JPH032370B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a thermosetting composition that gives a cured product with little odor, excellent curability at room temperature, and excellent heat resistance. BACKGROUND OF THE INVENTION Room temperature curable epoxy resin compositions are widely used for paints, adhesives, casting, etc. However, conventionally used room-temperature curing epoxy resin compositions have a strong odor, absorb carbon dioxide gas in the air during curing, resulting in curing failure, and the resulting cured product has poor heat resistance. Its use was limited due to the lack of use. In order to solve these drawbacks, it has been proposed to increase the molecular weight of the curing agent or to use an aromatic amine compound as the curing agent, and some of these have been put into practical use. However, their use increases the viscosity of the resin composition, causing new problems in terms of workability, reducing the heat resistance of the cured product, and slowing down the curing speed. There is. For example, a composition consisting of meta-aminobenzylamine and bisphenol A diglycidyl ether has been proposed (US Pat. No. 3,317,468), but this type of composition has a slow curing rate at room temperature;
Another disadvantage is that the resulting cured product has poor heat resistance. Problems to be Solved by the Invention Therefore, as a result of intensive study, the present inventors changed to bisphenol A diglycidyl ether, an epoxy resin having three or more epoxy groups in one molecule.
By using an epoxy resin consisting of 100 to 30% by weight and 0 to 70% by weight of an epoxy resin having two or less epoxy groups in one molecule, the above drawbacks are improved, the room temperature curing speed is fast, and the heat resistance is high. It has also been found that thermosetting compositions with significantly improved properties can be obtained. However, meta-aminobenzylamine, which is used as one of the curing agents, has a melting point of about 40°C;
It is solid at room temperature and has poor uniformity in mixing into compositions.
When mixing is insufficient, the reaction with the epoxy resin does not proceed uniformly and quickly, resulting in insufficient adhesion, paint adhesion, and molded product strength. Therefore, attempts have been made to use an appropriate organic solvent, but this poses safety and pollution problems when volatilizing the organic solvent during curing, and also causes air bubbles to form in the resin part, resulting in poor adhesion and paint adhesion. Deteriorates the strength of the molded product. Also, attempts have been made to modify meta-aminobenzylamine and use it as a liquid adduct, but conventional examples have resulted in poor adhesion and have not been satisfactory. The present inventor focused on the fact that para-aminobenzylamine is liquid at room temperature, and tried using it for adhesives, paints, cast products, etc., and found that the reaction with epoxy resin proceeded uniformly and quickly, and meta-aminobenzylamine It has been found that it can exhibit room temperature curability and heat resistance equivalent to or higher than that of benzylamine. Furthermore, when mixed with meta-aminobenzylamine, the melting point is lower than that of para-aminobenzylamine due to melting point depression, and the reactivity is much better than that of conventional meta-aminobenzylamine alone, so the curing time is reduced. It has been found that the heat resistance is improved. The present invention was completed based on this knowledge. Means/Action for Solving the Problems The present invention provides: (1)(a) 100 to 30% by weight of an epoxy resin having 3 or more epoxy groups in one molecule;
Epoxy resin with 0 or less epoxy groups
