Granted Patent
Utility
US 4,317,923 · App. 06/189,386
Purification of dicarboxylic aromatic acids
Inventor:
Tamotsu Imai
Patented Case
View Patent ↗
Granted: Mar 2, 1982
Filed: Sep 19, 1980
Inventor
Tamotsu Imai
Assignee (at issue)
UOP LLC
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.