High-fixation coloring agent and application thereof

Abstract

The invention relates to the technical field of coloring agents, in particular to a high-color-fixation type coloring agent and application thereof. The invention relates to a high color fixation type coloring agent, which comprises the following substances by weight: 1-10 parts of a modified reactive black 5KNB dye; 3-8 parts of a color fixation accelerant; the modified reactive black 5KNB dye comprises a reactive black 5KNB dye grafted with a sulfonyl chloride group, the reactive black 5KNB dye is modified through the sulfonyl chloride group, and due to the fact that the sulfonyl chloride group has high electrophilicity, the sulfonyl chloride group can be subjected to nucleophilic substitution reaction with terminal amino groups of nylon fibers to generate stable sulfonamide bonds. Compared with the unmodified active black 5KNB, the sulfonyl chloride group directly targets the nylon amino group, and the color fixation obstacle of the traditional active dye on nylon is broken through.

Description

Technical Field

[0001] This invention relates to the technical field of dyes, and in particular to a high-fixation dye and its application. Background Technology

[0002] Reactive Black 5KNB, a diazo reactive dye, has long been primarily used for dyeing cellulosic fibers (such as cotton and linen). Its molecular structure contains sulfonic acid groups and vinyl sulfone reactive groups, which can form covalent bonds with cellulose hydroxyl groups under alkaline conditions, achieving high fixation and good wet fastness. However, when applied to nylon fibers, this dye exhibits significant limitations. Nylon fibers are mainly composed of polyamide macromolecules with low terminal amino content. The sulfonic acid groups in Reactive Black 5KNB ionize into anions in water, causing electrostatic repulsion with the isoelectric point (pH 5-6) of nylon fibers, resulting in low adsorption rates. Simultaneously, due to the lack of numerous hydroxyl groups in nylon, the dye-dependent vinyl sulfone nucleophilic substitution reaction is difficult to carry out, with a fixation rate of only 40-50% under conventional processes, and requiring high temperature and strong acid conditions to promote the reactivity of the protonated amino groups.

[0003] To improve the applicability of reactive black 5KNB to nylon fibers, existing technologies mainly increase the reaction sites between the dye and nylon through grafting reactions. Although such methods can improve the fixation rate, the synthesis process is complex, and the introduced reactive groups are easily hydrolyzed and deactivated during the dyeing process, resulting in poor reproducibility.

[0004] Regarding the aforementioned related technologies, the inventors discovered that in the current technical solutions for improving the applicability of Reactive Black 5KNB to nylon fibers, the increased molecular weight of the dye modified with multiple active groups leads to a reduced diffusion rate within the fiber, which easily causes uneven dyeing. Furthermore, the water solubility of the modified dye decreases, requiring the addition of high doses of co-solvents, thus increasing the COD load of wastewater. Summary of the Invention

[0005] In order to improve the poor dyeing performance of Reactive Black 5KNB on nylon fiber materials, this application provides a high-fixation dyeing agent and its application.

[0006] In a first aspect, this application provides a high-fixation dyeing agent, which adopts the following technical solution:

[0007] A high-fixation dyeing agent, comprising the following substances in parts by weight:

[0008] 1-10 parts of modified reactive black 5KNB dye;

[0009] 3-8 parts of color-fixing accelerator;

[0010] The modified reactive black 5KNB dye includes a reactive black 5KNB dye grafted with sulfonyl chloride groups.

[0011] Through the above technical solution, this application modifies reactive black 5KNB dye with sulfonyl chloride groups. Because sulfonyl chloride groups have high electrophilicity, they can undergo nucleophilic substitution reactions with the terminal amino groups of nylon fibers to generate stable sulfonamide bonds. Compared to unmodified reactive black 5KNB, the sulfonyl chloride groups directly target the nylon amino groups, overcoming the traditional limitations of reactive dyes in fixing nylon.

