Preparation process of composite reactive dye

Abstract

The invention discloses a preparation process of a composite reactive dye, which comprises the following steps: mixing cyanuric chloride and meta-ester, pulping, carrying out primary condensation, adding 2, 4-diaminobenzene sodium sulfonate, carrying out secondary condensation, and carrying out diazotization to obtain a secondary condensed diazonium solution; the preparation method comprises the following steps: diazotizing p-aminobenzene sulfonic acid at low temperature, carrying out acidic coupling reaction on the diazotized p-aminobenzene sulfonic acid and H acid to obtain an acid coupling solution, adding N-ethyl-3-carbamoyl-4-methyl-6-hydroxy-2-pyridone dry powder, adjusting alkali, and dissolving; and adding a secondary diazonium solution into the dissolved clear solution, and carrying out alkaline coupling reaction to obtain an alkaline coupling solution, namely the composite reactive dye raw stock. According to the preparation process of the composite reactive dye, a compounding and color mixing procedure is omitted, the composite dye is synchronously prepared in a synthesis stage, and the primary pulp has the advantages of good solubility, high solid content, smooth material transmission, low spray drying energy consumption and the like; the product has good fastness, the proportion of yellow and blue can be adjusted in the synthesis stage, the color of the dye can be converted between light green and dark green, and the requirements of the downstream industry for various color matching of the product are met.

Description

Technical Field

[0001] The invention belongs to the field of reactive dye synthesis, and in particular relates to a preparation process of a composite reactive dye. Background Art

[0002] Reactive dyes are highly reactive and economical, and they account for a large proportion in the dye industry. However, there are fewer varieties of green reactive dyes, and even fewer varieties of green dyes with a single structure. Most green dyes are made of a combination of blue and yellow.

[0003] CI Reactive Blue 194, a navy blue dye with green light, is often mixed with yellow dye to form a green dye to make up for the lack of green reactive dye varieties. However, there are many problems in the actual compounding process. First, the current process for synthesizing CI Reactive Blue 194 alone is not perfect. For example, the "Synthesis Process of Reactive Dyes Containing Heterobiactive Groups" published in the first issue of Dyes and Coloring Volume 41 introduced the synthesis technology of CI Reactive Blue 194 in the early years. The process control was rough, and salting out and purification were still required to stabilize the application performance of the dye, resulting in relatively large losses. The experimental preparation method of CI Reactive Blue 194 introduced in "Synthesis Research on Reactive Blue M-2GE" published in the third issue of Dyes and Coloring Volume 50 solved the problem of low dye fixation rate and unstable fastness, but there were multiple dissolution and feeding steps in the reaction, the solid content of the obtained raw pulp was too low, the energy consumption of spray drying was high, and the cost would increase in subsequent large-scale production. In addition, the Integ value of the obtained dye at low concentration (owf) was not good enough, less than 10 at 0.5%, which was difficult to meet the needs of light-color printing and dyeing.

[0004] A Chinese patent with publication number CN 111100478 A discloses a method for preparing a three-active-base blue dye: adding cyanuric chloride and a dispersant to an ice-water mixture to obtain a pulping liquid; adding a solid para-ester to the pulping liquid, adding a mixed alkali solution to adjust the alkali after continuing to pulp, and performing a condensation reaction to obtain a first condensation product; adding a solid meta-diol to the first condensation product to perform a condensation reaction to obtain a second condensation product; cooling the second condensation product, adding an auxiliary agent, and sequentially adding hydrochloric acid and sodium nitrite to perform diazotization to obtain a diazo liquid; coupling the second diazo liquid with an H acid solution to obtain an acid coupling solution; adding hydrochloric acid and sodium nitrite to 6-β-ethylsulfonyl sulfate-2-naphthylamine-1-sulfonic acid to perform a diazotization reaction to obtain 6-β-ethylsulfonyl sulfate-2-naphthylamine-1-sulfonic acid diazonium salt, adding the diazonium salt to the acid coupling solution, and performing an alkaline coupling reaction to obtain an active blue dye. The blue reactive dye provided by the above patent is significantly different from CI reactive blue 194 in structure and has three active groups, which significantly improves the dye uptake and color fastness of the dye. However, when used for compounding with green dyes, in order to ensure compatibility, the reactivity requirements for the combined yellow dye are also relatively high, the selectivity is low and the economy is poor, and the printing and dyeing process control is cumbersome; and the diazonium solution is first acidically coupled with the H acid solution, and the obtained acid coupling solution is then alkaline coupled with 6-β-ethylsulfonyl sulfate-2-naphthylamine-1-sulfonic acid diazonium salt. The acid-base coupling order of the two diazo components is different, so that the two azo components are connected to the H acid at different bond positions, further increasing the structural difference; in addition, the linear synthesis route prolongs the synthesis time and lengthens the production cycle. The dissolved H acid in the process to participate in the reaction also reduces the solid content of the dye slurry to a certain extent, and the spray drying cost is relatively high.

