CN116874445A

CN116874445A - Method for preparing vulcanization accelerator standard substance

Info

Publication number: CN116874445A
Application number: CN202310860121.2A
Authority: CN
Inventors: 郑夫忠; 张东晓
Original assignee: Lianyungang Shengao Chemical Technology Co ltd; Sennics Co ltd
Current assignee: Lianyungang Shengao Chemical Technology Co ltd; Sennics Co ltd
Priority date: 2023-07-13
Filing date: 2023-07-13
Publication date: 2023-10-13

Abstract

The embodiment of the application provides a method for preparing a vulcanization accelerator standard. The method comprises a first reactant purification step, wherein the first reactant purification step comprises the steps of forming a first reactant alkaline solution, performing first adsorption treatment on the first reactant alkaline solution, adjusting the pH value of the solution subjected to the first adsorption treatment to 7.5-9, and obtaining a purified first reactant; a synthesis step comprising mixing and reacting the purified first reactant, second reactant, and catalyst to obtain a fresh-made sulfation promoter; and a product purification step, wherein the product extraction step comprises the steps of sequentially carrying out second adsorption treatment and recrystallization treatment on the fresh-made sulfation promoter. Compared with the prior art, the application has the following beneficial effects: the operation is simple, and the standard product of the vulcanization accelerator with the purity not lower than 99.6 percent can be obtained.

Description

Method for preparing vulcanization accelerator standard substance

Technical Field

The application relates to the technical field of industrial synthesis, in particular to a method for preparing a vulcanization accelerator standard.

Background

Vulcanization accelerators, such as N-tert-butyl-2-benzothiazole sulfenamide (TBBS) or N-cyclohexyl-2-benzothiazole sulfenamide (CBS), are amine organic matters, can increase the dosage of filler carbon black, can increase the vulcanization speed, control the temperature in the vulcanization process, have various excellent performances of scorch resistance, non-toxicity, environmental protection and the like, and are mainly used in natural rubber, butadiene rubber, styrene butadiene rubber and isoprene rubber.

The vulcanization accelerator is produced by the reaction of a sulfhydryl compound and an amino compound, but the product impurities in the prior art for preparing the vulcanization accelerator are more, the purity is low and the main impurities cannot be removed. In addition, the purity analysis of the vulcanization accelerator needs to be calibrated by a standard, but the purity of the commercially available standard is low and is up to 98.5%, so that the purity measurement of the vulcanization accelerator is inaccurate and cannot be used.

Thus, there is a need for an improved method of preparing a vulcanization accelerator standard.

Disclosure of Invention

Aiming at the defects in the prior art, the application aims to provide a method for preparing a vulcanization accelerator standard substance so as to solve the problems in the prior art.

In one aspect of the application, the application provides a method of preparing a vulcanization accelerator standard, the method comprising: a first reactant purification step comprising forming a first reactant alkaline solution and subjecting it to a first adsorption treatment, and adjusting the pH of the solution after the first adsorption treatment to 7.5 to 9, and obtaining a purified first reactant; a synthesis step comprising mixing and reacting the purified first reactant, second reactant, and catalyst to obtain a fresh-made sulfation promoter; and a product purification step, wherein the product purification step comprises the steps of sequentially carrying out second adsorption treatment and recrystallization treatment on the fresh-made sulfation promoter.

Further, the first reactant comprises a sulfhydryl compound and the second reactant comprises an amino compound.

Further, the first reactant purification step comprises: the first reactant is completely dissolved in an alkaline solution to form the first reactant alkaline solution, and the first reactant alkaline solution is subjected to a first filtration treatment.

Further, the alkaline solution comprises an alkali metal carbonate and/or alkali metal hydroxide solution.

Further, the first reactant alkaline solution subjected to the first filtration treatment is supplied to a first chromatographic column to perform the first adsorption treatment.

Still further, the residence time of the first reactant alkaline solution in the first chromatographic column is from 1 to 5 hours.

Further, the first reactant purification step comprises the steps of utilizing an acidic solution to adjust the pH value of the solution after the first adsorption treatment, carrying out second filtering treatment on the solution with the adjusted pH value to obtain a first reactant wet product, carrying out rinsing treatment on the first reactant wet product, and then drying at 60-100 ℃ to obtain the purified first reactant.

Further, the rinsing treatment comprises rinsing with a rinsing liquid to a rinsing effluent pH of 7 to 7.5.

Still further, the rinse solution includes deionized water, and the rinsing process may be performed one or more times.

Further, the drying time of the first reactant wet product is 1-5 h.

Further, the synthesizing step includes: the ratio of the purified first reactant to the second reactant was 1g: (6-20) mL; the reaction is carried out in a high pressure reactor.

Further, a mixture of the purified first reactant, the second reactant, and the catalyst is added to a high pressure reactor, and after continuing mixing, the introduction of an oxygen-containing gas is started.

Still further, the oxygen-containing gas includes pure oxygen, air, ozone, and mixtures thereof.

Further, adding the mixture into the high-pressure reactor, continuously mixing for 1-2.5 h, controlling the reaction temperature to be 35-75 ℃, preferably 45-70 ℃, introducing oxygen-containing gas for reaction, controlling the pressure in the high-pressure reactor to be 0.2-1.5MPa in the reaction process, and cooling after the reaction is carried out for 1-3 h.

