High color fastness reactive dye, preparation method, dyeing process and application

Abstract

The present application relates to the technical field of textile dyes, and discloses a reactive dye with high color fastness, a preparation method, a dyeing process and application thereof. The dye takes azo dyes containing ethylene sulfone sulfate reactive groups as the main body, and comprises a composite dispersion stabilizer composed of a comb-shaped polycarboxylate dispersant, an organic polyphosphonic acid chelating agent and a fatty alcohol polyoxyethylene ether wetting agent. The components are mixed, stirred and spray dried, and then the dyeing is carried out under specific hard water conditions, followed by fixation, dyeing, color setting and post-treatment. The wetting agent ensures rapid wetting of the dye, the chelating agent effectively eliminates the interference of metal ions in hard water, and the dispersant provides persistent steric hindrance stability. The synergistic effect of the components improves the solubility and stability of the dye in hard water, reduces the flocculation rate, reduces the generation of color spots and color stains on the surface of the dyed fabric, improves the dyeing uniformity, and obtains better product quality.

Description

Technical Field

[0001] This invention belongs to the field of textile dye technology, specifically relating to a high color fastness reactive dye, its preparation method, dyeing process, and application. Background Technology

[0002] In the industrial dyeing process of reactive dyes, the first step is to completely dissolve the powdered dye in the dye bath to form a uniform and stable dye solution. This is a fundamental prerequisite for ensuring uniform and thorough dyeing in subsequent processes and avoiding quality defects such as color spots and stains. Therefore, the key indicators for ensuring the stable application of fuel products are good solubility and solution storage stability.

[0003] However, in practical applications, it has been found that existing conventional reactive dyes have insufficient stability in the chemical preparation process. Especially when using production water with high hardness, or when improper water temperature control or excessively rapid addition of dyes during the chemical preparation process leads to excessively high local concentrations, dye molecules are prone to combining with metal ions such as calcium and magnesium in the water, or to agglomeration and flocculation due to intermolecular forces.

[0004] To avoid this problem, dyeing and printing plants typically need to take strict preventative measures, such as softening production water, developing detailed chemical processing procedures, and filtering the dye liquor after chemical processing. While these measures can alleviate the problem to some extent, they increase production costs and operational complexity, and are highly dependent on worker experience, which can easily lead to fluctuations in product quality.

[0005] Once dye flocculation occurs, the resulting tiny aggregates cannot penetrate into the fibers and will eventually adhere to the fabric surface, forming difficult-to-repair color spots and stains, leading to a decline in product quality and causing economic losses. Moreover, the flocculated material can easily clog the dyeing equipment pipelines, increasing maintenance costs. Summary of the Invention

[0006] The purpose of this invention is to provide a reactive dye with high color fastness, a preparation method, a dyeing process, and an application, so as to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, according to a first aspect of the present invention, a high-colorfastness reactive dye is provided, comprising the following components based on the total weight of the reactive dye:

[0008] The reactive dye body comprises 85.0 wt% to 95.5 wt%, wherein the reactive dye body is an azo dye containing vinyl sulfone sulfate reactive groups;

[0009] 4.5wt%-15.0wt% of a composite dispersion stabilizer;

[0010] The composite dispersion stabilizer is composed of the following components:

[0011] 3.0wt%-8.0wt% comb-type polycarboxylate dispersant;

[0012] 0.5wt%-2.0wt% of organic polyphosphonic acid chelating agents;

[0013] 1.0wt%-3.0wt% of fatty alcohol polyoxyethylene ether wetting agents.

[0014] Preferably, the comb-type polycarboxylate dispersant is sodium maleic acid-acrylic acid copolymer.

[0015] Preferably, the organic polyphosphonic acid chelating agent is at least one of diethylenetriaminepentamethylphosphonic acid or hydroxyethylidene diphosphonic acid.

[0016] Preferably, the fatty alcohol polyoxyethylene ether wetting agent is a JFC penetrant.

[0017] According to a second aspect of the present invention, a method for preparing the aforementioned high color fastness reactive dye is provided, comprising the following steps:

[0018] A: Mix the reactive dye bulk with comb-type polycarboxylate dispersant, organic polyphosphonic acid chelating agent and fatty alcohol polyoxyethylene ether wetting agent evenly;

[0019] B: Stir at a temperature of 40℃ to 60℃ for 0.5 hours to 2 hours;

[0020] C: Spray drying is performed to obtain a reactive dye composition powder with high color fastness.

[0021] According to a third aspect of the present invention, a process for dyeing cellulose fiber materials using the aforementioned high color fastness reactive dye is provided, comprising the following steps:

[0022] S1: Dissolve the active dye composition in water with a hardness of not more than 250 ppm (calculated as calcium carbonate) at a dissolution temperature of 25°C to 45°C to obtain a dye solution.