[0005] There are also related reports on yellow dyes that can be used for compounding. For example, the Chinese patent with publication number CN1709981A discloses a reactive light yellow SGE dye and its synthesis method. Its synthesis route is a condensation reaction of sodium 2,4-diaminobenzenesulfonate and cyanuric chloride, and the condensate is coupled with N-ethyl-3-formylamino-4-methyl-6-hydroxy-2-pyridone after diazotization, and then reacted with p-(β-sulfate ethyl sulfone) aniline dicondensation. The structural dye has good solubility, but the synthesis method provided is rough, and the control of each unit reaction is simple and wide, which makes the quality of the dye stock unstable, resulting in large batch differences in large-scale production, and it is more difficult to use for dye compounding. Sometimes salting out treatment is required, and the yield is low.

[0006] Secondly, whether it is wet or dry mixing, it is still necessary to complete the separate synthesis of yellow and blue colors first, and then complete the compounding according to demand after standardization. The cycle is long and the equipment occupancy rate is high. In the subsequent compounding process, when the proportion of yellow and blue is adjusted from light green to dark green according to the different brightness, it is easy to cause low compatibility and poor levelness in the dye application process due to different dye structures and SERF values. Summary of the invention

[0007] The present invention aims to provide a preparation process of a composite reactive dye, and the key technology is that the preparation process can simultaneously synthesize a composite dye including a blue component and a yellow component, eliminating the compounding and coloring process. The prepared composite reactive dye can be used for dyeing and printing of cotton, linen and viscose fibers, and has the advantages of rich color, excellent solubility, high soaping and heat pressing fastness, and no color change after finishing at high temperature. In particular, it can still maintain a good dyeing depth value under low owf, and has good printing and dyeing reproducibility.

[0008] In order to achieve the above-mentioned purpose of the invention, the technical solution provided by the present invention is:

[0009] A preparation process of a composite reactive dye, the preparation process comprising the following steps:

[0010] 1) adding ice and water to cyanuric chloride, adding a meta-ester, adding a dispersant, mixing and stirring, and beating to obtain a beating material;

[0011] 2) adding baking soda to sodium acetate, adding water, stirring and dissolving to obtain a mixed alkali solution;

[0012] 3) adding the mixed alkali solution obtained in step 2) dropwise to the pulp obtained in step 1) for condensation reaction, controlling the temperature at 5-10° C. and maintaining the pH value at 1.5-2.5, and obtaining a condensate after the reaction is completed;

[0013] 4) adding sodium 2,4-diaminobenzenesulfonate to the first condensate obtained in step 3), first controlling the temperature at 20-25° C., maintaining the pH value at 3.5-4.0, and reacting for 1-2 hours, then controlling the temperature at 30-35° C., maintaining the pH value at 4.0-4.5, and reacting for 1-2 hours, and the reaction is complete to obtain a second condensate;

[0014] 5) cooling the dicondensed solution obtained in step 4), adding a dispersant and hydrochloric acid, and dripping a sodium nitrite solution, and performing a diazotization reaction to obtain a dicondensed diazo solution;

[0015] 6) After low-temperature diazotization of p-aminobenzenesulfonic acid, add H acid dry powder, keep warm at 15-20°C, maintain pH value at 2.0-2.5, and complete the acid coupling reaction to obtain an acid coupling liquid;

[0016] 7) Adding N-ethyl-3-carbamoyl-4-methyl-6-hydroxy-2-pyridone dry powder to the acid coupling liquid obtained in step 6), adjusting the pH value to 5.5-6.0 until the material is dissolved, then adding the diazonium solution obtained in step 5), maintaining the pH value at 6.0-6.5 with alkali solution, and continuing to maintain the pH to the end point after the addition, the alkaline coupling reaction obtains the alkaline coupling liquid, which is the composite reactive dye stock;

[0017] The composite reactive dye comprises a blue component dye represented by formula (I) and a yellow component dye represented by formula (II), and the molar ratio of the blue component dye to the yellow component dye is 1.0:(0.25-4.0):

[0018]

[0019] In step 1) of the present invention, solid cyanuric chloride and meta-ester are directly added, and the molar ratio of cyanuric chloride to meta-ester is 1:(0.97-1.02).

