Disperse dye direct-jet ink with high light fastness, preparation method thereof and ink jet printing method

Abstract

The invention provides disperse dye direct-jet ink with high light fastness, a preparation method of the disperse dye direct-jet ink and an ink jet printing method. The direct-injection ink comprises a water-soluble metal ion complex and disperse color paste, wherein the color paste contains disperse dye. The water-soluble metal ion complex is generated by reaction of metal ions and a coordination agent and can be decomposed during heating, and the highest decomposition temperature is not more than 160 DEG C, so that specific functional groups contained in the disperse dye and the metal ions are subjected to complexation reaction, and the disperse dye has the characteristic of uniform dispersion. The structural stability of the chromophoric group in the disperse dye is remarkably improved, so that the dye can effectively resist the damage of energy transferred by photons in sunlight to the molecular structure of the dye, thereby realizing high light fastness. In addition, the ink also has the advantages of simple process, low cost, good environmental protection property and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of inkjet printing, and particularly relates to a high-solar fastness direct jet printing ink of disperse dye, a preparation method thereof and an inkjet printing method. BACKGROUND

[0002] Direct jet printing ink of disperse dye is a technology widely used in textile direct inkjet printing. It has attracted widespread attention due to its simple operation, rich color, and suitability for small batch production. However, despite the significant progress in the application of disperse dyes in ink, it still faces some key challenges in practical application, especially the problem of light fastness of dyes. During the use of textiles, especially outdoor applications, sunlight has wave-particle duality. The sunlight that transfers energy in the form of photons has a strong impact on the molecular structure of the dye. When the basic structure of the chromophore part in the dye structure is destroyed by photons, the color of the light emitted by the dye chromophore will change, usually becoming lighter until it is colorless.

[0003] Therefore, how to improve the light fastness of disperse dyes has always been the focus of research in the field of textile dyeing. At present, the methods to improve the light fastness of dyes mainly include the following: 1. Modification of dye molecular structure: By introducing light-resistant groups (such as aromatic groups, conjugated structures, etc.) into the dye molecule, the light stability of the dye molecule is improved. However, this method usually requires complex synthesis process, and may have adverse effects on the color and color fastness of the dye.

[0004] 2. Use of light stabilizers: Add light stabilizers (such as ultraviolet absorbers, quenchers, etc.) to the ink to absorb or scatter ultraviolet light, reducing the excitation of light energy on the dye molecule. However, the addition of light stabilizers may increase the cost of the ink, and its effect is often limited by environmental conditions (such as humidity, temperature).

[0005] 3. Post-treatment process: Through heat treatment, chemical cross-linking and other post-treatment processes, the binding force between the dye and the fiber is enhanced, thereby indirectly improving the light fastness. However, these methods usually require additional process steps, increasing production costs and complexity.

[0006] 4. Optimization of dye and fiber combination: By improving the steps or adding additives, the binding force between the dye molecule and the fiber is enhanced, reducing the migration or shedding of the dye molecule under external conditions. However, this method cannot directly solve the problem of instability of the dye molecule itself.

[0007] Although the above-mentioned methods improve the light fastness of disperse dyes to some extent, there are still problems: the structural stability of the dye molecules themselves is not fundamentally improved, and the dye molecules are still prone to chemical degradation under the action of light energy; the existing methods usually require additional process steps or additives, increasing the production cost and complexity; the effect of the existing methods is often limited by environmental conditions, and it is difficult to maintain stable light fastness in complex environments.

[0008] Therefore, developing an ink that can fundamentally improve the structural stability of dye molecules so that it can have high solar fastness is still a problem to be solved in the field of textile dyeing. SUMMARY

[0009] The first object of the present application is to provide a high-solar-fastness disperse dye direct inkjet ink to solve the problem of low solar fastness of current disperse dye inkjet ink.

[0010] The second object of the present application is to provide a preparation method of a high-solar-fastness disperse dye direct inkjet ink, which is used to prepare the above-mentioned high-solar-fastness disperse dye direct inkjet ink.

[0011] The third object of the present application is to provide an inkjet printing method, which applies the above-mentioned high-solar-fastness disperse dye direct inkjet ink.

