阅读说明：本技术 一种2,4-二硝基苯胺制备方法 (Preparation method of 2, 4-dinitroaniline ) 是由 阮煜翔 王凯 于 2019-10-29 设计创作，主要内容包括：本发明公开了一种2,4-二硝基苯胺制备方法,包括以下步骤：a、取料：称取2,4-二硝基氯苯、氨水、冷凝水三种原料；b、预热：将冷凝水加入反应装置内,升温至50～70℃；c、入料：将2,4-二硝基氯苯加入反应装置内,升温至80～90℃,控制压力至0.05～01MPa；d、胺化：将氨水缓慢滴加至反应装置内进行胺化反应,保温1～3h；e、离心：将步骤d中胺化生成的反应液离心洗涤、干燥得到2,4-二硝基苯胺。本发明具有反应速率快、反应效果好的优点。(The invention discloses a preparation method of 2, 4-dinitroaniline, which comprises the following steps: a. taking materials: weighing three raw materials of 2, 4-dinitrochlorobenzene, ammonia water and condensed water; b. preheating: adding condensed water into a reaction device, and heating to 50-70 ℃; c. feeding: adding 2, 4-dinitrochlorobenzene into a reaction device, heating to 80-90 ℃, and controlling the pressure to 0.05-01 MPa; d. amination: slowly dropwise adding ammonia water into the reaction device for amination reaction, and keeping the temperature for 1-3 h; e. centrifuging: and d, centrifugally washing and drying the reaction liquid generated in the amination step d to obtain the 2, 4-dinitroaniline. The method has the advantages of high reaction rate and good reaction effect.)

1. A preparation method of 2, 4-dinitroaniline is characterized by comprising the following steps: the method comprises the following steps:

a. taking materials: weighing three raw materials of 2, 4-dinitrochlorobenzene, ammonia water and condensed water;

b. preheating: adding condensed water into a reaction device, and heating to 50-70 ℃;

c. feeding: adding 2, 4-dinitrochlorobenzene into a reaction device, heating to 80-90 ℃, and controlling the pressure to 0.05-01 MPa;

d. amination: slowly dropwise adding ammonia water into the reaction device for amination reaction, and keeping the temperature for 1-3 h;

e. centrifuging: d, centrifugally washing and drying the reaction liquid generated in the step d to obtain 2, 4-dinitroaniline;

wherein, in step b reaction unit include reaction cylinder (1), reaction chamber (2) have in reaction cylinder (1), be equipped with inlet pipe (3) and ammonification pipe (4) that are linked together with reaction chamber (2) on reaction cylinder (1), reaction cylinder (1) bottom is equipped with discharging pipe (30), be connected with peristaltic pump (41) on ammonification pipe (4), reaction chamber (2) internal rotation is equipped with (mixing) shaft (5), be equipped with helical blade (6) along its length direction on (mixing) shaft (5), reaction cylinder (1) top is equipped with and is used for driving (mixing) shaft (5) pivoted stirring driving piece (7), be equipped with a plurality of ammonia extraction parts on reaction cylinder (1), the ammonia extraction part is arranged in with reaction chamber (2) gas suction of upper end in to the reaction liquid of reaction chamber (2) interior lower extreme, the ammonia extraction part is including running through ammonia extraction mouth (8) of locating reaction cylinder (1) upper end, Run through and locate ammonia outlet (9) of reaction cylinder (1) lower extreme and be used for connecting ammonia outlet (8) and ammonia outlet (9) lead to ammonia pipe (10), it takes out ammonia driving piece (11) to lead to be connected with on ammonia pipe (10), ammonia outlet (9) play is equipped with one-way circulation part.

2. The process according to claim 1, wherein the reaction mixture comprises a mixture of: the molar ratio of the 2, 4-dinitrobenzene chloride to the NH3 in the ammonia water is 1: 2.2 to 3.

3. The process according to claim 1, wherein the reaction mixture comprises a mixture of: the concentration of the ammonia water is 10-30 wt%.

4. The process according to claim 1, wherein the reaction mixture comprises a mixture of: one-way circulation part is including offering sliding chamber (12) in reaction cylinder (1) wall, sliding chamber (1) sliding connection has slider (13), slider (13) slide in sliding chamber (12) in order to open and close ammonia outlet (9), slider (13) are close to logical ammonia pipe (10) one side bottom and are equipped with pneumatic piece (14), be equipped with pneumatic chamber (15) that air feed movable block (14) slided from top to bottom in reaction cylinder (1) wall, pneumatic chamber (15) are linked together with ammonia outlet (9), sliding chamber (12) bottom is linked together through feed liquor pipe (16) with reaction chamber (2), slider (13) are made by the polypropylene materials, sliding chamber (12) top is equipped with sealing member.

