JP3476994B2 - Epoxy resin composition - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an epoxy resin composition having a long-term storage property at room temperature and a rapid curability upon heat curing.

[0002]

2. Description of the Related Art The present inventors have previously prepared a latent curing agent for an epoxy resin by using a nitrogen-containing heterocyclic compound, an aliphatic amine or an aromatic amine as an epoxy compound having one or more epoxy groups in one molecule. A latent curing agent in which a boric acid ester compound is coated on the surface of a reacted epoxy adduct (hereinafter referred to as an epoxy adduct) and an epoxy resin composition containing the curing agent and a phenolic compound have been proposed. (JP-A-6-172495)

However, when an epoxy adduct surface-treated with a boric acid ester compound and a phenolic compound are allowed to coexist, alcohol is generated during preparation of the compound and curing of the epoxy resin, and the volatilization thereof causes the epoxy resin cured product to have characteristics. However, there was a problem that the work environment was deteriorated due to the bad influence of the above and the smell of alcohol.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an epoxy resin composition which, when an epoxy adduct is used as an epoxy curing agent, does not generate alcohol and has sufficient storage stability and curing performance. Is what you are trying to do.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies focusing on the fact that alcohol is generated from the alkoxy group of boric acid ester, and found that boric acid and an aliphatic or aromatic diol are used. It was found that the intended object can be achieved by using the obtained cyclic ester compound, and further, when the epoxy adduct surface is coated with the cyclic borate compound, no alcohol is generated and the storage stability is stable. Further, they have found that an epoxy resin composition having excellent curing characteristics can be obtained, and have completed the present invention.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The powdery epoxy adduct used in the practice of the present invention is obtained by pulverizing a product obtained by the addition reaction of an alkylamine, an aromatic amine or a nitrogen-containing heterocyclic compound with an epoxy resin by a known method. It was obtained by doing. Further, the cyclic boric acid ester compound suitable for carrying out in the present invention has the general formula shown in Chemical formulas 10 to 12.

[0007]

[Chemical 10] (R ₁ is a hydrogen atom, an alkyl group or an aryl group, R
₂ represents an alkylene group or an aryl group. )

[0008]

[Chemical 11] (R ₃ and R ₄ represent an alkylene group or an aryl group.)

[0009]

[Chemical 12] (R ₅ , R ₆ and R ₇ represent an alkylene group or an aryl group.)

Typical examples of these cyclic borate ester compounds are tris-o-phenylene bisborate, bis-o-phenylene pyroborate and bis-2,3.
-Dimethyl ethylene pyroborate, bis-2,2-dimethyl trimethylene pyroborate and the like.

A typical nitrogen-containing heterocyclic compound used in the practice of the present invention is 2-ethyl-
4-methylimidazole, 2-methylimidazole, 2
-Phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenyl-4
-Methyl-5-hydroxymethylimidazole and 2-
Imidazole compounds such as phenyl-4,5-dihydroxymethylimidazole, 2-phenylimidazoline, 2
-Imidazoline compounds such as heptaiimidazoline and 2-heptadecyl imidazoline, mercaptobenzothiazoles, and melamine derivatives.

Typical examples of the aliphatic amine compound and the aromatic amine compound are diethylenetriamine, triethylenetetramine, tetraethylenepentamine, iminobispropylamine (dipropylenetriamine), bis (hexamethylene) triamine, Diaminodiphenylmethane, metaphenylenediamine and 3,9-
Examples thereof include bis (3-aminopropyl) -2,4,8,10-tetraspiro [5,5] undecane.

Typical examples of the epoxy compound having one or more epoxy groups in one molecule used in the practice of the present invention include bisphenol A type epoxy resin, bisphenol F type epoxy resin and cycloaliphatic epoxy. Resin, glycidyl ester-based epoxy resin, glycidyl amine-based epoxy resin, hydantoin-type epoxy resin, phenyl glycidyl ether, butyl glycidyl ether, triglycidyl isocyanurate, etc. are used alone or in combination of two or more.

Typical examples of the phenolic compound used in the epoxy resin composition of the present invention include catechol, 4-t-butylcatechol, pyrogallol, resorcin, hydroquinone, phloroglucinol, bisphenol A, bisphenol F and dihydroxy. Biphenyl, dihydroxynaphthalene, 1,1,1-tris (4
Compounds such as -hydroxyphenyl) ethane and bis (4-hydroxyphenyl) sulfone, novolac-type or resol-type phenolic resins, and phenolic polymers such as polyvinylphenol.