[0020] Preferably, in step 1), a dispersant NNO is added to improve the dispersing and beating effect.

[0021] Further preferably, the dispersant NNO is added in a ratio of 0.5 to 5‰ of the material volume ratio.

[0022] Preferably, in step 1), the beating time is 1 to 2 hours, and during the beating process, the temperature is maintained below 5°C.

[0023] In step 2) of the present invention, a mixed alkali solution with a buffering effect is prepared to adjust the pH of the primary condensation reaction. Further preferably, the mass ratio of sodium acetate, baking soda and cyanuric chloride is 0.3-0.4:0.6-0.8:1, and the temperature is lowered to 3-6°C after dissolution.

[0024] In the step 3), the mixed alkali solution is added dropwise for 1 to 2 hours. After the addition, the pH value will slowly decrease, and baking soda is continued to maintain the pH value for 1 to 2 hours.

[0025] In the step 4), sodium 2,4-diaminobenzenesulfonate solid is directly added, and the molar ratio of sodium 2,4-diaminobenzenesulfonate to cyanuric chloride is (0.95-1.01):1. The secondary condensation reaction is heated in stages, and the heating rate should not be too fast. Baking soda is used to adjust the pH value during the reaction.

[0026] In the step 5), the diazo reaction of the dicondensate is carried out at low temperature, and a dispersant MF is added to improve fluidity.

[0027] Preferably, ice is added to cool the reaction mixture to 5-10° C. before the reaction, and the amount of dispersant MF used is 0.05-1% by volume of the dicondensate.

[0028] Preferably, in step 5), the molar ratio of hydrochloric acid, sodium nitrite and sodium 2,4-diaminobenzenesulfonate is (2.2-2.6):(0.98-1.06):1.

[0029] Preferably, in step 5), the diazotization reaction temperature is controlled at 5-10° C., and the reaction time is controlled at 2-3 h.

[0030] In step 6) of the present invention, p-aminobenzenesulfonic acid is reacted at low temperature (generally below 10° C.) using conventional diazo methods to obtain a diazonium salt.

[0031] Preferably, in step 6), the molar ratio of p-aminobenzenesulfonic acid to H acid is 1:(0.95-0.99), baking soda is used to adjust the pH value, and the reaction time is 6-8 hours.

[0032] In step 7 of the present invention, the acid-coupled material is viscous and has poor fluidity, and the N-ethyl-3-carbamoyl-4-methyl-6-hydroxy-2-pyridone solid has poor water solubility, and it is difficult to directly add it to the diazo liquid to participate in the reaction. First, the N-ethyl-3-carbamoyl-4-methyl-6-hydroxy-2-pyridone dry powder is added to the acid-coupled liquid, and the solution is adjusted with baking soda, and then the subsequent reaction is participated in, which can shorten the reaction time and improve the conversion rate.

[0033] Preferably, in step 7), the reaction temperature is 8-12° C. and the reaction time is 4-5 h.

[0034] Preferably, in step 7), baking soda is used to adjust the pH value to 5.5-6.0 until the material is dissolved; after the diazo solution is added, 20% pure alkali solution is used to maintain the pH value at 6.0-6.5.

[0035] Preferably, in step 1), step 6) and step 7), the molar ratio of cyanuric chloride, N-ethyl-3-carbamoyl-4-methyl-6-hydroxy-2-pyridone and p-aminobenzenesulfonic acid is 1:(0.2-0.8):(0.2-0.8), and the total molar amount of N-ethyl-3-carbamoyl-4-methyl-6-hydroxy-2-pyridone and p-aminobenzenesulfonic acid is similar to that of cyanuric chloride, and the difference does not exceed ±5%.

