Polymer for contact lenses

摘要

The present invention relates to a polyurethane polymer composition prepared by reacting a mixture comprising: a} at least one polyethylene glycol, and either b) at least one poly-isocyanate, having a functionality greater than 2 or c) at least one di-isocyanate and at least one polyol or at least one macropolyol having a functionality greater than 2, wherein the polyol or macropolyol is present at an amount of 0.1 to 9 wt % of the mixture. The invention also relates to a process for preparing a polyurethane xerogel in the form of a molded article, said process comprising the steps of: i.) preparing said mixture; ii.) dispensing the reaction mixture formed in step i) into a mold; iii.) allowing the reaction mixture to react and cure; iv.) removing the molded article from the mold; and v.) hydrating the molded article.

主权项

1. A contact lens formed from a polyurethane polymer composition prepared by reacting a mixture comprising:
(a) 10 to 70 wt % of at least one polyethylene glycol having a number average molecular weight of 1000 or less and 10 to 70 wt % of at least one polyethylene glycol having a number average molecular weight of 3000 to 8000; (b) 9 to 50 wt % of at least one di-isocyanate; and (c) at least one polyol or at least one macropolyol having a functionality greater than 2, wherein the polyol or macropolyol is present at an amount of 0.1 to 5 wt % of the mixture.