Granted Patent
Utility
US 4,880,942 · App. 07/222,414
Preparation of cyclic carbonates
Inventors:
Yoshihisa Kiso, Yuuichi Matsunaga, Masao Imagawa
Patented Case
View Patent ↗
Granted: Nov 14, 1989
Filed: Jul 21, 1988
Inventors
Yoshihisa Kiso
Yuuichi Matsunaga
Masao Imagawa
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.