Process for the preparation of methacrylic acid esters.

摘要

A process for preparing a methacrylic acid ester by reacting methacrylic acid with a lower aliphatic alcohol in the liquid phase using a solid acid catalyst at a molar ratio of alcohol to methacrylic acid to 1.2-3.0 and a reaction temperature of 70°-100°C is improved by
<UnorderedLists id="ula01" listStyle="none"><ListItem>1) extracting the unreacted alcohol from the reaction mixture with an aqueous solvent at a temperature of 25° to 70°C,</ListItem><ListItem>2) removing the low boiling substances from the extraction residual mixture by distillation, whereby an organic residue is generated containing methacrylic acid ester and unreacted methacrylic acid, and</ListItem><ListItem>3) separating the unreacted methacrylic acid and the methacrylic acid ester by distillation.</ListItem></UnorderedLists>

The preferred alcohol is methyl, ethyl or isopropyl and the preferred catalyst is a sulfonic acid type cation exchange resin.