Purple sun-fast reactive dye and preparation method thereof

Abstract

This application discloses a purple sun-fast reactive dye and its preparation method, relating to the field of reactive dyes. The general structural formula is as follows: Formula 1: #imgabs0# Formula 2: #imgabs1# wherein R1 is a C1-C8 linear alkyl group; R2, R3, R4, and R5 are all selected from the group consisting of -H, -SO3M, -SO2C2H4OSO3M, -CH3, and -NO2; and M is Na, K, or Li. This application improves the color fixation and sun-fastness properties of the reactive dye.

Description

Technical Field

[0001] The present application relates to the field of reactive dyes, and in particular to a purple sun-fast reactive dye and a preparation method thereof. Background Art

[0002] Reactive dyes, also known as reactive dyes, contain active groups that react with hydroxyl groups in cellulose and amino groups in protein fibers. During dyeing, they form covalent bonds with the fibers, creating "dye-fiber" compounds. Reactive dyes offer bright colors, excellent levelness, simple dyeing methods, high color fastness, a comprehensive color spectrum, and low cost. They are primarily used for dyeing and printing fibers such as cotton, linen, viscose, silk, and wool, as well as their blends.

[0003] Currently, most reactive dyes use cyanuric chloride and para-esters or para-ester derivatives as active groups, but their light fastness is low. Therefore, it is particularly important to develop a light-fast reactive dye. Summary of the Invention

[0004] In order to improve the problem of poor light-fastness of reactive dyes, the present application provides a purple light-fast reactive dye and a preparation method thereof.

[0005] In the first aspect, the present application provides a purple sun-fast reactive dye using the following technical solution:

[0006] A purple sun-fast reactive dye, having the following general structural formula:

[0007] Formula 1:

[0008]

[0009] Formula 2:

[0010]

[0011] Wherein, R1 is a straight-chain alkyl group of C1-C8; R2, R3, R4, and R5 are all one of -H, -SO3M, -SO2C2H4OSO3M, -CH3, and -NO2; and M is Na, K, or Li.

[0012] Preferably, R1 is -CH2CH2CH2, -CH2CH2 or -CH2CH2CH2CH2.

[0013] Preferably, R1 is -CH2CH2CH2.

[0014] Preferably, R2 and R4 are SO3M or H; R3 and R5 are H; and M is Na.

[0015] Preferably, the specific structural formula is one of the following:

[0016] Formula 3:

[0017]

[0018] Formula 4:

[0019]

[0020] Formula 5:

[0021]

[0022] By adopting the above technical solution, triphendioxazine is used as the blue first matrix, and the coupling product of sulfonated tobiasic acid, tobiasic acid or p-aminobenzenesulfonic acid and 1-amino-8-naphthol 3,6-disulfonic acid is used as the red second matrix. The first matrix and the second matrix interact with each other, so that the dye is bright purple, and the color fixation rate reaches more than 84%. Various dyeing properties such as water fastness, friction fastness, and chlorine fastness are high, the solubility effect is good, and especially the light fastness reaches level 7. Nicotinic acid is used as the active group to replace the third chlorine atom of cyanuric chloride, which has stronger reaction activity and can be dyed at a medium temperature of 60 degrees. Under the combined effect, the color fixation effect of the dye is improved while various dyeing properties are excellent, especially the light fastness is improved.

[0023] In a second aspect, the present application provides a method for preparing a purple sun-fast reactive dye using the following technical solution:

[0024] A method for preparing a purple sun-fast reactive dye comprises the following steps:

[0025] a. Mix 1-amino-8-naphthol-3,6-disulfonic acid monosodium salt and water, adjust the pH, and obtain a dissolved product;

[0026] b) mixing cyanuric chloride beaten with an ice-water mixture with the dissolved product, adjusting the pH, and obtaining a condensed product;

[0027] c. Take sulfonated Tobias acid, Tobias acid or p-aminobenzenesulfonic acid and react with hydrochloric acid and sodium nitrite in sequence to prepare diazonium salt;

[0028] d: mixing the monocondensation product with the diazonium salt, adjusting the pH, and reacting to obtain a coupling product;

[0029] e) Mixing an aqueous solution of dibromotriphenyldioxazine with 1,3-propylenediamine, adjusting the pH, and reacting to obtain an alkylated product;

[0030] f: mixing the alkylation product and the coupling product, adjusting the pH, and reacting to obtain a dicondensation product;

[0031] g: mixing the dicondensation product with nicotinic acid, adjusting the pH, and reacting to obtain a purple sun-fast reactive dye.

