JPH032371B2 - - 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, low-temperature workability, 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.
If the mixing is insufficient, the reaction with the epoxy resin will 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 molded product strength. Also, attempts have been made to modify meta-aminobenzylamine and use it as a liquid adduct, but the conventional examples have resulted in poor adhesion and have not been satisfactory. Therefore, the present inventor found that the curability and heat resistance could be further improved by using para-aminobenzylamine alone or in combination with meta-aminobenzylamine, and the present applicant filed an application earlier. The present invention relates to a thermosetting composition that has further improved curability at room temperature, low-temperature workability, heat resistance of cured product, heat deterioration resistance, and toughness. That is, the present invention focuses on the fact that by mixing aromatic diamines in a certain proportion not only with meta-para mixture of aminobenzylamine but also with meta-aminobenzylamine alone, the mixture becomes liquid at room temperature. Attempts were made to use it in adhesives, paints, cast products, etc. Although aromatic diamines do not show curing properties alone at room temperature, when mixed with aminobenzylamines, the reaction with epoxy resins proceeds uniformly and quickly, and the reaction rate is the same or higher than that of aminobenzylamines. It has been discovered that it can exhibit room temperature curability and heat resistance. Furthermore, they discovered that the addition of antimony trioxide is extremely effective in preventing thermal deterioration, and that the addition of acrylic, silicone, etc. rubbers is extremely effective in improving impact resistance. This completes the present invention. 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
1. A thermosetting composition comprising: an epoxy resin containing up to 70% by weight; and (b) aminobenzylamines and aromatic diamines. (2)(a) 100-30% by weight of epoxy resin having 3 or more epoxy groups in one molecule, 2% by weight in 1 molecule
Epoxy resin with 0 or less epoxy groups
1. A thermosetting composition comprising: an epoxy resin comprising ~70% by weight; (b) aminobenzylamines and aromatic diamines; and (c) antimony trioxide. (3)(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 or less epoxy groups
1. A thermosetting composition comprising: an epoxy resin comprising ~70% by weight; (b) aminobenzylamines and aromatic diamines; and (c) rubber. (4)(a) 100-30% by weight of epoxy resin having 3 or more epoxy groups in one molecule, 2% in 1 molecule
Epoxy resin with 0 or less epoxy groups
A thermosetting composition comprising: an epoxy resin comprising ~70% by weight, (b) aminobenzylamines and aromatic diamines, (c) antimony trioxide, and (d) rubber. , is. Hereinafter, the structure of the invention will be explained in detail along 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 an amino group or amide group such as N-diglycidyldiaminophenylglycidyl ether, N,N,N',N'-tetraglycidyl terephthalamide, and epichlorohydrin,
It is synthesized from epihalohydrins such as methylepichlorohydrin and epibromohydrin. 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, meta-hydroxybenzamide, 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 may react with epihalohydrin and 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 diglycidyl 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 diepoxide, 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, polyhydric phenols, and the like. 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, epoxy resins can be used alone or in combination of two or more. 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, aminobenzylamines, mainly para-aminobenzylamines, meta-aminobenzylamines, and mixtures thereof, are used as curing agents for epoxy resins. These adducts are included, which are products obtained by reacting an amine with an epoxy resin such as those described above under conditions such that the active hydrogen in the amino group is in excess with respect to the epoxy group. 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. Next, aromatic diamines used as curing agents for epoxy resins together with aminobenzylamines are represented by the following general formula.

