Granted Patent
Utility
US 5,200,528 · App. 07/870,986
Diketopyrrolopyrroles
Inventors:
Gary Wooden, Guy de Weck, Olof Wallquist
Patented Case
View Patent ↗
Granted: Apr 6, 1993
Filed: Apr 20, 1992
Inventors
Gary Wooden
Guy de Weck
Olof Wallquist
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.