[0012] Furthermore, the modified reactive black 5KNB dye is prepared using the following technical solution:

[0013] Take reactive black 5KNB dye and place it in dichloromethane. Stir and mix, and add phosphorus pentachloride dropwise at low temperature. Stir and react, and then heat to room temperature. Keep warm and stir for 4 hours. Filter and take filter cake, wash and dry, and collect modified reactive black 5KNB dye.

[0014] Through the above technical solution, this application uses the phosphorus pentachloride sulfonyl chlorination reaction to prepare modified dyes. Since the sulfonic acid group of reactive black 5KNB is converted into a highly reactive sulfonyl chloride group under the action of PCl5, this application optimizes the reaction temperature and suppresses the side reactions of hydrolysis or self-polymerization of sulfonyl chloride through a low temperature environment. The use of non-aqueous solvents can effectively avoid the problem of water molecules causing PCl5 to fail. This process realizes the transformation of sulfonic acid group into highly reactive group in one step, providing key reaction sites for subsequent color fixation.

[0015] Furthermore, the modified reactive black 5KNB dye is also grafted with dual reactive groups, and the modified reactive black 5KNB dye is prepared using the following technical solution:

[0016] The modified reactive black 5KNB dye was dissolved in DMF, and N-methyldiaminopropane and triethylamine were added. After reacting under a nitrogen atmosphere, the dye was precipitated in an ice-water bath, washed, and dried to obtain the modified reactive black 5KNB dye with a tertiary amine bridged structure.

[0017] Through the above technical solution, this application further introduces a tertiary amine bridging structure based on sulfonyl chloride modification. The sulfonyl chloride intermediate undergoes an amination reaction with N-methyldiaminopropane, using the tertiary amine group as the cationic precursor. The propane chain spacer arm alleviates steric hindrance and increases the probability of contact with the fiber. In this application, triethylamine is used as an acid-binding agent to neutralize the HCl generated in the reaction, preventing the sulfonamide bond from breaking. Simultaneously, a nitrogen atmosphere effectively avoids the oxidation and degradation of the tertiary amine. This modification scheme constructs a bifunctional dye framework that combines covalent bond anchoring and electrostatic adsorption.

[0018] Furthermore, the modified reactive black 5KNB dye with the tertiary amine bridging structure is also grafted with cationic active groups. The modified reactive black 5KNB dye with the tertiary amine bridging structure grafted with cationic active groups is prepared using the following technical solution:

[0019] The modified reactive black 5KNB dye with a tertiary amine-bridged structure was dissolved in acetonitrile, diethyl sulfate was added, and the mixture was heated and refluxed. The solvent was removed under reduced pressure, and the mixture was recrystallized with acetone to obtain the modified reactive black 5KNB dye with a tertiary amine-bridged structure grafted with cationic active groups.

[0020] Through the above technical solution, this application converts tertiary amines into permanent quaternary ammonium salt cations. After alkylation of the tertiary amine with diethyl sulfate, and its use as a dye, the positive charge of the quaternary ammonium salt on the dye strongly binds to the protonated amino groups of nylon, reserving reaction sites for subsequent in-situ generation of vinyl sulfone groups. Simultaneously, this application modifies the dye to possess both charge-driven adsorption and covalent bond permanent fixation dual-mode functions.

[0021] Furthermore, the color-fixing accelerator includes an acrylic acid-maleic anhydride copolymer with a molecular weight of 1800-2500 Da.

[0022] Through the above technical solution, this application uses an acrylic acid-maleic anhydride copolymer to form multiple hydrogen bonds with nylon amide groups, establishing a dense adsorption layer on the fiber surface to directionally attract positively charged quaternary ammonium salt modified dyes. Simultaneously, optimizing the molecular weight effectively ensures that the molecular chains are long enough to form a continuous adsorption layer, while also avoiding the problem of molecular chain entanglement hindering dye penetration into the fiber. This component solves the color spot problem caused by uneven dye distribution through a "spatial confinement effect."

