JPS59109508A - Low-odor resin composition - Google Patents

Abstract

PURPOSE:To low-odor unsaturated polyester resin composition, prepared by using a dimethyl ester of a dimerized methacrylic acid as a crosslinking monomer component. CONSTITUTION:An unsaturated polyester resin body (e.g., ''Yupika 8542'', a product of Nippon Yupika Co., Ltd.) is mixed with a dimethyl ester of dimerized methacrylic acid of the formula, and about 0.5-10wt%, based on the resin composition, curing agent, preferably, an organic peroxide whose 10hr half-life decomposition temperature is above 90 deg.C, e.g., t-butyl perbenzoate.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a low odor unsaturated polyester resin composition.

Traditionally, unsaturated polyester resins have poor mechanical properties.

It has been used in large quantities in fields such as fiber-reinforced plastics, paints, adhesives, and electrical parts due to its electrical properties, heat resistance, workability, and low cost.

The unsaturated polyester resin mainly consists of a body and a crosslinkable monomer, and generally contains 20 to 60% by weight of the crosslinkable monomer. Conventionally, most of the crosslinking monomers used from the viewpoint of properties or economy are styrene.

This styrene is easy to volatilize, and when it hardens, it
40! The chlorine evaporates and produces a pungent odor, which gives off an unpleasant odor to workers and local residents, posing a health management problem that has led to legislation being put in place.

In view of the above circumstances, the present inventors conducted intensive studies on low-odor crosslinking monomers that could replace styrene, and as a result, discovered a new resin that could replace conventional vinyl resins.

The present invention comprises (1) an unsaturated polyester resin body, (2)
) methacrylic acid dimer dimethyl ester; and (3) a curing agent.

The unsaturated polyester resin body used in carrying out the present invention is a commonly used body, which is prepared by condensation reaction with an industrially produced alcohol component, acid component, and optionally a modifier. It is obtained by
It is not particularly limited.

Methacrylic acid dimer dimethyl ester, which is the second component of the present invention, is a by-product during the synthesis of methyl methacrylate, and has the chemical structure shown in the following formula.

CH.

This methacrylic acid dimer dimethyl ester has a high boiling point of 235° C. at normal pressure, and is a crosslinkable monomer that is almost odorless.

The curing agent, which is the third component of the present invention, is an organic peroxide, such as asyl oxide such as benzoyl peroxide or acetyl peroxide, or tert-butyl peroxide.

Hydroperoxides such as cumene hydroxy peroxide, ketone peroxides such as methyl ethyl ketone peroxide, cyclohexano/peroxide, dialkyl peroxides such as ditertiary butyl per7oxide, dicumyl peroxide, tertiary butyl perbenzoate, tertiary butyl peroxide, etc. It is desirable to use oxyperoxide such as butyl peroxyacetate.

Since the methacrylic acid dimer dimethyl ester has slightly lower homopolymerizability and copolymerizability than other vinyl monomers, the decomposition temperature for obtaining a half-life of 10 hours is particularly high among the organic peroxides. A temperature of 90° C. or higher is preferable, and the time required for complete curing is shortened.

The amount of the curing agent added to the resin composition is generally 0.
It ranges from 5 to 10 parts by weight, preferably from 1 to 5 parts by weight.

The resin composition of the present invention contains polyfunctional (meth)acrylates for the purpose of improving heat resistance, thermoplastic resins for low shrinkage such as saturated polyester resins, acrylic resins, vinyl resins, etc., and fillers such as silica. ,talc,
Calcium carbonate, asbestos, glass fiber, wood flour, coloring agents, etc. can be added as necessary.

Next, the present invention will be explained with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Example 1 Isophthalic acid-based unsaturated polyester resin, Yubika ■85
42 (manufactured by Nippon Yubika KK, unsaturated polyester resin body) 100F, methacrylic acid dimer dimethyl ester 3
57' and tert-butyl perbenzoate 5P were mixed to obtain a resin composition.

Comparative Example 1 A resin composition was obtained in the same manner as in Example 1, except that styrene was used instead of methacrylic acid 2-1 it dimethyl ester.

The resin compositions obtained in Example 1 and Comparative Example 1 were poured into a glass molder and heated at 140° C. for 4 hours. The glass transition temperature of the test piece cut from this cast material was 9
Table 1 shows the measurement results of bending strength 2, bending modulus, elongation, and volatility of the resin composition before curing.

As can be seen from the above results, the resin composition of the present invention has a slightly inferior glass transition temperature 1 bending strength and bending elastic modulus of the cured product compared to unsaturated polyester resin using styrene, but has a large elongation. It also has an extremely low volatile content and low odor even when cured.

Table-1 *Resin composition 10 on 60φ metal shear plate! and 5
The superposition change after heating at 0° C. for 4 hours was determined.

Example 2 = Vika ■ 8542 □oot 12,7 phosphoric acid dimer dimethic acid dimer 15 parts of dimethyl estrimethylol propane trimethacrylate and 6 parts of tertiary butyl perpe/shade were mixed and stirred to form a resin composition. Obtained. Next, the composition was cured by heating at 140°C for 4 hours, and a cured product with a glass transition temperature of 130°C was obtained. This cured product has very few volatile components as in Example 1,
Almost no odor was generated even during curing.

Claims (1)

[Claims] 1. (IJ unsaturated polyester resin body, (2j
A low-odor resin composition comprising dimethyl ester of methacrylic acid 2 and (3) a curing agent. 2. The decomposition temperature for the curing agent to obtain a half-life of 10 hours is 9
Claim 1, which is an organic peroxide having a temperature of 0°C or higher
The resin composition described in .