Patent ID: 7354959

Claim:
An ink for making colored contact lenses, comprising: water; at least one colorant; and a water-soluble and actinically-curable binder polymer which is a vinyl group-terminated polyurethane polymer, a vinyl group-terminated polyurea binder polymer, or a mixture thereof, wherein the vinyl group-terminated polyurethane polymer is a reaction product of: an isocyanate-capped polyurethane with an ethylenically unsaturated amine (primary or secondary amine) or an ethylenically unsaturated monohydroxy compound, or a hydroxy-capped polyurethane with an isocyanate-containing acrylate or methacrylate, wherein the isocyanate-capped or hydroxy-capped polyurethane is a copolymerization product of a reactive mixture comprising at least one polyalkyleneglycol and at least one diisocyanate, wherein the vinyl group-terminated polyurea polymer is obtained by reacting an acryloylchloride or an isocyanate group-containing acrylate or methacrylate with an amine-capped polyurea, or by reacting an ethylenically unsaturated amine (primary or secondary) or an ethylenically unsaturated monohydroxy organic compound with an isocyanate-capped polyurea, wherein the amine- or isocyanate-capped polyurea is a copolymerization product of a reactive mixture comprising at least one poly(oxyalkylene)diamine and at least one diisocyanate, and wherein the ink is characterized by having a viscosity greater than 50 centipoise (cps), a prolonged stability of at least 8 hours, and a good adhesion to a HEMA-based hydrogel contact lens.