阅读说明：本技术 采用生物改性催化剂制备对苯二胺类防老剂的方法 (Method for preparing p-phenylenediamine anti-aging agent by adopting biological modified catalyst ) 是由 张伟 王晓宁 管庆宝 黄伟 王培兰 顾炜菁 张蓉蓉 于 2018-06-25 设计创作，主要内容包括：一种对苯二胺类防老剂催化剂生物改性的方法,以4-氨基二苯胺和脂肪酮为原料,按比例加入生物改性剂,采用催化剂在塔式反应器或高压釜中缩合加氢生产相应的对苯二胺类防老剂。本发明无需在催化剂制备阶段进行改性,通过在反应液中添加一定比例的生物改性剂即可实现,有效提高催化剂的转化率和选择性,降低酮转醇副反应,减少生产废液,优化工艺条件下可不发生酮转醇副反应。实施例与对比例结果表明,通过添加生物改性剂,取得了良好的效果,特别是在抑制酮转醇副反应方面,固定床反应器的实施效果优于高压釜。(A process for biologically modifying the catalyst of p-phenylenediamine includes proportionally adding biological modifier to 4-aminodiphenylamine and aliphatic ketone, and condensing and hydrogenating the catalyst in tower reactor or high-pressure reactor to obtain the said catalyst. The method does not need modification in the catalyst preparation stage, can be realized by adding a certain proportion of biological modifier into the reaction liquid, effectively improves the conversion rate and selectivity of the catalyst, reduces the side reaction of ketone-alcohol conversion, reduces the production waste liquid, and can not generate the side reaction of ketone-alcohol conversion under the optimized process conditions. The results of the examples and the comparative examples show that the addition of the biological modifier achieves good effects, and particularly, the implementation effect of the fixed bed reactor is better than that of an autoclave in the aspect of inhibiting the side reaction of ketone-alcohol conversion.)

1. A method for preparing p-phenylenediamine anti-aging agents by using a biological modified catalyst is characterized in that 4-aminodiphenylamine and aliphatic ketone are used as raw materials, the biological modified agent is added in proportion, and the catalyst is used for condensation hydrogenation in a tower reactor or a reaction kettle to produce the corresponding p-phenylenediamine anti-aging agents, wherein the method comprises the following steps:

(1) preparing 4-aminodiphenylamine and aliphatic ketone into a solution, uniformly mixing, adding a biological modifier into the mixed solution, and uniformly mixing;

(2) adding the mixed raw materials into a fixed bed reactor or a reaction kettle which is assembled with a catalyst in advance, and carrying out condensation hydrogenation reaction;

(3) and (3) distilling the condensation hydrogenation reaction liquid under reduced pressure until no fraction is extracted, wherein the obtained product is the corresponding p-phenylenediamine anti-aging agent.

2. The method of claim 1, wherein the biological modifier is an organic compound containing carbon-sulfur bonds, and is selected from one or more of thiol, thioether, thiophenol, disulfide, polysulfide, cyclic sulfur compound, isothionate compound, sulfur-containing amino acid, alkali metal sulfide, hydrogen sulfide, ammonium sulfide, and sulfurous acid.

3. The method of claim 2, wherein the biological modifier is one or a combination of sulfur-containing amino acids.

4. The method according to claim 1, characterized in that the amount of the biological modifier added is 0.1 ~ 10% o by mass of 4-aminodiphenylamine.

5. The method according to claim 1 or 4, characterized in that the amount of the biological modifier added is 0.5 ~ 5% o by mass of 4-aminodiphenylamine.

6. The method of claim 1, wherein the catalyst is a copper catalyst, a nickel catalyst, a platinum catalyst, or a palladium catalyst.

7. The method according to claim 1 or 6, characterized in that the catalyst carrier is one or more of alumina, silica and activated carbon.

8. The method according to claim 1, wherein the biological modification method is applied to a reaction system for synthesizing the corresponding p-phenylenediamine anti-aging agent by using 4-aminodiphenylamine and aliphatic ketone as raw materials and adopting a reductive amination method.

9. The method of claim 8, which is used for a fixed bed reactor for continuous condensation hydrogenation.

10. The method of claim 8, wherein the method is used for batch condensation hydrogenation in an autoclave reactor.

Technical Field

The invention belongs to the field of organic chemistry, and relates to a method for biologically modifying a p-phenylenediamine anti-aging agent catalyst. Specifically, the invention relates to a method for improving the conversion rate and selectivity of a p-phenylenediamine anti-aging agent catalyst and reducing a side reaction of ketone-alcohol conversion.

Background

At present, the supply and demand of the rubber auxiliary agent in the world are basically stable, the annual average growth rate is about 4 ~ 5%, wherein the growth rate of developed countries and regions in Europe and America is about 1 ~ 2%, and the growth rate of Asia regions is as high as 8 ~ 10%.

