Polymerization catalyst and polymerization process
AssigneeDow Corning Corporation
InventorsDavid Eglin, Jean de la Cro Habimana, Peter Hupfield, Avril Surgenor, Richard Taylor
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Abstract
Siloxanes are polymerized by equilibration, condensation and/or ring-opening polymerization using a phosphazene base catalyst. A linear phosphazene base catalyst of the general formula wherein R denotes a C1-10 hydrocarbon or wherein two R groups on one N atom form with the N atom a heterocyclic group, X denotes an anion and n is from 1 to 10 is prepared by reacting a linear phosphonitrile halide compound with a secondary amine or a salt of a secondary amine or a metal amide thereof to form an aminated phosphazene material, followed by an ion exchange reaction replacing the anion with a nucleophile.
Claims8
A process for making a linear phosphazene base catalyst comprising reacting a linear phosphonitrile halide compound with a compound selected from secondary amines and salts and metal amides thereof to form an aminated phosphazene material, followed by reacting the aminated phosphazene material in an ion exchange reaction replacing the anion of the aminated phosphazene material with a nucleophile.
A linear phosphazene base catalyst of the general formula (1),
- wherein R denotes a hydrocarbon having up to 10 carbon atoms or wherein the two R groups on each N atom form with the N atom a heterocyclic group, X is fluoride anion, and n has an average value of from 1.2 to 10.
Dependencies are inferred from the claim text.