[0012] To achieve the first object of the present application, the present application provides a high-solar-fastness disperse dye direct inkjet ink, which comprises a water-soluble metal ion complex and a color paste containing disperse dyes, the water-soluble metal ion complex is generated by the reaction of metal ions and complexing agents, and the water-soluble metal ion complex will decompose when heated, and the decomposition temperature is not higher than 160℃; the disperse dye contains functional groups that can undergo complexation reaction with metal ions. The metal ions and the complexing agent form a stable complex at room temperature, and the coordination bond of the complex is unstable and easy to be destroyed at high temperature, and decomposes. At room temperature, the water-soluble metal complex is stable and does not decompose, and only decomposes when heated. The heating temperature is higher than 60℃, preferably the heating temperature is higher than 70℃, and the water-soluble metal complex will decompose. When the ink is printed on the substrate, the water-soluble metal complex decomposes after high-temperature treatment, the coordination bond formed by the metal ions and the complexing agent is destroyed, the metal ions are released and undergo complexation reaction with specific functional groups in the dye molecules to form a new stable complex, reducing the damage of external energy (such as photons) to the dye molecules, significantly improving the structural stability of the chromophore group in the disperse dye, making it can effectively resist the damage of the energy of photon transmission in sunlight to the structure of the dye molecule, thereby realizing high solar fastness. In addition, the ink also has the advantages of simple process, low cost and good environmental protection.

[0013] Further, the metal ion is selected from at least one of Fe3+, Al3+, Cr3+, Cu2+, Zn2+; the complexing agent is selected from EDTA (ethylenediaminetetraacetic acid); and the disperse dye contains at least one functional group selected from hydroxyl, amino, carboxyl, carbonyl, and cyano.

[0014] The metal ion has strong coordination ability and can form a more stable complex, and the complexing agent is common and easy to obtain, and can form a stable complex with various metal ions; the disperse dye contains a functional group with strong coordination ability, which is more easily complexed with the metal ion to form a stable complex, thereby ensuring the light fastness of the printed ink.

[0015] Further, the direct inkjet ink further comprises a humectant, and the humectant comprises urea, and the pH of the ink at room temperature is less than 7.5.

[0016] The water-soluble metal complex is stable under acidic and neutral conditions, but the coordination bond is easily broken under alkaline conditions, so the pH of the ink is controlled to be less than 7.5, and the reaction between the metal ion and the disperse dye does not occur during the preparation and storage of the ink, thereby ensuring the stability of the ink.

[0017] The pH of the ink at room temperature is preferably 6.5-7.5, and more preferably 7. Under acidic conditions, urea will form a salt, which will destroy the stability of the ink. Under alkaline conditions, the metal complex is destroyed, and the metal ion will complex with the dye, which will destroy the stability. Therefore, when the pH is in the range of 6.5-7.5, the ink can maintain good stability, and when the pH is 7, the ink has the best stability.

[0018] Further, the humectant further comprises a polyol, such as glycerol, ethylene glycol, propylene glycol, triethylene glycol, 1,4-butanediol, etc.

[0019] The polyol has good moisturizing effect, and the addition of urea allows the urea in the ink to react with water to release ammonia gas when the ink is subjected to high temperature treatment, so that the pH of the ink is weakly alkaline (pH 8-9), and the coordination bond between the metal ion and the ligand is destroyed. Under the conditions of weak alkalinity and high temperature, the internal metal ion is released. These metal ions coordinate with specific functional groups in the disperse dye molecules. Since the ink is weakly alkaline (pH 8-9) during this process, the metal ion will not be complexed with EDTA again, thereby ensuring the coordination reaction between the metal ion and the disperse dye, and further ensuring the formation of a stable complex.

[0020] Further, the direct inkjet ink further comprises a pH buffer, and the pH buffer is selected from a phosphate buffer solution.

[0021] The phosphate buffer can precisely regulate the ink to a stable pH range as a pH buffer, has a large buffering capacity, and can effectively resist external pH fluctuations to ensure the stability of the ink.

[0022] In a further aspect, the colorant includes a disperse dye and a dispersant, and the dispersant is selected from polyacrylic acid, styrene maleic anhydride copolymer.

[0023] In a further aspect, the direct jet ink further includes a surfactant, and the surfactant is selected from at least one of silicone surfactant, siloxane-based surfactant, and polyether-modified silicone surfactant.

[0024] In a further aspect, the direct jet ink includes, by mass percentage, 10% to 30% of the colorant, 1% to 8% of the water-soluble metal ion complex, 0.5% to 2% of the surfactant, 20% to 40% of the humectant, 1% to 5% of the pH buffer, 0.1% to 0.5% of the bactericide, and the balance of deionized water.