[0023] S2: Immerse the cellulose fiber material in the dye solution for dyeing. The dyeing temperature is 40°C to 60°C, and the dyeing time is 10 minutes to 30 minutes.

[0024] S3: Add alkali to fix the color. The fixing temperature is 60℃ to 70℃, the fixing pH value is 10.5 to 11.5, and the fixing time is 30 minutes to 60 minutes.

[0025] S4: Perform water washing, soap washing and post-treatment.

[0026] According to a fourth aspect of the invention, the application of the high color fastness reactive dye in the dyeing of cellulosic fiber materials is provided.

[0027] Preferably, the cellulose fiber material is cotton, linen, viscose fiber, or a blend thereof.

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] (1) By using a composite dispersion stabilizer composed of comb-type polycarboxylate dispersant, organic polyphosphonic acid chelating agent and fatty alcohol polyoxyethylene ether wetting agent, the wetting agent promotes rapid wetting of dye, the chelating agent preferentially integrates calcium and magnesium ions in water, and the dispersant provides steric hindrance stability, thereby improving the solubility stability of reactive dyes under hard water conditions, effectively reducing the flocculation rate and particle size distribution of dye solution, thus solving the problem of color spots on fabrics caused by dye instability.

[0030] (2) By improving the uniformity of dye dispersion in the dye bath, the amount of dye aggregates is significantly reduced, thereby avoiding the deposition of insoluble particles on the fiber surface, reducing the formation of color spots and stains on the surface of dyed fabrics, and promoting the uniform distribution of dye on the fiber, resulting in a dyeing effect with smaller color difference, thus improving the quality of the product.

[0031] (3) By optimizing the dispersion stability of dyes, this invention reduces the occurrence of dye floating, making it easier to completely remove these floating colors in the subsequent soaping process. Thus, without changing the dye molecular structure, it improves the wash fastness and wet rubbing fastness of the dyed finished products, making the fabric products less prone to fading and improving product quality. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0033] Example 1

[0034] A reactive dye with high color fastness, based on the total weight of the reactive dye, is composed of the following components:

[0035] 90.0 wt% of reactive dye body, wherein the reactive dye body is CI Reactive Red 195, a typical azo dye containing vinyl sulfone sulfate reactive groups.

[0036] 10.0wt% of a composite dispersion stabilizer;

[0037] The composite dispersion stabilizer is composed of the following components:

[0038] 5.0 wt% comb-type polycarboxylate dispersant, specifically sodium salt of maleic acid-acrylic acid copolymer, with a solid content of 40%).

[0039] 1.5 wt% of an organic polyphosphonic acid chelating agent, specifically diethylenetriaminepentamethylenephosphonic acid (DTPMP);

[0040] 3.5 wt% of fatty alcohol polyoxyethylene ether wetting agent, specifically JFC penetrant.

[0041] A method for preparing reactive dyes with high color fastness includes the following steps:

[0042] A. Weigh 1000 grams of the synthesized and filtered CI Reactive Red 195 dye wet cake (dry content is 90%, i.e., contains 900 grams of dry dye body) and place it in a mixing vessel.

[0043] B. Add 125g of sodium maleic acid-acrylic acid copolymer (50g dry weight) with a solid content of 40%, 15g of DTPMP, and 35g of JFC penetrant to the mixing vessel in sequence.

[0044] C. Start stirring and heat the mixture to 50°C. Continue stirring at this temperature for 1 hour to ensure that all components are fully and evenly mixed. Then, send the uniform slurry into a centrifugal spray drying tower for drying. The inlet air temperature is controlled at 180°C and the outlet air temperature is controlled at 85°C to obtain a high-color-fastness reactive dye product in red powder form.

[0045] A process for dyeing cellulose fiber materials using reactive dyes with high color fastness includes the following steps:

[0046] S1. Weigh 10 grams of the reactive dye prepared in this example and slowly add it to a dye cup containing 990 ml of hard water (hardness of 250 ppm CaCO3) at 35°C while stirring. Continue stirring for 10 minutes to obtain a uniform and transparent 1% (owf) dye solution.

[0047] S2. Place 100g of pure cotton knitted fabric (pre-wetted) into the dye cup and put it into the infrared sample dyeing machine. Raise the dye bath temperature to 50℃ at a heating rate of 2℃ / min and run at this temperature for 20 minutes.

[0048] S3. Add 10 g / L sodium carbonate solution to the dye bath to adjust the pH value of the dye bath to 11.0, and then raise the temperature to 65℃ and fix the color under this condition for 40 minutes.

[0049] S4. After the color fixation is complete, drain the dye liquor, rinse the fabric sample with cold water, then soap it at 95℃ (2g / L soap flakes) for 15 minutes, and finally wash it with warm and cold water and dry it.

