Room-temperature-curable organopolysiloxane composition and production method for same

A method for preparing a room temperature-curable organopolysiloxane composition comprising the steps of:

• mixing (i) a diorganopolysiloxane having the general formula (1):
• wherein R which is the same or different is an unsubstituted or substituted monovalent hydrocarbon group and a is an integer of at least 10, (ii) a hydroxy-containing hydrocarbon compound having the general formula (2):
• R1—OH (2)
• wherein R1 which is the same or different is an unsubstituted or substituted monovalent hydrocarbon group of 3 to 20 carbon atoms, in an amount of 0.01 to 0.5 mole per mole of silicon-bonded hydroxy groups in the diorganopolysiloxane as component (i), and (iii) chloroplatinic acid hexahydrate in an amount of 0.01 to 1% by weight based on the total weight of components (i), (ii) and (iii), at 0° C. to 50° C. for at least 5 minutes, to form a reaction product (A), and
• uniformly mixing 100 parts by weight of the reaction product (A) with
• (B) 3 to 300 parts by weight of an inorganic filler,
• (C) 1 to 20 parts by weight of an organosilane having at least 3 hydrolyzable groups per molecule and/or a partial hydrolytic condensate thereof,
• (D) 0.01 to 5 parts by weight of a condensation curing catalyst, and
• (E) 0.1 to 5 parts by weight of an amine base silane coupling agent having an alkoxysilyl group as a hydrolyzable group exclusive of components (C) and (D).