Granted Patent
Utility
US 4,415,439 · App. 06/375,235
Catalytic cracking catalyst
Inventor:
Robert L. Chiang
Patented Case
View Patent ↗
Granted: Nov 15, 1983
Filed: May 5, 1982
Inventor
Robert L. Chiang
Assignee (at issue)
W. R. Grace & Co.
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.