Method for synthesizing sulfur-containing bisphenol compound antioxidant

Abstract

The invention discloses a method for synthesizing a sulfur-containing bisphenol compound antioxidant and belongs to the technical field of antioxidants. The method comprises the steps as follows: adopting 55-65% of ethanol water solution as a reaction solvent and 2,6-di-tert-butylphenol, paraformaldehyde and sodium hydrosulfide as reaction raw materials, adding a crystallization nucleating agent, carrying out thio-condensation reaction in a closed reaction kettle, and preparing a methylene-4426-S product as the antioxidant. A reaction mother solution obtained after reaction can be recycled as a reaction solvent. The crystallization nucleating agent has the effect of a phase-transfer catalyst, which is favorable for reaction of oil-soluble materials and water-soluble materials and increment of the yield. The method has the characteristics of simple production process, high product yield, low production cost, good quality and convenience for industrial production.

Description

technical field [0001] The invention relates to a technical method for optimizing and synthesizing a sulfur-containing bisphenol compound antioxidant product, and belongs to the technical field of antioxidants. Background technique [0002] Methylidene-4426-S is a sulfur-containing bisphenol compound antioxidant product, mainly used for synthetic rubber, polyolefin plastics and other polymer materials, as well as lubricants, fuel oil and other oil products. Sulfur-containing bisphenol Compound antioxidant products specifically refer to the following formula (I): [0003] [0004] (I) [0005] (I) Chemical name: bis(3,5-di-tert-butyl-4-hydroxybenzyl) sulfide, (referred to as methylene-4426-S). [0006] The method of synthesizing methylene-4426-S products in the past technology uses 2,6-tert-butylphenol (referred to as 2,6-phenol), 36% formaldehyde aqueous solution, and sodium sulfide as raw materials, and carries out thiocondensation reaction in ethanol aqueous solution...

AI Technical Summary

Problems solved by technology

Its weak point is: when 80~85% high-concentration ethanol aqueous solution is reaction solvent, the solubility of reaction mother liquor to methylene-4426-S product is bigger, carries out solid-liquid separation under normal temperature, and some products dissolve in reaction solution In this process, the reaction solution needs to be cooled to 3~6°C through a freezing process to effectively crystallize the product from the reaction solution and then separate it; in addition, the technology of CN102617424A is to complete the methylene-4426-S product in the synthesis reactor At the same time, the recrystallization process of the methylene-4426-S product in 80-85% high-concentration ethanol aqueous solution is completed. Therefore, the amount of solvent used in the process parameters of the design raw material ratio is relatively large. The usual solvent The amount of addition is 2,6-phenol: 80~85% ethanol aqueous solution (mass ratio) = 1:8.0~10.0, due to the increase in the amount of reaction solvent, the circulation of the recovered solvent increases, and the energy consumption increases; the volume of the same reactor produces Decreased capacity and reduced reactor utilization

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