CN101260087A

CN101260087A - Method for purifying rubber vulcanization accelerator MBT

Info

Publication number: CN101260087A
Application number: CNA2008100528197A
Authority: CN
Inventors: 王树华; 孟庆保; 洪学斌; 孙凤娟; 王树领; 王树恒
Original assignee: TIANJIN KEMAI CHEMICAL CO Ltd
Current assignee: TIANJIN KEMAI CHEMICAL CO Ltd
Priority date: 2008-04-21
Filing date: 2008-04-21
Publication date: 2008-09-10

Abstract

The invention discloses a purification method for a rubber vulcanization accelerator MBT. The process of the method is as follows: 10 to 500 g of crude MBT with the mass percentage of 40 to 70 percent is made a temperature rise to 200 to 500 DEG C, and then is aerated into a reactor filled with 100 to 2000 ml of distilled water with the temperature of 20 to 50 DEG C, the temperature of the MBT is quickly decreased to 30 to 80 DEG C, NaOH solution with the mass percentage of 3 to 50 percent is dropped into the reactor in a 20 to 500 ml/min flow rate, and the reaction terminal is reached when the pH value of the solution is between 8 and 14; the solution is added into toluene with the temperature of 20 to 80 DEG C, extracted for 5 to 300 minutes, and is placed for 5 to 300 minutes; M-Na salt solution is added into a beaker, sulfuric acid solution with the mass percentage of 5 to 50 percent is dropped into the beaker, the reaction terminal is reached when the pH value is between 3 and 7, the filtration and the drying are made to obtain the vulcanization accelerator MBT with the content higher than 99 percent. The method has the advantages that: the method has a simple process and is easy to be industrialized; the produced high-content MBT has the purity high up to above 99 percent, high melting point, short melting range and high yield.

Description

The method of purification of rubber vulcanization accelerant MBT

Technical field

The present invention relates to the method for purification of a kind of thiofide 2-mercaptobenzothiazole (MBT), belong to rubber vulcanization accelerant MBT purification techniques field.

Background technology

Along with the development of rubber industry, the research of vulcanization accelerator more and more is subject to 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.Generally, the impurity in this promotor is mainly resin and intermediate product (as benzothiazole), and the existence of impurity makes quality product not high.Document (fine chemical material and intermediate, 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 toluene aqueous phase extracted; 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 making with extra care is not high.Document (rubber ingredients, 2003,2:21) reported the method for purification MBT from waste water.Thick MBT is dissolved with sodium hydroxide solution, leave standstill after-filtration, reaching the purpose of removing resin, in filtrate, add dilute sulphuric acid MBT is separated out, obtain purified MBT after filtering, be washed to neutrality.Making with extra care out the MBT that foreign matter content is low, fusing point is high, melting range is short is the key that realizes refining MBT widespread use.

Summary of the invention

The object of the present invention is to provide a kind of method of purification of rubber vulcanization accelerant MBT, this method is simple to operate, and MBT purity height, the fusing point height that makes, melting range is short, yield is high.

For achieving the above object, the present invention is realized by following technical proposals: a kind of method of purification of rubber vulcanization accelerant MBT is characterized in that comprising following process:

1. be that 40～70% thick MBT is warming up to 200～500 ℃ with 10～500 grams, mass percent, feed then and be equipped with in 20～50 ℃, the reactor of 100～2000 ml distilled waters, the MBT temperature is dropped to 30～80 ℃ rapidly, with mass percent 3～50% NaOH solution, flow velocity with 20～500ml/min is added drop-wise in the reactor, when solution Ph value is 8～14, reach reaction end;

2. in above-mentioned solution joins 20～80 ℃ toluene, extracted 5～300 minutes, left standstill 5～300 minutes;

3. the M-Na salts solution being put into beaker, is 5～50% sulphuric acid soln to wherein dripping mass percent, when the Ph value is 3～7, reaches reaction end, filters, drying, at this moment obtains content and is higher than 99% accelerator M BT.

The invention has the advantages that: this procedure is simple, is easy to industrialization, and prepared high-content MBT purity reaches more than 99%, fusing point is high, melting range is short, yield is high.

