Patent ID: 8163206
Filing Date: 2012-04-24
Classification: C08F,G02B

Abstract:
1. A method for producing silicone hydrogel contact lenses, comprising the steps of: providing a mold for making a soft contact lens, wherein the mold has a first mold half with a first molding surface defining the anterior surface of a contact lens and a second mold half with a second molding surface defining the posterior surface of the contact lens, wherein said first and second mold halves are configured to receive each other such that a cavity is formed between said first and second molding surfaces; introduce a monomer mixture of lens-forming materials into the cavity, wherein the monomer mixture comprises (1) from about 10% to about 50% by weight of a hydrophilic amide-type vinylic monomer, (2) from about 10% to about 40% by weight of a siloxane-containing (meth)acrylamide monomer, (3) from about 10% to about 40% by weight of a polysiloxane-containing vinylic macromer, (4) from about 0.1% to 1.3% by weight of a photoinitiator, and (5) from 0 to 5% by weight of a polymerizable UV-absorbing agent or a polymerizable latent UV-absorbing agent, wherein if one or more methacrylate monomers are present in the monomer mixture, the total amount of the methacrylate monomers is less than about 5% by weight and the monomer mixture is characterized by having a curing time of less than 100 seconds by a UV light having an UV-intensity of about 4.1 mW/cm2; and irradiating, under a spatial limitation of actinic radiation, the monomer mixture in the mold for a time period of about 80 seconds or less, so as to crosslink the monomer mixture to form the silicone hydrogel contact lens, wherein the produced contact lens comprises an anterior surface defined by the first molding surface, an opposite posterior surface defined by the second molding surface, and a lens edge defined by the spatial limitation of actinic radiation.