Abstract: Blending (A) a diorganopolysiloxane end-blocked with a hydroxyl group, (B) a hydrolyzable silane having ketoxime, alkoxy, acyloxy, amide or amino groups or a partial hydrolyzate thereof, (C) an organic compound having a C═O group, and (D) an organic compound having a NH2 group gives a condensation curing type composition which is fast and deeply curable at room temperature.

Abstract: A room temperature curable organopolysiloxane composition including: (A) 100 parts by weight of a diorganopolysiloxane represented by the general formula (1):HO?Si(R.sup.1).sub.2 O!.sub.n H (1)wherein R.sup.1 represents a substituted or unsubstituted monovalent hydrocarbon group, and n is an integer of 15 or more;(B) from 0.1 part by weight to 20 parts by weight of an organosilane, or a partially hydrolyzed product thereof, represented by the general formula (2):(R.sup.2).sub.m S(OR.sup.2).sub.4-m (2)wherein R.sup.2 's each independently represent a substituted or unsubstituted monovalent hydrocarbon group, and m is 0, 1 or 2;(C) from 0.01 part by weight to 10 parts by weight of a curing catalyst;(D) from 20 parts by weight to 600 parts by weight of a magnesium silicate; and(E) from 5 parts by weight to 80 parts by weight of a paraffin type aliphatic hydrocarbon which is liquid or semi-solid at room temperature. This composition can be rapidly cured, even after a long-term storage.

Abstract: A platinum catalyst containing (A) a platinum complex having a vinyl-containing organosiloxane ligand and (B) a vinyl-containing organopolysiloxane is prepared by mixing components (A) and (B) such that at least 2 mol of vinyl group in component (B) is available per mol of platinum atom in component (A) and heating the mixture at 40.degree.-100.degree. C. for at least 1 hour. When blended in an addition reaction curing type organosiloxane composition, the platinum catalyst has the advantage that even after long-term storage at elevated temperatures, it remains stable and active enough to cause the organosiloxane composition to cure.

Abstract: The present invention relates to a soft lining material composition for dentures, which comprises, at specific ratios, an organopolysiloxane having a specific structure and a viscosity lying in a specific range, an organohydrogenpolysiloxane having another specific structure, a platinum compound soluble in silicone, a finely divided silica having a BET specific surface area lying in a specific range and subjected to a hydrophobic treatment on the surface, and a molten quartz powder having an average particle size lying in a specific range, such soft lining material composition providing a cured soft lining material composition which undergoes a little hardness change upon inserted in the mouth over an extended period of time, does not separate away from a denture, and being satisfactory in terms of the ability to be cut and polished.

Abstract: The invention involves a silicone gel composition comprising (A) 100 parts by weight of an organopolysiloxane of average compositional formula (1):R.sup.1.sub.a R.sup.2.sub.b SiO.sub.(4-a-b)/2 (1)wherein R.sup.1 is an alkenyl group: R.sup.2 is an optionally substituted, monovalent hydrocarbon group without an aliphatic unsaturated bond and the subscripts a and b are positive numbers 0<a<3, 0<b<3, and 1<a+b<3,(B) 0.05 to 10 parts by weight of an organosiloxane oligomer having alkenyl groups bound to silicon atoms only at the terminal ends of the molecule and at least three such alkenyl groups per molecule,(C) an organohydrogen polysiloxane having at least two hydrogen atoms bound to silicon atoms per molecule, and(D) a catalytic amount of an addition reaction catalyst. The invention also involves electronic materials coated therewith.

Abstract: A gel-forming silicone composition comprising (A) an organopolysiloxane containing a silicon-bonded alkenyl group or groups in an average amount of from 0.15 to 0.35 mol % based on all silicon-bonded organic groups contained per molecule, (B) a non-functional organopolysiloxane, (C) an organohydrogenpolysiloxane containing an average of 2 silicon-bonded hydrogen atoms per molecule, and (D) an addition reaction catalyst. The silicone composition is able to give a gel-like cured silicone product with low modulus of elasticity while retaining flexibility.

Abstract: A silicone gel composition comprising (A) a linear organopolysiloxane having a backbone consisting only of trifluoropropyl-substituted siloxane units and terminated with alkenyl group, (B) an organohydrogenpolysiloxane, (C) a platinum catalyst, and (D) a finely powdered silica whose surfaces have been rendered hydrophobic by treatment with a silicon compound having only methyl groups as substituent groups, such as hexamethyldisilazane, trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane, trimethylalkoxysilane, dimethyldialkoxysilane, methyltrialkoxysilane and cyclic or linear dimethylpolysiloxanes. The composition has good thixotropy and can effectively provide a protective layer by spot potting. The silicone gel formed from the composition is excellent in solvent resistance, etc. and is effectively restrained from shrinkage or the like. Therefore the composition is highly suited to use as a protective material for semiconductor-type pressure sensors.

