Granted Patent
Utility
US 5,130,004 · App. 07/481,812
Pigment grinding vehicles containing quaternary ammonium and ternary sulfonium groups
Inventors:
Mark W. Johnson, Gregory J. McCollum
Patented Case
View Patent ↗
Granted: Jul 14, 1992
Filed: Feb 20, 1990
Inventors
Mark W. Johnson
Gregory J. McCollum
Assignee (at issue)
PPG Industries, Inc.
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.