Abstract: A process for reducing the halogen content of polycarbosilanes and/or polysilanes containing halogen bonded directly to silicon atoms by reacting the polymers with hexamethyldisilazane.

Abstract: This invention is concerned with novel polysilanes containing olefinic groups which are prepared by reactions of halogen-containing organosilane monomers or mixtures thereof with sodium metal in an appropriate solvent or mixture of solvents. Such polysilane polymers are soluble and thermoplastic, and can be directly converted to silicon carbide compositions by pyrolysis at atmospheric pressure.

Abstract: The present application relates to novel silicon based preceramic polymers useful in the production of silicon carbide reinforcement fibers, and to the novel synthesis procedures by which such polymers and reinforcement fibers may be produced.These novel polymers are produced by preparing phenyl substituted polyalkylcyclohexasilane compounds, which are then converted to the corresponding halogen substituted compound by reaction with the appropriate ammonium halide and sulfuric acid in a suitable solvent such as benzene, and then polymerizing the substituted cyclohexasilane by reaction with an alkali metal, again in a suitable solvent such as toluene or benzene, to produce polymers of the general formula: ##STR1## wherein R.sub.1 is lower alkyl, preferably methyl or ethyl, R.sub.2 is lower alkyl or hydrogen, m is 0 to 5, n is at least 3. The polymers of the present invention have an average molecular weight of from about 1000 to 100 million or more.

Abstract: Polysilane polymers in which the Si backbone is interrupted by atoms such as O, Ge, Sn, P, etc., are useful photoresists especially in the solvent development mode.

Abstract: A process for the preparation of hexaalkyldisilane. A trialkylsilane halide is brought into contact with an alkali metal, a salt and a phase transfer agent.

Abstract: A dimethylphenysilylmethylpolysilane is prepared by condensating 1,1-dichloro-1,2,2-trimethyl-2-phenyldisilane in the presence of an alkali metal or alkali earth metal, in an aprotic solvent. This polymer is a viscous liquid which has a weight average molecular weight in the range of from 5,000 to 500,000 and a narrow molecular weight distribution, and has various uses as electroconductors, photoresist and optical information recording materials.

Abstract: A 1,2,2-trimethyl-1-phenylpolydisilane is prepared by condensating 1,2-dichloro-1,2,2-trimethyl-1-phenyldisilane in the presence of an alkali metal or alkali earth metal, in an aprotic solvent. This polymer is a viscous liquid which has a weight average molecular weight in the range of from 5,000 to 500,000 and a narrow molecular weight distribution, and has various uses as electroconductors, photoresist and optical information recording materials.

Abstract: A method of forming preceramic polymers by mixing (A) an organic polysilane, preferably either a methylpolysilane of the formula [(RSiH).sub.x (RSi).sub.y ].sub.n, (where R is a lower alkyl group having from 1 to about 6 carbon atoms, a cycloalkyl group having from 3 to about 6 carbon atoms, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, a tri(lower)alkyl- or di(lower)alkylsilyl group x+y=1, (x and y are each >0 and also x=1, y=0), and n is an integer greater than 1) or a polycarbosilane having repeat units of the formula [R.sup.a Si(H)--(CH.sub.2).sub.q ], [R.sup.a Si(H)--CH.dbd.CH], and [R.sup.a Si(H)--C.tbd.C] (where R.sup.

Abstract: This invention relates to 1,2-dichloro-1,2,2-trimethyl-1-phenyldisilane expressed by the chemical formula (II),Cl(CH.sub.3).sub.2 SiSi(CH.sub.3)(C.sub.6 H.sub.5)Cl.This invention further relates to a method for producing 1,2-dichloro-1,2,2-trimethyl-1-phenyldisilane by reacting phenyl lithium with 1,1,2-trichloro-1,2,2-trimethyldisilane expressed by the chemical formula (III),Cl(CH.sub.3).sub.2 SiSi(CH.sub.3)Cl.sub.2.This invention still further relates to a method for producing 1,2-dichloro-1,2,2-trimethyl-1-phenyldisilane by reacting 1,1,2-trichloro-1,2,2-trimethyldisilane with phenylmagnesium halide expressed by the general formula (IV), C.sub.6 H.sub.5 MgX (X=halogen atom) in the presence of a cobalt catalyst.

