RU2415124C2 - Method of producing 2,2-methylene-bis-(4-methyl-6-tertbutylphenol) - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing 2,2-methylene-bis-(4-methyl-6-tertbutylphenol), which is a high-efficiency, low-volatile, non-colouring, non-toxic and non-discolouring antioxidant used for stabilising rubber, unvulcanised rubber, petroleum products, plastic, fibre and paint products. The method involves re-alkylation of a mixture of 2,6-di-tert-butyl-4-methylphenol and paracresol in the presence of an acid catalyst at high temperature, neutralisation of the obtained alkylate, extraction of 2-tertbutyl-paracresol through fractionation and condensation thereof with formaldehyde, and then washing the obtained product. Condensation is carried out in the presence of a hydrocarbon solvent and alkyl-benzene sulphonic acid as a catalyst-surfactant. Further, a second portion of hydrocarbon solvent is added. Crystallisation is carried out at low temperature. Filtration is carried out, followed by washing the obtained product, high-temperature processing of the filtrate water, separation of the organic phase of the filtrate water, regeneration of the hydrocarbon solvent therefrom and returning it into the process.

EFFECT: method enables to obtain an end product with improved quality while increasing utilisation of raw material and auxiliary materials.

2 cl, 1 tbl, 5 ex

Description

The invention relates to the petrochemical industry, specifically to a method for producing 2,2-methylene-bis- (4-methyl-6-tert-butylphenol), a highly effective non-staining non-staining, non-toxic and non-bleaching antioxidant used to stabilize rubbers, rubbers, latexes, petroleum products, plastics, fibers, paint and varnish products, etc.

A known method of producing 2,2-methylene-bis- (4-methyl-6-tert-butylphenol) by condensation of formaldehyde with 2-tert-butyl-paracresol in the presence of concentrated hydrochloric acid as a catalyst, followed by the addition of heptane, neutralization of the reaction mass with soda or alkali and filtering the precipitate (US Patent No. 2538355, publ. 16.01.1951).

The disadvantage of this method is the low yield of the target product - 77% of theoretical, the complexity of the separation of the catalyst.

A known method for producing 2,2-methylene-bis- (4-methyl-6-tert-butylphenol) comprising dealkylation of 2,6-di-tert-butyl-4-methylphenol by heating on an arylsulfonic acid catalyst, followed by condensation of the reaction mixture with methylal in the presence of N , N-di-methyl- (3,5-di-tert-butyl-4-hydroxybenzyl) -amine (Mannich base) with a molar ratio of arylsulfonic acid: Mannich base 1.00: 0.01-0.5 (RF Patent No. 2150461, С07С 39/16, С07С 37/20, publ. 10.06.2000).

The disadvantages of the method are low selectivity, low yield and, accordingly, high consumption rates of 2,6-di-tert-butyl-4-methylphenol.

Closest to the proposed invention is a method for producing 2,2-methylene-bis- (4-methyl-6-tert-butylphenol) by alkylation of a mixture of 2,6-di-tert-butyl-4-methylphenol and paracresol in a molar ratio of 1: (1, 3-3) in the presence of an acidic catalyst at 55-85 ° C. After neutralization of the alkylate, the isolation of monoalkylparacresol is carried out by rectification, crystallization and condensation of monoalkylparacresol with formaldehyde in the presence of a hydrocarbon solvent, a surfactant and an acid catalyst. The resulting product is filtered, washed and dried (RF Patent No. 2049087, C07C 39/16, C07C 37/48, publ. 11/27/1995).

The disadvantages of this method include the low quality of the target product obtained (in the practical implementation of the method, a product with a melting point of 126-128 ° C containing at least 3% impurities is obtained) and high consumption rates of the hydrocarbon solvent are about 150 kg per 1 ton 2.2 -methylene-bis- (4-methyl-6-tert-butylphenol).

The task of the invention is to improve the quality of 2,2-methylene-bis- (4-methyl-6-tert-butylphenol) and increase the degree of use of raw materials and auxiliary materials.

