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: A material in the form of polyamide fibers, polyester fibers, woven and non--woven fabric thereof, thermoplastic elastomer, and polyurethane sheet is coated with a silicone coating composition to a thickness of 5 to 20 .mu.m, obtaining a silicone coated base material. The silicone coating composition contains (A) an organopolysiloxane having at least two alkenyl groups, (B) an organohydrogenpolysiloxane having at least two hydrogen atoms, (C) an organic silicon compound having at least one hydrogen atom and at least one epoxy and/or trialkoxy-silyl group, (D) a carbon, NiO.sub.2, FeO, FeO.sub.2, Fe.sub.2 O.sub.3, Fe.sub.3 O.sub.4, CoO.sub.2, CeO.sub.2 or TiO.sub.2 powder having a mean particle size of up to 20 .mu.m, and (E) a platinum catalyst. The silicone coated base material is flame resistant and fully acceptable in practical use even though the silicone coating is as thin as 5 to 20 .mu.m, namely less than about one-half of the conventional coating thickness.

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: A process for preparing a liquid silicone rubber base composition of the type which comprises (A) an organopolysiloxane of the following average compositional formula (1)R.sub.a SiO.sub.(4-a)/2 (1)wherein each R independently represents an unsubstituted or substituted monovalent hydrocarbon group and a is a value of from 1.95 to 2.05, and (B) a finely divided silica filler is described. The process comprises the steps of mixing a first portion of the ingredient (A) and the ingredient (B) at a temperature not higher than 80.degree. C., further mixing a second portion of the ingredient (A) with the mixture obtained in the first step at a temperature not higher than 80.degree. C. and subjecting the resultant mixture to thermal treatment at a temperature of 130.degree. to 200.degree. C. By this, the base composition has good fluidity and is able to yield a cured product having good tear strength under stress.

Abstract: An organopolysiloxane composition contains (A) a both end hydroxyl-blocked diorganopoly-siloxane, (B) a hydroxyl-free diorganopoly-siloxane having a degree of polymerization equal to or greater than that of (A), (C) an organo-hydrogenpolysiloxane having at least three hydrogen atoms in a molecule, (D) an organosilane containing at least two alkoxy groups and an amino group attached to a silicon atom through an alkylene group in a molecule and/or a partial hydrolyzate thereof, (E) a fatty acid metal salt, (F) polycarbonate powder having a mean particle size of up to 50 .mu.m, and optionally (G) an organo-silane containing at least two alkoxy groups and a mercapto group attached to a silicon atom through an alkylene group in a molecule and/or a partial hydrolyzate thereof. It is applied to a rubber substrate to form a wear resistance coating thereon.

Abstract: A silicone rubber composition comprising (1) a diorganopolysiloxane blocked with a hydroxysilyl group at either end, (2) a silane or siloxane having at least three hydrolyzable silyl groups in a molecule, and (3) a divalent organic tin compound in a form substantially isolated from air quickly cures into a silicone rubber elastomer simply by heating at 40.degree. to 200.degree. C.

Abstract: A process for preparing a liquid silicone composition of the type which comprises (A) a diorganopolysiloxane having a viscosity of 1000 to 100,000 centipoises and having at least two reactive groups, (B) a filler mainly composed of SiO.sub.2 having a specific surface area of not smaller than 50 m.sup.2 /g, (C) a diorganopolysiloxane having a viscosity of from 10 to 1000 centipoises and substantially free of any terminal silanol group, (D) hexamethyldisilazane and/or (E) water is described. In the process, 10 to 100 wt % of the (A) and (C) components and 100% of the (B), (D) and, if present, (E) components are mixed under heating conditions of 100.degree. to 250.degree. C. for a time sufficient to obtain a uniform dispersion. If present, the balances of the (A) and (C) components are subsequently mixed with the dispersion.

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: In a polypropylene resin/silicone rubber integrally molded article, a polypropylene resin having an aliphatic unsaturated bond is integrally joined to an addition type silicone rubber at high bond strength. It is prepared by injection molding a modified polypropylene resin into a preform, injection molding a silicone rubber composition over the preform, and curing the composition at a temperature below the softening point of the polypropylene resin. Stronger bond is established when the silicone rubber contains a tackifier in the form of a compound containing in a molecule at least one hydrogen atom directly attached to a silicon atom and an alkoxysilyl, glycidyl or acid anhydride group or a --(CH.sub.2).sub.n -- linkage.

Abstract: A novel organic silicon compound having at least one .tbd.SiH group in a molecule and a fluorinated organic group at either end is a useful crosslinking agent for various resins, especially fluorinated resins. An organopolysiloxane composition comprising (A) an organopolysiloxane having in a molecule at least two alkenyl groups and at least one fluorinated substituent, (B) an organohydrogenpolysiloxane having at least two .tbd.SiH groups in a molecule and a fluorinated organic group at either end, and (C) a platinum catalyst is readily curable to products having solvent and moisture resistance.

Abstract: An adhesive silicone rubber composition of addition reaction curing type comprising (a) an organopolysiloxane containing an alkenyl group; (b) an organohydrogenpolysiloxane having at least one hydrogen atom directly attached to a silicon atom in a molecule; (c) an addition reaction catalyst; and (d) an adhesive agent selected from compounds of the following formulae (I), (II) and (III):A-(D-B).sub.x -D-A (I)C-(B-D).sub.

