Abstract: Provided is a curable silicone composition which exhibits a practically effective pot life, is curable at a low temperature, and which can be used to form a cured product that has superior surface smoothness, is transparent, and has high hardness. This curable silicone composition contains: (A) a resinous alkenyl group-containing organopolysiloxane having, per molecule, at least two alkenyl groups and at least one aryl group; (B) a resinous organohydrogenpolysiloxane having, in one molecule, at least two hydrogen atoms bonded to silicon atoms; (C) a molecular chain side chain polyether-modified organopolysiloxane, a phenyl-modified organopolysiloxane, a non-terminal hydroxyl group-containing dimethyl polysiloxane that does not contain an aryl group, and a phenolic antioxidant, as well as an adhesive that has a wettability improvement effect and is selected from a combination of these; and (D) a curing reaction inhibitor.

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 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 curable silicone composition is disclosed. The curable silicone composition comprises: (A) a linear organopolysiloxane having at least two silicon atom-bonded alkenyl groups per molecule, wherein at least 5 mole % of all silicon atom-bonded organic groups are aryl groups; (B) an organopolysiloxane containing siloxane units represented by the general formula R13SiO1/2 where each R1 represents an independently selected monovalent hydrocarbon group, and siloxane units represented by the general formula SiO4/2, wherein the amount of alkenyl groups is at least 6% by weight; (C) an organopolysiloxane having at least two silicon atom-bonded hydrogen atoms per molecule; and (D) a hydrosilylation reaction catalyst. The curable silicone composition forms a cured product with little weight reduction, little change in hardness, and little crack generation after thermal aging.

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 silicone composition is disclosed. The curable silicone composition comprises: (A) a linear organopolysiloxane having at least two silicon atom-bonded alkenyl groups per molecule, wherein at least 5 mole % of all silicon atom-bonded organic groups are aryl groups; (B) an organopolysiloxane containing siloxane units represented by the general formula R13SiO1/2 where each R1 represents an independently selected monovalent hydrocarbon group, and siloxane units represented by the general formula SiO4/2, wherein the amount of alkenyl groups is at least 6% by weight; (C) an organopolysiloxane having at least two silicon atom-bonded hydrogen atoms per molecule; and (D) a hydrosilylation reaction catalyst. The curable silicone composition forms a cured product with little weight reduction, little change in hardness, and little crack generation after thermal aging.

Abstract: A co-modified organopolysiloxane having a viscosity at 25° C. of not more than 1,500 mPa·s, a group that has a siloxane dendron structure, a hydrophilic group, and expressed by the following general formula (1): R1aR2bL1cQdSiO(4-a-b-c-d)/2 (1). The invention also relates to a powder treatment agent, a powder in oil dispersion, an external use preparation (particularly a cosmetic composition) composition comprising the co-modified organopolysiloxane. In said general formula (1), R1 is a monovalent hydrocarbon group or a hydrogen atom; R2 is a monovalent hydrocarbon group having from 6 to 30 carbons; L1 is a silylalkyl group having a siloxane dendron structure; and Q is a hydrophilic segment.

Abstract: The present invention provides a novel organopolysiloxane in which a rich hydrophilic property is exhibited, not only superior miscibility with a hydrophilic component and but also a hydrophobic property are exhibited, and superior miscibility with both a silicone oil and a non-silicone oil such as a hydrocarbon oil, an ester oil or the like, and provide various usages of the aforementioned novel organopolysiloxane by developing the superior characteristics thereof such as good surface activity power, a distinctive sensation during use, increased stability and the like. A co-modified organopolysiloxane having a specified chemical structure in which a sugar alcohol-modified group and a long-chain hydrocarbon group are present in one molecule is produced.