[0023] Furthermore, the color-fixing accelerator also includes lanthanide metal citrate nanoclusters with a particle size of 50 nm.

[0024] Furthermore, the mass ratio of the lanthanum citrate nanoclusters to the acrylic acid-maleic anhydride copolymer is 1:(3-5).

[0025] Through the above technical solution, this application introduces lanthanide metal citrate nanoclusters and compoundes them in a mass ratio of 1:(3-5). The empty orbitals of lanthanum ions accept lone pair electrons from the oxygen atoms of nylon amide groups, thereby enhancing the nucleophilicity of the nitrogen atoms of the amide groups. At the same time, lanthanum ions coordinate with the sulfur atoms of sulfonyl chloride, bringing the spatial distance of the reactive groups closer, thereby further improving its color-fixing effect.

[0026] Furthermore, the lanthanide metal citrate nanoclusters include at least one of lanthanum citrate nanoclusters or cerium citrate nanoclusters.

[0027] Through the above technical solution, this application selects lanthanum citrate nanoclusters and cerium citrate nanoclusters as lanthanide metal citrate nanoclusters. The lanthanum ions form multidentate coordination bonds with high coordination numbers, which enhances the bonding stability with fibers. Cerium ions can effectively scavenge free radicals and protect dye chromophores from oxidative degradation.

[0028] Secondly, this application provides a dyeing method using a high-fixation dye, employing the following technical solution:

[0029] A staining method using a high-fixation dye includes the following steps:

[0030] Immerse nylon fibers in an aqueous solution of a color-fixing accelerator and treat at 40-50℃ for 10-20 minutes;

[0031] After adding modified reactive black 5KNB dye, adjust the pH and place the dyeing treatment at 70-75℃ for 30-50 minutes;

[0032] After staining is complete, raise the temperature to 80-90℃ and keep it warm for 15-30 minutes to fix the color;

[0033] The dyeing step can be completed by washing the nylon fibers with a neutral soap after the color fixation is completed.

[0034] Furthermore, the pH of the staining treatment is 4.5-5.5.

[0035] Through the above technical solution, this application achieves a breakthrough effect based on the high-fixation dyeing agent raw material system through a three-dimensional synergistic effect of temperature, pH, and time: In the neutral region of 70–75℃, the dye rapidly and uniformly dyes the fiber through electrostatic adsorption, and the copolymer pre-adsorption layer inhibits the ineffective migration of the dye; when the temperature is raised to the fixing region of 80–90℃, the nanoclusters catalyze and activate the nucleophilic substitution reaction of sulfonyl chloride, thereby doubling the covalent bonding efficiency of dye-fiber. This ultimately forms a dual fixing mechanism of "electrostatic adsorption directional anchoring + catalytic covalent permanent fixation," which significantly reduces energy consumption while completely solving the industry pain points of insufficient color fixation and fastness defects in nylon fiber dyeing.

[0036] In summary, this application has the following beneficial effects:

[0037] First, this application modifies the reactive black 5KNB dye with sulfonyl chloride groups. Because sulfonyl chloride groups have high electrophilicity, they can undergo nucleophilic substitution reactions with the terminal amino groups of nylon fibers to generate stable sulfonamide bonds. Compared to unmodified reactive black 5KNB, the sulfonyl chloride groups directly target the nylon amino groups, overcoming the traditional limitations of reactive dyes in fixing nylon.

[0038] Secondly, based on the modification with sulfonyl chloride, this application further introduces a tertiary amine bridging structure. The sulfonyl chloride intermediate undergoes an amination reaction with N-methyldiaminopropane, using the tertiary amine group as the cationic precursor. The propane chain spacer arm alleviates steric hindrance and increases the probability of contact with the fiber. In this application, triethylamine is used as an acid-binding agent to neutralize the HCl generated during the reaction, preventing the sulfonamide bond from breaking. Simultaneously, a nitrogen atmosphere effectively prevents the tertiary amine from oxidizing and failing. This modification scheme constructs a bifunctional dye framework that combines covalent anchoring and electrostatic adsorption.

