Production process of antioxidant 2,6-di-tert-butyl-4-methy phenol

Abstract

The production process of 2, 6-di-tert-butyl -4-methyl phenol includes the following steps: the first alkylation reaction of paracresol, isobutene and solid catalyst; leading the reaction product to the crystallizing kettle while leaving the catalyst for further use and lowering temperature slowly to separate out crystal; repeating the foregoing steps; washing the initial crystal with water solution of sodium hydroxide and separating oily matter from the washed alkali solution for reuse; recovering ethanol from the mother liquid in a rectifying tower for reuse and separating out inferior 2, 6-di-tert-butyl -4-methyl phenol product from the residue; drying the re-crystallized product and packing. The present invention has the advantages of no drained waste water, no environmental pollution, high product quality, etc.

Description

technical field [0001] The invention relates to a production process of antioxidant 2,6-di-tert-butyl-4-methylphenol. Background technique [0002] 2,6-di-tert-butyl-4-methylphenol (T501 for short) is an excellent antioxidant, widely used, and non-polluting antioxidant, which can be used as polyvinyl chloride, polyethylene, polypropylene, polypropylene Antioxidant of ester, polystyrene, ABS resin, butyl rubber and other rubber and latex, can effectively inhibit air oxidation, thermal degradation and copper damage, etc., has no pollution, no coloring, low melting point, easy mixing, Does not bloom, does not affect rubber vulcanization, suitable for white, light-colored products, foam products. Its production method is to mix p-cresol and isobutylene as raw materials, add sulfuric acid for chemical reaction, and generate 2,6-di-tert-butyl-4-methylphenol, then add soda ash and sulfuric acid for neutralization reaction, and generate sodium sulfate, Carbon dioxide and water are...

AI Technical Summary

Problems solved by technology

The problems that the above-mentioned technique exists are: 1, add sulfuric acid as catalyst when feeding intake, must neutralize with alkali, in order to prevent pipeline from clogging, alkaline water must be warmed up to 70-80 ℃ (one ton of water); (two tons of water each time) to ensure that the ash content is qualified

Therefore, it not only consumes heat energy, but also must discharge about 3 tons of sulfur-containing wastewater, which will pollute the environment after discharge.

2. Use ethanol aqueous solution to make the product secondary crystallization, waste ethanol, and at the same time, the product dissolved in ethanol cannot be recovered, resulting in a decrease in product yield

3. Products that have been subjected to high temperature for three times will inevitably be polluted by air oxidation, so the shelf life of the product will be affected and the validity period will be shortened

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