[Formula] However, R ₁ , R ₂ and R ₃ are the same or different alkyl groups having 1 to 5 carbon atoms. For example, 3,5-diethyltoluene-2,4
-diamine or 3,5-diethyltoluene-2,
6-diamine is used alone or in combination. Also, 60 to 90% by weight of a compound in which R ₁ is a methyl group, R ₂ and R ₃ are an ethyl group, and 40 to 10% by weight of a compound in which R ₁ and R ₂ are an ethyl group and R ₃ is a methyl group are mixed. Can be used. Aromatic diamines do not cure at room temperature even when used alone as curing agents for epoxy resins, and do not cure unless heated. Demonstrates excellent room temperature curability when used in combination with aminobenzylamines. Therefore, the mixing ratio of aminobenzylamines and aromatic diamines is 95
From 5 to 50 parts by weight, preferably from 20 to 50 parts by weight, of aromatic diamines are used for ~50 parts by weight. If the mixing ratio of aromatic diamine exceeds 50 parts by weight, the curing rate will decrease, which is not preferable. Furthermore, at the above mixing ratio, the melting point of the mixture decreases and it liquefies at room temperature, so there is no need to heat and melt it when reacting with the epoxy resin, improving workability, improving heat resistance, and achieving a Tg of 10 to 20℃.
will also rise. In the composition of the present invention, the ratio of the epoxy resin and curing agent used is usually 0.5 to 1 epoxy group in the epoxy resin to 0.5 hydrogen of the amino group in the aminobenzylamines and aromatic diamines. -1.5, preferably 0.8-1.2. Next, by adding antimony trioxide (Sb ₂ O ₃ ) to the above-mentioned thermosetting composition, the heat deterioration resistance of the cured product is greatly improved. The amount added is preferably 5 to 50 parts by weight per 100 parts by weight of the epoxy resin. If the amount added is less than 5 parts by weight, the effect will not be sufficiently expressed, and if it exceeds 50 parts by weight, the adhesive strength will decrease. In the present invention, in order to improve the toughness of the cured product, it is preferable to mix rubber. As rubber,
Examples include acrylic ester-based, silicone-based, conjugated diene-based, olefin-based, polyester-based, and urethane-based polymers, with acrylic ester-based, silicone-based, and conjugated diene-based polymers being particularly preferred. These may be used alone or in combination. Acrylic ester rubbers are disclosed, for example, in JP-A-55-16053 and JP-A-55-21432. Silicone rubbers are disclosed, for example, in Japanese Patent Application No. 180821/1982. In addition, examples of conjugated diene rubber include:
It can be produced by polymerizing or copolymerizing monomers such as 1,3-butadiene, 1,3-pentadiene, isoprene, 1,3-hexadiene, and chloroprene, and commercially available products can be used. The amount of rubber used is 5 to 40 parts by weight, preferably 12 to 35 parts by weight, based on 100 parts by weight of the epoxy resin. The rubber may be dissolved or dispersed in the epoxy resin. Alternatively, it may be dissolved in an epoxy resin and precipitated as particles upon curing. Alternatively, a graft copolymer with an epoxy resin may be used. 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 amino-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 19 parts of amine and 5 parts of 3,5-diethyltoluene and 2,4-diamine were thoroughly mixed and allowed to stand at room temperature, tackiness almost disappeared after 170 minutes and the mixture was cured. After this cured product was left at room temperature for one week, a dynamic viscosity test of the cured product was conducted using a Rheovibrone tester. The glass transition temperature was determined to be 175°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 epoxy resin (trade name Epotote YH-434, Toto Kasei Co., Ltd., main component 1)
(4 epoxy groups in the molecule) and a phenolic epoxy resin made from bisphenol A and epichlorohydrin (trade name: Epicote 828, Yuka Ciel Epoxy Co., Ltd., the main component is 2 epoxy groups in one molecule) ) and aminobenzylamine and toluene diamine (a mixture of 78% 3,5-diethyltoluene 2,4-diamine and 22% 3,5-diethyltoluene 2,6-diamine) were mixed in the amounts shown in Table 1. The time required for the adhesive to disappear 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 in Table 1
summarized in.

[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 meta-aminobenzylamine and 19.8 parts of an adduct obtained by reacting 1 mol of glycidyl ether at 80°C for 2 hours and 3,5-
The curing time and glass transition temperature were determined in the same manner as in Example 1 using 8.5 parts of diethyltoluene 2,4-diamine. Curing time is 230 minutes, glass transition temperature is 182℃
It was hot. Example 4 Phenolic epoxy resin made from tetraphenylethane and epichlorohydrin (trade name: Epicote 1031, Yuka Ciel Epoxy Co., Ltd.)
