Heat stable acrylamide polysiloxane composition

Claim 2

A composition comprising a polydiorganosiloxane having on the average more than about 0.4 acrylamide functional groups per molecule and being crosslinkable by exposure to ultraviolet radiation in the presence of a photosensitization system, an effective amount of a heat stability additive selected from the group consisting of nickel naphthenate, stannous naphthenate, cerium naphthenate, manganese naphthenate, aluminum octoate, silver octoate, nickel octoate, copper undecylenate, cobalt octoate, mono(methacrylate) tripropoxyzirconate, mono(ethylacetoacetonate) aluminum di(sec-butoxide), di(ethylacetoacetonate)aluminum secbutoxide, zinc acetylacetonate, molybdenum acetylacetonate and dibutyltin dilaurate and an effective amount of a photosensitization system.

Claim 3

The composition according to claim 2 in which the polydiorganosiloxane is a blend of (A) 4 to 90 mole percent of an acrylamide functional endblocked polydiorganosiloxane of the general formula YR'₂SiO(R₂SiO) n SiR'₂Y, (B) 9 to 50 mole percent of a monoacrylamide functional endblocked polydiorganosiloxane of the general formula R'₃SiO(R₂SiO) n SiR'₂Y, and (C) 0 to 65 mole percent of a non-functional polydiorgano-siloxane of the formula R'₃SiO(R₂SiO) n SiR'₃ where, in the above formulae, R is a monovalent radical selected from the group consisting of alkyl, aryl and fluorinated alkyl; each R' is independently selected from the group consisting of R and hydroxyl, Y is an acrylamide functional radical bonded to silicon atom through silicon-carbon bond where the acrylamide function has the formula or the formula in which R'' is a hydrogen atom or methyl, R² is hydrogen atom or an alkyl of 1 to 4 carbon atoms, R³ is a divalent hydrocarbon radical having from 1 to 10 carbon atoms per radical, R* is a divalent hydrocarbon radical or a divalent hydrocarbon radical containing ether linkages and n has a value of from 30 to 3,000, the mole percentages being based on the total blend as 100 mole percent and where the polydiorganosiloxanes of the blend are present in amounts to provide 20 to 95 percent of the endblocking as acrylamide functionality and 5 to 80 percent of the endblocking as non-functional.