Granted Patent
Utility
US 5,140,080 · App. 07/774,028
Process for converting polyketones to poly(keto-esters)
Inventor:
Biau-Hung Chang
Patented Case
View Patent ↗
Granted: Aug 18, 1992
Filed: Oct 10, 1991
Inventor
Biau-Hung Chang
Assignee (at issue)
Quantum Chemical Corporation
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.