Continuous flow process of azo polyether dye

Abstract

The invention discloses a continuous flow process of azo polyether dye, which comprises the following steps: (1) dissolving thiazole or benzothiazole diazo components in a sulfuric acid aqueous solution to prepare a fluid A, and dissolving a diazotizing agent in sulfuric acid or water to prepare a fluid B; and (2) respectively pumping the fluid A and the fluid B into a tubular reactor at respective constant rates through a plunger pump, maintaining a proper diazo reaction temperature, standing for a certain time, completely diazotizing, continuously flowing the generated diazo salt liquid into an aniline polyether solution, and immediately coupling until the coupling is complete, thereby obtaining a polyether dye solution. Through continuous flow diazotization of the azo polyether dye, rapid and complete diazotization at room temperature and instant coupling are realized, and the acid consumption for coupling is synchronously reduced; compared with a conventional batch process, the total reaction yield is increased by 10%; the process disclosed by the invention realizes improvement of safety and economical efficiency while pursuing to accord with a green chemistry principle, and has a great industrial application value.

Description

Technical Field

[0001] This invention relates to the field of fine chemical technology, specifically to a continuous flow process for azo polyether dyes. Background Technology

[0002]

[0003] In formula I, X = H or CH3;

[0004]

[0005] In Formula II, X = H or CH3; Y = H or CH3 or NO2 or CH3O; Z = H or CH3.

[0006] The thiazole structure shown in Formula I and the benzothiazole structure shown in Formula II are azo heterocyclic polyether dyes. They have excellent color fastness, bright colors, and high color intensity, as well as good hydrophilicity. They are widely used in various fields such as daily chemicals, polyurethane foam, stationery, and leather coloring.

[0007] Current technologies involve the synthesis or application of thiazole or benzothiazole dyes, but these processes are all batch reactions, involve wastewater with high acidity and high salt content, and result in low purity and yield, which greatly limits the application advantages of this type of dye in various fields.

[0008] In addition, existing conventional batch processes have low heat exchange efficiency for the diazotization unit reaction, which can easily lead to a surge in diazotization temperature due to the inability to remove reaction heat in time, posing a very serious safety hazard.

[0009] Therefore, there is an urgent need to improve the existing technology. Summary of the Invention

[0010] The technical problem to be solved by this invention is to overcome the technical defects of the prior art and provide a continuous flow process for azo polyether dyes. This invention achieves rapid and complete diazotization at room temperature and instantaneous coupling through continuous flow diazotization of azo polyether dyes, while simultaneously reducing the amount of acid used for coupling. Compared with conventional batch processes, the overall reaction yield is increased by 10%. This invention's process pursues compliance with green chemistry principles while also achieving a balance between safety and economy, possessing significant industrial application value.

[0011] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0012] A continuous flow process for an azo polyether dye includes the following steps:

[0013] (1) Dissolve the diazo component of formula I (thiazole) or formula II (benzothiazole) in an aqueous sulfuric acid solution to prepare fluid A, and dissolve the diazotizing agent in sulfuric acid or water to prepare fluid B;

[0014]

[0015] In formula I, X = H or CH3;

[0016]

[0017] In Formula II, X = H or CH3; Y = H or CH3, or NO2 or CH3O; Z = H or CH3;

[0018] (2) Fluid A and fluid B are pumped into the tubular reactor at constant rates by plunger pumps to maintain a suitable diazo reaction temperature. After a certain residence time, they are completely diazotized. The generated diazo salt solution is continuously flowed into the aniline polyether solution for immediate coupling until complete coupling, thus obtaining a polyether dye solution.

[0019] The chemical reaction formulas for the diazotization and coupling reactions involved in the above process are described below:

[0020] A: Diazo reaction formula for thiazole components:

[0021]

[0022] Coupling reaction formula for thiazole components:

[0023]

[0024] B: Diazo reaction formula for benzothiazole components:

[0025]

[0026] Coupling reaction formula for benzothiazole components:

[0027]

[0028] Preferably, in step (1), the concentration of the sulfuric acid aqueous solution is 30% to 85%; wherein, if sodium nitrite is used as the diazotizing agent, the concentration of the sulfuric acid aqueous solution is 30% to 35%; if nitrosylsulfuric acid is used as the diazotizing agent, the concentration of the sulfuric acid aqueous solution is 65% to 85%.