[0039] Third, this application converts the tertiary amine into a permanent quaternary ammonium salt cation. After alkylation of the tertiary amine with diethyl sulfate, and using it as a dye, the positive charge of the quaternary ammonium salt on the dye strongly binds to the protonated amino groups of nylon, reserving reaction sites for the subsequent in-situ generation of vinyl sulfone groups. Simultaneously, this modification enables the dye to possess both charge-driven adsorption and covalent bond permanent fixation dual-mode functions.

[0040] Fourth, this application, based on the high-fixation dyeing agent raw material system, achieves a breakthrough effect through the three-dimensional synergy of temperature, pH, and time: In the neutral region of 70–75℃, the dye rapidly and uniformly dyes the fiber through electrostatic adsorption, and the copolymer pre-adsorption layer inhibits the ineffective migration of the dye; when the temperature is raised to the fixing region of 80–90℃, the nanoclusters catalyze and activate the nucleophilic substitution reaction of sulfonyl chloride, thus doubling the covalent bonding efficiency of dye-fiber. This ultimately forms a dual fixing mechanism of "electrostatic adsorption directional anchoring + catalytic covalent permanent fixation," significantly reducing energy consumption while completely solving the industry pain points of insufficient color fixation and fastness defects in nylon fiber dyeing. Detailed Implementation

[0041] The present application will be further described in detail below with reference to the embodiments.

[0042] Preparation Example 1

[0043] Dye 1

[0044] 100g of reactive black 5KNB (CAS17095-24-8) and 500mL of anhydrous dichloromethane were added to a dry reaction vessel. Under nitrogen protection, the temperature was lowered to 0-5℃, and then 120g of phosphorus pentachloride was slowly added dropwise, with the dropping rate controlled to ≤1mL / min. After the dropping was completed, the temperature was raised to 25℃ and stirred for 4h. The byproduct POCl3 was removed by suction filtration. The filter cake was washed three times with anhydrous ethanol at -20℃ and dried under vacuum at 50℃ to obtain the modified reactive black 5KNB dye.

[0045] Preparation Example 2

[0046] Dye 2

[0047] 100g of reactive black 5KNB (CAS17095-24-8) and 500mL of anhydrous dichloromethane were added to a dry reaction vessel. Under nitrogen protection, the temperature was lowered to 0-5℃, and then 120g of phosphorus pentachloride was slowly added dropwise, controlling the dropping rate to ≤1mL / min. After the addition was complete, the temperature was raised to 25℃ and stirred for 4h. The byproduct POCl3 was removed by suction filtration. The filter cake was washed three times with anhydrous ethanol at -20℃ and dried under vacuum at 50℃ to obtain modified reactive black 5KNB dye. 80g of modified reactive black 5KNB dye was dissolved in 400mL of anhydrous DMF, and 45g of N-methyldiaminopropane and 60g of triethylamine were added. The reaction was carried out at 40℃ for 6h under nitrogen protection. The reaction solution was poured into ice water at 0℃ to precipitate the precipitate. After filtration, the precipitate was washed with a water / ethanol mixture of equal mass ratio and dried at 60℃ to obtain modified reactive black 5KNB dye with a tertiary amine bridged structure.

