Granted Patent
Utility
US 5,035,802 · App. 07/607,283
Membrane filter material having excellent organic solvent resistance, method for formation of membrane filter and process for preparation of bismaleimide polymer to be used for membrane filter
Inventors:
Kazuyuki Yamasaki, Kimio Yamamoto, Masanobu Watanabe, Kojiro Kan, Yoshio Nakayama
Patented Case
View Patent ↗
Granted: Jul 30, 1991
Filed: Oct 31, 1990
Inventors
Kazuyuki Yamasaki
Kimio Yamamoto
Masanobu Watanabe
Kojiro Kan
Yoshio Nakayama
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.