Patent ID: 6109748
Filing Date: 2000-08-29
Classification: C09D

Abstract:
A lens wafer suitable for use in preparing a laminated lens said wafer containing on at least one surface thereof a self-supporting removable film which film is a vinyl resin comprising (a) a first copolymer of vinyl chloride and vinyl acetate, wherein said first copolymer comprises from about 75 to about 98 weight percent of vinyl chloride and from about 2 to about 25 weight percent vinyl acetate and further wherein said first copolymer has a number average molecular weight of from about 25,000 to about 28,000: and (b) a second copolymer of vinyl chloride and vinyl acetate, wherein said second copolymer comprises from about 80 to about 90 weight percent of vinyl chloride and from about 10 to about 20 weight percent vinyl acetate and further wherein said second copolymer has a number average molecular weight of from about 40,000 to 50,000; and wherein the weight ratio of the first copolymer to the second copolymer is from about 8:1 to about 19:1; wherein said film is not cross-linked to said wafer surface and further wherein said film encapsulates at least a portion of the contaminants found on the lens surface prior to placement of said film thereon.