Granted Patent
Utility
US 5,243,032 · App. 07/781,257
Preparation of azo pigments with low PCB content by coupling in the presence of olefins
Inventor:
Wolfgang Rieper
Patented Case
View Patent ↗
Granted: Sep 7, 1993
Filed: Feb 21, 1992
Inventor
Wolfgang Rieper
Assignee (at issue)
Hoechst GmbH
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.