Granted Patent
Utility
US 4,861,380 · App. 07/263,985
Composition
Inventors:
Frederick Campbell, John M. Geary, John D. Schofield
Patented Case
View Patent ↗
Granted: Aug 29, 1989
Filed: Oct 27, 1988
Inventors
Frederick Campbell
John M. Geary
John D. Schofield
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.