Granted Patent
Utility
US 4,339,348 · App. 06/141,126
Dioxime ion exchangers
Inventors:
Ralph W. M. Lai, John K. Litchfield
Patented Case
View Patent ↗
Granted: Jul 13, 1982
Filed: Apr 17, 1980
Inventors
Ralph W. M. Lai
John K. Litchfield
Assignee (at issue)
Kennecott Holdings Company
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.