Preparation method of alkylated diphenylamine antioxidant product

Abstract

The invention discloses a preparation method of an alkylated diphenylamine antioxidant product, belonging to the technical field of synthetic materials and lubricating oil. The preparation method comprises the following steps of: proportionally adding an FS-2 catalyst, diphenylamine, a polymerization inhibitor and an organic solvent into a synthesis reaction kettle, wherein the ratio of the diphenylamine to alpha-vinyltoluene is 1:(2.1-2.5); the ratio of the diphenylamine to the FS-2 catalyst is 1:(0.1-0.18); the ratio of the diphenylamine to the polymerization inhibitor is 1:(0.003-0.008); and the ratio of the diphenylamine to the organic solvent is 1:(1.0-1.5); dropwise adding alpha-vinyltoluene under good nitrogen protection at a reaction temperature, preserving heat, and reacting to obtain an alkylated diphenylamine mixed solution; and filtering and separating the catalyst, recrystallizing a filtrate, filtering, washing and drying to obtain an antioxidant product. The effects of the FS-2 catalyst and the polymerization inhibitor are further proved through a contrast experiment.

Description

technical field [0001] The invention belongs to the technical field of synthetic materials and lubricating oil, and relates to a preparation method of an alkylated diphenylamine antioxidant product, in particular to 4,4-bis(α,α-dimethylbenzyl)diphenylamine (DW for short) -DPA) the preparation method of antioxidant product, the chemical structural formula of DW-DPA is as follows: [0002] . Background technique [0003] As an antioxidant, diphenylamine has the disadvantages of being easy to volatilize and having poor resistance to oxygen, which is generally improved by adding a group with a large relative molecular weight. It was found that the alkylation reaction between diphenylamine and the corresponding active olefin can obtain a non-polluting antioxidant with good antioxidant properties. For example, diphenylamine undergoes alkylation reaction with styrene, α-methylstyrene, nonene, dimer isobutylene, etc. to generate corresponding alkylated diphenylamine compounds, t...

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Problems solved by technology

[0004] US: 2943112 discloses that sulfuric acid and activated clay are used as catalysts to carry out catalytic reaction of dimerized isobutylene and diphenylamine to prepare octylated diphenylamine mixtures. The activity and selectivity of the catalyst are low. At 180-190°C, the molar ratio of dipolyisobutylene to diphenylamine is 1:4, and the catalyst containing about 10% activated clay and 0.3% concentrated sulfuric acid is reacted for 4-5h. The result 6-12% of unreacted diphenylamine exists in the product, so that the finally obtained liquid octylated diphenylamine mixture antioxidant product has sludge deposits, and the presence of diphenylamine reduces the antioxidant performance of the product, giving The high toxicity of the product, the pollution of the polymer and other adverse factors, in addition, the free inorganic acid is used as the catalyst, and there is sewage in the production process

[0005] US: 3496230 discloses the use of AlCl 3 As a catalyst, nonene and diphenylamine are catalyzed to prepare a mixture of nonylated diphenylamines. This invention embodies the AlCl 3 High activity and high selectivity of the catalyst, containing about 8% AlCl at 120-130°C 3 The catalyst is reacted for 6h to obtain 80% dinonylated diphenylamine and 15% monononylated diphenylamine. 3 A large amount of sewage will be generated during the catalyst process

[0006] US: 4263456 discloses that activated clay is used as a catalyst, and styrene and diphenylamine are catalyzed to react to prepare a styrenated diphenylamine mixture. The reaction is carried out at 204°C with about 10% of the catalyst, and the result is that the product contains 0.5% unreacted 4.4% ortho monostyrenated diphenylamine; 7.5% para monostyrenated diphenylamine; 9.4% ortho-ortho distyrenated diphenylamine; 11.7% para-ortho 37.4% p-position-para-position di-styrenated diphenylamine, 27.0% p-position-ortho-para-position tristyrenated diphenylamine, the disadvantage is that the reaction temperature is higher, It is easy to cause carbon deposition on the catalyst; the content of tristyrenated diphenylamine is high, and the selectivity of para-para bistyrenated diphenylamine is low

At 220°C, containing about 6% catalyst, styrene and diphenylamine are catalyzed to react to prepare a styrenated diphenylamine mixture. The disadvantage is that the reaction temperature is relatively high, and the catalyst is easy to deposit carbon.

[0008] CN: 101353445A discloses that activated clay is used as a catalyst, and styrene and diphenylamine are catalyzed to react to prepare a styrenated diphenylamine mixture. 10% of the catalyst was reacted for 4 hours to obtain a styrenated diphenylamine mixture product. The disadvantage is that the reaction temperature is relatively high, and the catalyst is prone to carbon deposition