Abstract: The present disclosure provides a curable silicone composition comprising: (A) at least one resinous organopolysiloxane having at least two alkenyl groups and at least one aryl group per molecule; (B) at least one organohydrogen polysiloxane having at least two silicon-bonded hydrogen atoms per molecule; (C) at least one inorganic filler having a reflective index of 1.50 or higher; (D) two or more polyether-modified organopolysiloxane comprising a combination of (d-1) at least one polyether-modified organopolysiloxane having at least one terminal —OH group in a polyether chain, and (d-2) at least one polyether-modified organopolysiloxane having at least one terminal alkoxy or acyloxy group in a polyether chain; and (E) at least one hydrosilylation catalyst. A sealing material formed from the curable silicone composition, and an optical semiconductor device comprising the sealing material are also disclosed.

Abstract: Curable silicone compositions, encapsulants including the same, and optical semiconductor devices including the encapsulants are provided herein. In an embodiment, a curable silicone composition includes: (A) an alkenyl group-containing organopolysiloxane having at least two alkenyl groups per molecule; (B) an organohydrogenpolysiloxane having at least two silicon atom-bonded hydrogen atoms per molecule; (C) an epoxy group-containing resinous organopolysiloxane represented by Average Unit Formula (I): (R13SiO1/2)f(R22SiO2/2)g(R1SiO3/2)h(SiO4/2)i(XO1/2)j wherein R1 are independently halogen-substituted or unsubstituted monovalent hydrocarbon groups, at least two R1 are alkenyl groups; R2 are independently halogen-substituted or unsubstituted monovalent hydrocarbon groups or epoxy group-containing organic groups, wherein at least one R2 is an epoxy group-containing organic group; X is a hydrogen atom or an alkyl group; 0?f<1; 0<g<1; 0?h<0.9; 0?i<0.5; and 0<j<0.5; f+g+h+i+j=1.

Abstract: A curable silicone composition comprises (A) a resinous alkenyl group-containing organopolysiloxane including at least two alkenyl groups per molecule and at least one (SiO4/2) unit, (B) a resinous organohydrogenpolysiloxane including at least two silicon atom-bonded hydrogen atoms per molecule and at least one (SiO4/2) unit, (C) a catalyst for hydrosilylation reaction, and (D) a curing reaction inhibitor. The curable silicone composition exhibits practically effective curability even at low temperatures, has a low shape deformation and shrinkage rate during curing, can be cured in a short period of time, and can form a transparent and high-hardness cured product.

Abstract: A curable silicone composition is capable of forming a cured product having excellent elongation characteristics. The curable silicone composition, comprises: (A) a resinous alkenyl group-containing organopolysiloxane containing less than two alkenyl groups per molecule on average, which is represented by average unit formula (I): (R13SiO1/2)a(R12SiO2/2)b(R1SiO3/2)c(SiO4/2)d(XO1/2)e, where in formula (I), each R1 is independently a monovalent hydrocarbon group including an alkenyl group, while the number of alkenyl groups per molecule is less than two on average, X is a hydrogen atom or an alkyl group, 0?a?1, 0?b?1, 0?c<0.9, 0?d<0.5, 0?e<0.4, a+b+c+d=1.0, and c+d>0; (B) an organohydrogenpolysiloxane having two or more silicon atom-bonded hydrogen atoms per molecule; and (C) a curing reaction catalyst.

Abstract: A UV curable silicone composition has exceptional curability by ultraviolet irradiation.

Abstract: An optical member resin sheet has excellent characteristics as an optical member and exhibits excellent performance even if used for a light-emitting device or the like. The optical member resin sheet is characterized in that the difference between the thickness of an end of the sheet and the thickness of the center of the sheet in the width direction of the sheet is within 5.0% of the total film thickness of the sheet; in that the thickness of the center of the sheet is in the range of 10-1000 ?m; in that the sheet area is 225 mm2 or more; and by containing at least one fluorescent substance or reflective material.

Abstract: A Curable Silicone Composition, Encapsulant And Optical Semiconductor Device provides a curable silicone composition having excellent storage stability at room temperature. A curable silicone composition having (A) a resinous alkenyl group-containing organopolysiloxane including at least two alkenyl groups per molecule and at least one siloxane unit represented by SiO4/2; (B) an organohydrogenpolysiloxane having at least two silicon atom-bonded hydrogen atoms in one molecule; (C) an alkyne group-containing compound; and (D) a curing catalyst, wherein the content of the resinous alkenyl group-containing organopolysiloxane (A) is 20 mass % or more based on the total mass of the organopolysiloxane components.

Abstract: Hotmelt silicone compositions are provided including: (A) a resinous alkenyl group-containing organopolysiloxane component, in which the silicon atom-bonded organic groups do not include an epoxy group-containing organic group, wherein the resinous alkenyl group-containing organopolysiloxane component includes (A-1) a resinous alkenyl group-containing organopolysiloxane including at least two alkenyl groups per molecule and free from a (Ar2SiO2/2) unit, and (A-2) a resinous alkenyl group-containing organopolysiloxane including at least two alkenyl groups per molecule and at least one (Ar2SiO2/2) unit; (B) an organohydrogenpolysiloxane having at least two silicon atom-bonded hydrogen atoms per molecule; and (C) a curing catalyst. The resinous alkenyl group-containing organopolysiloxane (A-1) is included in an amount of about 5 mass % or more based on the total mass of all the organopolysiloxane components in the hotmelt silicone composition.

Abstract: A UV curable silicone composition has exceptional curability by ultraviolet irradiation.

