Granted Patent
Utility
US 5,489,331 · App. 08/270,454
Color changing compositions using acids
Inventors:
Richard E. Miller, Charlene R. Couch
Patented Case
View Patent ↗
Granted: Feb 6, 1996
Filed: Jul 5, 1994
Inventors
Richard E. Miller
Charlene R. Couch
Assignee (at issue)
BINNEY & SMITH 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.