Room temperature crosslinking, one component silicone rubber formulation with hydrophobic silica

US6956080B2 · kind B2 · utility

Assignee

• Degussa AG · DE

Inventors

• Mario Scholz · Zöblitz, DE
• Michael Kempf · Rodenbach, DE
• Christian Panz · Wesseling, DE
• Kenichi Kawamoto · Tokyo, JP

Key dates

• Filing date: Jan 16, 2003
• Grant date: Oct 18, 2005
• Expiry date: May 4, 2023

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01P2006/40
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A room temperature crosslinking, one component (RTV 1C) silicone rubber formulation with hydrophobic, silica featuring extremely low water absorption, a high level of whiteness, and fine-tunable, storage-stable rheological properties with a high reinforcing action in the silicone rubber vulcanizate contains A) from 0.5 to 60% by weight of a hydrophobic silica having the following properties: a carbon content of >3.1%; a methanol wettability of >60%; a reflectance of >94%; a BET/CTAB ratio of from >1 to <3; a DBP absorption of <230 g/100 g; a BET surface area of from 50 to 110 m2/g; a CTAB surface area of >30 m2/g; a water vapor absorption at 30° C. at an ambient humidity of 30 of <1.3; a water vapor absorption at 30° C. at an ambient humidity of 70 of <1.7; and B) 40-99.5% by weight of an organopolysiloxane of the formulaZnSiR3-n—O—[SiR2O]x—SiR3-n—Z′nwherein each R represents independently alkyl, acetoxy, oxime, alkoxy, amido, aryl or alkenyl radicals, each having from 1 to 50 carbon atoms, each unsubstituted or substituted identically or differently by O, S, F, Cl, Br or I; or R represents independently polystyrene, polyvinyl acetate, polyacrylate, polymethacrylate, or polyacrylon…