Abstract: A hydrosilylation curable polysiloxane comprising at least one of units of formula (I) and units of formula (II), wherein Ar is C6-C20 aryl, R1 is C2-C20 alkenyl, and R2, R3, R4 and R5 independently are C1-C20 hydrocarbyl.

Abstract: A hydrosilylation curable polysiloxane comprising at least one of units of formula (I) and units of formula (II), wherein Ar is C6-C20 aryl, R1 is C2-C20 alkenyl, and R2, R3, R4 and R5 independently are C1-C20 hydrocarbyl.

Abstract: Provided is a resin-linear organopolysiloxane block copolymer which has a high degree of freedom in formulation due to excellent compatibility with other materials, in addition to exhibiting excellent film forming properties and followability of a film, while the stickiness of a film is suppressed. The resin-linear organopolysiloxane block copolymer has: a resin structure (A1) block that has siloxane units represented by R1SiO3/2 (wherein R1 represents a monovalent organic group, a hydroxyl group, or an alkoxy group having 1 to 6 carbon atoms) and SiO4/2; and a linear structure (A2) block represented by (R2SiO2/2)n (wherein n represents a number of 5 or more while R represents an alkyl group, a fluoroalkyl group, or an aryl group) in each molecule. The resin structure (A1) and the linear structure (A2) are linked to each other by an Si—O—Si bond, and an Si atom bonded to the resin structure (A1) constitutes an RSiO3/2 unit.

Abstract: A method for producing a sealed optical semiconductor device includes: placing inner and outermost layer sealing films on a substrate on which an optical semiconductor element is mounted within a pressure reduction chamber, and reducing the pressure; a step in which the outermost film is heated, and at least the periphery of the outermost film is thermally fused to the surface of the substrate; and a step in which the reduction of pressure is released, and the substrate is sealed by the outermost film and the inner film. The temperature T2 of the substrate when the reduction of pressure is released is a temperature at which the outermost film exhibits a tensile strength of 0.02-0.15 MPa and an elongation at break of 200-450%. The inner film exhibits a loss tangent (tan ?) of 1.6 or more at the temperature T2.

Abstract: A method for preparing a graft copolymer having a polyolefin backbone and polyorganosiloxane pendant groups can be catalyzed by a Lewis Acid catalyst, Piers-Rubenstzjan catalyst, or hydrosilylation reaction catalyst. The graft copolymer prepared by the method is useful as a thermoplastic elastomer or as a compatibilizer in compositions containing both a polyolefin and a polyorganosiloxane.

Abstract: A composition comprising: (a) a component comprising units of Ar1SiO3/2, wherein Ar1 is C6-C20 aryl and units of PhCH3SiO2/2, and having Mw from 20,000 to 90,000; and (b) an elastomeric component comprising: (i) a straight-chain organopolysiloxane having at least two silicon-bonded alkenyl groups and at least one silicon-bonded aryl group; (ii) a branched-chain organopolysiloxane having formula: (RSiO3/2)a(R2SiO2/2)b(R3SiO1/2)c(SiO4/2)d(XO1/2)e where each R is the same or different C1-C20 hydrocarbyl group, 0.1 to 40 mole % of all R's are alkenyl, more than 10 mole % of all R's are C6-C20 aryl, X is a hydrogen atom or alkyl, a is 0.45 to 0.95, b is 0 to 0.25, c is 0.05 to 0.5, d is 0 to 0.1, e is 0 to 0.1, c/a is 0.1 to 0.5; (iii) an organopolysiloxane having at least two silicon-bonded hydrogen atoms; and (iv) a hydrosilylation catalyst.

Abstract: A polysiloxane comprising: (a) from 40 to 90 mole % units of formula R1R2SiO2/2, (b) from 10 to 60 mole % units of formula R3SiO3/2, and (c) from 0 to 5 mole % units of formula R1R4SiO2/2; wherein R1 and R2 independently are phenyl or C1-C6 alkyl; R3 represents at least one C1-C30 hydrocarbyl group; R4 is —Ar1-X—Ar2, where Ar1 and Ar2 independently are C6-C12 aryl and X is O CH2; provided that the polysiloxane comprises at least one —Ar1-X—Ar2 group.

Abstract: A silicone resin-linear co-polymer is disclosed. The silicone resin-linear copolymer includes a resinous structure having the general formula (1): (R1R2R3SiO1/2)x(R4SiO3/2)y ??(1) wherein each R1, R2, R3 and R4 is an independently selected substituted or unsubstituted hydrocarbyl group, with the proviso that in one molecular at least two of R1, R2, and R3 are aryl groups; and x and y are each from >0 to <1 such that x+y=1; and a linear structure having the general formula (2): (R5R6SiO2/2) ??(2) wherein R5 and R6 are each independently selected substituted or unsubstituted hydrocarbyl groups. End use applications and related methods of the silicone resin-linear copolymer are also disclosed.

Abstract: A cosmetic composition and a topical composition containing a resin-linear organopolysiloxane block copolymer are provided, which are excellent in compatibility with other cosmetic raw materials, so as to have a high degree of freedom in formulation design, excellent film forming properties and film following properties, and suppressed tackiness of the film. The resin-linear organopolysiloxane block copolymer contains a resin-linear organopolysiloxane block copolymer (A) having a structure in which a resin structure (A1) block having a siloxane unit represented by R1SiO3/2 (where R1 is a monovalent organic group, a hydroxyl group, or an alkoxy group having 1 to 6 carbon atoms) or by SiO4/2 and a linear structure (A2) block represented by (R2SiO2/2)n (where n is a number of 5 or more, R is an alkyl group, a fluoroalkyl group, or an aryl group) are connected by a Si—O—Si bond and has an R1SiO3/2 unit.

