Granted Patent
Utility
US 4,239,855 · App. 05/927,244
Polyurethane catalysts and method of use
Inventor:
Robert L. Zimmerman
Patented Case
View Patent ↗
Granted: Dec 16, 1980
Filed: Jul 21, 1978
Inventor
Robert L. Zimmerman
Assignee (at issue)
Texaco Development Corporation
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.