A thermosetting composition characterized by containing an epoxy resin comprising ~70% by weight, and (b) para-aminobenzylamine, and (2) (a) three or more epoxy groups in one molecule. 100-30% by weight of epoxy resin with
Epoxy resin with 0 or less epoxy groups
This is a thermosetting composition characterized by containing an epoxy resin of ~70% by weight, and (b) para-aminobenzylamines and meta-aminobenzylamines. Hereinafter, the structure of the invention will be explained in detail together with its operation. Examples of the epoxy resin of the present invention include the following. (i) Amine-based epoxy resin

[Formula] An epoxy resin having a group, such as N, N, N', N'-tetraglycidyldiaminodiphenylmethane, meta-N,
Compounds having a simino group or amide group such as N-diglycidyl diaminodiphenyl glycidyl ether, N, N, N', N'-tetraglycidyl terephthalamide, etc., and epihalohydrins such as epichlorohydrin, methylepichlorohydrin, epibromhydrin, etc. synthesized from Specific examples of compounds having an amino group include:
Diaminodiphenylmethane, meta-xylylene diamine, para-xylylene diamine, meta-aminobenzylamine, para-aminobenzylamine,
1,3-bisaminomethylcyclohexane,
1,4-bisaminomethylcyclohexane,
1,3-diaminocyclohexane, 1,4-diaminocyclohexane, metaphenylenediamine, paraphenylenediamine, benzylamine, diaminodiphenyl sulfone, diaminodiphenyl ether, diaminodiphenyl sulfide, diaminodiphenyl ketone, naphthalene diamine , aniline, toluidine, meta-aminophenol, para-aminophenol, aminonaphthol and the like. Further, specific examples of compounds having an amide group include phthalamide, isophthalamide, terephthalamide, benzamide, toluamide, parahydroxybenzamide, metahydroxybenzamide, and the like. When a compound having an amino group or an amide group has a group that reacts with epihalohydrin, such as a hydroxyl group, a carboxyl group, or a mercapto group other than the amino group or amide group, part or all of the group that reacts with epihalohydrin reacts with epihalohydrin and may be substituted with an epoxy group. (ii) Phenol-based epoxy resin It can be synthesized from a phenol-based compound and epihalohydrin, such as bisphenol A diglycidyl ether and Epotote YDCN-220 (product of Toto Kasei Co., Ltd.). Specific examples of phenolic compounds include phenol, cresol, butylphenol, octylphenol, benzylphenol, cumylphenol, naphthol, hydroquinone, catechol, resorcinol, bisphenol A, bisphenol F, bisphenol sulfone, and brominated bisphenol. A, novolac resin, cresol novolac resin, tetraphenylethane, triphenylethane and the like. (iii) Alcohol-based epoxy resin Can be synthesized from alcohol-based compounds and epihalohydrin, such as trimethylolpropane triglycidyl ether and neopentyl glycol glycidyl ether. Specific examples of alcohol compounds include monohydric alcohols such as butyl alcohol and 2-ethylhexyl alcohol, ethylene glycol,
Diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, 1,4-butanediol,
1,6-hexanediol, neopentyl glycol, trimethylolpropane, glycerin, pentaerythritol, polycaprolactone, polytetramethylene ether glycol,
Polyhydric alcohols such as polybutadiene glycol, hydrogenated bisphenol A, cyclohexanedimethanol, bisphenol A/ethylene oxide adduct, bisphenol A/propylene oxide adduct, and polyester polyols made from these polyhydric alcohols and polycarboxylic acids. Examples include. (iv) Epoxidized unsaturated compounds cyclopentadiene epoxide, epoxidized soybean oil, epoxidized polybutadiene, vinylcyclohexene diepoxide, styrene oxide, Union Carbide trade name ERL-
Examples include epoxidized products of unsaturated compounds known as 4221, ERL-4234, and ERL-4299. (v) Glycidyl ester-based epoxy resins such as benzoic acid glycidyl ester, tetrahydrophthalic acid diglycidyl ester, etc.