[0050] The high color fastness reactive dye prepared in this embodiment is suitable for dyeing pure cotton fabrics.

[0051] Example 2

[0052] A reactive dye with high color fastness, based on the total weight of the reactive dye, is composed of the following components:

[0053] 88.0 wt% of reactive dye body, wherein the reactive dye body is CI Reactive Blue 19 (an anthraquinone dye containing vinyl sulfone sulfate reactive groups).

[0054] 12.0 wt% of a composite dispersion stabilizer;

[0055] The composite dispersion stabilizer is composed of the following components:

[0056] 7.0 wt% comb-type polycarboxylate dispersant, specifically sodium polycarboxylate water-reducing agent, with a solid content of 50%;

[0057] 1.0 wt% of an organic polyphosphonic acid chelating agent, specifically hydroxyethylidene diphosphonic acid (HEDP);

[0058] 4.0 wt% of fatty alcohol polyoxyethylene ether wetting agent, specifically JFC penetrant.

[0059] A method for preparing reactive dyes with high color fastness includes the following steps:

[0060] A. Weigh 1000 grams of the synthesized and filtered CI Reactive Blue 19 dye wet cake (dry content is 88%, i.e., contains 880 grams of dry dye body) and place it in a kneader.

[0061] B. Add 140g of sodium polycarboxylate superplasticizer with a solid content of 50% (70g dry weight), 10g of HEDP, and 40g of JFC penetrant to the kneader in sequence.

[0062] C. Mix at 45℃ with medium speed for 45 minutes until the material is homogeneous. After vacuum filtration, the resulting paste is sent to a pressure spray drying tower for drying, with the inlet air temperature controlled at 190℃ and the outlet air temperature at 90℃, to obtain a blue powdery high-fastness reactive dye product.

[0063] A process for dyeing cellulose fiber materials using reactive dyes with high color fastness includes the following steps:

[0064] S1. Weigh 20 grams of the reactive dye prepared in this example and slowly add it to a dye cup containing 980 ml of hard water (hardness of 250 ppm CaCO3) at 30°C while stirring. Continue stirring for 15 minutes to obtain a homogeneous 2% (owf) dye solution.

[0065] S2. Place 100g of viscose fiber woven fabric (pre-wetted) into the dye cup and put it into the infrared sample dyeing machine. Raise the dye bath temperature to 55℃ at a heating rate of 1.5℃ / min and keep it at that temperature for 15 minutes.

[0066] S3. Add 15 g / L of a mixed alkaline solution of sodium carbonate and sodium bicarbonate (mass ratio 3:1) to the dye bath to adjust the pH of the dye bath to 10.8, then raise the temperature to 68℃ and fix the color for 50 minutes.

[0067] S4. After color fixing, drain the waste liquid and perform cold water washing, 95℃ soap washing (2g / L soap flakes, 10 minutes), hot water washing and cold water washing in sequence, and finally dry at 80℃.

[0068] The high color fastness reactive dye prepared in this embodiment is suitable for dyeing regenerated cellulose fibers such as viscose fibers.

[0069] Example 3

[0070] A reactive dye with high color fastness, based on the total weight of the reactive dye, is composed of the following components:

[0071] 92.5 wt% of reactive dye body, wherein the reactive dye body is CI Reactive Black 5 (an azo dye containing two reactive groups).

[0072] 7.5wt% composite dispersion stabilizer;

[0073] The composite dispersion stabilizer is composed of the following components:

[0074] 4.0 wt% comb-type polycarboxylate dispersant, specifically sodium salt of maleic acid-acrylic acid copolymer, with a solid content of 40%;

[0075] 2.0 wt% of organic polyphosphonic acid chelating agent, specifically diethylenetriaminepentamethylenephosphonic acid (DTPMP);

[0076] 1.5 wt% of fatty alcohol polyoxyethylene ether wetting agent, specifically JFC penetrant.

[0077] A method for preparing reactive dyes with high color fastness includes the following steps:

[0078] A. Weigh 1000 grams of the synthesized and filtered CI Reactive Black 5 dye wet cake (dry content of 92.5%, i.e., containing 925 grams of dry dye body) and place it in a mixing container.

[0079] B. Add 100g of sodium maleic acid-acrylic acid copolymer with a solid content of 40% (40g dry weight), 20g of DTPMP, and 15g of JFC penetrant to the mixing tank in sequence.

[0080] C. Start stirring and heat the mixture to 55°C, stirring continuously for 1.5 hours to ensure uniform mixing. Transfer the resulting slurry to a centrifugal spray dryer, controlling the inlet air temperature at 175°C and the outlet air temperature at 80°C to obtain a black powdery high-fastness reactive dye product.

