Abstract: A method of improving the heat stability of silicone elastomers is disclosed. An improved pigmentable silicone elastomeric composition is produced by mixing a silicone elastomer composition having a vinyl radical content of from 0.01 to 0.1 percent by weight with a pretreated, white clay having a surface area of less than 50 m.sup.2 /g, said surface containing olefinic unsaturated siloxy groups, and an organic peroxide vulcanizing agent. The improved silicone elastomeric composition is formed, then heated to vulcanize, to yield a silicone elastomer having improved resistance to the effects of elevated temperatures. The improved silicone elastomeric composition is also claimed. The improved silicone elastomeric composition can be pigmented.

Abstract: According to the present invention, an aqueous silicone emulsion composition is produced as follows. A base emulsion is prepared from prescribed quantities of an essentially straight-chain organopolysiloxane with at least 2 silicon-bonded hydroxyl groups in each molecule, colloidal silica or alkali metal silicate, a curing catalyst, an emulsifier and water. After the pH is adjusted to 9 to 12 and ripened until an elastomer material is formed by the removal of water at room temperature, prescribed quantities of an epoxy-functional silane coupling agent or its partial hydrolysis product or its partial hydrolysis condensation product, a filler and a dispersant are added. The produced aqueous silicone emulsion composition bonds tightly to porous substrates in contact with it during curing and is therefore extremely useful as a coating or sealing material for various porous substrates.

Abstract: A method of constructing a weatherproof coating over a roof comprises laying a piece or pieces of cloth over a roof, bonding the pieces of cloth together at any seams, adhering the cloth to the roof surface at least at the edges and projections, then coating the cloth with a liquid elastomeric silicone composition. The composition cures under ambient conditions to yield a water impermeable membrane that has been manufactured in place. A preferred embodiment uses unimpregnated, non-woven thermoplastic cloth having an upper surface thermally treated to remove projecting fibers, the thermally treated surface being subsequently wash coated with a layer of liquid elastomeric silicone emulsion except for any surface of the cloth edges which will be subsequently bonded at any seams, the wash coating being cured before application of the coated cloth to the roof.

Abstract: This invention is a method of producing a colloidal silica reinforced polydiorganosiloxane fluid in aqueous emulsion. The method combines an acidic aqueous colloidal silica sol and low molecular weight hydroxyl endblocked polydiorganosiloxane with anionic emulsifying agent, then homogenizes the mixture to form an emulsion. Because the water in the colloidal silica sol is used to supply water for the emulsion, it is possible to produce emulsions with solid content as high as 80 percent by weight. The emulsion is then mixed with surface active anionic catalyst and aged at room temperature to allow the polydiorganosiloxane to polymerize. Polymerization is halted by adding base to bring the pH to greater than 7. The reinforced polydiorganosiloxane emulsion can be further mixed with diorganotindicarboxylate and aged to give a curable emulsion which yields an elastomer upon removal of the water.

Abstract: This invention is a method of improving the shelf life and oil resistance of silicone elastomeric sealants which are based upon hydroxyl endblocked polydiorganosiloxanes, alkyltrialkoxysilane, and titanate catalyst. The improvement is accomplished by the addition of from 10 to 100 parts by weight of silethylene ended polymer of the formula ##STR1## where each R is an organic radical selected from methyl, ethyl, propyl, phenyl, and trifluoropropyl, each R" is methyl or ethyl, Z is an ethylene radical or combination of ethylene radicals and siloxane radicals, a is 0 or 1, and x is of a value such that the polymer has a viscosity of from 0.05 to 10 Pa.s at 25.degree. C.

Abstract: This invention describes a method of producing a silicone elastomer from an emulsion. When the ingredients are mixed together, the resulting latex can be used immediately. Removing the water from the latex results in a silicone elastomer. The method combines (A) an anionically stabilized, hydroxyl endblocked polydiorganosiloxane, present as an emulsion of dispersed particles in water, the emulsion having a pH of greater than 9, (B) dialkyltindicarboxylate, (C) alkylorthosilicate, (D) colloidal silica, and optionally (E) water, admixing (A) and (B) only in the presence of (C) to produce a dispersion of the ingredients in water. The ingredients can be distributed into a two-part system for storage. One embodiment includes fibers, lauryl alcohol, or a mixture of both in the emulsion; then forms an open-cell, elastomeric foam by forming a froth from the emulsion and removing the water from the froth.

