Granted Patent
Utility
US 4,644,035 · App. 06/677,655
Process for sulfonating of polymers containing dicarboxylic acid cyclic imide units
Inventors:
David C. Dehm, H. Franklin Lawson
Patented Case
View Patent ↗
Granted: Feb 17, 1987
Filed: Dec 3, 1984
Inventors
David C. Dehm
H. Franklin Lawson
Assignee (at issue)
Atlantic Richfield 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.