Granted Patent
Utility
US 5,051,457 · App. 07/553,042
Asphalt-block copolymer roofing composition
Inventor:
Richard Gelles
Patented Case
View Patent ↗
Granted: Sep 24, 1991
Filed: Jul 16, 1990
Inventor
Richard Gelles
Assignee (at issue)
SHELL OIL 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.