JPS6037103B2 - Production method of unsaturated organic acid glycidyl ester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an unsaturated organic acid glycidyl ester, and more particularly to a method for preventing polymerization during the production of an unsaturated organic acid glycidyl ester.

There is already a method for producing an unsaturated organic acid glycidyl ester by reacting an unsaturated organic acid with excess epichlorohydrin in the presence of a catalyst, and then removing water by co-dehydration in the presence of an alkali. Known (Special Publication No. 37-745
No. 4). The disadvantage of this method is that polymerization tends to occur during the reaction. When polymerization occurs, not only does the yield of the unsaturated organic acid 1J sidyl ester decrease, but it may also become difficult to remove the reactant from the reaction vessel. Adding a polymerization inhibitor may be considered as a method of preventing this polymerization, but it is difficult to completely prevent polymerization.
As a result of extensive research, the present inventors have completed the present invention.

That is, when obtaining an unsaturated organic acid chlorohydrin ester by reacting an unsaturated organic acid with an excess of epichlorohydrin, the 'a-unsaturated organic acid is reacted almost quantitatively to reduce the residual rate to 3%. [b] A method in which air is blown into the reaction solution as described below, and then an unsaturated organic acid glycidyl ester is obtained by azeotropic dehydration with epichlorohydrin in the presence of an alkali. By this method, unsaturated organic acid glycidyl esters can be obtained in high yields without polymerization occurring during the reaction.

Examples of unsaturated organic acids include acrylic acid, methacrylic acid, crotonic acid, and incrotonic acid.

The amount of epichlorohydrin used is 2 to 1 mole of unsaturated organic acid. As a reaction catalyst between an unsaturated organic acid and epichlorohydrin, quaternary ammonium salts such as trimethylbenzylammonium chloride, triethylbenzylammonium chloride, and triethylmethylammonium chloride are preferable, and the amount added is equal to the amount of the unsaturated organic acid. 0 for
．． 01 to 5 mol% is suitable. The reaction conditions for obtaining an unsaturated organic acid chlorohydrin ester from an unsaturated organic acid and epichlorohydrin are 60-1100○, 0.5-5
time is preferable. Caustic potash, caustic soda, and the like are used as the alkali, and they may be in solid form or in aqueous solution. The appropriate amount to be used is 1.0 to 1.3 times the mole of the unsaturated organic acid. Azeotropic dehydration is performed while adding alkali little by little.
The conditions are preferably 70 to 11,000, normal pressure or reduced pressure. A particularly important point at this time is to blow air into the reaction solution; if air is introduced above the surface of the reaction solution, intense polymerization will occur. The larger the amount of air blown, the better, but it must be controlled to the extent that epichlorohydrin does not escape. Next, the present invention will be explained with reference to Examples and Comparative Examples.

Example: Methacrylic acid 8.61k9 (100 mol), epichlorohydrin 92.5 kg (1000 mol), triethylbenzylammonium chloride 0.2k9 (0.9 mol)
After heating a mixture of 10 and hydroquinone monomethyl ether at 80 to 85 oO for 1 hour (residual rate of methacrylic acid 0.95%), while blowing air into the reaction solution at 80 oO per hour, the mixture was heated at 80 oO and 30 oHg. under reduced pressure of 48
% caustic soda aqueous solution 9.16k9 (110 mol) 2
The epichlorohydrin was added dropwise over a period of time, and water was separated from the epichlorohydrin distilled out by azeotropy, and only the epichlorohydrin was returned to the reaction system.

After filtering out the raw salt, it was distilled to obtain glycidyl methacrylate 13.2k9 (yield 93%). In addition,
No generation of polymers was observed during the reaction. Comparative example 1~
8 The same procedure as in Example was carried out except that the method and amount of air blowing were changed.

However, the reaction time between methacrylic acid and epichlorohydrin in Comparative Examples 5 to 8 was 5 times. The results are shown in Table 1.
When air is blown onto the reaction liquid surface during azeotropic dehydration, when air is blown into both the reaction liquid surface and into the reaction liquid, and when no air is blown, polymers are generated. ,
The yield of glycidyl methacrylate is also low. Further, when the residual rate of methacrylic acid is high, even if air is blown only into the reaction solution, a large amount of polymer product is generated.・Table 1

Claims (1)

[Claims] 1. A method for producing an unsaturated organic acid chlorohydrin ester from an unsaturated organic acid and excess epichlorohydrin, and then producing an unsaturated organic acid glycidyl ester by azeotropic dehydration with epichlorohydrin in the presence of an alkali. In,
An unsaturated organic acid characterized in that (a) the unsaturated organic acid is reacted almost quantitatively so that the residual rate is 3% or less, and (b) air is blown into the reaction liquid during the azeotropic dehydration reaction. Method for producing glycidyl ester. 2. The method for producing an unsaturated organic acid glycidyl ester according to claim 1, wherein the unsaturated organic acid is acrylic acid, methacrylic acid, crotonic acid or incrotonic acid.