| abstract |
Compounds of the formula: <IMAGE> wherein R, R' and R2 are alkyl radicals having 1 to 20 carbon atoms, phenyl radicals which may be substituted by 1 or 2 alkyl groups having 1 to 8 carbon atoms, aralkyl radicals having 7 to 12 carbon atoms, or cycloalkyl radicals having 5 to 12 carbon atoms; and wherein R3 is hydrogen or an alkyl radical having from 1 to 4 carbon atoms. These compounds have utility as synergistic stabilizers with phenolic type antioxidants for the stabilization of organic materials such as natural and synthetic polymers, rubbers, lubricants and oils, etc. |