HYDROLYSIS OF SILANES

摘要

A process is provided for silane hydrolysis having a good degree of control of reaction rate and presenting mild conditions. The process comprises reacting together a silane having at least one hydrolysable group with water in the presence of a catalyst comprising a rare earth metal salt with a non-nucleophilic ligand. The ligand is selected from trifluoromethanesulfonate, perchlorate, oxalate, acetate and other alkanoate having a chain length of from 2 to 10 carbon atoms, hexafluoroacetylacetonate and acetylacetonate, with triflate as the preferred ligand. The rare earth metal is preferably a lanthanide, especially lanthanum, praseodymium, neodymium, samarium, europium, gadolinium, dysprosium, erbium, thulium or ytterbium. The hydrolysis product may be used in a subsequent surface treatments of materials having a superficial oxide or hydroxide layer or the hydrolysis may alternatively be carried out directly in the presence of the surface to be treated. The process is also useful in the production of silicon-based gels such as solvogels and alcogels and for the formation of silane crosslinked polymers.