Granted Patent
Utility
US 4,988,806 · App. 07/365,612
Nitrogen-containing derivatives of carboxymethylcellulose, their synthesis and their use in cosmetic preparations
Inventors:
Burghard Gruning, Klaus Hoffmann, Gotz Koerner, Hans-Joachim Kollmeier
Patented Case
View Patent ↗
Granted: Jan 29, 1991
Filed: Jun 13, 1989
Inventors
Burghard Gruning
Klaus Hoffmann
Gotz Koerner
Hans-Joachim Kollmeier
Assignee (at issue)
Th. Goldschmidt. AG
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.