Granted Patent
Utility
US 4,707,524 · App. 06/860,356
Controlled-rheology polypropylene
Inventors:
Raymond J. Ehrig, Richard C. Weil
Patented Case
View Patent ↗
Granted: Nov 17, 1987
Filed: May 6, 1986
Inventors
Raymond J. Ehrig
Richard C. Weil
Assignee (at issue)
Aristech Chemical 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.