Abstract: An integrated thermoplastic resin/silicone rubber article is prepared by modifying a thermoplastic resin with a silicon-containing compound in monomer or polymer form, molding the thermoplastic resin into a shape, contacting an uncured silicone rubber with the molded thermoplastic resin, and curing the silicone rubber at a temperature below the softening point of the thermoplastic resin. The article in which the thermoplastic resin is firmly united with the silicone rubber is useful in electric, electronic and automotive applications while taking advantage of the inherent reliability in heat resistance, weather resistance and electrical properties of the silicone rubber.

Abstract: In a polycarbonate resin/silicone rubber integrally molded article, a polycarbonate resin having an aliphatic unsaturated group, typically an isopropenyl group is integrally joined to an addition type silicone rubber containing a tackifier component at high bond strength. It is prepared by injection molding a modified polycarbonate resin into a preform, injection molding a silicone rubber composition over the preform, and curing the composition at a temperature below the softening point of the polycarbonate resin.

Abstract: A impression composition comprising:(A) a polyether polymer having at least two alkenyl groups in its molecule,(B) a polyorganohydrogensiloxane having at least three silicon-bonded hydrogen atoms in its molecule,(C) a platinum catalyst,(D) an inorganic filler, and(E) an antioxidant.This composition of has hydrophilic nature and a small cure shrinkage; hence it enables precise impression in a wet environment like in a mouth.

Abstract: To a silicone rubber adhesive composition comprising (A) a diorganopolysiloxane containing at least two alkenyl groups in a molecule, (B) a diorganohydrogenpolysiloxane having at least two hydrogen atoms directly attached to silicon atoms in a molecule and a viscosity of about 5 to about 5,000 cs at 25.degree.C., (C) an adhesion modifier compound containing in its molecule a group represented by (RO).sub.3 Si-- or H(RO).sub.2 Si-- wherein R is selected from the group consisting of methyl, ethyl, trifluoroethyl, hexafluoropropyl, and methoxyethyl groups, and (D) a platinum catalyst is added (E) an organic tin compound. The combined use of components (C) and (E) provides he synergistic effect that the resulting adhesive composition can firmly adhere to even polycarbonate and polyphenylene sulfide resins which are known as difficultly bondable resins.

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 adhesion composition comprising:(A) a high molecular weight fluorosilicone polymer containing the unit having the formula (1):RfCH.sub.2 CH.sub.2 (CH.sub.3)SiO-- (1)wherein Rf is a perfluoroalkyl group containing 1 to 8 carbon atoms, in an amount of 30 mol % or more in the molecule, and blocked with the vinyl group at the both ends,(B) a low molecular fluorosilicone polymer containing the unit having the formula (1) in an amount of 30 mol % or more in the molecule, and containing an average of 3 or more units having the following formula (2):CH.sub.2 .dbd.CH(CH.sub.3)SiO-- (2),(C) an organohydrogenpolysiloxane,(D) an organosilane or organopolysiloxane having at least one hydrogen atom or alkenyl group bonded to a silicon atom and having at least one of the oxirane group, dialkoxysilyl groups or trialkoxysilyl groups, and(E) a platinum catalyst. The cured product of the composition has good resistance to gasoline, and therefore useful for automobile parts.

Abstract: A silicone gel composition, comprising as essential components(A) an organopolysiloxane comprising substantially 90 to 97 mol % of R(CH.sub.3)SiO units, 0.1 to 2.5 mol % of RSiO.sub.1.5 units, and 0.1 to 4.0 mol % of CH.sub.3 R(CH.sub.2 .dbd.CH)Si.sub.0.5 units, wherein R represents a group selected from the group consisting of a methyl group, a phenyl group, and a CF.sub.3 CH.sub.2 CH.sub.2 -- group, provided that the total of the phenyl groups and the CF.sub.3 CH.sub.2 CH.sub.2 -- groups out of the R groups amounts to 0.5 to 10 mol % in all the R groups,(B) a hydrogenpolysiloxane containing at least one silicon-bonded hydrogen atom per molecule in such an amount that the number of the silicon-bonded hydrogen atoms is 0.5 to 1.5 per vinyl group bonded to silicon atoms in the component (A), and(C) a platinum catalyst. From this composition, a silicone gel excellent damping properties, rapid curability, and low-temperature properties can be obtained.

Abstract: A primer composition has blended therein an organic silicon compound having in a molecule at least one group of the formula: ##STR1## wherein R.sup.1 is a monovalent hydrocarbon group or a group represented by QSi( R.sup.4 O).sub.a (R.sup.5).sub.3-a, Q is a divalent organic group, R.sup.4 and R.sup.5 each are a monovalent hydrocarbon group, a is an integer of 0 to 3, R.sup.2 and R.sup.3 each are a hydrogen atom or a monovalent hydrocarbon group, and n is 0, 1 or 2. The primer composition is a useful adhesive since it is effective for joining silicone elastomers and similar adherends to supports such as paint coated metals and resins.

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.