Granted Patent
Utility
US 5,420,344 · App. 08/134,907
Process for producing highly pure terephthalic acid
Inventors:
Yoshiaki Izumisawa, Tsukasa Kawahara, Yoshiyuki Sumi, Takehiko Baba, Yoshio Ishinaga, Katsuhiko Fukui, Hironori Ohgi
Patented Case
View Patent ↗
Granted: May 30, 1995
Filed: Oct 13, 1993
Inventors
Yoshiaki Izumisawa
Tsukasa Kawahara
Yoshiyuki Sumi
Takehiko Baba
Yoshio Ishinaga
Katsuhiko Fukui
Hironori Ohgi
Assignee (at issue)
MITSUBISHI CHEMICAL CORPORATION
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.