Granted Patent
Utility
US 5,032,237 · App. 07/397,281
Anodic phosphonic/phosphinic acid duplex coating on valve metal surface
Inventors:
Larry F. Wieserman, Karl Wefers, Gary A. Nitowski, Edward S. Martin
Patented Case
View Patent ↗
Granted: Jul 16, 1991
Filed: Aug 23, 1989
Inventors
Larry F. Wieserman
Karl Wefers
Gary A. Nitowski
Edward S. Martin
Assignee (at issue)
Aluminum Company of America
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.