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Polymeric compositions useful in oxygen permeable contact lenses

  • US 5,032,658 A
  • Filed: 10/17/1989
  • Issued: 07/16/1991
  • Est. Priority Date: 10/17/1989
  • Status: Expired due to Term
First Claim
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1. A contact lens material formed from the free radical polymerization of a contact lens organic material and a carboxylic acid ester derived from at least one alcohol which is devoid of beta hydrogens in an amount predetermined to provide both a desired hardness value and oxygen permeability to said contact lens material, wherein said ester has the following formula:

  • ##STR14## wherein A is selected from the group consisting of mesaconic acid, itaconic acid, citraconic acid, methylene malonate, maleic acid, fumaric acid, ethylene tricarboxylic acid, acrylic acid, and methacrylic acid,n=1, 2 or 3,R1, R2 and R3 are the same or different and each are alkyl, cycloalkyl or aryl groups having from 1 to 10 carbon atoms or ether groups having from 2 to 10 carbon atoms,where when A is derived from a dibasic or tribasic acid, the ester can be a full ester, half ester, partial ester or can be a mixed ester, said ester being derived from at least one alcohol which is devoid of beta hydrogens,said material having a Shore D hardness of at least 70 and a DK of at least 10.

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