Abstract: A curable silicone composition comprising: (A) an organopolysiloxane represented by the average unit formula: (R13SiO1/2)x(R22SiO2/2)y(R3SiO3/2)z (R1 are alkyl groups, alkenyl groups, aryl groups, or aralkyl groups; R2 are alkyl groups or alkenyl groups; R3 is an alkyl group, aryl group, or an aralkyl group, provided that, in a molecule, at least 0.5 mol % of R1 to R3 are the alkenyl groups, at least one of R3 is the aryl group or the aralkyl group; and x, y and z are numbers satisfying: 0.01?x?0.5, 0.01?y?0.4, 0.1?z?0.9, and x+y+z=1); (B) a straight-chain organopolysiloxane having at least two alkenyl groups in a molecule; (C) an organopolysiloxane having at least two silicon atom-bonded hydrogen atoms in a molecule; and (D) a hydrosilylation reaction catalyst. A cured product exhibiting excellent dispersibility of phosphor and having crack resistance is formed.

Abstract: The present invention relates to a curable silicone composition comprising: (A) an organopolysiloxane represented by the average unit formula: (R13SiO1/2)a(R12SiO2/2)b (R2SiO3/2)c (R3SiO3/2)d, wherein, R1 are the same or different alkyl groups having from 1 to 12 carbons, alkenyl groups having from 2 to 12 carbons, aryl groups having from 6 to 20 carbons, or aralkyl groups having from 7 to 20 carbons, provided that at least two R1 in a molecule are the alkenyl groups; R2 is an aryl group having from 6 to 20 carbons or an aralkyl group having from 7 to 20 carbons; R3 is an alkyl group having from 1 to 12 carbons; and a, b, c, and d are respectively numbers satisfying: 0.01?a?0.5, 0?b?0.7, 0.01?c<0.7, 0.1?d<0.9, and a+b+c+d=1; (B) a linear organopolysiloxane having at least two silicon-bonded alkenyl groups and at least one silicon-bonded aryl group in a molecule; (C) an organopolysiloxane having at least two silicon-bonded hydrogen atoms in a molecule; (D) a hydrosilylation-reaction catalyst.

Abstract: A surface treatment agent or a powder treatment agent comprising a co-modified organopolysiloxane is disclosed. The co-modified organopolysiloxane is represented by the general formula: R1aR2bQcSiO(4?a?b?c)/2. The co-modified organopolysiloxane has a number average molecular weight of less than 4500 and includes a long-chain alkyl group and a polyoxyalkylene group in the molecule.

Abstract: The present invention provides a curable silicone composition for forming a cured product which inhibits the discoloration of silver electrodes or a silver-plated substrate in an optical semiconductor device due to a sulfur-containing gas, the curable silicone composition comprising: (A) an organopolysiloxane having at least two silicon-bonded alkenyl groups per molecule; (B) an organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms per molecule; (C) an organic compound having an organic value of at least 175 in an organic conceptual diagram and having a specific group; and (D) a hydrosilylation reaction catalyst. In addition, the present invention provides an optical semiconductor device in which silver electrodes or a silver-plated substrate of an optical semiconductor device is sealed or covered with a cured product of the composition described above, the optical semiconductor device having excellent reliability after a sulfur resistance test.

Abstract: Problem: To provide a novel copolymer capable of use as a surface treatment agent which is safe and does not generate hydrogen, which has good compatibility with other cosmetic raw materials so as to be able to improve compounding stability of a cosmetic, which contributes to good water resistance, sebum resistance, gloss, feel, hair attachment ability, skin attachment ability and the like of a cosmetic, which further may be used for treatment of powders of a wide range of cosmetics, and which nearly entirely suppresses the occurrence of dispersion failure on the skin. Resolution Means: A copolymer comprising: (A) an unsaturated monomer having a carbosiloxane dendrimer structure; and (B) an unsaturated monomer having at least one hydrophilic group in the molecule. A content of the unsaturated monomer having the carbosiloxane dendrimer structure is in the range of 35 to 50% by mass of the total monomer units of the copolymer.

