Preparation method of thioether sterically hindered phenol antioxidant

Abstract

The invention discloses a preparation method of a thioether sterically hindered phenol antioxidant, which comprises the following steps: a first stage: carrying out transesterification on 3-(3, 5-di-tert-butyl-4-hydroxyphenyl) methyl propionate and thiodiglycol under the action of a solid base catalyst; a second stage: removing by-product methanol under reduced pressure; and a third stage, alternately removing unreacted raw materials by nitrogen purging and pressure reduction, cooling, filtering, and collecting the solid base catalyst to obtain the target product. The synthesis process is simple, solvent crystallization purification, drying and other operations do not need to be conducted on a reaction mixture, and the product can be obtained through direct cooling; the production period is short, the later solvent waste liquid treatment is reduced, and the production cost is obviously reduced.

Description

technical field [0001] The invention relates to the technical field of antioxidants, in particular to a preparation method of a sulfide type hindered phenolic antioxidant. Background technique [0002] Lubricating oil is affected by light, oxygen, and heat during use, and oxidized and deteriorated to form ketones, aldehydes, organic acids, etc., causing corrosion of equipment lubrication parts; at the same time, the above-mentioned oxidized substances will further polymerize to form sludge, paint film, etc. Lubrication and heat dissipation of the equipment, and too much sludge can easily cause the piston ring to stick and block the oil circuit. In order to inhibit the oxidative deterioration of lubricating oil and prolong the service life of lubricating oil, it is necessary to add a certain amount of antioxidant. [0003] Currently, zinc dialkyldithiophosphate (ZDDP) is a commonly used antioxidant in lubricating oils. In recent years, in order to improve the thermal effici...

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Problems solved by technology

[0010] 1. The effective product conversion rate of patents US4085132 and US4228297 is low, and the requirements must be purified by solvents. When the reaction mixture is crystallized and separated, the separation effect is poor, and the product yield is only about 50%, which is difficult to realize industrial application

[0011] 2. Patent CN102050768A uses a tin compound as a catalyst. After the reaction, acetic acid needs to be added to destroy the catalyst, and then crystallized, filtered, and dried to obtain the product. The operation process is cumbersome, and the solvent needs to be recovered and processed. The production cost is high and it is not conducive to Environmental friendly

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