Further, the product purification step comprises: and supplying the fresh vulcanization accelerator to a second chromatographic column to perform the second adsorption treatment, collecting overflow liquid at the top of the second chromatographic column, and cooling and stirring to obtain the vulcanization accelerator standard through the recrystallization treatment.

Further, the recrystallization treatment comprises the steps of cooling the liquid obtained by the second adsorption treatment under the ice water bath condition of 5-10 ℃, stirring for 1-5 hours, cooling, crystallizing and separating out, washing with water, and drying at 60-75 ℃ for 3-5 hours to obtain the vulcanization accelerator standard.

Further, the first adsorption treatment is performed by a first chromatographic column, the second adsorption treatment is performed by a second chromatographic column, the first chromatographic column and the second chromatographic column are the same or different, and the filler in the chromatographic column comprises at least one of activated carbon, alumina, silica gel, resin and diatomite.

Further, the catalyst includes at least one of a liquid catalyst and a solid catalyst.

Further, the mercapto compound includes an accelerator 2-mercaptobenzothiazole.

Further, the amino compound includes one of tert-butylamine and cyclohexylamine.

Further, the purity of the obtained vulcanization accelerator standard is not lower than 99.6%.

The beneficial effects of the application include at least one of the following:

1. the method adopts the steps of purifying the first reactant and the newly-prepared vulcanization accelerator respectively, so that the purity of the vulcanization accelerator standard can be improved;

2. the method adopts the step of catalytic synthesis under high pressure condition, and the impurities generated in the synthesis process are less and easy to remove;

3. the method is simple to operate, and the purity of the obtained vulcanization accelerator standard is not lower than 99.6%.

The foregoing summary is for the purpose of the specification only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of the present application will become readily apparent by reference to the following detailed description.

Drawings

In the drawings, there are depicted only some embodiments in accordance with the present disclosure and are not to be considered limiting of the scope of the present disclosure.

FIG. 1 is a flow chart of a method for preparing a vulcanization accelerator standard in accordance with an embodiment of the present application;

FIG. 2 shows the results of liquid chromatography detection of the sample obtained in example 1 of the present application;

FIG. 3 shows the results of liquid chromatography detection of the sample obtained in example 2 of the present application.

Detailed Description

Hereinafter, only certain exemplary embodiments are briefly described. As will be recognized by those of skill in the pertinent art, the described embodiments may be modified in various different ways without departing from the spirit or scope of the present application. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive.

The standard substance is a standard substance, is used as a standard content in content determination in terms of compounds, and has purity of usually more than 98%, and the improvement of the purity of the standard substance is beneficial to improving the accuracy of analysis.

In one aspect of the application, a method of preparing a vulcanization accelerator standard is provided. Referring to fig. 1, the method includes a step of purifying S1 first reactant, a step of synthesizing S2, and a step of purifying S3 product. Wherein the step of purifying the first reactant is used for purifying the first reactant, the step comprises the steps of forming a first reactant alkaline solution and carrying out first adsorption treatment on the first reactant alkaline solution, collecting the solution after the first adsorption treatment and adjusting the pH value of the solution to 7.5-9, and obtaining the purified first reactant for subsequent reactions. The S2 synthesis step is used for synthesizing the vulcanization accelerator, and comprises the steps of mixing and reacting the purified first reactant, the purified second reactant and the purified catalyst to obtain the freshly prepared vulcanization accelerator. And S3, purifying the obtained fresh-made sulphurisation promoter to improve the purity, wherein the step comprises the steps of performing second adsorption treatment on the fresh-made sulphurisation promoter to adsorb impurities to further improve the purity, and then performing recrystallization treatment on the solution subjected to the second adsorption treatment to obtain a standard product of the sulphurisation promoter. Wherein the first reactant comprises a sulfhydryl compound and the second reactant comprises an amino compound. The method has at least the following beneficial effects: the operation is simple, and the standard product of the vulcanization accelerator with the purity not lower than 99.6 percent can be obtained.

The method comprises the steps of firstly purifying a first reactant, controlling synthesis conditions to obtain a new sulfation promoter, and then further purifying the new sulfation promoter. The method can obtain the vulcanization accelerator with higher purity through simple operation, and the obtained vulcanization accelerator can be used as a vulcanization accelerator standard. According to an embodiment of the application, the first reactant may comprise the promoter 2-Mercaptobenzothiazole (MBT). The second reactant may include one of tert-butylamine and cyclohexylamine. The catalyst comprises at least one of a liquid catalyst and a solid catalyst. The solid catalyst includes a supported solid catalyst, i.e., a catalyst in which an active catalytic component is supported on a carrier, for example, a supported catalyst prepared by a volumetric impregnation method and using a molecular sieve, activated carbon, porous ceramic, silica, etc. as a carrier. Wherein the active catalytic ingredient may comprise a heterogeneous catalyst such as copper oxide, copper sulfate, copper acetate, cobalt phthalocyanine, or combinations thereof. The specific components of the above reactants are not particularly limited and may be determined according to the specific composition of the vulcanization accelerator. For example, where the first reactant is accelerator MBT and the second reactant is tert-butylamine, a vulcanization accelerator TBBS may be obtained; when the first reactant is accelerator MBT and the second reactant is cyclohexylamine, a vulcanization accelerator CBS may be obtained.

