Rubber Accelerator MBT(M)

Rubber Accelerator MBT(M)

Chemical Name: 2-Mercaptobenzothiazole
Molecular Formula: C7H5NS2
Molecular Weight: 167.26
Gravity: 1.42
CAS NO.: 149-30-4
Package: 25kg/bag
Storage Life: 24months
Chat Now

Product Details

Description:

MBT(M)


Accelerator Chemical Name2-Mercaptobenzothiazole
Molecular Formula C7H5NS2
Molecular Structureimage001.png
Molecular Weight167.26
Gravity1.42
CAS NO.149-30-4
Package25kg/bag
Storage Life24 months


Specification:



Item

Powder

Oil powder

Granular

Appearance

Yellow or pale yellow

Yellow or pale yellow

Yellow or pale yellow

Initial M.P. (Min) ≥ °C

171

171

171

Loss on drying (Max) ≤ %

0.40

0.40

0.40

Ash (Max) ≤ %

0.30

0.30

0.30

Residue on 100 μm sieve (Max) ≤ %

0.5

-

-

Granular diameter mm

-

-

1.5-3

Broken strength N

-

-

2-5

Oil content  %

-

1.0-2.0

-



According to the raw material route, there are mainly:

1) Aniline method;

2) o-nitrophenyl chloride method;

3) N-methylaniline method;

4) N,N-dimethylformamide method;

5) dimethylamine method;

6) haloaniline method;

7) benzothiazole method;

8) o-chlorothiophenol method;

9) Nitrobenzene method and the like.

The specific synthesis process of the rubber vulcanization accelerator M is: molten sulfur, aniline, CS2, benzothiazole is added to the high pressure reaction kettle with stirring, the reaction temperature is 250 ° C, the pressure is 5.87 MPa, after the reaction is finished, the pressure is released, the gas phase Part of the generated H2S and unreacted CS2 enter the sulfur recovery unit and the CS2 recovery unit. The molten M enters the dissolution tank and is dissolved with a NaOH solution, and the insoluble matter is removed by filtration. The filtrate was extracted with toluene to recover by-product benzothiazole and other tars. The toluene layer enters the solvent recovery process to recover benzene. The water layer is a M sodium salt solution. According to the needs of the downstream M derivative products, it can be directly used after concentration, and can also be acidified by acid, and then dried to obtain dry crystal M.

Ways to reduce costs:

The by-product benzothiazole was returned to the reaction vessel. The first is to refine the by-product tar, extract the benzothiazole by-product, and then: return it to the reactor. The second is to use the solvent to recover the refined crude M, avoiding the unnecessary consumption of the chemical refining process, and providing a simple and feasible process for industrial production. The by-product tar in the production process of M is mostly benzothiazole, followed by aniline, thioresordiurea and the like. According to the literature, benzothiazole is an intermediate product of M. Benzothiazole and thioresorthene can form M by adding S and CS2/S.

Refining of the reaction mixture:

Solvent extraction is used to recover the by-product benzothiazole and to refine the M sodium salt. The solvent used may be: monochlorobenzene, o-dichlorobenzene, toluene, benzene, CS2 and polychloroethane.

extraction:

During the extraction, the crude M was slowly added to the hot water, stirred vigorously in the presence of a surfactant, then an organic solvent was added, and stirring was continued in the case of emulsification until the temperature reached 170 °C.

The surfactants are sodium dodecylbenzenesulfonate, sodium nonylbenzenesulfonate, ammonium dibutyldodecylbenzenesulfonate, an alkali metal salt of a sulfonated fatty alcohol, an alkali metal soap, and the like. When an ionic surfactant is used, after extraction, the first half of the solution is filtered and acidified to a pH of 3-4.

The aniline method is based on aniline, CS2 and S. Since CS2 is a flammable and explosive hazardous chemical, it is very inconvenient to use. The company has reported the use of aniline, N, N'-dimethylformamide and S. The production process of the synthesis accelerator M as a raw material. The reaction temperature is 200-300 ° C, the optimum reaction temperature is 225-275 ° C, the pressure is 3.45-4.83 MPa (gauge pressure), and the reaction time is about 12 h, but the yield of the method is relatively low, only 66%.













Inquiry