Granted Patent
Utility
US 4,230,762 · App. 06/059,326
Asphalt water-proofing material
Inventors:
Hajime Iwasaki, Kuninori Mizuta, Yoshinori Kobayashi, Tadayoshi Yoshikawa, Kyouzi Muraoka
Patented Case
View Patent ↗
Granted: Oct 28, 1980
Filed: Jul 20, 1979
Inventors
Hajime Iwasaki
Kuninori Mizuta
Yoshinori Kobayashi
Tadayoshi Yoshikawa
Kyouzi Muraoka
Assignees (at issue)
Mitsui Petrochemical Industries, Ltd.
Mitsuboshi Sangyo 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.