Granted Patent
Utility
US 4,812,279 · App. 07/060,799
Process for preparation of cellulose ester films
Inventors:
Hiroaki Nakagawa, Masahiro Kondo, Noriake Ohishi
Patented Case
View Patent ↗
Granted: Mar 14, 1989
Filed: Jun 12, 1987
Inventors
Hiroaki Nakagawa
Masahiro Kondo
Noriake Ohishi
Assignee (at issue)
Mitsui Petrochemical Industries, Ltd.
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.