Transparent storage-stable polysiloxanes which cross-link under atmospheric conditions

US4001168A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Gunther Maass · Bensberg, DE
• Hans Joachim Lucking · Leverkusen, DE
• Hans Sattlegger · Odenthal, DE
• Karl-Heinz Rudolph · Bottrop, DE

Key dates

• Filing date: Mar 18, 1975
• Grant date: Jan 4, 1977
• Expiry date: Mar 18, 1995

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08K5/54
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A polysiloxane composition which can be cross-linked under atmospheric conditions and which consists essentially of: A. 100 parts by weight of an .alpha.,.omega.-dihydroxymethylphenylpolysiloxane with about 7-15 mole % of diphenylsiloxy units or about 14-28 mole % of methylphenylsiloxy units, and having a viscosity of between about 1,000 and 500,000 cSt (at 20.degree. C), b. about 1 to 40 parts by weight of an uncoated reinforcing filler consisting essentially of SiO.sub.2 having a specific surface area of about 40 to 500 m.sup.2 /g by the BET method, and C. about 1 to 10 parts by weight of a cross-linking agent of the formula EQU RSiX.sub.3 wherein PA1 R is an alkyl, halogenoalkyl, aryl, or arylalkyl radical, and PA1 X is an alkoxy, acyloxy, oximato or alkylamino radical. A curing catalyst may also be present. The composition is clear as are the silicone rubbers produced upon curing.