Abstract: A process for the preparation of silyl ketene acetals of the formulae,R.sup.1 R.sup.2 C=C(OR.sup.3)OSiR.sub.3.sup.4 and R.sup.1 R.sup.2 C=C[OSiR.sub.3.sup.4 ].sub.2,from the reaction of a malonate compound with a triorganohalosilane in the presence of an alkali metal. The malonate compounds are dialkyl dialkylmalonates, bis(trialkylsilyl) dialkylmalonates, and dialkylmalonic acids. The triorganohalosilane is present in stoichiometric excess relative to the malonate compounds. Silyl ketene acetals are isolated and separated.

Abstract: The present invention relates to a process for the preparation of alkoxy, aryloxy, alkyl, and aryl cyclotetrasiloxanes from a metal silicate halide salt, Ca.sub.8 Si.sub.4 O.sub.12 Cl.sub.8.

Abstract: Vinyl-containing polysilanes are described wherein the vinyl groups are attached to endblocking sites of intermediate reactivity. These vinyl-containing polysilanes are prepared by reacting a halogen-endblocked polysilane with, first, a non-vinyl-containing Grignard reagent or a non-vinyl organolithium compound whereby the most reactive halogen endblocking groups are replaced; then, second, reacting the resulting polysilane with vinyl Grignard reagent or vinyllithium whereby the halogen endblocking groups of intermediate reactivity are replaced; and, third, reacting the resulting polysilane with a non-vinyl-containing Grignard reagent or a non-vinyl organolithium compound whereby the least reactive halogen endblocking groups are replaced. The vinyl-containing polysilanes can be coverted to ceramic materials, including ceramic fibers, by pyrolysis.

Abstract: This invention relates to materials produced by diluting in a solvent a platinum or rhodium catalyzed preceramic mixture of a hydrogen silsesquioxane resin. The preceramic mixture solvent solution is applied to a substrate and ceramified by heating. One or more ceramic coatings containing silicon carbon, silicon nitrogen, or silicon carbon nitrogen can be applied over the ceramified SiO.sub.2 coating. A CVD or PECVD top coating can be applied for further protection. The invention is particularly useful for coating electronic devices.

Abstract: The invention relates to the selective and stepwise reduction of polyhalosilanes by reacting at room temperature or below with alkyltin hydrides without the use of free radical intermediates. Alkyltin hydrides selectively and stepwise reduce the Si--Br, Si--Cl, or Si--I bonds while leaving intact any Si--F bonds. When two or more different halogens are present on the polyhalosilane, the halogen with the highest atomic weight is preferentially reduced.

Abstract: This invention relates to materials produced by diluting in a solvent a preceramic mixture of a hydrogen silsesquioxane resin and a metal oxide precursor selected from the group consisting of an aluminum alkoxide, a titanium alkoxide, and a zirconium alkoxide. The preceramic mixture solvent solution is applied to a substrate and ceramified by heating. One or more ceramic coatings containing silicon carbon, silicon nitrogen, or silicon carbon nitrogen can be applied over the ceramified SiO.sub.2 /metal oxide coating. A CVD or PECVD top coating can be applied for further protection. The invention is particularly useful for coating electronic devices.

Abstract: A process for preparing polysilanes of the general formula (RSi).sub.n wherein each R denotes independently an alkyl, aryl, alkaryl or aralkyl group having from 1 to 18 carbon atoms and n is at least 8, comprises reacting at least one silane of the general formula RSiX.sub.3 wherein R is as defined above and X denotes a halogen atom with an alkali metal in an organic liquid medium in which the silane is soluble, preferably tetrahydrofuran.

Abstract: Preceramic actylenic polysilanes are described which contain --(CH.sub.2).sub.w C.tbd.CR' groups attached to silicon where w is an integer from 0 to 3 and where R' is hydrogen, an alkyl radical containing 1 to 6 carbon atoms, a phenyl radical, or an --SiR"'.sub.3 radical wherein R"' is an alkyl radical containing 1 to 4 carbon atoms. The acetylenic polysilanes are prepared by reacting chlorine- or bromine-containing polysilanes with either a Grignard reagent of general formula R'C.tbd.C(CH.sub.2).sub.w MgX' where w is an integer from 0 to 3 and X' is chlorine, bromine, or iodine or an organolithium compound of general formula R'C.tbd.C(CH.sub.2).sub.w Li where w is an integer from 0 to 3. The acetylenic polysilanes can be converted to ceramic materials by pyrolysis at elevated temperatures under an inert atmosphere.

Abstract: Preceramic polymers composed of [R.sub.2 SiC.tbd.CSiR.sub.2 ] and, optionally, [R.sub.2 Si] units are described where R is hydrogen, an alkyl radicals containing 1 to 8 carbon atoms, phenyl radicals, or vinyl radicals. These preceramic polymers may be converted into silicon carbide-containing ceramic materials by pyrolysis at elevated temperatures.

