Patents Assigned to National Patent Development Co.
  • Hydrophilic gels containing high amounts of fragrance
    Patent number: 4587129
    Abstract: A copolymer of at least one hydroxy (lower alkyl) 2-alkenoate, e.g., hydroxyethyl methacrylate, with 35 to 80%, preferably 50 to 80%, of at least one diester of an alkenedioic acid in hydrogel form is employed to entrap flavors and fragrances in an amount of 5 to 80% or even up to 90%, preferably 30 to 80% of the total formulation. A solvent can also be present in an amount up to 80%, preferably 10-80% of the total weight of the formulation.
    Type: Grant
    Filed: June 1, 1982
    Date of Patent: May 6, 1986
    Assignee: National Patent Development Co.
    Inventor: Charles K. Kliment
  • Permeable contact lens
    Patent number: 4388436
    Abstract: A hydrophilic soft contact lens is made from a cross-linked copolymer of an N,N-(C.sub.1 -C.sub.2 alkyl)acrylamide and cyclohexyl methacrylate. The lens has much higher oxygen permeability and better mechanical properties than conventional hydrophilic contact lenses.
    Type: Grant
    Filed: June 8, 1981
    Date of Patent: June 14, 1983
    Assignee: National Patent Development Co.
    Inventor: Richard Chen