Granted Patent
Utility
US 4,826,503 · App. 06/917,348
Process for aftertreating cellulosic material dyed with dyes containing acid sulfo groups with salt solution to improve wet fastness and tear strength
Inventor:
Jean-Francois Landre
Patented Case
View Patent ↗
Granted: May 2, 1989
Filed: Oct 9, 1986
Inventor
Jean-Francois Landre
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.