Granted Patent
Utility
US 4,321,276 · App. 06/254,337
Phenylureas
Inventors:
Josef Ehrenfreund, Achim Roloff
Patented Case
View Patent ↗
Granted: Mar 23, 1982
Filed: Apr 14, 1981
Inventors
Josef Ehrenfreund
Achim Roloff
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.