阅读说明：本技术 连续合成n-2-乙基己基-n`-苯基对苯二胺的方法 (Method for continuously synthesizing N-2-ethylhexyl-N' -phenyl-p-phenylenediamine ) 是由 任磊 陶建青 金刚 李珊 于 2018-09-06 设计创作，主要内容包括：本发明提供一种防老剂,即N-2-乙基己基-N’-苯基对苯二胺的合成方法。以2-乙基己醛、4-氨基二苯胺为基本原料,在催化剂存在条件下,在固定床中连续反应得到含N-2-乙基己基-N’-苯基对苯二胺的混合物,经过纯化处理,得到N-2-乙基己基-N’-苯基对苯二胺。本发明利用固定床连续生产N-2-乙基己基-N’-苯基对苯二胺,与现有技术中提到的釜式间歇反应比较,适合推广工业应用。(The invention provides a synthesis method of an anti-aging agent, namely N-2-ethylhexyl-N' -phenyl-p-phenylenediamine. 2-ethylhexanal and 4-aminodiphenylamine are used as basic raw materials, the mixture containing N-2-ethylhexyl-N '-phenyl-p-phenylenediamine is obtained by continuous reaction in a fixed bed in the presence of a catalyst, and the N-2-ethylhexyl-N' -phenyl-p-phenylenediamine is obtained by purification treatment. The method utilizes the fixed bed to continuously produce the N-2-ethylhexyl-N' -phenyl-p-phenylenediamine, and is suitable for popularization and industrial application compared with the kettle type batch reaction in the prior art.)

1. The continuous synthesis process of N-2-ethylhexyl-N ' -phenyl p-phenylenediamine features that 2-ethylhexanal and 4-aminodiphenylamine as basic material are reacted continuously in fixed bed in the presence of catalyst to obtain N-2-ethylhexyl-N ' -phenyl p-phenylenediamine mixture, which is purified to obtain N-2-ethylhexyl-N ' -phenyl p-phenylenediamine.

2. The process as claimed in claim 1, wherein the catalyst used is a copper-based catalyst or a Pt/C catalyst.

3. The method as set forth in claim 2, wherein the copper-based catalyst comprises CuO, ZnO, Al₂O₃The components are respectively 30-40 percent, 55-65 percent and 1-10 percent by mass.

4. The method as set forth in claim 3, wherein the catalyst is in an oxidation state before use, and is used by reduction activation at a reduction temperature ranging from 160 to 220 ℃ under N₂、H₂H in the mixed gas₂The proportion of (A) is adjusted from 1 to 100 percent, finally maintained at 100 percent, and maintained at 220 ℃ for 4 to 8 hours.

5. The method of claim 1The method is characterized in that the molar ratio of 2-ethylhexanal to 4-aminodiphenylamine is 2-5: 1, and the space velocity of the reaction liquid is 0.1-0.2 h^-1Controlling the temperature of the reactor to be 80-120 ℃, controlling the reaction pressure to be 0.8-1.2 MPa, and controlling the tail gas to be 50-150 mL/min; the reaction liquid consists of a mixture of N-2-ethylhexyl-N' -phenyl-p-phenylenediamine, 2-ethylhexanal, 2-ethylhexanol, water and 4-aminodiphenylamine.

6. The method according to claim 1, wherein the purification method of the reaction solution is distillation under reduced pressure, the reduced pressure is-0.09 to-0.10 MPa, the distillation time is 1 to 3 hours, the temperature of the distillation liquid phase is 60 to 120 ℃, and the temperature of the gas phase is 48 to 115 ℃.

7. The method as claimed in claim 2, wherein the Pt/C catalyst has a Pt content of 0.1% to 0.5%, and the activated carbon is columnar coconut shell activated carbon, has a specific surface area of more than 1000, and has a diameter of 2-4 mm.

8. The method as set forth in claim 7, wherein said catalyst is dried before use, N₂The reactor was purged with oxygen and N was added₂And (3) carrying out temperature programming, wherein the temperature programming range is 100-120 ℃, and the time is 2-4 hours.

