Granted Patent
Utility
US 5,219,971 · App. 07/822,200
Process for the preparation of fine-particle, water-swellable polysaccharide graft copolymers
Inventors:
Klaus Heidel, Frank Zimmermann
Patented Case
View Patent ↗
Granted: Jun 15, 1993
Filed: Jan 17, 1992
Inventors
Klaus Heidel
Frank Zimmermann
Assignee (at issue)
Starchem, 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.