Nitrogen Or Oxygen Bonded Directly To The Carbon Of The -c(=o)o- Group (e.g., Diethyl Carbonate, Dodecyl Phenylcarbamate, Octyl Carbanilate, Urethane, Etc.) Patents (Class 106/169.4)
  • Method for making transparent polythiourethane substrates in particular optical substrates
    Patent number: 6887401
    Abstract: A method of fast curing polythiourethane transparent casted substrate, usable for making optical articles such as ophthalmic lenses, which comprises the steps of: 1) Providing a first component A comprising a polythiourethane prepolymer having isocyanate or isothiocyanate end groups and a viscosity at 25° C. ranging from 0.02 to 0.4 Pa.s; 2) Providing a second component B comprising a polythiourethane prepolymer having thiol (SH) end groups and a viscosity at 25° C. ranging from 0.2 to 2.0 Pa.s; 3) Mixing together first and second components A and B and filling a moulding cavity of a casting mould assembly with the resulting mixture; 4) Curing said mixture to obtain a transparent solid substrate, said curing step comprising: a) a first step for polymerizing said mixture to obtain a gel within 1 to 10 minutes; and b) a second step of post-curing the gel to obtain the transparent solid substrate; and 5) Recovering the transparent solid substrate from the mould.
    Type: Grant
    Filed: November 5, 2001
    Date of Patent: May 3, 2005
    Assignee: Essilor International Compagnie General d'Optique
    Inventors: Gabriel Keita, Joey O. Obordo, Pamela Anne McClimans, Yassin Yusef Turshani
  • Aqueous dispersions of hydrophilic polyurethane resins
    Publication number: 20030049457
    Abstract: An aqueous polyurethane resin dispersions containing
    Type: Application
    Filed: August 5, 2002
    Publication date: March 13, 2003
    Inventors: Thomas Munzmay, Uwe Klippert, Frank Kobor, Claus Kobusch, Gerald Kurek