CN102827102A - Refinement method of rubber vulcanization accelerator MBT (2-mercaptobenzthiazole) - Google Patents

Abstract

The invention relates to a refinement method of a rubber vulcanization accelerator MBT (2-mercaptobenzthiazole), which comprises the following steps: adding crude MBT into a reactor filled with a 2-30 wt% NaOH solution, and keeping the temperature in the reactor at 60-90 DEG C until the MBT is dissolved into an M-Na salt solution and the end point pH value of the solution is kept at 9.5-12.5; diluting the solution with water by 2-5 times, cooling to 40-60 DEG C, and adding an oxidizer to carry out oxidation for 20-40 minutes so as to extract the resin, wherein the oxidizer is a 0.5-15 wt% oxydol solution; and filtering the M-Na salt solution, putting the filtered M-Na salt solution in a reactor, dropwisely adding a 5-25 wt% sulfuric acid solution, reaching the reaction end point when the pH value is 3-7, filtering, and drying. The method is simple, and can easily implement industrialization; and the prepared MBT has the purity of higher than 98%, and has the advantages of high melting point, short melting range and high yield.

Description

The process for purification of rubber vulcanization accelerant MBT

Technical field

The present invention relates to the process for purification of a kind of rubber vulcanization accelerant MBT (chemical name is the 2-benzothiazolyl mercaptan), specifically, relate to a kind of method of purification of producing MBT, belong to the accelerant MBT production technical field from bullion MBT.

Background technology

Along with the development of rubber industry, the research of vulcanization accelerator more and more receives people's attention with production.Vulcanization accelerator plays important effect in vulcanization of rubber process; It can accelerate the reaction of rubber and vulcanizing agent greatly; Boost productivity, also can improve the physical and mechanical properties of vulcanized rubber simultaneously, MBT is the requisite a kind of primary accelerator of present rubber industry; Itself can be used as promotor use, is the main raw material of producing other multiple promotor simultaneously.Generally; Accelerant MBT is pressed into by height and obtains bullion; The impurity that contains in the bullion is mainly resin and intermediate product (like benzothiazole); The mass content of MBT generally about 75～90%, can not satisfy request for utilization, therefore must be through using as industrial goods after refining the purification.The process for refining of bullion MBT roughly can be divided into two types of acid-base method and solvent methods, and the classical acid alkaline process uses the air blast oxidation, produces large quantity of exhaust gas, and water consumption is big, and operation of equipment is simple; The solvent method water consumption is little, but the use of solvent has increased production danger, the infringement enterprise employee health, and also residual solvent has certain harm to human body and product use in the product.Document (fine chemical material and midbody, 2003,1:40) reported the method for refining MBT.Thick MBT melt is dissolved in the mixture of toluene and aqueous sodium hydroxide solution, is separated, use the extracted in toluene water; With sulfuric acid MBT is precipitated out from the MBT sodium salt solution, can obtains purified MBT.This method can only be removed a spot of resin and impurity, and the MBT purity after refining is not high, and soda acid uses the cost height simultaneously with solvent.Document (CN 102250036A) has been reported the exquisite method of a kind of MBT.Thick MBT is dissolved in 10% the sodium hydroxide solution, oxidation 40-50 minute, obtains the M sodium salt; Splash into the dilute sulphuric acid that proportion is 0.8-1.0, oxidation was filtered the back and is added the dilute sulphuric acid neutralization that proportion is 1.1-1.3 after 30 minutes, obtained purified MBT.This technology length consuming time, production cost is higher relatively.Therefore, simple, safety and environmental protection, exquisite purifying technique is the key that realizes the MBT widespread use efficiently.

Summary of the invention

The object of the present invention is to provide a kind of process for refining and purifying of rubber vulcanization accelerant MBT, this technological operation is simple, and cost is low, and environmental pollution is little, and the MBT purity that makes is high, fusing point is high, melting range is short, yield is high.

For achieving the above object, the present invention realizes through following technical proposals.

Concrete technical scheme is following:

A kind of process for purification of rubber vulcanization accelerant MBT uses ydrogen peroxide 50 to be oxygenant purification MBT product, and step is following:

1) thick MBT is joined in the reactor drum of the NaOH solution that mass content 2～30% is housed, reactor temperature is maintained 60～90 ℃, make the MBT dissolving be prepared into the M-Na salts solution, the endpoint pH of this solution remains on 9.5-12.5;

2) with 2～5 times of above-mentioned solution with water dilutions, be cooled to 40～60 ℃ after, add the oxygenant oxidation and extract resin, oxygenant is the hydrogen peroxide solution of mass content 0.5～15%, oxidization time 20-40 minute;

3) putting into reactor drum after the M-Na salts solution is filtered, is 5～25% sulphuric acid soln to wherein dripping mass percent, when pH value is 3～7, reaches reaction end, and at this moment filtration, drying obtain purity and be higher than 98% accelerator M BT.

