JPS61148228A - One pack-type epoxy resin composition - Google Patents

Abstract

PURPOSE:To provide the titled composition having excellent rapid curability at a low temperature, stability at normal temperature, and storage stability, and giving a cured product having excellent transparency, by compounding an epoxy resin with a specific OH-containing compound and a specific latent hardener. CONSTITUTION:The objective composition can be produced by compounding (A) 100pts.(wt.) of an epoxy resin (e.g. bisphenol a glycidyl ether) with (B) preferably 5-50pts. of a compound having >=2 hydroxyl groups (e.g. bisphenol A) and (C) preferably 0.5-40pts. of a latent hardener obtained by reacting (i) a polyfunctional epoxy compound with (ii) a compound having a tert-amino group and one or more OH group, SH group, COOH group or CONHNH2 group, or reacting the components (i) and (ii) with (iii) an organic compound having >=2 active hydrogen atoms.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application: The present invention relates to a one-component epoxy resin composition. Specifically, it has low-temperature fast curing properties,
The present invention also relates to an epoxy resin composition that provides a good cured product and has excellent stability at room temperature.

Problems that conventional techniques and inventions attempt to solve...
...One-component epoxy resins are more desirable than conventional two-component ones for reasons such as prevention of blending errors, continuous production, and production line production. - Liquid epoxy resin does not react with epoxy compounds at room temperature, but
A so-called latent curing agent is required, which reacts and hardens when heated. As a latent curing agent, dicyandiamide,
Dibasic acid dihydrazides are well known, and although epoxy resin compositions containing these are stable at room temperature, they have the disadvantage of requiring heating at considerably high temperatures and for long periods of time during curing.

Means for solving the problem (part 1)...The present inventors have previously developed (a) a polyfunctional epoxy compound, (b)
) OI-T group, SH group, COOH group and CO
(a) and (b) or (c) an organic compound having at least one functional group of NHNH2 groups and a tertiary amino group; It was proposed that an addition compound obtained by reacting (a), (b), and (c) would be a latent curing agent with excellent low-temperature, rapid curing properties and storage stability, but it also has a faster curing speed. As a result of studying liquid epoxy citrus resin, which has excellent physical properties of cured products, it was found that by combining the above-mentioned addition compounds with polyhydric alcohols and polyhydric phenol compounds, the curing speed was increased; It was discovered that it was possible to obtain an excellent cured product with good transparency, which had been difficult, and the present invention was completed.

That is, the present invention provides (1) an epoxy resin, (2) a compound having two or more hydroxyl groups in the molecule, (3) (a) a polyfunctional epoxy compound, and (b) an OI (group, SH group, COOI group) in the molecule. (Group and CON HN H
(a) and (b) or (c) a compound having at least one of the two functional groups and a tertiary amino group and (c) an organic compound having two or more active hydrogens in the molecule; (
The present invention relates to a liquid epoxy resin silk composition containing a latent curing agent for epoxy resin which is an 1-addition compound obtained by reacting a), (b), and (c).

Effects of the invention: As curing agents for epoxy resins, phenolic compounds and alcohol compounds do not react with epoxy resins without catalyst unless at high temperatures.For example, imidazole is used for the reaction between solid epoxy resins and phenol novolac Although compounds are known to be effective as catalysts, the use of such catalysts has the drawback of impairing the storage stability of the composition. The latent curing agent, component (3) of the present invention, enables rapid curing at low temperatures without impairing storage stability. That is, the one-component epoxy resin composition of the present invention is characterized by excellent storage stability, particularly rapid curing properties, and good physical properties of the cured product. In addition, this formulation makes it possible to form alicyclic epoxy resin into a single component, which has been difficult in the past. 1 Means for solving the problem (part 2)...3 Epoxy resins that can be used in the present invention (1) have two or more epoxy groups in the molecule, such as bisphenol A1 Polyglycidyl ethers obtained by reacting polyhydric phenols such as bisphenol F, polyhydric alcohols such as glycerin, and epichlorohydrin, polyglycidyl esters obtained from polycarboxylic acids, epoxidized novolaks, and even 3,4.-epoxy. -6-methylcyclohexylmethyl-3,4,-epoxy-6-
Examples include alicyclic epoxy resins such as methyl cyclohexane carboxylate.

