摘要 |
A cross-linked, hydrogel polymer for contact lenses with a water uptake of between 60 and 70% by weight based on the total weight of hydrogel is formed from a mixture of monomer components containing (1) N-vinyl-2-pyrrolidone, (2) alkyl methacrylate and (3) a compound of formula <IMAGE> in which R1 is hydrogen or a lower alkyl group, preferably methyl, and R2 is either a substituted or unsubstituted aryl group or an alkyl group containing from 1 to 6 carbon atoms substituted by a substituted or unsubstituted aryl group or a substituted or unsubstituted aryloxygroup or by a cycloalkyloxygroup. Preferably the alkyl methacrylate is hydroxyethyl methacrylate and the third component phenethyl methacrylate. Cross-linking agents used preferably have their two functional groups differing in reactivity, for example allyl methacrylate.
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