PROCESS FOR PRODUCTION OF METHACRYLIC ACID ESTERS

摘要

A method for producing α-, β-unsaturated carboxylic acid esters in high yield from acetone cyanohydrin and sulfuric acid through the separation and concurrent catalytic conversion of reaction side products to additional α-, β-unsaturated carboxylic acid ester product. The catalyst comprises at least one Group IA element, and boron as a promoter, on a porous support.

主权项

1. A method for producing methacrylic acid esters comprising the steps of:
(d) providing a C1-C12 alkyl alcohol and an organic fraction comprising C1-C12 alkyl methacrylate, C1-C12 alkyl α-hydroxyisobutyrate and C1-C12 alkyl β-C1-C12 alkoxyisobutyrate; (e) vaporizing at least a portion of the organic fraction and at least a portion of the C1-C12 alkyl alcohol; (f) contacting the vaporized organic fraction and alcohol with a catalyst to convert the C1-C12 alkyl α-hydroxyisobutyrate and C1-C12 alkyl β-C1-C12 alkoxyisobutyrate to additional C1-C12 alkyl methacrylate and produce a converted mixture that comprises a C1-C12 alkyl methacrylate, methacrylic acid, C1-C12 alkyl alcohol, and water, wherein the catalyst (1) comprises at least one element selected from the group consisting of lithium, sodium, potassium, rubidium, cesium and francium, (2) is supported on a support comprising porous silica, and (3) comprises from 0.005 to 5 moles of boron as a promoter per 100 moles of silica.