Abstract: Liquid silicone compositions are described that cure to rubber which exhibits a unique combination of properties including low compression set and unprimed adhesion to a variety of substrates. The compositions include silicone polymers curable by hydrosilation reaction and specific combinations of adhesion promoting materials. Compositions containing aluminum chelates and epoxytrialkoxysilanes have been found particularly useful when adhesion to metal substrates is desired. When the compositions are desired to adhere to plastic materials, it is advantageous to include along with the aluminum chelate and epoxytrialkoxysilane, a tetraalkyltitanate, an alkylpolysilicate, and an acrylate or methacrylate compound.

Abstract: A method of making silethynyl polymers having units of the general formula --(R.sub.2 SiC.tbd.C)-- wherein each R independently denotes a hydrogen atom, an alkyl, aryl or alkenyl group or a substituted alkyl, aryl or alkenyl group having up to 18 carbon atoms comprises adding a lithium salt of one or more diethynylsilanes of the general formula R.sub.2 Si(C.tbd.CH).sub.2 to one or more dihalosilanes of the general formula R.sub.2 SiX.sub.2 where X is a halogen atom and allowing the components to react. Copolymers with alternating units can be made. Linear polymers are made preferentially. Limiting the use of solvent increases the percentage of linear polymers produced.

Abstract: A process is provided for the preparation of expanding-contracting hydrogel composites which process comprises the steps of adding solid particles of a polyelectrolyte to a polyvinyl alcohol solution and subjecting the mixture to a low temperature treatment to cause gelation of the polyvinyl alcohol with the polyelectrolyte dispersed as a heterogeneous phase (i.e. solid particles) within the polyvinyl alcohol gel. Hydrogel composites made by the process exhibit high strength and a capacity to expand and contract over a wide range with changes in environment.

Abstract: The elastic modulus and density of an amorphous, ceramic article derived from a resinous organosilicon polymer and having a composition consisting essentially of silicon, nitrogen and/or carbon are increased while substantially maintaining or improving tensile strength by heat treating the ceramic article at an elevated temperature under superatmospheric nitrogen pressure to increase its density while avoiding crystallization. During heat treatment, at least some of the conditions of time, temperature, heating rate, cooling rate, pressure and atmosphere are controlled to minimize erosion of the article which could otherwise occur due to the loss to the surrounding atmosphere, as a gas or gaseous component, of at least one of nitrogen, silicon and carbon. The heat treated, ceramic article is amorphous and non-crystalline and has a density substantially greater than 2.5 g/cc together with desirable values of tensile strength and elastic modulus.

Abstract: A polymeric material which exhibits nonlinear optical properties if undoped and conductive properties if doped. The polymer is prepared by polymerizing diethynylsilane compositions, the resulting polymeric material having a weight average molecular weight between about 20,000 and about 200,000 grams per mole. The polymer is prepared and catalytically polymerized by exposure to a catalyst, such as MoCl.sub.5 or W(CO).sub.6 /hv.

Abstract: A method is disclosed for the preparation of ceramic materials or articles by the pyrolysis of preceramic polysilanes wherein the preceramic polysilanes are rendered infusible prior to pyrolysis by exposure to ultraviolet irradiation in the presence of a reactive gas selected from the group consisting of ethylene, 1,3-butadiene, 2-methyl-1,3-butadiene, 1,4-pentadiene, silane, chlorosilane, dichlorosilane, boron trichloride, oxygen and water mixture, acetylene, and tetravinylsilane. This method is especially suited for the preparation of ceramic fibers. The ceramic fiber's surface properties can be modified by the practice of this invention; for example, a ceramic fiber with a carbon rich surface layer can be obtained when 1,3-butadiene is used as the reactive gas.

Abstract: The invention relates to the chemical vapor deposition of dihalogenated silanes to form stable, abrasion resistant, photoconductive, dopable semiconductor amorphous films on substrates. Additional hydrogen and plasma discharge conditions are not necessary to practice the invention.

Abstract: This invention discloses a method of treating silicon with non-volatile, phosphorous compounds to allow the silicon to be used in the direct process for the manufacture of alkylhalosilanes. The treatment of the silicon is carried out by feeding phosphorous compounds to the silicon during or after refining.

Abstract: The invention is a method of forming a continuous coating of amorphous silicon carbide on the surface of articles by plasma enhanced chemical vapor deposition. In the method, the chemical vapor comprises a silicon-containing cyclobutane, such as a silacyclobutane or a 1,3-disilacyclobutane. The coatings formed by the invention are useful for application to solar cells, for preventing corrosion of electronic devices, for forming interlevel dielectric layers between metallization layers of electronic devices, and for providing abrasion resistance to surfaces.