[0032] Preferably, in step a, the mass ratio of 1-amino-8-naphthol-3,6-disulfonic acid monosodium salt to water is 1:(3-6).

[0033] In the step a, the mass ratio of the 1-amino-8-naphthol-3,6-disulfonic acid monosodium salt to water is 1:4.

[0034] Preferably, in step a, the pH is adjusted to 6.5-7.0.

[0035] Preferably, in the step b, the molar ratio of the cyanuric chloride to the 1-amino-8-naphthol-3,6-disulfonic acid monosodium salt in the dissolved product is (0.9-1.1):1.

[0036] Preferably, in the step b, the molar ratio of the cyanuric chloride to the 1-amino-8-naphthol-3,6-disulfonic acid monosodium salt in the dissolved product is 1:1.

[0037] Preferably, in the step b, cyanuric chloride beaten with an ice-water mixture is mixed with the dissolved product, the temperature is controlled at 5-10° C., the pH is adjusted to 3.0-4.0, and the reaction is maintained for 1.5-2.5 hours to obtain a condensed product.

[0038] Preferably, in step c, the molar ratio of the sulfonated Tobias acid, Tobias acid or p-aminobenzenesulfonic acid to the hydrochloric acid is 1:(0.5-1.1), and the molar ratio of the sulfonated Tobias acid, Tobias acid or p-aminobenzenesulfonic acid to the sodium nitrite is 1:(1.0-1.2).

[0039] Preferably, in step c, the molar ratio of the sulfonated Tobias acid, Tobias acid or p-aminobenzenesulfonic acid to the hydrochloric acid is 1:(0.5-1.0), and the molar ratio of the sulfonated Tobias acid, Tobias acid or p-aminobenzenesulfonic acid to the sodium nitrite is 1:(1.0-1.2).

[0040] Preferably, in step c, the molar ratio of the sulfonated Tobias acid, Tobias acid or p-aminobenzenesulfonic acid to the hydrochloric acid is 1:1, and the molar ratio of the sulfonated Tobias acid, Tobias acid or p-aminobenzenesulfonic acid to the sodium nitrite is 1:1.1.

[0041] Preferably, in step c, after the sulfonated Tobias acid, Tobias acid or p-aminobenzenesulfonic acid reacts with hydrochloric acid, the temperature is lowered to 0° C., and then sodium nitrite is added to react for 0.5-2 hours.

[0042] Preferably, in step c, the volume concentration of hydrochloric acid is 29-36%.

[0043] Preferably, in step c, the volume concentration of hydrochloric acid is 30%.

[0044] Preferably, in the step d, the diazonium salt is added to the condensation product, and the reaction is carried out at a temperature of 5-10° C. and a pH of 6.5-7.0 for 2.5-3.5 hours to obtain the coupling product.

[0045] Preferably, in the step e, the molar ratio of dibromotriphenyldioxazine to 1,3-propylenediamine is 1:(1.8-2.2).

[0046] Preferably, in the step e, the molar ratio of dibromotriphenyldioxazine to 1,3-propylenediamine is 1:2.

[0047] Preferably, in the step e, in the dibromotriphenyldioxazine solution, the weight ratio of the dibromotriphenyldioxazine to water is 1:(5-7).

[0048] Preferably, in the step e, in the dibromotriphenyldioxazine solution, the weight ratio of the dibromotriphenyldioxazine to water is 1:6.

[0049] Preferably, in the step e, the pH is adjusted to 3.0-4.0.

[0050] Preferably, the molar ratio of cyanuric chloride in step b to dibromotriphenyldioxazine in step e is (1.8-2.2):1.

[0051] Preferably, in the step f, the alkylation product is added to the coupling product, the pH is adjusted to 3.0-4.0, the temperature is raised to 40-50° C., and the reaction is maintained for 3.5-4.5 hours to obtain the dicondensation product.

[0052] Preferably, the molar ratio of dibromotriphenyldioxazine in step e to nicotinic acid in step g is 1:(2-3).