Abstract: This invention relates to a novel asymmetric 1,1-dichloro-1,2,2-trimethyl-2-phenyldisilane expressed by the chemical formula (I), (C.sub.6 H.sub.5) (CH.sub.3).sub.2 SiSi(CH.sub.3)Cl.sub.2.This invention further relates to a method for producing 1,1-dichloro-1,2,2-trimethyl-2-phenyl disilane by reacting 1,1,2-trichloro-1,2,2-trimethyl disilane expressed by the chemical formula (III), Cl(CH.sub.3).sub.2 SiSi(CH.sub.3)Cl.sub.2 with phenyl magnesium halide expressed by the general formula (IV), C.sub.6 H.sub.5 MgX (X=halogen atom) in the presence of a transition metal (except for cobalt) catalyst.

Abstract: A polyhydridosilane has a catenated silicon backbone of 9 to 4000 silicon atoms with an average number of hydrogen atoms per silicon atom in the range of 0.3 to 2.2, at least 0.1 gram of the polyhydridosilane being soluble at 20.degree. C. in 100 grams of tetrahydrofuran, toluene, or methylene chloride. The polyhydridosilane can be derivatized or it can be converted to a pyropolymer or a nitrogen-containing pyropolymer which is useful as an abrasive, ceramic, electrical, or electro-optical material.

Abstract: Silahydrocarbons such as tetraorganosilanes prepared from halo-substituted silanes and an organomagnesium compound in the presence of a catalytically effective amount of a thiocyanate.

Abstract: Organopolysilanes are prepared by reacting at least one disilane of the formulaR.sub.2 R.sup.1 Si.sub.2 (OCH.sub.3).sub.3,which may optionally be mixed with a compound of the formulaR.sub.2 Si.sub.2 (OCH.sub.3).sub.4,with at least one compound of the formulaR.sub.2 R.sup.2 SiHin the presence of at least one compound of the formulaMOR,where R represents the same or different monovalent alkyl, alkenyl or aryl groups, R.sup.1 represents the same or different monovalent alkyl groups, R.sup.2 represents a methoxy group or R and M represents an alkali metal. These organopolysilanes are preferably used in preparing silicon carbide and in preparing negative photo-resist coatings.

Abstract: A curable silicone composition comprising (A) an organosilicon compound having at least two radicals of the formula: ViSi(R.sup.1).sub.2 Si(R.sup.1).sub.2 --Z-- wherein R.sup.1 is a lower alkyl radical and Z is a bivalent radical of --O-- or --CH.sub.2).sub.n in which n is an integer of 1 to 3, (B) a platinum catalyst, and optionally (C) an organosilicon compound having silicon bonded vinyl groups. The composition is cured through a new crosslinking mechanism without any byproducts, and has high stability at normal temperatures and good curability.

Abstract: Silahydrocarbons such as tetraorganosilanes prepared from halo-substituted silanes and an organomagnesium compound in the presence of a catalytically effective amount of a cyanide.

Abstract: A method of forming preceramic polymers by mixing (A) a methylpolysilane of the formula [(RSiH).sub.x (RSi).sub.y ].sub.n, (where R is a lower alkyl group having from 1 to about 6 carbon atoms, a cycloalkyl group having from 3 about to 6 carbon atoms, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, a tri(lower)alkyl- or di(lower)alkylsilyl group x+y=1, (x and y are each >0 and also x=l, y=o), and n is an integer greater than 1 with (B) an organic or organisilicon compound having at least two alkenyl groups and allowing the mixture to react is disclosed. Preferably, the alkenyl group is a vinyl group. The reaction is preferably initiated by the generation of reactive free radicals. Novel preceramic polymers formed by this method are also disclosed.

