Patents by Inventor Won S. Kwak

Won S. Kwak has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Photochromic compound and articles containing the same
    Patent number: 4931219
    Abstract: Described are spiro (benzidoline) pyrido benzoxazine and spiro (benzindoline) naphthoxazine photochromic compounds and their use in plastic hosts to impact a photochromic response thereto.
    Type: Grant
    Filed: June 12, 1989
    Date of Patent: June 5, 1990
    Assignee: PPG Industries, Inc.
    Inventors: Patricia L. Kwiatkowski, Won S. Kwak
  • Photochromic article
    Patent number: 4909963
    Abstract: Described are photochromic spiro(indoline)benzoxazine compounds having substituents on the benzoxazine portion of the compound, and their use in plastic hosts to impart a photochromic response thereto.
    Type: Grant
    Filed: December 6, 1988
    Date of Patent: March 20, 1990
    Assignee: PPG Industries, Inc.
    Inventors: Won S. Kwak, Chin-Wen Chen
  • Spiro indoline-pyranobenzoxazinones
    Patent number: 4831142
    Abstract: Photochromic spiro-oxizine compounds are prepared by mixing in a substantially non-reactive organic solvent medium an alkylidene heterocyclic compound or halide salt thereof, e.g., an indoline, with a metal chelate of an ortho-hydroxynitrosoaromatic compound.
    Type: Grant
    Filed: September 28, 1988
    Date of Patent: May 16, 1989
    Assignee: PPG Industries, Inc.
    Inventor: Won S. Kwak
  • Photochromic spiro(indoline)benzoxazines
    Patent number: 4816584
    Abstract: Described are photochromic spiro(indoline)benzoxazine compounds having substituents on the benzoxazine portion of the compound, and their use in plastic hosts to impart a photochromic response thereto.
    Type: Grant
    Filed: July 23, 1987
    Date of Patent: March 28, 1989
    Assignee: PPG Industries, Inc.
    Inventors: Won S. Kwak, Chin-Wen Chen
  • Method for synthesizing spiro-oxazines
    Patent number: 4785097
    Abstract: Photochromic spiro-oxizine compounds are prepared by mixing in a substantially non-reactive organic solvent medium an alkylidene heterocyclic compound or halide salt thereof, e.g., an indoline, with a metal chelate of an ortho-hydroxynitrosoaromatic compound.
    Type: Grant
    Filed: September 26, 1986
    Date of Patent: November 15, 1988
    Assignee: PPG Industries, Inc.
    Inventor: Won S. Kwak
  • Photochromic compound and articles containing the same
    Patent number: 4720547
    Abstract: Described are photochromic spiro[indoline-2,3'[3H] pyrido [3,2-f][1,4]-benzoxazine compounds having a C.sub.1 -C.sub.4 monohaloalkyl or C.sub.1 -C.sub.4 polyhaloalkyl substituent on the indoline ring, and their use in plastic hosts to impart a photochromic response thereto.
    Type: Grant
    Filed: February 5, 1986
    Date of Patent: January 19, 1988
    Assignee: PPG Industries, Inc.
    Inventors: Won S. Kwak, Rodney J. Hurditch
  • Photochromic compound and articles containing the same
    Patent number: 4637698
    Abstract: Photochromic compounds represented by the graphic formula: ##STR1## wherein: (a) R.sub.1 is selected from the group consisting of C.sub.1 -C.sub.8 alkyl, phenyl, phen(C.sub.1 -C.sub.4) alkyl, allyl and mono- and di-substituted phenyl, said substituents being selected from C.sub.1 -C.sub.4 alkyl and C.sub.1 -C.sub.5 alkoxy;(b) R.sub.2 and R.sub.3 are each selected from the group consisting of C.sub.1 -C.sub.5 alkyl, phenyl, C.sub.1 -C.sub.4 alkyl and C.sub.1 -C.sub.5 alkoxy mono- and disubstituted phenyl, benzyl or combined to form a cyclic ring selected from the group consisting of an alicyclic ring containing from 6 to 8 carbon atoms (including the spiro carbon atom), norbornyl and adamantyl, and(c) R.sub.4 and R.sub.5 are each selected from the group consisting of hydrogen, C.sub.1 -C.sub.5 alkyl, halogen, C.sub.1 -C.sub.5 alkoxy, nitro, cyano and C.sub.1 -C.sub.8 alkoxycarbonylare described.
    Type: Grant
    Filed: July 30, 1984
    Date of Patent: January 20, 1987
    Assignee: PPG Industries, Inc.
    Inventors: Won S. Kwak, Rodney J. Hurditch