According to an embodiment of the present application, the first reactant purification step may include completely dissolving the first reactant in the alkaline solution to form a first reactant alkaline solution. The amount of the first reactant used in this step is not particularly limited as long as a sufficient amount of the vulcanization accelerator can be synthesized in the subsequent step according to the embodiment of the present application. The concentration of the base in the alkaline solution and the amount of the alkaline solution forming the alkaline solution of the first reactant are also not particularly limited as long as the first reactant can be completely dissolved in the alkaline solution. Specifically, a sufficient amount of alkaline solution may be added to dissolve the first reactant. And the purified first reactant obtained through the first reactant purification step may be used for a subsequent synthesis reaction or stored in a dryer at normal temperature for a storage time of not more than 6 months.

For example, according to some embodiments of the present application, the alkaline solution includes, but is not limited to, alkali metal carbonate and alkali metal hydroxide solutions, and the like. Specifically, the alkaline solution may be an alkali metal hydroxide solution such as potassium hydroxide, sodium hydroxide, or the like. For example, a 5-15wt% NaOH solution may be used to form the first reactant alkaline solution.

After the formation of the first reactant alkaline solution, the obtained first reactant alkaline solution may be subjected to a first filtration treatment to remove a part of impurities, for example, a part of impurities having low solubility in the alkaline solution, in order to further improve the purity of the obtained vulcanization accelerator standard.

Subsequently, the first reactant alkaline solution may be subjected to a first adsorption treatment, for example, supplied to a first chromatographic column for decolorization. This step can remove impurities still remaining in the solution, for example, side reaction products generated during the reaction, isomers of the target product, and the like. Specifically, impurities including acidic resins, basic resins, anilinobenzothiazoles, and the like may be removed to further increase the purity of the first reactant. Wherein the residence time of the first reactant alkaline solution in the first chromatographic column is 1 to 5 hours, specifically, the residence time may be 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours and 5 hours.

The specific type of the first chromatographic column is not particularly limited as long as it has a certain adsorption property, and decolorization of the alkaline solution of the first reactant can be achieved. For example, the solution may alternatively be supplied to the chromatography column by pumping means including, but not limited to, peristaltic pumps. The filler in the column is not particularly limited, and may be at least one of activated carbon, alumina, silica gel, resin, and diatomaceous earth; the form of the filler is not particularly limited, and may be granular or powdery.

According to an embodiment of the present application, the first reactant purification step further includes an operation of acid-base neutralization reaction of the solution subjected to the first adsorption treatment with an acidic solution. Specifically, an acid may be added to the alkaline solution of the first reactant to adjust the pH to 7.5 to 9, thereby precipitating the first reactant. Since the alkaline solution of the first reactant has been subjected to the first adsorption treatment in advance, the impurity content in the solution before the precipitation of the first reactant has been effectively controlled, so that the first reactant having higher purity can be obtained.

In this step, the acidic solution may be a mineral acid. Including, but not limited to, dilute hydrochloric acid and dilute sulfuric acid, for example. And filtering out the first reactant separated out after the neutralization reaction of the acid and the alkali through a second filtering treatment to obtain a first reactant tide product. The resulting first reactant wet product is subjected to a rinsing treatment to further remove impurities, such as soluble impurities (salts resulting from the acid-base neutralization reaction). Specifically, deionized water may be used as the rinse liquid in the rinsing treatment until the pH of the rinse effluent after rinsing is 7 to 7.5. The amount of the rinse liquid used and the number of the rinse treatments are not particularly limited, and may be specifically determined according to the content of the obtained first reactant wet product. For example, the rinsing treatment may be performed once or repeated a plurality of times. The moisture content of the rinsed first reactant wet product is 10% -20%, and then the first reactant wet product is dried to obtain a dried purified first reactant. Wherein the drying temperature can be 60-100deg.C, such as 60 deg.C, 65 deg.C, 70 deg.C, 75 deg.C, 80 deg.C, 85 deg.C, 90 deg.C, 95 deg.C and 100 deg.C; the drying time may be determined according to the content of the obtained reactant wet product, and may be short in the case of a small content and long in the case of a large content, and may be, specifically, 1 to 5 hours, for example, 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, and 5 hours.

According to embodiments of the present application, the synthesis step may be performed under high pressure conditions in the presence of oxygen. Specifically, the purified first reactant, the purified second reactant and the purified catalyst are mixed in an organic solvent and then injected into a high-pressure reactor for reaction. For example, the aforementioned reactants may be injected into the high pressure reactor and then mixed for 1 to 2.5 hours (e.g., 1 hour, 1.5 hours, 2 hours, and 2.5 hours) to allow sufficient contact between the reactants, and then the temperature in the high pressure reactor may be raised to 35 to 75 ℃, preferably 45 to 70 ℃. After the temperature reaches 35-75 ℃ (preferably 45-70 ℃), oxygen-containing gas can be introduced into the high-pressure reactor. Wherein the oxygen-containing gas comprises at least one of pure oxygen, air, ozone, and mixtures thereof. Specifically, under the condition of non-oxygen synthesis, dibenzothiazyl Disulfide (DM) serving as an impurity promoter is generated, and the purity of the target vulcanization accelerator is affected. However, when the reaction is carried out in the presence of an oxygen-containing gas, the selectivity of the reaction to the target vulcanization accelerator is high, and the impurity accelerator DM is hardly generated. The oxygen-containing gas is preferably an oxygen-containing gas containing no carbon dioxide, and further, the reaction of the amino group in the system with carbon dioxide to produce a carbonate which is difficult to be adsorbed by an adsorption column such as activated carbon, thereby preventing the purity of the vulcanization accelerator standard from being affected.

