Liquid antioxidant produced by alkylating diphenylamine with a molar excess of diisobutylene

Abstract

Process is described for the production of a liquid antioxidant composition by reaction of diphenylamine with diisobutylene comprising reacting diphenylamine with diisobutylene in a molar ratio of from 1:1.1 to 1:2.5 and in the presence of an acid activated earth catalyst, while ensuring that the concentration of diisobutylene remains substantially constant throughout the reaction period at a reaction temperature of at least 160.degree. C., the reaction being effected for such a period that the content of 4,4'-dioctyldiphenylamine in the reaction mass, excluding catalyst, is below 25% by weight; and removing catalyst and unreacted diisobutylene; the product of this process; and the use of this product as a stabilizer for organic material against oxidative degradation.

Dependencies are inferred from the claim text.