Granted Patent
Utility
US 5,616,783 · App. 08/535,638
Purification process of polyhydroxycarboxylic acid
Inventors:
Yasunori Yoshida, Katsuji Watanabe, Shoji Obuchi, Masahiro Ohta
Patented Case
View Patent ↗
Granted: Apr 1, 1997
Filed: Sep 28, 1995
Inventors
Yasunori Yoshida
Katsuji Watanabe
Shoji Obuchi
Masahiro Ohta
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.