Granted Patent
Utility
US 6,335,421 · App. 09/644,007
Preparation of poly(trimethylene terephthalate) with low level of di(1,3-propylene glycol)
Inventors:
Joseph V. Kurian, Yuanfeng Liang
Patented Case
View Patent ↗
Granted: Jan 1, 2002
Filed: Aug 23, 2000
Inventors
Joseph V. Kurian
Yuanfeng Liang
Assignee (at issue)
E.I. DU PONT DE NEMOURS AND 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.