[0036] Compared with the existing related technologies, the present invention has the following beneficial effects:

[0037] (1) Composite dyes can be synthesized simultaneously, eliminating the complex color mixing process, reducing equipment occupancy, saving time and labor costs;

[0038] (2) The prepared slurry has good solubility, high solid content, which can reach more than 25%, good fluidity, smooth material transmission, no clogging, and low energy consumption for spray drying;

[0039] (3) Under the premise that the total molar number remains unchanged, the ratio of yellow and blue can be adjusted by adjusting the ratio of N-ethyl-3-carbamoyl-4-methyl-6-hydroxy-2-pyridone and p-aminobenzenesulfonic acid, so that the color of the dye can be changed between light green and dark green, meeting the downstream industry's demand for various color matching of the product;

[0040] (4) Both components of the final synthesized dye have heterobiactive groups of β-vinylsulfone and iso-triazine, with high structural similarity and good compatibility. The dyeing Integ value is high at low concentration (owf), and the color of the fabric is not prone to color difference, with good fastness and reproducibility. DETAILED DESCRIPTION

[0041] Embodiment 1:

[0042] Add 400 kg of bottom water and 1000 kg of crushed ice into a 10-cubic-meter reaction pot①, add 200 kg of cyanuric chloride, 2.5 kg of dispersant NNO, and 310 kg of meta-ester, stir and beat for 1 to 2 hours, keep the temperature below 5°C, and obtain a beating liquid.

[0043] Add 800 kg of bottom water to a 5-cubic-meter dissolving pot, add 80 kg of sodium acetate and 120 kg of baking soda, stir to dissolve, obtain a mixed alkali solution, and cool to 5°C for use.

[0044] Add the mixed alkali solution in the 5-cubic-meter dissolving pot to the pulping liquid in the 10-cubic-meter reaction pot① to start a condensation reaction. Pay attention to the reaction pH and reaction temperature during the dropping process, and ensure that the temperature is 5-10℃ and the pH value is 1.5-2.5. As the reaction proceeds, the pH drops slowly and the dropping speed also starts to slow down. It takes 1-2 hours for the mixed alkali solution to drip. After dripping, the pH will slowly drop. Continue to use baking soda to maintain the pH value for 1-2 hours until the pH stabilizes. Take samples for HPLC detection. The purity of the condensate is greater than 97%, and the condensation reaches the end point of the reaction.

[0045] Add 210kg of solid sodium 2,4-diaminobenzenesulfonate into the first condensation liquid of the 10-cubic-meter reaction pot ①, first turn on the steam and slowly raise the temperature to 25°C, keep warm and adjust with baking soda to maintain the pH value at 3.5-4.0 for 1-2h, then continue to raise the temperature to 30-35°C, keep warm and maintain the pH value at 4.0-4.5 for 1-2h, take a sample for HPLC detection when the reaction time is up, the purity of the second condensation product is greater than 93.5%, and the secondary condensation reaches the reaction end point.

[0046] Add ice to the dicondensate in the 10-cubic-meter reaction pot ①, cool to 6°C, add 20kg dispersant MF, 280kg 30% industrial hydrochloric acid, and drop 240kg 30% sodium nitrite solution. Add the solution over 30 minutes, keep warm at 5-10°C, and react for 2 hours. After the reaction is complete, obtain the dicondensate diazo solution for use.

[0047] Add 300kg bottom water, 500kg ice and 140kg p-aminobenzenesulfonic acid to a 10-cubic-meter reaction pot ②, stir, add 100kg 30% industrial hydrochloric acid, add 175kg 30% sodium nitrite solution, drip it for 30 minutes, keep warm at 5℃, react for 1h, after the reaction is complete, use aminosulfonic acid to eliminate free sodium nitrite, slowly add 300kg H acid powder, after adding, use baking soda to adjust and maintain the pH value at 2.0-2.5, keep warm at 15-20℃, react for 6h, until the acid-coupled reaction ends. Then add 65kg N-ethyl-3-carbamoyl-4-methyl-6-hydroxy-2-pyridone, use baking soda to adjust the pH value to 5.5-6.0 until the material is dissolved.

[0048] Slowly add the diazonium chloride solution and keep the temperature at 8-12°C. Use 20% pure alkali solution to maintain the pH value at 6.0-6.5 during the addition process. Continue to maintain the pH after the addition. React for 4-5 hours to the end point to obtain an alkali solution, which is the composite reactive dye stock.

[0049] The raw pulp is commercialized and then spray-dried to obtain a composite active dye dry powder.

[0050] Embodiment 2:

[0051] The difference from Example 1 is that the dosage of dispersant NNO is 2 kg, and the dosage of dispersant MF is 18 kg.

[0052] Embodiment 3:

[0053] The difference from Example 1 is that the dosage of p-aminobenzenesulfonic acid is 60 kg, 45 kg of 30% industrial hydrochloric acid is added for diazotization of p-aminobenzenesulfonic acid, 75 kg of 30% sodium nitrite solution is added dropwise, the dosage of H acid is 130 kg, and the dosage of N-ethyl-3-carbamoyl-4-methyl-6-hydroxy-2-pyridone is 150 kg.

