Abstract: This invention relates to a method of preparing a planar optical waveguide assembly comprising the steps of: (i) applying a curable silicone composition to a surface of a substrate to form a film; (ii) exposing the product of step (i) to ultraviolet light to form a lower clad layer; (iii) applying a photo sensitive composition on top of the lower clad layer to form a core layer on top of the lower clad layer, wherein the photo sensitive composition comprises: (A) a siloxane resin composition comprising 0 to 95 mole present of R1SiO3/2 siloxane units, 0 to 95 mole percent of R2SiO3/2 siloxane units, and 1 to 99.

Abstract: The present invention provides a silicone composition that includes an epoxy-functional organopolysiloxane resin and an epoxy-functional organosiloxane oligomer, and a method of preparing optical waveguides using the silicon composition. The present invention also provides a cured silicon composition, and an optical waveguide that includes the cured silicon composition.

Abstract: The present invention provides a silicone composition that includes an epoxy-functional organopolysiloxane resin and an epoxy-functional organosiloxane oligomer, and a method of preparing optical waveguides using the silicon composition. The present invention also provides a cured silicon composition, and an optical waveguide that includes the cured silicon composition.

Abstract: Silicone elastomer base compositions containing a stabilizer are disclosed that provide cured silicone elastomers having improved high temperature performance. The stabilizer comprises carbon black, calcium carbonate, iron oxide, and optionally zinc oxide.

Abstract: Fluorosilicone elastomer base compositions are disclosed containing a stabilizer that provides cured fluorosilicone elastomers having improved high temperature performance. The stabilizer comprises carbon black, calcium carbonate, iron oxide, and optionally zinc oxide. The stabilizer is particularly useful to prepare cured fluorosilicone elastomers for o-rings, connectors, and constructing automotive hosing.

Abstract: Poly(siloxane-acrylate) elastomers with low weep characteristics are formed by the steps of: (A) forming an amine functional alkenyl-containing siloxane by mixing and heating: (a) a polydiorganosiloxane, (b) an amino-functional silane hydrolyzate, (c) an alkenylorganosiloxane, and (d) a base equilibration catalyst, then (B) reacting, at room temperature, the amine functional alkenyl-containing siloxane with an acrylate to form a curable alkenyl-containing poly(siloxane-acrylate) with oxycarbonylethyleneimino-containing organic groups, and (C) curing the alkenyl-containing poly(siloxane-acrylate) to form an poly(siloxane-acrylate) elastomer.

Abstract: A method for densifying particulate silica and a method for compounding a curable silicone composition comprising a reinforcing silica filler. The method is particularly useful for densifying particulate silica to be used as a continuous feed to a compounding apparatus for preparing curable silicone compositions.

Abstract: A method for making hydrophobic non-aggregated colloidal silica comprising reacting an aqueous suspension of a hydrophilic non-aggregated colloidal silica having an average particle diameter greater than about 4 nm with a silicon compound at a pH less than about pH 4 in the presence of a sufficient quantity of a water-miscible organic solvent to facilitate contact of the hydrophilic non-aggregated colloidal silica with the silicon compound. The method is conducted at a temperature within a range of about 20.degree. C. to 250.degree. C. for a period of time sufficient to form a hydrophobic non-aggregated colloidal silica. The hydrophobic non-aggregated colloidal silicas prepared by the present method are particularly useful as fillers in silicone compositions such as adhesives, rubbers, and sealants.

Abstract: A method of controlling silica reinforcement in a curable silicone composition having a desired property related to the silica reinforcement comprising adding to the curable silicone composition a volume fraction of reinforcing silica filler sufficient to provide the desired property, where the volume fraction is determined by use of a regression analysis equation relating the volume fraction, Carman surface area (CSA), and Burnauer-Emmet-Teller surface area (BET) of the reinforcing silica filler to the desired property.

Abstract: A one-component room temperature vulcanizable silicone rubber composition comprising (A) silanol end-terminated polyorganosiloxane base polymer, (B) organotriacyloxysilane cross-linker, (C) polysiloxane-polyether copolymer rheology modifier, and (D) particulate silica. The rheology modifying agent is particularly useful for adjusting the viscosity and plateau stress of the silicone rubber compositions.

Abstract: A curable organosiloxane-polyisobutylene composition comprising 20 to 87 weight percent of a polyisobutylene comprising at least 2 alkenyl groups per molecule, 0.4 to 70 weight percent of a polyorganosiloxane comprising at least 2 silicon-bonded alkenyl groups per molecule, 7 to 50 weight percent of a treated reinforcing silica filler, an amount sufficient to cure the composition of an organohydrogensiloxane crosslinker, and a platinum-group metal hydrosilation catalyst in an amount sufficient to effect curing of the composition. Cured elastomers prepared from the compositions can have improved resistance to gas and vapor permeability.