Patents Assigned to Nori Y. C. Chu
  • Patent number: 4012232
    Abstract: Organic photochromic materials comprise a photochromic pigment stabilized with a protective inorganic coating which serves to protect the pigments from deactivation by exposure to moisture, oxygen, various plastic host materials, reactive chemicals or even normal atmospheric conditions. Useful organic photochromic pigments include the anils, hydrazones, semicarbozones, osazones, sydnones, fulgides and others. Inorganic coatings comprising such materials as zinc oxide, titanium dioxide, aluminum oxide, antimony oxide and silicon dioxide are useful in the preparation of photochromic plastic films, sheets, ophthalmic lenses such as lenses for sunglasses and in camera lenses and filters.
    Type: Grant
    Filed: December 23, 1974
    Date of Patent: March 15, 1977
    Assignee: Nori Y. C. Chu
    Inventors: Donald R. Uhlmann, Elias Snitzer, Richard J. Hovey, Nori Y.C. Chu, Joseph T. Fournier, Jr.