Granted Patent
Utility
US 5,166,311 · App. 07/653,389
Catalyst system and process for preparing high clarity, colorless polyethylene terephthalate
Inventor:
Carl Steven Nichols
Patented Case
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Granted: Nov 24, 1992
Filed: Feb 11, 1991
Inventor
Carl Steven Nichols
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.