Granted Patent
Utility
US 4,391,985 · App. 06/321,948
Process for the separation of isophthalic acid from terephthalic acid
Inventors:
Richard J. Hook, Mark Rule
Patented Case
View Patent ↗
Granted: Jul 5, 1983
Filed: Nov 16, 1981
Inventors
Richard J. Hook
Mark Rule
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.