Granted Patent
Utility
US 4,881,977 · App. 07/245,897
Water-soluble yellow monoazo dyestuffs
Inventors:
Wolfgang Bauer, Willi Steckelberg, Josef Ritter
Patented Case
View Patent ↗
Granted: Nov 21, 1989
Filed: Sep 19, 1988
Inventors
Wolfgang Bauer
Willi Steckelberg
Josef Ritter
Assignee (at issue)
Cassella Aktiengesellschaft
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.