Granted Patent
Utility
US 4,554,020 · App. 06/595,066
Hydraulic cement admixture compositions
Inventor:
David H. Hollenberg
Patented Case
View Patent ↗
Granted: Nov 19, 1985
Filed: Mar 29, 1984
Inventor
David H. Hollenberg
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.