Patent ID: 8128990
Filing Date: 2012-03-06
Classification: C09D,G02B

Abstract:
1. A method of forming an abrasion resistant coating on an ophthalmic lens, the method comprising: coating the ophthalmic lens with a composition comprising (a) a rigid multifunctional monomer, (b) a flexible difunctional monomer, and (c) colloidal silica, wherein the rigid multifunctional monomer (a) is a monomer having two or more functional groups bonded to a rigid backbone which yields a polymer having a glass transition temperature of greater than about 130° C. when homopolymerised, and wherein the flexible difunctional monomer (b) is a difunctional polyoxyalkylene monomer having an average of four or more oxyalkylene units and at least two functional groups joined by a relatively flexible backbone that yields a polymer having a glass transition temperature of less than about 40° C. when homopolymerised; and polymerising the coating comprising copolymerizing the rigid multifunctional monomer (a) with the flexible difunctional monomer (b) to form an abrasion resistant coating on the ophthalmic lens; and wherein the weight ratio of rigid multifunctional monomer to flexible difunctional monomer in the composition is between about 1:19 and about 1:2.125.