Granted Patent
Utility
US 4,891,153 · App. 07/228,643
Mixtures of fluorescent whitening agents
Inventors:
Leonardo Guglielmetti, Hans R. Meyer, Dieter Reinehr, Kurt Weber
Patented Case
View Patent ↗
Granted: Jan 2, 1990
Filed: Aug 5, 1988
Inventors
Leonardo Guglielmetti
Hans R. Meyer
Dieter Reinehr
Kurt Weber
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.