Granted Patent
Utility
US 5,744,578 · App. 08/832,411
Process for the crystallization of polyethylene naphthalate prepolymers and the solid stating of those crystallized prepolymers
Inventor:
Ben Duh
Patented Case
View Patent ↗
Granted: Apr 28, 1998
Filed: Apr 2, 1997
Inventor
Ben Duh
Assignee (at issue)
SHELL OIL 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.