Abstract: A silicone composition is of the addition reaction type which comprises a vinyl group-containing organopolysiloxane, an organohydrogenpolysiloxane which has at least one hydrogen atom joined to a silicon atom in one molecule, a platinum group metal catalyst, and an aluminum oxide powder which is substantially round or spherical in shape with an average particle size of not larger than 50 .mu.m and wherein when the aluminum oxide powder is subjected to extraction of alkali metal ions and halogen ions under conditions of 121.degree. C., 2 atmospheric pressures, 100% R.H. and 20 hours, the contents of both ions are, respectively, not larger than 5 ppm. The cured product obtained from the composition has high thermal conductivity and the composition is useful as a sealant of electric and electronic parts and can prevent the parts from being corroded.

Abstract: To a silicone composition comprising (A) an organopolysiloxane having at least two alkenyl groups in a molecule, (B) an organohydrogenpolysiloxane having at least two hydrogen atoms each directly attached to a silicon atom in a molecule, and (C) a platinum catalyst, (D) a compound having a phenyl group and a secondary or tertiary amino group directly attached thereto is added to render the composition flame retardant. The composition cures into a transparent product having improved flame retardancy meeting the UL standard and is suitable for use in the protection of electronic parts like ICs and hybrid ICs.

Abstract: An adhesive silicone composition comprising (A) an alkenyl group-containing organopolysiloxane, (B) an organohydrogen-polysiloxane having at least three hydrogen atoms each directly bonded to a silicon atom in a molecule, (C) a compound having at least one aliphatic unsaturated group and at least two phenyl skeletons in a molecule, and (D) a platinum catalyst is well adhesive to both metals and reins, and even to difficult-to-adhere resins such as nylon, polycarbonate and acryl resins.

Abstract: A gel-forming silicone composition comprising, compounded in a gel-forming base composition, a silane compound having the following general formula (1) or (2): ##STR1## wherein R.sup.1 is an alkyl or aryl group, R.sup.2 is an alkyl or alkoxyalkyl group, R.sup.3 and R.sup.4 are each a hydrogen atom, a methyl group or an ethyl group, R.sup.5 is an alkyl group or an ester linkage-containing group, and a, b and n are each an integer from 0 to 2. The composition is capable of forming, under mild conditions, a silicone gel which exhibits good adherence to a variety of substrates.

Abstract: A process for producing a branched organopolysiloxane, comprising the steps of subjecting mixture of (A) a trialkoxysilane having the general formula (1):R.sup.1 Si(OR.sup.2).sub.3 (1)wherein R.sup.1 is a hydrocarbon group, and R.sup.2 are each a hydrocarbon group, and (B) an organosiloxane oligomer obtained by hydrolysis-condensation of a silane compound having the general formula (2):R.sup.3.sub.a SiCl.sub.4-a (2)wherein R.sup.3 are each a hydrocarbon group and a is 2 or 3, to equilibration reaction in the presence of an alkali catalyst, and adding water, subsequently to or concurrently with the equilibration reaction, to the reaction mixture, thereby hydrolyzing the Si--OR.sup.2 groups contained in the organopolysiloxane resulting from the hydrolysis-condensation. A branched organopolysiloxane stable in molecular composition and properties such as viscosity, can be produced.

Abstract: An addition-curable type silicone rubber composition comprising (A) an organopolysiloxane having an alkenyl group such as vinyl in its molecule, (B) an organohydrogenpolysiloxane having at least two SiH groups in its molecule, (C) a platinum catalyst such as platinum, chloroplatinic acid, etc., (D) an inorganic filler, (E) an organic titanium compound such as tetraethyl titanate, and (F) water. The composition exhibits good fluidity, and behaves like a Newtonian fluid, even where carbon black or a silica or alumina having an average particle diameter of 1 .mu.m or above is incorporated in the composition as an inorganic filler for improving such characteristics as heat resistance, thermal conductivity, etc.