[0048] Preparation Example 3

[0049] Dye 3

[0050] 100g of reactive black 5KNB (CAS17095-24-8) and 500mL of anhydrous dichloromethane were added to a dry reaction vessel. Under nitrogen protection, the temperature was lowered to 0-5℃, and then 120g of phosphorus pentachloride was slowly added dropwise, controlling the dropping rate to ≤1mL / min. After the addition was complete, the temperature was raised to 25℃ and stirred for 4h. The byproduct POCl3 was removed by suction filtration. The filter cake was washed three times with anhydrous ethanol at -20℃ and dried under vacuum at 50℃ to obtain modified reactive black 5KNB dye. 80g of modified reactive black 5KNB dye was dissolved in 400mL of anhydrous DMF, and 45g of N-methyldiaminopropane and 60g of triethylamine were added. The reaction was carried out at 40℃ for 6h under nitrogen protection. The reaction solution was poured into ice water at 0℃ to precipitate the precipitate. After filtration, the precipitate was washed with a water / ethanol mixture of equal mass ratio and dried at 60℃ to obtain modified reactive black 5KNB dye with a tertiary amine bridged structure.

[0051] 70g of modified reactive black 5KNB dye with a tertiary amine bridged structure was dissolved in 350mL of acetonitrile. After adding 55g of diethyl sulfate, the mixture was refluxed at 80℃ for 12h. The solvent was removed by vacuum distillation, and the residue was recrystallized three times with acetone to obtain the modified reactive black 5KNB dye with a tertiary amine bridged structure grafted with cationic active groups.

[0052] Preparation Example 4

[0053] Equal volumes of 0.1M sodium citrate and 0.1M lanthanum nitrate were mixed and reacted at 120℃ for 6 hours using a hydrothermal method. Lanthanum citrate nanoclusters were obtained by centrifugation.

[0054] Example 1

[0055] A high-fixation dyeing agent comprising 1 kg of dye 1 and 3 kg of acrylic acid-maleic anhydride copolymer with a molecular weight of 1800 Da.

[0056] A staining method using a high-fixation dye includes the following steps:

[0057] Nylon fibers were immersed in an aqueous solution of 3.5% (by mass) color-fixing accelerator at a mass ratio of 1:10 and treated at 40°C for 10 minutes.

[0058] After adding dye 1, adjust the pH to 4.5 and then place it at 70℃ for 30 minutes for staining treatment;

[0059] After staining is complete, raise the temperature to 80℃ and keep it at that temperature for 15 minutes to fix the color.

[0060] The dyeing step can be completed by washing the nylon fibers with a neutral soap after the color fixation is completed.

[0061] Example 2

[0062] A high-fixation dyeing agent comprising 5 kg of dye 1 and 5 kg of acrylic acid-maleic anhydride copolymer with a molecular weight of 2000 Da.

[0063] A staining method using a high-fixation dye includes the following steps:

[0064] Nylon fibers were immersed in an aqueous solution of 3.5% (by mass) color-fixing accelerator at a mass ratio of 1:10 and treated at 45°C for 15 minutes.

[0065] After adding dye 1, adjust the pH to 5.0 and then place it at 72℃ for 40 min for staining treatment;

[0066] After staining is completed, raise the temperature to 85℃ and keep it at that temperature for 22 minutes to fix the color;

[0067] The dyeing step can be completed by washing the nylon fibers with a neutral soap after the color fixation is completed.

[0068] Example 3

[0069] A high-fixation dyeing agent comprising 10 kg of dye 1 and 8 kg of acrylic acid-maleic anhydride copolymer with a molecular weight of 2500 Da.

[0070] A staining method using a high-fixation dye includes the following steps:

[0071] Nylon fibers were immersed in an aqueous solution of 3.5% (by mass) color-fixing accelerator at a mass ratio of 1:10 and treated at 50°C for 20 minutes.

[0072] After adding dye 1, adjust the pH to 5.5 and then place it at 75℃ for dyeing treatment for 50 min;

[0073] After staining is complete, raise the temperature to 90℃ and keep it at that temperature for 30 minutes to fix the color.

[0074] The dyeing step can be completed by washing the nylon fibers with a neutral soap after the color fixation is completed.

[0075] Example 4

[0076] A high-fixation dyeing agent comprising 5 kg of dye 2 and 5 kg of acrylic acid-maleic anhydride copolymer with a molecular weight of 2000 Da.

