Granted Patent
Utility
US 4,643,362 · App. 06/803,380
Grinding aids for hydraulic cement
Inventor:
Frank G. Serafin
Patented Case
View Patent ↗
Granted: Feb 17, 1987
Filed: Dec 2, 1985
Inventor
Frank G. Serafin
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.