Granted Patent
Utility
US 4,293,480 · App. 06/038,158
Urethane binder compositions for no-bake and cold box foundry application utilizing isocyanato-urethane polymers
Inventors:
Ralph D. Martin, William R. Dunnavant, Gregory P. Sturtz, Heimo J. Langer
Patented Case
View Patent ↗
Granted: Oct 6, 1981
Filed: May 11, 1979
Inventors
Ralph D. Martin
William R. Dunnavant
Gregory P. Sturtz
Heimo J. Langer
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.