Abstract: The present invention is a curable fluorosilicone composition having improved lubricity, low compression set, and good resistance to fluids such as automotive fuel without post-curing. The composition comprises(A) poly(trifluoropropyl)methylsiloxane, (B) vinylmethyldi(N-alkylacetamido)silane, (C) reinforcing treated silica, (D) chlorotrifluoroethylene polymer, and (E) vinyl specific organic peroxide catalyst.

Abstract: A room temperature curable organosiloxane composition, containing an alkenyl-containing polyorganosiloxane, an organohydrogensiloxane, a platinum catalyst, a methylvinylcyclosiloxane and an acetylenic alcohol, which exhibits a long working time and a fast cure time.

Abstract: A method for making a fluorinated polydiorganosiloxane base composition and the composition prepared thereby. The base composition can be addition cured using a platinum-metal group catalyst and an organohydrogensiloxane crosslinker to form a fluorosilicone elastomer having improved resiliency and compression set properties.

Abstract: The compatibility between high consistency fluorinated and non-fluorinated polydiorganosiloxanes is increased, with a resultant increase in the physical-properties of elastomers prepared from mixtures of these polymers, by blending the polymers together with a reinforcing silica filler that is reacted with both fluorinated and non-fluorinated liquid polydiorganosiloxanes as filler treating agents. The high consistency polydiorganosiloxanes contain at least two alkenyl radicals per molecule and are cured by a hydrosilation reaction.

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: A method of reducing the compression set of a silicone elastomer is accomplished by mixing an alkenyl silazane with a previously prepared, based heated, silanol-containing silicone elastomer base. Fluorosilicone elastomers prepared by these methods find use in gasketing and sealing application which are exposed to fuels and solvents.

Abstract: N,N,N',N'-tetraalkylalkylenediamines are unique with respect to their ability to impart long term storage stability to curable fluorosilicone gel compositions. While the present compositions cure realtively rapidly at temperature of 150.degree. C. and above in bulk, small amounts of the compositions in the form of coatings and encapsulants cure in as little as 15 minutes at these temperatures.

Abstract: Certain liquid polydiorganosiloxanes wherein each molecule contains at least one sequence of 2 or more vinyl radicals bonded to non-terminal silicon atoms extend the working time at 25.degree. C. of organosiloxane compositions that cure by a platinum catalyzed hydrosilation reaction without adversely affecting the cure rate of the composition at temperatures of about 100.degree. C. and above. These polydiorganosiloxanes can constitute up to 100 percent of the vinyl-containing polydiorganosiloxanes present in said organosiloxane compositions and are prepared by polymerizing the corresponding cyclosiloxanes in the presence of an acid catalyst.

Abstract: A fluorosilicone rubber with low compression set and other physical properties which are either are not significantly effected or are improved are made by curing a composition of a polydiorganosiloxane having 3,3,3-trifluoropropylsiloxane units and endblocked with vinyl or silacyclopentenyl groups, a reinforcing silica having dimethyl(3,3,3-trifluoropropyl)siloxy units as the surface treatment, and a vinyl specific organic peroxide. The polydiorganosiloxane endblocking is done by reacting a silanol endblocked polymer with a silazane.

Abstract: The method of this invention produces a high strength, one-part fluorosilicone sealant which is stable in the absence of moisture and contains an in situ treated reinforcing silica filler. The fluorosilicone sealant is produced by a process which in situ treats the reinforcing filler with a di(trifluoropropyl)tetramethyldisilazane in the presence of a portion of the fluorosilicone polymer. The remainder of the polymer is then added and the reinforced polymer is admixed with a moisture activated curing system to give a sealant which cures upon exposure to moisture to give an elastomer. The sealant is easily extrudable from a storage container. The cured elastomer has improved tensile strength, tear strength, and elongation values. The cured elastomer, being a fluorosilicone, is resistant to non-polar organic hydrocarbon fluids such as aircraft jet engine fuels and gasoline.

Abstract: The presence of an incompatible liquid, polydiorganosiloxane wherein from 1 to 30 percent of the siloxane units contain an ethylenically unsaturated hydrocarbon radical in high-consistency organosiloxane compositions that cure by a platinum-catalyzed hydrosilation reaction substantially improves the tear strength and elongation of cured elastomers prepared from these compositions.

Abstract: Certain liquid polydiorganosiloxanes wherein each molecule contains at least one sequence of 2 or more vinyl radicals bonded to non-terminal silicon atoms extend the working time at 25.degree. C. of organosiloxane compositions that cure by a platinum catalyzed hydrosilation reaction without adversely affecting the cure rate of the composition at temperatures of about 100.degree. C. and above. The polydiorganosiloxane is prepared by the acid-catalyzed polymerization of the corresponding cyclic polydiorganosiloxanes in the presence of a chain-terminating organosilicon reactant.

