Silicone rubber composition with prolonged potlife

• Main Authors: KUHN, ARVID, DIETL, STEFAN, GUSKE, WERNER
• Format: Patent
• Language: English; French; German
• Published: 26.12.2007
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP

Silicone rubber composition (I) comprises 100 parts by weight of at least diorganopolysiloxane (a); 1-100 parts by weight of highly dispersed silicic acid (b); 50-300 parts by weight of at least of an aluminum hydroxide powder (c); cross linkage material (d); and (e) 0.01-10 parts by weight of an inorganic, organic or silicium organic base or acid or a compound, that releases inorganic, organic or silicium organic base or acid in warming. Silicone rubber composition (I) comprises 100 parts by weight of at least diorganopolysiloxane (a) of formula (R 1>aaR 2>bSiO (4-a-b)/2); 1-100 parts by weight (related to 100 parts by weight of (a)) of highly dispersed silicic acid (b) with a specific surface of 50-300 m 2>/g, measured with the BET method; 50-300 parts by weight (related to 100 parts by weight of (a)) of at least of an aluminum hydroxide powder (c) with a specific surface of 0.1-20 m 2>/g and an average particle size of 0.05-20 mu m, measured after the BET method; cross linkage material (d) in a quantity, in order to harden (I), where (d) is an organic peroxide and/or hydrogen peroxide, a combination of a organohydrogen polysiloxane (d2) of formula (R c3>H dSiO (4-c-d)/2) or a hydrosilylating catalyst containing at least a transition metal; and (e) 0.01-10 parts by weight (related to 100 parts by weight of (a)) of an (in)organic or silicium organic base/acid or a compound, that releases inorganic, organic or silicium organic base or acid in warming. R 1>optionally halo substituted univalent hydrocarbon residue with 1-20C atoms, which is free of aliphatic unsaturated groups; R 2>optionally halo substituted univalent hydrocarbon residue, which contains at least an aliphatic carbon-carbon-multiple bond, where each molecule on the average exhibits at least two such univalent hydrocarbon residues bounded to silicium atoms containing aliphatic carbon-carbon-multiple bonds; R 3>optionally substituted univalent hydrocarbon residue, which is non-aliphatic unsaturated, where each molecule on an average exhibits at least three such hydrogen atoms bound to silicium atoms; and c, d : positive numbers. Provided that c is 1-3, d is 0-1 and the sum of c and d is 1-3. Independent claims are also included for the preparation of (I); and silicone rubber obtained by cross-linking of (I).