[0054] Embodiment 4:

[0055] The difference from Example 3 is that the dosage of dispersant NNO is 2 kg, and the dosage of dispersant MF is 18 kg.

[0056] Comparative Example 1:

[0057] The difference from Example 1 is that no dispersant NNO is added before the primary condensation and beating, and no dispersant MF is added to the secondary condensation liquid.

[0058] Comparative Example 2:

[0059] Synthesis of blue dye component: The blue component stock was synthesized on a large scale according to the method introduced in "Synthesis Research of Reactive Blue M-2GE" in Dyes and Coloring Volume 50.

[0060] Synthesis of yellow dye component: Add 200kg bottom water and 500kg crushed ice to the bottom water in a 5-cubic-meter reaction pot, add 100kg cyanuric chloride, stir and beat for 1h, keep the temperature below 5℃, and obtain a beating liquid. Add 500kg bottom water to a 2-cubic-meter dissolving pot, add 150kg para-ester, and adjust the dissolution with baking soda. Add the para-ester solution dropwise to the cyanuric chloride beating liquid, drip it in about 1h, use baking soda to maintain pH 4-5, and react at 0-5℃ for 2h to the end point. After the end point is reached, add sodium 2,4-diaminobenzenesulfonate solution (obtained by dissolving 100kg sodium 2,4-diaminobenzenesulfonate in water), continue to use baking soda to maintain pH 4-5, and react at 25-30℃ for 4h to the end point. After the end of the second reduction, add 140kg of 30% industrial hydrochloric acid, add 120kg of 30% sodium nitrite solution dropwise, and finish dropping for 30 minutes. Keep warm at 0-5°C and react for 2 hours. Then add N-ethyl-3-carbamoyl-4-methyl-6-hydroxy-2-pyridone solution (obtained by adding 110kg of N-ethyl-3-carbamoyl-4-methyl-6-hydroxy-2-pyridone to water and adjusting the pH to 6.0 with baking soda), adjust the pH to 6.5-7.0 with soda ash, keep warm at 10-15°C, and react for 5 hours to obtain yellow dye stock.

[0061] 70% of the blue component and 30% of the yellow component are wet mixed and compounded, and then spray dried to obtain the composite dye dry powder after commercialization.

[0062] Comparative Example 3:

[0063] The difference from Comparative Example 2 is that after the synthesized yellow and blue raw pulps are standardized, they are first spray-dried and transferred to a mixing pot to be dry-blended with 70% blue component and 30% yellow component to obtain a composite dye dry powder after commercialization.

[0064] The composite reactive dye products prepared in Examples 1 to 4 were compared with Comparative Examples 1 to 3. Table 1 shows the data on sample appearance, purity of the yellow and blue components, solubility, solid content and production cycle; Table 2 shows the Integ value data at different dyeing depths; Table 3 shows the test data on the partial fastness of the standardized samples.

[0065] Table 1 Appearance, purity and solubility of the yellow and blue components, solid content and production cycle of the samples prepared in the examples and comparative examples

[0066]

[0067] Table 2 Integ values ​​of samples prepared in Examples and Comparative Examples at different dyeing depths

[0068]

[0069] Table 3 Test data of fastness of samples prepared in Examples and Comparative Examples

[0070]

[0071] It can be seen from the data in Table 1 that the sum of the purity of the blue dye and the yellow dye components in the composite dye prepared by the synchronous synthesis process of the present invention is about 93%, which can be increased by about 5% at most compared with the traditional technology, and the solubility is better, the solid content can reach more than 25%, the energy consumption of spray drying is low, the entire production time of the product can be shortened by about 10-30%, and the time cost is lower; and Table 2 shows that at a lower dyeing depth, the composite dye prepared by the present invention can still maintain the advantage in color depth value, and the light dyeing is also excellent; compared with the data in Table 3, it can be seen that the composite dye synthesized by the technology of the present invention has better soap washing and heat pressing fastness.

