Granted Patent
Utility
US 4,540,781 · App. 06/522,127
Product and process trimerization of organic isocyanates
Inventor:
Edward A. Barsa
Patented Case
View Patent ↗
Granted: Sep 10, 1985
Filed: Aug 11, 1983
Inventor
Edward A. Barsa
Assignee (at issue)
The Upjohn Co.
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.