Granted Patent
Utility
US 5,368,637 · App. 08/143,619
Water-insoluble sulphur dyes, their preparation and use
Inventors:
Wolfgang Bauer, Willi Steckelberg, Josef Ritter, Wilhelm Mauelshagen
Patented Case
View Patent ↗
Granted: Nov 29, 1994
Filed: Nov 1, 1993
Inventors
Wolfgang Bauer
Willi Steckelberg
Josef Ritter
Wilhelm Mauelshagen
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.