Granted Patent
Utility
US 4,939,297 · App. 07/361,176
Extraction process for removal of impurities from terephthalic acid filtrate
Inventors:
Larry W. Browder, James C. Medlin, Art T. Spaugh, Jr.
Patented Case
View Patent ↗
Granted: Jul 3, 1990
Filed: Jun 5, 1989
Inventors
Larry W. Browder
James C. Medlin
Art T. Spaugh, Jr.
Assignee (at issue)
EASTMAN KODAK 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.