Abstract: A two part sealant cures rapidly in deep sections when the two parts are mixed together. A first part consists essentially of a hydroxyl endblocked polydiorganosiloxane, non-reinforcing, non-acidic filler, diacetamidosilane chain extender of the general formula ##STR1## and aminoxysilicone compound having from 1 to 100 silicone atoms per molecule and from 3 to 10 aminoxy groups per molecule. A second part consists essentially of a hydroxyl endblocked polydiorganosiloxane, non-reinforcing, non-acidic filler, and water. When mixed together, the two parts cure rapidly in deep sections.

Abstract: A two part sealant cures rapidly in deep sections when the two parts are mixed together. A first part comprises a hydroxyl endblocked polydiorganosiloxane, non-reinforcing, non-acidic filler, diacetamidosilane chain extender of the general formula ##STR1## and aminoxysilicone compound having from 1 to 100 silicone atoms per molecule and from 3 to 10 aminoxy groups per molecule. A second part comprises a hydroxyl endblocked polydiorganosiloxane, non-reinforcing, non-acidic filler, and hydroxyl endblocked polydiorganosiloxane having a degree of substitution of from about 1 to 50. When mixed together, the two parts cure rapidly in deep sections.

Abstract: This invention relates to an organopentasiloxane with the following formula ##STR1## wherein A is the hydrogen atom or an aliphatically unsaturated monovalent hydrocarbon group, R is the same or different monovalent hydrocarbon group, and n is an integer with a value of 2 to 4, which carries silicon-bonded hydrogen or a silicon-bonded, aliphatically unsaturated monovalent hydrocarbon group at one molecular chain terminal and silicon-bonded organoxy group(s) at the other terminal.

Abstract: A hydrophobic silica is prepared by mixing and heating a mixture of (a) 100 weight parts wet-method silica and (b) 1 to 100 weight parts organopolysiloxane represented by the following average unit formula R.sup.1.sub.a R.sup.2.sub.b SiO.sub.(4-a-b)/2, wherein R.sup.1 is a monovalent hydrocarbon group, R.sup.2 is the hydrogen atom, a is from 1 to 3 inclusive, and b is from zero to 1 inclusive, with the provisos that a+b is from 1.90 to 2.10 inclusive and b/(a+b) is from zero to 0.45 inclusive. This hydrophobic silica is used to prepare a high-strength silicone rubber particulate by mixing with a curable dioranopolysiloxane and curing the mixture in the form of particulates. A preferred manner of making the particulates is by emulsifying the mixture of hydrophobic silica and curable diorganopolysiloxane in water, then spraying the emulsion into a hot gas to cure the silicone rubber composition and remove the water, giving microparticles of high-strength silicone rubber.

Abstract: A fluorinated polydiorganosiloxane elastomer having improved physical properties can be obtained through the use of a method which first reacts a hydroxyl endblocked trifluoropropylmethylsiloxane having a Williams Plasticity Number of greater than 225 with a methylvinyldi(N-alkylacetamido)silane to give a chain extended polymer having pendant vinyl groups only at the location of the chain extension. The polymer is then reinforced with fume silica and compounded into a stock. The cured stock has improved tensile strength and tear strength when compared to similar compositions which do not contain the same type of polymer. The polymer has pendant vinyl groups located along the polymer chain, with the distance between them being relatively large. When too many vinyl pendent groups are present along the chain, the improved results are not obtained.

Abstract: An improved aqueous silicone emulsion which cures to a reinforced elastomer upon removal of water is obtained through the use of an anionic, stable dispersion of fumed silica in water as the source of reinforcing silica. The fumed silica dispersion is combined with an aqueous, anionic emulsion of crosslinkable polydiorganosiloxane and a crosslinking system.

Abstract: A method for the manufacture of silicone rubber moldings comprises the preparation of a silicone rubber composition by blending an organoperoxide having an activation energy of 25 to 41 kcal/mol into a semicurable organopolysiloxane composition whose main component is organopolysiloxane having organoperoxide-crosslinkable functional groups. The silicone rubber composition is made into a particulate form and heated at a temperature below 100 degrees Centigrade to produce a semicured, particulate molding material which retains the activity of the organoperoxide and which contains residual crosslinkable functional group on the organopolysiloxane. Subsequently a mold is filled with the molding material and the mold material is completely cured at a temperature of at least 100 degrees Centigrade under the application of pressure. The method is particularly useful for automatic molding methods.

Abstract: A method is disclosed for preparing a heterogeneous silicone rubber molding wherein a portion of the molding is formed from a semicured silicone rubber particulate and a portion from a thermosetting silicone rubber composition. The mold is filled with the particulate and the thermosetting silicone rubber composition, then closed and pressurized and heated, forming the portions into a single body or element by curing the thermosetting silicone rubber composition at the same time that curing of the semicured silicone rubber particulate is brought to completion.

Abstract: A shelf stable aqueous silicone emulsion which yields an elastomer upon removal of the water is produced by combining a reactive polydiorganosiloxane present as a cationic or nonionic emulsion of dispersed particles in water, a crosslinker, and a tin catalyst, the tin catalyst being in the form of a divalent tin atom combined with organic radicals. The emulsion can be reinforced with colloidal silica without effecting the shelf life of the reinforced emulsion.

Abstract: A composition useful for adhering polysulfide sealant to silicone sealant or to silicone sealant contaminated surfaces is obtained by mixing 1 part by weight of alkoxy functional, titanate catalyzed silicone sealant with from 0.1 to 40 parts by eight of polysulfide sealant.

