Granted Patent
Utility
US 4,136,042 · App. 05/843,315
Lubricating oils containing dithiophosphorylated copolymers of aziridineethyl acrylates or methacrylates and alkyl acrylates or methacrylates
Inventors:
John P. Pellegrini, Jr., Helen I. Thayer
Patented Case
View Patent ↗
Granted: Jan 23, 1979
Filed: Oct 18, 1977
Inventors
John P. Pellegrini, Jr.
Helen I. Thayer
Assignee (at issue)
Gulf Research & Development 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.