[0025] The ink including the components and contents described above has good stability and good printing fluency.

[0026] To achieve the second object of the present application, the present application provides a preparation method of a direct jet ink of disperse dye with high solar fastness, including the following steps: S1: mixing a colorant with a surfactant, a humectant, a bactericide, and deionized water, and stirring uniformly to obtain a mixed solution; S2: adding a pH buffer to the mixed solution obtained in step S1, and adjusting the pH range to below 7.5; S3: adding a water-soluble metal ion complex to the mixed solution obtained in step S2, stirring uniformly, and filtering to obtain a direct jet ink of disperse dye with high solar fastness.

[0027] The preparation method of the ink described above has simple process, low cost, and good environmental protection.

[0028] To achieve the third object of the present application, the present application provides a printing method, which is implemented by using the direct jet ink of disperse dye with high solar fastness described in any one of the above aspects. The printing method specifically includes the following steps: S1: printing the direct jet ink of disperse dye with high solar fastness on a substrate; S2: performing high-temperature treatment on the substrate, the temperature of the high-temperature treatment being 160°C to 200°C, and the treatment time being 3 min to 10 min; and S3: cooling the substrate to obtain a printed substrate with high solar fastness.

[0029] The metal ions in the ink are complexed with the disperse dye by high-temperature treatment, thereby improving the solar fastness of the ink, and the process is simple and has low cost. DETAILED DESCRIPTION

[0030] The application provides a high-solar fastness dispersed dye direct inkjet ink, the direct inkjet ink comprises 10-30% of color paste, 1-8% of water-soluble metal ion complex, 0.5-2% of surfactant, 20-40% of humectant, 1-5% of pH buffer, 0.1-0.5% of bactericide and the balance of deionized water in percentage by mass. The pH value of the ink at normal temperature is less than 7.5. The pH value of the ink at normal temperature is preferably 6.5-7.5, and more preferably 7.

[0031] The water-soluble metal ion complex is generated by the reaction of metal ions and a complexing agent, and the water-soluble metal ion complex is decomposed when heated, and the decomposition temperature is not higher than 160 DEG C. At normal temperature, the water-soluble metal complex is stable and does not decompose, and only decomposes when heated. The heating temperature is higher than 60 DEG C, and preferably, the water-soluble metal complex decomposes when the heating temperature is higher than 70 DEG C.

[0032] The metal ion is selected from at least one of Fe 3+, Al 3+, Cr 3+, Cu 2+, Zn 2+ The metal ion salt for providing the metal ion can be selected from, but is not limited to, FeCl3, Fe(NO3)3, AlCl3, Cr(NO3)3, CuSO4, CuCl2, Cu(NO3)2, ZnCl2 and Zn(NO3)2.

[0033] The complexing agent is selected from EDTA (ethylenediaminetetraacetic acid).

[0034] The color paste contains dispersed dyes and dispersants, and the dispersed dyes contain functional groups that can react with metal ions, and the specific functional groups can be at least one of hydroxyl, amino, carboxyl, carbonyl and cyano. The dispersed dyes can be selected from, but are not limited to, at least one of Disperse Blue 359, Disperse Blue 291, Disperse Blue 7, Disperse Blue 35, Disperse Blue 85, Disperse Red 277, Disperse Red 278, Disperse Red 19, Disperse Red E-4B, Disperse Red 167, Disperse Red 153, Disperse Yellow 184, Disperse Yellow 114, Disperse Yellow 56, Disperse Yellow 54, Disperse Yellow 60, Disperse Yellow 39, Disperse Orange 5, Disperse Orange 76, Disperse Orange 30 and Disperse Orange 29. The dispersants are selected from at least one of polyacrylic acid and styrene maleic anhydride copolymer, and can be selected from, but are not limited to, at least one of DISPERBYK-190, DISPERBYK-2018, DISPERBYK-2019 of BYK Company, Dispex Ultra PA 4550, Dispex Ultra PA 4560, Efka PA 4401, JONCRYL HPD 96, JONCRYL HPD 296 and BYK-1590 of BASF.

[0035] The surfactant is selected from at least one of organic silicon surfactant, siloxane-based surfactant, polyether-modified silicon-based surfactant, and can be specifically selected from, but is not limited to, Evonik Surfynol 465, TEGOWET260 of Degussa, TEGO WET27, BYK-342 of BYK, BYK-333, BYK-33 of BYK, BYK-387, and Dynol series of Air Chemical.

