JPS61171722A - One-pack epoxy resin composition - Google Patents

Abstract

PURPOSE:To provide the titled composition of low-temperature rapid curability, good in stability at room temperature and storage stability, capable of giving high-quality cured products, comprising alicyclic epoxy resin, polybasic acid hydrazide compound and specific potential curing agent for epoxy resin. CONSTITUTION:The objective composition comprising (A) an alicyclic epoxy resin (e.g., 3,4-epoxycyclohexylmethyl-3,4-epoxy cyclohexane carboxylate), (B) a polybasic acid hydrozide compound (e.g., succinic acid dihydrazide) and (C) a potential curing agent consisting of addition reaction product from either (i) a polyfunctional epoxy compound and (ii) a second compound having both tertiary amino group and at least one functional group selected from OH, SH, COOH, and CONHNH2 groups or the components (i) and (ii) and (iii) an organic compound having at least two active hydrogens.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to one-component epoxy resin compositions.

Specifically, we will develop an epoxy resin composition that uses an alicyclic epoxy resin, has low-temperature rapid curing properties, provides a good cured product, and has excellent stability at room temperature.

[Prior art and problems to be solved by the invention] Among epoxy resins, alicyclic epoxy resins such as 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate have good weather resistance. known as. Furthermore, since it does not contain any chlorine impurity, which is often a problem with bisphenol-type glycidyl ether epoxy resins, it is ideal for sealing rings in electronic parts that dislike impurity ions. One-component epoxy resins have become more desirable than conventional two-component ones for reasons such as preventing mixing errors, making them continuous, and making it possible to create a production line. -Proposals have been made for liquid-based epoxy resins. However, liquid epoxy resins using the above-mentioned alicyclic epoxy resins are not yet known.

[Means for solving problems]

The present inventors previously prepared (a) a polyfunctional epoxy compound, (
b) OH group, SH group, COOH group and CONH group in the molecule
(a) and (b) or (c) a compound having at least one functional group of the NH2 group and a tertiary amino group; and (c) a tangential compound having two or more active hydrogens in the molecule. It was proposed that the addition compound obtained by reacting a), (b), and (c) would be a latent curing agent with low-temperature fast curing properties and storage stability, but as a result of further investigation, By combining the above addition compound and a polybasic acid hydrazide compound, it is now possible to form alicyclic epoxy resin into a single component, which was impossible until now.It has excellent curing properties at low temperatures and excellent transparency. They discovered that a product can be obtained and completed the present invention.

That is, the present invention provides (1) alicyclic epoxy resin (2) polybasic acid hydrazide compound (3) (a) polyfunctional epoxy compound, (b) OH group, SH group, COOH group, and CONHNH2 group in the molecule. and (c) an organic compound having two or more active hydrogens in the molecule, (a) and (b) or (a). (b
) and (c) are reacted to form a one-component epoxy resin composition containing a latent curing agent for epoxy resin, which is an addition compound obtained by reacting the following.

(1) Alicyclic epoxy resin that can be used in the present invention includes 3,4-epoxycyclohexylmethyl-3,4
- Epoxycyclohexane carboxylate (rERL-4221, manufactured by Union Carbide, USA), bis(3,4-epoxycyclohexylmethyl)adipate (rERL-4229, manufactured by Union Carbide, USA)
J), 2-(3,4-epoxycyclohexyl-5
,5-spiro-3,4-epoxy)cyclohexane-meta-dioxane (rERL manufactured by Union Carbide, USA)
-4234J), diisodecyl epoxy
Ji! , 1: Sahydrophthalate (“Recaresin E-
10J), etc.

It is also possible to use these alicyclic epoxy resins by heating them with other epoxy resins such as bisphenol A diglycidyl ether.

Examples of the polybasic acid hydrazide compound (2) include succinic acid dihydrazide, adipic acid dihydrazide, isophthalic acid dihydrazide, dodecanoic acid dihydrazide, eicosanoic acid dihydrazide, sepatic acid dihydrazide, etc., and the blending amount is 100% by weight of the above epoxy resin. 5 to 50 parts by weight is preferred.

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

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

〔Example〕

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

In addition, curing agent A is used as the latent curing agent in (3).

B was synthesized as follows.

Synthesis Example 1 Synthesis to Curing Agent 1-(2-hydroxy-3-butoxypropyl)-2-methylimidazole to 6 g (0,05
(equivalent), 5.7 g (0.05 eq.) of bisphenol A, and 50 ml of methyl ethyl ketone as a solvent were added.
19 g (0.1 equivalent) of "Ebicor" 828J dissolved in methyl ethyl ketone 301 was added dropwise (30 minutes) while causing heating loss. After the dropwise addition, the mixture was heated under reflux for 2 hours with stirring. Methyl ethyl ketone, the solvent, was added under reduced pressure. was distilled off and cooled to obtain a pale yellow solid adduct.This solid was pulverized to obtain curing agent A.

Synthesis Example 2 Synthesis of Curing Agent B "Epicote 828 J 33.4 g (0.1?6 eq. m> and 2.4,6.-) Lis(dimethylaminomethyl)phenol 26.5 g (0.1 eq.) Weigh the mixture into a beaker, 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, cool it down. A pale yellow solid was obtained, which was pulverized to obtain Curing Agent B.

EXAMPLE In order to demonstrate the usefulness of the present invention, formulations were prepared according to the proportions shown in Table 1, and their curability and storage stability were evaluated.

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, 7 minutes (1-2) The 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 (40°C), and the number of days until fluidity disappeared was measured.

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

Heating rate: 10℃/min Load Weight Log Needle diameter llll11 The results obtained are shown in Table 2.

The results of the comparative examples in Table 2 show that (1) alicyclic epoxy resin and (2) hydrazide compound alone do not cure at temperatures below 150°C, and that liquid acid anhydride is used instead of (2) hydrazide compound. It was found that the storage stability was poor in the case where the sample was mixed, and the effect of the present invention is clear.

i・ Table 2

Claims (3)

[Claims] (1) Alicyclic epoxy resin (2) Polybasic acid hydrazide compound (3) (a) Polyfunctional epoxy compound, (b) OH group, SH group, COOH group and CON in the molecule
(a) and (b) or (a) of compounds that have at least one functional group of HNH_2 groups and a tertiary amino group; and (c) organic compounds that have 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