Granted Patent
Utility
US 6,187,444 · App. 09/083,376
Photochromic polyurethane coating and articles having such a coating
Inventors:
Robert J. Bowles, III, Nancyanne Gruchacz, Shanti Swarup, Jeanine A. Conklin, Robert W. Walters, Robin Hunt
Patented Case
View Patent ↗
Granted: Feb 13, 2001
Filed: May 22, 1998
Inventors
Robert J. Bowles, III
Nancyanne Gruchacz
Shanti Swarup
Jeanine A. Conklin
Robert W. Walters
Robin Hunt
Assignee (at issue)
PPG Industries Ohio, Inc.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.