Patent ID: 9708087
Date: 2017-07-18
CPC Classifications: B65B,G02B

Claim:
1. A method for producing silicone hydrogel contact lenses with crosslinked hydrophilic coatings thereon, comprising the steps of: (a) obtaining a silicone hydrogel contact lens having amino groups and/or carboxyl groups on and/or near its surface and a water-soluble and thermally-crosslinkable hydrophilic polymeric material, wherein the silicone hydrogel contact lens comprises amino groups or carboxyl groups or both on and/or near the surface of the contact lens, wherein the hydrophilic polymeric material comprises (i) from about 20% to about 95 by weight of first polymer chains derived from an epichlorohydrin-functionalized polyamine or polyamidoamine, (ii) from about 5% to about 80% by weight of hydrophilic moieties or second polymer chains derived from at least one hydrophilicity-enhancing agent having at least one reactive functional group selected from the group consisting of amino group, carboxyl group, thiol group, and combination thereof, and (iii) positively-charged azetidinium groups which are parts of the first polymer chains or pendant or terminal groups covalently attached to the first polymer chains, wherein the hydrophilic moieties or second polymer chains are covalently attached to the first polymer chains through one or more covalent linkages each formed between one azetitdinium group of the epichlorohydrin-functionalized polyamine or polyamidoamine and one amino, carboxyl or thiol group of the hydrophilicity-enhancing agent; and (b) heating the silicone hydrogel contact lens immersed in a packaging solution comprising the hydrophilic polymeric material and at least one buffering agent in an amount sufficient to maintain a pH of from about 6.0 to about 8.5 and has a tonicity of from about 200 to about 450 milliosmol (mOsm) and a viscosity of from about 1 centipoise to about 20 centipoises at 25° C. in a lens package to and at a temperature from about 40° C. to about 140° C. for a period of time sufficient to covalently attach the hydrophilic polymeric material onto the surface of the silicone hydrogel contact lens through second covalent linkages each formed between one azetidinium group of the hydrophilic polymeric material and one of the reactive functional groups on and/or near the surface of the contact lens, thereby forming a crosslinked hydrophilic coating on the silicone hydrogel contact lens, (c) adding a polyazetidinium groups-containing component into the package solution with the silicone contact lens of the step (b), wherein the polyazetidinium groups-containing component comprise at least two groups selected from the group consisting of Formula (II), Formula (III) and mixtures thereof: wherein: R (d) sealing the lens package with the contact lens and the package solution of step (c) (e) reducing the concentration of amino groups and/or carboxyl groups on and/or near the silicone hydrogel contact lens by autoclaving the package with the contact lens and the in-package-coating solution therein of step (d) and inducing reaction between azetidinium groups of the polyazetidinium groups-containing component and residual amino groups and/or carboxyl groups remained on and/or the surface of the silicone hydrogel contact lens immersed in the in-package-coating solution, wherein the reduction of the concentration of carboxyl groups on and/or near the silicone hydrogel contact lens of step (e) is characterized by having an decreased positively charged preservatives uptake in relation to the silicone hydrogel contact lens of step (b) by at least 20%.