Granted Patent
Utility
US 4,399,310 · App. 06/303,541
Preparation of 1,3-cyclic diones by vapor phase cyclization of delta-keto carboxylic acid esters utilizing carrier condensable under ambient conditions
Inventor:
Nicholas P. Greco
Patented Case
View Patent ↗
Granted: Aug 16, 1983
Filed: Sep 18, 1981
Inventor
Nicholas P. Greco
Assignee (at issue)
KOPPERS, 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.