Polymerization catalyst and polymerization process

US6448196B1 · kind B1 · utility

Assignee

• Dow Corning Corporation · US

Inventors

• David Olivier EGLIN · Davos, CH
• Jean de la Cro Habimana · Braine-le-Comte, BE
• Peter Cheshire Hupfield · Düsseldorf, DE
• Avril Surgenor · Cardiff, GB
• Richard Taylor · Cincinnati, US

Key dates

• Filing date: Dec 9, 1999
• Grant date: Sep 10, 2002
• Expiry date: Dec 9, 2019

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07F9/067
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

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.