Granted Patent
Utility
US 4,560,746 · App. 06/677,118
Ultrafiltration process for purification of dyes useful in foodstuffs
Inventors:
Robert W. J. Rebhahn, Wayne Lee Cook
Patented Case
View Patent ↗
Granted: Dec 24, 1985
Filed: Nov 30, 1984
Inventors
Robert W. J. Rebhahn
Wayne Lee Cook
Assignee (at issue)
Hilton Davis Chemical Co.
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.