Granted Patent
Utility
US 5,091,002 · App. 07/492,086
Preparation for the water-repellent impregnation of porous mineral building materials
Inventors:
Eckehard Schamberg, Gotz Koerner, Herwig Fritsch, Manfred Grasse, Roland Sucker
Patented Case
View Patent ↗
Granted: Feb 25, 1992
Filed: Mar 12, 1990
Inventors
Eckehard Schamberg
Gotz Koerner
Herwig Fritsch
Manfred Grasse
Roland Sucker
Assignee (at issue)
Th. Goldschmidt. AG
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.