Abstract: An addition-curing type organopolysiloxane composition comprising, in addition to an alkenyl-containing organopolysiloxane and an organohydrogenpolysiloxane, an amine compound represented by the general formula:(R.sup.2).sub.2 N--R.sup.4 --N(R.sup.3).sub.2wherein R.sup.2 is an alkyl radical of from 1 to 4 carbon atoms, R.sup.3 is an alkyl radical of from 1 to 4 carbon atoms or a hydrogen atom, and R.sup.4 is an alkylene radical of from 2 to 4 carbon atoms, or an amine compound represented by the general formula:R.sup.5 --NH.sub.2wherein R.sup.5 is an alkyl radical of from 2 to 4 carbon atoms, and acetylene alcohol. The composition has excellent long-time shelf stability at room temperature and, when heated, rapidly cures to yield a gel form or elastomer form cured product.

Abstract: The present organopolysiloxane composition comprises (A) an organopolysiloxane in which 5 to 30 mol % of the molecule ends is made up of an (R.sup.1).sub.3 Si.sub.0.5 unit and 95 to 70 mol % of the molecule ends is made up of at least one unit selected from the group consisting of an R.sup.1 (R.sup.2).sub.2 SiO.sub.0.5 unit, an (R.sup.1).sub.2 R.sup.2 SiO.sub.0.5 unit, and an (R.sup.2).sub.3 SiO.sub.0.5 unit, in which units R.sup.1 represent a vinyl group and R.sup.2 represents a hydrocarbon group excluding aliphatic unsaturated groups, (B) an organohydrogenpolysiloxane having two or more Si--H groups in the molecule, and (C) an addition reaction catalyst. By curing this composition, a gel cured product having high resistance to poisoning by solder fluxes can be obtained.

Abstract: The present fluorosilicone composition is an addition reaction curable composition that uses, as an alkenyl group-containing organopolysiloxane, a fluorine-containing organopolysiloxane represented by the following general formula (1): ##STR1## wherein R represents a vinyl group, R.sup.1 represents an alkyl group or a phenyl group, R.sup.2 represents a group represented by the following formula (2): ##STR2## in which p is an integer of 2 to 8 and q is an integer of 1 to 10, and n and m are each a positive integer. This composition can form a gellike cured product particularly excellent in acid resistance.

Abstract: The silicone composite product comprises a silicone gel obtained by curing a specified addition-curable type organopolysiloxane composition, and an elastomer layer or resin layer formed on the silicone gel by use of an organopolysiloxane having Si-bonded alkenyl groups and Si-bonded hydrogen atoms. The silicone composite product has the elastomer layer or resin layer formed integrally with the silicone gel phase, whereby such problems as adhesion of dust or refuse to the surface of the silicone gel, etc. can be solved effectively.

Abstract: A curable silicone composition which can cure using hydrosilylation, comprising an aluminum oxide powder and/or silica powder, the powders each consisting of substantially spherical particles with an average particle diameter of 50 .mu.m or below and an elongation of from 1.0 to 1.4 and being such that the respective amounts of alkali metal ions and halogen ions are extracted with 50 ml of water from 5 g of the powder at 121.degree. C. for 20 hours are not more than 10 ppm, wherein the amount of the component (D) is from 25 to 90% by weight based on the composition, and the ratio of the amount of hydrosilyl groups contained in the components (A) and (B) to the amount of alkenyl groups contained in the components (A) and (B) is in the range from 0.5/1 to 1.5/1. When the composition is used as a protective material or encapsulating material for devices such as ICs, generated heat can be dissipated efficiently and the devices are not be broken by abrasion. There are no fears of causing corrosion of the devices.

Abstract: A silicone composition comprising, as the base component to provide crosslinking points, an organopolysiloxane copolymer comprising diorganosiloxane blocks and trifunctional arylsiloxane blocks and the molecular ends of which are terminated with alkenylsiloxy units. This base component is combined with an organohydrogenpolysiloxane and an addition reaction catalyst. This silicone composition can be hardened to produce a highly elastic and damping material which makes an ideal damping and earthquake-resistant structure.

Abstract: An organopolysiloxane composition, comprising(A) an organopolysiloxane having alkenyl groups bonded to silicon atoms,(B) an organohydrogenpolysiloxane having two or more hydrogen atoms bonded to silicon atoms, and(C) an addition reaction catalyst, wherein the vinyl group containing organopolysiloxane (A) as a base polymer and the organohydrogenpolysiloxane (B) as a crosslinking agent each have at least two alkoxy group and/or at least one epoxy group in the molecule. By subjecting this composition to addition curing, a gel cured product excellent in adhesion particularly to metals is obtained.