Polymeric chlorosilazanes, process for their preparation, ceramic materials containing silicon nitride which can be manufactured therefrom, and their manufacture
CA 2004405 A1 · Owner: Hoechst Aktiengesellschaft · Inventors: Bruck, Martin; Vaahs, Tilo; Peuckert, Marcellus
Overview
Its claims, description and drawings are in the Canadian Patents Database.
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Polymeric chlorosilazanes, process for their preparation ceramic materials containing silicon nitride which can be manufactured therefrom, and their manufacture The invention relates to novel polymeric chlorosilazanes to their preparation, to their processing to form ceramic material containing silicon nitride, and to said material itself. The polymeric chlorosilazanes are prepared by reacting a mixture of oligosilazanes of formula (I) (I) , in which n is about 2 to about 12 and oligosilazanes of, formula (II), (RSiHNH)m in which m is about 3 to about, 12, with at least one of the chlorosilanes Cl2R2Si-CH2-CH2-SiR2Cl2, Cl3Si-CH2-CH2-SiR3Cl2 R4SiCl3 or, R5SiHCl2 at 30°C to 300°C, where R and …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed December 1, 1989. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 1, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 1, 2011.
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