Granted Patent
Utility
US 4,772,328 · App. 06/943,525
Hydraulic cementitious compositions reinforced with fibers containing polyacrylonitrile
Inventor:
Charles R. Pfeifer
Patented Case
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Granted: Sep 20, 1988
Filed: Dec 18, 1986
Inventor
Charles R. Pfeifer
Assignee (at issue)
BASF SE
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.