Abstract: A curable composition comprising (A) an organopolysiloxane having functional groups capable of condensation reaction at both molecular terminals thereof and (B-1) a hydrophobic silica and a hydrophilic silica. A curable composition comprising (A) an organopolysiloxane having functional groups capable of condensation reaction at both molecular terminals thereof and (B-2) a hydrophobic silica, wherein the hydrophobic silica (B-2) is thermally treated together with the organopolysiloxane (A).

Abstract: A room temperature rapid-curable silicone composition is provided which includes (A) an organopolysiloxane terminated with hydroxyl groups, having a viscosity of from 25 mPa·s to 1,000,000 mPa·s at 25° C.; (B) a compound selected from the group consisting of a hydrolyzable silane represented by the following general formula (1): RnSiX4−n  (1) wherein R represents a monovalent hydrocarbon group having 1 to 12 carbon atoms; X represents a compound selected from the group consisting of a ketoxime group, an alkoxyl group, an alkenoxyl group and an acyloxyl group; and n represents an integer of 0 to 2, and a partial hydrolysis-condensation product thereof; and (C) a water-containing wet-process silica having an average particle diameter of 100 &mgr;m or smaller, which is a chief source for feeding water necessary for condensation curing reaction.

Abstract: A curable composition comprising (A) an organopolysiloxane having functional groups capable of condensation reaction at both molecular terminals thereof and (B-1) a hydrophobic silica and a hydrophilic silica. A curable composition comprising (A) an organopolysiloxane having functional groups capable of condensation reaction at both molecular terminals thereof and (B-2) a hydrophobic silica, wherein the hydrophobic silica (B-2) is thermally treated together with the organopolysiloxane (A). The organopolysiloxane (A) is preferably represented by the formula: W3−a(R1a)Si(R2)O—(Si(R2)O)n—Si(R1a)W3−a [&agr;] (wherein W represents a hydroxyl group or a hydrolyzable group; each of R1 and R independently represents an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, provided that the hydrocarbon groups R1 as well as the hydrocarbon groups R may be identical with or different from each other; n is an integer of 5 or greater; and a is 0, 1 or 2).

Abstract: A curable composition comprising (A) an organopolysiloxane having functional groups capable of condensation reaction at both molecular terminals thereof and (B-1) a hydrophobic silica and a hydrophilic silica. A curable composition comprising (A) an organopolysiloxane having functional groups capable of condensation reaction at both molecular terminals thereof and (B-2) a hydrophobic silica, wherein the hydrophobic silica (B-2) is thermally treated together with the organopolysiloxane (A).

Abstract: A room temperature rapid-curable silicone composition is provided which includes (A) an organopolysiloxane terminated with hydroxyl groups, having a viscosity of from 25 mPa.s to 1,000,000 mPa.s at 25° C.

Abstract: A hydrosilylation catalyst is provided wherein a platinum catalyst is enclosed in a heat-fusible compound having a melting point of 40-200.degree. C. and containing an aliphatic unsaturated bond, carbonyl, carboxyl or thioether radical in a molecule. The catalyst is blended in organo-polysiloxane to form a silicone composition having both shelf stability and fast-curing capability.

Abstract: More than about 9/10 (by weight as a platinum group metal atom) of the necessary amount of a platinum group metal catalyst enclosed in a compound having a melting or softening point of 40-200.degree. C., less than about 1/10 (by weight as a platinum group metal atom) of the necessary amount of a platinum group metal catalyst, and an addition reaction retarder are blended in an organopolysiloxane composition comprising an organopolysiloxane containing alkenyl or hydroxyl radicals and an organohydrogenpolysiloxane. The composition has improved shelf stability, an increased pot life, good curing capability, and fast curing upon heating.