Abstract: A curable silicone composition comprising: (A) an organopolysiloxane represented by the average unit formula: (R13SiO1/2)a(R22SiO2/2)b(R3SiO3/2)c (R1 are alkyl groups, alkenyl groups, aryl groups, or aralkyl groups; R2 are alkyl groups or alkenyl groups; R3 is an alkyl group, aryl group, or an aralkyl group, provided that, in a molecule, at least 0.5 mol % of R1 to R3 are the alkenyl groups, at least one of R3 is the aryl group or the aralkyl group; and a, b, and c are numbers satisfying: 0.01?a?0.5, 0.4?b?0.8, 0.01?c?0.5, and a+b+c=1); (B) an organopolysiloxane that is different from component (A); (C) an organopolysiloxane having at least two silicon atom-bonded hydrogen atoms in a molecule; and (D) a hydrosilylation reaction catalyst. A cured product exhibiting excellent dispersibility of phosphor and having high strength and gas barrier properties is formed.

Abstract: An excellent oil-thickening or -gelling agent is provided. The agent is compatible with various oils and can freely control the form or viscosity of oily raw materials or cosmetics by changing the quantity thereof added. The agent contains a novel co-modified organopolysiloxane that contains both a group having a siloxane dendron structure and a hydrophilic group and that preferably has a degree of polymerization of 200 or more. A gel composition containing the co-modified organopolysiloxane is also provided. The gel composition is useful as a base that permits stable and easy preparation of cosmetics having various viscoelasticities and forms. An oil is kept in the form of a gel that has a viscoelasticity falling within the intermediate range between the viscoelasticity of liquid and that of solid. Cosmetics containing the thickening or gelling agent are also provided.

Abstract: A curable silicone composition comprising: (A) an organopolysiloxane represented by the average unit formula: (R13SiO1/2)x(R22SiO2/2)y(R3SiO3/2)z (R1 are alkyl groups, alkenyl groups, aryl groups, or aralkyl groups; R2 are alkyl groups or alkenyl groups; R3 is an alkyl group, aryl group, or an aralkyl group, provided that, in a molecule, at least 0.5 mol % of R1 to R3 are the alkenyl groups, at least one of R3 is the aryl group or the aralkyl group; and x, y and z are numbers satisfying: 0.01?x?0.5, 0.01?y?0.4, 0.1?z?0.9, and x+y+z=1); (B) a straight-chain organopolysiloxane having at least two alkenyl groups in a molecule; (C) an organopolysiloxane having at least two silicon atom-bonded hydrogen atoms in a molecule; and (D) a hydrosilylation reaction catalyst. A cured product exhibiting excellent dispersibility of phosphor and having crack resistance is formed.

Abstract: A curable silicone composition comprising: (A) an organopolysiloxane represented by the average unit formula: (R13SiO1/2)a(R22SiO2/2)b(R3SiO3/2)c (R1 are alkyl groups, alkenyl groups, aryl groups, or aralkyl groups; R2 are alkyl groups or alkenyl groups; R3 is an alkyl group, aryl group, or an aralkyl group, provided that, in a molecule, at least 0.5 mol % of R1 to R3 are the alkenyl groups, at least one of R3 is the aryl group or the aralkyl group; and a, b, and c are numbers satisfying: 0.01?a?0.5, 0.4?b?0.8, 0.01?c?0.5, and a+b+c=1); (B) an organopolysiloxane that is different from component (A); (C) an organopolysiloxane having at least two silicon atom-bonded hydrogen atoms in a molecule; and (D) a hydrosilylation reaction catalyst. A cured product exhibiting excellent dispersibility of phosphor and having high strength and gas barrier properties is formed.

Abstract: The present invention provides a co-modified organopolysiloxane having a specified chemical structure in which a sugar alcohol-modified group and a silylalkyl group having a siloxane dendron structure, and optionally a long-chain hydrocarbon group are present. The co-modified organopolysiloxane is blended, as a surfactant, a powder treatment agent, a gelling agent or the like, or as a cosmetic raw material together with powder (s), oil agent (s) or the like, in a preparation for external use, and in particular, a cosmetic.