Granted Patent
Utility
US 4,490,542 · App. 06/519,170
1,4-Diketo-pyrrolo[3,4-c]pyrroles
Inventors:
Abul Iqbal, Luigi Cassar
Patented Case
View Patent ↗
Granted: Dec 25, 1984
Filed: Aug 1, 1983
Inventors
Abul Iqbal
Luigi Cassar
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.