Abstract: Provided is a resin-linear organopolysiloxane block copolymer which has a high degree of freedom in formulation due to excellent compatibility with other materials, in addition to exhibiting excellent film forming properties and followability of a film, while the stickiness of a film is suppressed. The resin-linear organopolysiloxane block copolymer has: a resin structure (A1) block that has siloxane units represented by R1SiO3/2 (wherein R1 represents a monovalent organic group, a hydroxyl group, or an alkoxy group having 1 to 6 carbon atoms) and SiO4/2; and a linear structure (A2) block represented by (R2SiO2/2)n (wherein n represents a number of 5 or more while R represents an alkyl group, a fluoroalkyl group, or an aryl group) in each molecule. The resin structure (A1) and the linear structure (A2) are linked to each other by an Si—O—Si bond, and an Si atom bonded to the resin structure (A1) constitutes an RSiO3/2 unit.

Abstract: A silicone resin-linear copolymer is disclosed which has a resinous structure (A1) including R1SiO3/2 units, and a linear structure (A2) including repeated R22SiO2/2 units, wherein R1 is a propyl group and each R2 is an independently selected substituted or unsubstituted hydrocarbyl group, and wherein the resinous structure (A1) and the linear structure (A2) are bonded together in the silicone resin-linear copolymer via a siloxane bond.

Abstract: Described are hydrosilylation-curable polyorganosiloxane compositions containing sulfur, including hydrosilylation-curable polyorganosiloxane prepolymers and hydrosilylation-cured polyorganosiloxane polymer products made therefrom, as well as methods of preparing and using the same, devices comprising or prepared from the same, and sulfur-functional organosiloxanes useful therein.

Abstract: The present disclosure provides methods of making organosiloxane polymer compositions from hydrosilylation curable compositions comprising at least the components (a) and (b) and at least one of components (c) and (d): (a) an organosiloxane resin material comprising aliphatic unsaturation; and (b) an organosiloxane crosslinker comprising multiple silicon atom-bonded hydrogen atoms (e.g., an “SiH siloxane”); in combination with at least one of (c) at least one organosiloxane comprising at least two silicon atom-bonded hydrogen atoms; and (d) at least one organosiloxane comprising at least two silicon atom-bonded hydrocarbyl groups comprising aliphatic unsaturation (e.g., a “di-vinyl functional siloxane”). Such hydrosilylation curable compositions have, in some instances, significantly faster cure speed, relative to their condensation curable counterparts.

Abstract: The various embodiments of the present invention relate to condensation curable silicone compositions comprising: a condensation curable polyorganosiloxane; and treated particles comprising a particulate solid having an effective amount of nitrogen-containing base (e.g., a nitrogen-containing superbase) disposed thereon. Other embodiments of the present invention relate to methods for preparing the aforementioned treated particles; the treated particles themselves; and methods of using the treated particles and compositions of the various embodiments of the present invention.

Abstract: An optical assembly includes an optical device having an optical surface. The optical assembly further includes an encapsulant that substantially covers the optical surface. The encapsulant has a first layer (106) and a second layer (108). The first layer (106) has a first silicone-containing hot melt composition and a major surface (112). The second layer (108) has a second silicone-containing hot melt composition, the second layer (108) having a second major surface (110) in contact with the first major surface (112).

Abstract: The present disclosure relates to a method of making an optical assembly. An optical device is secured in a fixture, the optical device having an optical surface, wherein a silicone film is positioned with respect to the optical surface, the silicone film having a distal surface relative to the optical surface. The method includes, among other features, imprinting the distal surface of the silicone film to create a surface imprint in the distal surface of the silicone film.

Abstract: Adhesive compositions are disclosed. In some embodiments, the adhesive compositions comprise an organosiloxane block copolymer, wherein the blocks of the block copolymer consist of an —Si—O—Si— backbone. The organosiloxane block copolymer comprises at least two blocks that are phase-separated. The organosiloxane block copolymer has at least a first glass transition temperature (Tg1) and a second glass transition temperature (Tg2), the second glass transition temperature being at 25° C. or higher. A 1 mm thick cast film of the adhesive composition has, in some embodiments, a light transmittance of at least 95%. The adhesive composition of the various embodiments of the present invention can be B-staged at about Tg2 or at about 100° C. below Tg2.

Abstract: Described are hydrosilylation-curable polyorganosiloxane compositions containing sulfur, including hydrosilylation-curable polyorganosiloxane prepolymers and hydrosilylation-cured polyorganosiloxane polymer products made therefrom, as well as methods of preparing and using the same, devices comprising or prepared from the same, and sulfur-functional organosiloxanes useful therein.

Abstract: The present disclosure provides hydrosilylation curable compositions comprising resin linear organosiloxane block copolymers comprising, among other things, from about 0.5 to about 5 mole % C1 to C30 hydrocarbyl group comprising at least one aliphatic unsaturated bond. Such hydrosilylation curable resin-linear organosiloxane block copolymers have significantly faster cure speed, relative to their condensation curable counterparts. A faster cure speed can be important for encapsulating electronic devices, such as light-emitting diode (LED) chip devices, particularly devices having tall structures.

Abstract: An optical article includes a silicone-containing composition. The silicone composition includes a first region having a first refractive index and a second region having a second refractive index. The first refractive index is different than the second refractive index.