Dow Corning Toray Silicone Company Limited

Toray Silicone Company Limited

Dow Corning Toray Company, Ltd.

Keiji Yoshida

Mitsuo Hamada

Yoshitsugu Morita

Koji Shimizu

Noriyasu Yokoyama

Masayuki Saito

Toyohiko Yamadera

Asao Harashima

Kazuhiko Ando

Atsushi Sakuma

Takayoshi Otomo

Yuji Saito

Atushi Sasaki

A liquid silicone rubber composition comprising an alkenyl group-containing liquid organopolysiloxane, a reinforcing silica filler, an organohydrogenpolysiloxane, a platinum group catalyst, a liquid organopolysiloxane that is free of crosslinking groups and is compatible with the alkenyl group-containing liquid organopolysiloxane, and a liquid organopolysiloxane that is free of crosslinking groups and is incompatible with the alkenyl group-containing liquid organopolysiloxane, wherein the cured material therefrom has a JIS type A durometer hardness of 15 to 26 and a tensile stress at 100% elongation of 0.25 to 0.60 MPa. Also, a through hole-containing sealing member comprising this cured material.

Curable liquid silicone rubber composition for forming a sealing member and sealing member

Method for preparation of an aqueous emulsion from a curable silicone composition consisting of (A) an organopolysiloxane having at least two silicon-bonded hydroxyl groups, (B) an organohydrogensiloxane, and (C) a curing catalyst, said method being characterized by (i) continuously supplying component (A), component (B) and component (C), or a mixture of components (A) and (B) and component (C) through individual inlet ports into a continuous mixer and mixing said components at a temperature not exceeding 10&#xb0; C., (ii) continuously supplying the obtained mixture and (D) an aqueous solution of a surface-active agent to an emulsifier, and emulsifying the components at a temperature not exceeding 20&#xb0; C. An apparatus for the preparation of an aqueous emulsion of a curable silicone composition comprising of a continuous mixer for mixing components (A) through (C), a distribution unit connected to the lower part of the mixer, and an emulsifier. Method for preparation of a suspension of cured silicone particles by allowing such emulsion to stand at room temperature, or heating the aforementioned emulsion.

Apparatus for preparation of aqueous emulsion from curable silicone composition and suspension of cured silicone particles

Method for preparation of aqueous emulsion from curable silicone composition and suspension of cured silicone particles, and apparatus therefor

A silicone-modified water-based coating composition is disclosed wherein a suspension of silicone rubber particles in water is added to a water-based coating composition such that the resulting system is storage-stable and forms a mat film when dried or cured, which film is soft to the touch.

Silicone-modified water-based coating composition

A hydrophobic silica is prepared by mixing and heating a mixture of (a) 100 weight parts wet-method silica and (b) 1 to 100 weight parts organopolysiloxane represented by the following average unit formula R.sup.1.sub.a R.sup.2.sub.b SiO.sub.(4-a-b)/2, wherein R.sup.1 is a monovalent hydrocarbon group, R.sup.2 is the hydrogen atom, a is from 1 to 3 inclusive, and b is from zero to 1 inclusive, with the provisos that a+b is from 1.90 to 2.10 inclusive and b/(a+b) is from zero to 0.45 inclusive. This hydrophobic silica is used to prepare a high-strength silicone rubber particulate by mixing with a curable dioranopolysiloxane and curing the mixture in the form of particulates. A preferred manner of making the particulates is by emulsifying the mixture of hydrophobic silica and curable diorganopolysiloxane in water, then spraying the emulsion into a hot gas to cure the silicone rubber composition and remove the water, giving microparticles of high-strength silicone rubber.

High-strength silicone rubber particulate

The curable resin composition of the present invention consists of a curable resin having uniformly dispersed therein particles of a cured silicone rubber obtained from an organosiloxane composition curable by a platinum-catalyzed hydrosilation reaction, wherein said organosiloxane composition contains reaction products of an ethylenically unsaturated epoxy compound and an ethylenically unsaturated aromatic compound with the organohydrogenpolysiloxane present in said organosiloxane composition. Either or both of the epoxy compound and the aromatic compound can be prereacted with a portion of the silicon-bonded hydrogen atoms of the organohydrogenpolysiloxane.

