| 摘要 |
Organic aprotic solvent soluble polymers which are derivatives of a polyvinyl alcohol, having a weight average molecular weight of at least about 2,000, and containing from about 0.5 to about 90 percent, based on the number of hydroxyl groups in said polyvinyl alcohol, of units of the formula <IMAGE> (I) wherein R1 and R2 are independently alkylene, arylene, cycloaliphatic, aralkylene or aralkarylene, n is 0 or 1, A1 is a carbamoyloxy or ureido linking group, A is an oxa, imino or ureido group, R3 is hydrogen or methyl, R4 is hydrogen, or when R3 is hydrogen, methyl or also -COOR5 where R5 is hydrogen or lower alkyl, and crosslinked hydrogel contact lenses made therefrom and their preparation.
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