In the reaction process, the pressure in the high-pressure reactor can be controlled to be 0.2-1.5 MPa. And cooling after the reaction is carried out for a period of time, and reducing the temperature inside the high-pressure reactor to room temperature to terminate the reaction. The reaction time from the oxygen-containing gas to the cooling treatment can be determined according to the content of the reactant, the reaction time is long when the content of the reactant is high, the reaction time is short when the content of the reactant is low, and specifically, the reaction time can be 1-3 h, such as 1h, 1.5h, 2h, 2.5h and 3h.

According to an embodiment of the present application, during the reaction, a chemically inert gas is optionally introduced into the inside of the high pressure reactor to adjust the oxygen concentration. Wherein the chemically inert gas includes, but is not limited to, nitrogen, helium, argon, and the like. In addition, the specific pressure in the high-pressure reactor is not particularly limited, and those skilled in the art can adjust the pressure according to the internal volume of the reactor, the saturated vapor pressure of each reactant, and the like, so long as the pressure is within the range of 0.2 to 1.5MPa. For example, when the oxygen concentration in the introduced oxygen-containing gas is high, the reaction may occur at a lower pressure, but care needs to be taken to be safe in production to prevent the pressure from being exploded improperly. When inert gas with chemical property and oxygen-containing gas are simultaneously introduced into the high-pressure reactor, the oxygen concentration can be controlled through the inert gas with chemical property, the system safety is higher, and the pressure in the reaction kettle can be properly increased so as to promote the reaction. In the specific embodiment, the reaction is preferably performed by simultaneously introducing a chemically inert gas and an oxygen-containing gas containing no carbon dioxide into the high pressure reactor, and the reaction is high in safety and high in reaction selectivity, and the generated impurities are less.

According to the examples of the present application, the content of the reactants used in the synthesis step is not particularly limited as long as the ratio of the purified first reactant to the second reactant dissolved in the organic solvent is 1g: (6-20 mL), for example, 25g of the purified first reactant and 400mL of the second reactant are dissolved in an organic solvent. Wherein the organic solvent can be one of methanol, ethanol or dimethylformamide.

According to the embodiment of the application, fewer impurities are generated in the synthesis step of the method and are easy to remove, and the generated impurities can be removed through the product purification step. Specifically, the product purification step may include a second adsorption treatment and a recrystallization treatment.

According to an embodiment of the present application, the above-described fresh-made thiolation promoter may be first supplied to a second chromatographic column for a second adsorption treatment to remove major impurities (e.g., benzothiazole, etc.) generated during the synthesis. The overflow liquid from the top of the second chromatographic column was collected and subjected to recrystallization treatment to obtain the vulcanization accelerator standard. The filler in the second chromatographic column may be at least one of activated carbon, alumina, silica gel, resin, and diatomaceous earth, and may be in the form of particles or powder. The second chromatographic column may be the same as the first chromatographic column or may be different from the first chromatographic column.

According to an embodiment of the present application, the recrystallization treatment includes subjecting the overflow liquid of the second column to a temperature-decreasing crystallization treatment at a low temperature. Specifically, the temperature is reduced under the ice-water bath condition of 5-10 ℃, for example, a clean flask can be placed in advance under the ice-water bath condition of 5-10 ℃ for precooling, the overflow liquid at the top of the second chromatographic column is poured into the flask, and the liquid is stirred until the product is crystallized and separated, wherein the stirring time can be 1-5 h, for example, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h and 5h, and the stirring can be performed by using an automatic stirrer.

According to an embodiment of the present application, the recrystallization treatment further includes an operation of washing the precipitated product crystals with deionized water and then drying the obtained product crystals at a temperature of 60 to 75 ℃ to obtain a vulcanization accelerator standard. In this step, the drying time is not particularly limited as long as the product crystals are sufficiently dried, and specifically, the drying time may be 3 to 5 hours, for example, 3 hours, 3.5 hours, 4 hours, 4.5 hours, and 5 hours.

According to an embodiment of the present application, the first adsorption treatment and the second adsorption treatment may each be performed one or more times to further improve the purity of the reactant or product, for example, one first adsorption treatment and one second adsorption treatment may be performed.

According to an embodiment of the present application, the filtering material used in the filtering process is not particularly limited, and may be one of a filter membrane, a filter paper, or a filter, and specifically, the filtering material may be selected according to a portion remaining after the filtering, for example, the filtering may be performed using the filter membrane when the filtrate needs to be retained, and the filtering may be performed using the filter paper when the filtrate needs to be removed and the filtered solid portion remains for the subsequent processing. The type of filter material should be selected according to the size of the material to be filtered out. In a specific embodiment, the first filtration treatment may be performed using a 0.2 μm filter membrane to retain the filtrate, and the second filtration treatment may be performed using a 600-800 mesh filter paper to retain the solid matter.

According to the embodiment of the application, the purity of the standard product of the vulcanization accelerator obtained by the method is not lower than 99.6 percent and is approximately 100 percent, and the method can be used for analyzing the purity of the vulcanization accelerator and has higher accuracy.

The methods used in the examples described below are conventional methods unless otherwise indicated, and the reagents used are commercially available reagents unless otherwise indicated. The purity measurement in the application is obtained by adopting a method defined in GB/T21840-2008.

