| 摘要 |
HOE 88/ F 345 Polysubstituted chlorine-containing silazane polymers, process for their preparation, ceramic materials containing silicon nitride which can be manufactured therefrom, and their manufacture The invention relates to novel polysubstituted chlorinecontaining silazane polymers, to their preparation, to their processing to form ceramic material containing silicon nitride, and to said material itself. The chlorine-containing silazane polymers are prepared by reacting oligosilazanes of formula (I) in which at least one of the indices a or b and at least one of the indices c or d are not equal to 0 and n is about 2 to about 12, with at least one of the chlorosilanes Cl2R6Si-CH2CH2-SiR6Cl2, Cl3Si-CH2CH2-SiR7Cl2, R8SiCl3 or R9SiHCl2 at 30.degree.C to 300.degree.C, where the radicals independently of one another have the following meanings: R1, R2, R4 = H, C1-C6 alkyl or C2-C6 alkenyl and R3, R5, R6, R7, R8, R9 = C1-C6 alkyl or C2-C6 alkenyl. The polysubstituted chlorine-containing silazane polymers according to the invention can be converted into polysilazanes by reaction with ammonia, and these in turn can be pyrolyzed to form ceramic materials containing silicon nitride.
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