Granted Patent
Utility
US 4,701,567 · App. 06/878,687
Process for producing 6,6'-dihydroxy-3,3,3',3'-tetramethyl-1,1'-spirobiindane
Inventors:
Yoshimitsu Tanabe, Keizaburo Yamaguchi, Yukihiro Yoshikawa, Kenichi Sugimoto, Akihiro Yamaguchi
Patented Case
View Patent ↗
Granted: Oct 20, 1987
Filed: Jun 26, 1986
Inventors
Yoshimitsu Tanabe
Keizaburo Yamaguchi
Yukihiro Yoshikawa
Kenichi Sugimoto
Akihiro Yamaguchi
Assignee (at issue)
Mitsui Toatsu Chemicals, Incorporated
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.