Abstract: Linear polysilane-siloxane copolymers having remarkable sensitivity to radiation have the general formula[(SiMe.sub.2).sub.m ].sub.a [(OSiMeR).sub.n ].sub.bwherein Me is a methyl group, R is lower alkyl or phenyl, m=4 to about 30 inclusive, n=1 to about 100 inclusive, a and b may each be 1 to about 10 inclusive, and a units alternate with b units. The copolymers of the invention may be in the form of oligomers, random copolymers where n=1 to 9, block copolymers where n=10 to 100, and mixed (random and block) copolymers. These copolymers may also be in the form of modified copolymers having reactive functional groups such as acrylate, methacrylate, vinyl or other unsaturated substitutions. The copolymers may be produced by formation of a halogen terminated oligomer of a polysilane or polysilane-siloxane copolymer, followed by coupling the oligomers with themselves or with distinct higher molecular weight silanol terminated siloxane species.

Abstract: Novel high performance disilane/organosilicon resins useful, e.g., as molding powders and textile and building waterproofing agents (either in the form of aqueous dispersions or organic solutions thereof), comprise cohydrolysis/condensation reaction products in heterogeneous solvent medium of admixture of organochlorosilanes and organochlorodisilanes, said admixture comprising:(i) from about 10 to 70 molar % of at least one diorganochlorosilane having the formula R.sub.2 SiCl.sub.2, in which the radicals R, which may be identical or different, are each hydrogen, methyl or phenyl;(ii) from about 30 to 70 molar % of at least one methylchlorodisilane which comprises at least about 30 moles % of tetrachloro-1,2-dimethyldisilane; and(iii) from 0 to about 60 molar % of at least one organotrichlorosilane having the formula R'SiCl.sub.3, in which R' is defined as is R above;and said resins having an average functionality of from about 2.2 to 3.

Abstract: A polyhydridosilane has a catenated silicon backbone of 9 to 4000 silicon atoms with an average number of hydrogen atoms per silicon atom in the range of 0.3 to 2.2, at least 0.1 gram of the polyhydridosilane being soluble at 20.degree. C. in 100 grams of tetrahydrofuran, toluene, or methylene chloride. The polyhydridosilane can be derivatized or it can be converted to a pyropolymer or a nitrogen-containing pyropolymer which is useful as an abrasive, ceramic, electrical, or electro-optical material.

Abstract: The invention provides a novel inorganic fiber composed of the elements of silicon, carbon, boron and nitrogen of which the Si/B molar ratio is 2:1 to 200:1. The inorganic fiber is obtained by a method comprising the steps of: (a) preparing an organoborosilicon polymer by heating a mixture of an organopolysilane and an organoborazine compound, e.g. B-trimethyl-N-triphenyl borazine, to effect thermal decomposition and polycondensation reaction; (b) spinning the polymer into a fibrous form; (c) infusibilizing the fiber of the polymer by thermally oxidizing in an oxidizing atmosphere or by irradiating with ionizing radiations; and (d) calcining the infusibilized fiber at 900.degree. to 1800.degree. C. The inventive inorganic fiber is more stable at high temperatures than conventional silicon carbide fibers.

Abstract: A method for cross-linking organopolysilane polymers. The method includes the steps of mixing an organopolysilane with a cross-linking agent to make a reaction mixture. The cross-linking agent includes molecules having at least two carbon-carbon double bonds and a ratio of such bonds to the molecular weight of the molecule of at least 1:150. Radical formation is then induced in the organopolysilane of the reaction mixture to cause formation of a reaction product including cross-linked organopolysilane polymers.

Abstract: An organosilicon polymer whose main-chain skeleton is composed mainly of following structural units (A), (B), (C), (D), (E) and (F) ##STR1## wherein R represents CH.sub.3 or H, said structural units forming linear, branched and cyclic structures, and said main-chain skeleton further having a polysilane skeleton ##STR2## (2.ltoreq.n.ltoreq.10). The said organosilicon polymer can be produced by adding at least one anhydrous metal halide to a polysilane having the structure ##STR3## the amount of the metal halide being 0.5 to 10% by weight based on the weight of the polysilane; and heating the mixture in an atmosphere inert to the reaction.