[0053] Preferably, the molar ratio of dibromotriphenyldioxazine in step e to nicotinic acid in step g is 1:(2-2.5).

[0054] Preferably, the molar ratio of dibromotriphenyldioxazine in step e to nicotinic acid in step g is 1:2.5.

[0055] Preferably, in step g, the dicondensation product is reacted with nicotinic acid The mixture was mixed, the temperature was controlled at 75-85° C., the pH was adjusted to 4.0-4.5, and the reaction was maintained for 5.5-6.5 hours to obtain a purple sun-fast reactive dye.

[0056] By adopting the above technical solution, triphendioxazine is introduced as the first matrix through dibromotriphendioxazine, and the second matrix is ​​obtained by coupling reaction of sulfonated tobiased acid, tobiased acid or p-aminobenzenesulfonic acid with 1-amino-8-naphthol 3,6-disulfonic acid. Under the combined effect of the first matrix and the second matrix, the dyeing performance is improved, the color fixation rate reaches 84%, and the light fastness reaches level 7, which improves the light resistance.

[0057] In a third aspect, the present application provides an application of a purple sun-fast reactive dye in dyeing cotton fibers and textiles thereof, using the following technical solution:

[0058] The invention discloses an application of a purple sun-fast reactive dye in dyeing cotton fiber and textiles thereof. The concentration of the purple sun-fast reactive dye is 0.5-12% (owf).

[0059] Preferably, the concentration of the purple sun-fast reactive dye is 0.5-10% (owf).

[0060] By adopting the above technical solution, when the concentration (owf) of the purple sun-fast reactive dye is (0.5-12%), the purple sun-fast reactive dye has a fixation rate of more than 84% and a light fastness of level 7 in cotton fibers and textiles thereof, thereby improving the color fixation effect and light fastness of the dye on cotton fibers and textiles.

[0061] In summary, this application includes at least one of the following beneficial technical effects:

[0062] 1. Triphenyldioxazine is used as the blue first matrix, and the coupling product of sulfonated tobiasic acid, tobiasic acid or p-aminobenzenesulfonic acid and 1-amino-8-naphthol 3,6-disulfonic acid is used as the red second matrix. The interaction between the first matrix and the second matrix makes the dye appear bright purple, and the color fixation rate reaches more than 84%. The dyeing properties such as water fastness, friction fastness, and chlorine fastness are high, the solubility effect is good, and especially the light fastness reaches level 7.

[0063] 2. Nicotinic acid is used as the active group to replace the third chlorine atom of cyanuric chloride, which makes the reaction more active and can be dyed at medium temperature at 60 degrees.

[0064] 3. Purple light-fast reactive dyes are used in the dyeing of cotton fibers and textiles. When the concentration (owf) is (0.5-12%), the color fixing effect and dyeing performance are greatly improved, with a color fixing rate of more than 84% and a light fastness of level 7. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 This is the synthesis route of the purple sun-fast reactive dye - Formula 3 in Example 1 of the present application. DETAILED DESCRIPTION

[0066] The present application is described in further detail below in conjunction with Examples. The following examples are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention. In the following examples, if specific conditions are not specified, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. The methods used are conventional methods well known in the art unless otherwise specified, and the consumables and reagents used are commercially available unless otherwise specified. Unless otherwise indicated, the professional and scientific terms used herein have the same meaning as those familiar to those skilled in the art. In addition, any method or material similar or equivalent to the described content may also be applied to the present invention.

[0067] The raw materials used in the examples can all be obtained commercially.

[0068] Example 1

[0069] Example 1 discloses a purple sun-fast reactive dye, which is prepared by the following steps:

[0070] Step a, dissolution: add water to 0.2 mol of 1-amino-8-naphthol-3,6-disulfonic acid monosodium salt and beat evenly, the weight ratio of 1-amino-8-naphthol-3,6-disulfonic acid monosodium salt to water is 1:4, and adjust the system pH to 6.5-7.0 with baking soda to obtain a dissolved product, the reaction formula is as follows:

[0071]

