CONDENSATION REACTION CURABLE SILICONE ORGANIC BLOCK COPOLYMER COMPOSITION CONTAINING A PHOSPHONATE CATALYST AND METHODS FOR THE PREPARATION AND USE OF THE COMPOSITION

摘要

A condensation reaction curable composition comprises a new catalyst, Dow Corning® 4-6085, and a polyorganosiloxane polyoxyalkylene block copolymer having one or more polyorganosiloxane blocks and one or more polyoxyalkylene blocks linked to each other via divalent radicals which comprises at least two silicon-bonded alkoxy groups, preferably of the form PS-(A-PO)m-(A-PS)n, wherein PO is a polyoxyalkylene block, PS represents a polyorganosiloxane block, A is a divalent radical, subscripts m and n have independently a value of at least 1, comprising at least one alkoxy-substituted siloxane unit of the formula (R')q(OR)-SiO3-q/2, wherein R represents an alkyl group having 1 to 4 carbon atoms and each R' represents an alkyl group having 1 to 6 carbon atoms, a phenyl group, or an alkoxy group of the formula -OR and subscript q has a value of 0, 1 or 2, provided at least two silicon-bonded groups OR are present in the block copolymer.