Abstract: New polysilane copolymers comprise recurring units of --Si(X)(Y)-- and Si(A)(B)--, Si(X)(Y) being different from Si(A)(B),whereinX and Y together have 1-13 carbon atoms, and X and Y each independently is hydrogen, alkyl, cycloalkyl, phenyl, alkylphenyl, or phenylalkyl, with the proviso that only one of X and Y contains a phenyl moiety, or together X and Y are an alkylene group forming a ring with the adjoining Si atom,and whereinA and B together have 3-13 carbon atoms, and A and B each independently is alkyl or cycloalkyl, with the proviso (a) that when one of A and B is ethyl, the other is not methyl or ethyl, and (b) that when one of A and B is n-propyl and the other is methyl, X and Y are not both methyl.Corresponding homopolysilanes are also provided.Upon ultraviolet irradiation, they photodepolymerize to form volatile products. As a result, they represent a new class of photoresists which enable direct formation of a positive image eliminating the heretofore required development step.

Abstract: New polysilane copolymers comprise recurring units of --Si(X)(Y)-- and Si(A)(B)--, Si(X)(Y) being different from Si(A)(B), whereinX and Y together have 1-13 carbon atoms, and X and Y each independently is hydrogen, alkyl, cycloalkyl, phenyl, alkylphenyl, or phenylalkyl, with the proviso that only one of X and Y contains a phenyl moiety, or together X and Y are an alkylene group forming a ring with the adjoining Si atom, and whereinA and B together have 3-13 carbon atoms, and A and B each independently is alkyl or cycloalkyl, with the proviso (a) that when one of A and B is ethyl, the other is not methyl or ethyl, and (b) that when one of A ad B is n-propyl and the other is methyl, X and Y are not both methyl.Corresponding homopolysilanes are also provided.Upon ultraviolet irradiation, they photodepolymerize to form volatile products. As a result, they represent a new class of photoresists which enable direct formation of a positive image eliminating the heretofore required development step.

Abstract: The organosilanes/organopolysilanes, e.g., methylchlorosilanes useful in the production of silicones, are facilely prepared by contacting, in an inert atmosphere, (1) at least one disilane having the general formula:(R).sub.3 Si--Si--R).sub.3 (I)wherein the radicals R, which may be identical or different, are each C.sub.1 -C.sub.6 alkyl, hydrogen, 3,3,3-trifluoropropyl, trimethylsiloxy, fluorine, chlorine, bromine or iodine, with (2) a catalytically effective amount of a catalyst system comprising (a) at least one ionic inorganic salt having the formula:M.sup.+ A.sup.-wherein M.sup.+ is lithium, sodium, potassium, rubidium or cesium, and A.sup.- is fluoride, chloride, bromide or iodide, and (b) at least one compound which complexes the cation M.sup.+ of said salt (a), e.g., a sequestering agent having the formula:N--CHR.sub.1 --CHR.sub.2 O--CHR.sub.3 CHR.sub.4 O).sub.n R.sub.5 ].sub.3 (II).

Abstract: A polyhydridosilane has a catenated silicon backbone of 9 to 4000 silicon atoms with an average number of hydrogen atoms per silicon atoms in the range of 0.3 to 2.2, at least 0.1 gram of the polyhydridosilane being soluble at 20.degree. C. in 100 grams of tetrahydrofuran, toluene, or methylene chloride. The polyhydridosilane can be derivatized or it can be converted to a pyropolymer or a nitrogen-containing pyropolymer which is useful as an abrasive, ceramic, electrical, or electro-optical material.

Abstract: Mono- or bis(iodonium salts) are produced in neutral organic solvents by the reaction of an [hydroxy (organosulfonyloxy)iodo]arene with a bis(triorganosilyl)arene, a bis(trihalosilyl)arene, or with a mono- or bis(triorganosilyl)heterocyclic compound, or a mono- or bis(trihalosilyl)heterocyclic. The iodonium salts are made under conditions of regiospecific control.

