A multi-purpose, high-performance, functional, environmentally friendly reactive red dye and its preparation method

Abstract

The invention provides a multi-purpose, high-performance, functional, and environmentally friendly reactive red dye and a preparation method thereof, which solve the common usage defects of existing reactive red dyes, such as low solubility, poor salt and alkali resistance, poor levelness and reproducibility, and low fixation rate improvement, making them difficult to apply to low-salt, small bath ratio dyeing and low-urea printing, and easily causing color flocculence, staining, and poor washing fastness and wet treatment fastness after dyeing. The multi-purpose, high-performance, functional, and environmentally friendly reactive red dye and a preparation method thereof have high solubility, good fixation rate, salt and alkali resistance stability, and color fastness, high stability after dyeing, and bright color. The multi-purpose, high-performance, functional, and environmentally friendly reactive red dye can be widely used in dip dyeing, pad dyeing, and inkjet printing of cotton, linen, cellulose fiber, protein fiber, or rayon fiber fabrics, and the multi-purpose, low-production cost, and large-scale promotion and application are also possible.

Description

Technical Field

[0001] The present invention belongs to the field of fine chemicals, and specifically relates to a multi-purpose, high-performance, functional, environmentally friendly reactive red dye and a preparation method thereof, and their application in dyeing and printing of fiber fabrics; in particular, their application in dip dyeing, pad dyeing or inkjet printing of cotton, linen, cellulose fibers, polyamide fibers, protein fibers or rayon fibers. Background Art

[0002] Reactive dyes are new water-soluble dyes that appeared in the 1950s. They have remarkable characteristics such as bright colors, excellent application performance, easy use, and strong applicability. The dye molecules contain active groups that react with hydroxyl groups in cellulose and amino groups in protein fibers. During dyeing, they form "dye-fiber" compounds with fibers and are widely used in the dyeing and printing of cellulose fibers, silk, and viscose fibers.

[0003] Red reactive dyes, one of the three primary colors, are important reactive dyes. Commercial red dyes currently on the market, such as CI Reactive Red 195, can produce a vibrant red color when dyeing cellulose fibers. However, these dyes suffer from low solubility, poor salt and alkali resistance, poor levelness and reproducibility, low build-up, and a fixation rate of only around 85%. This makes them difficult to apply to low-salt, low-bath-ratio dyeing and low-urea printing for various fabrics such as cotton, linen, and polyamide blends. They are particularly difficult to apply to cold pad-batch dyeing and the preparation of digital inkjet prints.

[0004] Entering the 21st century, due to environmental and ecological constraints and economic factors, the requirements for the production and preparation of reactive dyes, color uptake, fixation rate, color fastness, especially the performance suitable for low-salt and small bath ratio dyeing of textiles, low urea printing, cold pad-batch dyeing, and preparation of digital inkjet printing, as well as dyeing wastewater are becoming increasingly higher.

[0005] Red reactive dyes are an important color tone of reactive dyes. How to improve their solubility, salt and alkali resistance, levelness and reproducibility, and lifting performance, so that they can be used for low-salt and small bath ratio dyeing and low-urea printing of various fabrics such as cotton, linen, and polyamide blended fibers, and especially highlight their application functions in cold pad-batch dyeing and digital inkjet printing; and how to apply them to a wider range of functional textile materials, is a problem that needs to be solved. Summary of the Invention

[0006] The purpose of the present invention is to provide a multi-purpose, high-performance, functional, and environmentally friendly reactive red dye based on the existing technology. The dye has high solubility, good color fixation rate, salt and alkali stability, color fastness, high stability after dyeing, and bright color. The dye can be widely used in dip dyeing, pad dyeing, and inkjet printing of cotton, linen, cellulose fiber, polyamide fiber, protein fiber, or rayon fiber fabrics. The production cost is low and the dye can be widely promoted and applied.

[0007] Another object of the present invention is to provide a method for preparing the reactive red dye.

