Granted Patent
Utility
US 5,691,050 · App. 08/450,076
Concrete molding with improved acid resistance
Inventors:
Volkmar Berg, Helmut Rinno
Patented Case
View Patent ↗
Granted: Nov 25, 1997
Filed: May 25, 1995
Inventors
Volkmar Berg
Helmut Rinno
Assignee (at issue)
Hoechst GmbH
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.