Granted Patent
Utility
US 4,886,880 · App. 07/212,534
Process for the preparation of triphendioxazines
Inventors:
Holger Hahn, Rudolf Blattner
Patented Case
View Patent ↗
Granted: Dec 12, 1989
Filed: Jun 28, 1988
Inventors
Holger Hahn
Rudolf Blattner
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.