[0029] Preferably, in step (1), the diazotizing agent is sodium nitrite or nitrosylsulfuric acid; wherein, if it is a thiazole-based diazo component, the diazotizing agent is a 25% to 32% aqueous solution of sodium nitrite; if it is a benzothiazole-based diazo component, the diazotizing agent is a 35% to 42% nitrosylsulfuric acid.

[0030] Preferably, in step (1), the temperature of fluid A is adjusted to 10-15°C, and the temperature of fluid B is adjusted to 10°C.

[0031] Preferably, in step (2), the molar ratio of the effective components of fluid A and fluid B is 1:1.02 to 1.08, more preferably 1:1.02 to 1.04.

[0032] Preferably, in step (2), the tubular reactor is a tangential tubular reactor.

[0033] More preferably, the tangential flow tubular reactor includes an inlet, a jacket, an electric stirrer, a spiral tube, a stirring column, and an outlet; the inlet and outlet are respectively located on both sides of the tangential flow tubular reactor; the jacket is located on the outer layer of the cavity of the tangential flow tubular reactor; the electric stirrer is located on the outside of the tangential flow tubular reactor and is matched and connected to the threaded tube located inside the cavity of the tangential flow tubular reactor; the stirring column is located on the inner layer of the cavity of the tangential flow tubular reactor; a hollow central stirring shaft is horizontally arranged in the tangential flow tubular reactor, and the spiral tube and fins are arranged on the stirring shaft, with dimethyl silicone oil as the heat exchange medium in the hollow part; the temperature of the tangential flow tubular reactor is precisely controlled by an external heat exchanger. The reactor adopts an internal and external double heat exchange structure, with the hollow spiral tube structure and the outer jacket acting as a dual function, increasing the heat exchange area several times compared to ordinary heat exchangers. The central steel tube can rotate under the drive of a motor and is equipped with a stirring device, which can promote the mixing, diffusion, and mass transfer of reactants.

[0034] More preferably, the volume of the cavity of the tangential flow tubular reactor is 300 ml.

[0035] More preferably, the temperature of the interlayer is 7 to 12°C; wherein, if it is a thiazole-based diazo component, the temperature of the interlayer is 7°C; and if it is a benzothiazole-based diazo component, the temperature of the interlayer is 12°C.

[0036] Preferably, in step (2), the diazo reaction temperature is 10-30°C; wherein, if it is a thiazole-based diazo component, the diazo reaction temperature is 10-15°C; if it is a benzothiazole-based diazo component, the diazo reaction temperature is 20-30°C.

[0037] Preferably, in step (2), the certain residence time is 20 to 90 seconds; wherein, if it is a thiazole diazonium component, the residence time is 20 to 45 seconds; if it is a benzothiazole diazonium component, the residence time is 60 to 90 seconds.

[0038] Preferably, in step (2), the general structural formula of the aniline polyether is:

[0039]

[0040] In the formula, R1 = H, or CH3, or CH3O; R2 = (CH2CH2O) n (CH2CH2CH2O) m , where 2≤n≤40 and n is an integer, and 0≤m≤40 and m is an integer.

[0041] Preferably, in step (2), the coupling temperature is controlled at 10-15°C.

[0042] The basic principle of this invention:

[0043] The tangential flow tubular reactor used in this invention is an upgraded product of the conventional tubular reactor. A hollow central stirring shaft is added horizontally to this reactor, with helical tubes and fins mounted on the shaft, and the heat exchange medium flowing through the hollow section. This adds an inner jacket to the outer jacket of the conventional tubular reactor, improving heat exchange efficiency. Furthermore, the helical tubes and fins on the stirring shaft overcome the limitations of microchannel reactors in handling medium-to-high viscosity reaction liquids, and the fins further enhance heat exchange efficiency. These characteristics of the tangential flow tubular reactor used in this invention are highly compatible with the diazotization reaction liquid of thiazole heterocyclic primary amines, which has high heat release, fast reaction rate, and medium viscosity. Therefore, this invention develops a continuous flow process for the diazotization of thiazole heterocyclic primary amines using a tangential flow tubular reactor. Compared to the batch diazotization process, the diazotization reaction temperature of the continuous flow process of this invention can be increased from below 0°C to 10–15°C or higher.

[0044] Compared with the prior art, the beneficial effects of the present invention are:

[0045] (1) This invention greatly improves the safety of the diazotization process and reduces the risk of misoperation;

[0046] (2) This invention improves the reaction conversion rate of diazotization and shortens the time when the diazo liquid exists alone, thereby simultaneously improving the conversion rate of the coupling reaction and the purity of the coupling reaction solution, and the process is more environmentally friendly.

