Abstract: Azlactone functional silicon containing compounds are prepared from alkenyl azlactones and SiH containing compounds in a hydrosilation reaction. The resulting compounds can be reacted with nucleophilic compounds to provide amidoacyl group containing silicon compounds. When the amidoacyl group containing silicon compounds contain ethylenic unsaturated they can be polymerized to provide polymeric networks useful as pressure sensitive adhesives release compositions, or elastomeric materials.

Abstract: Novel polysiloxane-silazane preceramic polymer compositions are prepared by the controlled hydrolysis polymerization of a trimer or tetramer of a monomer of the structure ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are independently alkyl groups containing from 1 to 4 carbon atoms, R.sup.a, R.sup.b, R.sup.c, and R.sup.d are independently alkenyl or alkyl groups containing from 2 to 6 carbon atoms with the proviso that at least one of R.sup.a, R.sup.b, R.sup.c, or R.sup.d group is an alkenyl group. The polysiloxane-silazane polymers are cured by heat and optionally free radical initiators such as various peroxides. The cured preceramic polymers so formed can be u sed in the pyrolyzed or non-pyrolyzed state as adhesives, coatings, binders, fibers, matrix resins, and the like.

Abstract: The emulsion polymerization of a mixture of organic silicon monomers and vinyl containing organic monomer is effected substantially concurrently. Flocculation of the emulsion polymerized material, and recovery of the flocculated material has been found useful in providing multi-lobed impact modifiers for a variety of organic thermoplastic polymers.

Abstract: Radiation polymerizable acrylate- or methacrylate-functional organo-polysiloxanes having the structural formula ##STR1## wherein R is a radical selected from the group consisting of monovalent hydrocarbon radicals having from 1 to 20 carbon atoms, substituted monovalent hydrocarbon radicals having from 1 to 20 carbon atoms, monovalent hydrocarbonoxy radicals having from 1 to 20 carbon atoms and a radical of the formula: ##STR2## in which at least one R is a radical of formula (I), R.sup.1 is hydrogen or a methyl radical, R.sup.2 is selected from the group consisting of a multivalent hydrocarbonoxy radical and a multivalent hydrocarbonoxy radical containing non-terminal atoms selected from the group consisting of oxygen, sulphur and nitrogen atoms, R.sup.3 is a divalent hydrocarbon radical or a divalent hydrocarbonoxy radical, a is a number having an average value of from 0.7 to 2.6, b is a number of from 1 to 5, and x is a number from 2 to 1000.

Abstract: A composition which is curable to an elastomer comprising:A polymer or mixture of polymers of the formula ##STR1## wherein: X are monovalent moieties having ethylenic unsaturation which can be the same or different;Y are divalent linking groups which can be the same or different;m is an integer of 0 to 1;D are monovalent moieties which can be the same or different selected from the group consisting of hydrogen, an alkyl group of 1 to about 10 carbon atoms, aryl, and substituted aryl;R are divalent hydrocarbon groups which can be the same or different;R.sup.1 are monovalent moieties which can be the same or different selected from the group consisting of alkyl, substituted alkyl, aryl, and substituted aryl;R.sup.2 are monovalent moieties which can be the same or different selected from the group consisting of alkyl, substituted alkyl, aryl, and substituted aryl;R.sup.

Abstract: There is provided an organopolysiloxane composition having low compression set as well as fuel and oil resistance in addition to high strength, good elongation, and tear comprising:(A) 100 parts of a first component comprising:(1) a vinyl-containing liquid organopolysiloxane or a blend of vinyl-containing liquid polysiloxanes;(2) optionally, filler; and(3) a catalyst; and(B) from 1 to 100 parts, based on 100 parts of (A), of a hydrogen silicone composition selected from the class consisting of hydrogen containing silanes and hydrogen containing polysiloxanes and mixtures of hydrogen containing polysiloxanes with fillers and high viscosity polysiloxanes;(C) optionally, magnesium oxide to impart oil resistance;(D) optionally, an MQ resin to impart fuel resistance; and(E) optionally, a cerium containing compound or, alternatively, tetramethyldivinyldisilazane to impart low compression set.

Abstract: A group of substituted benzotriazoles unexpectedly improves the physical properties, particularly the tensile strength and tear strength, of peroxide cured organosiloxne elastomers.

