Granted Patent
Utility
US 4,520,208 · App. 06/505,494
Aromatic polyester containing phenolphthalein unit and bis-phenol unit
Inventors:
Masahiro Hayashi, Seiichi Nozawa, Takashi Oikawa
Patented Case
View Patent ↗
Granted: May 28, 1985
Filed: Jun 17, 1983
Inventors
Masahiro Hayashi
Seiichi Nozawa
Takashi Oikawa
Assignee (at issue)
Mitsubishi Chemical 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.