Abstract: The invention relates to aliphatically unsaturated organosilicon compounds having 2 to 17 silicon atoms, to processes for their preparation and to their use in crosslinkable organopolysiloxane compositions, especially in compositions which can be crosslinked peroxidically or by hydrosilylation.

Abstract: The invention relates to aliphatically unsaturated organosilicon compounds having 2 to 17 silicon atoms, to processes for their preparation and to their use in crosslinkable organopolysiloxane compositions, especially in compositions which can be crosslinked peroxidically or by hydrosilylation.

Abstract: The present invention relates to organopolysiloxane resin solutions which contain 1-alkenes and are free from aromatic hydrocarbons, processes for their preparation and their use in organopolysiloxane compositions from which it is possible to produce coatings which repel tacky substances.

Abstract: Organopolysiloxane resin powders having a mean particle diameter (median value d.sub.50,3) of from 70 to 300 .mu.m and a proportion of resin particles having a diameter <45 .mu.m of less than 5 percent by weight, based on the total weight of the organopolysiloxane resin powder.

Abstract: Coating compositions based on water-redispersible powders comprising water-soluble polymer and organosilicon compounds, wherein the organosilicon compounds comprise at least one low molecular weight organosilicon compound having a viscosity of not more than 5,000 mm.sup.2 /s at 25.degree. C. and at least one high molecular weight organopolysiloxane resin which has a viscosity of at least 100,000 mm.sup.2 /s at 25.degree. C. or is solid at room temperature.

Abstract: Methylchlorosilanes are prepared from silicon and methyl chloride in the presence of a copper catalyst and optionally promoter substances, the production rates of the individual methylchlorosilanes, based on the surface area of the silicon employed, being controlled by the structural parameter QF of the silicon. The structural parameter QF is determined by(a) cutting up silicon test specimens to form a cut surface.(b) totaling on the cut surface the areas of the precipitates of intermetallic phases having a longitudinal shape to give an area number A,(c) totaling on the cut surface the areas of precipitates of intermetallic phases having a circular shape to give an area number B, and(d) obtaining the quotient of the area number A and the area number B, called the structural parameter QF.

Abstract: The present invention relates to a process for preparing coating compositions which comprises condensing a mixture containing (A) at least one silicone resin containing Si-bonded alkoxy groups and, if desired, silanol groups and/or at least one silane and/or siloxane which contains Si-bonded alkoxy groups and, if desired, silanol groups to form a silicone resin, (B) a basic condensation catalyst in an amount sufficient to render this mixture basic, (C) optionally water and (D) optionally an organic solvent.The resultant coating compositions are preferably employed in the form of a solution, emulsion or dispersion.

Abstract: Organosols of organopolysiloxanes are prepared by adding water-soluble organic solvents or mixtures thereof or water-soluble mixtures of water-soluble and water-insoluble organic solvents to aqueous, colloidal suspensions of organopolysiloxanes obtained by adding at least one alkoxysilane and/or the partial hydrolyzate thereof, and, if appropriate, mixed with an organo(poly)siloxane free of alkoxy groups and having a maximum of 8 siloxane units per molecule, to water in the presence of emulsifiers at a maximum rate of 5 moles of organosilicon compound per hour and per liter of water, and subsequently removing the water by distillation.

Abstract: The invention relates to compounds of the formula[RSiO.sub.3/2 ].sub.z (I)in whichz is 6, 8 or 10;R represents the same or different radicals of the formulas--CH.sub.2 CH.sub.2 --X (II), --CH(CH.sub.3)--X (III) or --O--Si(R'.sub.2)--Y (IV)with the proviso that up to z-1 of the radicals can also be radicals of the formula --O--SiR'.sub.3, in which X represents a monovalent radical or one half of a divalent radical of the formulas ##STR1## R' represents the same or different C.sub.1 - to C.sub.6 -alkyl, C.sub.1 - to C.sub.6 -alkoxy or phenyl radicals;R" represents the same or different C.sub.1 - to C.sub.18 -alkyl radicals, which can be substituted by radicals of formulas (V) or (VI);R'" represents the same or different divalent C.sub.1 - to C.sub.18 -hydrocarbon radicals, preferably alkylene and/or phenylene radicals and/or radicals of the formula--(R'.sub.2 SiO).sub.n --;Z represents a halogen atom or an N-bonded amino radical, that is an NH.sub.

Abstract: The invention relates to a process for preparing highly porous glass-ceramic molded parts having carbon atoms linked to silicon atoms, which comprises reacting a molded part, containing an organopolysiloxane which is solid at room temperature, and consists of units of the formula ##STR1## where R is a radical selected from the formulas ##STR2## and is linked via a single silicon-silicon bonded, in a non-oxidizing atmosphere or in vacuo at temperatures ranging from 700.degree. to 1300.degree. C.

