Process for making polysilsequioxane and

Abstract

A process of making an improved coating composition by combining alkyltrialkoxy silanes such as n-hexyltrimethoxysilane and methyltrimethoxysilane, in the presence of a silane catalyst having at least one amino-substituted functional group, at least one alkoxy-substituted group wherein the alkoxy-substituted group has at least 2 carbon atoms in the alkoxy group and optionally, an alkyl group, in an amount of water less than a stoichiometric amount of water. The combined monomer, catalyst and water are ultrasonically agitated to form an emulsion to hydrolyze the silanes to the extent permitted by the amount of water present and to form a moisture-curable coating composition. The coating composition of the present invention is a moisture-curable polymethyl-n-hexylsilsesquioxane having a partially water-hydrolyzed, silane catalyst-containing condensation product of n-hexyltrimethoxysilane and methyltrimethoxysilane, the silane catalyst having at least one aminoalkyl-substituted group and at least one alkoxy-substituted group having at least 2 carbon atoms in the alkoxy group. The silane catalyst is also a co-curing agent and condenses with the n-hexyltrimethoxysilane and the methyltrimethoxysilane.