The invention has the advantages that: this procedure is simple, is easy to industriallization, prepared MBT purity up to more than 98%, fusing point is high, melting range is short, yield is high.

Accelerant MBT purifying technique provided by the invention is simple to operate, and the air blast technology of having forgone traditional has significantly reduced the generation of " three wastes ", environmental friendliness, and the products obtained therefrom quality is good, yield is high.

Embodiment

Through concrete embodiment the present invention is made further detailed description below:

Following examples can make those skilled in the art more comprehensively understand the present invention, but do not limit the present invention in any way.

Embodiment 1

Thick MBT is joined in the reactor drum of the NaOH solution that mass content 30% is housed, reactor temperature is maintained 90 ℃, make the MBT dissolving be prepared into the M-Na salts solution, the endpoint pH of this solution remains on 12.5; With 2 times of above-mentioned solution dilutions, after solution is cooled to 60 ℃, adds the oxygenant oxidation and extract resin, oxygenant is the hydrogen peroxide solution of mass content 15%, oxidization time 40 minutes; Putting into beaker after the M-Na salts solution filtered, is 25% sulphuric acid soln to wherein dripping mass percent, when pH value is 7, reach reaction end, and at this moment filtration, drying obtain MBT product purity 98.1%.

Embodiment 2:

Thick MBT is joined in the reactor drum of the NaOH solution that mass content 20% is housed, reactor temperature is maintained 60 ℃, make the MBT dissolving be prepared into the M-Na salts solution, the endpoint pH of this solution remains on 9.5; With 5 times of above-mentioned solution dilutions, after solution is cooled to 40 ℃, adds the oxygenant oxidation and extract resin, oxygenant is the hydrogen peroxide solution of mass content 0.5%, oxidization time 20 minutes; Putting into beaker after the M-Na salts solution filtered, is 5% sulphuric acid soln to wherein dripping mass percent, when pH value is 3, reaches reaction end, and at this moment filtration, drying obtain MBT product purity 98.8%.

Embodiment 3:

Thick MBT is joined in the reactor drum of the NaOH solution that mass content 2% is housed, reactor temperature is maintained 70 ℃, make the MBT dissolving be prepared into the M-Na salts solution, the endpoint pH of this solution remains on 10.5; With 4 times of above-mentioned solution dilutions, after solution is cooled to 50 ℃, adds the oxygenant oxidation and extract resin, oxygenant is the hydrogen peroxide solution of mass content 10%, oxidization time 25 minutes; Putting into beaker after the M-Na salts solution filtered, is 15% sulphuric acid soln to wherein dripping mass percent, when pH value is 4, reaches reaction end, and at this moment filtration, drying obtain MBT product purity 99%.

Embodiment 4:

Thick MBT is joined in the reactor drum of the NaOH solution that mass content 3% is housed, reactor temperature is maintained 80 ℃, make the MBT dissolving be prepared into the M-Na salts solution, the endpoint pH of this solution remains on 11; With 3 times of above-mentioned solution dilutions, after solution is cooled to 45 ℃, adds the oxygenant oxidation and extract resin, oxygenant is the hydrogen peroxide solution of mass content 2%, oxidization time 25 minutes; Putting into beaker after the M-Na salts solution filtered, is 8% sulphuric acid soln to wherein dripping mass percent, when pH value is 6, reaches reaction end, and at this moment filtration, drying obtain MBT product purity 99.1%.

Although above the preferred embodiments of the present invention are described; But the present invention is not limited to above-mentioned embodiment, and above-mentioned embodiment only is schematically, is not restrictive; Those of ordinary skill in the art is under enlightenment of the present invention; Not breaking away under the scope situation that aim of the present invention and claim protect, can also make the concrete conversion of a lot of forms, these all belong within protection scope of the present invention.

Claims (2)

1. the process for purification of a rubber vulcanization accelerant MBT is characterized in that using the method for ydrogen peroxide 50 as oxygenant purification MBT product, and this method obtains finished product through the molten preparation of alkali M-Na salts solution, hydrogen peroxide oxidation purification, neutralization.

2. the method for claim 1 is characterized in that step is following:

1) thick MBT is joined in the reactor drum of the NaOH solution that mass content 2～30% is housed, reactor temperature is maintained 60～90 ℃, make the MBT dissolving be prepared into the M-Na salts solution, the endpoint pH of this solution remains on 9.5-12.5;

2) with 2～5 times of above-mentioned solution with water dilutions, be cooled to 40～60 ℃ after, add the oxygenant oxidation and extract resin, oxygenant is the hydrogen peroxide solution of mass content 0.5～15%, oxidization time 20-40 minute;

3) putting into reactor drum after the M-Na salts solution is filtered, is 5～25% sulphuric acid soln to wherein dripping mass percent, when pH value is 3～7, reaches reaction end, and at this moment filtration, drying obtain purity and be higher than 98% accelerator M BT.