[0036] The humectant includes urea, and in addition to the urea, the humectant can further include at least one of polyhydric alcohols, which can be selected from, but is not limited to, at least one of glycerol, ethylene glycol, propylene glycol, triethylene glycol, and 1,4-butanediol.

[0037] The pH buffer is selected from a phosphate buffer pair solution, and is specifically a phosphate buffer pair solution prepared by mixing sodium dihydrogen phosphate (NaH2PO4) and disodium hydrogen phosphate (Na2HPO4) at a molar ratio of 1:1.

[0038] The bactericide is selected from BIT (1,2-benzisothiazol-3-ketone).

[0039] The application provides a preparation method of a high-solar fastness direct-disperse dye inkjet ink, and the preparation method comprises the following steps: S1: mixing a color paste with a surfactant, a humectant, a bactericide and deionized water, and stirring uniformly to obtain a mixed solution; S2: adding a pH buffer to the mixed solution obtained in step S1, and adjusting the pH range to below 7.5; S3: adding a water-soluble metal ion complex to the mixed solution obtained in step S2, stirring uniformly, and filtering to obtain the high-solar fastness direct-disperse dye inkjet ink.

[0040] The application adopts a preparation method of a water-soluble metal ion complex, and the preparation method specifically comprises the following steps: P1: preparing a complexing agent solution, an indicator solution and a metal ion solution; P2: adjusting the pH of the indicator solution to 2-4, and then adding the metal ion solution; P3: adding the complexing agent solution drop by drop into the above solution for titration until the color change of the indicator reaches a preset condition, and thus the water-soluble metal ion complex is obtained.

[0041] The application provides an inkjet printing method, which is realized by using the above high-solar fastness direct-disperse dye inkjet ink, and the printing method specifically comprises the following steps: (1) printing the high-solar fastness direct-disperse dye inkjet ink on a substrate, and the substrate is a fabric; (2) The substrate is put into an oven for high temperature treatment, the temperature of the high temperature treatment is 160-200℃, and the treatment time is 3-10 minutes; (3) After the substrate is cooled, the printed substrate with high solar fastness is obtained.

[0042] The application is further described below in combination with specific examples.

[0043] Preparation of water-soluble metal iron ion complex (Fe-EDTA): (1) Prepare 0.01 mol / L Fe3+ solution, 0.01 mol / L EDTA solution and 0.01 mol / L sulfosalicylic acid solution; (2) Adjust the pH of the sulfosalicylic acid solution to 2-4, and add Fe 3+ solution; (3) Add EDTA solution drop by drop to the solution in (2) for titration until the solution color changes from purple red to light yellow, and the water-soluble metal iron ion complex is obtained.

[0044] Preparation of water-soluble metal copper ion complex (Cu-EDTA): (1) Prepare 0.01 mol / L Cu 2⁺ solution, 0.01 mol / L EDTA solution and 0.01 mol / L dimethyl phenol orange solution; (2) Adjust the pH of the dimethyl phenol orange solution to 2-4, and add Cu 2⁺ solution; (3) Add EDTA solution drop by drop to the solution in (2) for titration until the solution color changes from purple red to yellow green, and the water-soluble metal copper ion complex is obtained.

[0045] Preparation of color paste: Mix 15-30% of the disperse dye with 20-35% of the dispersing agent and the balance of water by mass percentage, and grind for 3-5 hours to obtain the color paste. In the following examples and comparative examples, the color paste is obtained by mixing 20% of the disperse dye with 30% of the dispersing agent and the balance of water, and grinding for 5 hours, wherein the dispersing agent is DISPERBYK-190.

[0046] The disperse dye direct inkjet ink of the examples is prepared by the above preparation method according to the composition and content in Tables 1-4, and the disperse dye direct inkjet ink of the comparative examples is prepared by the above preparation method according to the composition and content in Table 5.

[0047] Table 1

[0048] Table 2

[0049] Table 3

[0050] Table 4

[0051] Table 5

[0052] The ink of the above examples and comparative examples was subjected to a sunlight fastness test, and the specific test method was as follows: (1) The ink of the above examples and comparative examples was printed on a polyester fiber fabric, respectively, and was subjected to high temperature treatment at 180℃ for 5min. (2) The above fabric was placed in a standard sunlight box, and the standard light fastness test method (ISO 105-B02:2014) was used to detect the sunlight fastness level.

