Granted Patent
Utility
US 5,231,211 · App. 07/947,211
Method for preparing di(organo) esters of pyrocarbonic acid
Inventor:
Robert H. Tang
Patented Case
View Patent ↗
Granted: Jul 27, 1993
Filed: Sep 18, 1992
Inventor
Robert H. Tang
Assignee (at issue)
PPG Industries, 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.