Prospect of the hottest p-dichlorobenzene

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Prospect of p-dichlorobenzene

p-dichlorobenzene is an important organic chemical raw material, which is mainly used as moth proofing agent, mildew proofing agent and deodorizer. It can also be used in Engineering Plastics Polyphenylene Sulfide, synthetic pesticides, pharmaceuticals, dyes and synthetic special fibers

the foreign p-dichlorobenzene market is relatively mature. The annual production capacity of the United States, Western Europe and Japan is about 140000 tons, and the consumption also basically maintains this level. Although the expansion of production capacity has been limited in recent years, the demand for dichlorobenzene in these regions has shown an upward trend, resulting in an increase in imports

the development and application of p-dichlorobenzene in China is relatively late. Before the 1980s, p-dichlorobenzene has been recycled by mixing the by-product of the production of chlorobenzene. The output is very small and the quality is poor, which affects the deep processing and application of p-dichlorobenzene. It was not until 1988 that Shandong introduced refining equipment and technology from abroad that the domestic production and application of p-dichlorobenzene began to develop rapidly. Through the joint efforts of domestic scientific research institutions and enterprises, digesting and absorbing foreign advanced technology, the technology of benzene directional chlorination to produce p-dichlorobenzene has been increasingly matched and improved. Four large-scale production units have been built, with an annual capacity of 15000 tons

at present, four sets of large-scale production units in China have their own characteristics. Shandong Dacheng pesticide Co., Ltd. and Handan Fuyang Chemical Group Co., Ltd. adopt kettle intermittent chlorination method. In this method, benzene reacts with chlorine in the presence of catalyst, and the generated crude chlorination liquid is washed with water and alkali to obtain fine chlorination liquid, which is sent to p-dichlorobenzene for separation. P-dichlorobenzene separation is a crystallization separation method of solid-liquid phase transition. Among them, Shandong Dacheng pesticide Co., Ltd. introduced Canadian crystallizer and carried out transformation; Handan Fuyang Chemical Group Co., Ltd. introduced Swiss Sulzer film crystallizer. Jinxi Chemical Group Co., Ltd. and Jiangsu Yangnong Chemical Group Co., Ltd. use continuous chlorination to produce p-dichlorobenzene, and the reaction is carried out in a loop reactor. However, Jinxi Chemical Co., Ltd. uses benzene as the starting material to produce chlorinated benzene and p-dichlorobenzene through directional chlorination

high purity p-dichlorobenzene can be used to prepare deodorants, moth proofing agents and mold proofing agents, and its derivatives are also widely used

deodorant, moth proofing agent and mold proofing agent are widely used in secondary plastics abroad. Chlorobenzene was initially used in deodorant, moth proofing agent and mold proofing agent. In the United States, p-dichlorobenzene is used as household deodorant and mothproof agent, accounting for about 32% of the total consumption of p-dichlorobenzene; in Western Europe, about 50% of p-dichlorobenzene is used as deodorant; in Japan, p-dichlorobenzene is used as household deodorant and mothproof agent, accounting for about 68%

the application of p-dichlorobenzene in deodorants, moth proofing agents and mold proofing agents in China started late. On the one hand, this is because the production of refined p-dichlorobenzene in China is still in the initial stage. On the other hand, the environmental protection problems of p-dichlorobenzene used as deodorant and moth repellent are still classified as follows: 1. To be solved. In order to meet the market demand and facilitate the development and application of p-dichlorobenzene, the relevant departments have worked out the p-dichlorobenzene industry quality standards together with the production enterprises, so that the product quality of p-dichlorobenzene has a basis for measurement. Judging from the current situation, the purity of dichlorobenzene products of some large tonnage production enterprises has reached more than 99.8%. In addition, efforts should be made to develop multi variety, multi model, serialized fungicides, moth proofing agents and deodorants for different occasions, so as to expand domestic demand and actively open up foreign markets. With a large population and booming economy, China has a wide range of deodorants, fungicides and moth proofing agents. It can be predicted that the consumption prospect of p-dichlorobenzene in this field is promising