In the practice of the present invention, the method described below is suitable for mass production in order to prepare an epoxy resin composition. [Method A] A method in which an epoxy adduct , a cyclic boric acid ester compound and a phenolic compound are separately added to an epoxy resin, and the resulting mixture is kneaded using a planetary mixer or a roll. [Method B] A method in which the surface of the epoxy adduct is coated with a cyclic boric acid ester compound in advance, and then the epoxy resin is kneaded with the phenolic compound. [Method C ] A method in which a cyclic borate compound and a phenol compound are coated on an epoxy adduct using a spray dryer or the like and then kneaded with an epoxy resin.

In the production of the epoxy resin composition of the present invention, the compounding amount of the cyclic borate ester compound is 0.01 to 100 parts by weight, preferably 0.25 to 30 parts by weight, relative to 100 parts by weight of the epoxy adduct. It is a department. If the addition amount of these is less than 0.01 parts by weight, it is difficult to secure the latent property, and if it exceeds 100 parts by weight, curing failure is induced, such being undesirable.

When the surface-treated epoxy adduct is compounded, it is in the range of 0.5 to 50 parts by weight, preferably 1 to 25 parts by weight, based on 100 parts by weight of the epoxy resin. The speed and latent curability can be secured.

The blending ratio of the phenolic compound is 0.001 to 50 parts by weight, preferably 0.05 to 10 parts by weight, based on 100 parts by weight of the epoxy resin.

In the practice of the present invention, an epoxy resin composition having excellent storage stability can be obtained also in a curing system in which another epoxy curing agent such as an acid anhydride is added to the above epoxy resin composition. Typical examples of the curing agent used at that time include maleic anhydride, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, succinic anhydride, methyl nadic acid anhydride, and chlorendec anhydride. In addition, there are dicyandiamide, organic acid hydrazide, diaminomaleonitrile, diallyl melamine and amine imide.

In preparing the epoxy resin composition,
In addition to curing agents or curing accelerators, additives such as antioxidants, various particulate and fibrous fillers, plasticizers, reactive diluents, colorants, and viscosity modifiers are used as necessary. It doesn't matter.

The present invention will be specifically described below with reference to Examples and Comparative Examples. In the practice of the present invention, the epoxy resin, nitrogen-containing heterocyclic compound, phenolic compound and silica used as raw materials are as follows.

(1) Epoxy resin Product name: Epicoat # 828, manufactured by Yuka Shell Co., Ltd. Product name: Epicoat # 152, manufactured by Yuka Shell Co., Ltd. Product name: DER-438, Dow Chemical Japan Co., Ltd. Product name: DER-331J, Dow Chemical Japan Co., Ltd. product name: ERL-4221, Union Carbide Japan Co., Ltd.

(2) Nitrogen-containing heterocyclic compound 2-ethyl-4-methylimidazole (hereinafter 2E4
MZ): Trade name "Curezol 2E4MZ" Shikoku Chemicals Co., Ltd. 2-phenylimidazole (hereinafter referred to as 2PZ):
Product name "Curesol 2PZ" manufactured by Shikoku Chemicals Co., Ltd.

(3) Phenolic compound Product name: Red Top, Gunei Chemical Industry Co., Ltd. Product name: Resin X, Mitsubishi Petrochemical Co., Ltd. Product name: Resin M, manufactured by Maruzen Petrochemical Co., Ltd. (4) Silica Product name: Aerosil # 300, manufactured by Nippon Aerosil Co., Ltd.

[0025]

EXAMPLE An epoxy resin composition was prepared by the above method A,
The storage stability of the epoxy resin composition is represented by the number of days until the initial viscosity of the composition reaches double at room temperature, and the gelation time is the heat retention at a temperature of 150 ° C. On the plate, it was determined by the stroke cure method. The amount of alcohol generated was quantified by GC-MS analysis using the head space method (heating at 120 ° C. for 20 minutes).

Examples 1 to 4 and Comparative Examples 1 and 2 Epoxy resins, epoxy adducts and surface treatment agents shown in Table 1 were mixed in the respective prescribed proportions according to the above method A,
An epoxy resin composition was prepared. When the storage stability and the amount of alcohol generated of the obtained epoxy resin composition were measured, the results were as shown in Table 1.

[0027]

[Table 1]

[Examples 5 to 9 and Comparative Examples 3 and 4] The epoxy resin, the curing agent, the epoxy adduct and the surface treatment agent shown in Table 2 were mixed at a predetermined ratio according to the above method B to prepare an epoxy resin. A resin composition was prepared. When the storage stability and the amount of alcohol generated of the obtained epoxy resin composition were measured, the results were as shown in Table 2.

[0029]

[Table 2]

[Examples 10 to 19] Epoxy resins, epoxy adducts and surface treatment agents were mixed in the proportions shown in Table 3 to prepare epoxy resin compositions. When the gelation time, storage stability and alcohol generation amount of the obtained epoxy resin composition were measured, the results were as shown in Table 3.