Abstract: The method of this invention admixes in a high shear mixer 100 parts by weight of polydiorganosiloxane gum plasticizer chopped organic or inorganic fibers, and then when the fibers are uniformly mixed from 1 to 60 parts of reinforcing silica filler. The uniform mixture is then heated with mixing, under vacuum, optionally with nitrogen containing catalyst, to treat the filler and remove any volatiles, then cooled to give a uniform mixture with the fibers well dispersed throughout the mixture.

Abstract: This invention describes a method of producing a silicone elastomer from an emulsion. When the ingredients are mixed together, the resulting latex can be used immediately. Removing the water from the latex results in a silicone elastomer. The method combines (A) an anionically stabilized, hydroxyl endblocked polydiorganosiloxane, present as an emulsion of dispersed particles in water, the emulsion having a pH of greater than 9, (B) dialkyltindicarboxylate, (C) alkylorthosilicate, (D) colloidal silica, and optionally (E) water, admixing (A) and (B) only in the presence of (C) to produce a dispersion of the ingredients in water. The ingredients can be distributed into a two-part system for storage. One embodiment includes fibers, lauryl alcohol, or a mixture of both in the emulsion; then forms an open-cell, elastomeric foam by forming a froth from the emulsion and removing the water from the froth.

Abstract: This invention describes a method of producing a silicone elastomer from an emulsion. When the ingredients are mixed together, the resulting latex can be used immediately. Removing the water from the latex results in a silicone elastomer. The method combines (A) an anionically stabilized, hydroxyl endblocked polydiorganosiloxane, present as an emulsion of dispersed particles in water, the emulsion having a pH of greater than 9, (B) dialkyltindicarboxylate, (C) alkylorthosilicate, (D) colloidal silica, and optionally (E) water, admixing (A) and (B) only in the presence of (C) to produce a dispersion of the ingredients in water. The ingredients can be distributed into a two-part system for storage. One embodiment includes fibers, lauryl alcohol, or a mixture of both in the emulsion; then forms an open-cell, elastomeric foam by forming a froth from the emulsion and removing the water from the froth.

Abstract: An aqueous silicone elastomeric emulsion is a storage stable, paste-type material useful as a caulking material. The caulking material is obtained by mixing an anionic emulsion containing dispersed particles of hydroxyl endblocked polydiorganosiloxane, dialkyltindicarboxylate, silane of the formula RSi(OR').sub.3 where R is a monovalent hydrocarbon radical of from 1 to 4 carbon atoms inclusive and R' is a lower alkyl radical of from 1 to 4 carbon atoms inclusive or a radical of the formula --N.dbd.CR.sub.2, and inert, non-siliceous filler.

Abstract: A method of producing an emulsion of crosslinked polydiorganosiloxane admixes hydroxyl endblocked polydiorganosiloxane, alkoxy silicone compound, anionic emulsifying agent, and water. The mixture is homogenized, then the emulsion is admixed with surface active anionic catalyst. Maintaining the catalyzed emulsion, having a pH of less than 5, at room temperature allows the ingredients to react to raise the molecular weight of the polydiorganosiloxane and to crosslink the polymer. The reaction is halted by adding sufficient base to raise the pH to greater than 7. The resultant latex yields an elastomer upon removal of the water. When colloidal silica is also added to the mixture before homogenization, the final latex yields a reinforced elastomer upon removal of the water.

Abstract: A method of preparing a copolymer of methyl(2-phenylpropyl)siloxy units and dialkylsiloxy units is disclosed. The method hydrolyzes methyl(2-phenylpropyl)dichlorosilane to yield a reaction product of primarily methyl(2-phenylpropyl)disiloxanediol, then copolymerizes the reaction product with dialkylcyclosiloxane to give the copolymer. The copolymer has a crystallinity point of less than -50.degree. C. It is useful in producing silicone elastomers and sealants having a comparably low crystallinity point.

Abstract: A one-part silicone elastomeric composition that is flowable or easily extruded is prepared by mixing a hydroxyl endblocked polydiorganosiloxane, a difunctional silane having two amido radicals, and an organic peroxide suitable for vulcanizing silicone rubber. A nonacidic filler is optional. After being put in place, the composition is exposed to moisture to activate a chain extension reaction that increases the molecular weight of the polydiorganosiloxane, to improve the physical properties of the cured silicone elastomer. After chain extension has taken place, the composition is heated to activate the organic peroxide, thereby crosslinking the composition into a silicone elastomer. The composition is useful as a potting and encapsulating material.