Example 1

The vulcanization accelerator TBBS standard is obtained by the method of the application, and the specific implementation modes are as follows:

a first reactant purification step: 50g of the first reactant accelerator MBT was placed in a beaker, and an aqueous solution of sodium hydroxide was poured into the beaker and stirred until the first reactant accelerator MBT was completely dissolved, to obtain a first reactant accelerator MBT alkaline solution. The resulting first reactant accelerator MBT alkaline solution was subjected to a first filtration treatment using a 0.2 μm filter membrane, and the macroscopic precipitate was filtered off, and the filtrate was collected in a beaker, at which time the filtrate was yellow. Then, the obtained filtrate was supplied to a column packed with powdered activated carbon by a peristaltic pump, and the filtrate was allowed to stand in the column for 5 hours, and colorless and transparent liquid overflowed from the top of the column was collected. And (3) dropwise adding 20% dilute sulfuric acid into the overflow liquid until the pH value is 9, and carrying out neutralization reaction to precipitate the first reactant accelerator MBT. Filtering out the precipitated first reactant accelerator MBT by using 800-mesh filter paper to obtain a first reactant accelerator MBT damp product, rinsing the precipitated first reactant accelerator MBT by using deionized water, and then placing the obtained first reactant accelerator MBT damp product into an oven to be dried for 2 hours at 100 ℃ to obtain the purified first reactant accelerator MBT.

The synthesis steps are as follows: 25g of the purified first reactant accelerator MBT and the supported solid catalyst are premixed in methanol, 400mL of the second reactant tert-butylamine is added into the mixture, the mixture is fully mixed, the mixture is injected into a high-pressure reactor for continuous mixing for 2 hours, the temperature of the high-pressure reactor is increased to 70 ℃, and oxygen-containing gas is introduced into the high-pressure reactor to start the reaction. Controlling the pressure in the high-pressure reactor to be not lower than 0.2MPa, cooling the temperature in the high-pressure reactor to room temperature after the reaction is carried out for 2 hours, and collecting the synthesized new-made sulfation promoter.

And (3) product purification: the collected fresh-made sulfation promoter was put into a beaker, the supported solid catalyst was filtered off with a 600 mesh filter, and the remaining filtrate was fed to a chromatography column filled with powdered activated carbon with a peristaltic pump to adsorb impurities. Collecting the overflow liquid at the top of the chromatographic column, pouring the overflow liquid into a flask with an ice-water bath at 5 ℃, stirring for 2 hours by using an automatic stirrer, filtering out the precipitated vulcanization accelerator by using 800-mesh filter paper, flushing the vulcanization accelerator by using deionized water, and drying the flushed vulcanization accelerator in an oven at 60 ℃ for 3 hours to obtain the vulcanization accelerator TBBS standard.

Purity measurement: the example was repeated several times, and the minimum purity of the obtained vulcanization accelerator TBBS standard was 99.75% by a liquid chromatography analysis method, and the liquid chromatography result chart was as shown in FIG. 2, the peak shape of the target peak was sharp and narrow, and the peak area percentage was 99.82%. Specifically, the chromatogram parameters are shown in table 1 below.

TABLE 1

Example 2

The specific implementation mode of the method is as follows:

a first reactant purification step: the same as in example 1.

The synthesis steps are as follows: 25g of the purified first reactant accelerator MBT and the supported solid catalyst are premixed in methanol, 400mL of the second reactant tert-butylamine is added into the mixture, the mixture is fully mixed and then is injected into a reactor for continuous mixing for 2 hours, and then the temperature of the reactor is increased to 70 ℃, and oxygen-containing gas is introduced into the reactor to start the reaction. Controlling the pressure in the high-pressure reactor to be not lower than 0.46MPa, cooling the temperature in the reactor to room temperature after the reaction is carried out for 2 hours, and collecting the synthesized product.

And (3) product purification: the same as in example 1.

Purity measurement: the example was repeated several times, and the minimum purity of the obtained vulcanization accelerator TBBS standard was 99.70% by a liquid chromatography analysis method, and the liquid chromatography result chart was as shown in FIG. 3, the peak shape of the target peak was sharp and narrow, and the peak area percentage was 99.71%. Specifically, the chromatogram parameters are shown in table 2 below.

TABLE 2

Example 3

The specific implementation mode of the method is as follows:

a first reactant purification step: the procedure of example 1 was repeated except that the filler in the column was diatomaceous earth.

The synthesis steps are as follows: the same as in example 1.

And (3) product purification: the procedure of example 1 was repeated except that the filler in the column was diatomaceous earth.

Purity measurement: the example was repeated several times and the lowest purity of the obtained vulcanization accelerator TBBS standard was 99.71% as determined by liquid chromatography.

Example 4

This example, based on the method of the present application, obtains a vulcanization accelerator TBBS standard by changing the reaction temperature in the synthesis step, and the specific embodiment is as follows:

a first reactant purification step: the same as in example 1.

The synthesis steps are as follows: 25g of the purified first reactant accelerator MBT and the supported solid catalyst are premixed in methanol, 400mL of the second reactant tert-butylamine is added into the mixture, the mixture is fully mixed, the mixture is injected into a high-pressure reactor for continuous mixing for 2 hours, the temperature of the high-pressure reactor is increased to 50 ℃, and oxygen-containing gas is introduced into the high-pressure reactor to start the reaction. Controlling the pressure in the high-pressure reactor to be 0.2-1.5MPa, cooling the temperature in the first high-pressure reactor to room temperature after the reaction is carried out for 2 hours, and collecting the synthesized product.