[0008] A third object of the present invention is to provide the application of the above-mentioned reactive red dye in fiber textile printing and dyeing, particularly in the exhaust dyeing, pad dyeing or ink-jet printing of cotton, flax, cellulose fiber, polyamide fiber, protein fiber or rayon fiber.

[0009] The technical solutions of the present invention are as follows:

[0010] The reactive red dye shown in formula I,

[0011]

[0012] in,

[0013] R1 represents H, SO3M, C1-C4 alkyl or C1-C4 alkoxy;

[0014] R2 represents H, SO3M, C1-C4 alkyl or C1-C4 alkoxy;

[0015] Ring A represents a phenyl group or a naphthyl group;

[0016] R3 represents H, SO3M, C1-C4 alkyl or C1-C4 alkoxy;

[0017] R4 represents SO2CH2CH2OSO3M or SO2CH2CH2;

[0018] M represents H, Na or K.

[0019] For the present invention, in a preferred embodiment, R1 represents H, SO3Na, methyl, ethylmethoxy or ethoxy.

[0020] In a more preferred embodiment, R1 represents H or SO3Na.

[0021] For the present invention, in a preferred embodiment, R2 represents H, SO3Na, methyl, ethylmethoxy or ethoxy.

[0022] In a more preferred embodiment, R2 represents H or SO3Na.

[0023] For the present invention, in a preferred embodiment, R3 represents H, SO3Na, methyl, ethylmethoxy or ethoxy.

[0024] In a more preferred embodiment, R3 represents H, SO3Na or methoxy.

[0025] In a preferred embodiment, M represents Na or K.

[0026] In a more preferred embodiment, M represents Na.

[0027] For the present invention, the reactive red dye shown in Formula I can be selected from the following compounds, but is not limited to one of the following compounds:

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036] The present invention also provides a method for preparing the reactive red dye shown in Formula I, and the synthetic route is as follows:

[0037] a) When R4 represents SO2CH2CH2OSO3M, its synthetic route is as follows:

[0038]

[0039]

[0040] B) when R2 represents SO2CH2CH2, its synthetic route is as follows:

[0041]

[0042] Wherein, M represents Na or K.

[0043] In a preferred embodiment, the method for preparing the reactive red dye shown in the above formula I comprises the following steps:

[0044] a) When R4 represents SO2CH2CH2OSO3M, its synthetic route is as follows:

[0045] (1) Compound 1 is dissolved in an alkaline solution, the pH of which is adjusted to 5.5-6.8, and then added to an aqueous solution of compound 4. A primary condensation reaction is carried out at a temperature of 0-5°C to prepare compound II-1, thereby obtaining a primary condensation solution I.

[0046] (2) Compound 3 is dispersed in water, hydrochloric acid is added, and after mixing, the temperature of the resulting mixture is adjusted to 0-5°C, and sodium nitrite is added, and a diazotization reaction is carried out while maintaining the temperature at 0-5°C to obtain diazo solution I;

[0047] (3) The diazo solution I obtained in step (2) and the primary condensation solution I obtained in step (1) are uniformly mixed, the pH value thereof is adjusted to 6.0-6.5, and a coupling reaction is carried out at a temperature of 10-15° C. to prepare compound II-1a, thereby obtaining a coupling reaction solution I;

[0048] (4) Compound 4 is dissolved in an alkaline solution, the pH of which is adjusted to 5.5-6.8, and then added to an aqueous solution of Compound 2. A primary condensation reaction is carried out at a temperature of 0-5°C to prepare Compound II-2, thereby obtaining a primary condensation solution II.