Claims

1. A process for preparing a composite reactive dye, characterized in that: The preparation process comprises the following steps: 1) adding ice and water to cyanuric chloride, adding a meta-ester, adding a dispersant, mixing and stirring, and beating to obtain a beating material; 2) adding baking soda to sodium acetate, adding water, stirring and dissolving to obtain a mixed alkali solution; 3) adding the mixed alkali solution obtained in step 2) dropwise to the pulp obtained in step 1) for condensation reaction, controlling the temperature at 5-10° C. and maintaining the pH value at 1.5-2.5, and obtaining a condensate after the reaction is completed; 4) adding sodium 2,4-diaminobenzenesulfonate to the first condensate obtained in step 3), first controlling the temperature at 20-25° C., maintaining the pH value at 3.5-4.0, and reacting for 1-2 hours, then controlling the temperature at 30-35° C., maintaining the pH value at 4.0-4.5, and reacting for 1-2 hours, and the reaction is complete to obtain a second condensate; 5) cooling the dicondensed solution obtained in step 4), adding a dispersant and hydrochloric acid, and dripping a sodium nitrite solution, and performing a diazotization reaction to obtain a dicondensed diazo solution; 6) After low-temperature diazotization of p-aminobenzenesulfonic acid, add H acid powder, keep warm at 15-20°C, maintain pH value at 2.0-2.5, and complete the acid coupling reaction to obtain an acid coupling liquid; 7) Adding N-ethyl-3-carbamoyl-4-methyl-6-hydroxy-2-pyridone dry powder to the acid coupling liquid obtained in step 6), adjusting the pH value to 5.5-6.0 until the material is dissolved, then adding the diazonium solution obtained in step 5), maintaining the pH value at 6.0-6.5 with alkali solution, and continuing to maintain the pH to the end point after the addition, the alkaline coupling reaction obtains the alkaline coupling liquid, which is the composite reactive dye stock; The composite reactive dye comprises a blue component dye represented by formula (I) and a yellow component dye represented by formula (II), and the molar ratio of the blue component dye to the yellow component dye is 1.0:(0.25-4.0):

2. The preparation process of the composite reactive dye according to claim 1, characterized in that: In the step 1), the molar ratio of cyanuric chloride to meta-ester is 1:(0.97-1.02); the dispersant is NNO, the amount of NNO is 0.5-5‰ material volume ratio, and the beating time is 1-2h.

3. The preparation process of the composite reactive dye according to claim 1, characterized in that: In the step 2), the mass ratio of sodium acetate, baking soda and cyanuric chloride is 0.3-0.4:0.6-0.8:1, and the temperature is lowered to 3-6° C. after dissolution.

4. The preparation process of the composite reactive dye according to claim 1, characterized in that: In the step 3), the mixed alkali solution is added dropwise for 1 to 2 hours, and after the addition, baking soda is continued to maintain the pH value for 1 to 2 hours.

5. The preparation process of the composite reactive dye according to claim 1, characterized in that: In the secondary condensation reaction in step 4), the molar ratio of sodium 2,4-diaminobenzenesulfonate to cyanuric chloride is (0.95-1.01):1, and baking soda is used to adjust the pH value.

6. The preparation process of the composite reactive dye according to claim 1, characterized in that: In the step 5), ice is added to cool the mixture to 5-10° C. before the diazo reaction. The dispersant is MF, and the amount of MF is 0.05-1% by volume of the dicondensate. The molar ratio of hydrochloric acid, sodium nitrite and sodium 2,4-diaminobenzenesulfonate is (2.2-2.6):(0.98-1.06):

1.

7. The preparation process of the composite reactive dye according to claim 1, characterized in that: The temperature of the diazotization reaction in step 5) is controlled at 5-10° C., and the reaction time is controlled at 2-3 h.

8. The preparation process of the composite reactive dye according to claim 1, characterized in that: In the step 6), the molar ratio of p-aminobenzenesulfonic acid to H acid is 1:(0.95-0.99), baking soda is used to adjust the pH value, and the reaction time is 6-8 hours.

9. The preparation process of the composite reactive dye according to claim 1, characterized in that: In the step 7), the reaction temperature is 8-12° C. and the reaction time is 4-5 h.

10. The preparation process of the composite reactive dye according to claim 1, characterized in that: In the steps 1), 6) and 7), the molar ratio of cyanuric chloride, N-ethyl-3-carbamoyl-4-methyl-6-hydroxy-2-pyridone and p-aminobenzenesulfonic acid is 1:(0.2-0.8):(0.2-0.8), and the total molar amount of N-ethyl-3-carbamoyl-4-methyl-6-hydroxy-2-pyridone and p-aminobenzenesulfonic acid is similar to that of cyanuric chloride, and the difference does not exceed ±5%.

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