JPH0363966B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an epoxy resin curing agent containing quaternary ammonium triazolate as an active ingredient. The triazolate is obtained by intermolecular dehydrohalogenation of a quaternary ammonium halide and a triazole compound, that is, the detailed reaction is shown in the formula
It is synthesized according to the reaction shown in (1). [In the formula, R ₁ , R ₂ , R ₃ and R ₄ independently represent a saturated or unsaturated alkyl group having 1 to 22 carbon atoms or a benzyl group, and R ₅ represents a hydrogen atom or a methyl group. ] The quaternary ammonium halide, which is a raw material for the above reaction, is generally produced and used widely as a cationic surfactant, and the other reaction raw material, a triazole compound, is prepared by combining o-phenylenediamine and nitrous acid. It is easily synthesized. This substance is an industrial chemical that is used in large quantities as a rust preventive agent for nonferrous metals. The present inventors were interested in the reaction between a quaternary ammonium compound and a triazole compound, and as a result of extensive research, they arrived at the present invention. The quaternary ammonium triazolate according to the present invention is unique in that it has an ammonium cation as the cation component and a triazole anion instead of the halogen ion of the strong electrolyte as the anion component, unlike the quaternary ammonium compound in the general concept. It is something that has properties. The characteristics of the triazole will be described below. 1 Compared to general quaternary ammonium halides, it is less soluble in water and extremely soluble in organic solvents. 2 Decomposes with acid and separates into its constituent quaternary ammonium compounds and triazole. 3 Stable to water and heat. By utilizing the above properties, we have found that the triazole compound can be used as an epoxy resin curing agent. It is a well-known fact that the quaternary ammonium halide, which is the raw material for the triazolate, acts as an epoxy curing agent; however, this quaternary ammonium halide has a hydrophilic halogen ion as an anion component. It has poor compatibility with epoxy resins, and has the disadvantage that halogen ions, which are strong electrolytes, are incorporated into the cured resin, which significantly impairs the electrical insulation properties of the cured resin. In addition, quaternary ammonium halide, which is composed of a strongly basic quaternary ammonium cation and a strongly acidic halide ion, is a neutral salt and has extremely poor activity as an epoxy curing agent, resulting in a prolonged pot life. Even if it is good, it has the drawback of reduced curing properties when heated. However, since the anion component of the triazole compound is a lipophilic triazole ion, it has good compatibility with the epoxy resin, and because it is a weak electrolyte ion, the electrical insulation properties of the cured resin are not impaired. In addition, since this compound is a salt of a strongly basic quaternary ammonium cation and a weak acid triazole ion, it is more active as an epoxy curing agent than the neutral salt quaternary ammonium halide, and has a shorter pot life. It has the characteristic that the heat curing property does not decrease even if it is significantly extended. Note that the present invention includes cases in which the quaternary ammonium triazole compound is used alone as a curing agent and in combination with other curing agent components. The polyepoxy compound in the present invention contains more than one epoxy group per molecule on average, and this group is located at the terminal position of the molecule.

[Formula] is also acceptable, or in the middle of the molecular formula intervened in

A group of the form [Formula] may be formed. The polyepoxy compound may be aliphatic, cycloaliphatic, aromatic, or heterocyclic, and may include hydroxyl, alkyl, alkoxy,
It may be substituted with non-interfering substituents such as ester groups, acetal groups, and ether groups. The most preferred polyepoxy compounds are polyglycidyl ethers of polyhydric phenols such as bisphenol A, bisphenol F, resorcinol hydroquinone, 4,4'-diphenol, hydroxydiphenyl sulfone, phenol formaldehyde resin, and cresolate formaldehyde resin. be. Examples of other suitable polyepoxy compounds include glycidyl ethers of polyhydric alcohols such as ethylene glycol, propylene glycol, glycerin, trimethylolpropane, 1,4-butanediol, phthalic acid, tetrahydrophthalic acid, and hexahydrophthalic acid. , polyglycidyl esters of polyhydric carboxylic acids such as adipic acid and dimer acid, glycidyl amines, epoxidized polyolefins, and epoxidized vegetable oils. Further, specific examples of the quaternary ammonium triazole which is the most characteristic epoxy resin curing agent in the present invention include trimethyloctylammonium benzotriazolate, trimethyldodecylammonium benzotriazolate, and trimethylhexadecyl. Ammonium tolyl triazolate, trimethyloctadecyl ammonium benzotriazolate, trimethylbehenylammonium tolyl triazolate, trimethylbenzylammonium benzotriazolate, dimethyldioctyl ammonium tolyl triazolate, dimethyldodecylbenzylammonium tolyl triazolate, dimethyltetradecyl Benzyl ammonium benzotriazolate, dimethylhexadecyl benzyl ammonium tolyl triazolate, dimethyl octadecyl benzyl ammonium benzo triazolate, dimethyl oleyl benzylammonium benzo triazolate, dimethyl behenyl benzyl ammonium benzotriazolate, dimethyl dibenzy ammonium tolyl triazolate azolate, tribenzylmethylammonium benzotriazolate, didodecylbenzylmethylammonium tolyltriazolate, trioctylmethylammonium benzotriazolate, trioctylbenzylammonium benzotriazolate, tetraoctylammonium benzotriazolate, etc. . The curable composition of the present invention may contain a plasticizer such as dibutyl phthalate or dioctyl phthalate, an inert organic solvent or a so-called reactive diluent,
In particular, it may contain monoepoxides such as butyl glycidyl ether phenyl glycidyl ether. In addition, the composition obtained according to the present invention may be added with various additives such as extenders, fillers, and reinforcing agents at any stage prior to curing, such as pigments, dyes, flame retardants, thixotropic agents, flow inhibitors, and sagging agents. A polymer substance or the like as a sex imparting agent may also be included. Hereinafter, embodiments of the present invention will be explained by way of examples. Example 1 Polyepoxy compound (manufactured by Ciel Chemical Co., Ltd.,
5 parts by weight of the curing agent of the present invention were added to 100 parts by weight (trade name: Epicote 828) and mixed and dissolved at room temperature. This was heated at 80°C for 2 hours and then at 130°C for 4 hours. The 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 that was cured in the same manner as above using dimethyltetradecylbenzylammonium chloride instead of the curing agent of the present invention.

[Table] Example 2 A homogeneous mixture of 100 parts by weight of a polyepoxy compound (trade name Epicote 828, manufactured by Ciel Chemical Co., Ltd.) and 10 parts by weight of a curing agent is prepared. Table 2 shows the gelation time of this composition at 120°C, the pot life at 40°C, and the pot life gelation time ratio determined therefrom.

【table】

[Table] What is the gelation time in the table above? Place about 0.5g of the composition on a hot plate maintained at 120±0.5℃, and spread the composition ^{by 2} to 3cm3 with a metal spatula, making one round trip every 2 seconds. This refers to the time it takes until no threads leak between the composition and the spatula when the composition is kneaded while being pressed uniformly and the spatula is lifted. Pot life is a process in which the composition is stored at a temperature of 40°C and the change in viscosity is measured.
This is the time it takes to reach 10 times. Further, the pot life gelling time is the ratio of the gelling time to the pot life value.

Claims (1)

[Claims] 1 General formula [Formula] [Formula] [In the formula, R ₁ , R ₂ , R ₃ , and R ₄ each independently represent a saturated or unsaturated alkyl group having 1 to 22 carbon atoms or a benzyl group. R ₅ represents a hydrogen atom or a methyl group. ] An epoxy resin curing agent containing a quaternary ammonium triazole compound represented by the following as an active ingredient.