KR880002090B1 - Process for the preparation of vinyl ester resin - Google Patents

Abstract

A vinyl ester resin is prepd. by reacting an unsaturated monovalent basic acid e.g. acrylic acid or methacrylic acid with a compd. of epoxy in the presence of a reactive catalyst compd. of formula (I) and a polymerization inhibitor. In (I), R1 is H or methyl; R2 and R3 are methyl or ethyl. The catalyst compd. is selected from N, N- dimethylamino ethylacrylate, N,N-dimethylamino ethyl methacrylate, N,N-diethylamino ethylacrylate or N,N-diethylamino ethyl methacrylate.

Description

Method for producing vinyl ester resin

The present invention relates to a method for producing a vinyl ester resin which is diluted as a copolymerizable vinyl monomer by reacting an unsaturated monobasic acid and an epoxy compound in the presence of a new catalyst and a polymerization inhibitor.

Since vinyl ester resins have similar hardening and operating methods to unsaturated polyester resins, their workability is extremely good and their fields of application are as extensive as corrosion resistant reinforced plastics, linings, adhesives, and molds. Due to its good physical properties, it is expected to be an ultraviolet or electronic curing paint.

Conventionally, many catalysts have been used for addition reactions of unsaturated monobasic acids and epoxy compounds, but have many defects.

For example, in N, N-dimethyl aniline catalysts, the catalyst activity is good but there is a risk of rapid gelation at the end of the reaction, the reaction product is colored brownish brown, and in the quaternary ammonium chloride catalyst alkylenechlorohydrin produced as a side reaction This product has a drawback of incorporating into the product and deteriorating physical properties.

In addition, tertiary amines and dithiol salts have a weak catalytic activity. In the case of N, N-dimethylacetamide catalysts, the storage properties are good, but the catalytic activity is weak, so that the reaction time is long and the reaction product is colored.

The present invention uses a catalyst having moderate catalytic activity, low coloration of the reaction product, participating in curing during final curing, and no side reactions.

(다만, R₁은 수소 또는 메틸기, R₂및 R₃는 메틸기 또는 에틸기)로 표시된다.In the present invention, the catalyst used is a general formula

(However, R ₁ is hydrogen or a methyl group, R ₂ and R ₃ is a methyl group or an ethyl group).

Examples of the compound represented by the general formula include NN-dimethylamino ethyl acrylate, NN-diethylamino, ethyl acrylate, NN-dimethylamino ethyl methacrylate, NN-diethylamino ethyl methacrylate, and the like. have. These compounds use 0.01-5% (weight ratio), suitably 0.1-1.0% (weight ratio) relative to the mixture of unsaturated monobasic acid and epoxy compound.

Reaction of unsaturated monobasic acid and an epoxy compound generally follows a well-known method. That is, the carboxyl group in unsaturated monobasic acid was added at a ratio of about 0.5-1.5 moles to 1 mole of epoxy groups contained in the epoxy compound to three flasks, and an appropriate amount of a polymerization inhibitor and a reaction catalyst were added. It reacts until it becomes below. In general, the reaction time is 3-10 hours, the reaction is preferably carried out under air or nitrogen stream. Upon completion of the reaction, the mixture was cooled to 50-70 ° C. and diluted to 50-90% solids with a copolymerizable vinyl monomer.

Examples of the unsaturated monobasic acid used in the present invention include acrylic acid and methacrylic acid, and a part thereof may be replaced with saturated monobasic acid, saturated dibasic acid or unsaturated dibasic acid to improve curability and workability.

These compounds include benzoic acid, phthalic anhydride, adipic acid, isophthalic acid, maleic anhydride, fumaric acid, and the like. As the epoxy compound, for example, a reaction between diglycidyl etherphenol and formaldehyde, produced by reaction of 2.2-bis (4-hydroxyphenyl) propane with epichlorohydrin or methyl epichlorohydrin Compounds containing two or more epoxy groups such as polyglycidyl ether prepared by the reaction of novolak and epichlorohydrin or methyl epichlorohydrin obtained by the compound or one epoxy group for improving curability and workability You may use together the compound containing, ie, ethylene oxide, a phthalene oxide, epiglorohydrin, a glycidyl methacrylate, etc.

The epoxy equivalent of the said compound is about 2000 or less, and the suitable thing is 100-1000, It is possible to use together 1 type (s) or 2 or more types.

In addition, examples of the copolymer synthetic vinyl monomers include styrene, acrylic acid and esters thereof, methacrylic acid and esters thereof, and vinyl toluene. In addition, polymerization inhibitors were hydroquinone monomethyl ether, t-butylcatechol, benzoquinone, and the like.These compounds were 0.01-1.0% (by weight) and preferably 0.05-0.5% (by weight) relative to unsaturated monobasic acids. use. The compound of the present invention has a strong catalytic action when etherifying an epoxy group in an epoxy compound with a carboxyl group of an unsaturated monobasic acid, but there is no fear of gelation during the reaction. Therefore, the reaction product is low viscosity, low acid value, light color, transparent and has good curability and storage stability.

