Hydrophilic gel terpolymers from hydrophilic N-vinyl monomers, hydroxyalkyl acrylates or methacrylates and polymerizable unsaturated carboxylic acids

摘要

A hydrophilic terpolymer suitable for manufacture into shaped articles, said terpolymer being substantially the polymerization product of hydroxyalkyl acrylate or methacrylate, a vinyl comonomer having a high affinity for water, e.g. N-vinyl pyrrolidone, and a polymerizable, unsaturated carboxylic acid, e.g. methacrylic or acrylic acid. The terpolymer is particularly adaptable for use as a contact lens by bringing it in contact with a buffered aqueous alkaline solution thereby affording a hydrogel having a water content between about 55-85% by weight of the total.PPA preferred embodiment of the invention is the polymerization product of a reaction mixture comprising 30-50% by weight of vinyl pyrrolidone, up to about 3% of a crosslinking agent such as ethylene glycol di-methacrylate, methacrylic acid amounting to about 0.25--3.5% by weight, and 2-hydroxyethyl methacrylate which constitutes the balance.