[0081] A process for dyeing cellulose fiber materials using reactive dyes with high color fastness includes the following steps:

[0082] S1. Weigh 40 grams of the reactive dye prepared in this example and slowly add it to a dye cup containing 960 ml of hard water (hardness of 250 ppm CaCO3) at 40°C under high-speed stirring. Continue stirring for 8 minutes to obtain a homogeneous 4% (owf) dye solution.

[0083] S2. Place 100g of linen-cotton blended fabric (55 / 45, pre-wetted) into the dye cup and place it in an infrared sample dyeing machine. Heat to 60℃ at a rate of 2.5℃ / min and run at this temperature for 25 minutes.

[0084] S3. Add 12 g / L sodium carbonate solution to the dye bath to adjust the pH value of the dye bath to 11.2, and then raise the temperature to 70℃ and fix the color for 30 minutes.

[0085] S4. After color fixing, drain the dye solution and proceed with the following steps: rinse thoroughly with cold water, soap at 95℃ (3g / L soap flakes, 20 minutes), wash with hot water and then rinse with cold water. Finally, dry the product.

[0086] The high color fastness reactive dye prepared in this embodiment is suitable for dark-colored dyeing of blended fabrics such as linen and cotton.

[0087] Comparative Example 1

[0088] A reactive dye, based on the total weight of the reactive dye, comprises the following components:

[0089] 100.0 wt% of reactive dye body, wherein the reactive dye body is CI Reactive Red 195.

[0090] No complex dispersion stabilizers are added.

[0091] A method for preparing the reactive dye, the steps of which are consistent with those in Example 1.

[0092] A process for dyeing cellulose fiber materials using this reactive dye, the steps of which are the same as in Example 1.

[0093] This comparative example is used to verify the basic performance of reactive dyes in hard water environments without the addition of any composite dispersing stabilizers.

[0094] Comparative Example 2

[0095] A reactive dye, based on the total weight of the reactive dye, comprises the following components:

[0096] The reactive dye body comprises 95.0 wt%, wherein the reactive dye body is CI Reactive Red 195.

[0097] 5.0 wt% comb-type polycarboxylate dispersant, specifically sodium salt of maleic acid-acrylic acid copolymer, with a solid content of 40%.

[0098] No organic polyphosphonic acid chelating agents or fatty alcohol polyoxyethylene ether wetting agents are added.

[0099] A method for preparing the reactive dye, the steps of which are consistent with those in Example 1.

[0100] A process for dyeing cellulose fiber materials using this reactive dye, the steps of which are the same as in Example 1.

[0101] This comparative example is used to verify the chemical stability and dyeing effect of the dye when only comb-type polycarboxylate dispersants are used, without the synergistic effect of chelating agents and wetting agents.

[0102] Comparative Example 3

[0103] A reactive dye, based on the total weight of the reactive dye, comprises the following components:

[0104] The reactive dye body comprises 90.0 wt%, wherein the reactive dye body is CI Reactive Red 195.

[0105] 10.0 wt% of a conventional adjuvant combination; the conventional adjuvant combination consists of the following components:

[0106] 5.0 wt% sodium lignosulfonate (a traditional dispersant);

[0107] 1.5 wt% of tetrasodium ethylenediaminetetraacetate (EDTA·4Na, a traditional chelating agent);

[0108] 3.5 wt% JFC penetrant.

[0109] A method for preparing the reactive dye, the steps of which are consistent with those in Example 1.

[0110] A process for dyeing cellulose fiber materials using this reactive dye, the steps of which are the same as in Example 1.

[0111] This comparative example is used to verify the difference in performance and effect between the present invention and the present invention when a conventionally used combination of additives is used to replace the novel composite dispersant and stabilizer of the present invention.

[0112] Comparative Example 4

[0113] A reactive dye, based on the total weight of the reactive dye, comprises the following components:

[0114] The reactive dye body comprises 92.0 wt%, wherein the reactive dye body is CI Reactive Red 195.

[0115] 8.0 wt% conventional additives; said conventional additives consist of the following components:

[0116] 4.0 wt% sodium lignosulfonate was used as a dispersant;

[0117] 4.0 wt% anhydrous sodium sulfate was used as a filler salt.

[0118] A process for dyeing cellulose fiber materials using this reactive dye, the steps of which are the same as in Example 1.

[0119] The components and proportions in this comparative example are designed with reference to the formulations of similar mature products on the market, serving as a benchmark for market reference.

[0120] The reactive dyes obtained in the examples and comparative examples were subjected to the following performance tests.

[0121] Note: All performance tests below were conducted under conditions where the water hardness was no higher than 250 ppm (calculated as calcium carbonate).

[0122] I. Chemical Stability Test

[0123] This test quantifies the dye’s anti-flocculation ability during dissolution and storage.

