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 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: 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: 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 silicone composition comprises: (A) an organopolysiloxane having at least two alkenyl groups in a molecule; (B) an organopolysiloxane having at least two silicon atom-bonded hydrogen atoms in a molecule and free of a polyether structure; (C) a polyether-modified silicone having a siloxane dendron structure and a polyether structure; and (D) a hydrosilylation reaction catalyst. The curable silicone composition can be used to form an optical semiconductor device having minimal contamination of a case during manufacturing of the optical semiconductor device, good efficiency of light extraction from a light emitting element, and minimal color unevenness or chromaticity deviation. The optical semiconductor device is notable in that a light emitting element is sealed or covered by a cured material of the composition, in addition to having minimal contamination of a case, good efficiency of light extraction, and minimal chromaticity deviation.

Abstract: An organosilicon compound represented by the general formula, a hydrosilylation-curable silicone composition containing the compound as an adhesion promoter, and a semiconductor device having a semiconductor element sealed with a cured product of the composition. To provide a novel organosilicon compound, a curable silicone composition that contains the organosilicon compound as an adhesion promoter, has excellent initial adhesion and adhesion durability to a base material such as an organic resin, and forms a cured product having high light transmittance, and a highly reliable semiconductor device produced using this composition.

Abstract: A curable silicone composition comprising: (A) an organopolysiloxane having at least two alkenyl groups in a molecule; (B) an organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms in a molecule; (C) an adhesion promoter represented by the average unit formula; and (D) a hydrosilylation reaction catalyst. Provided is a curable silicone composition for forming a transparent cured product having high adhesion to a substrate, and an optical semiconductor device having excellent reliability made using the composition.

Abstract: An organosiloxane represented by the following general formula; a curable silicone composition comprising: (A) an organopolysiloxane having at least two alkenyl groups in a molecule; (B) an organohydrogenpolysiloxane having at least two silicon atom-bonded hydrogen atoms in a molecule; (C) an adhesion promoter containing the organosiloxane; and (D) a catalyst for hydrosilylation reaction; and a semiconductor device in which a semiconductor element is encapsulated with a cured product of the composition. A novel organosiloxane, a curable silicone composition that contains the novel organosiloxane as an adhesion promoter and that forms a cured product having excellent adhesion to various base materials, and a semiconductor device that is formed by using the composition and that has excellent reliability are provided.

Abstract: An organosiloxane represented by the following general formula; a curable silicone composition comprising: (A) an organopolysiloxane having at least two alkenyl groups in a molecule; (B) an organohydrogenpolysiloxane having at least two silicon atom-bonded hydrogen atoms in a molecule; (C) an adhesion promoter containing the organosiloxane; and (D) a catalyst for hydrosilylation reaction; and a semiconductor device in which a semiconductor element is encapsulated with a cured product of the composition. A novel organosiloxane, a curable silicone composition that contains the novel organosiloxane as an adhesion promoter and that forms a cured product having excellent adhesion to various base materials, and a semiconductor device that is formed by using the composition and that has excellent reliability are provided.

Abstract: An organosilicon compound represented by the general formula, a hydrosilylation-curable silicone composition containing the compound as an adhesion promoter, and a semiconductor device having a semiconductor element sealed with a cured product of the composition. To provide a novel organosilicon compound, a curable silicone composition that contains the organosilicon compound as an adhesion promoter, has excellent initial adhesion and adhesion durability to a base material such as an organic resin, and forms a cured product having high light transmittance, and a highly reliable semiconductor device produced using this composition.

Abstract: An adhesion promoter represented by the average formula; a curable silicone composition comprising: (A) an organopolysiloxane having at least two alkenyl groups in a molecule, (B) an organohydrogenpolysiloxane having at least two silicon atom-bonded hydrogen atoms in a molecule, (C) the adhesion promoter, and (D) a hydrosilylation reaction catalyst; and a semiconductor device in which a semiconductor element is encapsulated with a cured product of the curable silicone composition. A novel adhesion promoter, a curable silicone composition that contains the adhesion promoter and that forms a cured product having excellent adhesion to various base materials, and an optical semiconductor device that is formed from the curable silicone composition and that has excellent reliability are provided.

Abstract: A curable silicone composition comprising: (A) an organopolysiloxane having at least two alkenyl groups in a molecule; (B) an organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms in a molecule; (C) an adhesion promoter represented by the average unit formula; and (D) a hydrosilylation reaction catalyst. Provided is a curable silicone composition for forming a transparent cured product having high adhesion to a substrate, and an optical semiconductor device having excellent reliability made using the composition.

Abstract: The present invention relates to a curable silicone composition comprising: (A) an organopolysiloxane having at least two alkenyl groups and at least one aryl group in a molecule, (B) an organopolysiloxane having at least two silicon atom-bonded hydrogen atoms in a molecule, (C) an organopolysiloxane having at least one aryl group in a molecule and containing a metal atom selected from the group consisting of V, Ta, Nb and Ce, and (D) a hydrosilylation-reaction catalyst. The present invention can provide the curable silicone composition, which does not develop a crack by thermal aging and further can form a cured material that exhibits less yellowing.

Abstract: The present invention relates to a curable silicone composition comprising: (A) an organopolysiloxane having at least two alkenyl groups and at least one aryl group in a molecule, (B) an organopolysiloxane having at least two silicon atom-bonded hydrogen atoms in a molecule, (C) an organopolysiloxane having at least one aryl group in a molecule and containing a metal atom selected from the group consisting of V, Ta, Nb and Ce, and (D) a hydrosilylation-reaction catalyst. The present invention can provide the curable silicone composition, which does not develop a crack by thermal aging and further can form a cured material that exhibits less yellowing.