[0047] (3) Compared with the conventional intermittent method, the total yield of this invention is increased by 10%;

[0048] (4) The diazo temperature of the present invention is carried out at room temperature, which saves energy consumption. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of the reaction process of the continuous flow process for the azo polyether dye of the present invention;

[0050] Figure 2This is a schematic diagram of the overall structure of the tangential flow tubular reactor used in the continuous flow process of the azo polyether dye of this invention.

[0051] The component names corresponding to the various reference numerals in the diagram are:

[0052] 1-Inlet; 2-Jacket; 3-Electric mixer; 4-Spiral tube; 5-Mixing column; 6-Outlet. Detailed Implementation

[0053] To better understand the content of this invention, further description is provided below with reference to specific embodiments and accompanying drawings. It should be understood that these embodiments are only for further illustration of the invention and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the description of this invention, those skilled in the art may make some non-essential modifications or adjustments to the invention, which still fall within the protection scope of this invention.

[0054] The reaction flow of the continuous flow process for azo polyether dyes in Examples 1-5 of this invention is shown below. Figure 1 .

[0055] The overall structure of the tangential flow tubular reactor used in the continuous flow process of azo polyether dyes in Examples 1-5 of this invention is shown below. Figure 2 The tangential flow tubular reactor has a cavity volume of 300 ml. The reactor includes an inlet 1, a jacket 2, an electric stirrer 3, a spiral tube 4, a stirring column 5, and an outlet 6. The inlet 1 and outlet 6 are respectively located on both sides of the reactor. The jacket 2 is located on the outer layer of the reactor cavity. The electric stirrer 3 is located on the outside of the reactor and is connected to the spiral tube 4 located inside the reactor cavity. The stirring column 5 is located on the... The inner layer of the cavity of the tangential flow tubular reactor is described; a hollow central stirring shaft is horizontally arranged in the tangential flow tubular reactor, and the stirring shaft is equipped with the spiral tube 4 and fins. The hollow part is filled with the heat exchange medium dimethyl silicone oil; the temperature of the tangential flow tubular reactor is precisely controlled by an external heat exchanger. The reactor adopts an inner and outer double heat exchange structure. The hollow spiral tube structure and the outer jacket have a dual effect, and the heat exchange area is several times larger than that of ordinary heat exchangers. The central steel tube can be rotated under the drive of a motor. It is equipped with a stirring device, which can promote the mixing, diffusion and mass transfer of reactants.

[0056] The tangential flow tubular reactor used in this invention is an upgraded product of the conventional tubular reactor. A hollow central stirring shaft is added horizontally to this reactor, with helical tubes and fins mounted on the shaft, and the heat exchange medium flowing through the hollow section. This adds an inner jacket to the outer jacket of the conventional tubular reactor, improving heat exchange efficiency. Furthermore, the helical tubes and fins on the stirring shaft overcome the limitations of microchannel reactors in handling medium-to-high viscosity reaction liquids, and the fins further enhance heat exchange efficiency. These characteristics of the tangential flow tubular reactor used in this invention are highly compatible with the diazotization reaction liquid of thiazole heterocyclic primary amines, which has high heat release, fast reaction rate, and medium viscosity. Therefore, this invention develops a continuous flow process for the diazotization of thiazole heterocyclic primary amines using a tangential flow tubular reactor. Compared to the batch diazotization process, the diazotization reaction temperature of the continuous flow process of this invention can be increased from below 0°C to 10–15°C or higher.

[0057] Example 1

[0058] Fluid A: 15-25℃; Dissolve 100g of 2-amino-thiazole (1mol) in 750g of 33% sulfuric acid, adjust the temperature to 10-15℃, and set aside.

[0059] Fluid B: Dissolve 74.6g of 97% sodium nitrite in 180g of water to prepare a solution, keep it at 10℃, and set aside for later use.

[0060] Add 983g (1.01mol) of aniline polyether 20EO and 1000g of water to a 5000mL coupling vessel, stir, and adjust the temperature to 10-15℃ for later use.

[0061] After metering calibration, fluid A was pumped into a tangential flow pipeline reactor (holding capacity 300 mL, jacket temperature controlled at 7℃) at a rate of 40.0 g / min (equivalent to 47.05 mmol / min for 2-amino-thiazole) and fluid B at a rate of 11.98 g / min (equivalent to 50.9 mmol / min for sodium nitrite) simultaneously. The reaction temperature was 13℃ and the residence time was 25 sec.

