Granted Patent
Utility
US 4,375,558 · App. 06/309,962
Purification of methacrylamidopropyltrimethyl-ammonium chloride with nonionic organic resins
Inventors:
Edward E. McEntire, Edward C. Y. Nieh
Patented Case
View Patent ↗
Granted: Mar 1, 1983
Filed: Oct 9, 1981
Inventors
Edward E. McEntire
Edward C. Y. Nieh
Assignee (at issue)
Texaco 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.