Granted Patent
Utility
US 4,381,256 · App. 06/225,076
Method of producing binderless zeolite extrudates
Inventor:
Darrell E. Hildebrandt
Patented Case
View Patent ↗
Granted: Apr 26, 1983
Filed: Jan 14, 1981
Inventor
Darrell E. Hildebrandt
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.