Polymeric ethylene-bridged chlorosilazanes, process for their preparation, ceramic materials which can be prepared from them containing silicon nitride, and their preparation

US5011801A · kind A · utility

Inventors

• Tilo Vaahs · Kelkheim, DE
• Marcellus Peuckert · Hofheim, DE
• Martin Bruck · Hofheim, DE

Key dates

• Filing date: Nov 30, 1989
• Grant date: Apr 30, 1991
• Expiry date: Nov 30, 2009

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C04B35/589
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Polymeric ethylene-bridged chlorosilazanes, process for their preparation, ceramic materials which can be prepared from them containing silicon nitride, and their preparation The invention relates to novel polymeric ethylene-bridged chlorosilazanes, their preparation, their further processing to a ceramic material containing silicon nitride, and this material itself. In order to prepare the polymeric chlorosilazanes, oligosilazanes of the formula (I) ##STR1## are reacted with at least one of the chlorosilanes ##STR2## in which R.sup.1 to R.sup.5 are C.sub.1 -C.sub.6 -alkyl or C.sub.2 -C.sub.6 -alkenyl groups, which may be identical or different. The polymeric chlorosilazanes according to the invention can be converted by reaction with ammonia into polysilazanes, which in their turn can be pyrolysed to ceramic materials containing silicon nitride.