Abstract: A silicone rubber composition contains (A) 100 parts by weight of an organopolysiloxane composition of the organic peroxide or addition reaction curing type, (B) 20-400 parts by weight of aluminum hydroxide, and (C) 1-20 parts by weight of an organopolysiloxane of formula (I): R.sup.1.sub.a (OX).sub.b SiO.sub.(4-a-b)/2 wherein R.sup.1 is a monovalent hydrocarbon group, at least 10 mol % of the R.sup.1 groups being phenyl, X is hydrogen or a monovalent hydrocarbon group, a and b are positive numbers satisfying the range: 1.0.ltoreq.a<2.0, 1<a+b.ltoreq.3, and 0.001.ltoreq.b/(a+b).ltoreq.0.8. The composition cures into a silicone rubber having improved high-voltage electrical insulating properties even under humid conditions.

Abstract: A silicone rubber composition is obtained by blending (A) 100 parts by weight of an organopolysiloxane composition of the addition reaction curing type with (B) about 30-400 parts by weight of aluminum hydroxide which has been surface treated with an organosilane or organosilazane substantially free of an aliphatic unsaturated group or a partial hydrolyzate thereof so that the aluminum hydroxide has 0.01-2% by weight of carbon affixed thereto. The composition maintains silicone rubber properties even though it is loaded with large amounts of aluminum hydroxide. It cures into a silicone rubber having improved high-voltage electrical insulating properties and thus suited for use as high-voltage electrical insulators.

Abstract: A silicone rubber composition comprising (A) 100 parts by weight of an organopolysiloxane composition of the organic peroxide or addition curing type, (B) 1-100 parts by weight of finely divided silica, and (C) 30-500 parts by weight of aluminum hydroxide is suitable for use as a high-voltage electrical insulator. The aluminum hydroxide (C) has a water-soluble sodium ion content of up to 0.01% by weight and exhibits pH 6.5-8.0 and an electrical conductivity of up to 50 .mu.s/cm when measured as a 30 wt % water slurry and preferably has been treated to be hydrophobic. The composition cures into a silicone rubber having improved high-voltage electrical insulating properties even under rigorous conditions.

Abstract: A thixotropic agent is blended in a silicone rubber composition comprising an alkenyl radical-containing organopolysiloxane, an organohydrogenpolysiloxane, an addition reaction catalyst, and filler balloons having a specific gravity of 0.01-0.40 and a mean particle size of 1-300 .mu.m. The resulting composition effectively restrains floating and separation of the filler, remains stable and is thus suitable for injection molding.

Abstract: A silicone rubber composition is obtained by blending (A) 100 parts by weight of an organopolysiloxane composition of the organic peroxide or addition reaction curing type, with (B) 30-400 parts by weight of aluminum hydroxide which has been surface treated so as to bear 1.0.times.10.sup.-6 to 2.0.times.10.sup.-4 mol/gram of vinyl groups. The composition does not lose rubber strength even though it is loaded with large amounts of aluminum hydroxide. It cures into a silicone rubber having satisfactory physical properties and improved high-voltage electrical insulating properties and thus suited for use as high-voltage electrical insulators.

Abstract: Proposed is a method for the preparation of a monolithically integrated composite cured body consisting of a part of cured silicone rubber composition and a part of a silicone-epoxy resin composition firmly bonded together without using any primer or adhesive by first curing either one of the compositions in a metal mold and then bringing the other of the compositions into direct contact with the already cured part in the metal mold to be cured thereon. Firm bonding between the parts can be obtained when the silicone rubber composition is of the peroxide-curable or the hydrosilation-curable type and the silicone-epoxy resin composition comprises:(a) a curable epoxy resin;(b) an alkenyl group-containing organopolysiloxane;(c) an organohydrogenpolysiloxane;(d) an organosilicon compound having at least one silanol group in a molecule;(e) an organic aluminum compound such as aluminum benzoate; and(f) a compound of a platinum group metal such as chloroplatinic acid, each in a specified weight proportion.

Abstract: By curing or semi-curing an addition curable silicone resin composition comprising a phenyl-containing organopolysiloxane, placing an addition or peroxide curable silicone rubber composition in close contact with the cured or semi-cured resin, and heat curing the silicone rubber composition, there is prepared a composite material in which silicone resin and silicone rubber are firmly joined together.

Abstract: A cured product of an epoxy resin composition is integrally and firmly joined to a cured product of an organic peroxide--or addition reaction-curable silicone rubber composition to form an integral composite. The integral composite having practically acceptable adhesion force can be simply and briefly produced without using a primer.

Abstract: A novel curable organopolysiloxane-epoxy resin composition, which is capable of giving a cured body having excellent mechanical properties without the problem of adhesion to the metal mold, is proposed. The composition comprises: (a) an epoxy resin; (b) an organopolysiloxane containing vinyl groups; (c) an organohydrogenpolysiloxane as the crosslinking agent of the component (b); (d) a platinum compound as a catalyst for the hydrosilation reaction; and (e) a specific organic aluminum compound, such as tris(acetylacetonato) aluminum, each in a specified proportion.

