Granted Patent
Utility
US 4,946,876 · App. 07/264,649
Polyurethane-forming foundry binders containing a polyester polyol
Inventors:
William G. Carpenter, William R. Dunnavant
Patented Case
View Patent ↗
Granted: Aug 7, 1990
Filed: Oct 31, 1988
Inventors
William G. Carpenter
William R. Dunnavant
Assignee (at issue)
Ashland Oil, Inc.
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.