The vinyl ester resin, which is a reaction product obtained using the compound of the present invention, is cured at high temperature using a suitable curing agent such as benzoyl peroxide, 1-butyl peroxide, cumene hydroperoxide, t-butylperbenzoate, or the like. It is possible to cure at room temperature using cobalt naphtanate-methylethyl ketone peroxide and dimethylaniline-benzoyl peroxide. An Example is given to the following and this invention is concretely demonstrated to it.

Example 1

388 parts of epoxy resin KE-828 (manufactured by Construction Chemical Co., Ltd., epoxy equivalent 194), 90 parts of methacrylic acid, 0.1 part of hydroquinone, 3 parts of NN-dimethyl amino ethyl methacrylate under an air stream in a 1 liter three-neck flask. It reacted at 120 degreeC for 3 hours.

At this time, the acid value was 7.0. The reaction product was not gelated even after reacting for another 7 hours.

Example 2

126 parts of epoxy resin KE-828 (product of Construction Chemical Co., Ltd., epoxy equivalent 194), 320 parts of epoxy resin KE-1001 (product of Construction Chemical Co., Ltd., epoxy equivalent 492), 100 parts of acrylic acid, 0.2 parts of t-butycatechol 2.5 parts of NN-dimethylamino ethylacrylate was reacted for 4 hours at 110 degreeC under nitrogen stream in a 1 liter three neck flask.

At this time, the acid value was 9.4. The reaction product was cooled to 70 ° C. and diluted with 440 parts of styrene monomer.

The vinyl ester resin thus prepared had a viscosity (25 ° C.) of 1.65 poise, an acid value of 5.1 colors (Gardner color number), and transparency.

When 1 part of 5% cobalt naphthanate and 1 part of methyl ethyl ketone peroxide were added to 100 parts of this resin liquid, it was gelation time 25 minutes and hardening time 40 minutes.

Example 3

It reacted at 110 degreeC for 4 hours similarly to Example 2 except having used N.N- diethyl amino ethyl methacrylate instead of N.N- dimethylamino ethyl acrylate in Example 2. At this time, the acid value was 9.0. The reaction product was cooled to 70 ° C. and diluted with 440 parts of styrene monomer. The vinyl ester resin thus prepared had a viscosity (25 ° C.) 1.66 poise acid value 5.0 color (Gardner color number) 1 and good transparency.

When 1 part of 5% cobalt naphthanate and 1 part of methine ethyl ketone peroxide were added to 100 parts of this resin liquid, it was gelation time 25 minutes and curing time 38 minutes.

Comparative Example 1

The reaction was carried out at 120 ° C. for 3 hours in the same manner as in Example 1 except that N.N-dimethylaniline was used instead of N.N-dimethylamino ethyl methacrylate in Example 1. At this time, the acid value was 7.5. The reaction product gelled when reacted for another 2 hours.

Comparative Example 2

The reaction was carried out at 110 ° C. for 4 hours in the same manner as in Example 2 except that N.N-dimethylacetamide was used instead of N.N-dimethylaminoethyl acrylate in Example 2.

At this time, the acid value was 24.5 and after 3 hours, the acid value was 13.1.

The reaction product was cooled to 70 ° C. and diluted with 440 parts of styrene monomer.

The vinyl ester resin thus prepared had a viscosity (25 ° C.) 1.45 poise acid value 7.2 color (Gardner color number) 3 and good transparency.

When 1 part of 5% cobalt naphthanate and 1 part of methyl ethyl ketone peroxide were added to 100 parts of this resin liquid, the gelation time was 30 minutes and the curing time was 50 minutes.

Comparative Example 3

In Comparative Example 2, the reaction was carried out at 110 ° C. for 4 hours in the same manner as in Example 2, except that triethylamine was used instead of N.N-dimethylamino ethyl acrylate.

The acid value was 25.1 and the acid value became 14.5 after 3 hours of further reaction.

The reaction product was cooled to 70 ° C. and diluted with 440 parts of styrene monomer.

The vinyl ester resin thus prepared had a viscosity (25 ° C.) 1.40 poise acid value 8.0, color (Gardner color number) 4 and poor transparency.

When 100 parts of this resin solution was added with 5% cobalt naphthanate and 1 part of methine ethyl ketone peroxide, the gelation time was 15 minutes and the curing time was 50 minutes.

[Reference Example]

Table 1 shows the results of the storage stability promotion test of the vinyl ester resins prepared in Examples and Comparative Examples at 60 ° C.

TABLE 1

Claims (3)

General formula for reacting unsaturated monobasic acid and epoxy compound in the presence of polymerization inhibitor

(However, R ₁ is hydrogen or a methyl group, R ₂ , R ₃ is a methyl group or an ethyl group) using a compound represented by the reaction catalyst, the production method of a vinyl ester resin. The method of claim 1, wherein the compound represented by the general formula uses at least one selected from N.N-dimethylamino ethylacrylate, N.N-dimethylamino methacrylate, and N.N-diethylamino ethyl methacrylate. The process of claim 1 wherein the reaction catalyst is 0.01-5% (weight ratio) relative to unsaturated monobasic acids and epoxidation.