Granted Patent
Utility
US 4,855,413 · App. 07/188,075
Heterocyclic azo dyes containing cyanothiophene derivatives as diazo components and diaminopyridines as coupling components
Inventors:
Johannes Dehnert, Gunther Lamm, Hermann Loeffler
Patented Case
View Patent ↗
Granted: Aug 8, 1989
Filed: Apr 28, 1988
Inventors
Johannes Dehnert
Gunther Lamm
Hermann Loeffler
Assignee (at issue)
BASF SE
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.