Abstract: A process is described for the preparation of modified polysiloxanes by reaction of polyvinylsiloxanes with compounds of the formula ##STR1## in which R is H, CH.sub.3 or C.sub.2 H.sub.5, in which at least one radical R is H, and R.sub.f is a perfluoroalkyl radical having 8 to 16 C atoms, in about equivalent amounts, relative to the vinyl groups, at elevated temperature. In addition, the polysiloxanes prepared in this manner are protected. Equally, the use of these polysiloxanes for the oil- and water-repellent treatment of fiber materials is claimed. This treatment makes it possible to achieve very good wash- and cleaning-resistant oil- and water-repellency, using small amounts of fluorine.

Abstract: A material for forming a high purity thin film which includes a silicone ladder polymer dissolved in an organic solvent is applied to a substrate to form a thin film thereon. The thin film is then heated, thereby removing the solvent and simultaneously curing the thin film. Subsequently, the cured thin film is exposed to an oxygen plasma to form a high purity SiO.sub.2 thin film on the substrate. Although the method consists of simple processes and employs low treatment temperatures, it is capable of forming a high purity SiO.sub.2 thin film which exhibits excellent step coverage and high dielectric breakdown strength.

Abstract: A silicone rubber composition which comprises an organopolysiloxane, a finely divided silica filler, and optionally an organosilicon compound having at least one .tbd.SiH bond in the molecule is described. When an organic peroxide of the following general formula ##STR1## wherein n is an integer of from 2 to 8, and R.sup.2 and R.sup.3 are independently a monovalent hydrocarbon group having from 3 to 10 carbon atoms or a group of the formula, Si(R.sup.4).sub.3, wherein R.sup.4 represents a group selected from a methyl group, an ethyl group and a phenyl group, is added, surface tackiness and physical properties are remarkably improved.

Abstract: Disclosed is an automotive coating composition comprising (i) a basal resin which is either (a) a copolymer containing a specific polysiloxane macromonomer having two or more functional groups selected from the class consisting of hydroxyl and alkoxy groups per molecule and a number average molecular weight of 400 to 100,000 and an oxirane group-containing vinyl monomer as comonomer units or (b) a mixture of a polymer (I) containing said polysiloxane macromonomer as an essential monomer unit and a polymer (II) containing an oxirane group-containing vinyl monomer as an essential monomer unit and (ii) a chelate compound selected from the class consisting of aluminum chelate compounds, titanium chelate compounds and zirconium chelate compounds.

Abstract: A composition cureable to a solid crosslinked polyorganosiloxane comprises:a) a norbornene functional silicone prepolymer having a plurality of groups of the formula: ##STR1## bound to silicone atoms thereof, where R is H or methyl, R.sup.1 is a direct bond of --C(.dbd.O)O-- and R.sup.4 is ethylene, ethenylene, propylene or propenylene,b) a coreactive silicone prepolymer selected from SiH functional silicones, and alkylthiol functional silicones, said polyorganosiloxanes (a) and (b) being present in an equivalent ratio of between 2:1 and 1:2 norbornene to silicon hydride or alkyl thiol groups, andc) an effective amount of a hydrosilation or thiol-ene cure catalyst, respectively.

Abstract: In a heat curable silicone rubber composition comprising a polydiorganosiloxane base polymer and a curing catalyst, the improvement comprising an effective amount of co-curing agent. Preferably, the co-curing agent has the general formula ##STR1## where R is H or a C.sub.1-5 alkyl radical, R.sup.1 is a C.sub.1-5 alkylene radical, each R.sup.2 is independently selected from H and CH.sub.3, R.sup.3 is H or CH.sub.3, n equals 0 or 1, and m is an integer from 3 to 6, inclusive.

Abstract: A method of preparing vinyl-silicone copolymers which involves the use of a mercapto-functional silicone compound as a macromolecular chain transfer agent. Release coatings and low adhesion backsizes comprising the vinyl-silicone copolymers.

Abstract: A composition that comprises a poly(thio)ureasilazane having at least one alkenyl or alkynyl group and a free radical generator can be crosslinked by an energy input provided in the form of heat, ultraviolet radiation, or an electron beam. The crosslinked poly(thio)ureasilazane compositions can be pyrolyzed to form silicon nitride-containing ceramics.

Abstract: UV curable compositions suitable for use as potting and encapsulating compounds for electrical and electronic devices are provided. The compositions comprise: (a) a UV curable compound polymerizable by a free radical process and containing reactive unsaturated groups, (b) a polysilane photoinitiator, and (c) a peroxide photoinitiator. The use of the two photoinitiators enables one to get a more complete cure, both at the surface and deep into the coating.