[0062] The diazonium solution obtained immediately flows into the coupling tank, and the coupling temperature is controlled at 10-15℃. After the diazonium solution is added, a small amount of water is pumped into the reactor to flush out the diazonium solution in the reactor. Stirring is continued for 30 minutes until the coupling is complete, and the azo polyether dye shown in Formula III is obtained.

[0063] The coupling solution was 3295g, with an HPLC purity of 95.84% and a color value of 11.68 L·g. -1 ·cm -1 The yield was approximately 97.2%.

[0064]

[0065] Example 2

[0066] Fluid A: 15-25℃; Dissolve 114g of 2-amino-5-methylthiazole (1mol) in 800g of 33% sulfuric acid, adjust the temperature to 10-15℃, and set aside.

[0067] Fluid B: Dissolve 74.6g of 97% sodium nitrite in 180g of water to prepare a solution, keep it at 10℃, and set aside for later use.

[0068] In a 5000mL coupling vessel, add 997g (1.01mol) of m-toluidine polyether 20EO and 1000g of water, respectively. Stir and adjust the temperature to 10-15℃ for later use.

[0069] After metering calibration, fluid A was pumped into a tangential flow pipeline reactor (holding capacity 300 mL, jacket temperature controlled at 7℃) at a rate of 40.0 g / min (equivalent to 43.76 mmol / min for 2-amino-5-methylthiazole) and fluid B at a rate of 11.14 g / min (equivalent to 47.26 mmol / min for sodium nitrite). The reaction temperature was 13℃ and the residence time was 25 sec.

[0070] The diazonium solution obtained immediately flows into the coupling tank, and the coupling temperature is controlled at 10-15℃. After the diazonium solution is added, a small amount of water is pumped into the reactor to flush out the diazonium solution in the reactor. Stirring is continued for 30 minutes until the coupling is complete, and the azo polyether dye shown in Formula IV is obtained.

[0071] The coupling solution was 3362g, with an HPLC purity of 98.24% and a color value of 12.07 L·g. -1 ·cm -1 The yield was approximately 97.3%.

[0072]

[0073] Example 3

[0074] Fluid A: 15-25℃; Dissolve 164g of 2-amino-4-methylbenzothiazole (1mol) in 800g of 65% sulfuric acid, adjust the temperature to 10-15℃, and set aside.

[0075] Fluid B: Cool 320g of 41% nitrosyl sulfuric acid to 10℃ and set aside.

[0076] Add 983g (1.01mol) of aniline polyether 20EO and 1000g of water to a 5000mL coupling vessel, stir, and adjust the temperature to 10-15℃ for later use.

[0077] After metering calibration, fluid A was pumped into a tangential flow pipeline reactor (holding capacity 300 mL, jacket temperature controlled at 12℃) at a rate of 30.0 g / min (equivalent to 31.06 mmol / min for 2-amino-4-methylbenzothiazole) and fluid B at a rate of 9.94 g / min (equivalent to 31.99 mmol / min for nitrosylsulfuric acid). The reaction temperature was 20℃ and the residence time was 60 sec.

[0078] The diazonium solution obtained immediately flows into the coupling tank, and the coupling temperature is controlled at 10-15℃. After the diazonium solution is added, a small amount of water is pumped into the reactor to flush out the diazonium solution in the reactor. Stirring is continued for 30 minutes until the coupling is complete, and the azo polyether dye shown in Formula V is obtained.

[0079] The coupling solution was 3455g, with an HPLC purity of 96.28% and a color value of 12.56 L·g. -1 ·cm -1 The yield was approximately 96.8%.

[0080]

[0081] Example 4

[0082] Fluid A: 15-25℃; Dissolve 180g of 2-amino-6-methoxybenzothiazole (1mol) in 800g of 65% sulfuric acid, adjust the temperature to 10-15℃, and set aside.

[0083] Fluid B: Cool 320g of 41% nitrosyl sulfuric acid to 10℃ and set aside.

[0084] In a 5000mL coupling vessel, add 997g (1.01mol) of m-toluidine polyether 20EO and 1000g of water, respectively. Stir and adjust the temperature to 10-15℃ for later use.

