Abstract: A hydrolyzable group-containing organohydrogenpolysiloxane is prepared by (A) reacting (a) an organosiloxane with (b) an organosilane or organosiloxane containing a hydrolyzable group, at least one of components (a) and (b) containing hydrosilyl, in the presence of a superstrong acid catalyst, (B) adding an inorganic basic neutralizing agent and/or an adsorbent to the resulting reaction solution, and (C) removing the neutralized and/or adsorbed form of the superstrong acid catalyst. The process proceeds in an essentially non-aqueous system, and the organohydrogenpolysiloxane free of residual acidic catalyst is obtainable at low cost.

Abstract: A hydrolyzable group-containing organohydrogenpolysiloxane is prepared by (A) reacting (a) an organosiloxane with (b) an organosilane or organosiloxane containing a hydrolyzable group, at least one of components (a) and (b) containing hydrosilyl, in the presence of a superstrong acid catalyst, (B) adding an inorganic basic neutralizing agent and/or an adsorbent to the resulting reaction solution, and (C) removing the neutralized and/or adsorbed form of the superstrong acid catalyst. The process proceeds in an essentially non-aqueous system, and the organohydrogenpolysiloxane free of residual acidic catalyst is obtainable at low cost.

Abstract: A hydrosilyl radical-bearing organosilicon compound is applied to a substrate which has been coated with an aliphatic unsaturated hydrocarbon radical-bearing material, whereupon reaction takes place between the coating of aliphatic unsaturated hydrocarbon radical-bearing material and the hydrosilyl radical-bearing organosilicon compound. A fully durable functional coating is formed on the substrate surface. The method can modify surfaces of plastics, metals, ceramics, pottery and glass substrates for imparting functions such as water repellent, hydrophilic, anti-staining or electroconductive properties thereto.

Abstract: An optical communication device substrate made of ceramic or glass-ceramic having a negative thermal expansion coefficient in the range of −10 to −120×10−7/° C. in a temperature range of −40 to 100° C., treated with a solution containing at least one organic silicon compound selected from the group consisting of siloxane compounds and silazane compounds.

Abstract: A surface treating agent is comprised of the reaction product obtained by reacting with ammonia a mixture of (A) an organosilicon compound having a fluorinated organic group and (B) an organosilicon compound having a hydrolyzable group. Substrates treated therewith exhibit high water and oil repellency and allow sticking contaminants to be effectively wiped off.

Abstract: An optical communication device substrate made of ceramic or glass-ceramic having a negative thermal expansion coefficient in the range of −10 to −120×10−7/° C. in a temperature range of −40 to 100° C., treated with a solution containing at least one organic silicon compound selected from the group consisting of siloxane compounds and silazane compounds.

Abstract: A surface treating agent is comprised of the reaction product obtained by reacting with ammonia a mixture of (A) an organosilicon compound having a fluorinated organic group and (B) an organosilicon compound having a hydrolyzable group. Substrates treated therewith exhibit high water and oil repellency and allow sticking contaminants to be effectively wiped off.

Abstract: A composition comprising a trifunctional polysilazane and a polysiloxane having at least one hydrolyzable group and an optional fluoroalkyl group is effective for treating substrates to render their surface water repellent, oil repellent, and anti-fouling.

Abstract: A hydrolyzate resulting from co-hydrolysis of a perfluoroalkyl group-containing organic silicon compound and a hydrolyzable group-containing methylpolysiloxane compound in a hydrophilic solvent is blended with an organopolysiloxane and a strong acid to constitute a water repellent composition which is effective for imparting water repellency and facilitating falling of water droplets and thus imparting excellent water repellency and stain-proofness to a surface of an article treated therewith.

Abstract: A hydrolyzate resulting from co-hydrolysis of a perfluoroalkyl group-containing organic silicon compound and a hydrolyzable group-containing methylpolysiloxane compound in a hydrophilic solvent and water constitutes a water repellent agent which is effective for imparting water repellency and facilitating falling of water droplets and thus imparting excellent water repellency and stain-proofness to a surface of an article treated therewith.

Abstract: Organopolysiloxane compounds represented by the following general formula (I), which can fully achieve their effects as functional group when introduced as cross-linking groups into moisture cross-linkable polymers: ##STR1## (wherein R' represents methyl group or hydrogen atom; R.sup.2 represents methyl group or ethyl group; m represents an integer from 1 to 3; n represents an integer from 3 to 50; k represents 1 or 2 and l represents 2 or 3).

Abstract: The rubber composition without formulating a carbon black filler has a remarkably low Mooney viscosity and still is capable of giving a rubber vulcanizate having excellent mechanical properties. The rubber composition comprises, in addition to natural rubber or a diene-based synthetic rubber and a non-carbon inorganic filler, a specific poly(dialkoxysiloxane) terminated at each molecular chain end with a polysulfide linkage-containing group of the formula (RO).sub.3 Si--R.sup.1 --S.sub.x -- R.sup.1 --bonded to the terminal silicon atom, in which R is an alkyl group, e.g. methyl and ethyl, R.sup.1 is a divalent hydrocarbon group, e.g. --CH.sub.2 CH.sub.2 CH.sub.2 13 , and x is a positive integer of 2 to 6 or, typically, 4.

Abstract: The novel organosilicon compound of the invention has two polysulfide linkages in a molecule and is represented by the general formula(R.sup.1 O).sub.3 Si--R.sup.2 --S.sub.x --R.sup.3 --S.sub.x --R.sup.2 --Si(OR.sup.1).sub.3,in which R.sup.1 is an alkyl group having from 1 to 4 carbon atoms, R.sup.2 is a divalent hydrocarbon group having from 1 to 10 carbon atoms, R.sup.3 is a divalent hydrocarbon group having from 2 to 10 carbon atoms or a divalent hydrocarbon group additionally containing one or more of the linking units of the formula --O-- or --CO--O-- in the structure and X is a positive integer of from 2 to 6. The compound is useful as an additive in a rubber composition based on natural rubber or a diene-based synthetic rubber and a non-carbon inorganic filler to greatly improve the mechanical properties of the vulcanizate without increasing the Mooney viscosity of the unvulcanized rubber composition.