Granted Patent
Utility
US 4,869,844 · App. 07/323,248
High solids liquid alkaline cleaners
Inventor:
Mark D. Johnson
Patented Case
View Patent ↗
Granted: Sep 26, 1989
Filed: Mar 9, 1989
Inventor
Mark D. Johnson
Assignee (at issue)
Pennwalt Corporation
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.