Granted Patent
Utility
US 5,185,390 · App. 07/802,927
Water strippable photochromic resin composition
Inventors:
Scott James Fischer, Cletus N. Welch
Patented Case
View Patent ↗
Granted: Feb 9, 1993
Filed: Dec 6, 1991
Inventors
Scott James Fischer
Cletus N. Welch
Assignee (at issue)
PPG Industries, 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.