Granted Patent
Utility
US 4,239,921 · App. 06/056,231
Process for purification of crude resorcinol
Inventors:
Isao Hashimoto, Hiroaki Nakagawa, Toru Taguchi, Hirohiko Nambu
Patented Case
View Patent ↗
Granted: Dec 16, 1980
Filed: Jul 10, 1979
Inventors
Isao Hashimoto
Hiroaki Nakagawa
Toru Taguchi
Hirohiko Nambu
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.