Abstract: This invention relates to a method of producing silicone elastomeric foam of low density. The method mixes polydiorganosiloxanes having hydroxyl endblocking or vinyl endblocking or mixtures of both along with water to react with silicon hydride in the presence of platinum catalyst to release hydrogen gas to create a froth which cures to a foam. The combination of ingredients allows the manufacture of silicone foam having different combinations of properties than those obtained from previous methods. Embodiments of the invention also make use of specific profoamers and specific alcohols to further modify the properties of the foams produced. The method of this invention yields a low cost, low density, silicone elastomeric foam having physical properties which enable it to be used in cushioning and sealing applications.

Abstract: This invention relates to a method of permanently bonding surfaces coated with elastoplastic organopolysiloxane resin or polytetrafluoroethylene resin. The method of bonding these difficult to adhere surfaces consists essentially of applying to the surface sufficient adhesive to yield at least a 0.1 mm coating of an adhesive comprising the product obtained by mixing (i) 9 to 70 percent by weight of a solid benzene soluble silicone resin copolymer, (ii) 30 to 91 percent by weight of a hydroxyl endlblocked polydiorganosiloxane gum having a viscosity of greater than 10,000 Pa.sup.. s, (iii) an organohydrogenpolysiloxane compatible with (i) and (ii), (iv) a soluble tin catalyst, and (v) a non-reactive solvent. The applied adhesive is allowed to become tacky, then the tacky surfaces are placed firmly together and allowed to cure.

Abstract: The shelf life of an aqueous, anionic silicone emulsion, which contains an organic tin compound and which forms an elastomer upon removal of the water, is improved by the addition of an additive. The additive is selected from the group consisting of alkyl mercaptan, 8-quinolinol, thioglycolic acid, and salts of thioglycolic acid. Elastomers produced by removing the water from these emulsions, once shelf aged, have more consistent physical properties than do elastomers produced from similar emulsions not containing the additives.

Abstract: A silicone caulking material obtained by mixing an anionically stabilized, hydroxyl endblocked polydiorganosiloxane in an aqueous emulsion, dialkyltindicarboxylate, alkylorthosilicate, and inert, non-siliceous filler is capable of yielding an elastomer upon removal of the water immediately upon mixing of the ingredients. When the caulking material also contains 2-amino-2-methyl-1-propanol, the emulsion also has a useful shelf life in that the emulsion shows no gelation upon aging. The physical properties of the elastomer produced by removing the water from the emulsion do not change appreciably during the useful life of the caulking material.

Abstract: A method of producing elastomeric silicone foams from a two-part system is disclosed. The method mixes the ingredients then allows a froth to form and cure at ambient temperature to an elastomeric silicone foam. The method mixes a vinyl-containing polydiorganosiloxane (1), a hydroxylated polydiorganosiloxane (2), a platinum catalyst (3), an organohydrogensiloxane (4) and a profoamer (5). The profoamer is a resinous, benzene-soluble organosiloxane copolymer consisting essentially of SiO.sub.4/2 units, silicone bonded hydroxyl groups, (CH.sub.3).sub.3 SiO.sub.1/2 units, and fluorine-containing units. An embodiment of the method includes a liquified blowing agent and stores the mixture under superatmospheric pressure, forming a foam by releasing the mixture to atmospheric pressure. Another embodiment includes an alcohol in the mixture to provide a foam of lower density.

Abstract: Composition comprising the product obtained by mixing (A) a silanol-terminated polydiorganosiloxane; (B) a silicon compound having at least 3 silicon-bonded alkoxy or alkoxyalkoxy groups in the molecule; (C) a metal or organometal salt of a carboxylic acid; (D) a silane having silicon-bonded alkoxy or alkoxyalkoxy groups and a silicon-bonded group, --R'NHR, in which R' is alkylene and R represents H, alkyl or an aliphatic hydrocarbon group containing at least one amino group, and (E) a silane having silicon-bonded alkoxy or alkoxyalkoxy groups and a silicon-bonded group containing an epoxy group.The compositions cure to elastomers having improved adhesion to glass, aluminium and concrete and are suitable for use as sealants for buildings.

Abstract: This invention relates to a method of producing silicone elastomeric foam of low density. The method mixes polydiorganosiloxanes having hydroxyl endblocking or vinyl endblocking or mixtures of both along with water to react with silicon hydride in the presence of platinum catalyst to release hydrogen gas to create a froth which cures to a foam. The combination of ingredients allows the manufacture of silicone foam having different combinations of properties than those obtained from previous methods. Embodiments of the invention also make use of specific profoamers and specific alcohols to further modify the properties of the foams produced. The method of this invention yields a low cost, low density, silicone elastomeric foam having physical properties which enable it to be used in cushioning and sealing applications.