Patent ID: 7718722

Claim:
A composition comprising an alkylthio-, arylthio-, or heteroylthio-substituted p-phenylenediamine compound having the formula: where: X and Y each comprise NHR where R is one selected from the group of alkyl, cycloalkyl, or aryl when X and Y are the same, and R is one selected from the group of hydrogen, alkyl, cycloalkyl, or aryl when X and Y are different; and R′ is one selected from the group of alkyl, cycloalkyl, aryl, 2-chlorobenzyl, 2-carboxyphenyl, benzyl, mercaptoethyl ether, alkyl 3-propionate, and a heterocyclic moiety, wherein the heterocyclic moiety is one selected from the group consisting of: 2-pyrazines, 3-pyrimidines, 2-pyridines, 3-pyridines, 4-pyridines, 2-pyrimidines, 2-(4,6-dimethyl)pyrimidines, 1,3,5-triazinyl, 2,6-pyridyl, 2,5-thiadiazolyl, 2-toluimidazole, 3-hydroxy-2-mercaptopyridine, and triazenes; wherein when R′ is alkyl, then R is cycloalkyl or aryl for at least one of X or Y; wherein when X is NH 2 and Y is NHR with R being aryl, and R′ is alkyl, then R′ is a C 2 -C 18 alkyl.