Granted Patent
Utility
US 4,983,691 · App. 07/397,221
Reduction of acidity of polyesters by melt reaction endcapping with dialkyloxylate or tetraalkyl urea
Inventors:
William L. Hergenrother, John M. Doshak
Patented Case
View Patent ↗
Granted: Jan 8, 1991
Filed: Aug 23, 1989
Inventors
William L. Hergenrother
John M. Doshak
Assignee (at issue)
Bridgestone Firestone
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.