9. The method as set forth in claim 1, wherein the molar ratio of 2-ethylhexanal to 4-aminodiphenylamine is 2-4: 1, and the space velocity of the reaction liquid is 0.1-0.2 h^-1Controlling the temperature of the reactor to be 60-100 ℃, controlling the reaction pressure to be 0.8-1.2 MPa, and controlling the tail gas to be 50-150 mL/min; the reaction liquid consists of a mixture of N-2-ethylhexyl-N' -phenyl-p-phenylenediamine, 2-ethylhexanal, water and 4-aminodiphenylamine.

10. The method according to claim 1, wherein the reaction solution is purified by distillation under reduced pressure of-0.09 to-0.10 MPa for 1 to 3 hours at a liquid phase temperature of 60 to 110 ℃ and a gas phase temperature of 48 to 100 ℃.

Technical Field

The invention relates to a synthesis method of an anti-aging agent, namely N-2-ethylhexyl-N' -phenyl-p-phenylenediamine.

Background

The antioxidant S789 is used as a universal antioxidant for Natural Rubber (NR) and synthetic rubber, and has good protection effects on ozone and flex cracking. It is suitable for rubber products bearing stress and weather aging dynamically and statically, such as automobile tires, door and window sealing strips, electric wires, cables, rubber tubes, adhesive tapes and other industrial rubber products.

The structural formula of the anti-aging agent, namely N-sec-octyl-N' -phenyl p-phenylenediamine is shown as follows:

the research and application of the antioxidant S789 are rarely reported. In recent years, the russian khimorm company has studied and developed the anti-aging agent S789, and has been popularized and applied in petrochemical enterprises such as togliatti (sibur), sterlithaak, and the like.

At present, the synthesis of N-2-ethylhexyl-N' -phenyl-p-phenylenediamine mainly depends on the synthesis of related fatty alcohol (mainly isooctanol (2-ethylhexanol)) and RT base (4-aminodiphenylamine) under strong alkali, high temperature and high pressure conditions, such as Russian patents RU2417981C1, RU2293077C, RU2362767, RU2406720C1, RU2010146340A and the like. The technical solutions described in these patents all have the disadvantages of complex process (such as high temperature and high pressure and special catalyst), high requirement for equipment, high production cost, etc.

In the domestic method for synthesizing N-2-ethylhexyl-N '-phenyl-p-phenylenediamine in Jiangsu san ao patent CN106431932A, 2-ethyl-2-hexenal is prepared from N-butyraldehyde, and then the 2-ethyl-2-hexenal reacts with RT base under the action of a catalyst to prepare the compound N-2-ethylhexyl-N' -phenyl-p-phenylenediamine. Specifically, the 2-ethyl-2-hexenal and RT base reaction step is that one or more polar solvents selected from methanol, toluene, ethanol, n-butanol and dichloromethane are added into a reaction system, and the selected catalyst is one or more selected from copper catalysts, palladium-carbon catalysts, nickel catalysts, platinum-carbon catalysts and reduced iron powder.

Disclosure of Invention

The invention aims to provide a method for synthesizing an anti-aging agent, namely N-2-ethylhexyl-N' -phenyl-p-phenylenediamine.

The synthesis process of N-2-ethylhexyl-N ' -phenyl p-phenylenediamine features that 2-ethylhexanal and 4-aminodiphenylamine as basic material are reacted continuously in fixed bed in the presence of catalyst to obtain N-2-ethylhexyl-N ' -phenyl p-phenylenediamine mixture, which is purified to obtain N-2-ethylhexyl-N ' -phenyl p-phenylenediamine.

In order to achieve the purposes, the invention adopts the main technical scheme that: 2-ethylhexanal and 4-aminodiphenylamine are used as basic raw materials, and are continuously reacted in a fixed bed in the presence of a catalyst to obtain a mixture containing N-2-ethylhexyl-N '-phenyl-p-phenylenediamine, and the mixture is purified to obtain the N-2-ethylhexyl-N' -phenyl-p-phenylenediamine.

Typically, the catalyst used is a copper based catalyst or a Pt/C catalyst.

The synthesis process of N-2-ethylhexyl-N' -phenyl p-phenylenediamine includes the following steps:

first step, catalyst activation:

(1) if the catalyst is a copper-based catalyst, it is used in an oxidation state before use and needs to be subjected to reduction activation.