5. The process according to claim 4, wherein the reaction mixture comprises: a water inlet cavity (17) is arranged in the sliding block (13), the lower end of the water inlet cavity (17) is communicated with a liquid inlet pipe (16), reaction liquid in the reaction cavity (2) can flow into the water inlet cavity (17) through the liquid inlet pipe (16), and the water inlet cavity (17) is provided with a plurality of reinforcing columns (18).

6. The process according to claim 4, wherein the reaction mixture comprises: sealing member is including locating sliding chamber (12) top and rather than sealed chamber (19) that are linked together, sealed chamber (19) top both sides are linked together through sealed passageway (20) respectively with sliding chamber (12), be equipped with in sealed chamber (19) rather than sealed complex sealed slider (21), sealed slider (21) lower extreme is equipped with contradicts complex convex part (22) with slider (13), sealed passageway (20) are close to sliding chamber (12) and serve and be equipped with rather than sealed complex sealing strip (23), sealing strip (23) are kept away from sliding chamber (12) one side and are equipped with support bar (231).

7. The process according to claim 1, wherein the reaction mixture comprises a mixture of: still be equipped with the grinding part that is used for refining 2, 4-dinitrochlorobenzene in reaction chamber (2), grinding part is including locating grinding casing (24) at reaction barrel (1) inner wall top, grinding casing (24) internal rotation is connected with grinding ball (25), grinding ball (25) fixed set up on (mixing) shaft (5), interval formation grinding clearance (26) between grinding ball (25) and grinding casing (24), grinding export (27) have been seted up to grinding casing (24) bottom.

8. The process according to claim 7, wherein the reaction mixture comprises: cooling chamber (27) have in grinding ball (25), cooling chamber (27) intussuseption is filled with the coolant liquid, be equipped with in grinding ball (25) and be used for the refrigerated condensation driving piece (28) to the coolant liquid, be connected through many spliced poles (29) between (mixing) shaft (5) and grinding ball (25) inner wall, grinding ball (25) and spliced pole (29) are made by iron brass or manganese brass.

9. The process according to claim 1, wherein the reaction mixture comprises a mixture of: the reaction tube is characterized in that an air pipe (31) is horizontally connected to the upper end of the reaction tube (1), two ends of the air pipe (31) are communicated with the reaction cavity (2), an air pumping driving piece (32) and a collecting box (33) are connected to the air pipe (31), a pressure controller (34) is arranged on the collecting box (33), and an ammonia gas detection device (35) used for detecting the concentration of ammonia gas in the reaction cavity (2) is further arranged outside the reaction tube (1).

10. The process according to claim 1, wherein the reaction mixture comprises a mixture of: (mixing) shaft (5) lower extreme is equipped with many scrapers (36) along its circumferential direction, scraper (36) are the arc setting, and its radian is unanimous with the bottom radian of reaction cylinder (1), (mixing) shaft (5) bottom is equipped with connecting rod (37), connecting rod (37) lower extreme stretches into to discharging pipe (30) in, connecting rod (37) lower extreme is equipped with rotating vane (38), driving rotating vane (38) when (mixing) shaft (5) rotate rotates in order to produce ascending whirl.

Technical Field

The invention relates to the technical field of chemical industry, in particular to a preparation method of 2, 4-dinitroaniline.

Background

2, 4-dinitroaniline is an intermediate of disperse dyes, neutral dyes, sulfur dyes and organic pigments, is used for producing dyes such as sulfur dark blue 3R, disperse red B, disperse violet 2R and the like, is also used for other organic synthesis, is used for producing pesticide dinitrogen powder and the like, and is used as a toner of printing ink and for preparing an antiseptic.

The reaction principle for preparing the 2, 4-dinitroaniline is as follows: the method comprises the steps of taking 2, 4-dinitrochlorobenzene and ammonia water as raw materials, adding the raw materials into a reaction device, and carrying out amination reaction to generate 2, 4-dinitroaniline, wherein the amination reaction belongs to bimolecular nucleophilic substitution reaction, firstly, an ammonia molecule with an unshared electron pair carries out nucleophilic attack on a carbon atom connected with a chlorine atom on an aromatic ring to obtain an intermediate addition product with polarity, and the intermediate addition product is quickly converted into a reaction product 2, 4-dinitroaniline and a byproduct ammonium chloride.