Abstract: To a heat-curable silicone rubber composition comprising (a) an organopolysiloxane having at least two alkenyl groups in a molecule, (b) an organohydrogenpolysiloxane having at least two hydrogen atoms in a molecule, and (c) a platinum catalyst is added (d) ammonia or an ammonia precursor so that ammonia or ammonia precursor is present in an amount of 10 to 500 parts by weight of nitrogen per million parts by weight of the total of components (a), (b) and (c) in a cured product of the heat-curable silicone rubber composition. The composition cures into a silicone rubber having minimized compression set without a need for secondary vulcanization.

Abstract: By curing either one of an organic peroxide-curable silicone rubber composition and an organic peroxide-curable unsaturated polyester resin composition and then curing the other composition while placing it in close contact with the cured composition, there is obtained a composite material in which an organic peroxide-cured silicone rubber is closely and firmly joined with an organic peroxide-cured unsaturated polyester resin.

Abstract: An organopolysiloxane emulsion composition comprising:a silicone emulsifying agent comprising a compound represented by the general formula (I): ##STR1## wherein a plurality of R.sup.1 may be the same or different and each represent a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms; R.sup.2 represents a divalent hydrocarbon group having 1 to 6 carbon atoms; R.sup.3 represents an atom or group selected from the group consisting of a hydrogen atom, an acetyl group, R.sup.1, and --Si(R.sup.1).sub.3 ; A represents a divalent hydrocarbon group having 1 to 4 carbon atoms; and x and y are numbers of 5.ltoreq.x.ltoreq.50 and 1.ltoreq.y.ltoreq.100, respectively;an organopolysiloxane which is liquid at room temperature; andwater.This emulsion composition can be prepared as either w/o emulsion or o/w emulsion with good stability.

Abstract: A cationic silicone surfactant with excellent surface tension lowering properties and manufacturing method thereof were disclosed. Since a siloxane with a reactive group at one end is used as starting material for production process, the surfactant of the present invention is an AB type block copolymer which has an ideal structure as a surfactant and can exhibit excellent surface tension lowering properties in aqueous systems or solvent systems.

Abstract: An anionic silicone surfactant, with excellent surface tension lowering properties in aqueous and solvent systems, of the general formula ##STR1## wherein each R.sup.1 is an unsubstituted or halogen-substituted monovalent hydrocarbon group of 1-20 carbon atoms or a trialkylsiloxy group of 1-20 carbon atoms; R.sup.2 is an unsubstituted, halogen-substituted or hydroxyl-substituted bivalent hydrocarbon group of 1-10 carbon atoms, or a corresponding hydrocarbon group wherein no more than half of the carbon atoms are replaced by an oxygen atom; M is a Group A alkali metal or NR.sup.3 R.sup.4 R.sup.5 wherein R.sup.3, R.sup.4 and R.sup.5 are a hydrogen atom or a monovalent hydrocarbon group of 1-20 carbon atoms; and .sub.a is a number which lies in the range 0.ltoreq.a.ltoreq.

Abstract: The coated optical fiber of the invention is prepared by providing a coating layer of an ultraviolet-curable organopolysiloxane or a composition comprising the same and irradiating the coating layer with ultraviolet. Specifically, each of the terminal silicon atoms of the organopolysiloxane, which preferably has a linear molecular structure, has two or more ethylenically unsaturated polymerizable groups bonded thereto through an oxygen atom, such as CH.sub.2 .dbd.CHCOOCH.sub.2 CH.sub.2 --, [CH.sub.2 .dbd.C(CH.sub.3)COOCH.sub.2 ].sub.3 C--CH.sub.2 --and (CH.sub.2 .dbd.CHCOOCH.sub.2).sub.2 C(C.sub.2 H.sub.5)CH.sub.2 --. By virtue of this unique molecular structure of the organopolysiloxane, the coating layer is rapidly cured by ultraviolet irradiation to give a cured coating layer exhibiting very low water absorption and small temperature dependency of the Young's modulus at low temperatures.

Abstract: The surface-coated optical fiber of the invention is composed of a fibrous body of a vitreous material, e.g. fused quartz glass, and a coating layer thereon formed of a coating composition comprising an organosiloxane-modified organic polymer, of which the backbone is formed of recurring organic units such as a polybutadiene, an acrylic polymer and the like having modifying pendant groups containing an organosiloxane unit. The workability of the coating composition in the coating application is excellent so that a high uniformity is obtained in the coating layer in comparison with a coating composition comprising an unmodified organic polymer. The coating layer thus formed has a remarkably improved mechanical strength over a coating layer formed of an organopolysiloxane resin alone.

Abstract: The coated optical fiber of the invention is prepared by providing a coating layer of an ultraviolet-curable organopolysiloxane or a composition comprising the same and irradiating the coating layer with ultraviolet. Specifically, each of the terminal silicon atoms of the organopolysiloxane, which preferably has a linear molecular structure, has two or more ethylenically unsaturated polymerizable groups bonded thereto through an oxygen atom, such as CH.sub.2 .dbd.CHCOOCH.sub.2 CH.sub.2 --, [CH.sub.2 .dbd.C(CH.sub.3)COOCH.sub.2 ].sub.3 C--CH.sub.2 -- and (CH.sub.2 .dbd.CHCOOCH.sub.2).sub.2 C(C.sub.2 H.sub.5)CH.sub.2 --. By virtue of this unique molecular structure of the organopolysiloxane, the coating layer is rapidly cured by ultraviolet irradiation to give a cured coating layer exhibiting very low water absorption and small temperature dependency of the Young's modulus at low temperatures.