Room temperature vulcanising compositions.

摘要

This application is concerned with room temperature vulcanising compositions useful as mould making materials which are formed by mixing an alpha, omega dihydroxy polysiloxane, a condensation polydimethylsiloxane, catalyst and a crosslinking agent which comprises a tri- or tetra- alkoxy silane or siloxane in which the alkoxy groups contain more than two carbon atoms. Moulds made with these materials on epoxy masters show improved usage; the improvement is related to the size of the alkoxy "leaving group" and the proportion of crosslinker and condensation catalyst.