Patent ID: 8492513
Filing Date: 2013-07-23
Classification: G02B

Abstract:
1. A method for producing a silicone hydrogel having a high water content comprising the following steps: (a) polymerizing a monomer mixture to form the silicone hydrogel, wherein the monomer mixture comprises at least one silicon-containing monomer, a hydrophilic non-ionic monomer, and at least one ionic monomer; and (b) placing the silicone hydrogel in an alkaline solution for at least 20 minutes, wherein the alkaline solution has a pH not less than 7.5 and the ionic monomer is present in an amount not less than 0.7 wt % based on the total dry weight of the silicone hydrogel, the silicon-containing monomer is present in an amount of at least 40 wt % based on the total dry weight of the silicone hydrogel, and the hydrophilic non-ionic monomer is used in an amount not more than 60 wt % based on the total dry weight of the silicone hydrogel.