Method for producing wettable silicone hydrogel contact lenses

A method for producing coated silicone hydrogel contact lenses, comprising the steps of:

• (1) obtaining a lens mold made of a hydrophobic plastic material, wherein the lens mold comprises a first mold half having a first molding surface and a second mold half having a second molding surface;
• (2) treating the first and second molding surfaces by using a vacuum UV or a corona treatment;
• (3) introducing a polymerizable composition into the lens mold obtained in step (2), wherein the polymerizable composition comprises (a) at least one polysiloxane vinylic crosslinker and/or at least one siloxane-containing vinylic monomer, (b) from about 0.5% to about 4% by weight of at least one carboxyl-containing vinylic monomer relative to the total amount of all polymerizable components, (c) at least one hydrophilic vinylic monomer, (d) optionally at least one non-silicone vinylic crosslinker, and (e) at least one free-radical initiator;
• (4) curing thermally or actinically the polymerizable composition in the lens mold to form a silicone hydrogel lens precursor comprising a bulk silicone hydrogel material that comprises carboxyl groups;
• (5) optionally hydrating the silicone hydrogel lens precursor obtained in step (4) in water or an aqueous solution to obtain a hydrated silicone hydrogel contact lens;
• and
• (6) heating the silicone hydrogel lens precursor obtained in step (4) or the hydrated silicone hydrogel contact lens obtained in step (5) directly in an aqueous solution having a pH from about 6.5 to about 9.5 and including at least one water-soluble, thermally-crosslinkable hydrophilic polymeric material at a temperature from about 60° C. to about 140° C. to form a coated silicone hydrogel contact lens comprising the bulk silicone hydrogel material and a layer of a crosslinked hydrophilic polymeric material that is covalently attached onto the bulk silicone hydrogel material,
• wherein the coated silicone hydrogel contact lens in fully-hydrated state exhibits a water-break-up-time (WBUT) of at least 10 seconds and an oxygen permeability of at least 50 barrers.