Granted Patent
Utility
US 4,283,500 · App. 06/135,397
Polymer/polyisocyanates
Inventors:
George H. Armstrong, Richard M. Gerkin, Frank E. Critchfield
Patented Case
View Patent ↗
Granted: Aug 11, 1981
Filed: Mar 31, 1980
Inventors
George H. Armstrong
Richard M. Gerkin
Frank E. Critchfield
Assignee (at issue)
Union Carbide 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.