parts of crotyl alcohol was added dropwise over 30 minutes. The reaction mixture was removed from the ice bath and allowed to react at room temperature for 2 hours, and ¹ H-NMR confirmed that the reaction was complete. The reaction solution was transferred to a separatory funnel, and ethyl acetate and 10% hydrochloric acid were added to separate the phases. The organic layer was further washed with saturated aqueous sodium hydrogen carbonate solution and saturated brine, dried over magnesium sulfate, and the solvent was removed by an evaporator to obtain 10.9 parts of a reaction intermediate (1-1).

(Epoxidation process)
Into a reaction container equipped with a stirrer and a thermometer, 10.9 parts of the above intermediate (1-1), 65.9 parts of sodium hydrogencarbonate, 130 parts of acetone and 120 parts of water were charged, and the mixture was stirred at room temperature. Here, 88.5 parts of oxone (potassium peroxysulfate) was divided into four portions and added every hour. The reaction was allowed to proceed at room temperature overnight, and ¹ H-NMR confirmed that the reaction was complete. The reaction solution was transferred to a separatory funnel, water was added, and the mixture was extracted with ethyl acetate. After washing with water and drying over magnesium sulfate, the solvent was distilled off with an evaporator to obtain 7.3 parts of compound (1). The structure of the obtained compound (1) was confirmed by ¹ H-NMR. The ¹ H-NMR chart of the compound (1) is shown in FIG.

Example 2

The compound (2) was synthesized in the same manner as in Example 1 except that benzene-1,2,4,5-tetracarboxylic acid was used instead of 1,3,5-tricarboxylic acid in Example 1. The structure of the obtained compound (2) was confirmed by 1 H-NMR.

Example 3

The compound (3) was synthesized in the same manner as in Example 1 except that benzenepentacarboxylic acid was used instead of 1,3,5-tricarboxylic acid in Example 1. The obtained compound (3) confirmed the structure by 1 H-NMR.

Example 4

The compound (4) was synthesized in the same manner as in Example 1 except that benzenehexacarboxylic acid was used instead of 1,3,5-tricarboxylic acid in Example 1. The obtained compound (4) was confirmed in its structure by 1 H-NMR.

Example 5

A compound (5) was synthesized in the same manner as in Example 1 except that trans-2-octen-1-ol was used instead of crotyl alcohol in Example 1. The structure of the obtained compound (5) was confirmed by ¹ H-NMR.

Example 6

The compound (6) was synthesized in the same manner as in Example 1 except that trans-2-tridecene-1-ol was used instead of crotyl alcohol in Example 1. The obtained compound (6) was confirmed in structure by ¹ H-NMR.

  Subsequently, Table 1 shows a blending example of the resin composition. In the table, "mol" indicates the number of moles of functional groups, and the epoxy compound of the general formula (1) and epoxy compounds other than the general formula (1) have an epoxy group content, and the curing agent has an carbonyl group content in the curing agent. It blended so that it might become the quantity shown in Table 1.

The compounds used in Table 1 are shown below.
jER 828 (bisphenol A type epoxy resin) ··· Mitsubishi Chemical Corporation jER 630 (N, N- diglycidyl 4-glycidyloxyaniline) · · · Mitsubishi Chemical Corporation
MHHPA (Methyl Hexahydrophthalic Anhydride) ··· Shin Nippon Rika Co., Ltd., RIKASHID MH 700
THPA (Tetrahydrophthalic Anhydride) ··· Shin Nippon Rika Co., Ltd., RIKASHID TH
SG-700AS (acid value-containing acrylic resin) ... manufactured by Nagase ChemteX (acid value: 34 mg KOH / g)
BDMA (N, N-benzyldimethylamine) ... Wako Pure Chemical Industries, Ltd.

Examples 7-16, Comparative Examples 1-3
2-butanone was added to the resin composition of the formulation example shown in Table 1 to prepare a solution having a solid content of 80% to obtain a curable material. The PET film was coated with a 10 mil applicator and dried at 120 ° C. for 10 minutes to form a resin composition layer. Next, it was cured by heating in an oven at 200 ° C. for 30 minutes.

  The properties of the curable material, the resin composition and the cured product were evaluated by the following methods.

«Gel fraction»
After measuring the weight of the resin composition obtained by drying at 120 ° C. for 10 minutes or the cured product obtained by further heating at 200 ° C. for 30 minutes (Weight 1), curing is performed by sandwiching it between the metal mesh and the metal mesh The materials were not overlapped and refluxed in methyl ethyl ketone (MEK) for 3 hours. After drying at 80 ° C. for 30 minutes, the weight of the cured product was measured (weight 2). The gel fraction was determined from the following equation and evaluated in two steps.

Gel fraction (%) = {1- (weight 1-weight 2) / weight 1}} × 100

○: gel fraction is 90% or more Δ: gel fraction is 30% or more to less than 90% ×: gel fraction is less than 30%

«Heat response»
Thermal responsiveness was evaluated in two steps based on the result of gel fraction measurement.
Good: The gel fraction at 120 ° C. for 10 minutes is less than 30%, and the gel fraction at 200 ° C. for 30 minutes is 90% or more x: The gel fraction at 120 ° C. for 10 minutes is 30% or more, and 200 ° C. for 30 minutes 90% or more of gel fraction in

«Preservation stability»
The state of the curable material was visually observed after storing the prepared curable material at 60 ° C. for 5 days.
○: No change ×: Thickening or gelation

  The results are shown in Table 2.

Table 2

  In Comparative Examples 1 to 3, the curing progressed under the solvent drying conditions. In addition, the storage stability at 60 ° C. was extremely bad. This is considered to be due to the structure having an epoxy group at the molecular end.

  From the above results, by using the internal epoxy compound having an epoxy group inside the molecule of the present invention, it is excellent in storage stability when compounded with an acid anhydride or a polycarboxylic acid resin, and does not react at low temperature heating and high temperature It was possible to provide an epoxy compound and a thermosetting composition that exhibit excellent thermal responsiveness that reacts only when heated.

Examples of applications of the resin composition of the present invention include a coating agent, an adhesive, a sealing material, or a raw material of molded articles such as parts, sheets, laminates, composites, etc. for the purpose of reflection prevention and protection. .
Moreover, as a use of the hardened | cured material obtained by hardening the composition of this invention, the use as materials of optical components, such as a lens, a prism, a waveguide, a board | substrate, a laminated material, a composite material, and an electronic component, is illustrated. Ru.
In particular, it can also be used for optical components such as lenses and waveguides, their adhesives, sealants, etc. by taking advantage of the characteristics such as transparency and high refractive index of the obtained cured product.

Claims (5)

A thermosetting composition comprising an internal epoxy compound having an epoxy group in the inside of a molecule, and a polycarboxylic acid or acid anhydride-based curing agent, which is represented by the following general formula (1) .
General formula (1)

(Wherein, X represents a monovalent aliphatic hydrocarbon group,
n represents an integer of 3 to 6; ) The thermosetting composition according to claim 1, wherein X is a monovalent aliphatic hydrocarbon group of 1 to 10 carbon atoms . The thermosetting composition according to claim 1, further comprising an epoxy compound other than the internal epoxy compound according to claim 1 . The heat according to any one of claims 1 to 3 , wherein the molar ratio of the epoxy group in the composition to the carbonyl group of the polycarboxylic acid resin or acid anhydride curing agent is 1: 0.4 to 1: 1.5. Curable composition. A cured product obtained by curing the thermosetting composition according to any one of claims 1 to 4 .