Procédé de préparation d'une composition catalytique de phosphazène utile pour la polycondensation et la redistribution de polymères d'organosiloxane.

摘要

The process according to the invention provides a catalytic composition of low halide content which has a superior catalytic activity. The process includes the reaction of a halophosphonitrile of formula: in which X is a halogen, the values of n may vary from 0 to 6, E denotes phosphorus or another element which has an electronegativity of 1 to 2 according to Pauling's scale, for example aluminium, antimony, iron and the like, and v is the valency or the oxidation state at equilibrium, with a compound containing an active proton and which has a pKa value lower than 18, until the formation of a catalytic composition which has a superior catalytic activity has been practically completely finished. Application to the polycondensation and redistribution of organosiloxane polymers.