SYNERGISTIC HTV/RTV SILICONE MATERIAL
Original Publication Date: 1980-Jun-30
Included in the Prior Art Database: 2004-Apr-02
Xerox Disclosure Journal
For many applications for which silicone elastomeric materials are uniquely suited, high temperature vulcanizable (HTV) silicone materials can be advantageously used. However, when HTV silicone materials are highly loaded with fillers, for thermal conductivity or strengthening purposes, cracking and failure of the elastomers frequently occur at polymer-filler interface. The present invention provides a HTV silicone composition in which the filler and the crosslinking agent are first coated with a room temperature vulcanizable (RTV) silicone elastomer material prior to incorporation into the HTV composition. The RTV material appears to provide better wetting of the filler. The coating of the crosslinking agent with the RTV material also results in more flexible crosslinkages in the final elastomer. These factors result in an elastomeric composition which is more flexible and has higher strength and is less likely to develop failures at the polymer-filler interface.