And (3) product purification: the same as in example 1.

Purity measurement: the example was repeated several times and the lowest purity of the obtained vulcanization accelerator TBBS standard was 99.70% as determined by liquid chromatography.

Comparative example 1

This example, based on the method of the present application, obtains a vulcanization accelerator TBBS standard by changing the pH of the acid-base neutralization reaction in the first reactant purification step, and the specific embodiment is as follows:

a first reactant purification step: 50g of the first reactant accelerator MBT was placed in a beaker, and an aqueous solution of sodium hydroxide was poured into the beaker and stirred until the first reactant accelerator MBT was completely dissolved, to obtain a first reactant accelerator MBT alkaline solution. The resulting basic solution of the first reactant promoter MBT was subjected to a first filtration treatment using a 0.2 μm filter membrane, the impurities were filtered off, and the filtrate was collected in a beaker, at which time the filtrate was yellow. Then, the obtained filtrate was supplied to a column packed with powdered activated carbon by a peristaltic pump, and the filtrate was allowed to stand in the column for 5 hours, and colorless and transparent liquid overflowed from the top of the column was collected. And (3) dropwise adding 20% dilute sulfuric acid into the obtained overflow liquid until the pH value is 7, and carrying out neutralization reaction to precipitate the first reactant accelerator MBT. Filtering out the precipitated first reactant accelerator MBT by using 800-mesh filter paper to obtain a first reactant accelerator MBT damp product, rinsing the precipitated first reactant accelerator MBT by using deionized water, and then placing the obtained first reactant accelerator MBT damp product into an oven to be dried for 2 hours at 100 ℃ to obtain the purified first reactant accelerator MBT.

The synthesis steps are as follows: the same as in example 1.

And (3) product purification: the same as in example 1.

Purity measurement: at pH 7, the acidic resin precipitates with the first reactant-accelerator MBT, reducing the purity of the first reactant-accelerator MBT. The example was repeated several times and the lowest purity of the obtained vulcanization accelerator TBBS standard was 97.60% as determined by liquid chromatography.

Comparative example 2

This comparative example, based on example 1, a vulcanization accelerator TBBS standard was obtained by not subjecting the first reactant accelerator MBT and the product to adsorption treatment, and the specific embodiments are as follows:

a first reactant purification step: 50g of the first reactant accelerator MBT was placed in a beaker, and an aqueous solution of sodium hydroxide was poured into the beaker and stirred until the first reactant accelerator MBT was completely dissolved, to obtain a first reactant accelerator MBT alkaline solution. The obtained basic solution of the first reactant accelerator MBT is subjected to first filtration treatment by using a filter membrane with the diameter of 0.2 mu m, impurities are filtered, a beaker is used for collecting filtrate, 20% dilute sulfuric acid is dripped into the filtrate until the pH value is 9, and the first reactant accelerator MBT is separated out through neutralization reaction. Filtering out the precipitated first reactant accelerator MBT by using 800-mesh filter paper to obtain a first reactant accelerator MBT damp product, rinsing the precipitated first reactant accelerator MBT by using deionized water, and then placing the obtained first reactant accelerator MBT damp product into an oven to be dried for 2 hours at 100 ℃ to obtain the purified first reactant accelerator MBT.

The synthesis steps are as follows: the same as in example 1.

And (3) product purification: and (3) putting the collected synthetic product into a beaker, filtering the supported solid catalyst by using a 600-mesh filter, pouring the filtrate into a flask with an ice-water bath at the temperature of 5 ℃, stirring for 2 hours by using an automatic stirrer, filtering out the precipitated vulcanization accelerator by using 800-mesh filter paper, flushing the vulcanization accelerator by using deionized water, and putting the flushed vulcanization accelerator into a baking oven to dry for 3 hours at the temperature of 60 ℃ to obtain a vulcanization accelerator standard.

Purity measurement: the example was repeated several times and the lowest purity of the obtained vulcanization accelerator TBBS standard was 97.00% as determined by liquid chromatography.

Comparative example 3

This comparative example obtains a vulcanization accelerator TBBS standard by directly mixing and reacting an alkaline solution of a first reactant accelerator MBT with a mixed solution of a second reactant tert-butylamine and an acidic solution, and the specific embodiments are as follows:

50g of the first reactant accelerator MBT was placed in a beaker, and an aqueous solution of sodium hydroxide was poured into the beaker and stirred until the first reactant accelerator MBT was completely dissolved, to obtain a first reactant accelerator MBT alkaline solution. An acidic solution was added to 400mL of the second reactant t-butylamine to obtain a mixture of the second reactant t-butylamine and the acidic solution. Mixing a first reactant accelerator MBT alkaline solution, a mixed solution of a second reactant tert-butylamine and an acidic solution and a supported solid catalyst in methanol, injecting the mixture into a high-pressure reactor for continuous mixing for 2 hours, then raising the temperature of the high-pressure reactor to 70 ℃, and introducing oxygen into the high-pressure reactor to start the reaction. Controlling the pressure in the high-pressure reactor to be 0.2-1.5MPa, cooling the temperature in the high-pressure reactor to room temperature after the reaction is carried out for 2 hours, and collecting the synthesized product.

And (3) product purification: the same as in example 1.

Purity measurement: a large amount of water exists in the reaction system, and the reaction efficiency is low. The example was repeated several times and the lowest purity of the obtained vulcanization accelerator TBBS standard was determined to be 12.6% by liquid chromatography.

