JPS61293218A - Epoxy resin curing agent - Google Patents

Abstract

PURPOSE:An epoxy resin curing agent having good compatibility with epoxy resins and a high activity, obtained by the intermolecular dehydrohalogenation between a guat. phosphonium halide and an activated hydrogen-containing imino compound and represented by the specified formula. CONSTITUTION:This curing agent has, as an effective component, at least one compound belonging to a quat. phosphonium compound and selected from among a phosphonium benzotriazolate compound of formula I (wherein R1, R2, R3 and R4 are each alkyl, alkenyl, aryl or benzyl, R5 is H or methyl), a phosphonium benzosulfimidate compound of formula II (wherein R1, R2, R3 and R4 are as defined in formula I), and a phosphonium phthalimidate compound of formula III (wherein R1, R2, R3 and R4 are as defined in formula I).

Description

[Detailed description of the invention] The present invention uses a quaternary phosphonium compound as an active ingredient.

This invention relates to epoxy resin curing agents.

The phosphonium compound is obtained by intermolecular dehydrohalogenation between a quaternary phosphonium halide and an imino compound having activated hydrogen, and the detailed reaction is shown by formulas α] to (3). It is synthesized according to the reaction formula.

[(1) above, @, (3) formula middle horse, R,, bird,
R represents an alkyl group, an alkenyl group, an aryl group, or a benzyl group; R represents a hydrogen atom or a methyl group; and X represents a halogen atom. ] The present invention has been developed as a result of an interest in the reaction between a quaternary phosphonium halide and an imino compound having activated hydrogen, and the result of intensive research.

The phosphonium compound according to the present invention differs from the general concept of phosphonium compounds in that it has a quaternary phosphonium cation as a cation fraction, a strong electrolyte norogen ion as an anion component, and a solate anion as an anion component. It is something that you have. The characteristics of the phosphonium acylate will be described below.

1. Compared to general quaternary phosphonium halides, it is poorly soluble in water and extremely well soluble in organic solvents and epoxy resins.

2 It is decomposed by acid and separated into the constituent phosphonium compounds and triazole compounds or imide compounds.

λ Stable to water and heat.

By utilizing the above properties, we have found that the phosphonium compound can be used as an epoxy resin curing agent.

It is a well-known fact that the quaternary phosphonium halide, which is the raw material for the phosphonium compound, acts as an epoxy resin curing agent; Because of this, it has poor compatibility with epoxy resins, and also has the drawback that halogen ions, which are strong electrical waste substances, are incorporated into the cured resin, which significantly impairs the electrical insulation properties of the cured resin.

However, since the anion component of the phosphonium compound is a lipophilic acylate ion, it has good compatibility with the epoxy resin, and the weak electrolyte ion does not impair the electrical insulation properties of the cured resin.

Since this compound is a salt of a phosphonium cation, which is a strong base, and an acylate anion, which is a weak acid, the quaternary phosphonium halide, which is a neutral salt, has strong activity as an epoxy resin curing agent and significantly extends the pot life. It also has the characteristic of not reducing heat curability. The present invention deals with cases in which the quaternary phosphonium acylate compound 7 is used alone as a curing agent, and other curing agent components, such as aliphatic polyamines, aromatic polyamines, azun salts, dicyandiamide, imidazole compounds, polyamides, etc. Carboxylic acid anhydride, polyhydric phenol 1. It also includes combination use with hydrazide compounds and the like.

The polyepoxy compound in the present invention may contain more than one epoxy group on average per molecule, or may be present in the middle of the molecular formula, so that the polyepoxy compound is aliphatic or m-type aliphatic.

Aromatic groups and groups may be heterocyclic groups, and hydroxyl groups, alkyl groups, alkoxy groups, and ester groups.

It may be substituted with a non-interfering substituent such as an acetal group or an ether group.

The most desirable polyepoxy compounds are bisphenol A,
Bisphenol F, resorcinol, nohydroquinone, 4
- Polyglycidyl ethers of polyhydric phenols such as 4'-diphenol, dihydroxydiphenylsulfone, phenol-formaldehyde resin, and cresol-formaldehyde resin.

Examples of other suitable polyepoxy compounds include glycidyl ethers of polyhydric alcohols such as ethylene glyfur, propylene glycol, chrycerin, trimethylolprono(n, 1,4-butanediol), phthalic acid, tetrahydrophthalic acid, hexahydr Polyglycidyl esters of polyvalent carboxylic acids such as phthalic acid, methylendomethylenetetrahydroheptalic acid, adipic acid, dimer acid Q, aniline, glycicylamines derived from engineered polyamines such as 4,4'-diaminodiphenylmethane, vinyl Cyclohexene dioxide.

3,4-epoxycyclohexylmethyl-3@4-epoxycyclohexanecarboxylate, bis-(3,4
-epoxy-6-methylcyclohexylmethyl)-7 dibate, epoxidized polyolefin, or epoxidized vegetable oil.