The reduction activation is carried out by loading catalyst and N in a fixed bed reactor₂The reactor was purged with oxygen and N was added₂，H₂Mixing the gases, and raising the temperature by program. In the reaction process, the gas proportion is adjusted along with the temperature in the reactor, and H is gradually increased under the steady state of the temperature₂The ratio, temperature no longer changed and activation was complete. Introduction of N₂And protecting for later use.

The selected catalyst is characterized in that the copper catalyst consists of CuO, ZnO and Al₂O₃The compositions by weight percentage are respectively 30-40%, 55-65% and 1-10%. The temperature range of the programmed temperature is 160-220 ℃, N₂、H₂H in the mixed gas₂The proportion of (A) is adjusted from 1 to 100 percent, and finally maintained at 100 percent.

(2) If the catalyst selected is a Pt/C catalyst, it is in a reduced state before use and is dried.

The drying treatment is carried out by loading catalyst and N in a fixed bed reactor₂The reactor was purged with oxygen and N was added₂And (4) temperature programming. The temperature range of the programmed heating is 100-120 ℃, and the time is 2-4 hours.

The selected catalyst is characterized in that the catalyst consists of Pt and columnar living coconut shell carbon. The content of Pt is 0.1-0.5%, the specific surface area of the coconut shell activated carbon is more than 1000, and the diameter is 2-4 mm.

Secondly, fixed bed synthesis of N-2-ethylhexyl-N' -phenyl-p-phenylenediamine:

2-ethylhexanal and 4-aminodiphenylamine are used as basic raw materials, and the mixture containing N-2-ethylhexyl-N' -phenyl-p-phenylenediamine is obtained through continuous condensation hydrogenation reaction in a fixed bed in the presence of a catalyst.

(1) Catalytic reaction of copper catalyst

The mol ratio of 2-ethylhexanal to 4-aminodiphenylamine is 2-5: 1, and the space velocity of the reaction liquid is 0.1-0.2 h^-1The temperature of the reactor is controlled to be 80-120 ℃, the reaction pressure is 0.8-1.2 MPa, and the tail gas is 50-150 mL/min.

(2) Pt/C catalyst catalyzed reaction

The mol ratio of 2-ethylhexanal to 4-aminodiphenylamine is 2-4: 1, and the space velocity of the reaction liquid is 0.1-0.2 h^-1The temperature of the reactor is controlled to be 60-100 ℃, the reaction pressure is 0.8-1.2 MPa, and the tail gas is 50-150 mL/min.

Thirdly, purifying a reaction product mixture:

(1) copper catalyst catalytic reaction liquid

The mixture containing N-2-ethylhexyl-N '-phenyl-p-phenylenediamine is a mixture of N-2-ethylhexyl-N' -phenyl-p-phenylenediamine, 2-ethylhexanal, 2-ethylhexanol, water and 4-aminodiphenylamine.

The purification method is reduced pressure distillation. The reduced pressure condition is-0.09 to-0.10 MPa, the distillation time is 1 to 3 hours, the temperature of a distillation liquid phase is 60 to 120 ℃, and the temperature of a gas phase is 48 to 115 ℃.

(2) Pt/C catalyst catalytic reaction liquid

The mixture containing N-2-ethylhexyl-N '-phenyl-p-phenylenediamine is a mixture of N-2-ethylhexyl-N' -phenyl-p-phenylenediamine, 2-ethylhexanal, water and 4-aminodiphenylamine.

The purification method is reduced pressure distillation. The reduced pressure condition is-0.09 to-0.10 MPa, the distillation time is 1 to 3 hours, the temperature of a distillation liquid phase is 60 to 110 ℃, and the temperature of a gas phase is 48 to 100 ℃.

The invention has the beneficial effects that: the fixed bed is utilized to continuously produce the N-2-ethylhexyl-N' -phenyl-p-phenylenediamine, and compared with the kettle type batch reaction mentioned in the prior patent, the method is suitable for popularization and industrial application.

Detailed Description

The technical solution of the present invention is further described below with reference to examples, and the scope of the present invention is not limited to the following specific embodiments.