Patent ID: 8030369
Filing Date: 2011-10-04
Classification: B29K,C08L,G02B

Abstract:
1. A contact lens which is obtained by crosslinking in a mold an aqueous formulation comprising a crosslinkable polyvinyl alcohol prepolymer, a first non-reactive polyvinyl alcohol having a lower molecular weight M n of from 25000 to 50000, and a second non-reactive polyvinyl alcohol having a higher molecular weight M n of from above 50000 to 100000, wherein the crosslinkable polyvinyl alcohol prepolymer comprises a polyvinylacetate backbone and photocrosslinkable or thermally crosslinkable groups, wherein the first and second non-reactive polyvinyl alcohols are devoid of polymerizable groups, wherein the difference in number-average molecular weight between the first and second non-reactive polyvinyl alcohols is at least 10000, wherein the first and second non-reactive polyvinyl alcohols are present in the aqueous formulation in an amount of from 0.25 to 3% by weight, based on the entire weight of the aqueous formulation, wherein the weight proportion of the lower molecular weight M n non-reactive polyvinyl alcohol and higher molecular weight M n non-reactive polyvinyl alcohol in the aqueous formulation is from 1:1 to 5:1, wherein the contact lens is characterized by having an improved end-of-day wearing comfort relative to contact lenses manufactured according to an identical process without the addition of the amount of the first and second non-reactive polyvinyl alcohols in the aqueous formulation for making the contact lenses.