Granted Patent
Utility
US 5,646,235 · App. 08/665,989
Reductive alkylation of polyamines
Inventors:
Robert L. Zimmerman, Wheeler C. Crawford, Rodney F. Lloyd
Patented Case
View Patent ↗
Granted: Jul 8, 1997
Filed: Jun 18, 1996
Inventors
Robert L. Zimmerman
Wheeler C. Crawford
Rodney F. Lloyd
Assignee (at issue)
HUNTSMAN PETROCHEMICAL LLC
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.