Process and equipment for purifying paraphthaloyl chloride

Abstract

The invention belongs to the technical field of organic matter purification, and particularly relates to a process for purifying paraphthaloyl chloride. The process specifically comprises the following steps: with a crude paraphthaloyl chloride product as a raw material, controlling a cooling rate to realize curing of a product so as to realize preliminary purification, performing sweating operation at 80-82 DEG C for further purification, and finally carrying out heating to 90-105 DEG C for melting to obtain the high-purity paraphthaloyl chloride. The process is mild in operation condition, high in system operation safety coefficient and safe and stable in production, the purity of the purified product is as high as 99.98% or above, and the process is suitable for industrial production.

Description

Technical field [0001] The invention belongs to the technical field of organic matter purification, and specifically relates to a process method and equipment for purifying terephthaloyl chloride. Background technique [0002] Terephthaloyl chloride is a monomer for the synthesis of special fibers. It can be used as a reinforcing agent for aramid and nylon. It is also a common raw material for organic synthetic polymers such as polyamide and polyester. In 2006, the chemical fiber investment early warning system of China Chemical Fiber Industry Association listed aramid 1414 fiber as a double green light project. With the rapid development of my country’s aerospace industry, there will be greater breakthroughs in the application of aramid materials; and modern defense, fire protection, chemical industry, metallurgy, hydropower, geology and mining, nuclear industry and other industries have heat insulation, ventilation, flame retardancy The demand for special materials that are res...

AI Technical Summary

Problems solved by technology

[0003] At present, the purification of terephthaloyl chloride at home and abroad is mainly the separation of the product from excess thionyl chloride and the catalyst. Since there is a large difference in boiling point between the three, separation and purification can be easily achieved through rectification. The disadvantage is that the product has a high boiling point. In the early stage of rectification and purification, the thionyl chloride present in the system can react with the product under the conditions of high temperature (110-130 ° C) and the presence of a catalyst to generate a high boiling impurity. However, high-boiler impurities are easily entrained during the distillation process, thereby increasing the difficulty of separation, reducing product purity, increasing production costs, and accompanied by a certain amount of solid waste that is difficult to handle, and thionyl chloride is easy to generate di Sub-environmental pollution

[0007] When the preparation process uses a solid-phase catalyst, and the melt crystallization method is used for post-treatment, it is difficult to remove solid catalyst impurities during the process of cooling down and solidifying and heating up to sweat, and the final temperature of sweating is too low. According to the patent, the purity of the purified product is 99.9%, which limits its wide application in special fiber synthesis

[0008] Patent CN 104225952 discloses a high-purity isophthaloyl chloride purification device, which adopts layered crystallization without a stirring device, and is not easy to expose the impurities wrapped in the crude product. In addition, its cooling rate is 0.001-0.05°C / min , the heating rate is 0.001-0.035°C / min, it is difficult to control the off-line, high requirements for equipment and high production cost

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