[0031]

[Table 3]

[Examples 20 to 23] Epoxy resins, epoxy adducts, bis-dimethylethylene pyroborate and resin tops were mixed in proportions shown in Table 4,
An epoxy resin composition was prepared. The gelation time, storage stability and alcohol generation amount of the obtained epoxy resin composition were measured, and the results were as shown in Table 4.

[0033]

[Table 4]

[ Examples 24-26] An acetone solution containing a cyclic oxalate compound and a resist as a spray treating agent was prepared in the proportions shown in Table 5 and sprayed onto a powdery epoxy adduct. By drying, powder of coated epoxy adduct was obtained. Then, the epoxy resin and the coated epoxy adduct were kneaded in the proportions shown in Table 6 by the method C to prepare an epoxy resin composition. The gelation time, storage stability and amount of alcohol generated of the obtained epoxy resin composition were measured, and the results were as shown in Table 6.

[0035]

[Table 5]

[0036]

[Table 6]

Comparative Examples 5 to 7 Tris-o-phenylene bisborate, bis-2,2-dimethyltrimethylene pyroborate or Resitop was used in the mixing ratio shown in Table 5, and the surface of the epoxy adduct was An epoxy resin composition was prepared by mixing the surface-treated epoxy adduct and the epoxy resin in the proportions shown in Table 7 after treating by the method A. The gelation time, storage stability and alcohol generation amount of the obtained epoxy resin composition were measured, and the results were as shown in Table 7.

[0038]

[Table 7]

[0039]

The latent epoxy curing agent of the present invention is capable of imparting excellent curing characteristics as an epoxy curing agent and extremely good storage stability as compared with conventional products without deteriorating the working environment. The epoxy resin composition containing a latent epoxy curing agent as an essential component is an adhesive, a sealing material,
When used as a material such as an ink or a paint, it is possible to provide a cured product which is easy to handle and has excellent mechanical properties and the like.

Continuation of the front page (56) Reference JP-A-6-172495 (JP, A) JP-A-2-103224 (JP, A) JP-A-1-132652 (JP, A) JP-A-58-85238 (JP , A) JP 6-211969 (JP, A) JP 57-185316 (JP, A) JP 9-157498 (JP, A) JP 58-75857 (JP, A) JP 6-73156 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08G 59/14 C08G 59/40 C08G 59/50 C08G 59/62

Claims (3)

(57) [Claims] 1. A nitrogen-containing heterocyclic compound to an epoxy compound having an epoxy group 1 or 2 or more in one molecule, the epoxy adduct obtained by reacting one of the aliphatic amine or aromatic amine, of 1, of An epoxy resin composition comprising a cyclic borate compound represented by formula 2 or formula 3 and a phenol compound compounded in an epoxy resin. [Chemical 1] (R ₁ is a hydrogen atom, an alkyl group or an aryl group, R
₂ represents an alkylene group or an aryl group. ) [Chemical 2] (R ₃ and R ₄ represent an alkylene group or an aryl group.) (R ₅ , R ₆ and R ₇ represent an alkylene group or an aryl group.) 2. The surface of an epoxy adduct obtained by reacting an epoxy compound having one or more epoxy groups in one molecule with a nitrogen-containing heterocyclic compound, an aliphatic amine or an aromatic amine, 4, Chemical 5 or Chemical 6
An epoxy resin composition comprising a latent epoxy curing agent obtained by coating the cyclic borate compound represented by and a polyhydric phenol compound in an epoxy resin. [Chemical 4] (R ₁ is a hydrogen atom, an alkyl group or an aryl group, R
₂ represents an alkylene group or an aryl group. ) [Chemical 5] (R ₃ and R ₄ represent an alkylene group or an aryl group.) (R ₅ , R ₆ and R ₇ represent an alkylene group or an aryl group.) 3. The surface of an epoxy adduct obtained by reacting an epoxy compound having one or more epoxy groups in one molecule with a nitrogen-containing heterocyclic compound, an aliphatic amine or an aromatic amine , 7, chemical 8 or chemical 9
An epoxy resin composition comprising a latent epoxy curing agent obtained by coating a cyclic boric acid ester compound and a phenolic compound represented by the above formula with an epoxy resin. [Chemical 7] (R ₁ is a hydrogen atom, an alkyl group or an aryl group, R
₂ represents an alkylene group or an aryl group. ) [Chemical 8] (R ₃ and R ₄ represent an alkylene group or an aryl group.) (R ₅ , R ₆ and R ₇ represent an alkylene group or an aryl group.)