[0085] After metering calibration, fluid A was simultaneously pumped into a tangential flow tubular reactor (holding capacity 300 mL, jacket temperature controlled at 12℃) at a rate of 30.0 g / min (equivalent to 30.61 mmol / min for 2-amino-6-methoxybenzothiazole) and fluid B at a rate of 9.79 g / min (equivalent to 31.53 mmol / min for nitrosylsulfuric acid). The reaction temperature was 20℃ and the residence time was 60 sec.

[0086] The diazonium solution obtained immediately flows into the coupling tank, and the coupling temperature is controlled at 10-15℃. After the diazonium solution is added, a small amount of water is pumped into the reactor to flush out the diazonium solution in the reactor. Stirring is continued for 30 minutes until the coupling is complete, and the azo polyether dye shown in Formula VI is obtained.

[0087] The coupling solution was 3465g, with an HPLC purity of 98.84% and a color value of 13.08 L·g. -1·cm -1 The yield was approximately 96.3%.

[0088]

[0089] Example 5

[0090] Fluid A: 15-25℃; Dissolve 164g of 2-amino-4-methylbenzothiazole (1mol) in 800g of 65% sulfuric acid, adjust the temperature to 10-15℃, and set aside.

[0091] Fluid B: Cool 320g of 41% nitrosyl sulfuric acid to 10℃ and set aside.

[0092] In a 5000mL coupling vessel, add 539g (1.01mol) of aniline polyether 10EO and 1000g of water, respectively. Stir and adjust the temperature to 10-15℃. Set aside for later use.

[0093] After metering calibration, fluid A was pumped into a tangential flow pipeline reactor (holding capacity 300 mL, jacket temperature controlled at 12℃) at a rate of 30.0 g / min (equivalent to 31.06 mmol / min for 2-amino-4-methylbenzothiazole) and fluid B at a rate of 9.94 g / min (equivalent to 31.99 mmol / min for nitrosylsulfuric acid). The reaction temperature was 20℃ and the residence time was 60 sec.

[0094] The diazonium solution obtained immediately flows into the coupling tank, and the coupling temperature is controlled at 10-15℃. After the diazonium solution is added, a small amount of water is pumped into the reactor to flush out the diazonium solution in the reactor. Stirring is continued for 30 minutes until the coupling is complete, and the azo polyether dye shown in Formula VII is obtained.

[0095] Coupling solution 2720g, HPLC purity 97.65%, color value 16.12 L·g -1 ·cm -1 The yield was approximately 97.0%.

[0096]

[0097] Comparative Example 1

[0098] Add 800g of 33wt% sulfuric acid to a 2500ml flask, then add 100g (1.0mol) of 2-amino-thiazole, and cool with chilled brine to below 5℃. Dissolve 74.6g of 97% sodium nitrite in 180g of water to prepare a solution, keep at 10℃, and add the sodium nitrite solution dropwise at 10℃. React for 3 hours to obtain the diazonium salt. Add 983g of aniline polyether 20EO to a 5000ml flask, add 1000g of ice water, and then add 5g of urea. Stir in an ice bath. Slowly add the prepared diazonium solution dropwise, controlling the temperature at 0-5℃ during the addition process. After the addition is complete, continue the reaction naturally for 6-10 hours until coupling is complete. The coupling solution is 3125g, with an HPLC purity of 78.69% and a color value of 9.02 L·g. -1 ·cm -1 The yield was approximately 74.30%.

[0099] Comparative Example 2

[0100] Add 800g of 65wt% sulfuric acid to a 2500ml flask, then add 164g (1.0mol) of 2-amino-thiazole, and cool with chilled brine to below 0℃. Slowly add 320g (1.03mol) of 41wt% nitrosylsulfonic acid, and react at 0-5℃ for 5 hours to obtain the diazonium salt. Add 983g of aniline polyether 20EO to a 5000ml flask, add 1000g of ice water, and then add 5g of urea, and stir in an ice bath. Slowly add the prepared diazonium solution, controlling the temperature at 0-5℃ during the addition process. After the addition is complete, continue the reaction naturally for 6-10 hours until coupling is complete. The coupling solution is 3245g, with an HPLC purity of 82.28% and a color value of 10.62 L·g. -1 ·cm -1 The yield was approximately 84.5%.