[0124] 1) Flocculation rate

[0125] Quantitative indicator: Flocculation rate (%) = (1 - dye concentration in supernatant after settling / initial dye concentration) × 100%

[0126] This indicator reflects the tendency of dyes to aggregate and precipitate in the liquid phase. The lower the value, the better the dye stability, thus reducing the occurrence of color spot defects in the fabric.

[0127] Reference standards: You can refer to the relevant principles of dye dispersibility testing in the "Compilation of Dye Standards", or draw on the basic ideas of solution preparation and static observation in GB / T5549-2010 "Determination of Surface Tension of Surfactants by Pull-up Liquid Film Method", but the core measurement method is the concentration method.

[0128] Test method: Weigh 1.000 g of the sample dye, dissolve it in water with a hardness of 250 ppm (calculated as CaCO3), transfer it to a 100 mL volumetric flask, and dilute to volume to prepare a 10 g / L stock solution. After thorough mixing, immediately transfer 50 mL to a 50 mL stoppered colorimetric tube. Place the colorimetric tube in a constant temperature water bath and let it stand at (25±1) ℃. After standing for 30 minutes, 60 minutes, and 24 hours, carefully pipette a certain volume (e.g., 2 mL) of the supernatant from 2 cm below the liquid surface (avoid disturbing the precipitate). If precipitation is severe, centrifuge at 4000 r / min for 10 minutes before pipetting the supernatant. After appropriately diluting the supernatant, use a UV-Vis spectrophotometer to measure its absorbance at the maximum absorption wavelength (λmax) of the dye, and compare it with the absorbance of the initial solution. Calculate the concentration using the Lambert-Beer law.

[0129] 2) Solution particle size distribution

[0130] Quantitative indicators: D50 (median particle size, nm), D90 (particle size at 90% cumulative distribution, nm), polydispersity index (PDI)

[0131] D50 represents the average particle size, D90 reflects the tail characteristics of large particles, and PDI characterizes the uniformity of particle size distribution. The smaller the D50 and D90 values ​​and the closer the PDI is to 0, the more uniform and stable the dispersion system is, and the less likely it is to form large particles that cause color spots.

[0132] Reference standard: ISO 13320:2020 Particle size analysis – Laser diffraction method

[0133] Test Method: Weigh 1.000 g of the sample dye, dissolve it in water with a hardness of 250 ppm (calculated as CaCO3), transfer it to a 100 mL volumetric flask, and dilute to volume to prepare a 10 g / L stock solution. Before testing, the stock solution concentration needs to be diluted to 0.1 g / L with hard water. Using a laser particle size analyzer, start the instrument and use water as the dispersion medium for background measurement. Stir the diluted dye solution at low speed on a magnetic stirrer to ensure homogeneity, and then add it dropwise to the instrument's circulation cell. After the signal stabilizes, begin the measurement. Each sample should be measured at least 3 times and the average value should be taken.

[0134] 3) Solution absorbance

[0135] Quantitative indicator: Absorbance attenuation rate (%) = (Absorbance at time T / Initial absorbance) × 100%

[0136] This indicator reflects the concentration loss of dye molecules due to hydrolysis (breakage of covalent bonds) or aggregation (intermolecular interactions). The lower the decay rate, the higher the chemical and physical stability of the dye in solution.

[0137] Reference standard: General Chapter 0401 of the Pharmacopoeia of the People's Republic of China, Ultraviolet-Visible Spectrophotometry.

[0138] Test method: Weigh 1.000 g of the sample dye, dissolve it in water with a hardness of 250 ppm (calculated as CaCO3), transfer it to a 100 mL volumetric flask, and make up to volume to prepare a 10 g / L stock solution. During testing, dilute it with hard water to an absorbance value between 0.3 and 0.8 (usually at λmax). Use a UV-Vis spectrophotometer, with hard water as a reference, to calibrate the baseline. Inject the diluted test solution into a 1 cm quartz cuvette and immediately measure its initial absorbance (A0) at λmax. Then transfer the solution in the cuvette to a sealed vial and store it at (25±1) °C in the dark. Measure the absorbance again (A0) after 2 hours, 4 hours, 8 hours, and 24 hours. t Calculate the absorbance decay rate at each time point.

[0139] II. Staining Effect Test

[0140] This part of the test demonstrates that improved dye stability can help improve the actual dyeing quality.

[0141] 1) Color spot / stain assessment

[0142] Quantitative indicators: Rating from 1 to 5. Level 5: Uniform fabric surface, no color spots or stains; Level 4: Slight color spots / stains; Level 3: Obvious color spots / stains; Level 2: Severe color spots / stains; Level 1: Extremely severe color spots / stains. This indicator is used to determine whether the fabric made from the dye has any defects.