Comparative example 4

In this comparative example, the first reactant MBT was not subjected to the adsorption treatment based on example 1, and the specific embodiment is as follows:

The synthesis steps are as follows: the same as in example 1.

And (3) product purification: the same as in example 1.

Purity measurement: the example was repeated several times and the lowest purity of the resulting vulcanization accelerator standard was 98.00% as determined by liquid chromatography.

Comparative example 5

This comparative example was based on example 1, wherein the vulcanization accelerator TBBS standard was obtained by subjecting the product to 2 times of adsorption treatment without subjecting the first reactant accelerator MBT to adsorption treatment, and the specific embodiments are as follows:

a first reactant purification step: the same as in comparative example 4.

The synthesis steps are as follows: the same as in comparative example 4.

And (3) product purification: the collected synthetic product was placed in a beaker, the supported solid catalyst was filtered off with a 600 mesh filter, and the remaining filtrate was fed to a chromatography column packed with powdered activated carbon with a peristaltic pump to adsorb impurities. The liquid overflowed from the top of the chromatographic column is collected and supplied again to a new chromatographic column filled with powdered activated carbon by a peristaltic pump to further adsorb impurities. Collecting the overflow liquid at the top of the chromatographic column, pouring the overflow liquid into a flask with an ice-water bath at 5 ℃, stirring for 2 hours by using an automatic stirrer, filtering out the precipitated vulcanization accelerator by using 800-mesh filter paper, flushing the vulcanization accelerator by using deionized water, and drying the flushed vulcanization accelerator in an oven at 60 ℃ for 3 hours to obtain a vulcanization accelerator standard product.

Purity measurement: the example was repeated several times and the lowest purity of the obtained vulcanization accelerator TBBS standard was 98.6% as determined by liquid chromatography.

Comparative example 6

The comparative example is a commercial vulcanization accelerator TBBS purified by a primary adsorption treatment, and the specific embodiment is as follows:

a commercially available vulcanization accelerator TBBS was dissolved in methanol, and the resulting solution was fed to a column packed with powdered activated carbon by a peristaltic pump for adsorption. Collecting the overflow liquid at the top of the chromatographic column, pouring the overflow liquid into a flask with an ice-water bath at 5 ℃, stirring for 2 hours by using an automatic stirrer, filtering out the precipitated vulcanization accelerator by using 800-mesh filter paper, flushing the vulcanization accelerator by using deionized water, and drying the flushed vulcanization accelerator in an oven at 60 ℃ for 3 hours to obtain a vulcanization accelerator standard product.

Purity measurement: the purity of the standard obtained in this comparative example is affected by the process of the commercial product. The example was repeated several times and the lowest purity of the obtained vulcanization accelerator TBBS standard was 97.00% as determined by liquid chromatography.

Comparative example 7

The comparative example is a commercial vulcanization accelerator TBBS purified by two adsorption treatments, and the specific embodiments are as follows:

a commercially available vulcanization accelerator TBBS was dissolved in methanol, and the resulting solution was fed to a column packed with powdered activated carbon by a peristaltic pump for adsorption. The liquid overflowed from the top of the chromatographic column is collected and supplied again to a new chromatographic column filled with powdered activated carbon by a peristaltic pump to further adsorb impurities. Collecting the overflow liquid at the top of the chromatographic column, pouring the overflow liquid into a flask with an ice-water bath at 5 ℃, stirring for 2 hours by using an automatic stirrer, filtering out the precipitated vulcanization accelerator by using 800-mesh filter paper, flushing the vulcanization accelerator by using deionized water, and drying the flushed vulcanization accelerator in an oven at 60 ℃ for 3 hours to obtain a vulcanization accelerator standard product.

Purity measurement: the purity of the standard obtained in this comparative example is affected by the process of the commercial product, but the multiple adsorption effect is not obvious. The example was repeated several times and the lowest purity of the obtained vulcanization accelerator TBBS standard was 97.30% as determined by liquid chromatography.

Example 5

The CBS standard of the vulcanization accelerator is obtained by the method disclosed by the application, and the concrete implementation modes are as follows:

The synthesis steps are as follows: 25g of the purified first reactant accelerator MBT and the supported solid catalyst are premixed in methanol, 400mL of second reactant cyclohexylamine is added into the mixture, after the mixture is fully mixed, the mixture is injected into a high-pressure reactor for continuous mixing for 2 hours, and then the temperature of the high-pressure reactor is increased to 70 ℃, and oxygen-containing gas is introduced into the high-pressure reactor to start the reaction. Controlling the pressure in the high-pressure reactor to be not lower than 0.2MPa, cooling the temperature in the high-pressure reactor to room temperature after the reaction is carried out for 2 hours, and collecting the synthesized new-made sulfation promoter.

And (3) product purification: the collected fresh-made sulfation promoter was put into a beaker, the supported solid catalyst was filtered off with a 600 mesh filter, and the remaining filtrate was fed to a chromatography column filled with powdered activated carbon with a peristaltic pump to adsorb impurities. Collecting the overflow liquid at the top of the chromatographic column, pouring the overflow liquid into a flask with an ice-water bath at 5 ℃, stirring for 2 hours by using an automatic stirrer, filtering out the precipitated vulcanization accelerator by using 800-mesh filter paper, flushing the vulcanization accelerator by using deionized water, and drying the flushed vulcanization accelerator in an oven at 60 ℃ for 3 hours to obtain the vulcanization accelerator CBS standard.