In addition, specific examples of the phosphonium compound which is the epoxy resin curing agent that is the most characteristic feature of the present invention include triethylbenzylphosphonium benzotriazolate, tetra-n-butylphosphonium benzotriacylate, and tetra-n-butylphosphonium benzotriazolate. -butylphosphonium tolyl triazolate, tri-n-butylmethylphosphonium bensitriacylate, tri-n-butylallylphosphonium bensitriacylate,) U-! l-Butylhexadecylphosphonium tolyl triazolate, tri-n-octylethylphosphonium tolyl triazolate, tetraphenylphosphonium benzotriazolate, ethyltriphenylphosphonium tolyl triazolate, triethylbenzylphosphonium benzosulfimidate, tetra- n-butylphosphonium benzosulfimidate, trin-7'tylarylphosphonium benzosulfimidate,) V-n-butylhexadecylphosphonium benzosulfimidate, tetraphenylphosphonium benzosulfimidate, tetra- Examples include n-butylphosphonium phthalimidate, tri-n-butylbenzylphosphonium phthalimidate, tetraphenylphosphonium phthalimidate, and tri-n-butylallylphosphonium phthalimidate.

Additionally, the cured composition of the present invention contains a plasticizer such as dibutyl 7-talate and dioctyl phthalate.

The compositions obtained according to the invention may also contain inert organic solvents or so-called reactive diluents, especially monoepoxides such as butyl glycidyl ether, phenyl glycidyl ether, etc. , extenders, fillers, reinforcing agents and various other additives 1
For example pigments, dyes, flame retardants, thixotropic agents, anti-flow agents.

It may also contain a polymeric substance or the like as a flexibility imparting agent.

Hereinafter, embodiments of the present invention will be described by way of examples.

Example 1 Polyepoxy compound (DIR-33 manufactured by Dow Chemical Company)
1) 5 parts by weight of the curing agent of the present invention was added to 100 parts by weight and mixed at room temperature to form a melt layer.

This was heated at 80°C for 2 hours and then at 130°C for 4 hours. Heat distortion temperature of the obtained cured product.

Tensile strength and volume resistivity were measured. The results are shown in Table 1. For comparison, Table 1 below also shows the physical properties of a cured product cured in the same manner as above using a quaternary phosphonium halide compound as a substitute for the curing agent of the present invention.

Example 2 Polyepoxy compound (DER-33 manufactured by Dow Chemical Company)
1) Uniform mixture t- of 100 parts by weight and overlapping parts of curing agent 1O
Prepare. Gelation of this composition at 120°C, 40°C
Table 2 shows the pot life measurement results and the pot life-gelling time ratio determined from them.

The gelation time in the table above refers to the composition of 0.5 gr t- placed on a hot plate maintained at 120±085°C, the composition t2-3- spread on a metal plate, and the gelation time repeated once every 2 seconds. Knead while pressing uniformly at intervals] and take the time until no strings are drawn between the composition and the spatula when the spatula is lifted.

Pot life is the time taken for a composition to be stored at a temperature of t-40° C. and its viscosity change to reach 10 times its initial viscosity value. tx Botry 7 - Gel Latency Ratio is the ratio of gel time to pot life value.

Example 3 Polyepoxy compound (DER-33 manufactured by Dow Chemical Company)
1), 10 parts by weight of dicyandiamide, 1 part by weight of tetra-n-butylphosphonium benzotriacyle), and 3 parts by weight of colloidal silica. Cured by heating at -150°C for 30 minutes. The material has a heat distortion temperature of 155°C and a tensile shear strength of 195 Kf/ai.
Met.

Example 4 Polyepoxy compound (DIR-33 manufactured by Dow Chemical Company)
100 parts by weight of 1), and 80 parts by weight of hexahydrophthalic anhydride.
A homogeneous mixture consisting of 0.5 parts by weight of tetra-n-butylphosphonium benzosulfimizo, - 80°C
, for 2 hours, and then heated at 130°C for 3 hours, resulting in a cured product with a heat distortion temperature of 134°C and a tensile strength of 493 Kf/c.
I1. Bending strength: 785 Kf/cd.

It showed a compressive strength of 1019 kg/-.

Example 5 Polyepoxy compound (DgR-33 manufactured by Dow Chemical Company)
100 parts by weight of 1), 80 parts by weight of hexahydrophthalic anhydride, and 0 parts by weight of tetraphenylphosphonium phthalimidate.
．． The cured product obtained by heating a homogeneous mixture of 5 parts by weight at 80°C for 2 hours and then at 130°C for 3 hours has a heat distortion temperature of 132°C, a tensile strength of 496 K9764, a bending strength of 776 Kf/cd, Compressive strength io z s K
f/ai't'' was shown.

Claims (1)

[Claims] 1. General formula (A) belonging to quaternary phosphonium salt: ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R_1, R_2, R_3 and R_4 are an alkyl group, an alkenyl group, an aryl group) , represents a benzyl group, and R_5 represents a hydrogen atom or a methyl group.) General formula (b): ▲ There are numerical formulas, chemical formulas, tables, etc. ▼ (R_1, R_2 in the formula , R_3 and R_4 represent an alkyl group, an alkenyl group, an aryl group, a benzyl group.) General formula (c): ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula R_1, R_2, R_3, and R_4 represent an alkyl group, an alkenyl group, an aryl group, and a benzyl group.) A phosphonium phthalimidate compound represented by the above general formulas (a), (b), and (c); An epoxy resin curing agent containing one or more compounds selected from the following as an active ingredient.