Granted Patent
Utility
US 4,540,716 · App. 06/457,580
Method for making finely divided perfluorocarbon copolymer
Inventors:
Michael J. Covitch, Gary Sweetapple
Patented Case
View Patent ↗
Granted: Sep 10, 1985
Filed: Jan 13, 1983
Inventors
Michael J. Covitch
Gary Sweetapple
Assignee (at issue)
Diamond Shamrock Chemicals Company
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.