[0077] A staining method using a high-fixation dye includes the following steps:

[0078] Nylon fibers were immersed in an aqueous solution of 3.5% (by mass) color-fixing accelerator at a mass ratio of 1:10 and treated at 45°C for 15 minutes.

[0079] After adding dye 1, adjust the pH to 5.0 and then place it at 72℃ for 40 min for staining treatment;

[0080] After staining is completed, raise the temperature to 85℃ and keep it at that temperature for 22 minutes to fix the color;

[0081] The dyeing step can be completed by washing the nylon fibers with a neutral soap after the color fixation is completed.

[0082] Example 5

[0083] A high-fixation dyeing agent comprising 5 kg of dye 1 and 5 kg of acrylic acid-maleic anhydride copolymer with a molecular weight of 2000 Da.

[0084] A staining method using a high-fixation dye includes the following steps:

[0085] Nylon fibers were immersed in an aqueous solution of 3.5% (by mass) color-fixing accelerator at a mass ratio of 1:10 and treated at 45°C for 15 minutes.

[0086] After adding dye 3, adjust the pH to 5.0 and then place it at 72℃ for 40 min for staining treatment;

[0087] After staining is completed, raise the temperature to 85℃ and keep it at that temperature for 22 minutes to fix the color;

[0088] The dyeing step can be completed by washing the nylon fibers with a neutral soap after the color fixation is completed.

[0089] Example 6

[0090] A high-fixation dyeing agent comprises 5 kg of dye 1, 0.83 kg of lanthanum citrate nanoclusters, and 4.17 kg of acrylic acid-maleic anhydride copolymer with a molecular weight of 2000 Da.

[0091] A staining method using a high-fixation dye includes the following steps:

[0092] Nylon fibers were immersed in an aqueous solution of 3.5% (by mass) color-fixing accelerator at a mass ratio of 1:10 and treated at 45°C for 15 minutes.

[0093] After adding dye 3, adjust the pH to 5.0 and then place it at 72℃ for 40 min for staining treatment;

[0094] After staining is completed, raise the temperature to 85℃ and keep it at that temperature for 22 minutes to fix the color;

[0095] The dyeing step can be completed by washing the nylon fibers with a neutral soap after the color fixation is completed.

[0096] Example 7

[0097] A high-fixation dyeing agent comprises 5 kg of dye 1, 1.6 kg of lanthanum citrate nanoclusters, and 3.4 kg of acrylic acid-maleic anhydride copolymer with a molecular weight of 2000 Da.

[0098] A staining method using a high-fixation dye includes the following steps:

[0099] Nylon fibers were immersed in an aqueous solution of 3.5% (by mass) color-fixing accelerator at a mass ratio of 1:10 and treated at 45°C for 15 minutes.

[0100] After adding dye 3, adjust the pH to 5.0 and then place it at 72℃ for 40 min for staining treatment;

[0101] After staining is completed, raise the temperature to 85℃ and keep it at that temperature for 22 minutes to fix the color;

[0102] The dyeing step can be completed by washing the nylon fibers with a neutral soap after the color fixation is completed.

[0103] Example 8

[0104] A high-fixation dyeing agent comprises 5 kg of dye 1, 0.8 kg of lanthanum citrate nanoclusters, 0.8 kg of cerium citrate nanoclusters, and 3.4 kg of acrylic acid-maleic anhydride copolymer with a molecular weight of 2000 Da.

[0105] A staining method using a high-fixation dye includes the following steps:

[0106] Nylon fibers were immersed in an aqueous solution of 3.5% (by mass) color-fixing accelerator at a mass ratio of 1:10 and treated at 45°C for 15 minutes.

[0107] After adding dye 3, adjust the pH to 5.0 and then place it at 72℃ for 40 min for staining treatment;

[0108] After staining is completed, raise the temperature to 85℃ and keep it at that temperature for 22 minutes to fix the color;

[0109] The dyeing step can be completed by washing the nylon fibers with a neutral soap after the color fixation is completed.

