Abstract: The presence of both an organotitanium compound and a microencapsulated platinum-containing hydrosilation catalyst in organosiloxane compositions curable by a hydrosilation reaction not only increases the heat stability of elastomers prepared from the composition, but also unexpectedly increases the cure rate of the compositions. In addition to the platinum-containing and organotitanium co-catalysts the curable compositions comprise an organohydrogenpolysiloxane curing agent and a liquid or high consistency organopolysiloxane containing an average of at least two ethylenically unsaturated hydrocarbon radicals per molecule.

Abstract: The adhesion developed during curing of organosiloxane compositions comprising a polyorganosiloxane containing silicon-bonded alkenyl and fluorinated alkyl radicals, at least one organosiloxane as the curing agent, a platinum-containing hydrosilation catalyst and conventional organosiloxane adhesion promoters is substantially improved when the alkenyl-substituted siloxane units are separated from the closest fluorine-containing siloxane units by at least one dimethylsiloxane unit.

Abstract: An apparatus for preparing foams exhibiting a uniformly small cell size, a minimum number of ruptured cell walls and a smooth surface from foamable curable compositions comprises means to transport the ingredients of a foamable, curable composition to the input of a static mixer in which the ingredients of the composition are blended to homogeneity prior to being extruded into an exit zone and through an exit orifice. The length to diameter ratio of the mixing zone and the diameter of the exit orifice are within specified ranges.

Abstract: The presence in curable, foamable organosiloxane compositions of an organosiloxane containing at least one diphenylsiloxane unit, a triorganosiloxane unit and a silanol group imparts a high expansion ratio, an excellent moldability, and an excellent storage stability, and that is not subject to post-cure whitening.

Abstract: The amount of solvent-extractable materials present in organosiloxane gels cured by a platinum-catalyzed hydrosilylation reaction can be reduced without sacrificing other desirable properties the gels when the curable composition used to prepare the gel comprise a first polydiorganosiloxane with vinyl or other ethylenically unsaturated hydrocarbon radicals only at the terminal positions, a second polydiorganosiloxane with silicon bonded hydrogen atoms only at the terminal positions and a crosslinking reactant containing at least three alkenyl radicals or silicon-bonded hydrogen atoms per molecule. The number of silicon-bonded hydrogen atoms or alkenyl radicals in excess of 2 per molecule of crosslinking reactant constitute from 10 to 30 percent of these reactive groups present in the curable composition.

Abstract: This invention provides a novel class of organohydrogenpolysiloxanes that function as curing agents for organosiloxane compositions curable by a hydrosilylation reaction in addition to imparting excellent adhesion to the cured composition. This invention also provides curable organosiloxane compositions containing these novel organohydrogen-polysiloxanes. The compositions exhibit excellent adhesion to a variety of organic and inorganic substrates, including but not limited to metals, glasses, and plastics.

Abstract: This invention provides novel organosulfonimidates and a method for preparing both the present sulfonimidates and those disclosed in the prior art. Some of the sulfonimidates can be condensed under relatively mild conditions to form polyorganooxothiazenes.

Abstract: Alpha, omega-dihydroxyperfluoroalkylethylmethylpolysiloxanes are prepared by reacting zinc oxide with a perfluoroalkylethylmethyldichlorosilane in an organic solvent, followed by the addition of water and protic acid with stirring to the resulting reaction mixture to generate the silanol group at the molecular chain terminals of the resultant polysiloxane. The advantage of the present method is the negligible yield of the corresponding cyclic polyorganosiloxanes.

Abstract: Silicone grease compositions are prepared by blending a thickening agent with a liquified crosslinked organosiloxane gel produced using a platinum-catalyzed hydrosilylation reaction. The gel is liquified by application of a shearing force to the crosslinked gel. The shearing force can be applied prior to and/or during blending of the gel with the thickener.

Abstract: The specification is concerned with a process and apparatus for continuous manufacture of moisture curable silicone compositions.

Abstract: The electrical conductivity of organosiloxane compositions containing high loadings of finely divided silver particles coated with an esterified fatty acid is superior relative to the conductivity of compositions containing silver particles that are either uncoated or coated with prior art treating agents, including free fatty acids.

Abstract: This invention relates to hollow elongate articles such as tubing and fibers formed from non-crosslinked polyvinyl alcohol. The articles are prepared by extruding a solution of polyvinyl alcohol in the shape of the desired article into a coagulating bath concurrently with a stream of a non-solvent for the polymer. The stream occupies the area corresponding to the interior cavity of the article and prevents collapse of the cavity until the article has solidified in the coagulation bath.

Abstract: A foam forming composition comprises (a) one or more polysiloxanes having not less than three alkylhydrogen siloxane units per molecule, (b) one or more polysiloxanes having not less than two silicon-bonded hydroxyl group per molecule, (c) at least one liquid organic titanium compound and (d) a catalyst. Reaction between the organic titanate (e.g. tetraisopropyltitanate) and the hydroxy functional polysiloxane rapidly increases viscosity of the mixture to restrict flow of the composition as it cures to form a foam within 240 seconds of mixing. A vinyl polysiloxane may be incorporated.

