Anti-aging agent 6PPD synthesis method capable of reducing side reaction

Abstract

The invention belongs to the technical field of fine chemical engineering, and relates to a method for continuously synthesizing a rubber anti-aging agent 6PPD. The method comprises the following steps: synthesizing the anti-aging agent 6PPD on a fixed bed by adopting a noble metal catalyst, filling the noble metal catalyst into a fixed bed reaction device, filling and replacing the whole high-pressure reaction kettle system with nitrogen under the pressure of 0.1-0.5 MPa, heating after the replacement of the reaction system, and introducing hydrogen at the flow rate of 0.1-1L / min. 4-aminodiphenylamine, organic matters similar to the 4-aminodiphenylamine, methyl isobutyl ketone and acetone are used as raw materials, and a synthesis test for synthesizing the anti-aging agent 6PPD by adopting a noble metal catalyst is carried out. Compared with an existing noble metal kettle type hydrogenation process, the method has continuous operability, is simple and convenient to operate, avoids catalyst loss caused by filtration when a powder catalyst is adopted, and can reduce the production cost; compared with the existing copper-based catalyst, the selectivity of the catalyst is improved, so that an MIBC dehydrogenation device is not additionally arranged, the energy consumption is reduced, and the catalyst has superiority.

Description

technical field [0001] The invention belongs to the technical field of fine chemicals and relates to a method for continuously synthesizing anti-aging agent 6PPD. Background technique [0002] N-(1,3-Dimethylbutyl)-N-phenyl-p-phenylenediamine, the trade name is 6PPD. In addition to good antioxidant performance, this product also has anti-ozone, anti-flex cracking and Inhibit the effect of harmful metals such as copper and manganese, and can be widely used in the preparation of tires, tapes and many other industrial rubber products. It is one of the main varieties of p-phenylenediamine antioxidants. Therefore, as the main excellent variety commonly used in the rubber industry at home and abroad, 6PPD is the key direction for the research and development of rubber antioxidants. [0003] U.S. Patents US3366684A and US4043942A use RT and MIBK to synthesize rubber antioxidant 4020 in one step. The molar ratio of RT and MIBK is 1:4, 160-180 ° C, 4-5 MPa, and react for 4 hours. T...

AI Technical Summary

Problems solved by technology

[0005] Chinese Patent Application Publication No. CN1170711A discloses a method for synthesizing p-phenylenediamine rubber antioxidant in an autoclave. It also uses a one-step method to synthesize rubber antioxidant 4020 by condensation hydrogenation reaction at 2-10MPa and 180-250°C. Reduce the amount of MIBK (the molar ratio of RT times to MIBK is 1:1.05~1.1). Although the yield of the product is relatively good, too little amount of MIBK will cause the viscosity of the reaction solution to be particularly large and the fluidity to be poor, resulting in catalyst failure. very difficult to recycle

The catalyst used therein will lead to a small amount of copper remaining in the product 6PPD, which will cause harm to the quality of subsequent tire production, and the side reaction of ketone to alcohol is relatively severe, so it is necessary to add an MIBC dehydrogenation device, thereby increasing equipment investment, complex production process, and energy efficiency. higher consumption