Embodiment

Example 1:

At 270～280 ℃, carry out condensation reaction under pressure 9～10Mpa condition with aniline and curing charcoal, sulphur, generate mass content and be 55% thick MBT, all the other impurity comprise: resin 40%, intermediate product 5%.With 100 grams, mass percent is that 55% thick MBT is warming up to 200 ℃, feed then and be equipped with in 40 ℃, the reactor of 100 ml distilled waters, the MBT temperature is dropped to 30 ℃ rapidly, with mass percent 30% NaOH solution, flow velocity with 200ml/min is added drop-wise in the reactor, when solution Ph value is 12, reach reaction end; In above-mentioned solution joins 50 ℃ toluene, extracted 80 minutes, left standstill 80 minutes; The M-Na salts solution is put into beaker, is 5% sulphuric acid soln to wherein dripping mass percent, when the Ph value is 3, reaches reaction end, filters, drying, at this moment obtains the accelerator M BT of 54.8 grams.The mass content of this 2-mercaptobenzothiazole promotor is 99.6%, fusing point is 182.3 ℃.

Example 2:

The thick MBT that present embodiment adopted is identical with embodiment 1, and the quality percentage composition that is thick MBT is 65%, and all the other impurity comprise: resin 31%, intermediate product 4%.With 200 grams, mass percent is that 65% thick MBT is warming up to 210 ℃, feed then and be equipped with in 30 ℃, the reactor of 500 ml distilled waters, the MBT temperature is dropped to 40 ℃ rapidly, with mass percent 50% NaOH solution, flow velocity with 100ml/min is added drop-wise in the reactor, when solution Ph value is 13, reach reaction end; In above-mentioned solution joins 40 ℃ toluene, extracted 60 minutes, left standstill 60 minutes; The M-Na salts solution is put into beaker, is 35% sulphuric acid soln to wherein dripping mass percent, when the Ph value is 4, reaches reaction end, filters, drying, at this moment obtains the accelerator M BT of 129.1 grams.The mass content of this 2-mercaptobenzothiazole promotor is 99.8%, fusing point is 182.1 ℃.

Example 3:

The thick MBT that present embodiment adopted is identical with embodiment 1, and the quality percentage composition that is thick MBT is 70%, and all the other impurity comprise: resin 28%, intermediate product 2%.With 500 grams, mass percent is that 70% thick MBT is warming up to 230 ℃, feed then and be equipped with in 20 ℃, the reactor of 1000 ml distilled waters, the MBT temperature is dropped to 50 ℃ rapidly, with mass percent 30% NaOH solution, flow velocity with 500ml/min is added drop-wise in the reactor, when solution Ph value is 8, reach reaction end; In above-mentioned solution joins 80 ℃ toluene, extracted 100 minutes, left standstill 100 minutes; The M-Na salts solution is put into beaker, is 50% sulphuric acid soln to wherein dripping mass percent, when the Ph value is 7, reaches reaction end, filters, drying, at this moment obtains the accelerator M BT of 348.0 grams.The mass content of this 2-mercaptobenzothiazole promotor is 99.7%, fusing point is 182.8 ℃.

Claims

1. the method for purification of a rubber vulcanization accelerant MBT is characterized in that comprising following process:

1) be that 40～70% thick MBT is warming up to 200～500 ℃ with 10～500 grams, mass percent, feed then and be equipped with in 20～50 ℃, the reactor of 100～2000 ml distilled waters, the MBT temperature is dropped to 30～80 ℃ rapidly, with mass percent 3～50% NaOH solution, flow velocity with 20～500ml/min is added drop-wise in the reactor, when solution Ph value is 8～14, reach reaction end;

2) in above-mentioned solution joins 20～80 ℃ toluene, extracted 5～300 minutes, left standstill 5～300 minutes;

3) the M-Na salts solution being put into beaker, is 5～50% sulphuric acid soln to wherein dripping mass percent, when the Ph value is 3～7, reaches reaction end, filters, drying, at this moment obtains content and is higher than 99% accelerator M BT.