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Material for use in the manufacture of polymeric articles

  • US 5,498,681 A
  • Filed: 02/21/1995
  • Issued: 03/12/1996
  • Est. Priority Date: 01/28/1993
  • Status: Expired due to Fees
First Claim
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1. A hydrogel copolymer composition having a water content of from about 45 to about 56 weight percent, which hydrogel is formed from a xerogel which is a copolymer system that can be solvolyzed and hydrated and which, during solvolysis and hydration, said xerogel composition will undergo a linear expansion of between about -7 and about +7 percent, wherein said composition, prior to solvolysis and hydration, comprises:

  • (a) from about 90 to about 97 weight percent of a single trichloroacetate ester as the only solvolyzable monomer employed which trichloroacetate ester is selected from the group consisting of glyceryl acrylate, methacrylate and ethacrylate of formula I;

    ##STR4## wherein R is selected from the group consisting of hydrogen, methyl and ethyl; and

    (b) from about 0.5 to 10 weight percent of at least one compatible ethylenically unsaturated monomer wherein said monomer is free of solvolyzable leaving groupswherein the weight percent of each of these components is based on the total weight of the composition.

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