Granted Patent
Utility
US 4,816,590 · App. 06/935,911
Pyrazoline compounds and method of whitening
Inventor:
Hans R. Meyer
Patented Case
View Patent ↗
Granted: Mar 28, 1989
Filed: Nov 28, 1986
Inventor
Hans R. Meyer
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.