Granted Patent
Utility
US 5,347,022 · App. 08/038,865
Preparation of DI- or triarylmethane dyes by oxidation
Inventors:
Thomas Gessner, Udo Mayer
Patented Case
View Patent ↗
Granted: Sep 13, 1994
Filed: Mar 29, 1993
Inventors
Thomas Gessner
Udo Mayer
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.