Abstract: A novel branched hydrosilyl-modified polycarbosilane which can be pyrolized to obtain improved yields of silicon carbide. This novel branched hydrosilyl-modified polycarbosilane can be prepared in a one-step reaction from mixtures of silane monomers containing vinyl or halomethyl moieties with silane monomers containing hydrosilyl groups.

Abstract: The invention provides a novel and efficient method for the preparation of methyl hydrogensilanes, e.g. dimethyl silane, 1,1,2,2-tetramethyl disilane and 1,1,2,2,3,3-hexamethyl trisilane, with large demand in the industry of silicones as an intermediate for the synthesis of other valuable organosilicon compounds such as methyl hydrogenchlorosilanes. The inventive method comprises pyrolysis of a methyl polysilane composed of at least 60% by moles of dimethylsilicon units, the balance being monomethyl- and trimethylsilicon units, at a temperature in the range from 350.degree. to 800.degree. C.

Abstract: Silicon carbide can be produced by the pyrolysis of branched polycarbosilanes which in turn are produced directly from selected monomer systems.

Abstract: A process for methylating silicon compounds containing halogen and at least 2 silicon atoms and optionally carbon and hydrogen atoms as the only atoms in the molecule, which comprises reacting a silicon compound containing halogen and at least two silicon atoms per molecule, such as hexachlorodisilane or 1,1,2,2-tetrachloro-1,2-dimethyldisilane or mixtures of such silanes with tetramethylsilane in the presence of at least one organoaluminum compound having the general formulaR.sub.a AlY.sub.3-a'where R represents the same or different alkyl radicals having from 1 to 4 carbon atoms, Y represents halogen, hydrogen or hydrocarbon radicals having from 1 to 10 carbon atoms which are bonded to the aluminum atom via oxygen and which are free of aliphatic multiple bonds, and a is 1, 2 or 3, or an in situ formed compound obtained from the reaction of such aluminum compound, with at least one other reactant present in the reaction mixture, at least one silane of the general formulaR.sub.b.sup.1 H.sub.c SiCl.sub.

Abstract: What is disclosed is a process for preparing polysilazane polymers by contacting and reacting chlorine-containing disilanes with ammonia. The polysilazane polymers are useful as chemical intermediates to produce silicon-containing chemical compounds. They are also useful in the formation of silicon carbide-containing ceramic materials.

Abstract: A process is described for converting the alkyl-rich disilanes in the residue obtained from the manufacture of alkylhalosilanes to halogen-rich polysilanes with alkyltrihalosilanes and simultaneously converting the alkyltrihalosilanes to dialkyldihalosilanes by reacting the alkyl-rich polysilanes in the residue and the alkyltrihalosilanes at an elevated temperature in the presence of a suitable catalyst and a catalytic amount of a hydrosilane reaction promoter. In a preferred embodiment, the residue containing alkyl-rich disilanes is treated with methyltrichlorosilane at a temperature of about 100.degree. C. to about 250.degree. C. in the presence of aluminum trichloride catalyst and a catalytic amount of methyldichlorosilane.

Abstract: A silica-silicone fluid gel, the properties of which are not significantly affected by sterilizing doses of radiation, is prepared by reaction of a silicone fluid having a narrow viscosity distribution with a filler material and a network former at or below about 120.degree. C.

Abstract: A method of preparing polycarbosilanes having high molecular weight and also having the major structural unit of silicon-carbon linkage. The method comprises heating a polysilane at 50.degree.-600.degree. C. in atmosphere of an inert gas and distilling out a low molecular weight polycarbosilane fraction having the number mean molecular weight of 300-600, followed by polymerizing the fraction by heating it at 250.degree.-500.degree. C. in atmosphere of an inert gas. The polycarbosilane obtained by the method of the present invention is useful for the precursor of preparing silicon carbide fibres and shaped articles.

Abstract: The preparation of soluble polysilastyrene comprising reacting phenylmethyldichlorosilane and dimethyldichlorosilane in the mole ratio of 1 to 0.25-2 in the solvent solution in the presence of sodium.

