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High refractive index ophthalmic device materials prepared using a post-polymerization cross-linking method

  • US 6,313,187 B2
  • Filed: 01/19/2001
  • Issued: 11/06/2001
  • Est. Priority Date: 04/15/1998
  • Status: Expired due to Term
First Claim
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1. A two-stage method for preparing an acrylic, high refractive index ophthalmic device material, wherein the ophthalmic device material comprises(i) at least two aryl acrylic hydrophobic monomers of the formula

  • wherein;

    X is H or CH3;

    m is 0-10;

    Y is nothing, O, S, or NR wherein R is H, CH3, CnH2n+1 (n=1-10) iso OC3H7, C6H5, or CH2C6H5;

    Ar is any aromatic ring which can be unsubstituted or substituted with CH3, C2H5, n-C3H7, iso-C3H7, OCH3, C6H11, Cl, Br, C6H5, or CH2C6H5;

    and further wherein at least one of the aryl acrylic hydrophobic monomers is a methacrylate monomer and at least one of the aryl acrylic hydrophobic monomers is an acrylate monomer;

    (ii) a first stage polymerization initiator selected from the group consisting of photoinitiators and thermal free radical initiators having a 10 hr t½

    of about 55°

    C. or less; and

    (iii) a second stage cross-linking agent where the second stage cross-linking agent is a thermal free radical initiator having a 10 hr t½

    of about 50°

    C. or greater if the first stage polymerization initiator is a photoinitiator and the second stage cross-linking agent is a thermal free radical initiator having a 10 hr t½

    of about 65°

    C. or greater if the first stage polymerization initiator is a thermal free radical initiator having a 10 hr t½

    of about 55°

    C. or less, wherein the first stage of the method comprises polymerizing the ophthalmic device material by activating the first stage polymerization initiator without activating the second stage cross-linking agent; and

    the second stage of the method comprises cross-linking the ophthalmic device material by activating the second stage cross-linking agent.

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