The production principle of p-phenylenediamine antioxidants is similar, for example, the antioxidants 6PPD, IPPD, 7PPD, 8PPD and the like are generally used, 4-aminodiphenylamine (4-ADPA) and corresponding aliphatic ketone and hydrogen are used as raw materials, and condensation hydrogenation is carried out to produce the p-phenylenediamine antioxidants, at present, the p-phenylenediamine antioxidants account for the largest proportion is the antioxidants 6PPD, and the p-phenylenediamine antioxidants have the characteristics of high efficiency, low toxicity and balanced anti-aging comprehensive performance.

Chinese patent CN 1170711A discloses an autoclave synthesis process for p-phenylenediamine rubber antioxidants, which comprises the steps of using RT base and MIBK as raw materials, synthesizing 6PPD antioxidant through condensation hydrogenation at 2 ~ 10MPa and 180 ~ 250 ℃, wherein the molar ratio of the RT base to the MIBK is 1:1.05 ~ 1.1.1, the product yield is high, but the MIBK dosage is too small, the fluidity of a reaction liquid is poor, the recovery of a catalyst is very difficult, the side reaction of ketone-alcohol conversion in the reaction process is severe, the ratio of ketone-alcohol after the reaction is about 7:1, and the production waste liquid is more.

Chinese patent CN102626631A discloses a preparation method of a catalyst for synthesizing p-phenylenediamine antioxidants, the main components of the catalyst are copper, zinc and aluminum, the catalyst is prepared by adopting a coprecipitation method, when the catalyst is used for synthesizing the p-phenylenediamine antioxidants, the content of 6PPD is lower than 95% within 100h in the initial reaction period, and the time for the content of 6PPD to reach more than 95% in industrial use is more than 15 days. Patent introduction describes that the content of aliphatic ketone reaches 80% or more in 15 days, which indicates that the side reaction of ketone-alcohol conversion is severe in the initial stage of the reaction and produces a large amount of waste liquid.

According to the invention, the biological modifier is added into the reaction liquid in a certain proportion, so that the selectivity of the catalyst is improved, and the side reaction of ketone-alcohol conversion is effectively reduced or basically no side reaction occurs.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a method for improving the selectivity of a p-phenylenediamine catalyst, and mainly solves the problems of higher activity and severe side reaction in the initial reaction stage of the existing catalyst.

The technical scheme adopted by the invention is as follows: 4-aminodiphenylamine and aliphatic ketone are used as raw materials, a biological modifier is added according to a certain proportion, and a catalyst is adopted to produce the corresponding p-phenylenediamine anti-aging agent through condensation hydrogenation in a tower reactor or a reaction kettle. The method comprises the following steps:

(1) preparing 4-aminodiphenylamine and aliphatic ketone into a solution according to a certain molar ratio, and uniformly mixing. Then adding a certain proportion of biological modifier into the mixed solution, and uniformly mixing.

(2) Adding the mixed raw materials into a fixed bed reactor or a reaction kettle which is assembled with a catalyst in advance, and carrying out condensation hydrogenation reaction at a certain temperature and pressure.

(3) And (3) distilling the condensation hydrogenation reaction liquid under reduced pressure until no fraction is extracted, wherein the obtained product is the corresponding p-phenylenediamine anti-aging agent.

Further, the aliphatic ketone includes, but is not limited to, acetone, 4-methyl-2-pentanone, 5-methyl-2-hexanone, 2-octanone.

Further, the biological modifier is an organic compound containing carbon-sulfur bonds, and comprises one or more of mercaptan, thioether, thiophenol, disulfide, polysulfide, cyclic sulfur compounds, isothionate compounds, sulfur-containing amino acids, alkali metal sulfides, hydrogen sulfide, ammonium sulfide, and sulfurous acid.

Further, the biological modifier is preferably sulfur-containing amino acid, specifically one or a combination of more of methionine, cysteine and cystine.

Furthermore, the addition amount of the biological modifier is 0.1 ~ 10 per mill, preferably 0.5 ~ 5 per mill of the RT mass.

Further, the catalyst includes, but is not limited to, copper catalyst, nickel catalyst, platinum catalyst, palladium catalyst.

Further, the catalyst carrier is one or more of alumina, silica and activated carbon.

Further, the catalyst may be a powdery catalyst used in an autoclave reactor or a molded pellet catalyst used in a fixed bed reaction.

Further, the reaction temperature is 90 ~ 300 ℃, preferably 110 ~ 160 ℃.

Further, the reaction pressure is 1.0 ~ 4.5.5 MPa, preferably 1.5 ~ 2.5.5 MPa.

Further, the molar ratio of the raw material 4-aminodiphenylamine to the aliphatic ketone is 1:1.02 ~ 1:5.5, the autoclave reactor is preferably 1:1.05 ~ 2.0.0, and the fixed bed reactor is preferably 1:2.0 ~ 4.5.5.

The invention has the following beneficial effects: compared with the existing industrial production method, the method can effectively improve the selectivity of the catalyst, reduce side reactions, reduce production waste liquid, avoid the side reaction of ketone-alcohol conversion under optimized process conditions, and avoid dehydrogenation cost and energy consumption.

Detailed Description

The present invention will be described in detail with reference to specific examples. It should be noted that these examples are not intended to limit the scope of the present invention, which is defined by the appended claims.