Abstract: The curable compositions of this invention comprise a solubilized vinyl-containing fluorosilicone gum, a curing agent for the gum, a platinum-containing hydrosilation catalyst, a treated reinforcing silica filler, and a volatile solvent for the gum and curing agent. The organosilicon compound used to treat the silica filler is critical to obtaining a homogeneous curable composition free of agglomerated particles, and is a hydroxyl terminated polydiorganosiloxane containing silicon-bonded fluorocarbon radicals.

Abstract: Polyorganosiloxane gels exhibiting a resistance to discoloration and hardening at temperatures of 100.degree. C. and above can be prepared by the reaction of a polydiorganosiloxane containing silicon-bonded fluorinated hydrocarbon radicals with an organohydrogensiloxane containing at least three silicon-bonded hydrogen atoms per molecule in the presence of a platinium containing catalyst. The resistance to heat induced hardening and discoloration is achieved by preparing the polydiorganosiloxane by the ammonia catalyzed polymerization of at least one cyclic fluorine-containing diorganosiloxane followed by reaction of the resultant silanol terminated polymer with a hexaorganodisilazane containing a vinyl radical bonded to each of the two silicon atoms.The reactants preferably contain 3,3,3-trifluoropropyl radicals to achieve a resistance to softening and/or solubilization of the cured gel in the presence of hydrocarbon fuels.

Abstract: A method of producing a one-part silicone elastomeric sealant which has improved shelf life and an economical process of manufacture is disclosed. The method mixes a diorganovinylsiloxy endblocked polydiorganosiloxane, reinforcing filler, and a silazane. This reinforced base is then converted by reacting with a silane of the formulaH[SiR.sub.2 OSiR.sub.2 CH.sub.2 CH.sub.2 ].sub.b SiR.sub.a (OR").sub.3-awhere R is methyl, ethyl, propyl, phenyl or trifluoropropyl, R" is methyl or ethyl, a is 0 or 1, and b is 0 or 1 using a platinum catalyst. The result is a base containing an alkoxy functional polymer. This base is then mixed with alkoxy functional silane crosslinker and titanium catalyst to yield a composition which is stable in the absence of moisture for long periods of time in storage, but cures to an elastomer upon exposure to moisture. The improved shelf life is due to the presence of alkylene radicals between the penultimate silicon atom and the last silicon atom of the polymer.

Abstract: Siloxane gels which exhibit low temperature properties are obtained without the preparation of special polymers. The compositions form the low temperature branching in situ by mixing polydiorganosiloxane having dimethylsiloxane units and methylvinylsiloxane units with a methylhydrogensiloxane crosslinking mixture of monofunctional methylhydrogensiloxane and difunctional methylhydrogensiloxane in the presence of an addition reaction catalyst. The viscosity and the low temperature properties can be controlled.

Abstract: Liquid diorganovinylsiloxy terminated polydiorganosiloxanes wherein at least 50 percent of the hydrocarbon radicals bonded to silicon contain at least one perfluorinated carbon atom are prepared by polymerizing the corresponding diorganocyclosiloxane(s) at a temperature of from 25.degree. to 150.degree. C. under superatmospheric pressure and in the presence of a controlled amount of water and a catalytically effective amount of ammonia. The resultant silanol terminated polydiorganosiloxane is reacted with a hexaorganodisilazane containing a vinyl radical bonded to each of the two silicon atoms.

Abstract: A process for the neutralization of the alkali metal catalyst in a polymerized organopolysiloxane where the alkali metal content of the resulting organopolysiloxane is significantly reduced, is described. The process consists of neutralizing the alkali metal salt with a straight-chain carboxylic acid of general formula ZCOOH, where Z is a hydrocarbon group containing at least two carbon atoms, and thereafter filtering the organopolysiloxane. The same ZCOOH carboxylic acids may be added to organopolysiloxanes which have previously been neutralized with either carbon dioxide or acetic acid in order to significantly reduce the alkali metal content of the organopolysiloxane after filtration. Organopolysiloxanes containing less than 0.5 ppm K.sup.+ can be easily obtained.

Abstract: Polymethylsiloxanes containing silicon-bonded hydrogen exhibit low temperature properties and can be made into gels with which also exhibit low temperature properties or into elastomeric materials. The polymethylsiloxanes have 84 to 96 mole percent dimethylsiloxane units, 0.5 to 6 mole percent trimethylsiloxy units, 2 to 10 mole percent methylsilsesquioxane units, and 0.25 to 3 mole percent monohydrogendimethylsiloxy units and the total mole percent of the trimethylsiloxy units and the monohydrogendimethylsiloxy units is at least 1.5.

Abstract: A silicone composition useful as a caulking material consists essentially of an aqueous emulsion of a hydroxyl endblocked polydiorganosiloxane, dialkyltindicarboxylate, phenyltrimethoxysilane, and inert non-siliceous filler. The composition is of a paste-type viscosity while an emulsion, then becomes a soft, putty-type material having a plasticity number of from 125 to 300 when the water is removed from the emulsion. The dried composition remains a soft, putty-like material upon aging.