[0049] (5) Dispersing compound 5 in water, adding hydrochloric acid, and after mixing evenly, adjusting the temperature of the resulting mixture to 0-5°C, then adding sodium nitrite, and performing a diazotization reaction while maintaining the temperature at 0-5°C to obtain diazo solution II;

[0050] (6) Evenly mixing the diazo solution II obtained in step (5) and the primary condensation solution II obtained in step (4), adjusting the pH value to 6.0-6.5, and performing a coupling reaction at a temperature of 10-15° C. to prepare compound II-2a, thereby obtaining a coupling reaction solution II;

[0051] (7) uniformly mixing the coupling reaction solution I obtained in step (3) and the coupling reaction solution II obtained in step (6), adding hydroxyethylethylenediamine, adjusting the pH value to 6.5-7.5, and performing a secondary condensation reaction at a temperature of 40-50° C. to obtain a finished dye solution, which was dried to obtain a reactive red dye represented by formula I;

[0052] b) When R2 represents SO2CH2CH2, it comprises the following steps: adding an alkaline solution to the finished dye solution obtained in step 7) to adjust its pH value to 8.5-9.5, carrying out a hydrolysis reaction at a temperature of 20-30°C, and drying the resulting reaction solution to obtain the reactive red dye represented by formula I.

[0053] The present invention can use appropriate acid, base or salt (such as hydrochloric acid, soda ash) to adjust the pH value of the solution as needed.

[0054] In step a):

[0055] In a preferred embodiment, in step 1), the alkaline solution is sodium hydroxide solution, sodium bicarbonate solution, potassium hydroxide solution or potassium bicarbonate solution.

[0056] In a preferred embodiment, in step 1), the molar ratio of compound 1 to compound 2 is 1:1.1-1.5, preferably 1:1.2.

[0057] In a preferred embodiment, in step 4), the alkaline solution is sodium hydroxide solution, sodium bicarbonate solution, potassium hydroxide solution or potassium bicarbonate solution.

[0058] In a preferred embodiment, in step 4), the molar ratio of compound 4 to compound 2 is 1:1.1-1.5, preferably 1:1.2.

[0059] A dye composition, which is assisted by an auxiliary agent in the field of dyes with the above-mentioned reactive red dye as an active component. The finished dye product made by the reactive red dye of the present invention can exist as solid particles, powder or solution. The active component can only include one of the above-mentioned reactive red dyes, or can include two or more reactive red dyes. The auxiliary agent in the field of dyes includes but is not limited to common cosolvents, alkali-resistant agent FSN, dust-proofing agent (for example polyoxyethylene ether oleate mixture), filler, sodium sulfate, stabilizer or electrolyte salts etc. in commercial dyes, wherein the electrolyte salts are as sodium chloride, potassium chloride, sodium sulfate or potassium sulfate.

[0060] The reactive red dye disclosed in the present invention can be applied to the printing and dyeing of fiber fabrics, in particular to the exhaust dyeing, pad dyeing or inkjet printing of cotton, linen, cellulose fiber, polyamide fiber, protein fiber or rayon fiber.

[0061] Adopt the technical scheme of the present invention, the advantages are as follows:

[0062] The invention provides a multi-purpose, high-performance, functional and environmentally friendly reactive red dye, which solves the common usage defects of existing reactive red dyes, such as low solubility, poor salt and alkali resistance, poor levelness and reproducibility, and low fixation rate improvement, making them difficult to apply to low-salt, small bath ratio dyeing and low-urea printing, and easily causing color flocculence, staining, poor water fastness and wet treatment fastness after dyeing. The multi-purpose, high-performance, functional and environmentally friendly reactive red dye has high solubility, good fixation rate, salt and alkali resistance stability and color fastness, high stability after dyeing, and bright color. It can be widely used in dip dyeing, pad dyeing and inkjet printing of cotton, linen, cellulose fiber, protein fiber or artificial cotton fiber fabrics, has low production cost, and can be promoted and applied on a large scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 This is the liquid chromatogram of the alkali-resistant agent FSN. DETAILED DESCRIPTION

[0064] The present invention can be better understood according to the following examples. However, it is easy for those skilled in the art to understand that the contents described in the examples are only used to illustrate the present invention, and should not and will not limit the present invention described in detail in the claims.

[0065] The reactive brilliant blue dye of the present invention is further described by the following examples, but these examples do not constitute any limitation to the present invention.