[0110] Comparative Example 1

[0111] Compared with Example 1, in Comparative Example 1, unmodified reactive black 5KNB was used instead of dye 1.

[0112] Comparative Example 2

[0113] Compared to Example 1, Comparative Example 1 did not include acrylic acid-maleic anhydride copolymer with a molecular weight of 1800 Da.

[0114] Performance testing

[0115] The dyes prepared in Examples 1-8 and Comparative Examples 1-2 were used for dyeing, and the dyed nylon fibers were tested according to the following standards:

[0116] Fixation rate: Tested according to standard GB / T 2391-2014 "Determination of Fixation Rate of Dyes";

[0117] Wet rubbing fastness: Tested according to standard GB / T 3920-2008 "Textiles - Tests for color fastness to rubbing"; the specific test results are shown in Table 1 below:

[0118] Table 1 Performance Test Table

[0119]

[0120]

[0121] Based on the test data from Examples 1-8 and Comparative Examples 1-2 above:

[0122] A comparison of Examples 1-3 and Comparative Examples 1-2 reveals that the technical solution of this application modifies the reactive black 5KNB dye with sulfonyl chloride groups, causing a nucleophilic substitution reaction with the terminal amino groups of nylon fibers to generate stable sulfonamide bonds. Compared to unmodified reactive black 5KNB, the sulfonyl chloride groups directly target the amino groups of nylon, overcoming the traditional limitations of reactive dyes in fixing nylon.

[0123] Furthermore, by comparing Example 1 and Comparative Example 2, it is further illustrated that the technical solution of this application utilizes an acrylic acid-maleic anhydride copolymer to form multiple hydrogen bonds with nylon amide groups, establishing a dense adsorption layer on the fiber surface to directionally attract positively charged quaternary ammonium salt modified dyes. Simultaneously, optimizing the molecular weight effectively ensures that the molecular chains are long enough to form a continuous adsorption layer, while also avoiding the problem of molecular chain entanglement hindering dye penetration into the fiber.

[0124] Comparing Example 4 and Example 2, it can be seen that the technical solution of this application, based on sulfonyl chloride modification, further introduces a tertiary amine bridging structure. The sulfonyl chloride intermediate undergoes an amination reaction with N-methyldiaminopropane, using a tertiary amine group as the cationic precursor. The propane chain spacer arm alleviates steric hindrance and increases the probability of contact with the fiber. In this application, triethylamine is used as an acid-binding agent to neutralize the HCl generated in the reaction, preventing the sulfonamide bond from breaking. Simultaneously, a nitrogen atmosphere effectively avoids the oxidation and degradation of the tertiary amine. This modification scheme constructs a bifunctional dye framework that combines covalent anchoring and electrostatic adsorption.

[0125] Comparing Example 5 and Example 2, it can be seen that this application converts the tertiary amine into a permanent quaternary ammonium salt cation. After the tertiary amine undergoes alkylation with diethyl sulfate and is used as a dye, the positive charge of the quaternary ammonium salt on the dye strongly binds to the protonated amino groups of nylon, reserving reaction sites for the subsequent in-situ generation of vinyl sulfone groups. At the same time, the modification in this application enables the dye to possess both charge-driven adsorption and covalent bond permanent fixation dual-mode functions.

[0126] Finally, referring to Examples 6-8, this application further illustrates that lanthanum citrate nanoclusters and cerium citrate nanoclusters are selected as lanthanide metal citrate nanoclusters. Lanthanum ions form multidentate coordination bonds with high coordination numbers, enhancing the bonding stability with fibers. Cerium ions effectively scavenge free radicals, protecting dye chromophores from oxidative degradation. This significantly increases the efficiency of dye-fiber covalent bonding. Ultimately, a dual fixation mechanism of "electrostatic adsorption directional anchoring + catalytic covalent permanent fixation" is formed, significantly reducing energy consumption while completely solving the problem of insufficient dyeing fixation rate of nylon fibers.