[0143] Reference standard: GB / T22849-2014 "Knitted Fabrics"

[0144] Test Method: Standard bleached cotton fabric (such as mercerized cotton) conforming to GB / T411-2008 "Cotton Printed and Dyed Fabrics" is selected and cut to a specified size (e.g., 10cm × 20cm). The dyeing process is carried out in an infrared small-sample dyeing machine. The dyeing liquor ratio is fixed at 1:20, and the dye dosage is 1% (owf). The dyeing process is performed according to the above procedures. After dyeing, the fabric sample is soaped, washed, and dried according to standard procedures. Then, the dyed fabric sample is conditioned under standard atmospheric conditions (temperature 20±2℃, relative humidity 65±4%) for at least 4 hours. The fabric sample is placed in a standard light source box using a D65 standard light source. Multiple inspectors independently observe and rate the fabric surface with their eyes at a 45° angle and a distance of 60-80cm. The final rating is the average of the multiple inspectors' ratings or a consensus grade.

[0145] 2) Dyeing uniformity

[0146] Quantitative indicator: ΔE (color difference) value. The ΔE value comprehensively reflects the total difference of color along the lightness (L), red-green axis (a), and yellow-blue axis (b*). The smaller the ΔE value, the more uniform the dyeing, proving that the dye is stably distributed in the dye bath and the dyeing process is uniform. Usually, when ΔE < 1.0, the difference is difficult for the human eye to perceive.

[0147] Reference standard: GB / T8424.3-2001 "Textiles - Tests for Color Fastness - Calculation of Color Difference"

[0148] Test Method: Same as the "Color Spot / Stain Evaluation" test, complete the preparation of dyed fabric samples. Use a computer colorimeter with a D65 light source and 10° standard observer conditions. After instrument preheating and calibration, measure in three different areas (left, center, and right) of each dyed fabric sample (or add more points as needed). Measure each area at least three times and take the average value to obtain the L, a, b* values ​​for that point. Using the color value of the center point of the fabric sample as the standard value (Ls, as, b*s), calculate the color difference ΔE between each of the other points and the standard point.

[0149] Calculation formula: ΔE=[(L*-Ls) 2 +(a-as) 2 +(bb*s) 2 ]^1 / 2

[0150] The final report includes the maximum color difference (ΔEmax) and the average color difference (ΔEavg).

[0151] III. Colorfastness Performance Test

[0152] This part of the test is to demonstrate that the final product has improved colorfastness.

[0153] 1) Wash fastness

[0154] Quantitative indicators: original sample color change (grade) and lining fabric staining (grade), rated from 1 to 5. The higher the grade, the better the wash fastness.

[0155] Reference standard: GB / T3921-2008 "Textiles - Tests for color fastness - Color fastness to washing"

[0156] Test Method: A dyed fabric sample prepared according to standard methods, measuring 4cm × 10cm, is used. One piece of multifiber lining fabric (compliant with GB / T7568.7) or two pieces of single-fiber lining fabric (one cotton, the other the most abundant fiber in the fabric, such as polyester), of the same size, are taken and sewn together along the short side to form a composite sample. The composite sample is placed in the stainless steel container of a wash fastness tester, and 150mL of test solution containing 5g / L standard soap flakes (liquor ratio 1:50) and 25 stainless steel balls are added. The sample is treated at (40±2)℃ for 30 minutes. After removal, it is rinsed twice with distilled water and then dried at room temperature. A gray sample card is used under a standard light source, and trained graders grade the color change of the original sample and the staining of the lining fabric.

[0157] 2) Color fastness to rubbing

[0158] Quantitative indicators: dry rubbing (grade) and wet rubbing (grade). The wet rubbing grade is the most challenging aspect for dark-colored fabrics, directly reflecting the amount of surface dye. Dry rubbing primarily reflects the strength of the dye's bond with the fiber. Moisture causes the fiber to swell and dissolves and migrates unfixed dye. Wet rubbing is extremely sensitive to the amount of surface dye on the fabric. A high wet rubbing grade directly proves that the dye fixation rate of this invention is high and the surface dye removal is thorough.

[0159] Reference standard: GB / T3920-2008 "Textiles - Tests for color fastness - Color fastness to rubbing"

[0160] Test method: Cut the dyed fabric sample into a size of not less than 20cm × 5cm and fix it on the sample stage of the color fastness to rubbing tester. Wrap a standard dry cotton rubbing cloth around the rubbing head of the tester and rub the sample back and forth along a 100mm track 10 times, each reciprocation lasting about 1 second, with a downward pressure of 9N. After wetting another rubbing cloth, perform the same operation. After rubbing, dry the rubbing cloth at room temperature and use a gray scale to rate the degree of staining of the two rubbing cloths.