(2) Compounds having two or more hydroxyl groups in the molecule are:
All so-called polyhydric alcohols and polyhydric phenols can be used, but in order to particularly improve the storage stability of the epoxy resin composition, compounds with a melting point of 80° C. or higher are desirable. Examples of such compounds include polyhydric phenols such as bisphenol A, bisphenol F, bisphenol S, hydroquinone, resorcinol, and phenol novolac resin, neopentyl glycol 4-ol, glycerin, trimethylolethane, trimethylolpropane, Examples include polyhydric alcohols such as pentaerythritol, dipentaerythritol, and D-sorbitol, and the blending amount thereof is preferably 5 to 50 parts by weight based on 100 parts by weight of the epoxy resin.

The amount of the latent curing agent (3) is preferably 0.5 to 40 parts by weight per 100 parts by weight of the epoxy resin.

In the present invention, there are no particular restrictions on the method of mixing the above components (1) to (3). For example, the method of mixing the components (1) to (3) above is not particularly limited. It may be dissolved.

Further, other curing agents and fillers may be added to the one-component epoxy resin composition of the present invention, if necessary.

Examples: Next, the usefulness of the present invention will be specifically explained using examples.

The abbreviations of raw materials used in the examples are as follows.

(1) Epoxy resin “Epicort 828J (Shell Chemical @) Bisphenol A-based epoxy resin Epoxy equivalent It 185-190 “Epicor” 807J (Shell Chemical ■) Bisphenol-F-based epoxy resin Epoxy equivalent 166-175 “Celoxide 2021J (Daicel Chemical Industries) I
41) Alicyclic epoxy resin Epoxy equivalent: 133 to 135 Further, as the latent curing agent of (3), curing agents A and B were synthesized as follows.

Synthesis Example 1 Synthesis of Curing Agent A 0.6 g (0.05 g of 1-(2-hydroxy-=3-butoxypropyl)-2-methylimidazole I
equivalent), bisphenol A5.7 g (0.05 equivalent I
IL), 50 ml of methyl ethyl ketone was added as a solvent, and 19 g (0.1 equivalent) of Epicote 828 J dissolved in 30 ml of methyl ethyl ketone was added dropwise (30 minutes) while heating and stirring. After the dropwise addition, the mixture was stirred for 2 hours. The mixture was heated to reflux. The solvent methyl ethyl ketone was distilled off under reduced pressure, and upon cooling, a pale yellow solid adduct was obtained. This solid was pulverized to obtain a curing agent A.

Synthesis Example 2 Synthesis of Curing Agent B 33.4 g (0,176 equivalent Jl) of Epicote 828 J and 26-5 g (o, + equivalent) of 2,4,6.-tris(dimethylaminomethyl)phenol were placed in a beaker. Weigh it out, mix well at room temperature, and gradually raise the temperature while stirring.The reaction proceeds rapidly at around 70°C and is kept at 100°C for about 1 hour.After the reaction is complete, when cooled, a light yellow color appears. A solid was obtained, which was pulverized to obtain hardening agent B.

Example 1 The products were prepared and evaluated for curability and storage stability.

1. Evaluation of curability (1-1) Curing initiation temperature and peak temperature were measured by differential thermal analysis.

Sample: Approximately 10 mg Reference substance α-alumina Heating rate: 5°C/min (1-2) A sample was placed in a gear oven at a constant temperature and its hardening state was observed.

2. Storage stability A sample was placed in a constant temperature bath at a predetermined temperature (30°C), and the number of days until fluidity disappeared was measured.

3. Glass transition temperature (Tg) The Tg of a sample cured at a predetermined temperature and time was measured by the TMA penetration method using a thermomechanical analyzer (TMA, manufactured by Rigaku Denki ■).

Heating rate: 10℃/min Load Weight 10g 81 Example 2 -1〇= Table 2 Table 3 -I3-

Claims (3)

[Claims] (1) Epoxy resin (2) Compounds with two or more hydroxyl groups in the molecule (3) (a) Polyfunctional epoxy compound, (b) OH group, SH group, COOH group and CON in the molecule
(a) and (b) or (a) of a compound having at least one functional group of the HNH2 group and a tertiary amino group; and (c) an organic compound having two or more active hydrogens in the molecule. ) and (b) and (c
) A one-component epoxy resin composition containing a latent curing agent for epoxy resin consisting of an addition compound obtained by reacting with