Granted Patent
Utility
US 5,292,804 · App. 07/764,412
Separation of azeotropes in poly(vinyl alcohol) process
Inventor:
Michael S. Chen
Patented Case
View Patent ↗
Granted: Mar 8, 1994
Filed: Sep 23, 1991
Inventor
Michael S. Chen
Assignee (at issue)
Air Products and Chemicals, Inc.
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.