Process for preparing fluoropolyethers and perfluoropolyethers having neutral or functional end groups and a controlled molecular weight

摘要

This invention relates to a process for preparing fluoropolyethers and perfluoropolyethers having neutral and/or functional end groups and a lower molecular weight by a selective catalytic cleavage of the corresponding higher molecular weight fluoropolyethers and perfluoropolyethers, characterized in that said cleavage is carried out by operating in the presence of a catalyst system consisting of a combination of silicon dioxide with at least an oxide, a fluoride or an oxyfluoride of a metal selected from Al, Ti, V, Cr, Co. Fe, Ni, Mo, Zn, Cu, Cd, Mn, Sb, Sn, Zr, Sc, Y, La and homologs thereof, Pb, Mg, W.