Granted Patent
Utility
US 4,933,426 · App. 07/323,896
Condensation polymers
Inventors:
Robert D. McClelland, Brian Parton
Patented Case
View Patent ↗
Granted: Jun 12, 1990
Filed: Mar 15, 1989
Inventors
Robert D. McClelland
Brian Parton
Assignee (at issue)
IMPERIAL CHEMICAL INDUSTRIES LIMITED
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.