Abstract: Pre-polymers which are aminated methylpolysilanes are useful for the preparation of fine grained silicon carbide ceramic materials and silicon carbide-containing ceramics. The pre-polymers exhibit ease of handling and their use to obtain silicon carbide ceramic materials results in high yields.

Abstract: Novel, high yielding prepolymers are prepared by reducing chloropolysilanes with lithium aluminum hydride. These prepolymers exhibit good handling properties and are useful for preparing ceramics, silicon carbide ceramic materials and articles containing silicon carbide.

Abstract: What is disclosed is an improved method of preparing silicon carbide which is characterized by the preparation of a specific pre-silicon carbide polymer. The method allows the preparation of silicon carbide from specific polysilane polymers without the cumbersome extractions and purifications found in the newer methods of silicon carbide preparation.

Abstract: Pre-polymers which are substituted with (CH.sub.3).sub.3 SiO-groups are useful for the preparation of fine grained silicon carbide ceramic materials. The pre-polymers exhibit ease of handling and their use to obtain silicon carbide ceramic materials results in high yields.

Abstract: An improved process for producing hexamethyldisilane by reacting ether solutions of methyl Grignard with a crude mixture of chloromethyl disilanes, the improvement which comprises obtaining higher yields and simplified purification of HMDS by the use of a mixed solvent system composed of tetrahydrofuran and the diethyl ether of tetraethylene glycol.

Abstract: Pre-polymers which are alkylated or arylated methylpolysilanes are useful for the preparation of silicon carbide ceramic materials. The pre-polymers exhibit ease of handling and their use to obtain silicon carbide ceramic materials results in high yields.

Abstract: Pre-polymers which are alkoxylated or phenoxylated methylpolysilanes are useful for the preparation of fine grained silicon carbide ceramic materials and silicon carbide-containing ceramics. The pre-polymers exhibit ease of handling and their use to obtain silicon carbide ceramic materials results in high yields.

Abstract: A process of producing tetramethyldisilane by reacting tetramethyldichlorodisilane with a reducing mixture of NaH and NaBH.sub.4 in the presence of a complexing ether such as the diethyl ether of tetraethylene glycol.

Abstract: 1,2 Dichloro-1,1,2,2-tetramethyldisilane is synthesized in high yield and good purity starting from a crude mixture of chloromethyldisilanes formed as by-products in the manufacture of silicones. The new method uses less than half as much Grignard reagent as previous methods required. The synthesis can also be used to produce other haloalkyldisilanes such as chloropentamethyldisilane or 1,1,2 trichloro-1,2,2-trimethyldisilane.

Abstract: Organic polysilanes may be produced in a simpler, safer and more economic manner by reacting an organohalosilicon hydride with lithium metal or lithium-alkali metal alloy. According to the reaction the silicon-silicon bonds of the organopolysilane are formed by the removal of halogen and hydrogen from the hydride. Particularly important is the formation of dodecamethylcyclohexasilane by the reaction of dimethyl chlorosilane with lithium metal. Simpler polysilanes may be produced by adding to the reaction mixture endcappers such as trifunctional organohalosilanes without an Si-H bond.

Abstract: An improved process for producing tetramethyldisilane by Lewis acid catalyzed redistribution of hexamethyldisilane with a crude mixture of methylchlorodisilane which comprises the distillation of the mixed redistributed product with collection of a middle distillate cut containing at least 95% pure tetramethyldichlorodisilane.

Abstract: A phenylmethylpolysilane polymer is prepared by the addition of a small amount of phenylmethyldichlorosilane to dimethyldichlorosilane and reduction of the resulting mixture. The polymer is a gum or meltable resinous material which has utility as a precursor for preparing silicon carbide fibers.

Abstract: Pre-polymers which are alkoxylated or phenoxylated methylpolysilanes are useful for the preparation of fine grained silicon carbide ceramic materials and silicon carbide-containing ceramics. The pre-polymers exhibit ease of handling and their use to obtain silicon carbide ceramic materials results in high yields.