Granted Patent
Utility
US 4,444,915 · App. 06/519,274
Rigid polyisocyanurate foam
Inventors:
Louis L. Grube, Charles J. Horner, Jr.
Patented Case
View Patent ↗
Granted: Apr 24, 1984
Filed: Aug 1, 1983
Inventors
Louis L. Grube
Charles J. Horner, Jr.
Assignee (at issue)
GAF 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.