Granted Patent
Utility
US 6,290,772 · App. 09/524,803
Processing additives for hydraulic cements
Inventors:
Josephine H. Cheung, David F. Myers
Patented Case
View Patent ↗
Granted: Sep 18, 2001
Filed: Sep 30, 1999
Inventors
Josephine H. Cheung
David F. Myers
Assignee (at issue)
W.R. Grace & Co. Conn.
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.