[0161] 3) Lightfastness

[0162] Quantitative indicators: Blue wool sample grade, rated from 1 to 8. A higher grade indicates better lightfastness, meaning a stronger ability of the dye's molecular structure to withstand UV damage. This is crucial for products such as automotive interiors, outdoor clothing, and home curtains. Dyes with high lightfastness ensure that dyed products are less prone to fading over long-term use.

[0163] Reference standard: GB / T8427-2008 "Textiles - Tests for color fastness - Color fastness to artificial light: Xenon arc"

[0164] Test Method: The dyed fabric sample was partially covered along with a set of blue wool standards (grades 1-8) to create a test card. The test card was placed in a xenon arc lamp lightfastness tester and continuously exposed to sunlight under specified conditions. During the exposure, the changes in the blue wool standards were observed periodically. The first stage endpoint was reached when the color change of the grade 4 standard reached the grade 4 of the gray test card. The second stage endpoint was reached when the color change of the grade 6 standard reached the same level. The test card was then removed, and the difference between the exposed and unexposed parts of the sample was immediately compared under a standard light source with the degree of change of the blue wool standards to determine its lightfastness grade.

[0165] Table 1: Results of Chemical Stability Tests

[0166] flocculation rate D50 D90 Multi-dispersion index Absorbance attenuation rate Example 1 1.5 185 395 0.21 2.1 Example 2 2.2 210 450 0.23 2.8 Example 3 3.0 235 510 0.25 3.5 Comparative Example 1 28.5 1250 2850 0.65 12.5 Comparative Example 2 15.0 650 1650 0.48 8.0 Comparative Example 3 8.5 450 1100 0.35 1.9 Comparative Example 4 20.0 880 1900 0.52 9.5

[0167] The flocculation rates of Examples 1 to 3 ranged from 1.5% to 3.0%, significantly lower than all comparative examples. In contrast, Comparative Example 2, lacking the organic polyphosphonic acid chelating agent, saw its flocculation rate rise to 15.0%, confirming that this component plays a crucial role in maintaining system stability by integrating calcium and magnesium ions. Compared to Comparative Example 3, representing conventional technology, the flocculation rate of the present invention was reduced by approximately 7%. This indicates a substantial decrease in the flocculation rate of the dye prepared by the present invention. A lower flocculation rate means a lower likelihood of color spots and stains appearing on the surface of fabrics dyed with the dye prepared by the present invention, resulting in improved product quality.

[0168] The median particle size D50 of Examples 1 to 3 is lower than that of the comparative example. Similarly, the D90 and polydispersity index are also lower than those of the comparative example. This indicates that the present invention can effectively suppress the formation of large particle aggregates and the dye can be dispersed more uniformly under hard water conditions. The D90 and polydispersity index of Comparative Example 2 are significantly higher, proving that a single dispersant cannot maintain stability in hard water and must work synergistically with a chelating agent to achieve the best effect.

[0169] Regarding the change in absorbance of the solution, the differences among all samples were small. Comparative Example 3 (i.e., the traditional formulation) was slightly better than the present invention. This is consistent with the known characteristics of traditional chelating agents such as EDTA in inhibiting the chemical degradation of dyes, which objectively shows that the advantages of the present invention are mainly focused on improving physical dispersion stability.

[0170] Comprehensive analysis shows that the composite dispersant stabilizer used in this invention significantly improves the solubility and storage stability of reactive dyes in hard water environments through the synergistic effect between its components, thereby solving the problem of dye flocculation caused by fluctuations in water quality and operation.

[0171] Table 2: Results of Staining Effect Test

[0172] Color spot / stain assessment (grade) ΔE Example 1 5 0.6 Example 2 4-5 0.8 Example 3 4 1.0 Comparative Example 1 2 3.5 Comparative Example 2 3 2.2 Comparative Example 3 4 1.8 Comparative Example 4 3-4 2.5

[0173] The data shows that the color spot / stain ratings of Examples 1 to 3 reached level 4 or above, while the ratings of Comparative Examples 1, 2, and 4 were only level 3 or lower. A high color spot rating means that the fabric surface is clean, reducing the possibility of defective fabric caused by dye flocculation. This directly improves the first-grade product rate and reduces production losses.

[0174] Regarding dyeing uniformity, the color difference (ΔE) values ​​of the examples ranged from 0.6 to 1.0, significantly lower than those of the comparative examples. A small color difference value indicates consistent color across the left, center, and right sides of the fabric, demonstrating uniform dyeing and effectively preventing product quality degradation due to uneven coloring. In Comparative Example 2, the color difference reached 2.2 after the absence of the chelating agent, indicating that metal ions in hard water severely affected the uniform distribution of dye on the fibers.

[0175] Compared to Comparative Example 3, which represents conventional technology, this invention has advantages in both color spot control and dyeing uniformity. Although Comparative Example 3 has a acceptable color spot rating, its color difference is significantly greater than that of this invention, indicating that conventional formulations may not be able to fully guarantee dyeing uniformity.