Abstract: The curable organosiloxane compositions of the present invention contain a hydrosilylation catalyst that is microencapsulated within a layer of silicone resin or polysilane resin. These compositions are characterized by the presence of carbon black or a member from a specified group of metal compounds that prevents coagulation in cured materials of the resin portion of the microencapsulated catalyst.

Abstract: The present invention provides microencapsulated hydrosilylation catalysts for one-part heat curable organosiloxane compositions. Compositions containing these exhibit long-term storage stability yet cure rapidly when heated above the melting point of the encapsulating polymer. At least a portion of these microcapsules are less than one micron in diameter, and substantially all are less than about three microns in diameter. Compositions containing the preferred platinum group metals as catalysts are optically transparent.The microencapsulated curing catalysts of this invention are prepared by irradiating with UV light in the wavelength range of from 300 to 400 nanometers a solution containing (1) at least one of a specified group of photocrosslinkable organosiloxane compounds derived from propargyl esters of carboxylic acids containing a terminal aromatic hydrocarbon radical and at least two ethylenically unsaturated carbon atoms and (2) a liquid or solubilized hydrosilylation catalyst.

Abstract: This invention provides polyorganooxothiazenes exhibiting levels of molecular weight and properties not heretofore achieved by similar polymers reported in the prior art. The sulfonimidates that are condensed to form the polymers are prepared using a novel reaction between an N-triorganosilylsulfonamide and a triorganodihalophosphorane to form the corresponding N-triorganosilylsulfonimidoyl halide that is subsequently reacted with a fluorinated alcohol or phenol to form the N-triorgano-silylsulfonimidate.

Abstract: In accordance with the present method for preparing an elastomeric silicone foam, an inert gas is injected under superatmospheric pressure during or after the merging of a silanol-containing organopolysiloxane that is liquid at room temperature an organohydrogenpolysiloxane that is liquid at room temperature, and hydrosilation catalyst, the merging step is followed by mechanical mixing in an enclosed chamber, at which time the mixture is ejected into the atmosphere. Completion of cure with simultaneous evolution of hydrogen occur under atmospheric pressure with the reactive ingredients and the inert gas all present in a homogeneously microdispersed/mixed state. The present method stabilizes the cells formed by the hydrogen and makes possible the development of a large quantity of cells of uniform size and uniform distribution, resulting in a high-expansion ratio foam.

Abstract: The molecular weight of diphenylsiloxane-dimethylsiloxane copolymers can be controlled and the desired copolymers obtained in high yield when mixtures of hexaphenylcyclotrisiloxane and hexamethylcyclotrisiloxane are polymerized in a suitable aprotic solvent using a specified class of lithium silanolates as the polymerization initiator and a low molecular weight silanol-terminated polydiorganosiloxane as a molecular weight regulator, and the polymerization reaction is terminated when from 85 to 100 percent of the cyclosiloxanes are converted to said copolymer and prior to any substantial equilibration of the copolymer.

Abstract: Chemically inert fluorinated organosilicon compounds for use as, e.g., lubricants are described corresponding to the formulaeR.sup.1.sub.4 SiorR.sup.2.sub.3 Si(R.sup.3 SiR.sup.4.sub.2).sub.z R.sup.23,where z is from 1 to 4, inclusive, at least three of the R.sup.1 radicals, at least two of the terminal R.sup.2 radicals, and preferably one of the non-terminal R.sup.2 radicals are derived from(a) monovalent alkyl-terminated fluorotelomers of chlorotrifluoroethylene or(b) monovalent alkyl-terminated fluorocotelomers of chlorotrifluoroethylene and either hexafluoropropene or mixtures of hexafluoropropene and tetrafluoroethylene, andR.sup.3 represents an alkenyl-terminated divalent fluorotelomer or cotelomer, and the value of z is from 1 to 4, inclusive.

Abstract: A foamable silicone composition comprises a polysiloxane having silicon-bonded hydrogen atoms, a polysiloxane having siloxane units including unsaturated groups, a polysiloxane having silicon-bonded hydroxyl groups, a noble metal catalyst and from 3 to 40 parts by weight per 100 parts by weight of the composition of entities of borosilicate or silicate glass or mixtures thereof. The composition comprises first and second Parts A and B having viscosities which are sufficiently similar to each other to permit facile machine mixing of the Parts; the first Part comprises the noble metal catalyst and a portion of the entities and the second Part comprises the polysiloxane having silicon-bonded hydrogen atoms and a portion of the entities pretreated with a compatible silane or a polysiloxane having silicon-bonded hydrogen atoms. Preferred entities comprise hollow spherical particles or hollow entities which have an irregular configuration.