Polymerization of siloxanes

US6346593B1 · kind B1 · utility

Assignee

• Dow Corning Corporation · US

Inventors

• Peter Cheshire Hupfield · Düsseldorf, DE
• Grainne Moloney · Penarth, GB
• Avril Surgenor · Cardiff, GB
• Richard Taylor · Cincinnati, US

Key dates

• Filing date: Dec 9, 1999
• Grant date: Feb 12, 2002
• Expiry date: Dec 9, 2019

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G77/26
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A polymerization process comprising mixing siloxane polymers with organosilicon compounds having at least one silicon-bonded group RN, which is a substituent comprising at least one amine group, and with a phosphazene base catalyst and allowing the siloxanes and organosilicon compounds to polymerize to form amino-functional polyorganosiloxane polymers is claimed. Preferably the phosphazene base is selected from the following formulae:((R12N)3P═N—)x(R12N)3−xP═NR2;{((R12N)3P═N—)x(R12N)3−xP—N(H)R2}+{A−}{((R12N)3P═N—)y(R12N)4−yP}+{A}−or{(R12N)3P═N—(P(NR12)2═N)n—P+(NR12)3}{A−}in which R1 is hydrogen or an optionally substituted hydrocarbon group, or in which two R1 groups bonded to the same N atom may be linked to complete a heterocyclic ring, R2 is hydrogen or an optionally substituted hydrocarbon group, x is 1, 2 or 3; y is 1, 2, 3 or 4, n is an integer with a value of from 1 to 10 and A is an anion.