Momentive Performance Materials Japan LLC

Hidefumi Tagai

Hideo Takahashi

Kikuo Mochizuki

Hiroyoshi Iijima

Masanari Shimakawa

Kazuki Shinbo

To provide a polyorganosiloxane composition whose cured product has uniform good flame retardancy and good physical properties with less discoloring, for example, yellowing, and which has excellent temporal stability when stored. A flame-retardant polyorganosiloxane composition contains: (A) straight-chain polyalkylsiloxane having two or more alkenyl groups in one molecule and having a 10,000 to 1,000,000 mPa·s viscosity (25° C.); (B) resinoid polyorganosiloxane containing a Q unit and having 1.5 or more alkenyl groups on average, mass % of the component (B) being 30 to 80 mass % of the total of the components (A), (B); (C) polyorganohydrogensiloxane having three or more Si—H, an amount of the component (C) being such that Si—H/(total of the alkenyl groups in the components (A), (B)) becomes 1.0 to 3.0 moles; and (D) a catalytic amount of a hydrosilylation reaction catalyst, wherein the total content of phosphorus and an alkali metal is 20 mass ppm or less.

Flame-retardant polyorganosiloxane composition, flame-retardant cured product, and optical member

A polyorganosiloxane composition for molding includes: (A) a straight-chain polyorganosiloxane having two or more alkenyl groups and having a viscosity (25&#xb0; C.) of 10,000 to 500,000 mPa&#xb7;s; (B) 30 to 80 mass % of a resinoid polyorganosiloxane including M, D, and Q units, at a molar ratio of a:b:c, on average (0.3&#x2264;a&#x2264;0.6, 0&#x2264;b&#x2264;0.1, 0.4&#x2264;c&#x2264;0.7, and a+b+c=1), and having two or more alkenyl groups; (C) an amount of a polyorganohydrogensiloxane having Si-bonded hydrogen atoms, an average degree of polymerization of 10 or more, a content of the Si-bonded hydrogen atoms of 5.0 mmol/g or more and 11.0 mmol/g or less, and a mass decrease rate up to 140&#xb0; C. by TGA of 2.0 mass % or less so that an amount of the (Si-bonded hydrogen atoms/alkenyl groups) is 1.0 to 3.0 mol; and (D) a hydrosilylation reaction catalyst. A cured product excellent in mold release property is obtained and contamination of a metal mold is prevented.

Polyorganosiloxane composition for molding, optical member, light source lens or cover, and molding method

A heat-curable addition-reactive type silicone rubber composition which gives a molded article having excellent antistatic property, heat resistance, compression set property. The heat-curable addition-reactive type silicone rubber composition includes:

Heat curable addition-reactive type silicone rubber composition

The present invention provides a heat-curable silicone rubber composition capable of giving a stable and high antistatic property for a long time without degrading inherent properties of a silicone rubber, such as thermal stability. The heat-curable silicone rubber composition includes: (A) 100 parts by mass of a mixture of a polyorganosiloxane obtained by polymerization by using an alkali metal hydroxide as a polymerization catalyst and by neutralization, and a curing agent, and (B) 50 to 1000 ppm of an ionic substance containing an anion and a cation, and being a bis(trifluoromethanesulfonyl)imide as the anion.

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Tokyo, Japan

Hidefumi Tagai