It can be synthesized from carboxylic acid and epihalohydrin. Specific examples of carboxylic acids include monocarboxylic acids such as benzoic acid, paraoxybenzoic acid, butylbenzoic acid, adipic acid, sebacic acid, dodecanedicarboxylic acid, dimer acid, phthalic acid, isophthalic acid, terephthalic acid, and tetrahydrophthalic acid. , methyltetrahydrophthalic acid, hexahydrophthalic acid, Hett's acid, nadic acid, maleic acid, fumaric acid, trimellitic acid, benzenetetracarboxylic acid, butanetetracarboxylic acid,
Benzophenonetetracarboxylic acid, 5-(2,
Examples include polycarboxylic acids such as 5-dioxotetrahydrofuryl)-3-methyl-cyclohexene-1,2-dicarboxylic acid. (vi) Urethane-based epoxy resin It can be synthesized from the above-mentioned polyhydric alcohol, diisocyanate, and glycidol. Specific examples of diisocyanates include tolylene diisocyanate, diphenylmethane-4,
Examples include 4'-diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylene diisocyanate, and naphthalene diisocyanate. (vii) Other epoxy resins Trisepoxypropyl isocyanurate, glycidyl (meth)acrylate copolymers, and diisocyanates of the above-mentioned epoxy resins,
Examples include resins modified with dicarboxylic acids and polyhydric phenols. From the viewpoint of curing speed and heat resistance, epoxy resins having three or more epoxy groups are particularly preferred, and as types of epoxy resins, amine-based epoxy resins and phenol-based epoxy resins are particularly preferred. In the present invention, the epoxy resin alone is
Alternatively, two or more kinds can be used in combination. Specific examples of the epoxy resin used in the present invention have been listed above, but in the composition of the present invention, 100 to 30% by weight of the total epoxy resin is an epoxy resin having three or more epoxy groups in one molecule. It must be made into resin. If the amount of epoxy resin having three or more epoxy groups is less than 30% by weight, not only the curing speed of the composition of the present invention becomes slow, but also the heat resistance of the cured product decreases. In the composition of the present invention, as a curing agent for the epoxy resin, para-aminobenzylamine or para-aminobenzylamine and meta-aminobenzylamine are used, and among these, meta-aminobenzylamine, para-aminobenzylamine, and the above-mentioned These adducts, which are products obtained by reacting such epoxy resins under conditions such that the active hydrogen in the amino group is in excess with respect to the epoxy group, are included. Further, this adduct may be a separate adduct, an internal adduct, or a mixture of both. Even if these benzylamines contain the ortho form, which is usually a by-product during the production of the para or meta form, as long as it does not impair the effects of the present invention, it can be used as is without purification if it is in a small amount. No problem. The proportion of each component used in the composition of the present invention is as follows:
The hydrogen content of the amino group in para-aminobenzylamines or para-aminobenzylamines and meta-aminobenzylamines is usually 0.5 to 1.5, preferably 0.8 to 1, per epoxy group in the epoxy resin.
It is used in a ratio of 1.2 pieces. Further, as for the ratio of the combination of para-aminobenzylamines and meta-aminobenzylamines, the more the former is used, the lower the melting point of the mixture of both can be.
For example, the melting point of the latter alone is approximately 40°C;
When half of both are used, the melting point drops to about 15°C. The composition of the present invention includes xylylene diamine, isophorone diamine, 1,3-bisaminomethylcyclohexane, as a curing agent and curing accelerator,
Aminos such as diaminodiphenylmethane, polyamide resin, triethylamine, dimethylbenzylamine, imidazoles, trisdimethylaminomethylphenol, phenol, cresol, boron trifluoride amine salt, etc. may be used as long as they do not impair the effects of the present invention. Can be used in combination in some cases. Also solvents, silane and titanium coupling agents, pigments, organic and inorganic fillers, plasticizers,
Liquid rubber, thixotropic agents, leveling agents, antifoaming agents, tar, non-reactive diluents, low molecular weight polymers, glass fibers, carbon fibers, metal fibers, ceramic fibers, etc. may also be added. The composition of the present invention can be used in paints, adhesives, casting agents, sealants, molding materials, processing agents for fibers, paper, and the like. Furthermore, the composition of the present invention usually has a
Can be cured at 200℃. The present invention will be explained in more detail below using examples. In each of the following examples, parts or percentages are expressed on a weight basis unless otherwise specified. Example 1 92 parts of an amine-based epoxy resin made from meta-aminophenol and epichlorohydrin (trade name Epotote YDM-120, Toto Kasei Co., Ltd., main component has 3 epoxy groups in one molecule) and para-aminobenzyl. When the mixture was thoroughly mixed with 23 parts of amine and left at room temperature, the adhesiveness almost disappeared and the mixture was cured after 180 minutes. After leaving this cured product at room temperature for a week,
A dynamic viscoelasticity test of the cured product was conducted using a Rheovibrone tester. The glass transition temperature was determined to be 162°C as a measure of the heat resistance of the cured product.
