Patent ID: 9623614
Date: 2017-04-18
CPC Classifications: B29D,C08L,G02B

Claim:
1. A method for producing a contact lens, comprising: the steps of: introducing a fluid composition into a mold for making a contact lens, wherein the fluid composition comprises a lens-forming material and a Butylated Polyvinylpyrrolidone, wherein the lens-forming material is a water-soluble crosslinkable poly(vinyl alcohol) prepolymer which is crosslinkable and/or polymerizable by actinic radiation or by heating; crosslinking/polymerizing the lens-forming material in the mold to form a lens having a polymer matrix; and separating the mold, wherein the Butylated Polyvinylpyrrolidone present in an amount sufficient to reduce an averaged mold separation force by at least about 20% in comparison with that without the Butylated Polyvinylpyrrolidone; wherein the Butylated Polyvinylpyrrolidone having a molecular weight of about 12,000 Da to 22,000 Da.