Patent ID: 8283429
Filing Date: 2012-10-09
Classification: C08F,C08L

Abstract:
1. A soft contact lens, comprising a silicone hydrogel material that is obtained by curing a lens-forming material in a mold, wherein the lens-forming material comprises an actinically crosslinkable or polymerizable prepolymer, wherein the prepolymer comprises (1) siloxane units derived from one or more siloxane-containing compounds each with two terminal first or second functional groups; (2) hydrophilic units derived from one or more linear hydrophilic monomers or polymers, wherein each hydrophilic monomer or polymer has two terminal first or second functional groups; and (3) from about 2% to about 30% by weight of dangling hydrophilic polymer chains that are derived from one or more hydrophilic polymers each having one sole first or second functional group and are free of actinically-crosslinkable groups, wherein the pre-formed hydrophilic polymer has a molecular weight of from 2000 to about 6000 Daltons and sufficient low to be efficiently and covalently incorporated in the prepolymer but sufficient high to provide the soft contact lens with a water contact angle of about 90 degrees or less without post-curing surface treatment, wherein the prepolymer is obtained from an intermediary copolymer with pendant or terminal functional groups and dangling hydrophilic polymer chains by covalently attaching actinically crosslinkable groups to the intermediary copolymer through the pendant or terminal functional groups, wherein the pendant or terminal functional groups are selected from the group consisting of hydroxy groups, amino groups (—NH wherein the intermediary copolymer is obtained by copolymerization of a mixture comprising (a) the one or more linear siloxane-containing compounds each with two terminal first or second functional groups, (b) the one or more linear hydrophilic monomers or polymers each with two terminal first or second functional groups, (c) the one or more hydrophilic polymers each with only one first or second functional group, and (d) one or more branching agents which independently of each other are an organic compound with three or more first or second functional groups, wherein the first and second functional groups are different from each other and selected from the group consisting of amine group, hydroxyl, carboxy, isocyanate, epoxy, and acid halide group, wherein the first and second functional groups are different from each other but coreactive with each other in the presence or absence of a coupling agent to form a covalent linkage selected from the group consisting of urethane, urea, ether, and amide, wherein the ratio of molar equivalents of the first functional groups to the second functional groups or of the second functional groups to the first functional groups in the mixture is from about 1.1 to about 20.