Abstract: This invention relates to sulfur containing organopolysiloxane waxes containing(1) at least three mole percent of siloxane units of the formula ##STR1## (2) at least one mole percent of siloxane units selected from the formulas ##STR2## (3) and from 0 to 96 mole percent of siloxane units have the formula ##EQU1## where R is a monovalent hydrocarbon radical having from 1 to 10 carbon atoms, R.sup.1 is an alkyl radical linked to silicon having an average of at least 25 carbon atoms, R.sup.2 is a multivalent radical selected from a hydrocarbon radical having from 2 to 10 carbon atoms which is free of aliphatic unsaturation, a hydrocarbon ether or a hydrocarbon thioether, a is an integer of from 0 to 2, b is an integer of 1 or 2, c is an integer of 1 or 2, d is an integer of from 0 to 2, e is an integer of from 0 to 3, and the sum of a+b is 1, 2 or 3, and the sum of c+d is 1, 2 or 3.

Abstract: Compositions containing an acrylamide functional polydiorganosiloxane, a polydiorganosiloxane having methacryloxyalkyl functionality and silicon-bonded alkoxy functionality, a photoinitiator, and an organic titanate can be improved by using organic peroxides. The improvements are observed in shelf life and pot life of the uncurd composition, and the odor of the cured product. The resulting composition has ternary cure mechanisms with two of these mechanisms being available as shadow cure mechanisms, i.e. cures in areas not exposed to ultraviolet radiation by either exposure to atmospheric moisture or by heating.

Abstract: Organopolysiloxane compositions which can be cured to form elastomers and contain:(a) An organopolysiloxane containing Si-bonded vinyl groups;(b) an organopolysiloxane containing Si-bonded hydrogen;(c) a platinum catalyst which promotes the addition of Si-bonded hydrogen to vinyl groups;(d) an inhibitor which delays the addition reaction of Si-bonded hydrogen with vinyl groups at room temperature, with the proviso that inhibitors containing a hydroperoxy radical are excluded; and(e) an organic peroxide, with the proviso that acyl peroxides are excluded;are used as adhesives.These adhesives are used to bond similar or dissimilar organopolysiloxane elastomers to each other and to bond organopolysiloxane elastomers to optionally primed substrates.

Abstract: A silicone composition adapted for impregnation of electronic parts comprising a vinyl group-containing organopolysiloxane, an organopolysiloxane having at least two hydrogen atoms bonded to silicon atoms in one molecule and a peroxide compound. The peroxide compound is soluble in both organopolysiloxanes and is contained in an amount of from 0.1 to 10 parts by weight per 100 parts by weight of the total of the organopolysiloxanes. The composition has a viscosity which is sufficient to allow easy impregnation, and is in the range of from 20 to 400 centistokes at 25.degree. C.

Abstract: The fluorine-substituted organopolysiloxane as the principal ingredient of the inventive silicone rubber composition has vinyl groups to serve as the cross-linking points at the molecular chain terminals while at least the penultimate siloxane unit or the silicon atom adjacent to the terminal silicon atom has no fluorine-substituted hydrocarbon group bonded to the silicon atom. Being freed from the steric hindrance due to the bulky fluorine-substituted hydrocarbon group bonded to the adjacent silicon atom, the vinyl group bonded to the terminal silicon atom can pertain to the cross-linking reaction much easier than otherwise so that the silicone rubber composition of the invention containing an organic peroxide or a combination of an organohydrogenpolysiloxane and a platinum catalyst as a curing agent can be rapidly cured to give a cured silicone rubber article having excellent resistance against oils and organic solvents as well as mechanical properties.

Abstract: The invention provides a foamable silicon rubber composition capable of giving a foamed and cured silicone rubber body which exhibits, different from conventional foamed silicone rubbers, a retarded and controlled rate of elastic recoverty from a compressed state when the compressive force is released so as to be useful for certain applications. This unique characteristic of the foamed silicon rubber can be obtained by formulating the composition, besides conventional ingredients, a low molecular-weight organopolysiloxane represented by the general formula HO--(--SiR.sup.1.sub.2 --O--).sub.m --(--SiMe.sub.2 --O--).sub.n --H, in which Me is a methyl group, R.sup.1 is an unsubstituted or substituted monovalent hydrocarbon group, at least one of the groups denoted by R.sup.1 in each of the units of the formula --SiR.sup.1.sub.

