Granted Patent
Utility
US 4,560,480 · App. 06/503,485
Process for converting sparingly soluble salts of anionic dyes and fluorescent brighteners into more soluble salts by means of cation exchange
Inventors:
Roger Lacroix, Hans-Rudolf Marfurt
Patented Case
View Patent ↗
Granted: Dec 24, 1985
Filed: Jun 13, 1983
Inventors
Roger Lacroix
Hans-Rudolf Marfurt
Assignee (at issue)
Ciba-Geigy
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.