Process for controlling the rate of platinum induced addition reaction of silicon bonded hydrogen atoms to organopolysiloxanes containing aliphatic unsaturation

US4096159A · kind A · utility

Assignee

• Wacker Chemie AG · DE

Inventors

• Wolfgang Hechtl · Burghausen, DE
• Ernst Wohlfahrt
• Richard Schmidlkofer

Key dates

• Filing date: Sep 30, 1977
• Grant date: Jun 20, 1978
• Expiry date: Sep 30, 1997

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G77/20
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A process for controlling the rate of addition of silicon bonded hydrogen atoms to organopolysiloxanes containing aliphatic unsaturation which comprises mixing (1) an organopolysiloxane containing silicon bonded hydrogen atoms and/or (2) an organopolysiloxane containing at least 50 silicon atoms per molecule and having aliphatically unsaturated groups with at least one organosilicon compound of the formula EQU CH.sub.2 .dbd.CHR.sub.2 SiO(SiR.sub.2 O).sub.n SiR.sub.2 CH.dbd.CH.sub.2 in which R is a hydrocarbon radical or a substituted hydrocarbon radical free of aliphatic unsaturation and n is a number of from 0 to 6 prior to combining the organopolysiloxanes (1) and (2) in the presence of a platinum catalyst. The composition thus obtained has a substantially longer pot-life while only slightly extending the curing time.