At present, the traditional high-temperature high-pressure method is mainly used for domestic production of 2, 4-dinitroaniline, the production safety risk is high, the energy consumption is high, the ammonia gas has strong volatility, the volatilized ammonia gas is accumulated at the top of a reaction device, once the ammonia gas concentration in the reaction device is 16-25% of the explosion limit, the explosion is easily caused when the ammonia gas concentration is too high, the volatilized ammonia gas cannot be effectively utilized, and the production cost is increased; and ammonia gas is toxic, and if the ammonia gas is discharged into the air after the reaction is finished, the ammonia gas pollutes the air, influences the body of an operator and even endangers the life of the operator.

Disclosure of Invention

The invention aims to solve the problems in the prior art and provide a method for preparing 2, 4-dinitroaniline.

The purpose of the invention can be realized by the following technical scheme: a preparation method of 2, 4-dinitroaniline comprises the following steps:

a. taking materials: weighing three raw materials of 2, 4-dinitrochlorobenzene, ammonia water and condensed water;

b. preheating: adding condensed water into a reaction device, and heating to 50-70 ℃;

c. feeding: adding 2, 4-dinitrochlorobenzene into a reaction device, heating to 80-90 ℃, and controlling the pressure to 0.05-01 MPa;

d. amination: slowly dropwise adding ammonia water into the reaction device for amination reaction, and keeping the temperature for 1-3 h;

e. centrifuging: and d, centrifugally washing and drying the reaction liquid generated in the amination step d to obtain the 2, 4-dinitroaniline.

Wherein, the reaction device in the step b comprises a reaction cylinder, a reaction cavity is arranged in the reaction cylinder, a feeding pipe and an ammonia adding pipe which are communicated with the reaction cavity are arranged on the reaction cylinder, a discharging pipe is arranged at the bottom of the reaction cylinder, a peristaltic pump is connected on the ammonia adding pipe, a stirring shaft is rotationally arranged in the reaction cavity, helical blades are arranged on the stirring shaft along the length direction of the stirring shaft, a stirring driving piece for driving the stirring shaft to rotate is arranged at the top of the reaction cylinder, a plurality of ammonia pumping parts are arranged on the reaction cylinder, the ammonia pumping parts are used for pumping gas at the upper end in the reaction cavity into reaction liquid at the lower end in the reaction cavity, each ammonia pumping part comprises an ammonia pumping port which penetrates through the upper end of the reaction cylinder, an ammonia discharging port which penetrates through the lower end of the reaction cylinder and an ammonia introducing pipe which is used for connecting the ammonia pumping port and, and a one-way circulation component is arranged at the outlet of the ammonia discharge port.

According to the invention, ammonia water is added in a dropwise manner, so that the reaction rate can be effectively controlled, high pressure is not required, a special solvent is not required, the reaction can be carried out only at the temperature of below 100 ℃ and under the pressure of 0.05-0.1 MPa, the yield is more than 99%, the production is safer, the appearance and the purity of the obtained product are improved, the product quality is excellent, and the cost is reduced; proper amount of bottom water is added into the reaction device, so that the solid content of the product can be reduced, the crystallization becomes thin, and the quality of the product is improved; the gas at the upper end in the reaction cavity is pumped into the reaction liquid at the lower end in the reaction cavity through the ammonia pumping part, and the ammonia in the gas is dissolved in the reaction liquid to react with the 2, 4-dinitrochlorobenzene when passing through the reaction liquid, so that the utilization of the ammonia is realized, the volatilization of the ammonia is reduced, the concentration of the ammonia in the reaction cavity is reduced, the explosion hazard is avoided, and the safety during the amination reaction is improved; the ammonia concentration in the reaction cavity is reduced through the ammonia pumping part, so that the gas can be directly discharged into the air after the reaction is finished, the body of an operator is not affected, the gas is not required to be filtered and purified, the production process is reduced, and the production cost is reduced; the gas is discharged into the reaction liquid, so that the reaction liquid can be in a rolling state, the reaction speed of the 2, 4-dinitrochlorobenzene and the ammonia water in the reaction liquid is improved, the reaction liquid can be stirred up and down, and the effect and the efficiency of amination reaction are ensured; through the setting of peristaltic pump for the mode of adding the aqueous ammonia is the dropwise add mode, is convenient for and comparatively accurate to the control of aqueous ammonia rate of addition, thereby effective control reaction rate.

The molar ratio of the 2, 4-dinitrobenzene chloride to the NH3 in the ammonia water is 1: 2.2 to 3.

The concentration of the ammonia water is 10-30 wt%.

