Granted Patent
Utility
US 4,256,847 · App. 06/085,724
Rigid polyurethane foam process using lithium/zinc catalyst
Inventor:
Richard J. Spector
Patented Case
View Patent ↗
Granted: Mar 17, 1981
Filed: Oct 17, 1979
Inventor
Richard J. Spector
Assignee (at issue)
Mooney Chemicals, 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.