[0066] Example 1

[0067] (1) 0.1 mol of compound 1 was dissolved in a sodium bicarbonate solution, the pH of which was adjusted to 5.5-6.8, and the solution was added to an aqueous solution containing 0.12 mol of compound 2. A primary condensation reaction was carried out at a temperature of 0-5°C to prepare compound II-1, thereby obtaining a primary condensation solution I.

[0068] (2) Dispersing 0.12 mol of compound 3 in water, adding hydrochloric acid, and after mixing evenly, adjusting the temperature of the resulting mixture to 0-5°C, then adding sodium nitrite, and carrying out a diazotization reaction while maintaining the temperature at 0-5°C to obtain diazo solution I;

[0069] (3) The diazo solution I obtained in step (2) and the primary condensation solution I obtained in step (1) are uniformly mixed, the pH value thereof is adjusted to 6.0-6.5, and a coupling reaction is carried out at a temperature of 10-15° C. to prepare compound II-1a, thereby obtaining a coupling reaction solution I;

[0070] (4) 0.1 mol of compound 4 was dissolved in an alkaline solution, the pH of which was adjusted to 5.5-6.8, and the solution was added to an aqueous solution containing 0.12 mol of compound 2. A primary condensation reaction was carried out at a temperature of 0-5°C to prepare compound II-2, thereby obtaining a primary condensation solution II.

[0071] (5) Dispersing 0.12 mol of compound 5 in water, adding hydrochloric acid, and after mixing evenly, adjusting the temperature of the resulting mixture to 0-5°C, then adding sodium nitrite, and carrying out a diazotization reaction while maintaining the temperature at 0-5°C to obtain diazo solution II;

[0072] (6) Evenly mixing the diazo solution II obtained in step (5) and the primary condensation solution II obtained in step (4), adjusting the pH value to 6.0-6.5, and performing a coupling reaction at a temperature of 10-15° C. to prepare compound II-2a, thereby obtaining a coupling reaction solution II;

[0073] (7) The coupling reaction solution I obtained in step (3) and the coupling reaction solution II obtained in step (6) are mixed uniformly, 0.12 mol of hydroxyethylethylenediamine is added, the pH value thereof is adjusted to 6.5-7.5, and a secondary condensation reaction is carried out at a temperature of 40-50° C. to obtain a finished dye solution, which is dried to obtain a reactive red dye of formula I, and dried to obtain a reactive red dye of formula I. The synthetic route thereof is as follows:

[0074]

[0075]

[0076] The mass spectrum data of compound 1 are as follows: MS (EI, m / z): 1471.01 [MH] - .

[0077] Example 2

[0078] Referring to the preparation method in Example 1, sodium hydroxide solution was added to the obtained dye product solution to adjust its pH to 9.0. A hydrolysis reaction was carried out at 25° C. The obtained reaction solution was dried to obtain the reactive brilliant blue dye shown in Formula 8. The synthetic route thereof is as follows:

[0079]

[0080] The mass spectrum data of compound 19 are as follows: MS (EI, m / z): 1351.94 [MH] - .

[0081] Compounds 2-18 and 20-36 were prepared by referring to the methods in Examples 1 and 2. Due to limited space, the detailed preparation methods are not disclosed in detail. Instead, the structures of the compounds and the corresponding mass spectrometry data are simply disclosed.

[0082] Example 3

[0083]

[0084] The mass spectrum data of compound 2 are as follows: MS (EI, m / z): 1471.02 [MH] - .

[0085] Example 4

[0086]

[0087] The mass spectrum data of compound 20 are as follows: MS (EI, m / z): 1351.92 [MH] - .

[0088] Example 5

[0089]

[0090] The mass spectrum data of compound 3 are as follows: MS (EI, m / z): 1573.05 [MH] - .

[0091] Example 6

[0092]

[0093] The mass spectrum data of compound 21 are as follows: MS (EI, m / z): 1454.01 [MH] - .

