Curable fluorosilicone composition and method for controlling cure initiation and curing times thereof

摘要

A method for controlling cure initiation time and curing time of a Pt group metal curable fluorosilicone composition, comprising forming a fluorosilicone composition comprising: (A) 100 parts of a F-containing polydiorganosiloxane comprising two or more alkenyl radicals per molecule and repeating units of formula R1RfSiO and optionally R1R2SiO, R1=1-4C alkyl; R2=2-10C alkenyl; Rf=3-12C perfluoroalkylethyl; (B) 10-70 pts.wt. of a treated reinforcing silica filler; (C) an amount of a Pt group metal-containing hydrosilation catalyst to cure the composition; and (D) a crosslinker mixture comprising an alkyl-hydrogen siloxane comprising 3 or more Si-bonded H atoms per molecule with the remaining bonds of the Si atoms being to O or 1-4C alkyl and a dialkyl-hydrogen perfluoroalkyl-ethylsiloxane; controlling the weight ratio of the alkyl-hydrogen siloxane to dialkyl-hydrogen perfluoroalkyl-ethylsiloxane within 0.1:9:1 to control cure initiation time and curing time; and curing the fluorosilicone composition. Also claimed is a curable fluorosilicone composition.