POLYMERIC CHLOROSILAZANE CROSSLINKED WITH ETHYLENE, PREPARATION THEREOF, CERAMIC MATERIAL WHICH CONTAINS SILICON NITRIDE AND CAN BE PRODUCED THEREFROM, AND MANUFACTURE OF SAID CERAMIC MATERIAL

摘要

The invention relates to novel polymeric ethylene-bridged chlorosilazanes, their preparation, their further processing to give silicon nitride containing ceramic material, and to this material itself. For the preparation of the polymeric chlorosilazanes, oligosilazanes of the formula (I) …… are reacted with at least one of the chlorosilanes …… R<4>SiCl3 or R<5>SiHCl2, where R<1> to R<5> are C1-C6-alkyl or C2-C6-alkenyl groups which can be identical or different. …The polymeric chlorosilazanes according to the invention can be converted by reaction with ammonia into polysilazanes which, in turn, can be pyrolysed to give silicon nitride-containing ceramic materials.