[0094] Example 7

[0095]

[0096] The mass spectrum data of compound 4 are as follows: MS (EI, m / z): 1573.08 [MH] - .

[0097] Example 8

[0098]

[0099] The mass spectrum data of compound 22 are as follows: MS (EI, m / z): 1454.04 [MH] - .

[0100] Example 9

[0101]

[0102] The mass spectrum data of compound 5 are as follows: MS (EI, m / z): 1573.06 [MH] - .

[0103] Example 10

[0104]

[0105] The mass spectrum data of compound 23 are as follows: MS (EI, m / z): 1454.02 [MH] - .

[0106] Example 11

[0107]

[0108] The mass spectrum data of compound 6 are as follows: MS (EI, m / z): 1675.09 [MH] - .

[0109] Example 12

[0110]

[0111] The mass spectrum data of compound 24 are as follows: MS (EI, m / z): 1556.03 [MH] - .

[0112] Example 13

[0113]

[0114] The mass spectrum data of compound 7 are as follows: MS (EI, m / z): 1501.03 [MH] - .

[0115] Example 14

[0116]

[0117] The mass spectrum data of compound 25 are as follows: MS (EI, m / z): 1381.99 [MH] - .

[0118] Example 15

[0119]

[0120] The mass spectrum data of compound 8 are as follows: MS (EI, m / z): 1501.05 [MH] - .

[0121] Example 16

[0122]

[0123] The mass spectrum data of compound 26 are as follows: MS (EI, m / z): 1382.03 [MH] - .

[0124] Example 17

[0125]

[0126] The mass spectrum data of compound 9 are as follows: MS (EI, m / z): 1603.08 [MH] - .

[0127] Example 18

[0128]

[0129] The mass spectrum data of compound 27 are as follows: MS (EI, m / z): 1484.04 [MH] - .

[0130] Example 19

[0131]

[0132] The mass spectrum data of compound 10 are as follows: MS (EI, m / z): 1471.03 [MH] - .

[0133] Example 20

[0134]

[0135] The mass spectrum data of compound 28 are as follows: MS (EI, m / z): 1351.97 [MH] - .

[0136] Example 21

[0137]

[0138] The mass spectrum data of compound 21 are as follows: MS (EI, m / z): 1471.04 [MH] - .

[0139] Example 22

[0140]

[0141] The mass spectrum data of compound 29 are as follows: MS (EI, m / z): 1351.96 [MH] - .

[0142] Example 23

[0143]

[0144] The mass spectrum data of compound 12 are as follows: MS (EI, m / z): 1573.05 [MH] - .

[0145] Example 24

[0146]

[0147] The mass spectrum data of compound 30 are as follows: MS (EI, m / z): 1454.06 [MH] - .

[0148] Example 25

[0149]

[0150] The mass spectrum data of compound 13 are as follows: MS (EI, m / z): 1521.07 [MH] - .

[0151] Example 26

[0152]

[0153] The mass spectrum data of compound 31 are as follows: MS (EI, m / z): 1402.03 [MH] - .

[0154] Example 27

[0155]

[0156] The mass spectrum data of compound 14 are as follows: MS (EI, m / z): 1521.05 [MH] - .

[0157] Example 28

[0158]

[0159] The mass spectrum data of compound 32 are as follows: MS (EI, m / z): 1402.05 [MH] - .

[0160] Example 29

[0161]

[0162] The mass spectrum data of compound 15 are as follows: MS (EI, m / z): 1623.09 [MH] - .

[0163] Example 30

[0164]

[0165] The mass spectrum data of compound 33 are as follows: MS (EI, m / z): 1504.06 [MH] - .

[0166] Example 31

[0167]

[0168] The mass spectrum data of compound 16 are as follows: MS (EI, m / z): 1623.08 [MH] - .

[0169] Example 32

[0170]

[0171] The mass spectrum data of compound 34 are as follows: MS (EI, m / z): 1504.08 [MH] - .

[0172] Example 33

[0173]

[0174] The mass spectrum data of compound 17 are as follows: MS (EI, m / z): 1623.10 [MH] - .

