Granted Patent
Utility
US 5,487,425 · App. 08/310,486
Composition and method for recovery of petroleum and gas
Inventors:
Takamasa Ohno, Keietsu Kato, Yoshiyuki Yamaguchi, Masami Murakami, Shogo Suzuki, Shoichi Kanda, Tsuyoshi Nakagawa
Patented Case
View Patent ↗
Granted: Jan 30, 1996
Filed: Sep 22, 1994
Inventors
Takamasa Ohno
Keietsu Kato
Yoshiyuki Yamaguchi
Masami Murakami
Shogo Suzuki
Shoichi Kanda
Tsuyoshi Nakagawa
Assignees (at issue)
Nitto Chemical Industry Co., Ltd.
JAPAN PETROLEUM EXPLORATION CO., 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.