Patent ID: 8329763
Filing Date: 2012-12-11
Classification: C08F,C08L,G02B

Abstract:
1. A hydrogel, comprising: in polymerized form A) 80-100 parts by weight of polyethylene glycol dimethacrylate of the formula (1) B) 20-0 parts by weight of a vinyl compound B copolymerizable with (1), and C) 100-10 000 parts by weight of water, wherein said hydrogel comprises sulfur and a molar polyethylene glycol dimethacrylate/sulfur atoms ratio is <0.5n; wherein said hydrogel comprises an initiator comprising peroxodisulfate; and wherein the polymerization is carried out in the presence of a mercaptan selected from the group consisting of mercaptoethanol, 1-mercapto-2-propanol, and 3-mercapto-1,2-propanediol, and wherein the molar polyethylene glycol dimethacrylate/mercaptan ratio is <0.5n; wherein said hydrogel exhibits a haze of <10%, a light transmittance of >90% and a yellow value of <200.