Abstract: The invention proposes use of ammonia water in place of a conventional caustic alkali or amine compound as a catalyst in the siloxane rearrangement reaction for the preparation of a silicone-based pressure-sensitive adhesive between a poly(diorganosiloxane) having a linear molecular structure and another organopolysiloxane composed mainly of the monofunctional organosiloxane units and tetrafunctional siloxane units. The ammonia water after completion of the reaction can be easily and completely removed by distillation so that the resultant adhesive product is free from any alkaline residue of the catalyst to be imparted with greatly improved stability against viscosity changes and excellent electrical properties along with high reproducibility of the product quality.

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: The presence of a vinyl-specific peroxide in liquid organosiloxane compositions curable to elastomers by a platinum-catalyzed hydrosiliation reaction imparts excellent recovery properties to the elastomers without requiring post-curing. To avoid premature curing the compositions are preferably stored and transported in at least two parts, where the organohydrogensiloxane curing agent and the hydrosilation catalyst are located in different parts of the composition.

Abstract: An extrusion molding silicon rubber composition including (A) 100 pbw of an organopolysiloxane, (B) 5-500 pbw of finely divided silica filler, (C) 1-50 pbw of powder boron nitride having a mean particle size of up to 20 .mu.m, and (D) a curing catalyst is extrusion molded and cured into an insulating article which has improved physical properties and dielectric strength and is thus suitable as electrical insulation.

Abstract: A curable polyorganosiloxane composition is disclosed, comprising: (A) 100 parts by weight of polyorganosiloxane having at least two hydroxyl groups or hydrolyzable groups bonded to a silicon atom in the molecule thereof and having a viscosity at 25.degree. C. of 10 to 1,000,000 cSt, (B) 0 to 2,000 parts by weight of polyorganosiloxane having at least two alkenyl groups bonded to a silicon atom in the molecule thereof and having a viscosity at 25.degree. C. of 10 to 1,000,000 cSt, (C) 0.5 to 20 parts by weight of an organosilicon compound having more than 2 (on the average) hydrolyzable groups bonded to a silicon atom in the molecule thereof, (D) 0 to 10 parts by weight of a catalyst for a condensation reaction, and (E) 0.1 to 5 parts by weight of an organic peroxide, wherein at least 0.01 mol % of all organic groups bonded to a silicon atom as contained in (A) to (C) is an alkenyl group. The composition has both condensation reaction curability and ultraviolet ray curability.

Abstract: Dioxolane-substituted silicon compounds are prepared by a hydrosilylation reaction between a silicon hydride and an aliphatically unsaturated dioxolane compound. The dioxolane-substituted silicon compounds are thereafter converted to diol-substituted silicon compounds and then to diacrylate-substituted silicon compounds. The latter are useful in a curable coating composition for providing a substrate with an adhesive-releasing coating.

Abstract: A copolymer of sulfur dioxide and polyalkylpolysilylstyrene composed of repeating units of formula I: ##STR1## where R is a lower alkyl group, p is an integer between 2 and 5, q in an integer between 1 and 10 representing the sequence length of polyalkylpolysilylstyrene, and n is a number between 5 and 10,000, and having a number-average molecular weight of 2,000 to 2,000,000. This copolymer is a novel and useful positive resist material which is highly sensitive to light, or electron-beam or X-ray radiation and is of high dry etching resistance.

Abstract: A process for preparing moldings or coatings by compression molding, transfer molding or injection molding from materials which contain free-radical generators and an organopolysiloxane which can be crosslinked to form organopolysiloxane elastomers, in which the free-radical generators comprise at least one free-radical generator having a half-life in benzene of 1 minute at 60.degree. C. to 149.degree. C. and at least one free-radical generator having a half-life in benzene of 1 minute at 150.degree. C. to 200.degree. C. Other materials which may be molded are those which can be crosslinked by the addition reaction of Si-bonded hydrogen with SiC-bonded vinyl groups and also contain at least one free-radical generator.

Abstract: Novel heat-resistant maleimido polymers, well adopted for the production of molded/laminated shaped articles, are copolymerizates of (a) a hydrocarbyl N,N'-bis(maleimide); (b) an N,N'-bis(maleimide) containing a diorganopolysiloxane bridge; (c) a diprimary diamine; optionally, (d) at least one other comonomer copolymerizable therewith; and, optionally, (e) a catalyst therefor.

Abstract: Novel heat-resistant maleimido polymers, well adopted for the production of molded/laminated shaped articles, are copolymerizates of (a) a hydrocarbyl N,N'-bis(maleimide); (b) a diamine containing a diorganopolysiloxane bridge; optionally, (c) an N,N'-bis(maleimide) containing a diorganopolysiloxane bridge; optionally, (d) at least one other comonomer copolymerizable therewith; and, optionally, (e) a catalyst therefor.