[0101] This invention discloses a continuous flow process for azo polyether dyes. The main steps include: dissolving a thiazole or benzothiazole diazo component in an aqueous sulfuric acid solution to form a diazo component solution; preparing a diazotizing agent solution; and pumping both solutions into a tubular reactor at a constant rate using a plunger pump. After a certain residence time, complete diazotization is achieved. The resulting diazonium salt solution continuously flows into an aniline polyether solution for immediate coupling until complete coupling. This invention achieves rapid and complete diazotization at room temperature and immediate coupling through continuous flow diazotization, while simultaneously reducing the amount of acid used for coupling. Compared with conventional batch processes, the overall reaction yield is increased by 10%. This invention's process adheres to green chemistry principles while also achieving a balance between safety and economy, possessing significant industrial application value.

[0102] The foregoing description is not intended to limit the invention, nor is the invention limited to the examples given. Any changes, modifications, additions, or substitutions made by those skilled in the art within the scope of the invention should also be considered within the protection scope of the invention.

Claims

1. A continuous flow process for azo polyether dyes, characterized in that, Includes the following steps: (1) Dissolve the diazo component of formula I (thiazole) or formula II (benzothiazole) in an aqueous sulfuric acid solution to prepare fluid A, and dissolve the diazotizing agent in sulfuric acid or water to prepare fluid B; In formula I, X = H or CH3; In Formula II, X = H or CH3; Y = H or CH3, or NO2 or CH3O; Z = H or CH3; (2) Fluid A and fluid B are pumped into the tubular reactor at constant rates by plunger pumps to maintain a suitable diazo reaction temperature. After a certain residence time, they are completely diazotized. The generated diazo salt solution is continuously flowed into the aniline polyether solution for immediate coupling until complete coupling, thus obtaining a polyether dye solution.

2. The continuous flow process for an azo polyether dye as described in claim 1, characterized in that, In step (1), the concentration of the sulfuric acid aqueous solution is 30% to 85%; wherein, if sodium nitrite is used as the diazotizing agent, the concentration of the sulfuric acid aqueous solution is 30% to 35%; if nitrosylsulfuric acid is used as the diazotizing agent, the concentration of the sulfuric acid aqueous solution is 65% to 85%.

3. The continuous flow process for an azo polyether dye as described in claim 1, characterized in that, In step (1), the diazotizing agent is sodium nitrite or nitrosylsulfuric acid; wherein, if it is a thiazole-based diazo component, the diazotizing agent is a 25% to 32% sodium nitrite aqueous solution; if it is a benzothiazole-based diazo component, the diazotizing agent is a 35% to 42% nitrosylsulfuric acid.

4. The continuous flow process for an azo polyether dye as described in claim 1, characterized in that, In step (2), the molar ratio of the effective components of fluid A and fluid B is 1:1.02 to 1.

08.

5. The continuous flow process for an azo polyether dye as described in claim 1, characterized in that, In step (2), the tubular reactor is a tangential tubular reactor.

6. The continuous flow process for an azo polyether dye as described in claim 5, characterized in that, The tangential flow tubular reactor includes an inlet (1), a jacket (2), an electric stirrer (3), a spiral tube (4), a stirring column (5), and an outlet (6); the inlet (1) and the outlet (6) are respectively located on both sides of the tangential flow tubular reactor; the jacket (2) is located on the outer layer of the cavity of the tangential flow tubular reactor; the electric stirrer (3) is located on the outside of the tangential flow tubular reactor and is matched and connected to the spiral tube (4) located inside the cavity of the tangential flow tubular reactor; the stirring column (5) is located on the inner layer of the cavity of the tangential flow tubular reactor.

7. The continuous flow process for an azo polyether dye as described in claim 6, characterized in that, The temperature of the interlayer (2) is 7 to 12°C; wherein, if it is a thiazole diazonium component, the temperature of the interlayer (2) is 7°C; if it is a benzothiazole diazonium component, the temperature of the interlayer (2) is 12°C.

8. The continuous flow process for an azo polyether dye as described in claim 1, characterized in that, In step (2), the diazo reaction temperature is 10-30℃; wherein, if it is a thiazole-based diazo component, the diazo reaction temperature is 10-15℃; if it is a benzothiazole-based diazo component, the diazo reaction temperature is 20-30℃.

9. The continuous flow process for an azo polyether dye as described in claim 1, characterized in that, In step (2), the specified residence time is 20 to 90 seconds; wherein, if it is a thiazole diazonium component, the residence time is 20 to 45 seconds; and if it is a benzothiazole diazonium component, the residence time is 60 to 90 seconds.

10. A continuous flow process for an azo polyether dye as described in claim 1, characterized in that, In step (2), the coupling temperature is controlled at 10-15℃.

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