Compositions which can be crosslinked to form flame retardant and/or tracking resistant and arc resistant organopolysiloxane elastomers

US5008317A · kind A · utility

Assignee

• Wacker Chemie AG · DE

Inventors

• Dietrich Wolfer · Unterhaching, DE
• Wilhelm Marsch · Haiming, DE

Key dates

• Filing date: Sep 14, 1989
• Grant date: Apr 16, 1991
• Expiry date: Sep 14, 2009

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08K2003/2241
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Compositions which can be crosslinked to form flame retardant and/or tracking resistant and arc resistant organopolysiloxane elastomers which comprises adding to a cross-linkable organopolysiloxane an additive which is obtained by mixing PA0 (A) 60 to 80 percent by weight of diorganopolysiloxane having 75 to 85 mol percent of dimethylsiloxane units and 15 to 25 mol percent of vinylmethylsiloxane units, PA0 (B) 20 to 35 percent by weight of a metal oxide selected from the group consisting of titanium dioxide, zirconium dioxide, zinc oxide, Ce(III) oxide and Ce(IV) oxide, PA0 (C) 0.05 to 0.25 percent by weight of platinum, calculated as the element, PA0 (D) 1 to 5 percent by weight of an organosilicon compound having basic nitrogen bonded via carbon to silicon PA1 in which the sum of the percentages (A) to (D) adds up to 100 percent by weight based on the total weight of the additive. In order to achieve tracking resistance and arc resistance, only titanium dioxide or zirconium dioxide are used, while any of the metal oxides can be used to achieve flame resistance. The additive is present in the composition in amounts of from 1 to 4 percent by weight, based on the total weight of the…