Granted Patent
Utility
US 6,720,048 · App. 10/049,621
Pipe comprising ethylene base polymer
Inventors:
Katsutoshi Ohta, Shigeru Murakami, Ryouichi Nakano
Patented Case
View Patent ↗
Granted: Apr 13, 2004
Filed: Feb 22, 2002
Inventors
Katsutoshi Ohta
Shigeru Murakami
Ryouichi Nakano
Assignees (at issue)
Idemitsu Petrochemical Co., Ltd.
Kurimoto, 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.