[0072] Step b, a condensation reaction: 0.2 mol of cyanuric chloride is slurried with an ice-water mixture for half an hour, the weight ratio of cyanuric chloride to the ice-water mixture is 1:5, to obtain a cyanuric chloride slurry, the dissolved product obtained in step a is added dropwise to the cyanuric chloride slurry, the temperature is controlled at 5-10°C, the pH of the system is adjusted to 3.0-4.0 with baking soda, and the reaction is maintained for 2 hours to obtain a condensation product. The reaction formula is as follows:

[0073]

[0074] Step c, diazo reaction: add 0.2 mol of hydrochloric acid (volume concentration is 30%) to 0.2 mol of sulfonated Tobias acid, stir evenly, cool to 0°C, and then add 0.22 mol of sodium nitrite after the reaction for 1 hour to obtain the diazonium salt. The reaction formula is as follows:

[0075]

[0076] Step d, coupling reaction: add the diazonium salt obtained in step c to the monocondensed product obtained in step b, control the temperature at 5-10°C, adjust the system pH to 6.5-7.0 with baking soda, and maintain the reaction for 3 hours to obtain a coupled product. The reaction formula is as follows:

[0077]

[0078] Step e, alkylation reaction: 0.1 mol of dibromotriphenyldioxazine was dissolved in water at a weight ratio of dibromotriphenyldioxazine to water of 1:6 to obtain a dibromotriphenyldioxazine aqueous solution, 0.2 mol of 1,3-propylenediamine was added, and the pH was adjusted to 3-4 with baking soda. The reaction was maintained for 3 hours to obtain an alkylated product. The reaction formula is as follows:

[0079]

[0080] Step f, dicondensation reaction: add the alkylation product obtained in step e to the coupling product obtained in step d, adjust the pH to 3.0-4.0 with baking soda, raise the temperature to 40-50° C., and maintain the reaction for 4 hours to obtain the dicondensation product. The reaction formula is as follows:

[0081]

[0082] Step g, tricondensation reaction: add 0.25 mol of nicotinic acid to the dicondensation product obtained in step f, adjust the pH to 4.0-4.5 with baking soda, raise the temperature to 75-85°C, and maintain the reaction for 6 hours to obtain a purple sun-fast reactive dye - Formula 3, the reaction formula is as follows:

[0083]

[0084] Purple sun-fast reactive dye - Synthesis route of formula 3 Figure 1 .

[0085] Example 2

[0086] Example 2 discloses a purple sun-fast reactive dye, which is prepared by the following steps:

[0087] Step a, dissolution: add water to 0.2 mol of 1-amino-8-naphthol-3,6-disulfonic acid monosodium salt and beat evenly, the weight ratio of 1-amino-8-naphthol-3,6-disulfonic acid monosodium salt to water is 1:4, and adjust the system pH to 6.5-7.0 with baking soda to obtain a dissolved product, the reaction formula is as follows:

[0088]

[0089] Step b, a condensation reaction: 0.2 mol of cyanuric chloride is slurried with an ice-water mixture for half an hour, the weight ratio of cyanuric chloride to the ice-water mixture is 1:5, to obtain a cyanuric chloride slurry, the dissolved product obtained in step a is added dropwise to the cyanuric chloride slurry, the temperature is controlled at 5-10°C, the pH of the system is adjusted to 3.0-4.0 with baking soda, and the reaction is maintained for 2 hours to obtain a condensation product. The reaction formula is as follows:

[0090]

[0091] Step c, diazo reaction: add 0.2 mol of hydrochloric acid (volume concentration is 30%) to 0.2 mol of Tobias' acid, stir evenly, cool to 0°C, and then add 0.22 mol of sodium nitrite after the reaction for 2 hours to obtain the diazonium salt. The reaction formula is as follows:

[0092]

[0093] Step d, coupling reaction: add the diazonium salt obtained in step c to the monocondensed product obtained in step b, control the temperature at 5-10°C, adjust the system pH to 6.5-7.0 with baking soda, and maintain the reaction for 3 hours to obtain a coupled product. The reaction formula is as follows:

[0094]

[0095] Step e, alkylation reaction: 0.1 mol of dibromotriphenyldioxazine was dissolved in water at a weight ratio of dibromotriphenyldioxazine to water of 1:6 to obtain a dibromotriphenyldioxazine aqueous solution, 0.2 mol of 1,3-propylenediamine was added, and the pH was adjusted to 3-4 with baking soda. The reaction was maintained for 3 hours to obtain an alkylated product. The reaction formula is as follows:

[0096]

[0097] Step f, dicondensation reaction: add the alkylation product obtained in step e to the coupling product obtained in step d, adjust the pH to 3.0-4.0 with baking soda, raise the temperature to 40-50° C., and maintain the reaction for 4 hours to obtain the dicondensation product. The reaction formula is as follows:

[0098]

[0099] Step g, tricondensation reaction: add 0.25 mol of nicotinic acid to the dicondensation product obtained in step f, adjust the pH to 4.0-4.5 with baking soda, raise the temperature to 75-85°C, and maintain the reaction for 6 hours to obtain a purple sun-fast reactive dye (Formula 4), the reaction formula is as follows:

[0100]

[0101] Example 3

[0102] Example 3 discloses a purple sun-fast reactive dye, which is prepared by the following steps:

[0103] Step a, dissolution: add water to 0.2 mol of 1-amino-8-naphthol-3,6-disulfonic acid monosodium salt and beat evenly, the weight ratio of 1-amino-8-naphthol-3,6-disulfonic acid monosodium salt to water is 1:4, and adjust the system pH to 6.5-7.0 with baking soda to obtain a dissolved product, the reaction formula is as follows:

[0104]

[0105] Step b, a condensation reaction: 0.2 mol of cyanuric chloride is slurried with an ice-water mixture for half an hour, the weight ratio of cyanuric chloride to the ice-water mixture is 1:5, to obtain a cyanuric chloride slurry, the dissolved product obtained in step a is added dropwise to the cyanuric chloride slurry, the temperature is controlled at 5-10°C, the pH of the system is adjusted to 3.0-4.0 with baking soda, and the reaction is maintained for 2 hours to obtain a condensation product. The reaction formula is as follows:

[0106]

[0107] Step c, diazo reaction: add 0.2 mol of hydrochloric acid (volume concentration is 30%) to 0.2 mol of p-aminobenzenesulfonic acid, stir evenly, cool to 0°C, and then add 0.22 mol of sodium nitrite after the reaction for 2 hours to obtain the diazonium salt. The reaction formula is as follows:

[0108]

[0109] Step d, coupling reaction: add the diazonium salt obtained in step c to the monocondensed product obtained in step b, control the temperature at 5-10°C, adjust the system pH to 6.5-7.0 with baking soda, and maintain the reaction for 3 hours to obtain a coupled product. The reaction formula is as follows:

[0110]

[0111] Step e, alkylation reaction: 0.1 mol of dibromotriphenyldioxazine was dissolved in water at a weight ratio of dibromotriphenyldioxazine to water of 1:6 to obtain a dibromotriphenyldioxazine aqueous solution, 0.2 mol of 1,3-propylenediamine was added, and the pH was adjusted to 3.0-4.0 with baking soda. The reaction was maintained for 3 hours to obtain an alkylated product. The reaction formula is as follows:

[0112]

[0113] Step f, dicondensation reaction: add the alkylation product obtained in step e to the coupling product obtained in step d, adjust the pH to 3.0-4.0 with baking soda, raise the temperature to 40-50° C., and maintain the reaction for 4 hours to obtain the dicondensation product. The reaction formula is as follows:

[0114]

[0115] Step g, tricondensation reaction: add 0.25 mol of nicotinic acid to the dicondensation product obtained in step f, adjust the pH to 4.0-4.5 with baking soda, raise the temperature to 75-85°C, and maintain the reaction for 6 hours to obtain a purple sun-fast reactive dye (Formula 5), ​​the reaction formula is as follows:

[0116]

[0117] Comparative Example 1

[0118] Comparative Example 1 selected Reactive Violet 5 commonly found on the market.

[0119] Experimental testing

[0120] Experiment 1: UV-visible absorption spectrum test

[0121] The purple sun-fast reactive dyes obtained in Examples 1-3 and Reactive Violet 5 from Comparative Example 1 were prepared into solutions at a concentration of 1 gram per 500 ml of water. Ultraviolet absorption spectra were measured at room temperature using a UV-visible photometer in the 200-800 nm wavelength range. The visible absorption spectra of each dye were measured by dissolving the purple sun-fast reactive dyes from Examples 1-3 and Reactive Violet 5 from Comparative Example 1 in aqueous solutions at a concentration of 1 ml per 100 ml. The molar extinction coefficients and absorption peak values ​​of the spectra are shown in Table 1.