Abstract: The invention relates to heat-vulcanizable compositions containing an organopolysiloxane and from 0.01 to 10 parts by weight of an organo(poly)silane per 100 parts by weight of organopolysiloxane.

Abstract: Silicone resin powders are obtained by spray drying aqueous colloidal suspensions of organopolysiloxanes which are prepared by adding an alkoxysilane and/or a partial hydrolysate thereof and, if appropriate, mixed with an organo(poly)siloxane which is free of alkoxy groups and contains a maximum of 8 siloxane units per molecule, to water in the presence of an emulsifier at a maximum rate of 5 moles of organosilicon compound per hour per liter of water.

Abstract: Substrates which are exposed to weathering are coated with paints containing an epoxy resin and a silicon compound containing basic nitrogen which is bonded to the silicon via a carbon and which has at least one hydrogen atom bonded directly to the nitrogen atom.

Abstract: Colloidal suspensions of organopolysiloxanes are prepared by mixing an organosilicon compound selected from the group consisting of mixtures of alkoxysilanes and/or partial hydrolysates thereof and an organo(poly)siloxane which is optionally free of alkoxy groups and contains a maximum of 8 siloxane units, which is mixed with at least one alkoxysilane and/or a partial hydrolysate thereof, with water in the presence of an emulsifier, at a maximum rate of 5 moles of organosilicon compound per hour per liter of water, in which the organosilicon compound and the water is fed continuously, but separately from one another, into a reactor, in which at least one of the two substances contains an emulsifier, while the alkanol is being continuously removed by distillation from the aqueous suspension continuously emerging from the reactor. The aqueous suspension from which the alkanol has been removed by distillation is, if desired, recycled back into the reactor.

Abstract: The invention relates to a process for preparing moldings based on silicon oxycarbide, which comprises reacting a molding containing from 50 to 90 percent by weight of silicon oxycarbide having an average particle size of from 0.5 to 50 um with from 10 to 50 percent by weight of a silicone resin having the general formula[(CH.sub.3 SiO).sub.x (OR).sub.y (OH).sub.z ].sub.n,in which R is an alkyl radical having from 1 to 4 carbon atoms, x is in the range of from 1.4 to 1.5, y is in the range of from 0 to 0.08, z is in the range of from 0 to 0.08 and n is in the range of from 20 to 40, under a nonoxidizing atmosphere or in a vacuum at temperatures in the range of from 700.degree. to 1500.degree. C.

Abstract: A process for preparing silicon carbide fibers, which comprises spinning a copolymer obtained by reacting at least one disilane of the formulaR.sub.2 R.sup.1 Si.sub.2 (OCH.sub.3).sub.3in which R represents the same or different alkyl, alkenyl or aryl radicals and R.sup.1 represents the same or different alkyl radicals, which may optionally be mixed with a compound of the formulaR.sub.2 Si.sub.2 (OCH.sub.3).sub.4in which R is the same as above, with at least one compound of the formulaR.sub.2 R.sup.2 SiHin which R is the same as above and R.sup.2 represents a methoxy radical or is the same as R, in the presence of at least one compound of the formulaMORin which R is the same as above and M represents an alkali metal, and a compound of the formulaHO--(R.sup.1 R.sup.3 SiO).sub.x (R.sub.2.sup.1 SiO).sub.y --.sub.n Hin which R.sup.1 is the same as above, R.sup.3 represents the same or different alkenyl radicals, x is in the range of from 0.5 to 1.

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: Hydrophobic fibers are prepared by treating fibers with a composition containing an organopolysiloxane having Si-bonded hydrogen atoms as essentially its only reactive group, and a platinum catalyst which is inhibited by a compound which is volatile under the conditions at which the organopolysiloxane containing Si-bonded hydrogen atoms is deposited on the fiber.

Abstract: A process for preparing a solid object which comprises molding a composition obtained from the reaction of polysiloxanes having at least 3 silicon atoms per molecule and containing SiOC-bonded organic radicals and optionally, SiC-bonded organic radicals, with boric acid anhydride, and thereafter exposing the molded object to moisture.

Abstract: A process for preparing organopolysiloxanes having SiC-bonded organofunctional groups, which comprises reacting an organopolysiloxane containing SiC-bonded hydroxyl and/or alkoxy groups and having an average of about 0.85 to 1.8 SiC-bonded monovalent hydrocarbon radicals or halogenated monovalent hydrocarbon radicals for each Si atom, with an organosilicon compound containing alkoxy groups and/or siloxane oxygen groups and at least one SiC-bonded organofunctional radical per molecule in the presence of an organic solvent and a basic catalyst.The resultant organopolysiloxanes having SiC-bonded organofunctional groups may, for example, be used for preparing modified polymers by copolymerizing the organopolysiloxanes with a monomer containing an aliphatic double bond, such as styrene or hydroxyethyl methacrylate, or by reacting the organopolysiloxanes with an additional polymer such as an epoxy resin.