Abstract: Alkylpoly(polysilyl)azanes are prepared by the reaction of chlorine-containing polysilane preceramic polymers and various disilazanes. The alkylpoly(polysily)azanes may be converted to ceramic materials by pyrolysis at elevated temperatures.

Abstract: A process for the preparation of more highly alkylated silanes and disilanes. The process comprises (A) contacting a halodisilane, with an alkyl halide in the presence of a metal, such as aluminum, which serves as a halogen acceptor, (B) reacting the halodisilane with the alkyl halide in the presence of the metal at a temperature greater than about 150.degree. C. to form the more highly alkylated silanes and disilanes and a metal halide; and (C) isolating and separating the more highly alkylated silanes and disilanes.

Abstract: This invention discloses a method of treating silicon with non-volatile, phosphorous compounds to allow the silicon to be used in the direct process for the manufacture of alkylhalosilanes. The treatment of the silicon is carried out by feeding phosphorous compounds to the silicon during or after refining.

Abstract: A process for the preparation of more highly alkylated silanes. The process comprises (A) contacting a halide of silicon, a silane or a disilane, with an alkyl halide in the presence of a metal, such as aluminum, which serves as a halogen acceptor, and a sufficient quantity of a catalyst effective in improving exchange of alkyl groups from the alkyl halide with said halogen atoms of the halide of silicon; (B) reacting the halide of silicon with the alkyl halide in the presence of the metal and the catalyst at a temperature greater than about 150.degree. C. to form the more highly alkylated silanes and a metal halide; and (C) isolating and separating the more highly alkylated silanes.

Abstract: A process for preparation of an alkyl halide, RX, from reaction between the corresponding alcohol, ROH, and a hydrogen halide, HX, which improves conversion of the hydrogen halide to the alkyl halide in a single pass through a reactor. The process comprises (A) contacting and reacting the hydrogen halide with a stoichiometric excess of the alcohol in a plug-flow reactor in which flow of a mixture comprising unreacted alcohol, unreacted hydrogen halide, the alkyl halide, and water is co-current; and (B) isolating and separating the alkyl halide.

Abstract: Polysilacyclobutasilazanes are reacted with chlorosilanes and/or chlorodisilanes and ammonia to provide silane-modified polysilacyclobutasilazanes having silacycles incorporated in the polymer, which silacycles are subsequently used to cross-link the silazanes.

Abstract: The preparation of highly densified ceramic bodies by the sintering of certain organopolysiloxanes filled with silicon carbide powders, and metal-containing sintering aids is described. Such highly densified ceramic bodies can be prepared by either a pressureless sintering process or a hot press sintering process. The compositions of this invention can be formed into desired shapes and then sintered to form ceramic, shaped bodies with high densities. One advantage of the present invention is that the green bodies have relative high strengths and thus can be easily handles and, if desired, machined before sintered. The organopolysiloxanes useful in this invention must yield a ceramic char which contains free or excess carbon in addition to carbon in the form of silicon carbide upon pyrolysis to elevated temperatures.

Abstract: What is disclosed are food compositions which contain a polyorganosiloxane fluid as a fat substitute and an anti-anal leakage agent. The anti-anal leakage agents comprise C.sup.12 -C.sub.24 essentially saturated fatty acids or edible, digestible sources thereof; non-degradable, water insoluble fibers of plant origin; and silica.

Abstract: Polysilacyclobutasilazanes are reacted with chlorosilanes and/or chlorodisilanes and ammonia to provide silane-modified polysilacyclobutasilazanes having silacycles incorporated in the polymer, which silacycles are subsequently used to cross-link the silazanes.

Abstract: A method for analyzing and quantifying the individual trace metals content of a semiconductor material in the low to sub-parts per billion (ppba) range. The method comprises (A) float-zone refining of a sample of the semiconductor material creating a melt zone containing essentially all the trace metals of the sample; (B) cooling the melt zone to form a solid zone concentrated in trace metals; (C) separating the solid zone concentrated in trace metals from the sample of the semiconductor material; (D) converting the solid zone concentrated in trace metals into a form suitable for trace metals analysis; (E) analyzing the solid zone with known trace metals analytical techniques; and (F) calculating total trace metals from these analytical results. This method can also be applied to the small tip which forms on the side of the solid zone.

Abstract: This invention relates to materials produced by diluting in a solvent a platinum or rhodium catalyzed 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.