Granted Patent
Utility
US 4,411,820 · App. 06/255,695
Catalyst and process for preparing organic urethanes
Inventors:
Wayne R. Pretzer, Richard B. Pannell
Patented Case
View Patent ↗
Granted: Oct 25, 1983
Filed: Apr 20, 1981
Inventors
Wayne R. Pretzer
Richard B. Pannell
Assignee (at issue)
Gulf Research & Development Company
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.