[0122] Table 1:

[0123] Data Source Absorption peak value Molar extinction coefficient Example 1 570 415 Example 2 572 405 Example 3 568 411 Comparative Example 1 586 402

[0124] Referring to Table 1, the molar extinction coefficients of Examples 1-3 are higher than that of Comparative Example 1, indicating that at the same concentration, the dyeing depths of Examples 1-3 are higher than that of Comparative Example 1. In addition, the molar extinction coefficient of Example 1 is greater than the molar extinction coefficients of Examples 2 and 3, indicating that the dyeing effect of the purple sun-fast reactive dye - Formula 4 is better than the dyeing effects of the purple sun-fast reactive dye - Formula 5 and the purple sun-fast reactive dye - Formula 6.

[0125] Experiment 2: Dyeing experiment on cotton fabric

[0126] The purple sun-fast reactive dyes of Examples 1-3 and the reactive violet 5 of Comparative Example 1 were respectively prepared according to the following conditions: cotton fabric: 5 g, sodium sulfate concentration: 20 g / L, bath ratio: 1:20, soda ash adjusted pH = 8.0, dye concentration: 4% (owf); dyeing was carried out by a 60°C heating dyeing method, and cloth samples were obtained after post-treatment.

[0127] (1) According to the national standards, color fastness to rubbing GB / T 3920 2008 and color fastness to washing GB / T 3921 2008, the color fastness of the dyed cotton fabric samples was measured. The results are shown in Table 2.

[0128] Table 2: Color fastness of cotton fabric dyeing at a dye concentration of 4% (owf)

[0129]

[0130] Referring to the data in Table 2, the purple sun-fast reactive dyes prepared in Examples 1-3 have slightly better washing fastness, rubbing fastness and solubility than the traditional reactive violet 5 dye in Comparative Example 1; the purple sun-fast reactive dyes prepared in Examples 1-3 have a light fastness far exceeding that of the reactive violet 5 dye in Comparative Example 1; and the purple sun-fast reactive dye - Formula 3 prepared in Example 1 has a light fastness of grade 7, which is better than the light fastness of the purple sun-fast reactive dye - Formula 4 prepared in Example 2 and the purple sun-fast reactive dye - Formula 5 prepared in Example 3.

[0131] (2) The fabric sample after dyeing in Example 1 was used as the standard sample, and the fabric samples after dyeing in Example 2, Example 3 and Comparative Example 1 were used as the test samples. The colors were measured on a colorimeter. The results are shown in Table 3.

[0132] Table 3:

[0133] Data Source Spectrophotometry strength Total color difference Beauty Value Red-green difference Huang Lancha Example 2 98％ 95％ 1.021 -0.422 -0.135 -0.444 Example 3 90％ 89％ 1.128 0.335 0.256 0.325 Comparative Example 1 86％ 84％ 3.251 -0.425 1.523 -2.106

[0134] Referring to Table 3, it can be seen that, using the fabric sample dyed with the purple light-fast reactive dye provided in Example 1 as a standard sample, the spectral distribution of Examples 2-3 all reached above 90%, the intensity reached above 89%, and the total color difference was around 1, while the spectral distribution of Comparative Example 1 was less than 90%, the intensity was 84%, and the total color difference was as high as 3.251. This indicates that the dyeing effects of the purple light-fast reactive dye - Formula 3, the purple light-fast reactive dye - Formula 4, and the purple light-fast reactive dye - Formula 5 are superior to the dyeing effect of Reactive Violet 5, and the dyeing effects of the purple light-fast reactive dye - Formula 3 and the purple light-fast reactive dye - Formula 4 are superior to the dyeing effects of the purple light-fast reactive dye - Formula 5.

[0135] Experiment 3: Dyeing experiment on cotton fabric

[0136] The purple light-fast reactive dyes in Examples 1-3 and the reactive violet 5 in Comparative Example 1 were respectively prepared according to the following conditions: 5 g of cotton fabric, 20 g / L of sodium sulfate, a bath ratio of 1:20, and soda ash were used to adjust the pH to 8.0, and the dye concentration was 0.5-12% (owf); dyeing was performed using a 60°C temperature rising dyeing method, and then the color fixation rate was determined. The color fixation rate test results are shown in Table 4.

