Dow Corning Toray Silicone Company Limited

Dow Corning Toray Company, Ltd.

Ken Tanaka

Yoshitsugu Morita

Kazuo Kobayashi

Toshio Saruyama

Junji Nakanishi

A silicone rubber powder obtained by curing a condensation-curable silicone rubber composition in a dispersed state in water, having an epoxy equivalent measured by a titration method equal to or lower than 3,000 and an average particle size in the range of 0.1 to 100 &#x3bc;m; and a method of manufacturing a silicone rubber powder comprising the steps of dispersing in water a silicone rubber composition comprising at least components (A) through (C) listed below; adding component (D); and curing the mixture: (A) a diorganopolysiloxane capped at both molecular terminals with silanol groups and having in one molecule 30 or less silicon atoms; (B) an organopolysiloxane having in one molecule at least two silicon-bonded hydrogen atoms; (C) an epoxy-containing alkoxysilane; and (D) a condensation-reaction catalyst. The silicone rubber powder has low epoxy equivalent and possesses excellent dispersibility in organic resins, and the method is efficient in manufacturing of the aforementioned powder.

Silicone rubber powder and method of manufacturing thereof

Water base coating material compositions form coating films of superior flat finish properties. They contain silicone particles with at least two kinds of different average particle size. According to the method of making the composition, a water base coating material composition can be formed by adding an aqueous suspension of silicone particles to a water base coating material composition where the aqueous suspension contains at least two kinds of silicone particles with different average particle size.

Water base coating material composition and production process

A suspension containing crosslinked silicone particles with a lower mean particle diameter and a better dispersion in certain organic resins is prepared by emulsifying a condensation crosslinkable silicone composition containing (A) an organopolysiloxane having at least two silanol groups per molecule and (B) a crosslinker, but no (C) condensation catalyst, in water using a surfactant. A tin (II) salt of an organic acid with no more than ten carbon atoms is then emulsified in water with a surfactant, and added as the component (C) to the emulsion of condensation crosslinkable silicone composition. This crosslinks the emulsion of condensation crosslinkable silicone composition.

Method for producing suspension of crosslinked silicone particles

An efficient method is provided for producing water based coating compositions that are capable of forming highly scratch and abrasion resistant matte coatings in which crosslinked silicone particles are well dispersed. The method involves addition to a water based coating composition of a waterborne suspension of crosslinked silicone particles having an average diameter of 0.1-200 &mgr;m. The method is characterized in that the suspension is a waterborne crosslinked silicone particle suspension provided by effecting crosslinking of a condensation reaction crosslinkable silicone composition comprising (A) an organopolysiloxane containing at least two silanol groups in each molecule, (B) a crosslinker, and (C) a condensation reaction catalyst. The crosslinking is effected in the emulsified composition in an aqueous solution of an anionic surfactant.

Method for producing water based coating compositions

There is disclosed a curable resin composition that has an excellent fluidity prior to curing and that cures to form a molding resin that is flexible, highly moisture resistant, and strongly resistant to heat shock, said composition comprising (A) 100 weight parts of a curable resin; and (B) 0.1 to 500 weight parts of an epoxy group-containing silicone resin that has the general formula

Epoxy group-containing silicone resin and compositions based thereon

There is disclosed a curable resin composition that has an excellent fluidity prior to curing and that cures to form a molding resin that is flexible, highly moisture resistant, and strongly resistant to heat shock, said composition comprising

An organopolysiloxane suitable for modifying curable organic and silicone compositions is disclosed, said organopolysiloxane having the general formula ##STR1## wherein each R.sup.1 is a monovalent group independently selected from the group consisting of alkyl radicals having 1 to 5 carbon atoms and phenyl radical; R.sup.2 is a monovalent group independently selected from the group consisting of hydrogen, alkyl radicals having 1 to 5 carbon atoms and phenyl radical; R.sup.3 is selected from the group consisting of alkoxysilylalkyl groups and alkyl groups having at least 6 carbon atoms; a is zero or a positive number; b is a positive number; c is a positive number; a/c has a value of zero to &lt;4; b/c has a value of 0.05 to 4; and (a+b)/c has a value of 0.2 to 4, with the proviso that said organopolysiloxane has in its molecule at least one said alkoxysilylalkyl group and at least one said alkyl group having at least 6 carbons.

Growing community of inventors

Chiba Prefecture, Japan

Ken Tanaka