However, the glass transition temperature was the temperature at which E'' (loss modulus of elasticity) peaked.Hereinafter, the glass transition temperature will be used in this sense.Example 2 Amine made from diaminodiphenylmethane and epichlorohydrin A phenolic epoxy resin (trade name, Epotote YH-434, Toto Kasei Co., Ltd., the main component has 4 epoxy groups in one molecule) and a phenolic epoxy resin made from bisphenol A and epichlorohydrin. Epicote 828,
Yuka Ciel Epoxy Co., Ltd., the main component (2 epoxy groups in one molecule) and meta-aminobenzylamine were mixed together as shown in Table 1, and the time until the tackiness disappeared was determined as the curing time. After curing, the sample was allowed to stand at room temperature for one week in the same manner as in Example 1, and then the glass transition temperature was determined by a dynamic viscoelasticity test.
The results are summarized in Table 1. The results of using meta-aminobenzylamine instead of para-aminobenzylamine are shown in Experiment Nos. 7 and 8 as comparative examples (* indicates meta-aminobenzylamine was used).

[Table] Example 3 Phenol-based epoxy resin made from phenol novolac resin and epichlorohydrin (trade name Epicote 154, Yuka Ciel Epoxy Co., Ltd.)
80 parts of bisphenol F diglycidyl ether (the number of epoxy groups in one molecule of the main component is 3), 20 parts of bisphenol F diglycidyl ether (the number of epoxy groups in 1 molecule of the main component is 2), and 2.5 moles of para-aminobenzylamine and ethylene glycol glycidyl ether The curing time and glass transition temperature of 31 parts of the adduct obtained by reacting 1 mole at 80° C. for 2 hours were determined in the same manner as in Example 1. The curing time was 255 minutes, and the glass transition temperature was 169°C. Example 4 Phenol-based epoxy resin made from tetraphenylethane and epichlorohydrin (trade name: Epicote 1031, Yuka Ciel Epoxy Co., Ltd., main component has 4 epoxy groups in one molecule) 85 parts, vinyl The curing time and glass transition temperature were determined in the same manner as in Example 1 using 15 parts of cyclohexene diepoxide (2 epoxy groups in one molecule) and 19 parts of para-aminobenzylamine. The curing time was 180 minutes, and the glass transition temperature was 187°C. Example 5 40 parts of Epicote 1031, 7 parts of vinylcyclohexene diepoxide, 53 parts of Epotote YH-434,
and 22 parts of para-aminobenzylamine in Example 1.
The curing time and glass transition temperature were determined in the same manner as above. The curing time was 140 minutes, and the glass transition temperature was 193°C. Example 6 An experiment similar to Example 1 was conducted using the following composition. Epotote YH-434 43 parts Vinylcyclohexene diepoxide 5 parts Aminobenzylamine 13 parts o-ABA 2.8% m-ABA 48.3% p-ABA 48.5% The curing speed was 120 minutes, and the glass transition temperature was 192°C. Effects of the Invention As detailed above, the thermosetting composition of the present invention has a high curing speed and excellent heat resistance, and the aminobenzylamine used as a curing agent is m
Since it can be used as a mixture of -, p-, and p-, the economic effect is also extremely large.

Claims (1)

[Scope of Claims] 1 (a) 100 to 30% by weight of an epoxy resin having 3 or more epoxy groups in one molecule, 2 to 30% by weight in one molecule;
Epoxy resin with 0 to 3 epoxy groups
1. A thermosetting composition comprising: an epoxy resin containing 70% by weight; and (b) para-aminobenzylamine. 2 (a) 100 to 30% by weight of epoxy resin having three or more epoxy groups in one molecule, two or more in one molecule.
Epoxy resin with 0 to 3 epoxy groups
1. A thermosetting composition comprising: an epoxy resin containing 70% by weight; and (b) para-aminobenzylamines and meta-aminobenzylamines.