Curable resin composition containing dispersed particles of a cured

A polish including a film forming wax material and an organopolysiloxane elastomer. The elastomer is in the form of particles mixed with the film forming wax. The particles are spherical and have an average diameter of from about 0.3 um to about 30 um. The polish contains at least one additive selected from the group consisting of organic solvents, silicone oils, and surfactants. The film forming wax material may be one of carnauba wax, montan wax, candelilla wax, ceresin wax, paraffin waxes, and beeswax.

Polish containing silicone elastomer particles

A polish including a film forming wax material and a silicone rubber. The rubber is in the form of particles mixed with the film forming wax, and the silicone rubber particles contain a silicone oil. The particles have an average diameter of from about 0.3 .mu.m to about 30 .mu.m. The polish includes at least one additive selected from the group consisting of organic solvents, a second silicone oil, and surfactants. The film forming wax material is one of carnauba wax, montan wax, candelilla wax, ceresin wax, paraffin waxes, or beeswax. The silicone rubber forming the particles is one of addition reaction curable silicone rubber compositions, condensation reaction curable silicone rubber compositions, organic peroxide curable organopolysiloxane compositions, or high energy curable silicone rubber compositions.

Polish containing a silicone rubber powder

An acrylic rubber composition containing an amino group-containing silicon compound is characterized by excellent roll workability and a rapid vulcanization rate and characteristically does not require secondary vulcanization.

Acrylic rubber composition

Curable fluororubber compositions exhibit excellent processability on roll mills and can be molded without sticking to or staining the mold surfaces when the composition contains from 0.1 to 30 weight parts per 100 weight parts of fluororubber of a finely divided cured silicone material in the form of a rubber, gel or resin. An epoxy-substituted alkoxysilane or a partial hydrolysis product thereof is present as an ingredient of the curable composition when it is desired to cohesively bond the cured fluororubber to a metal or plastic substrate.

Fluororubber composition containing dispersed particles of cured

The cosmetic composition of the present invention exhibits excellent lubricancy since it contains silicone rubber powder containing 0.50-80 wt % of silicone oil. When it is coated on the skin, no foreign sensations or irritations are reported. A smooth and moist texture is obtained.

Silicone cosmetic composition

Cured silicone rubber powder containing large amounts of particulate material formed by dispersing a liquid silicone rubber composition curable by a platinum-catalyzed hydrosilation reaction into water. The presence of a low molecular weight, volatile polydiorganosiloxane makes it possible to incorporate at least 100 parts by weight of particulate material per 100 parts of curable polydiorganosiloxane into the composition. The volatile polydiorganosiloxane is removed from the cured polwder. Finely divided magnetic metals, electrically conductive materials and reinforcing silica powders can be incorporated using the present method.

Method for preparing filled silicone rubber particles

The curable resin composition of the present invention consists of a curable resin and the spherical microparticles of cured silicone rubber obtained by the curing of an addition reacting silicone rubber composition, wherein the silicone rubber composition also contains an epoxy compound having an aliphatically unsaturated group. Furthermore, because the microparticles are prepared from an aqueous emulsion or aqueous dispersion of the silicone rubber composition, it has an extremely small particle size.

Curable resin composition containing a microparticulate silicone rubber

The present invention provides a method for producing silicone rubber moldings composed of a uniform, smooth and hard exterior layer and a relatively soft interior portion. In accordance with this method the surfaces of the mold cavity are coated with an organohydrogenpolysiloxane containing at least two silicon-bonded hydrogen atoms before the curable organosiloxane used to form the interior portion of the molding is injected into the mold cavity and cured.

Method for producing silicone rubber moldings having a hard exterior

Cured silicone rubber in the form of a finely divided powder is prepared by (1) dispersing a heat-curable liquid silicone rubber composition in water maintained at a temperature of from 0.degree. to 25.degree. C., (2) dispersing the resultant dispersion in a liquid heated to a temperature of at least 50.degree. C., and (3) recovering the resultant cured powder. The liquid silicone rubber composition is preferably maintained at a temperature of from -60.degree. to 0.degree. C. before being emulsified and said liquid is preferably water.

Growing community of inventors

Chiba Prefecture, Japan

Keiji Yoshida