Granted Patent
Utility
US 5,696,258 · App. 08/744,422
Process for the preparation of triphendioxazine dyestuffs amidated on both sides
Inventors:
Christian Schumacher, Karl-Josef Herd
Patented Case
View Patent ↗
Granted: Dec 9, 1997
Filed: Nov 8, 1996
Inventors
Christian Schumacher
Karl-Josef Herd
Assignee (at issue)
Dy Star Textilfarben GmbH & Co.
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.