Granted Patent
Utility
US 5,683,749 · App. 08/781,551
Method for preparing asbestos-free chlor-alkali diaphragm
Inventors:
Donald W. DuBois, Colonel R. Dilmore
Patented Case
View Patent ↗
Granted: Nov 4, 1997
Filed: Jan 9, 1997
Inventors
Donald W. DuBois
Colonel R. Dilmore
Assignee (at issue)
PPG Industries, Inc.
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.