Silicon boron nitride ceramic and precursor compounds, a process for their preparation and their use
AssigneeBayer Aktiengesellschaft
InventorsMartin Jansen, Hans-Peter Baldus, Oliver Wagner
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Abstract
Silicon boron nitride ceramics are produced from polyborosilizanes obtained from polymerized Cl.sub.3 Si--NH--BClX wherein X is --Cl or --NH--Si--Cl.sub.3.
Claims6
A process for the preparation of a silicon boron nitride ceramic powder wherein trichlorosilylamino-boranes having the formula Cl.sub.3 Si--NH--BClX, wherein X is --Cl or --NH--Si--Cl.sub.3 are ammonolyzed with solid, liquid or gaseous ammonia at temperatures of from -200.degree. C. to 1400.degree. C. and the resulting product is calcined in N.sub.2, argon, NH.sub.3 or mixtures thereof at temperatures of from 800.degree. to 1400.degree. C.
A process for the preparation of ceramic material which comprises pyrolyzing oligomeric or polymeric polyborosilazane compounds in an inert or NH.sub.3 -containing atmosphere at temperatures of from 800.degree. to 2100.degree. C., wherein said oligomeric or polymeric polyborosilazane compounds contain repeating structural units .tbd.Si--NH--B.tbd., wherein the first coordination sphere of each silicon or boron atom consists only of nitrogen atoms which are substituted by a group R wherein R is H, C.sub.1 -C.sub.6 -alkyl, vinyl or phenyl.
Ceramic fibers, ceramic coatings and ceramic molded products produced from oligomeric or polymeric polyborosilazane compounds containing repeating structural units .tbd.Si--NH--B.tbd., wherein the first coordination sphere of each silicon or boron atom consists only of nitrogen atoms which are substituted by a group R wherein R is H, C.sub.1 -C.sub.6 -alkyl, vinyl or phenyl.
Dependencies are inferred from the claim text.