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Hydroxy-substituted polymeric shaped hydrogel article

  • US 4,921,884 A
  • Filed: 08/17/1988
  • Issued: 05/01/1990
  • Est. Priority Date: 02/26/1987
  • Status: Expired due to Term
First Claim
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1. An ophthalmic device prepared by a process comprising the steps:

  • a. thermoforming an uncrosslinked polymer having a softening temperature of at least 100°

    C. comprising the product of at least 95 weight percent of an ethylenically-unsaturated monomer bearing at least one trihaloacetoxy-substituent group, said ethylenically unsaturated monomer being(1) a compound having a formula ##STR2## wherein R is hydrogen or methyl, X is fluoro, chloro, bromo, iodo, perhaloacetoxy or perfluoroalkylsulfonoxy of one to three carbon atoms, and Y is trichloroacetyl or trifluoroacetyl, or(2) vinyl trihaloacetate, by heating said uncrosslinked polymer in a mold or pressing into sheets or films at a temperature in the range of 150°

    to 400°

    C. for 5 seconds to 15 minutes, and then cooling the resulting thermoformed polymer, to provide a thermoplastic, hydrogel precursor ophthalmic device.b. solvolyzing the hydrogel precursor ophthalmic device by reacting with a nucleophile which causes displacement of said trihaloacetoxy group to provide a hyroxy-substituted polymeric ophthalmic device, said solvolyzing step taking place in the presence of a diluent which is not a solvent for said thermoformed polymer, wherein when said polymer is derived from vinyl trihaloacetate it has a syndiotactic stereochemical configuration.

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