Production process of rubber vulcanizing promoter DM

Abstract

The invention relates to the technical field of producing rubber promoters, in particular to a production process of a rubber vulcanizing promoter DM. The production process includes following steps: (1), adding an M sodium salt solution and sodium nitrite into a mixing kettle, and fully stirring and mixing; (2), sequentially feeding materials in the mixing kettle into at least a group of oxidizing kettles, heating and starting a fan and an ejector, dropwise adding dilute sulfuric acid, and continuing blowing air and stirring till an oxidizing end point after stopping dropwise adding the dilute sulfuric acid; (3), filtering the materials in the oxidizing kettles, enabling the same to enter a transit tank, controlling the transit tank to maintain a certain liquid level to deliver the materials for continuous water washing and dewatering, and granulating or drying the dewatered materials to obtain the DM finished product. By using the production process, production time is shortened greatly, manpower and materials are saved, production of a promoter M and production of the promoter DM are linked, zero emission of waste gas is realized, production continuity is high, and continuous production is realized.

Description

(1) Technical field [0001] The invention relates to the technical field of rubber accelerator production, in particular to a production process of a rubber vulcanization accelerator DM. (2) Background technology [0002] Rubber accelerator DM, chemical name 2,2'-dibenzothiazole disulfide, is a light yellow crystal, slightly toxic, odorless, slightly bitter, and is a widely used general-purpose thiazole accelerator. A very important drug synthesis intermediate. As a general-purpose vulcanization accelerator for natural rubber, synthetic rubber, and reclaimed rubber, it can vulcanize rubber quickly in the general temperature range, and the vulcanization curve is relatively flat. DM itself is easy to disperse in the rubber compound and does not pollute. Its vulcanization critical temperature Higher (130°C), the activity is enhanced when the temperature is above 140°C, there is a significant aftereffect, and the operation is safe. Vulcanized rubber has excellent physical and m...

AI Technical Summary

Problems solved by technology

The traditional production method of accelerator M is to use aniline, sulfur, and carbon disulfide as raw materials, react under high pressure to obtain crude M, and the crude M is usually refined by acid-base method: that is, the crude M reacts with alkali to form M sodium salt, and the resin is extracted with toluene , the filtered filtrate is adjusted with dilute sulfuric acid to adjust the PH value to further remove the resin, and then neutralize and dehydrate. The two processes of neutralization and dehydration will take 5h~7h, which wastes a lot of manpower, material resources and equipment energy consumption.

Moreover, the finished or semi-finished products of M are solid raw materials, which will cause relatively large dust during use, which will pollute the production site environment, which is not conducive to personnel health and on-site management. It is difficult to protect the M feeding port, and there is a large quality hidden danger

[0005] 2. A large amount of harmful gas is produced in the production process, which is discharged into the environment and causes pollution

The process of producing DM by sodium nitrite method is actually a heterogeneous chemical catalytic reaction in its oxidation reaction. In this reaction, the nitrous acid generated by the reaction of dilute sulfuric acid and sodium nitrite or the nitrogen dioxide or nitrogen dioxide produced by the decomposition of nitrous acid Nitrogen oxide acts as a catalyst, but in the traditional process, the nitrogen monoxide and nitrogen dioxide produced by the oxidation reaction are directly emptied, causing serious air pollution, reducing the utilization rate of the catalyst, prolonging the reaction time, increasing Increased production costs, and forced the use of more sodium nitrite and sulfuric acid in production, thereby further generating more waste gas and salty wastewater, which caused difficulties for subsequent treatment

[0006] 3. Intermittent production, from feeding, oxidation, water washing and dehydration, to granulation or drying process, all are intermittent operations, with low production efficiency, frequent start and stop of equipment, and poor quality uniformity

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