AMINE ANTIOXIDANTS FOR LUBRICATING OIL AND MOTOR FUEL AND PRODUCTION METHODS THEREOF Russian patent published in 2012 - IPC C07C211/51 C07C209/16 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing N-n-octyl-N'-phenyl-p-phenylenediamine and N-2-ethylhexyl-N'-phenyl-p-phenylenediamine. The method is realised through alkylation of p-aminodiphenylamine with potassium alcoholate solution in p-octyl (or 2-ethylhexyl) alcohol in uniform portions added to hot molten p-aminodiphenylamine. Alcohol azeotrope is then distilled with water. An organic layer is then separated after aqueous extraction of the reaction mass and N-n-octyl-N'-phenyl-p-phenylenediamine or N-2-ethylhexyl-N'-phenyl-p-phenylenediamine is then extracted therefrom. Alkylation is carried out with half of the prepared amount of potassium alcoholate solution by adding in a single step to the molten p-aminodiphenylamine which is heated to 140-150°C. Temperature in the reactor is then raised to 209°C and the remaining amount of the potassium alcoholate solution is fed. Feeding is carried out until 90% conversion of p-aminodiphenylamine, after which the reaction mass is heated to 232-235°C while blowing with a nitrogen current. The invention also relates to a method of producing N-2-ethylhexyl-N'-phenyl-p-phenylenediamine through vacuum distillation at cut vapour temperature of 240±5°C.

EFFECT: reduced increase in viscosity, acid number and formation of sludge of lubricating and/or motor fuel subjected to thermal oxidation.

2 cl, 6 tbl, 13 ex