[0137] Table 4: Fixation rate of dyes on cotton fabrics

[0138]

[0139] Referring to Table 4, the purple sun-fast reactive dyes provided in Examples 1-3 achieved a fixation rate of over 84% at a concentration of (0.5-12)% (owf) on cotton fabric, while the Reactive Violet 5 of Comparative Example 1 achieved a maximum fixation rate of only 81% at a concentration of (0.5-12)% (owf) on cotton fabric. In particular, the purple sun-fast reactive dye (Formula 3) prepared in Example 1 achieved a fixation rate that was (9-14)% higher than that of the conventional Reactive Violet 5 at a concentration of (0.5-12)% (owf) on cotton fabric, demonstrating excellent fixation effects.

[0140] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A purple sun-fast reactive dye, characterized in that: Its general structural formula is as follows: Formula 1: Formula 2: Wherein, R1 is a straight-chain alkyl group of C1-C8; R2, R3, R4, and R5 are all one of -H, -SO3M, -SO2C2H4OSO3M, -CH3, and -NO2; and M is Na, K, or Li.

2. A purple sun-fast reactive dye according to claim 1, characterized in that: Its specific structural formula is as follows: Formula 3: Formula 4: Formula 5:

3. A method for preparing the purple sun-fast reactive dye according to any one of claims 1 to 2, characterized in that: The following steps are involved: a. Mix 1-amino-8-naphthol-3,6-disulfonic acid monosodium salt and water, adjust the pH, and obtain a dissolved product; b) mixing cyanuric chloride beaten with an ice-water mixture with the dissolved product, adjusting the pH, and obtaining a condensed product; c. Take sulfonated Tobias acid, Tobias acid or p-aminobenzenesulfonic acid and react with hydrochloric acid and sodium nitrite in sequence to prepare diazonium salt; d: mixing the monocondensation product with the diazonium salt, adjusting the pH, and reacting to obtain a coupling product; e: Mix the aqueous solution of raw material A with 1,3-propylenediamine, adjust the pH, and react to obtain an alkylation product, wherein the chemical formula of raw material A is: f: mixing the alkylation product and the coupling product, adjusting the pH, and reacting to obtain a dicondensation product; g: mixing the dicondensation product with nicotinic acid, adjusting the pH, and reacting to obtain a purple sun-fast reactive dye.

4. The method for preparing a purple sun-fast reactive dye according to claim 3, wherein: In the step a, the mass ratio of the 1-amino-8-naphthol-3,6-disulfonic acid monosodium salt to water is 1:(3-6).

5. The method for preparing a purple sun-fast reactive dye according to claim 3, wherein: In the step b, the molar ratio of the cyanuric chloride to the 1-amino-8-naphthol-3,6-disulfonic acid monosodium salt in the dissolved product is (0.9-1.1):

1.

6. The method for preparing a purple sun-fast reactive dye according to claim 3, wherein: In step c, the molar ratio of the sulfonated Tobias acid, Tobias acid or p-aminobenzenesulfonic acid to the hydrochloric acid is 1:(0.5-1.0), and the molar ratio of the sulfonated Tobias acid, Tobias acid or p-aminobenzenesulfonic acid to the sodium nitrite is 1:(1.0-1.2).

7. The method for preparing a purple sun-fast reactive dye according to claim 3, wherein: In the step e, the molar ratio of the raw material A to the 1,3-propylenediamine is 1:(1.8-2.2).

8. The method for preparing a purple sun-fast reactive dye according to claim 3, wherein: The molar ratio of cyanuric chloride in step b to raw material A in step e is (1.8-2.2):

1.

9. The method for preparing a purple sun-fast reactive dye according to claim 3, wherein: The molar ratio of the raw material A in the step e to the nicotinic acid in the step g is 1:(2-2.5).

10. Use of the purple sun-fast reactive dye according to any one of claims 1 to 2 in dyeing cotton fibers and textiles thereof, characterized in that: The concentration of the purple light-fast reactive dye is 0.5-12% (owf).

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