Granted Patent
Utility
US 5,221,343 · App. 07/867,257
Dispersant, setting retarder and air entrainment additive for cement
Inventors:
Zvi Grauer, Steven W. Rogers, Jose L. Villa
Patented Case
View Patent ↗
Granted: Jun 22, 1993
Filed: Apr 10, 1992
Inventors
Zvi Grauer
Steven W. Rogers
Jose L. Villa
Assignee (at issue)
Henkel Limited
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.