Abstract: A self-adhering silicone composition comprising;(A) 100 parts by weight of an organopolysiloxane(B) 0.01 to 10 parts by weight of an organic peroxide represented by the formula (II): ##STR1## wherein R.sup.2 represents a hydrogen atom, an alkyl group or alkoxy group having 1 to 10 carbon atoms; R.sup.3 represents an alkyl group having 1 to 10 carbon atoms or a phenyl group; a is an integer of 1 to 3 and b is an integer of 0 to 2, provided that a+b=3; and c is an integer of 1 to 3 and d is an integer of 0 to 2, provided that 1.ltoreq.c+d.ltoreq.5.This composition can bring about strong and durable adhesion to substrates without use of any primers.

Abstract: Whereas the mechanism for the crosslink formation in the curable organopolysiloxane composition of the invention is the ultraviolet-induced addition reaction between alkenyl, e.g., vinyl, groups in a diorganopolysiloxane and mercaptoalkyl groups in another organopolysiloxane as in conventional compositions, the mercaptoalkyl-containing organopolysiloxane used in the invention is, differently from those in conventional compositions, an organopolysiloxane of a three-dimensionally branched molecular structure as composed of the siloxane units of the formulas R.sup.1.sub.3 SiO.sub.0.5, R.sup.1.sub.a (HSR.sup.2)SiO.sub.(3-a)/2 and SiO.sub.2, in which R.sup.1 is, for example, a methyl or phenyl group, R.sup.2 is, for example, --CH.sub.2 CH.sub.2 CH.sub.2 -- and a is zero, 1 or 2, in a specified proportion. In addition, the vinyl group-containing siloxane units in the vinyl-containing diorganopolysiloxane are localized in the molecular structure forming two blocks each bonded to one of the terminal silicon atoms.

Abstract: Crosslinking polysilastyrene by mixing polysilastyrene with 2-15 weight % dicumyl peroxide and heating at 80.degree. C. to 500.degree. C. for 5 minutes to 5 days to produce crosslinking.

Abstract: A composition which is curable to an elastomer comprising (1) a siloxane gum having a Williams plasticity of at least 100 mm/100 at 25.degree. C., (2) a reinforcing silica filler, (3) a copolymer of R.sub.3 SiO.sub.0.5 units and SiO.sub.2 units in which R represent a monovalent hydrocarbon group having less than 7 carbon atoms, (4) mica and (5) an organic peroxide curing agent.The compositions are useful for providing fire resistant insulation on electrical equipment.

Abstract: A method of protecting carbon/carbon composites against oxidation at high temperatures is disclosed. This comprises coating the composite with a hybrid metal alkoxide/organosilicon polymer. The hybrid polymer is prepared by a method comprising mixing an organosilicon polymer having a plurality of Si-H functional groups with a sufficient quantity to undergo a hydrosilylation reaction of a metal alkenoxide, wherein the metal alkenoxide comprises a metal, metalloid or silicon alkoxide containing at least one alkenoxy group; and initiating the hydrosilylation reaction to form the hybrid polymer.

Abstract: The present invention provides a method for producing silicone rubber moldings composed of a uniform, smooth and hard exterior layer and a relatively soft interior portion. In accordance with this method the surfaces of the mold cavity are coated with an organohydrogenpolysiloxane containing at least two silicon-bonded hydrogen atoms before the curable organosiloxane used to form the interior portion of the molding is injected into the mold cavity and cured.

Abstract: Imidopolysiloxane gums, resins and fluids are made by equilibrating imidocylclopolysiloxanes with organocyclopolysiloxanes, or cohydrolyzing imidosilanes and organosilanes. The resulting imidopolysiloxanes are useful as temperature and solvent resistant resin and fluids and can be converted to temperature and solvent resistant elastomers.

Abstract: The present invention provides novel curable organopolysiloxane composition comprising at least about 50% by weight of a general organopolysiloxane having no more than two vinyl groups and up to about 50% by weight of a crosslink additive which is a polysiloxane having at least three vinyl groups and is copolymerizable with the organopolysiloxane. This curable composition when cured by heat, chemical or, preferably, radiation curing techniques produces crosslinked polysiloxane materials having unique combinations of cone penetration, elongation and tensile strength properties. A preferred use for these materials is as a sealant.

