Process for producing carboxylic acid esters and catalysts therefor

摘要

A process for producing carboxylic acid esters by the following steps: a) preparation of a reaction mixture containing an alcohol and a carboxylic acid and/or a carboxylic anhydride and/or a carboxylic acid ester and or a partially esterified carboxylic acid, b) heating of this mixture to the suitable reaction temperature in the presence of a solid polysiloxane insoluble in the reaction medium and having sulphonic acid groups with intensive thorough mixing accompanied by continuous separation of the reaction water which forms, wherein the polysiloxane used as the catalyst in modified by treatment with a soluble aluminum, titanium or zirconium compound, and the spherical particles thereof have a diameter of 0.01 to 3 mm, a specific surface of 0.1 to 1200 m2/g, a specific pore volume of 0.01 to 6.0 ml/g and a bulk density of 50 to 1000 g/l.