Granted Patent
Utility
US 4,894,432 · App. 07/227,773
Polycarbonate polymer from tetra arylene triphenol
Inventors:
Kenichi Mizuno, Yozo Jujo, Hajime Oyoshi
Patented Case
View Patent ↗
Granted: Jan 16, 1990
Filed: Aug 3, 1988
Inventors
Kenichi Mizuno
Yozo Jujo
Hajime Oyoshi
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.