synthesis of special engineering plastics polyphenylene sulfide resin another use of p-dichlorobenzene is the synthesis of polyphenylene sulfide resin. Polyphenylene sulfide resin is a high-performance special engineering plastic, which has excellent characteristics such as high temperature resistance, radiation resistance, ablation resistance, high toughness, high stability and so on. It is widely used in electronic and electrical, mechanical manufacturing, aviation, aerospace and other fields. After American enterprises introduced polyphenylene sulfide resin to the market in 1973, it received widespread attention. Due to patent protection, until the expiration of the patent protection period in 1985, six companies in Japan and Germany successively established polyphenylene sulfide resin production plants, which made polyphenylene sulfide resin develop rapidly and become a major variety of special engineering plastics. The research work of polyphenylene sulfide resin in China began in the early 1970s. The research units include Sichuan University, Tianjin Institute of synthetic materials, Guangzhou Institute of chemical industry, etc., and several pilot plants have also been built. However, due to large solvent consumption, high cost, poor product quality and other reasons, industrialization has not been realized, so domestic polyphenylene sulfide resin is basically dependent on imports

synthesis of 2,5-dichloronitrobenzene p-dichlorobenzene can also synthesize 2,5-dichloronitrobenzene, which is prepared by nitration of p-dichlorobenzene. 2,5-dichloronitrobenzene is mainly used in the production of ice dye. It is an intermediate of scarlet GG, red 3GL, red RL, etc. In addition, scientific research institutions have developed its new use as a nitrogen fertilizer synergist to improve rice yield. Nitrogen fertilizer is seriously lost in farmland due to the destruction of some microorganisms in the soil. In order to effectively use nitrogen fertilizer and promote crop yield, nitrogen fertilizer synergists need to be used. The toxicity test of relevant departments confirmed that it is one of the ten varieties of large-scale plastic market with the lowest toxicity among the known nitrogen fertilizer synergists

2,5-dichloronitrobenzene is also the raw material for the preparation of triclosin (2,4,4-trichloro-2-hydroxydiphenyl ether). 2,5-dichloronitrobenzene is etherified with 2,4-dichlorophenol, and then triclosin is obtained by reduction and hydrolysis. Triclosin is a new antibacterial agent with high efficiency, broad spectrum and safety. It has no irritation and allergic reaction to skin, and has high inhibitory effect on Gram-positive bacteria, Gram-negative bacteria, fungi, yeasts and viruses. It has excellent stability and compatibility, no unpleasant smell, less dosage and long-lasting effect. It is an environmental friendly antibacterial agent that attracts people's attention today. It is widely used in daily chemicals and medical and health disinfectants. The production and application of triclosan in China is still in its initial stage. Chengdu Seven Star Technology Co., Ltd., Sichuan Natural Gas Chemical Industry Research Institute, Zhejiang Huangyan East Asia Pharmaceutical and Chemical Co., Ltd. have successfully developed triclosan, and a small batch of products are available in the market. Compared with foreign production and application, China still lags far behind, and there are still many gaps, so its market potential is great

p-phenylenediamine, a raw material for the synthesis of aramid fiber, can be aminated with p-dichlorobenzene in the presence of catalyst to produce p-phenylenediamine, which is one of the important raw materials for the synthesis of special fiber aramid fiber. Aramid fiber is a new type of aromatic polyamide fiber, which has both the mechanical properties of inorganic fibers and the processing properties of organic fibers. Its density is close to that of polyester fiber, and its strength is 2 times that of polyester fiber, 3 times that of glass fiber, and 6 times that of steel wire. Its modulus is far greater than that of glass fiber and steel wire. In addition, it also has excellent heat and chemical resistance, dimensional stability, fatigue resistance Corrosion resistance and adhesion with rubber are outstanding. In addition to DuPont of the United States, the Netherlands and CIS also produce aramid fibers, such as Xiangxi laodi biological Co., Ltd., Hubei laolongdong Eucommia development company, Henan hengruiyuan Industrial Co., Ltd., Gansu runlin Eucommia development company, etc. Aramid fiber has broad application prospects in hoses, inflatable products, oil storage containers, protective clothing for automotive, petrochemical, aviation, agriculture and other fields. China began to develop aramid fiber in the 1980s. In view of the excellent properties and special applications of aramid fiber, it can be expected that its development in China will continue to accelerate

p-dichlorobenzene has been produced and used abroad for more than 70 years, involving a wide range of applications. Due to the limitations of separation and refining methods, the application and development of p-dichlorobenzene are affected in China. Now, the production of high-purity p-dichlorobenzene in China has begun to take shape, the production technology has reached a certain level, and the product quality and price can compete with foreign products. However, at present, the equipment is under construction, which is due to the insufficient development of domestic downstream products. Therefore, the focus of domestic development of p-dichlorobenzene in the future should be to vigorously develop its derivatives. At the same time, due to the rapid growth of foreign demand, we can actively explore the international market, expand exports, and promote the production and consumption of dichlorobenzene in China

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