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AssigneeDow Corning Corporation
InventorsPaul L. Brown, David L. Stickles
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Pressure sensitive adhesives can be protected with a releasable liner having a cured fluoroalkyl silicone coating which contains as little as two percent fluoroalkyl-substituted siloxane units. In a preferred embodiment of this invention silicone pressure sensitive adhesives can be solvent-cast, and even cured, directly onto the release surface of the liner and can be removed from the protective liner with a force of no more than 400 grams per inch. The fluoroalkyl silicone copolymers of this invention are prepared by a process which involves the preparation of a cohydrolyzate of fluoroalkyl-containing and fluoroalkyl-free siloxane units, followed by further polymerization of the cohydrolyzate with other siloxane units.
A coating composition comprising a curable mixture consisting essentially of
A fluorosilicone copolymer having the formula YMe.sub.2 SiO(Me.sub.2 SiO).sub.x {RCH.sub.2 CH.sub.2 Si(Me)O}.sub.y (MeASiO).sub.z SiMe.sub.2 Y wherein Y denotes Me or A, A denotes an omega-alkenyl radical, Me denotes the methyl radical, R denotes a perfluoroalkyl radical having from 4 to 8 carbon atoms and, additionally, 2 to 3 carbon atoms when the fluorosilicone polymer contains less than 90 mol percent fluorinated siloxane units and 1 carbon atoms when the fluorosilicone polymer contains from 7 to 10 mol percent fluorinated siloxane units, the values of x, y and z are each greater than zero and are such that the fluorosilicone polymer contains from 1 to 10 mol percent, but at least 2, alkenyl-containing siloxanes units, at least 5 mol percent fluorinated siloane units and the balance dimethylsiloxane units.
A process for synthesizing a fluorosilicone polymer, said process comprising
Dependencies are inferred from the claim text.