Granted Patent
Utility
US 5,162,488 · App. 07/705,871
Catalyst system and process for preparing polyethylene terephthalate
Inventor:
James D. Mason
Patented Case
View Patent ↗
Granted: Nov 10, 1992
Filed: May 28, 1991
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.