Preparation technique for polymerization inhibitor products

Abstract

The invention relates to a technique for preparing a polymerization inhibitor product. The polymerization inhibitor product is a mixed solution consisting of para-tertiary butyl pyrocatechol and aliphatic hydrocarbon solvent. The synthesis technique for the para-tertiary butyl pyrocatechol comprises the following steps: using pyrocatechol and isobutene as raw materials, using LCS-7 or LANK-98 or FS-1 solid acid as a catalyst for alkylation reaction, and carrying out catalytic alkylation reaction in a closed reaction kettle; and after the reaction is finished, filtering and rectifying the catalyst in the alkylation solution to separate out pyrocatechol as the raw material and by-product to obtain the para-tertiary butyl pyrocatechol. The para-tertiary butyl pyrocatechol is dissolved in the aliphatic hydrocarbon solvent, to prepare even mixed solution, so as to obtain the polymerization inhibitor product. The technique has the characteristics of simple production process, high product yield, low production cost, good quality and basically no environmental pollution, and is convenient for industrialized production.

Description

technical field [0001] The invention relates to a preparation process method of a polymerization inhibitor product, which specifically refers to a mixed solution composed of the substance of the following formula (I) and an aliphatic hydrocarbon solvent. Chemical name of the substance of formula (I): 4-tert-butyl-2-hydroxy-phenol, (abbreviation: p-tert-butylcatechol or TBC). [0002] The method for synthesizing p-tert-butyl catechol takes catechol and isobutylene as raw materials, adopts solid acid as an alkylation catalyst, and conducts catalytic alkylation in a closed reactor. [0003] [0004] (I) [0005] Aliphatic hydrocarbon solvents are benzene, toluene, xylene, C 6 ~C 9 Straight or branched chain alkanes. Background technique [0006] P-tert-butylcatechol is an efficient polymerization inhibitor for olefin monomer distillation or storage and transportation, it is a colorless crystalline substance, melting point: 53.0-57.0℃. Soluble in methanol, carbon tetrach...

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Problems solved by technology

[0024] Although this technological method has obtained the conversion rate of higher pyrocatechol and the yield of product, because the charging amount of catalytic active clay is more than 30% of pyrocatechol, a large amount of waste residues are generated in the production process; In addition, Catechol: isobutene (molar ratio) 1:2.4—2.6, excess isobutene and activated clay are easy to self-polymerize under high reaction pressure and temperature to form isobutylene dimers, trimers and polymers, etc. By-products make the unit consumption of isobutene raw materials higher; in addition, the reaction raw materials catechol and excess isobutene are added to the reactor at one time, and the self-contained pressure at the reaction temperature is as high as 1.6MPa. Equipment requirements and unsafe factors increase, the concentration of reaction raw materials in the kettle is relatively high, the initial reaction rate is very large, and the instantaneous reaction heat release is large, so it is difficult to discharge the reaction heat out of the kettle in time in industrial production; what is more unfavorable is the Isobutylene polymers and 3-TBC, the boiling point of some polymers and 3-TBC is very close to TBC products, and they are in the same fraction as the products during the rectification separation process, so that the mass fraction of the products obtained in this way is less than 95%, and the melting point If the temperature is less than 42°C, the petroleum ether recrystallization and refining process is required to ensure that the product meets the industrial-grade quality standard TBC product

In view of the above reasons, this process method is not satisfactory, nor is it convenient to carry out industrialized production

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