Granted Patent
Utility
US 4,923,917 · App. 07/173,691
Tetrahalophthalate esters as flame retardants for styrene-maleic anhydride copolymer (SMA) resins
Inventor:
Joseph M. Bohen
Patented Case
View Patent ↗
Granted: May 8, 1990
Filed: Mar 25, 1988
Inventor
Joseph M. Bohen
Assignee (at issue)
Pennwalt 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.