[0175] Example 34

[0176]

[0177] The mass spectrum data of compound 35 are as follows: MS (EI, m / z): 1504.06 [MH] - .

[0178] Example 35

[0179]

[0180] The mass spectrum data of compound 18 are as follows: MS (EI, m / z): 1725.13 [MH] - .

[0181] Example 36

[0182]

[0183] The mass spectrum data of compound 18 are as follows: MS (EI, m / z): 1606.09 [MH] - .

[0184] The structural formula of dye A of Comparative Example 1 is as follows:

[0185]

[0186] The structural formula of comparative example 2 dye B is as follows:

[0187]

[0188] Printing and dyeing experiment instructions

[0189] According to the test standards for solubility of water-soluble dyes in GB / T 3671.1-1996, salt and alkali stability in GB / T 29597-2013, color fastness in GB / T 2391, washing fastness in GB / T3921-2008, and light fastness in GB / T8427-2008, the reactive red dyes 1-18 prepared in Examples 1-36, as well as dyes 1-18 with 10% alkali resistance agent FSN added thereto, and the dyes in Comparative Examples 1-2 were tested for dyeing performance. The results are shown in Table 1.

[0190] Table 1 Printing and dyeing test results

[0191]

[0192]

[0193]

[0194] The printing and dyeing test results in Table 1 show that the inkjet printing reactive red dyes 1-36 disclosed in Examples 1-36 of the present invention exhibit excellent light fastness, water fastness, solubility, salt-alkali stability, and color fixation rate. In particular, their solubility is significantly superior to that of dyes A and B in the comparative examples. These dyes can be used in fiber textile printing and dyeing, particularly in exhaust dyeing, pad dyeing, or inkjet printing of cotton, linen, cellulose fibers, protein fibers, polyamide fibers, or rayon fibers. The inkjet printing reactive brilliant blue dyes 1-36 disclosed in the present invention exhibit significantly improved solubility, salt-alkali stability, and color fixation rate when 10% of the alkali-resistant agent FSN is added.

[0195] The synthetic route of the alkali-resistant agent FSN mentioned in the present invention is as follows:

[0196]

[0197] The preparation method of alkali-resistant agent FSN comprises the following steps:

[0198] (1) Sulfonation reaction: Add 0.1 mol of methylnaphthalene and 0.1 mol of naphthalene to a reaction flask, mix well, and heat to 110°C to dissolve the mixture completely. Then heat to 130°C and dropwise add a sulfuric acid solution containing 0.28 mol of sulfuric acid. After the addition is complete, heat to 160°C and keep warm for 3 hours. Sample the sulfonated product and measure the acidity at the endpoint, which is 29-32%. Then cool to 110°C.

[0199] (2) Hydrolysis reaction: After the sulfonation is completed, water is added dropwise. After the addition is completed, the temperature is raised to 120°C and the reaction is carried out for 30 minutes. The acid value of the sample is measured to be 25-28%, and the temperature is lowered by 100°C.

[0200] (3) Condensation reaction: 0.12 mol of 37% formaldehyde solution was added dropwise to the reaction solution obtained in step (2), and the condensation reaction was carried out at a temperature of 105-110°C for 6 hours. After the reaction was completed, water was added and the temperature was lowered by 60°C.

[0201] (4) Neutralization reaction: add 0.18 mol of 30% sodium hydroxide solution to the reaction solution obtained in step (3), adjust the pH to 6.0-6.5 with calcium hydroxide solution, filter to remove impurities, and dry to obtain the alkali-resistant agent FSN. Its liquid chromatogram is as follows: Figure 1 As shown, the main peaks are located at 4.755 min and 6.023 min.

[0202] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that it is still possible to modify the technical solutions described in the aforementioned embodiments, or to make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A reactive red dye having formula I, characterized in that in, R1 represents H or SO3M; R2 represents H or SO3M; and R1 and R2 are not H at the same time; Ring A represents a phenyl group or a naphthyl group; R3 represents H, SO3M, C1-C4 alkyl or C1-C4 alkoxy; R4 represents SO2CH2CH2OSO3M; M represents H, Na or K.