The problem is solved by implementing a method for producing 2,2-methylene-bis- (4-methyl-6-tert-butylphenol), including transalkylation of a mixture of 2,6-di-tert-butyl-4-methylphenol and paracresol in the presence of an acid catalyst at elevated temperature neutralization of the obtained alkylate, isolation of 2-tert-butyl-paracresol by distillation and its condensation with formaldehyde in the presence of a hydrocarbon solvent and alkyl-benzenesulfonic acid as a surfactant-catalyst, adding a second portion of carbohydrates hydrogen solvent, crystallization at a low temperature, filtration followed by washing of the obtained product, high-temperature treatment of the centrate, separation of the organic phase of the centrate, regeneration of the hydrocarbon solvent from it, its return to the process and disposal of the bottom product of the organic phase of the centrate, which can be used to obtain antioxidant additives to motor gasolines or to obtain a stabilizer with the same field of application as 2,2-methylene-bis- (4-methyl-6-tre butylphenol).

The addition of a second portion of the hydrocarbon solvent after the condensation stage and crystallization from it allows almost completely dissolving the impurities resulting from the condensation and obtain 2,2-methylene-bis- (4-methyl-6-tert-butylphenol) of the required quality, containing at least 99 9% of the basic substance.

The addition of the stages of heat treatment of the centrate to the technological process, the regeneration of the hydrocarbon solvent from its organic part, the return of the solvent to the technological process and the utilization of the bottom product of the organic phase of the centrate allows increasing the degree of use of auxiliary materials (the consumption rate for the hydrocarbon solvent is reduced by 15-30 times in comparison with the prototype up to 5-10 kg per 1 ton of 2,2-methylene-bis- (4-methyl-6-tert-butylphenol) and the main raw materials, since the bottom product of the organic part of the centrate, containing s to 70% of the desired product - 2,2-methylene-bis- (4-methyl-6-tert-butylphenol) may be used to produce antioxidant additives to automobile gasolines or stabilizer to obtain the same field of application as the target product.

It is preferable to use as a catalyst the transalkylation reaction of macroporous sulfocationite.

The preferred temperature ranges for the reaction of the alkylation of 2,6-di-tert-butyl-4-methylphenol and paracresol are 80-120 ° C, the condensation of 2-tert-butyl paracresol with formaldehyde is 60-80 ° C, and crystallization is 20-40 ° C .

VAT product of the organic part of the centrate mainly contains 70% wt. 2,2-methylene-bis- (4-methyl-6-tert-butylphenol), 20% trisphenols, the rest are unidentified alkyl phenols. Such a composition meets the requirements for raw materials for obtaining an antioxidant additive to motor gasolines, for example, known as Agidol-12 or to obtain a stabilizer with the same field of application as 2,2-methylene bis- (4-methyl-6- tert-butylphenol).

The method according to the invention is illustrated by the following examples.

Example 1

320 g of 2,6-di-tert-butyl-4-methylphenol, 160 g of paracresol and 20 g of KSM cation exchanger are loaded into a three-necked flask equipped with a stirrer and reflux condenser. With constant stirring and a temperature of 110 ° C maintain the contents for 10 hours.

Upon completion of the transalkylation reaction, the reaction mass is separated from the catalyst, 1 g of soda ash is added. Neutralization is carried out at a temperature of 110 ° C for 2 hours, filtering is carried out and 445 g of transalkylate are fed for rectification.

Example 2

Received in an amount of 445 g of neutral transalkylate according to example 1 in order to isolate the target fraction of 2-tert-butyl-paracresol is subjected to rectification. Get 2-tert-butyl-paracresol - rectified 307.54 g

The material balance of rectification is presented in the table.

Table Stream name Starting alkylate Lungs Paracresol - Return 2 -tertbutyl-paracresol VAT product Losses g % wt. g % wt. g % wt. g % wt. g % wt. g No. one 2 3 four 5 6 Lungs 0.08 0.02 0.08 1.94 Paracresol 33.63 7.56 1.18 29.42 24.15 62.48 0,03 0.01 2-tert-butyl paracresol 344.21 77.35 2,52 63.06 14.5 37.52 307.51 99,99 3.25 4.86 2,6-di-tert-butyl-4-methylphenol 64,43 14.48 0.22 5.58 60.93 91.17 Heavy impurities 2.65 0.59 2.65 3.97 Total 445 one hundred four one hundred 38.65 one hundred 307.54 one hundred 66.83 one hundred 27.98

Example 3

Conduct the condensation of 2-tert-butyl-paracresol obtained in example 2, with formaldehyde in a flask with a stirrer, and a reflux condenser and a dropping funnel.