[0176] Comprehensive analysis shows that the present invention fundamentally improves the application performance of dyes through the synergistic effect of composite dispersing stabilizers, thereby translating into a practical improvement in dyeing quality and effectively solving the problems of color spots and uneven color caused by dye flocculation.

[0177] Table 3: Results of Colorfastness Performance Tests

[0178] Original color change level Staining grade of lining Dry friction grade Wet friction level Blue wool standard grade Example 1 4-5 4-5 4-5 4-5 6 Example 2 4-5 4 4-5 4 6 Example 3 4 4 4 4 5-6 Comparative Example 1 3 2-3 3 2 5 Comparative Example 2 4 3 4 2-3 5-6 Comparative Example 3 4 3-4 4 3 6 Comparative Example 4 4 3 4 2-3 5

[0179] The data above shows that the color fastness to washing and wet rubbing of Examples 1 to 3 all reached level 4 or above, while the two indicators of Comparative Examples 1, 2 and 4 were generally level 3 or below. High levels of color fastness to washing and wet rubbing mean that the dyed fabric is less likely to contaminate other clothes during washing and is less likely to fade during daily friction (especially in wet conditions), which directly improves the durability and quality of the product.

[0180] Regarding wash fastness, there was little difference among all samples, indicating that the strength of the bond between the dye and the fiber mainly depends on the dye itself, with auxiliaries having a relatively small impact. It is noteworthy that Comparative Example 2 had a wet rubbing fastness of only 2-3, which again proves that the lack of chelating agents leads to increased color floating, and these poorly bonded dyes are the main reason for the decrease in wet rubbing fastness.

[0181] Compared with Comparative Example 3, which represents conventional technology, the wet rubbing fastness and staining fastness of the present invention are significantly improved. Although the light fastness of Comparative Example 3 is comparable to that of the present invention, this is an inherent characteristic of dye molecules, while the present invention has a greater advantage in solving the key fastness problem related to floating color.

[0182] Comprehensive analysis shows that the present invention improves the stability of dye chemicals and reduces the occurrence of dye floating, making it easier to remove in subsequent washing. This improvement improves the wet rubbing fastness and soaping staining fastness of the dye, solving the problem of poor color fastness of dark-colored varieties.

[0183] The above description is merely an example and illustration of the concept of the present invention. Any modifications or additions to the specific embodiments described, or substitutions made by those skilled in the art, shall fall within the scope of protection claimed by the present invention.

Claims

1. A reactive dye with high color fastness, characterized in that, Based on the total weight of the reactive dye, it consists of the following components: The reactive dye body comprises 85.0 wt% to 95.5 wt%, wherein the reactive dye body is an azo dye containing vinyl sulfone sulfate reactive groups; 4.5wt%-15.0wt% of a composite dispersion stabilizer; The composite dispersion stabilizer is composed of the following components: 3.0wt%-8.0wt% comb-type polycarboxylate dispersant; 0.5wt%-2.0wt% of organic polyphosphonic acid chelating agents; 1.0wt%-3.0wt% of fatty alcohol polyoxyethylene ether wetting agents; The comb-shaped polycarboxylate dispersant is sodium salt of maleic acid-acrylic acid copolymer; The organic polyphosphonic acid chelating agent is at least one of diethylenetriamine pentamethylphosphonic acid or hydroxyethylidene diphosphonic acid; The fatty alcohol polyoxyethylene ether wetting agent is a JFC penetrant.

2. A method for preparing the high color fastness reactive dye according to claim 1, characterized in that, Includes the following steps: A: Mix the reactive dye bulk with comb-type polycarboxylate dispersant, organic polyphosphonic acid chelating agent and fatty alcohol polyoxyethylene ether wetting agent evenly; B: Stir at a temperature of 40℃ to 60℃ for 0.5 hours to 2 hours; C: Spray drying is performed to obtain a reactive dye composition powder with high color fastness.

3. A process for dyeing cellulose fiber materials using the high color fastness reactive dye as described in claim 1, characterized in that, Includes the following steps: S1: Dissolve the reactive dye composition in water with a hardness of not more than 250 ppm at a dissolution temperature of 25°C to 45°C to obtain a dye solution; S2: Immerse the cellulose fiber material in the dye solution for dyeing. The dyeing temperature is 40°C to 60°C, and the dyeing time is 10 minutes to 30 minutes. S3: Add alkali to fix the color. The fixing temperature is 60℃ to 70℃, the fixing pH value is 10.5 to 11.5, and the fixing time is 30 minutes to 60 minutes. S4: Perform water washing, soap washing and post-treatment.

4. The application of the high color fastness reactive dye as described in claim 1 in the dyeing of cellulose fiber materials.