2. Reactive red dye according to claim 1, is characterized in that, R3 represents H, SO3Na, methyl, ethylmethoxy or ethoxy.

3. Reactive red dye according to claim 1, is characterized in that, R3 represents H, SO3Na or methoxy.

4. Reactive red dye according to claim 1, is characterized in that, M stands for Na.

5. The reactive red dye according to claim 1, wherein The dye is selected from the following compounds:

6. A method for preparing the reactive red dye according to claim 1, characterized in that, The synthetic route is as follows: Wherein, M represents Na or K.

7. The preparation method of reactive red dye according to claim 6, wherein It includes the following steps: (1) Compound 1 is dissolved in an alkaline solution, the pH of which is adjusted to 5.5-6.8, and then added to an aqueous solution of Compound 2. A primary condensation reaction is carried out at a temperature of 0-5°C to prepare Compound II-1, thereby obtaining a primary condensation solution I. (2) Compound 3 is dispersed in water, hydrochloric acid is added, and after mixing, the temperature of the resulting mixture is adjusted to 0-5°C, and sodium nitrite is added, and a diazotization reaction is carried out while maintaining the temperature at 0-5°C to obtain diazo solution I; (3) The diazo solution I obtained in step (2) and the primary condensation solution I obtained in step (1) are uniformly mixed, the pH value thereof is adjusted to 6.0-6.5, and a coupling reaction is carried out at a temperature of 10-15° C. to prepare compound II-1a, thereby obtaining a coupling reaction solution I; (4) Compound 4 is dissolved in an alkaline solution, the pH of which is adjusted to 5.5-6.8, and then added to an aqueous solution of Compound 2. A primary condensation reaction is carried out at a temperature of 0-5°C to prepare Compound II-2, thereby obtaining a primary condensation solution II. (5) Dispersing compound 5 in water, adding hydrochloric acid, and after mixing evenly, adjusting the temperature of the resulting mixture to 0-5°C, then adding sodium nitrite, and performing a diazotization reaction while maintaining the temperature at 0-5°C to obtain diazo solution II; (6) Evenly mixing the diazo solution II obtained in step (5) and the primary condensation solution II obtained in step (4), adjusting the pH value to 6.0-6.5, and performing a coupling reaction at a temperature of 10-15° C. to prepare compound II-2a, thereby obtaining a coupling reaction solution II; (7) The coupling reaction solution I obtained in step (3) and the coupling reaction solution II obtained in step (6) are mixed uniformly, hydroxyethylethylenediamine is added, the pH value thereof is adjusted to 6.5-7.5, and a secondary condensation reaction is carried out at a temperature of 40-50° C. to obtain a finished dye solution, which is then dried to obtain the reactive red dye represented by formula I.

8. The preparation method of reactive red dye according to claim 7, wherein In step (1), the alkaline solution is sodium hydroxide solution, sodium bicarbonate solution, potassium hydroxide solution or potassium bicarbonate solution; the molar ratio of compound 1 to compound 2 is 1:1.1-1.5; In step (4), the alkaline solution is sodium hydroxide solution, sodium bicarbonate solution, potassium hydroxide solution or potassium bicarbonate solution; the molar ratio of compound 4 to compound 2 is 1:1.1-1.

5.

9. The preparation method of reactive red dye according to claim 8, wherein In step (1), the molar ratio of compound 1 to compound 2 is 1:1.2; in step (4), the molar ratio of compound 4 to compound 2 is 1:1.

2.

10. Use of the reactive red dye according to any one of claims 1 to 5 in dyeing and printing fiber fabrics.

11. The use according to claim 10, wherein the reactive red dye is used in exhaust dyeing, pad dyeing or inkjet printing of cotton, linen, cellulose fiber, polyamide fiber, protein fiber or rayon fiber.

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