CN112427049A

CN112427049A - Catalyst for producing vulcanization accelerator TBBS by heterogeneous oxygen method and application method thereof

Info

Publication number: CN112427049A
Application number: CN202011508413.2A
Authority: CN
Inventors: 回俊博; 孟庆森; 莫世军
Original assignee: Kemai Chemical Co Ltd
Current assignee: Kemai Chemical Co Ltd
Priority date: 2020-12-18
Filing date: 2020-12-18
Publication date: 2021-03-02
Anticipated expiration: 2040-12-18
Also published as: CN112427049B

Abstract

The invention belongs to the field of chemical combination and physical methods, and particularly relates to a catalyst for producing a vulcanization accelerator TBBS by a heterogeneous oxygen method and an application method thereof, wherein the catalyst is prepared by the following method: mixing and stirring a metal salt solution and resin, standing, filtering, washing and drying the resin to obtain an adsorption catalyst; wherein, the resin is ion exchange resin or chelating resin. The catalyst can form a chelating product with metal ions due to the chelating group contained in the resin, has strong adsorption effect on the metal ions, and can reduce the concentration of the catalyst in a reaction system to be far lower than 1 ppm. Compared with the traditional catalyst with autocatalytic decomposition, the catalyst activity is reduced due to coupling of two molecules, and the heterogeneous catalyst has stable catalytic effect and almost no reduction of activity after multiple application.

Description

Catalyst for producing vulcanization accelerator TBBS by heterogeneous oxygen method and application method thereof

Technical Field

The invention belongs to the field of chemical combination and physical methods, and particularly relates to a catalyst for producing a vulcanization accelerator TBBS by a heterogeneous oxygen method and an application method thereof.

Background

The rubber is used in producing various rubber products, such as tyre, rubber pipe, rubber shoe, etc. it has the advantages of short vulcanization time, low vulcanization temperature, less vulcanizing agent consumption, high mechanical performance, etc.

The accelerator TBBS (the Chinese name of N-tertiary butyl-2-benzothiazolyl sulfenamide) is a post-effect accelerator of NR, BR, IR, SBR and mixed rubber thereof, and is particularly suitable for carbon black rubber materials with stronger alkali property. TBBS has the advantages of low toxicity, high efficiency, safety at operating temperature, strong scorch resistance, high vulcanization speed, high stress at definite elongation and the like, is an ideal substitute of NOBS, is called as a standard accelerator, and is particularly suitable for radial tires. Therefore, with the improvement of the tire yield and the tire meridional ratio, the amounts of the accelerators DCBS, TBBS and DDCBS have been greatly increased in recent years. According to the statistics of the Chinese rubber industry society, the total yield of the accelerators in 2014 in China is 37.5 ten thousand tons, wherein the slow-acting sulfenamide accelerators represented by TBBS, DCBS and DDCBS account for 42.51 percent of the yield of the accelerators.

The current industrialization method of the rubber vulcanization accelerator TBBS is to oxidize an accelerator MBT or sodium salt thereof in the presence of tert-butylamine by using sodium hypochlorite as an oxidant to generate the accelerator TBBS. The sodium hypochlorite method has the advantages of mature process, mild reaction conditions, good product quality and high yield (generally about 90-92%). However, the amount of wastewater produced is large (about 8 tons of wastewater are produced in 1 ton of products), and the salt content is high, so that the biochemical treatment is difficult.

As an improvement of the sodium hypochlorite process, the hydrogen peroxide-sodium hypochlorite process is also used in research and production practices. The hydrogen peroxide-sodium hypochlorite method replaces part of sodium hypochlorite with hydrogen peroxide to partially oxidize MBT or MBT sodium salt. Thereafter, sodium hypochlorite is added for final oxidation. Compared with the sodium hypochlorite method, the hydrogen peroxide-sodium hypochlorite method reduces the generation of waste salt, but still has more waste water.

As a new accelerator production method, the oxygen method has attracted much attention because of its low wastewater generation and low salt content. The oxygen method generally uses cobalt phthalocyanine as a catalyst to form TBBS under tert-butylamine and a certain oxygen pressure and temperature. The amount of wastewater of the oxygen method is only 1/8 or less compared to the sodium hypochlorite method. As no acid or alkali is added, the wastewater does not contain inorganic salts, and only part of MBT is excessively oxidized to form benzothiazole sulfonate. Meanwhile, the oxygen method can achieve the similar yield (90-92%) of the sodium hypochlorite method. However, the oxygen method has the main problems that the synthesis cost of the catalyst is high and the catalyst is inactivated in the using process. Meanwhile, the catalysts are homogeneous catalysts, and are difficult to recover and recycle after reaction.

In conclusion, the traditional production process of TBBS by the sodium hypochlorite method has the defects of more wastewater, high salt content and the like, and is currently faced with more environmental and water treatment risks; the oxygen method is not mature, and the homogeneous catalyst has the defects of easy inactivation, difficult recycling and the like.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provides a catalyst for producing a vulcanization accelerator TBBS by a heterogeneous oxygen method and an application method thereof.

