PROCESS FOR PREPARATION OF QUINONE DIIMINE ANTIOXIDANT FOR SOLUTION RUBBERS Russian patent published in 2018 - IPC C07C209/18 C07C211/55 C07C249/02 C07C251/22 C08K5/29 C09K15/18 

FIELD: chemistry.

SUBSTANCE: invention relates to process for preparation of a quinone diimine antioxidant for solution rubbers. According to the method of invention, an alkylate, obtained in the process of alkylation of 4-aminodiphenylamine with 2-ethylhexanol in the presence of potassium hydroxide at a temperature of 190–235 °C with stripping of an azeotrope of alcohol with reaction water, containing N-2-ethylhexyl-N'-phenyl-p-phenylenediamine, a 10–19 % sodium hypochlorite solution in amount of from 0.10 to 0.20 mole per 1 mole of N-2-ethylhexyl-N'phenyl-p-phenylenediamine contained in the alkylate. Wherein temperature of about 25 °C is maintained. After completion of dosing of sodium hypochlorite, the resulting reaction mass is washed by addition of water, mixed, sedimented, the aqueous layer is separated from the organic layer, operation of washing and separating the aqueous layer from the organic layer is repeated twice, after which the desired product is isolated from the organic layer. Desired product is a liquid mixture of N-2-ethylhexyl-N'-phenyl-p-quinone diimine and starting N-2-ethylhexyl-N'-phenyl-p-phenylenediamine with a mole ratio of these compounds from 10:90 to 20:80. Invention also relates to process for preparation of a quinone diimine antioxidant in which a hydrogen peroxide solution is used instead of a sodium hypochlorite solution, as well as to the quinone diimine antioxidant for the solution rubbers obtained by said methods.

EFFECT: proposed methods allow to obtain a quinone diimine antioxidant that can be used to fill polymer solutions of solution rubbers and excludes leaching and evaporation of the antioxidant upon their isolation.

3 cl, 6 ex