| 摘要 |
There is prepared a hydrophilic water swellable, water insoluble copolymer of (1) at least 35% of a hydroxy (C2-C4-alkyl)-2-alkenoate, (2) 30 to 60% of a 2-alkenamide or an N, N-di (C1-C6-alkyl)2-alkenamide, (3) 5 to 20% of R -OR1-xZ where R is C1-C6 alkyl, R1 is C2-C4 alkylene, x is an integer of 1 to 4 and Z is 2-alkenoyloxy and (4) 0.3 to 5% of a polyethylenically unsaturated crosslinking agent having a relatively long aliphatic chain, the copolymer being capable of holding 50 to 80 weight % of water. The polymers are particularly useful in preparing hydrophilic contact lenses of high burst strength and extended wear properties.
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