Method for preparing liquidized butyl diphenylamine/octyl diphenylamine

Abstract

The invention relates to a method for preparing liquidized butyl diphenylamine / octyl diphenylamine. The method comprises the following steps: mixing diphenylamine with C8 alkene according to a mole ratio of 1:1.35-1:3.2, adding 5 to 25% of catalyst and polymerization inhibitor, carrying out alkylation reactions for 0.5 to 20 hours at a temperature of 80 to 165 DEG C under a reaction pressure of 0.25 to 0.5 MPa; wherein the addition amount of the polymerization inhibitor is 60 to 180 ppm; then adding ending alkene, wherein the adding amount of the ending alkene is 10 to 40% of the molar weight of the diphenylamine; heating the reaction product, filtering, then subjecting the filtrate to reduced pressure distillation, collecting the solid catalyst for cycle use, collecting and recovering the alkene, returning the collected alkene to the reaction system, and collecting the liquid namely the liquidized butyl diphenylamine / octyl diphenylamine. The color of obtained product is lightened, the product is clear and transparent, the base number reaches 140 to 180, the content of residual diphenylamine is less than 1%, the conversion of diphenylamine is increased, the performance of the product on controlling the viscosity increasing is excellent, the catalyst can be repeatedly used, and no wastewater is discharged.

Description

technical field [0001] The invention relates to a preparation method of butyl and octyl diphenylamine involving active olefins. Background technique [0002] Butyl and octylated diphenylamine antioxidants have excellent oxidation resistance, high thermal stability, good oil solubility, ash-free and phosphorus-free, etc., according to olefin isomerization, reaction conditions, and preparation processes. , There are two products of solidified and liquefied diphenylamine. The solidified product has stronger oxidation resistance, but the liquefied alkyl diphenylamine has better oil solubility and is easier to deploy, so it is more widely used in lubricating oil. [0003] The conventional preparation method of butyl and octylated diphenylamine is as follows: using diphenylamine as raw material, under the catalysis of Lewis acid or protonic acid catalyst, the initial product is obtained by alkylation reaction with C8 olefin, and then obtained through a series of post-reaction trea...

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Problems solved by technology

[0015] CN1288000A discloses a method for preparing liquefied alkylated diphenylamine, which comprises contacting and reacting diisobutylene with diphenylamine at 170°C to 230°C and a pressure of 0.2 to 0.5Mpa in the presence of an activated clay catalyst. Stop the reaction when the content of bis-octyldiphenylamine in the product is less than 20%, which solves the disadvantage of unstable temperature in the reaction process caused by the reflux of diisobutylene

[0017] CN1882651A discloses a method for preparing octylated diphenylamine, the antioxidant composition comprises 65%-98% by weight of dioctyl diphenylamine, up to 1.5% by weight of trioctyl diphenylamine, up to 1% by weight of diphenylamine, can Produced by alkylation of diisobutylene-p-diphenylamine in the presence of a catalyst, complicated recrystallization steps

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