Purity measurement: the example was repeated several times and the lowest purity of the resulting vulcanization accelerator CBS standard was 99.6% as determined by liquid chromatography.

According to embodiments of the present application, the method may be used to obtain a standard including, but not limited to, a vulcanization accelerator TBBS or CBS, other chemicals, and other chemicals may be purified by the reactant purification step of the method, or by the product purification step of the method.

In general, the method for obtaining the standard product of the vulcanization accelerator provided by the application is simple to operate, adopts the steps of catalytic synthesis under high pressure, and purifying reactants and products respectively, and uses high-purity reactants for reaction. The method has the advantages that the impurities generated in the synthesis process are few and easy to remove, and the vulcanization accelerator standard with the purity not lower than 99.6% can be obtained.

While the fundamental and principal features of the application and advantages of the application have been shown and described, it will be apparent to those skilled in the art that the application is not limited to the details of the foregoing exemplary embodiments, but may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Accordingly, the embodiments are to be considered in all respects as illustrative and not restrictive.

Furthermore, it should be understood that although the present disclosure describes embodiments, not every embodiment is provided with a separate embodiment, and that this description is provided for clarity only, and that the disclosure is not limited to the embodiments described in detail below, and that the embodiments described in the examples may be combined as appropriate to form other embodiments that will be apparent to those skilled in the art.

Claims

1. A method of preparing a vulcanization accelerator standard, comprising:

a first reactant purification step comprising forming a first reactant alkaline solution and subjecting it to a first adsorption treatment, and adjusting the pH of the solution after the first adsorption treatment to 7.5 to 9, and obtaining a purified first reactant;

a synthesis step comprising mixing and reacting the purified first reactant, second reactant, and catalyst to obtain a fresh-made sulfation promoter;

a product purification step comprising sequentially performing a second adsorption treatment and a recrystallization treatment on the fresh-made sulfation promoter;

wherein the first reactant comprises a sulfhydryl compound and the second reactant comprises an amino compound.

2. The method of claim 1, wherein the first reactant purifying step comprises:

completely dissolving the first reactant in an alkaline solution to form the first reactant alkaline solution, and performing a first filtration treatment on the first reactant alkaline solution;

optionally, the alkaline solution comprises an alkali metal carbonate and/or alkali metal hydroxide solution;

supplying the first reactant alkaline solution subjected to the first filtration treatment to a first chromatographic column to perform the first adsorption treatment;

optionally, the residence time of the first reactant alkaline solution in the first chromatographic column is 1 to 5 hours.

3. The method according to claim 1, wherein the first reactant purification step comprises pH-adjusting the solution after the first adsorption treatment with an acidic solution, and performing a second filtration treatment on the pH-adjusted solution to obtain a first reactant wet product, rinsing the first reactant wet product, and then drying at 60-100 ℃ to obtain the purified first reactant;

optionally, the rinsing treatment comprises rinsing with a rinsing liquid until the pH value of the rinsing effluent is 7-7.5;

optionally, the rinse solution comprises deionized water, and the rinsing treatment may be performed one or more times;

optionally, the first reactant tide product is dried for 1-5 h.

4. The method of claim 1, wherein the synthesizing step comprises:

the ratio of the purified first reactant to the second reactant was 1g: (6-20) mL;

the reaction is carried out in a high pressure reactor;

optionally, adding a mixture of the purified first reactant, the second reactant and the catalyst to a high pressure reactor, and beginning to introduce oxygen-containing gas after continuing mixing;

further optionally, the oxygen-containing gas comprises pure oxygen, air, ozone, and mixtures thereof.

5. The method according to claim 4, wherein the mixture is added to the high-pressure reactor and mixed for 1 to 2.5 hours, the reaction temperature is controlled to be 35 to 75 ℃, preferably 45 to 70 ℃, the oxygen-containing gas is introduced to react, the pressure in the high-pressure reactor is controlled to be 0.2 to 1.5MPa during the reaction, and the temperature reduction treatment is performed after the reaction is performed for 1 to 3 hours.

6. The method of claim 1, wherein the product purification step comprises: and supplying the fresh vulcanization accelerator to a second chromatographic column to perform the second adsorption treatment, collecting overflow liquid at the top of the second chromatographic column, and cooling and stirring to obtain the vulcanization accelerator standard through the recrystallization treatment.

7. The method according to claim 1, wherein the recrystallization treatment comprises cooling the liquid obtained by the second adsorption treatment under the ice water bath condition of 5-10 ℃, stirring for 1-5 hours, cooling, crystallizing and separating out, washing with water, and drying at 60-75 ℃ for 3-5 hours to obtain the vulcanization accelerator standard.

8. The method of claim 1, wherein the first adsorption treatment is performed using a first chromatographic column and the second adsorption treatment is performed using a second chromatographic column, the first and second chromatographic columns being the same or different, and wherein the packing in the chromatographic column comprises at least one of activated carbon, alumina, silica gel, resin, diatomaceous earth.

9. The method of claim 1, wherein the method satisfies one or more of the following conditions:

the catalyst comprises at least one of a liquid catalyst and a solid catalyst;

the mercapto compound comprises an accelerator 2-mercaptobenzothiazole;

the amino compound includes one of tert-butylamine and cyclohexylamine.

10. The method of claim 1, wherein the obtained vulcanization accelerator standard has a purity of not less than 99.6%.