Patent ID: 8372385
Filing Date: 2013-02-12
Classification: C08G,C08L,C09D

Abstract:
1. A method for preparing an antifouling condensation curing organopolysiloxane composition, said composition comprising 10 to 300 parts by weight of (A) a diorganopolysiloxane selected from the group consisting of methylphenylsilicone oil, polyether-modified silicone oil and long chain alkyl-modified silicone oil, free of a silicon atom-bonded condensation cure reactive group wherein said diorganopolysiloxane has a number average molecular weight of from 250 to 100,000, 0.5 to 100 parts by weight of (B) a hydrophilic and/or hydrophobic silica having a BET specific surface area of at least 10 m 100 parts by weight of (C) a diorganopolysiloxane having at least two silicon atom-bonded hydroxyl and/or hydrolyzable groups in a molecule having the general formula (1): wherein R is independently a substituted or unsubstituted monovalent hydrocarbon group, A is independently an oxygen atom or a divalent hydrocarbon group of 1 to 8 carbon atoms, Y is independently a hydroxyl or hydrolyzable group, m is an integer of 0 to 2, and n is such a number that the diorganopolysiloxane has a viscosity of 20 to 1,000,000 mPa-s at 25° C., and 0.5 to 20 parts by weight of (D) a silane having at least two hydrolyzable groups in a molecule and/or a partial hydrolytic condensate thereof, having the general formula (2): wherein R said method comprising the steps of pre-mixing a part or all of component (A) with a part or all of component (B) to form a premix, then mixing the premix with the remainder of component (A), the remainder of component (B), components (C) and (D) wherein the premixing step includes heating at a temperature from 80° C. to 300° C.