Patent attributes
The invention provides a chain-extended polydiorganosiloxane vinylic crosslinker which comprises (1) a polymer chain comprising at least two polydiorganosiloxane segments and one hydrophilized linker between each pair of polydiorganosiloxane segements, wherein each polydiorganosiloxane comprises at least 5 dimethylsiloxane units in a consecutive sequence, wherein the hydrophilized linker is a divalent radical having at least two (meth)acrylamide moieties; (2) two terminal (meth)acryloyl groups, wherein the chain-extended polydiorganosiloxane vinylic crosslinker has an average molecular weight of at least about 1500 Daltons. The present invention is also related to a silicone hydrogel contact lens, which comprises repeating units derived from a chain-extended polydiorganosiloxane vinylic crosslinker of the invention. In addition, the invention provides a method for making silicone hydrogel contact lenses using a lens-forming formulation comprising a chain-extended polydiorganosiloxane vinylic crosslinker of the invention.
