Granted Patent
Utility
US 4,889,883 · App. 07/047,527
Use of phenol-mercaptocarboxylic acid esters as stabilizers for synthetic elastomers
Inventors:
Siegfried Rosenberg, Kurt Schwarzenbach
Patented Case
View Patent ↗
Granted: Dec 26, 1989
Filed: May 4, 1987
Inventors
Siegfried Rosenberg
Kurt Schwarzenbach
Assignee (at issue)
Ciba-Geigy
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.