Abstract: An optical laminate having improved resistance to delamination upon exposure to moisture consists essentially of a layer of organosiloxane composition, a primer layer, and a layer of organic elastomer. The organosiloxane composition comprises a polydiorganosiloxane gum containing at least two ethylenically unsaturated hydrocarbon radicals per molecule, an organohydrogensiloxane containing at least two silicon-bonded hydrogen atoms per molecule, and a platinum containing hydrosilation catalyst. The primer comprises a specific mixture of organosilicone compound, silane copolymer, organohydrogensiloxane, and solvent being as least 50 percent of an ethylenically unsaturated alcohol. The organic elastomer is selected from a polyvinylbutyral or polyurethane of the types used for optical laminates.

Abstract: A curable polydiorganosiloxane is reinforced by mixing with a modified polyvinylalcohol (PVA). Fully hydrolyzed PVA is modified by dissolving or swelling in solvent, then adding a silylating agent of the formula R".sub.b (R'.sub.2 SiO).sub.n SiR.sub.a X.sub.4-a where R is a group capable of undergoing hydrolysis to form a siloxane bond with the curable polydiorganosiloxane, R' is a monovalent alkyl or aryl radical having from 1 to 6 carbon atoms, optionally halogen substituted, and compatible with the curable polydiorganosiloxane, R" is either R or R', X is a radical reactive with the hydroxyl on the PVA, a and b are integers of 0 to 3 inclusive, the sum of a plus b is from 1 to 3 inclusive, and n is from 0 to 35. This modified PVA is then mixed with the curable polydiorganosiloxane. The polydiorganosiloxane is then cured and the solvent is extracted to yield a cured polydiorganosiloxane reinforced with polyvinylalcohol.

Abstract: A curable polydiorganosiloxane is reinforced by mixing with a solution of polyvinylalcohol (PVA) or a modified PVA. The polydiorganosiloxane is then cured and the solvent is extracted to yield a cured polydiorganosiloxane reinforced with PVA.

Abstract: A fine powder is obtained by first dissolving polyvinylalcohol and tetraalkoxysilicate in a common solvent to obtain a reaction product, then spraying a fine mist of a solution of the reaction product into a coagulating bath of a solvent which is miscible with the common solvent, but a poor solvent for the reaction product. After drying, the fine particles obtained are useful as filler in polydiorganosiloxane compositions.

Abstract: The specification describes and claims filled compositions, e.g. moisture curable sealant compositions which comprise 100 parts by weight of polymeric material comprising a mixture and/or a reaction product of a polydiorganosiloxane having silicon-bonded hydroxyl groups with a compound containing silicon-bonded alkoxy or alkoxyalkoxy groups, 50 to 200 parts by weight of finely divided filler and an additive which is a reaction product of an organic amine, an oxide, hydroxide, carbonate, bicarbonate or a mixture thereof with a sulphonic acid of the formula RSO.sub.3 H in which R represents a hydrocarbon group which may be halogenated. The additive is preferably a reaction product of the sulphonic acid and an oxide, hydroxide, carbonate or bicarbonate of magnesium, or calcium and the acid is preferably one in which R represents a group R'C.sub.6 H.sub.4 wherein R' represents an alkyl group having 6 to 18 carbon atoms, for example dodecylbenzenesulphonic acid.

Abstract: An ionically conductive material comprises crosslinked copolymer prepared by the reaction of (A) organopolysiloxane and polyoxyalkylene copolymer, which has at least 2 silicon-bonded hydrogen atoms in each molecule, with (B) polyoxyalkylene having at least 2 aliphatically unsaturated hydrocarbon groups in each molecule, and (C) metal ion from Group I or Group II of the Periodic Table, wherein said metal ion is dispersed in said crosslinked copolymer. Component (B) is a polyoxyalkylene having an aliphatically unsaturated hydrocarbon group at both chain terminals or a mixture of molecules in which some have an aliphatically unsaturated hydrocarbon group at both ends and some having the group at only one end. This mixture gives the highest conductivity.

Abstract: A silicone emulsion is prepared by emulsion polymerizing a hydroxyl endblocked polydiorganosiloxane oligomer with a combination of a siloxane or siloxane precursor containing unsaturated hydrocarbon groups and a functional silicone selected from the group consisting of organosilicon hydrides and mercaptoalkylsilanes or siloxanes, or with an acryl or methacryl functional siloxane. When the emulsion of the copolymer produced is combined with a photoinitiator, the copolymer can be crosslinked by exposure to ultraviolet radiation. When the water is removed, an elastomer results. The emulsion can be used to produce coatings and sealants.

Abstract: A method of bonding a silicone elastomer to a substrate which comprises treating the surface of the substrate with a cleaning agent which is a polydiorganosiloxane, for example a polydimethylsiloxane, and thereafter applying to the treated surface a room temperture curing silicone elastomer-forming composition.The method finds particular application in the construction industry for the bonding of sealants to non-porous substrates such as aluminum.

Abstract: A method of producing a conductive silicone rubber particulate is disclosed in which the particulate is from 0.1 to 100 micrometers average diameter and is coated on the surface with carbon black. The method prepares an aqueous dispersion of silicone rubber composition particulate, carbon black, surfactant, and water, then removes the water.

Abstract: A silicone emulsion is prepared by emulsion polymerizing a hydroxyl endblocked polydiorganosiloxane oligomer with a combination of a siloxane or siloxane precursor containing unsaturated hydrocarbon groups and a functional silicone selected from the group consisting of organosilicon hydrides and mercaptoalkylsilanes or siloxanes, or with an acryl or methacryl functional siloxane. When the emulsion of the copolymer produced is combined with a photoinitiator, the copolymer can be crosslinked by exposure to ultraviolet radiation. When the water is removed, an elastomer results. The emulsion can be used to produce coatings and sealants.