Granted Patent
Utility
US 6,414,159 · App. 09/779,743
Method for preparation of a quaternary ammonium salt
Inventors:
Kimihiko Sano, Yoji Urano, Takuhiro Kimura, Atsunori Sano
Patented Case
View Patent ↗
Granted: Jul 2, 2002
Filed: Feb 9, 2001
Inventors
Kimihiko Sano
Yoji Urano
Takuhiro Kimura
Atsunori Sano
Assignee (at issue)
WAKO PURE CHEMICAL 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.