Elastomeric organopolysiloxanes containing polycarbodiimide-polysiloxane copolymers

US4548999A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Helmut Steinberger · Leverkusen, DE
• Hans-Heinrich Moretto · Cologne, DE
• Werner Michel · Cologne, DE
• Wilfried Kniege · Bensberg, DE

Key dates

• Filing date: Feb 5, 1981
• Grant date: Oct 22, 1985
• Expiry date: Feb 5, 2001

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G77/455
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A composition which is heat curable to give an elastomer of improved properties comprising PA1 (a) an organopolysiloxane polymer having a viscosity of 1,000,000 to 200,000 mPas at 25.degree. C. and comprising the structural unit ##EQU1## wherein R is a hydrocarbon radical or a halohydrocarbon radical, and PA1 a is between about 1.95 and 2.01, PA1 (b) a polycarbodiimide-polysiloxane copolymer comprising a polysiloxane continuous liquid phase containing a discontinuous phase of finely dispersed polycarbodiimide particles produced by condensing a diisocyanate in the polysiloxane, PA1 (c) a curing catalyst, and PA1 (d) a filler, the polycarbodiimide comprising about 0.1 to 80% by weight of (a) plus (b). Upon curing, the permanent set of the elastomer is reduced and/or the resistance to hydrolytic degradation is improved.