Granted Patent
Utility
US 4,656,302 · App. 06/709,658
Tris-(3-hydroxy-4,6-di-t-alkylphenyl) phosphites
Inventor:
Hans Dressler
Patented Case
View Patent ↗
Granted: Apr 7, 1987
Filed: Mar 8, 1985
Inventor
Hans Dressler
Assignee (at issue)
KOPPERS, 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.