Granted Patent
Utility
US 4,987,110 · App. 07/359,112
Attrition resistant cracking catalyst
Inventor:
Julius Scherzer
Patented Case
View Patent ↗
Granted: Jan 22, 1991
Filed: May 31, 1989
Inventor
Julius Scherzer
Assignee (at issue)
Union Oil Company of California
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.