Continuous producing process of anti-aging agent 4020

Abstract

The invention discloses a continuous producing process of an anti-aging agent 4020, which has the advantages of stability and reliability in operation and high production efficiency. The process comprises the following steps of: adopting 4-aminodiphenylamine, methyl isobutyl ketone and hydrogen as raw materials; mutually preheating all raw materials by a preheater E101; enabling the preheated rawmaterials to enter a reactor; and carrying out catalytic hydrogenation reaction on the raw materials at a high pressure under the effect of a catalyst so as to obtain the anti-aging agent 4020, wherein the reactor is a gas-liquid-solid three-phase fixed bed hydrogenation reactor; the hydrogenation reaction is continuous operation carried out by using the gas-liquid-solid three-phase fixed bed hydrogenation reactor; the gas-liquid-solid three-phase fixed bed hydrogenation reactor comprises a main body container, a discharging opening, a completely discharging opening, a feed pre-distributor, an upper seal head, a lower seal head, an upper support, a lower support and a temperature measuring opening, wherein the feed pre-distributor is an exhaust pipe type pre-distributor which is mounted at the lower part of the main body container; the upper seal head is an elliptical seal head; and the lower seal head is also an elliptical seal head; and the temperature is 165-230 DEG C, the pressureis 5.5-6.0 MPa, the keto-amine ratio is 2-4:1 and the hydrogen-oil ratio is 2000-5000:1 during reaction.

Description

Technical field [0001] The invention relates to a production process of an antioxidant, and more specifically to a continuous production process of an antioxidant 4020. Background technique [0002] Anti-aging agent is an important part of rubber additives, and it has an irreplaceable effect on rubber's ozone resistance, oxidation resistance, heat resistance and flexural resistance. Among the many products of p-phenylenediamine series, the antioxidants 4010NA and 4020 are widely used all over the world. Anti-aging agent 4020 [N-(1,3-Dimethylbutyl)-N'-phenyl-p-phenylenediamine] belongs to p-phenylenediamine anti-aging agent with comprehensive protective effect, especially good durability, and is the current anti-aging agent It is widely used in rubber products such as tires and cables. The existing synthesis process is generally prepared by catalytic hydrogenation condensation of 4-aminodiphenylamine and methyl isobutyl ketone under high pressure. The fixed-bed hydrogenation re...

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Problems solved by technology

The heating steam of the preheater E101 is 3.5MPa superheated steam, and the following problems often occur in the production process: (1) When the catalyst is activated in one pass (activation temperature ≤ 150°C), due to the relatively high steam pressure and temperature, SP101 controls It is difficult to achieve self-control, and the temperature of TRC / 101 fluctuates greatly (±10°C), so it will easily cause over-temperature deactivation when the catalyst is activated, which also directly affects the life of the catalyst and the single-pass yield; (2) due to the steam pressure The fluctuation of TRC / 101 is relatively large, which causes the relatively large fluctuation of TRC / 101 temperature (±5°C), which directly affects the fluctuation of reaction temperature TRA101 in the reactor, and finally also affects the conversion rate (yield of product) of RT; (3 ) Due to relatively large fluctuations in steam pressure, cracks often appear in the expansion joint of the E101 outer pipe, resulting in shutdown

[0004] In addition, the catalysts used in the existing hydrogenation preparation process are generally copper-based catalysts, which also have the following disadvantages: in the early stage after the active period of the catalyst, the catalyst activity is very strong, the selectivity is poor, and excessive methyl isobutyl ketone reacts Methyl isobutyl carbinol is generated, resulting in a relatively large consumption of methyl isobutyl ketone

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