307.54 g of 2-tert-butyl-paracresol, 615.0 ml of water, 31 g of gasoline, 3.1 g of alkylbenzenesulfonic acid acting as a surfactant-catalyst are loaded into the flask. Stirred at 60 ° C until an emulsion is formed. Raise the temperature to 90 ° C and dose formalin with a formaldehyde content of 36-38%. Upon completion of the reaction, cool the reaction mass to 60 ° C, neutralize with the calculated amount of soda, add 154 g of gasoline and cool slowly to 30 ° C. The product is filtered off on a filter, washed and dried under vacuum at 80-90 ° C for 10 hours.

After drying, the product is obtained in an amount of 287 g with a melting point of 129-131 ° C (impurity content of less than 0.04% wt.).

The filtrate obtained after filtration is heated in an ampoule to 140-150 ° C until the emulsion is destroyed (0.5-2 hours), cooled to 30 ° C, the ampoule is opened, and the organic phase is separated.

Gasoline is distilled off from the organic phase. Get 182.5 g of gasoline and 16 g of VAT product containing 70% wt. 2,2-methylene-bis- (4-methyl-6-tert-butylphenol), 20% trisphenols, the rest are unidentified alkyl phenols. Such a composition meets the requirements for raw materials for obtaining an antioxidant additive to motor gasolines, for example, known as Agidol-12 or to obtain a stabilizer with the same field of application as 2,2-methylene bis- (4-methyl-6- tert-butylphenol).

Example 4

The condensation is carried out according to example 3 with the addition of octane in an amount of 31 g, after neutralization, add another 205 g of octane and slowly cooled to 20 ° C. The product is filtered off, washed and dried under vacuum at 80-90 ° C for 10 hours.

After drying, 283 g of 2,2-methylene-bis- (4-methyl-6-tert-butylphenol) with a melting point of 130-132 ° C (impurity content less than 0.03%) are obtained.

The centrate is treated as in example 3, to obtain a bottoms product weighing 22.5 g and octane distillate weighing 233 g

Example 5

The condensation is carried out according to example 3, after neutralization add 82 g of gasoline and slowly cool to 40 ° C.

Obtain 282 g of 2,2-methylene-bis- (4-methyl-6-tert-butylphenol) with a melting point of 128.5-130 ° C (impurity content of 0.06%).

After processing the centrate, a bottoms product weighing 14 g and 111.5 g of gasoline distillate is obtained.

As can be seen from the above examples, the production of 2,2-methylene-bis- (4-methyl-6-tert-butylphenol) by implementing a method comprising transalkylation of a mixture of 2,6-di-tert-butyl-4-methylphenol and paracresol in the presence of an acidic catalyst at elevated temperature, neutralization of the obtained alkylate, isolation of 2-tert-butyl-paracresol by distillation and its condensation with formaldehyde in the presence of a hydrocarbon solvent and alkyl benzenesulfonic acid as a surfactant-catalyst, adding a second portion of hydrocarbon solvent, crystallization at a reduced temperature, filtration with subsequent washing of the obtained product, high-temperature treatment of the centrate, separation of the organic phase of the centrate, regeneration of the hydrocarbon solvent from it, its return to the process and disposal of the bottom product of the organic phase of the centrate allows us to solve the problem, namely, improve the quality of 2,2-methylene-bis- (4-methyl-6-tert-butylphenol) and increase the degree of use of raw materials and auxiliary materials.

Claims (2)

1. A method for producing 2,2-methylene-bis- (4-methyl-6-tert-butylphenol), comprising transalkylation of a mixture of 2,6-di-tert-butyl-4-methylphenol and paracresol in the presence of an acid catalyst at an elevated temperature, neutralizing the obtained alkylate, isolation of 2-tert-butyl-paracresol by distillation and its condensation with formaldehyde, followed by washing of the obtained product, characterized in that the condensation is carried out in the presence of a hydrocarbon solvent and alkyl benzenesulfonic acid as a surface-active substance - catalysis ora, then a second portion of the hydrocarbon solvent, the crystallization is carried out at low temperature, filtering, followed by washing the resulting product, a high-temperature processing of supernatant, separating the organic phase of supernatant, the regeneration therefrom of a hydrocarbon solvent and return it to the process. 2. The method according to claim 1, characterized in that as the catalyst for the transalkylation reaction, macroporous sulfocationionite is used.