Abstract: The invention relates to the selective and sequential reduction of halodisilanes by reacting these compounds at room temperature or below with trialkyltin hydrides or dialkyltin dihydrides without the use of free radical intermediates. The alkyltin hydrides selectively and sequentially reduce the Si-Cl, Si-Br or Si-I bonds while leaving intact the Si-Si and Si-F bonds present.

Abstract: Polydisilacyclobutasilazanes are prepared by a process of reacting chlorodisilacyclobutane with cyclic silazanes. The polymers are crosslinkable and ceramifiable.

Abstract: The invention relates to a method of forming amorphous, photoconductive, and semiconductive silicon films on a substrate by the vapor phase thermal decomposition of a fluorohydridodisilane or a mixture of fluorohydridodisilanes. The invention is useful for the protection of surfaces including electronic devices.

Abstract: A process for the preparation of preceramic metallopolysilanes is described. The process consists of contacting and reacting organohalogendisilanes with metal-containing compounds in the presence of a redistribution catalyst in an inert, essentially anhydrous atmosphere while removing volatile byproducts. The resulting metallopolysilanes contain significant amounts of aluminum, boron, chromium, lanthanum, molybdenum, neodymium, niobium, samarium, tantalum, titanium, tungsten, vanadium, yttrium, or zirconium. Such metallopolysilanes can be prepared with relatively low oxygen levels. These polymers are useful as chemical intermediates to synthesize organosilicon materials or polymers. These polymers are also useful, when fired at high temperatures, to form ceramic materials.

Abstract: Halogenated polycarbosilanes are prepared by reacting a polycarbosilane containing at least 0.1 weight percent Si-H groups with a halogenating reagent selected from the group consisting of chlorine, bromine, phosphorous pentachloride, phosphorous pentabromide, antimony pentachloride, N-chlorosuccinimide, N-bromosuccinimide, sulfonyl chloride, and mixtures of CH.sub.e X.sub.f and a free radical initiator where e is 0 or 1, f is 3 or 4, the sum (e+f) is 4, and X is chlorine or bromine. The halogenated polycarbosilanes can be further treated to produce other derivatized polycarbosilanes. The halogenated and derivatized polycarbosilanes can be converted to silicon carbide-containing ceramic materials by pyrolysis at elevated temperatures under an inert atmosphere.

Abstract: The invention relates to a method of preparing allyl-terminated polyisobutylene (PIB) by allylation with allyltrimethylsilane of tertiary chloro-capped PIB by electrophilic substitution. The synthesis begins with the BCl.sub.3, catalyzed mono- or oligo-tertiary chloride "inifer" initiated polymerization of isobutylene, followed in the same reaction vessel by the addition of hexane, allyltrimethylsilane, and TiCl.sub.4.

Abstract: This invention relates to materials produced by diluting in a solvent a hydrogen silsesquioxane resin solvent solution which is applied to a substrate and ceramified by heating. One or more ceramic coatings containing silicon carbon, silicon nitrogen, or silicon carbon nitrogen can be applied over the ceramified SiO.sub.2 coating. A CVD or PECVD top coating can be applied for further protection. The invention is particularly useful for coating electronic devices.

Abstract: This invention relates to materials produced by diluting in a solvent a preceramic mixture of a partially hydrolyzed silicate ester and a metal oxide precursor selected from the group consisting of an aluminum alkoxide, a titanium alkoxide, and a zirconium alkoxide. The preceramic mixture solvent solution is applied to a substrate and ceramified by heating. One or more ceramic coatings containing silicon carbon, silicon nitrogen, or silicon carbon nitrogen can be applied over the ceramified SiO.sub.2 /metal oxide coating. A CVD or PECVD top coating can be applied for further protection. The invention is particularly useful for coating electronic devices.

Abstract: This invention relates to materials produced by diluting in a solvent a preceramic mixture of a hydrogen silsesquioxane resin and a metal oxide precursor selected from the group consisting of an aluminum alkoxide, a titanium alkoxide, and a zirconium alkoxide. The preceramic mixture solvent solution is applied to a substrate and ceramified by heating. One or more ceramic coatings containing silicon carbon, silicon nitrogen, or silicon carbon nitrogen can be applied over the ceramified SiO.sub.2 /metal oxide coating. A CVD or PECVD top coating can be applied for further protection. The invention is particularly useful for coating electronic devices.

Abstract: This invention relates to materials produced by diluting in a solvent a preceramic mixture of a partially hydrolyzed silicate ester which is applied to a substrate and ceramified by heating. One or more ceramic coatings containing silicon carbon, silicon nitrogen, or silicon carbon nitrogen can be applied over the ceramified SiO.sub.2 coating. A CVD or PECVD top coating can be applied for further protection. The invention is particularly useful for coating electronic devices.

Abstract: This invention deals with new and novel polysilazane polymers, a method for their preparation, and the ceramic materials prepared thereby. An example of such a material is one which is prepared by the reaction of HSiCl.sub.3 and {(CH.sub.3).sub.2 SiNH}.sub.x.