FORMKÖRPER AUF BASIS VON PYROGEN HERGESTELLTEM SILICIUMDIOXID

摘要

Moldings based on silica having a hollow cylindrical configuration with internal reinforcing stays or spokes leading from an inner wall of a hollow cylinder to the center of the molding or in the form of miniliths having passageway channels therethrough, are produced by homogenizing silica with methyl hydroxyethyl cellulose, wax and/or polyethylene glycol. Water and optionally aqueous alkaline ammonia solution are added, and the mixture is subjected to kneading and forming, extruding, optionally cutting the extrudate to the desired length by means of a cutting device, drying at a temperature from 20 to 150° C., and annealing for a period from 30 minutes to 10 hours at a temperature of 400 to 1200° C. The moldings can be used as catalyst supports for the production of unsaturated esters from olefins, organic acids and oxygen in the gas phase and and can be used in particular for the production of vinyl acetate monomer.