Granted Patent
Utility
US 5,137,576 · App. 07/414,137
Quinacridones having selectively adjusted triboelectric effects
Inventors:
Hans-Tobias Macholdt, Adolf Kroh, Alexander Sieber, Erwin Dietz
Patented Case
View Patent ↗
Granted: Aug 11, 1992
Filed: Sep 28, 1989
Inventors
Hans-Tobias Macholdt
Adolf Kroh
Alexander Sieber
Erwin Dietz
Assignee (at issue)
Hoechst GmbH
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.