| 摘要 |
This flame-retardant polyorganosiloxane composition comprises: (A) a straight-chain polyorganosiloxane including two or more alkenyl groups in a single molecule, and having a viscosity (25°C) of from 10,000 to 1,000,000 mPa·s; (B) from 30 to 80 mass% of a resin-form polyorganosiloxane including Q units and including 1.5 or more alkenyl groups on average, wherein the molar ratio of alkoxy groups to substituted or non-substituted alkyl groups is 0.030 or less; (C) a polyorganohydrogen siloxane including Si-H, having an average degree of polymerization of 10 or greater, and having an Si-H content of 5.0 mmol/g or greater, the amount of said polyorganohydrogen siloxane being such that the ratio of Si-H to the total amount of alkenyl groups in components (A) and (B) is from 1.0 to 3.0 mol; and (D) a catalytic amount of a hydrosilylation reaction catalyst. Thus, it is possible to provide a flame-retardant polyorganosiloxane composition in which the blending amount of platinum-based metal compounds is suppressed, and with which it is possible to obtain, at low cost, a cured product having excellent flame retardancy. |