The one-way circulation component comprises a sliding cavity arranged in the wall of the reaction cylinder, a sliding block is connected in the sliding cavity in a sliding mode and slides in the sliding cavity to open and close the ammonia discharging port, a pneumatic block is arranged at the bottom of one side, close to the ammonia discharging pipe, of the sliding block, a pneumatic cavity for the pneumatic block to slide up and down is arranged in the wall of the reaction cylinder, the pneumatic cavity is communicated with the ammonia discharging port, the bottom of the sliding cavity is communicated with the reaction cavity through a liquid inlet pipe, the sliding block is made of a polypropylene material, and a sealing component is arranged at the top of the sliding cavity.

A water inlet cavity is arranged in the sliding block, the lower end of the water inlet cavity is communicated with a liquid inlet pipe, reaction liquid in the reaction cavity can flow into the water inlet cavity through the liquid inlet pipe, and the water inlet cavity is provided with a plurality of reinforcing columns.

Sealing member is including locating the sealed chamber that slides the chamber top and be linked together rather than, sealed chamber top both sides are linked together through sealed passageway respectively with the chamber that slides, sealed intracavity is equipped with rather than sealed complex sealing slider, the sealing slider lower extreme is equipped with contradicts complex convex part with the slider, sealed passageway is close to and is equipped with rather than sealed complex sealing strip in the sliding chamber end, the sealing strip is kept away from sliding chamber one side and is equipped with the support bar.

The reaction chamber is also internally provided with a grinding component for refining the 2, 4-dinitrochlorobenzene, the grinding component comprises a grinding shell arranged at the top of the inner wall of the reaction cylinder, a grinding ball is rotatably connected in the grinding shell, the grinding ball is fixedly arranged on the stirring shaft, a grinding gap is formed between the grinding ball and the grinding shell at an interval, and a grinding outlet is formed at the bottom of the grinding shell.

The grinding ball is internally provided with a cooling cavity, the cooling cavity is filled with cooling liquid, a condensation driving piece used for refrigerating the cooling liquid is arranged in the grinding ball, the stirring shaft is connected with the inner wall of the grinding ball through a plurality of connecting columns, and the grinding ball and the connecting columns are made of iron brass or manganese brass.

The reaction device comprises a reaction barrel, and is characterized in that the upper end of the reaction barrel is horizontally connected with an air pipe, the two ends of the air pipe are communicated with a reaction cavity, the air pipe is connected with an air exhaust driving piece and a collecting box, the collecting box is provided with a pressure controller, and the reaction barrel is also externally provided with an ammonia gas detection device for detecting the concentration of ammonia gas in the reaction cavity.

The stirring shaft lower extreme is equipped with many scrapers along its circumference direction, the scraper is the arc setting, and its radian is unanimous with the bottom radian of reaction cylinder, the (mixing) shaft bottom is equipped with the connecting rod, the connecting rod lower extreme stretches into in the discharging tube, the connecting rod lower extreme is equipped with rotating vane, it rotates in order to produce ascending whirl to drive rotating vane when the (mixing) shaft rotates.

Compared with the prior art, the method has the advantages of high reaction rate and good reaction effect.

Drawings

FIG. 1 is a flow chart of the steps of the present invention.

FIG. 2 is a first schematic view of a reaction apparatus according to the present invention.

FIG. 3 is a sectional view of a reaction apparatus in the present invention.

Fig. 4 is a partial schematic view at a in fig. 3.

Fig. 5 is a partial schematic view at C in fig. 4.

Fig. 6 is a partial schematic view at B in fig. 3.

FIG. 7 is a second schematic view of the reaction apparatus of the present invention.

In the figure, 1, a reaction cylinder; 2. a reaction chamber; 3. a feed pipe; 4. an ammonia adding pipe; 41. a peristaltic pump; 5. a stirring shaft; 6. a helical blade; 7. a stirring driving member; 8. an ammonia extraction port; 9. an ammonia discharge port; 10. introducing an ammonia pipe; 11. an ammonia pumping drive; 12. a sliding cavity; 13. a slider; 14. a pneumatic block; 15. a pneumatic chamber; 16. a liquid inlet pipe; 17. a water inlet cavity; 18. a reinforcement column; 19. sealing the cavity; 20. sealing the channel; 21. sealing the sliding block; 22. a convex portion; 23. a sealing strip; 231. a supporting strip; 24. grinding the shell; 25. grinding balls; 26. grinding the gap; 27. a cooling chamber; 28. a condensing drive; 29. connecting columns; 30. a discharge pipe; 31. an air tube; 32. an air extraction driving member; 33. a collection box; 34. a pressure controller; 35. an ammonia gas detection device; 36. a scraper; 37. a connecting rod; 38. the blades are rotated.

Detailed Description

The following are specific embodiments of the present invention and are further described with reference to the drawings, but the present invention is not limited to these embodiments.