[0053] The test results are shown in Table 6 below.

[0054] Table 6

[0055] As can be seen from the above table, the comparative example without adding the water-soluble metal ion complex of the present application has poor sunlight fastness. The metal ion and the complexing agent in the dispersion ink of the present application form a stable complex at room temperature, and no reaction occurs between the metal ion and the disperse dye during the preparation and storage of the ink, ensuring the stability of the ink. When the ink is printed on the substrate, the water-soluble metal complex is decomposed after high temperature treatment, the coordination bond formed by the metal ion and the complexing agent is broken, the metal ion is released and forms a complex with the specific functional group in the dye molecule, forming a stable complex, reducing the damage of external energy (such as photons) to the dye molecule, significantly improving the structural stability of the chromophore group in the disperse dye, so that it can effectively resist the damage of the energy of photon transmission in sunlight to the structure of the dye molecule, thereby realizing high sunlight fastness. In addition, the ink has the advantages of simple process, low cost, good environmental protection, etc.

[0056] Finally, it should be emphasized that the above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various changes and modifications, and any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A disperse dye direct-injection ink with high lightfastness, characterized in that: The direct-injection ink includes a water-soluble metal ion complex and a color paste. The color paste contains a disperse dye. The water-soluble metal ion complex is generated by the reaction of metal ions with a coordinating agent. The water-soluble metal ion complex decomposes when heated, and the decomposition temperature does not exceed 160°C. The disperse dye contains functional groups that can undergo complexation reactions with the metal ions.

2. The high lightfastness disperse dye direct-injection ink as described in claim 1, characterized in that: The metal ion is selected from at least one of Fe³⁺, Al³⁺, Cr³⁺, Cu²⁺, and Zn²⁺; The ligand is selected from EDTA; The disperse dye contains at least one functional group selected from hydroxyl, amino, carboxyl, carbonyl, and cyano groups.

3. The high lightfastness disperse dye direct-to-garment ink as described in claim 1, characterized in that: The direct-injection ink also includes a humectant, which includes urea, and the ink has a pH value of less than 7.

5.

4. The high lightfastness disperse dye direct-to-garment ink as described in claim 3, characterized in that: The moisturizer also includes polyols.

5. The high lightfastness disperse dye direct-to-garment ink as described in claim 1, characterized in that: The direct-injection ink also includes a pH buffer, which is selected from phosphate buffer solutions.

6. The high lightfastness disperse dye direct-to-ink as described in any one of claims 1 to 5, characterized in that: The color paste includes the disperse dye and the dispersant, wherein the dispersant is selected from at least one of polyacrylic acid and styrene-maleic anhydride copolymer.

7. The high lightfastness disperse dye direct-to-ink as described in any one of claims 1 to 5, characterized in that: The direct-injection ink also includes a surfactant, which is selected from at least one of organosilicon surfactants, siloxane surfactants, and polyether-modified silicone surfactants.

8. The high lightfastness disperse dye direct-to-ink as described in any one of claims 1 to 5, characterized in that: By weight percentage, the direct-to-garment ink comprises 10% to 30% color paste, 1% to 8% water-soluble metal ion complex, 0.5% to 2% surfactant, 20% to 40% humectant, 1% to 5% pH buffer, 0.1% to 0.5% bactericide, and the balance being deionized water.

9. The method for preparing a disperse dye direct-injection ink with high lightfastness as described in claim 8, characterized in that, Includes the following steps: S1: Mix the color paste with the surfactant, the humectant, the bactericide and deionized water, and stir until uniform to obtain a mixture; S2: Add the pH buffer to the mixture obtained in step S1 to adjust the pH range to below 7.5; S3: Add the water-soluble metal ion complex to the mixture obtained in step S2, stir evenly, and then filter to obtain a disperse dye direct-injection ink with high lightfastness.

10. An inkjet printing method, characterized in that: The printing method is implemented using a high lightfastness disperse dye direct-injection ink as described in any one of claims 1 to 8, and the printing method specifically includes the following steps: S1: High lightfastness disperse dye direct-injection ink is printed onto the substrate; S2: The substrate is subjected to high-temperature treatment, wherein the temperature of the high-temperature treatment is 160℃~200℃ and the treatment time is 3min~10min; S3: After the substrate cools down, a printing substrate with high lightfastness is obtained.

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