(There are 4 epoxy groups in one molecule of the main component) 85 parts,
15 parts of vinylcyclohexene diepoxide (2 epoxy groups in 1 molecule), 13.1 parts of meta-aminobenzylamine and 8.7 parts of 3,5-diethyltoluene 2,4-diamine were added in the same manner as in Example 1, and the curing time was , the glass transition temperature was determined. The curing time was 170 minutes, and the glass transition temperature was 198°C. Example 5 40 parts of Epicote 1031, 7 parts of vinylcyclohexene diepoxide, 53 parts of Epotote YH-434,
The curing time and glass transition temperature were determined in the same manner as in Example 1 using 12.1 parts of meta-aminobenzylamine, 6.5 parts of para-aminobenzylamine, and 7.5 parts of 3,5-diethyltoluene 2,4-diamine. The curing time was 130 minutes, and the glass transition temperature was 209°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 8.9 parts o-ABA 2.8% m-ABA 48.3% p-ABA 48.5% 3,5-diethyltoluene 2,4-diamine 95%
and 3,5-diethyltoluene 2,4-diamine 5
% and 6.0 parts The curing speed was 110 minutes and the glass transition temperature was 195°C. Example 7 23 parts of antimony trioxide was further added to the same amount of epoxy resin and curing agent as in Example 1, mixed well, and left at room temperature. After 170 minutes, almost no stickiness was left and the mixture was cured. then in the air
The material was kept at 200°C for a long period of time, and its tensile shear strength at 20°C (according to JISK6850) was measured to investigate thermal deterioration. The results are summarized in Table 2. A cold rolled steel plate (JISG3141) SPCC-SD (1.6 mm thick) was used as the adherend.

[Table] The tensile shear strength decreases less with the addition of antimony trioxide than with the addition of antimony trioxide. Example 8 The following rubber components were synthesized. Phenolic epoxy resin made from phenol novolac resin and epichlorohydrin (trade name: Epicote 152, Yuka Ciel Epoxy Co., Ltd.)
There are 2 epoxy groups in one molecule of the main component) 500 parts,
Add 9 parts of acrylic acid and 1 part of triethylamine,
Epoxy resin 509 with acrylic acid residue introduced by heating to 110℃ and reacting for 8 hours
The section was manufactured. Next, 370 parts of butyl acrylate, 1 part of azobisdimethylvaleronitrile, and 2 parts of azobisisobutyronitrile were added to this, and the mixture was heated at 70°C for 3 hours.
A graft polymer of epoxy resin and acrylic ester was produced by carrying out a polymerization reaction at 90°C for 1 hour. (This is referred to as A1.) The following experiment was conducted with the following composition. Epotote YH-434 43 parts Vinyl cyclohexene diepoxide 5 parts A1 33 parts Aminobenzylamine (2.8% o-form, m-form
48.3%, p-isomer 48.5%) 13.8 parts 3,5-diethyltoluene 2,4-diamine
2.7 parts 3,5-diethyltoluene 2,6-diamine
0.8 part JISK6855 Izotsu impact strength (material of test piece
JISG4051−S10C) was measured and found to be 12.0Kg・
cm/ ^cm2 . On the other hand, in the case of Example 6 which did not contain rubber, the impact strength was 6.0 Kg·cm/cm ² and a considerable improvement in impact strength was observed. Effects of the Invention As detailed above, the thermosetting composition of the present invention has a high curing speed and excellent heat resistance, heat deterioration resistance, and impact 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 comprising 70% by weight, and (b) aminobenzylamines and aromatic diamines. 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: 70% by weight of an epoxy resin; (b) aminobenzylamines and aromatic diamines; and (c) antimony trioxide. 3 (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: 70% by weight of an epoxy resin; (b) aminobenzylamines and aromatic diamines; and (c) rubber. 4 (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: 70% by weight of an epoxy resin; (b) aminobenzylamines and aromatic diamines; (c) antimony trioxide; and (d) rubber.