Granted Patent
Utility
US 5,681,791 · App. 08/501,690
Color former mixture
Inventors:
Rudolf Zink, Klaus Huber
Patented Case
View Patent ↗
Granted: Oct 28, 1997
Filed: Jul 12, 1995
Inventors
Rudolf Zink
Klaus Huber
Assignee (at issue)
Ciba-Geigy
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.