[0127] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

[0128] All publications, patent applications, patents, and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings commonly understood by those skilled in the art. In case of conflict, the definitions in this specification shall prevail.

[0129] When this specification uses the prefixes “known to those skilled in the art,” “prior art,” or similar terms to derive materials, substances, methods, steps, apparatus, or components, the objects derived from such prefixes cover those commonly used in the art at the time of this application, but also include those that are not currently commonly used but will become generally recognized in the art as suitable for similar purposes.

[0130] In the context of this specification, except where expressly stated otherwise, any matters or issues not mentioned shall apply directly to those known in the art without any modification.

Claims

1. A high fixation type dyeing agent, characterized by comprising: Comprise the following weight parts of the following substances: Modified reactive black 5KNB dye 1-10 parts; Fixing promoter 3-8 parts; The modified reactive black 5KNB dye comprises a reactive black 5KNB dye grafted with a sulfonyl chloride group.

2. The high substantive dyeing agent according to claim 1, characterized in that, The modified reactive black 5KNB dye is made by the following technical scheme: Take the reactive black 5KNB dye and place it in dichloromethane, stir and mix, and add phosphorus pentachloride dropwise in a low temperature environment, stir and react, and then warm up to room temperature, and then keep stirring for 4 hours, filter the filter cake, wash and dry, and collect the modified reactive black 5KNB dye.

3. The high substantive dyeing agent according to claim 1, characterized by, The modified reactive black 5KNB dye is also grafted with a double active group, and the modified reactive black 5KNB dye is made by the following technical scheme: Take the modified reactive black 5KNB dye and dissolve it in DMF, add N-methyl diamino propane and triethylamine, react under a nitrogen atmosphere, then precipitate in an ice water bath and wash and dry, to prepare the modified reactive black 5KNB dye with a tertiary amine bridging structure.

4. The high substantive dyeing agent according to claim 3, characterized in that, The modified reactive black 5KNB dye with a tertiary amine bridging structure is also grafted with a cationic active group, and the modified reactive black 5KNB dye with a tertiary amine bridging structure grafted with a cationic active group is made by the following technical scheme: Take the modified reactive black 5KNB dye with a tertiary amine bridging structure and dissolve it in acetonitrile, add diethyl sulfate and heat and reflux, remove the solvent under reduced pressure, and recrystallize from acetone, to prepare the modified reactive black 5KNB dye with a tertiary amine bridging structure grafted with a cationic active group.

5. The high substantive dyeing agent according to claim 1, characterized by, The fixing promoter comprises an acrylic acid-maleic anhydride copolymer with a molecular weight of 1800-2500 Da.

6. The high substantive dyeing agent according to claim 5, characterized in that, The fixing promoter also comprises lanthanide metal citrate nanoclusters with a particle size of 50 nm.

7. The high substantive dyeing agent according to claim 6, characterized in that, The mass ratio of the lanthanum citrate nanoclusters to the acrylic acid-maleic anhydride copolymer is 1:(3-5).

8. The high substantive dyeing agent according to claim 6, characterized by The lanthanide metal citrate nanoclusters comprise at least one of lanthanum citrate nanoclusters or cerium citrate nanoclusters.

9. A dyeing method using the high fixation type dyeing agent according to any one of claims 1 to 8, characterized by, Comprise the following steps: Take the nylon fiber and immerse it in an aqueous solution of the fixing promoter, and treat it at 40-50°C for 10-20 minutes; After adding the modified reactive black 5KNB dye, adjust the pH and dye at 70-75°C for 30-50 minutes; After the dyeing is complete, warm up to 80-90°C, and keep the temperature for 15-30 minutes for fixing; Wash the nylon fiber after fixing with a neutral soaping agent, to complete the dyeing step.

10. The dyeing method of a high solid dyeing agent according to claim 9, characterized by, The pH of the dyeing treatment is 4.5-5.5.

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