Granted Patent
Utility
US 5,518,657 · App. 08/278,708
Storage-stable formulation of fluorescent whitening mixtures
Inventors:
Werner Fringeli, Josef Zelger
Patented Case
View Patent ↗
Granted: May 21, 1996
Filed: Jul 22, 1994
Inventors
Werner Fringeli
Josef Zelger
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.