Granted Patent
Utility
US 4,957,997 · App. 07/481,425
Process for converting polyketones containing pendant functional groups to polyesters
Inventors:
Biau-Hung Chang, Jack Kwiatek
Patented Case
View Patent ↗
Granted: Sep 18, 1990
Filed: Feb 16, 1990
Inventors
Biau-Hung Chang
Jack Kwiatek
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.