Preparation method of 2-mercaptobenzothiazole

Abstract

The invention discloses a preparation method of 2-mercaptobenzothiazole. The preparation method comprises the following steps of: preparing a sulfur dissolving solution in advance; preparing materials, namely adding aniline into a synthesis reactor, then adding the sulfur dissolving solution, and finally adding aniline and raising the temperature; performing a reaction for 2.5 hours to generate a 2-mercaptobenzothiazole solution under the condition that the temperature is stabilized between 200 and 210 DEG C and the pressure is controlled between 80 and 81Mpa; performing exhausting; discharging materials, namely adopting an upper discharging mode, opening a steam valve, pressing out the 2-mercaptobenzothiazole solution, discharging the materials from a discharge pipe penetrating through the top of the reactor, and pressing the materials into a real-time stirring alkali dissolving tank in which caustic soda is introduced in advance; performing alkali dissolution; performing changing; performing neutralization; and treating resin. According to the preparation method, the 2-mercaptobenzothiazole is produced by adopting a high-pressure one-step method, the sulfur dissolving solution enters a reaction kettle to react with aniline, and the 2-mercaptobenzothiazole is synthesized by one step under a high pressure. The preparation method is simple and safe in production, good in product quality, and excellent in technical and economic index, and basically has no discharged waste, so that the preparation method is relatively wide in application.

Description

technical field [0001] The invention relates to the technical field of fine chemical production, in particular to a preparation method of 2-mercaptobenzothiazole. Background technique [0002] 2-Mercaptobenzothiazole, known as "M" in the industry, has the characteristics of fast vulcanization acceleration, low vulcanization flatness, and no early vulcanization during mixing. It is widely used in the rubber processing industry. It is a natural rubber and High-efficiency rubber vulcanization accelerator essential for synthetic rubber. At present, the commonly used method in industrial production is the o-nitrochlorobenzene method: [0003] Sodium polysulfide, o-nitrobenzene chloride and carbon disulfide are used to condense M sodium salt at a temperature of 110-130°C and a pressure of 3.5 atm. After purification, drying, crushing, screening, etc., the finished product M is obtained. This low-temperature and low-pressure method M process is produced by two domestic organic f...

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Problems solved by technology

[0004] The present invention intends to provide a preparation method of 2-mercaptobenzothiazole, so as to solve the problems of low-temperature and low-pressure production of M in the prior art with poor quality and many wastes

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