Granted Patent
Utility
US 6,423,856 · App. 09/644,913
Process for preparing ester plasticizers
Inventors:
Helmut Springer, Klaus Dieter Merscher, Rudolf Heumuller, Klaus Schimmer, Heinz Strutz
Patented Case
View Patent ↗
Granted: Jul 23, 2002
Filed: Aug 24, 2000
Inventors
Helmut Springer
Klaus Dieter Merscher
Rudolf Heumuller
Klaus Schimmer
Heinz Strutz
Assignee (at issue)
CELANESE CHEMICALS EUROPE GMBH
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.