Granted Patent
Utility
US 5,153,164 · App. 07/354,947
Catalyst system for preparing polyethylene terephthalate
Inventor:
James D. Mason
Patented Case
View Patent ↗
Granted: Oct 6, 1992
Filed: May 22, 1989
Inventor
James D. Mason
Assignee (at issue)
Hoechst Celanese 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.