Granted Patent
Utility
US 6,750,337 · App. 10/052,362
Couplers for use in oxidative hair dyeing
Inventors:
Mu-Ill Lim, Yuh-Guo Pan, Gottfried Wenke
Patented Case
View Patent ↗
Granted: Jun 15, 2004
Filed: Jan 18, 2002
Inventors
Mu-Ill Lim
Yuh-Guo Pan
Gottfried Wenke
Assignee (at issue)
The Procter & Gamble Company
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.