Abstract: A silicone grease composition is disclosed. The grease composition contains a silicone oil and zinc dialkyldithiocarbamate as an extreme-pressure additive. The grease composition contains substantially no zinc dialkyldithiophosphate. The grease composition achieves high friction characteristics and wear characteristics. A method for transmitting torque of a clutch or a torque limiter mechanism is also disclosed. Moreover, a method for producing a clutch or a torque limiter mechanism is disclosed. The methods utilize the aforementioned grease composition.

Abstract: Disclosed is a method of making an optoelectronic device that incorporates a crosslinked resin-linear polyorganosiloxane.

Abstract: A curable silicone composition encapsulates, coats, or adheres an optical semiconductor element. The curable silicone composition can form a cured product with sufficiently low gas-permeability, and with little weight decrease and little change in hardness even on long-term exposure to high temperatures. The curable silicone composition comprises resinous organopolysiloxane that contains at least one (Ar2SiO2/2) unit, wherein Ar denotes an aryl group.

Abstract: A curable white silicone composition that is capable of forming a cured product having a high optical reflectance as well as exceptional light resistance is provided. The curable white silicone composition includes (A) an organopolysiloxane having at least 2 alkenyl groups per molecule, (B) a cerium-containing organopolysiloxane, (C) a white pigment, and (D) a curing catalyst.

Abstract: A white curable silicone composition provides excellent elongation characteristics while providing sufficiently great hardness, which as a result can provide a cured product having excellent toughness. The composition comprises: (A) alkenyl group-containing resinous organopolysiloxane which is represented by an average composition formula: (R13SiO1/2)a(R12SiO2/2)b(R1SiO3/2)c(SiO4/2)d(XO1/2)e, where, in the formula, R1 are each independently a monovalent hydrocarbon group, while at least two R1 are alkenyl groups, X is a hydrogen atom or an alkyl group, 0?a?0.7, 0?b?0.2, 0?c?0.3, 0?d?0.8, and 0?e?0.2, a+b+c+d=1.

Abstract: A silicone grease composition having high friction characteristics and wear characteristics is disclosed. The silicone grease composition is provided by adding a zinc salt (B) containing, at a mass ratio from 1:99 to 99:1, a zinc dialkyldithiophosphate (B1) and a zinc dialkyldithiocarbamate (B2) as an extreme-pressure additive to a silicone oil (A). A method for transmitting torque of a clutch or a torque limiter mechanism is also disclosed.

Abstract: A curable silicone composition for die bonding use contains at least (A) an organopolysiloxane having at least two alkenyl groups per molecule, (B) an organopolysiloxane having at least two siloxane units each represented by the formula: RHSiO (wherein R represents a monovalent hydrocarbon group having 1 to 12 carbon atoms and having no aliphatic unsaturated bond) per molecule, (C) a platinum-group metal-based catalyst for hydrosilylation reactions, (D) a hydrosilylation reaction inhibitor and (E) an adhesiveness-imparting agent, wherein the scorch time (ts1), which is defined in JIS K 6300-2, at a die bonding temperature is 20 to 60 seconds, and the 90% vulcanization time [tc(90)] with respect to the maximum torque value during the vulcanization time of 600 seconds is 300 to 500 seconds. The curable silicone composition for die bonding use according to the present invention can adhere a semiconductor chip to a support strongly.

Abstract: Curable silicone compositions, encapsulants including the same, and optical semiconductor devices including the encapsulants are provided herein. In an embodiment, a curable silicone composition includes: (A) an alkenyl group-containing organopolysiloxane having at least two alkenyl groups per molecule; (B) an organohydrogenpolysiloxane having at least two silicon atom-bonded hydrogen atoms per molecule; (C) an epoxy group-containing resinous organopolysiloxane represented by Average Unit Formula (I): (R13SiO1/2)f(R22SiO2/2)g(R1SiO3/2)h(SiO4/2)i(XO1/2)j wherein R1 are independently halogen-substituted or unsubstituted monovalent hydrocarbon groups, at least two R1 are alkenyl groups; R2 are independently halogen-substituted or unsubstituted monovalent hydrocarbon groups or epoxy group-containing organic groups, wherein at least one R2 is an epoxy group-containing organic group; X is a hydrogen atom or an alkyl group; 0?f<1; 0<g<1; 0?h<0.9; 0?i<0.5; and 0<j<0.5; f+g+h+i+j=1.

Abstract: A curable hot-melt silicone composition exhibits excellent mechanical properties, particularly strength and extension, even when formed in a film or sheet shape. The curable hot-melt silicone composition contains (A) alkenyl group-containing organopolysiloxane having at least 2 alkenyl groups per molecule, (B) branched organohydrogenpolysiloxane having at least 2 silicon-bonded hydrogen atoms per molecule, at 0.1 to 5% by mass relative to the total mass of the composition, (C) additive represented by average unit formula (C-1), (D) hydrosilylation catalyst, and (E) silica.

Abstract: Hotmelt silicone compositions are provided including: (A) a resinous alkenyl group-containing organopolysiloxane component, in which the silicon atom-bonded organic groups do not include an epoxy group-containing organic group, wherein the resinous alkenyl group-containing organopolysiloxane component includes (A-1) a resinous alkenyl group-containing organopolysiloxane including at least two alkenyl groups per molecule and free from a (Ar2SiO2/2) unit, and (A-2) a resinous alkenyl group-containing organopolysiloxane including at least two alkenyl groups per molecule and at least one (Ar2SiO2/2) unit; (B) an organohydrogenpolysiloxane having at least two silicon atom-bonded hydrogen atoms per molecule; and (C) a curing catalyst. The resinous alkenyl group-containing organopolysiloxane (A-1) is included in an amount of about 5 mass % or more based on the total mass of all the organopolysiloxane components in the hotmelt silicone composition.

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.