Granted Patent
Utility
US 5,248,821 · App. 07/846,986
Process for preparing polyoxyethylene amines with urea linkages
Inventors:
Jiang-Jen Lin, George P. Speranza
Patented Case
View Patent ↗
Granted: Sep 28, 1993
Filed: Mar 9, 1992
Inventors
Jiang-Jen Lin
George P. Speranza
Assignee (at issue)
Texaco 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.