Abstract: A silicone rubber stock, giving an elastomer upon cure by hot air-vulcanization which has a low compression set, is obtained when a silicon composition containing at least two .tbd.SiH groups is added to a silicone rubber base which contains a polydiorganosiloxane gum having at least two alkenyl groups per molecule.

Abstract: Method of spinning fibers and coating from an organopolysilazane composition that can be crosslinked by an energy input. The organopolysilazane composition comprises an organopolysilazane and a free radical generator in an amount effective to crosslink the organopolysilazane. The energy input capable of generated the radical may be provided in the form of heat, ultraviolet radiation, an electron beam, and the like.The crosslinked organopolysilazane compositions exhibit good thermal behavior and, in particular, can be used, after pyrolysis, as precursors of ceramic products.

Abstract: The silicone rubber composition of the invention comprises, as the peroxide curing agent, a neopentane diol derivative represented by the general formulaR.sup.1 --O--O--CO--O--CH.sub.2 --C(CH.sub.3).sub.2 --CH.sub.2 --O--CO--O--O--R.sup.2,in which R.sup.1 and R.sup.2 are each, independently from the other, a monovalent hydrocarbon group having 3 to 10 carbon atoms or a silyl group of the general formula --SiR.sup.3.sub.3, R.sup.3 being a methyl, ethyl or phenyl group, such as trimethyl silyl, in admixture with a diorganopolysiloxane and a reinforcing silica filler. By virtue of this unique formulation, the silicone rubber composition is suitable for hot-air vulcanization without compression as in the vulcanization process by extrusion molding followed by heating in a hot-air oven.

Abstract: Hydroxy functional polysiloxane graft copolymers are provided. The copolymer is crosslinkable by hydroxy-reactive crosslinking agent and, in particular, is suitable for use in thermosetting coating compositions adapted to form a flexible cured coating over a variety of substrates, such as metal and plastic. The copolymer has a number average molecular weight between about 1,300 and about 15,000, has a hydroxyl number between about 30 and about 300, and is the reaction product of carbon-carbon double bond-reactive monoethylenically unsaturated monomer with hydroxy functional carbon-carbon double bond-bearing branched polysiloxane macromonomer. The macromonomer is the reaction product of (i) isocyanato monomer having the formula: ##STR1## with (ii) hydroxy functional polysiloxane reactant containing 0-10 urethane linkages per molecule.

Abstract: The silicone rubber adhesive of the present invention is composed of a particular organopolysiloxane, condensation reaction catalyst and organoperoxide in restricted blending ratios. As a result, a characteristic of the present invention is that various organic materials may be tightly and durably bonded to silicone rubbers by applying the adhesive of the present invention to the surface of a cured silicone rubber and laying on and then curing an organic material such as a synthetic rubber composition, for example, ethylene-propylene terpolymer rubber or chloroprene rubber, or a phenol resin, epoxy resin, etc. In addition, it is also a characteristic of the present invention that silicone rubber may be tightly bonded to various materials by applying the silicone rubber adhesive of the present invention to various organic materials as mentioned above, bringing a silicone rubber composition which contains a curing catalyst into contact and then curing.

Abstract: A process for preparing radiation polymerizable acrylate-functional organopolysiloxane-urethane copolymers by reacting aminofunctional polysiloxanes with acrylated urethane oligomers in the presence of a solvent.

Abstract: Heat-vulcanizable organopolysiloxane compositions well adopted for extrusion and molding, and facilely converted into elastomeric shaped articles having improved physical and electrical properties, e.g., seals and sections, include a diorganopolysiloxane oil containing from 0.05 to 3 mol % of vinylsiloxy recurring units, as well as an amine having a pKa greater than 7.5 in aqueous solution at 25.degree. C. and a boiling point of less than 270.degree. C. at atmospheric pressure.

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: A process of crosslinking a silicone rubber using a combination of an aroyl peroxide and a solid peroxydicarbonate as crosslinking agent. The present process is attended with rapid crosslinking and results in products having favorable end properties, especially with regard to the absence of blooming.

Abstract: A silicone rubber composition suitable for hot-air vulcanization under normal pressure without the disadvantages of surface tackiness and internal voids in the cured rubber products and also free from the problems of corrosiveness to metals and toxicity to workers, which comprises, as the curing agent for the organopolysiloxane, a peroxide derivative of dibenzoyl peroxide which is substituted on each of the benzene nuclei with substituted silyl, e.g. trimethyl silyl, group or a silyl-substituted methyl, e.g. trimethylsilyl methyl, group.