Granted Patent
Utility
US 5,646,299 · App. 08/493,776
Two new crystal modifications of a diketopyrrolopyrrole pigment
Inventors:
Zhimin Hao, Abul Iqbal, Fritz Herren
Patented Case
View Patent ↗
Granted: Jul 8, 1997
Filed: Jun 22, 1995
Inventors
Zhimin Hao
Abul Iqbal
Fritz Herren
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.