In order to achieve the purpose, the invention adopts the technical scheme that:

a catalyst for producing a vulcanization accelerator TBBS by a heterogeneous oxygen method is prepared by the following steps: mixing and stirring a metal salt solution and resin, standing, filtering, washing and drying the resin to obtain an adsorption catalyst;

the resin is chelating resin; the chelating resin has aminocarboxylic acid.

Preferably, the resin is styrene-amine carboxyl resin 401X 7.

Preferably, the metal salts include soluble chlorides, sulfates and nitrates of copper, iron, cobalt, nickel, platinum, gold or palladium. Preferably, the metal salt is cobalt chloride.

Preferably, the mass volume ratio of the metal salt to the resin is 1: 10-25.

The invention also comprises an application method of the catalyst, which comprises the following steps:

(1) adding an accelerator MBT, tert-butylamine, water, an organic solvent and a catalyst for producing a vulcanization accelerator TBBS by the heterogeneous oxygen method into a reaction kettle, and introducing oxygen for reaction;

(2) discharging the reacted materials after the reaction is finished, filtering, separating the catalyst for producing the vulcanization accelerator TBBS by a heterogeneous oxygen method, separating liquid phase, taking an organic phase as an upper layer, cooling and crystallizing to obtain a TBBS crude product, washing the TBBS crude product obtained by filtering with water to obtain a TBBS wet material, and drying to obtain a TBBS finished product.

Preferably, the method further comprises the following steps: and (3) mixing the mother liquor crystallized in the upper layer in the step (2) with the lower layer liquid after liquid separation, and supplementing MBT and tert-butylamine for cyclic application.

The mass ratio of the MBT to the tert-butylamine to the water to the organic solvent is 1: 4-6: 3-5: 3-5; the reaction temperature is 40-60 ℃; the reaction time is 1-2 h.

Compared with the prior art, the invention has the beneficial effects that:

the catalyst can form a chelating product with metal ions due to the chelating group contained in the resin, has strong adsorption effect on the metal ions, and can reduce the concentration of the catalyst in a reaction system to be far lower than 1 ppm. Compared with the traditional catalyst with autocatalytic decomposition, the catalyst activity is reduced due to coupling of two molecules, and the heterogeneous catalyst has stable catalytic effect and almost no reduction of activity after multiple application.

The catalyst is applied to synthesis of TBBS, and is easy to separate compared with a traditional homogeneous catalyst because the catalyst is heterogeneous. Conventional homogeneous catalysts; for example, cobalt phthalocyanine or cuprammonium, the catalyst is easy to be entrained in the solution, and the color of the product is influenced, meanwhile, metal ions in the homogeneous catalyst exist in the mother liquor, and the metal ions in the wastewater need to be post-treated; the catalysts of the present application do not have this problem due to the strong chelation.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the following provides a detailed description of the present invention with reference to the embodiments.

Example 1: preparation of the catalyst: the method specifically comprises the following steps: (1) the metal salt is dissolved in water and then the resin is added. Stirring and standing. Then filtering, washing twice with water, and drying to obtain a resin catalyst; the catalysts obtained in the different examples are shown in table 1.

TABLE 1

The catalysts obtained in examples 1 to 9 were used in the preparation of TBBS, and the specific reaction conditions are shown in table 2:

TABLE 2

As can be seen from the data of the examples, the amine carboxylic acid has the best catalytic effect among various resins, and the catalyst formed by the amine carboxylic acid and various metals has certain catalytic effect. Of all the amine carboxylic acid resin-metal catalysts, cobalt activity was best and the product was also in the highest yield. Even after 10 reuses, the yield of product TBBS was over 90%, indicating a very high stability of the catalyst.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. The catalyst for producing the vulcanization accelerator TBBS by the heterogeneous oxygen method is characterized by being prepared by the following method: mixing and stirring a metal salt solution and resin, standing, filtering, washing and drying the resin to obtain an adsorption catalyst; wherein the resin is a chelating resin; the chelating resin has aminocarboxylic acid.

2. The catalyst for producing the vulcanization accelerator TBBS according to claim 1, wherein the chelating resin is a styrene-amino carboxylic acid resin 401X 7.

3. The catalyst for producing the vulcanization accelerator TBBS according to claim 1, wherein the metal salt comprises a soluble hydrochloride, sulfate or nitrate salt of copper, iron, cobalt, nickel, platinum, gold or palladium.

4. The catalyst for producing the vulcanization accelerator TBBS according to any one of claims 1 to 3, wherein the mass-to-volume ratio of the metal salt to the resin is 1: 10-25.

5. A method of using the catalyst of any one of claims 1 to 4, comprising the steps of:

6. The method for using the catalyst according to claim 5, further comprising the steps of:

and (3) mixing the mother liquor crystallized in the upper layer in the step (2) with the lower layer liquid after liquid separation, and supplementing MBT and tert-butylamine for cyclic application.

7. The method for using the catalyst according to claim 5, wherein the feed mass ratio of MBT, tert-butylamine, water and organic solvent is 1: 4-6: 3-5: 3-5; the reaction temperature is 40-60 ℃; the reaction time is 1-2 h.