Hydroxymethyltrialkoxysilanes and processes for preparation and use thereof

摘要

Novel hydroxymethyltrialkoxysilanes of the formula: <IMAGE> are prepared by transesterification of a carboxylic acid ester of hydroxymethyltrialkoxysilane with an alcohol and by distillation of the reaction mixture to remove the carboxylate of the alcohol. The carboxylic acid ester of hydroxymethyltrialkoxysilane is prepared by the reaction of an alkali metal carboxylate with chloromethyltrialkoxysilane which, in turn, is produced by the reaction of a trialkyl orthoester with chloromethyltrichlorosilane by heating to reflux with the removal of alkyl chloride, followed by a distillation to remove alkyl ester. The hydroxymethyltrialkoxysilanes and their carboxylic acid esters and carboxymethyltrialkoxysilanes are particularly useful in sol-gel processing, in that they are subjected to hydrolysis to produce hydroxymethylsilane and subsequent hydrolysis and polycondensation products.