Granted Patent
Utility
US 5,153,156 · App. 07/766,938
Process for making efficient anionic clay catalyst, catalysts made thereby, and method of making isophorone
Inventors:
Alain Schutz, Leonard A. Cullo
Patented Case
View Patent ↗
Granted: Oct 6, 1992
Filed: Sep 27, 1991
Inventors
Alain Schutz
Leonard A. Cullo
Assignee (at issue)
Aristech Chemical Company
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.