Granted Patent
Utility
US 4,970,113 · App. 07/339,489
Multilayer structure and easily openable container and lid
Inventor:
Toyokazu Yamada
Patented Case
View Patent ↗
Granted: Nov 13, 1990
Filed: Apr 17, 1989
Inventor
Toyokazu Yamada
Assignee (at issue)
Idemitsu Petrochemical 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.