High-color-fastness disperse dye direct-injection ink and preparation method thereof, and process method of disperse dye ink direct-injection printing

Abstract

The invention provides high-color-fastness disperse dye direct-injection ink and a preparation method thereof, and a process method of disperse dye ink direct-injection printing, the high-color-fastness disperse dye direct-injection ink comprises disperse dye color paste, a self-crosslinking agent, a penetrant and a moisture absorbent; and the self-crosslinking agent is selected from resin with the self-crosslinking temperature of 45-60 DEG C. Under the combined action of the self-crosslinking agent, the penetrant and the moisture absorbent, the disperse dye direct-jet ink jet-printed on the fabric has high rubbing fastness, high washing fastness and excellent pattern definition and color expressive force, and meanwhile, the procedures of pretreatment sizing and post-treatment washing can be omitted; the process flow is simplified, the production cost is controlled, and the environmental pollution is greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of ink preparation, specifically to a high color fastness disperse dye direct-to-garment ink and its preparation method, and a process method for direct-to-garment printing of disperse dye ink. Background Technology

[0002] Disperse dye direct-to-garment printing technology is widely used in the textile printing industry due to its advantages such as no need for plate making, high-precision pattern printing, and rapid response. Its typical production process includes the following steps: first, the fabric is sized; then, disperse dye ink is directly sprayed onto the fabric surface using a digital inkjet printer; next, the fabric is dried and wound up; finally, it undergoes high-temperature color development and washing processes to set and rewind the finished product. In this process, washing is a crucial step in ensuring color fastness. Printed products that have not been washed have poor color fastness (rubbing fastness, washing fastness). This step washes away any ink that has not adhered to the fabric, achieving good color fastness. However, the washing process consumes a large amount of water, energy, and time, and generates a significant amount of wastewater. The cumbersome process and energy consumption constitute a large proportion of the cost of disperse dye direct-to-garment printing, becoming a key bottleneck restricting the economic benefits and large-scale promotion of this technology.

[0003] Disperse dyes that fail to bind effectively to the fibers without being washed will cause the problem of floating dye. Research has found that the occurrence of floating dye is mainly due to two factors: First, to control ink diffusion and ensure pattern sharpness, a paste needs to be applied to the fabric beforehand. This paste partially hinders the full penetration and binding of dye into the fibers during the subsequent high-temperature color development process, resulting in unfixed dye residue remaining on the fiber surface, forming loose dye. Furthermore, the paste may harden or alter the fabric's feel after high-temperature treatment, therefore it must be thoroughly removed by washing. Secondly, to achieve rich, vibrant colors and eliminate white gaps in the print, the actual ink volume often needs to exceed the fabric's normal absorption capacity by 1.5 to 2.0 times. After high-temperature color development, excess ink exceeding the fiber's binding capacity cannot be fixed, becoming the main source of floating ink, which must be removed by washing. Reducing the ink volume to decrease floating ink can easily lead to insufficient dyeing of the underlying fibers, resulting in "white gaps" and affecting the appearance quality. Adding a penetrant to the ink can promote dye penetration, but it also exacerbates the lateral diffusion (bleeding) of ink between fibers, damaging the fineness and clarity of the pattern.

[0004] In addition, during the drying and finishing stage, if conventional rolling methods are used, the squeezing and friction between fabric layers can easily lead to color staining, resulting in an increased defect rate.

[0005] Therefore, how to effectively reduce or completely eliminate the pretreatment sizing and posttreatment washing processes, while ensuring or even improving the color fastness, pattern clarity and color performance of the print, and achieving a streamlined process, control of production costs and a significant reduction in environmental pollution, has become a core challenge that needs to be overcome in the field of direct-to-garment printing of disperse dye inks and a goal that the industry continues to pursue. Summary of the Invention

[0006] The primary objective of this invention is to provide a high-colorfastness disperse dye direct-to-garment ink to address the problems of existing direct-to-garment ink printing processes being complex, having high production costs, and lacking sufficient colorfastness, pattern clarity, and color performance.

[0007] The second objective of this invention is to provide a process method for direct-to-garment printing of disperse dye inks, which is achieved by using the aforementioned high-color-fastness disperse dye ink.

[0008] A third objective of this invention is to provide a method for preparing a high-color-fastness disperse dye direct-injection ink, for use in preparing the aforementioned high-color-fastness disperse dye direct-injection ink.

[0009] To achieve the aforementioned first objective, the present invention provides a high color fastness disperse dye direct-injection ink, comprising disperse dye paste, and further comprising a self-crosslinking agent, a penetrant, and a hygroscopic agent; the self-crosslinking agent is selected from resins with a self-crosslinking temperature of 45°C to 60°C.

[0010] The disperse dye direct-injection ink provided in this invention includes a crosslinking agent, a penetrant, and a hygroscopic agent. The self-crosslinking agent has a moderate self-crosslinking temperature, facilitating crosslinking and film formation during the drying stage. This avoids the problem of low self-crosslinking temperatures causing self-crosslinking during the preparation stage, which could affect subsequent use. During the drying stage, the self-crosslinking agent undergoes a crosslinking reaction on the fiber surface, forming a dense crosslinked film. This self-formed crosslinked film creates a three-dimensional network structure, significantly improving the mechanical properties of the inkjet coating. This effectively fixes dye molecules, improves rubbing fastness, and prevents staining caused by fabric friction during the drying and winding stages. In the subsequent high-temperature color development stage, the self-crosslinking agent continues to stabilize dye molecules. Combined with the effects of the penetrant and hygroscopic agent, this reduces color floating and improves color fastness. Specifically, during the high-temperature color development stage, the hygroscopic agent absorbs water vapor, and then, through the action of the penetrant, quickly wets and penetrates into the fabric. The self-crosslinking agent stabilizes the dye molecules, ensuring uniform dyeing and complete dye-fabric bonding. This results in high color fastness after color development, preventing white showing and guaranteeing excellent pattern clarity and color performance. Because the combined action of the penetrant and hygroscopic agent ensures rapid wetting and penetration during the color development stage, additional penetration is no longer needed during the printing stage. Only the basic ink amount required for the printed pattern needs to be achieved, thus ensuring that the ink amount does not exceed the fabric's bonding limit and preventing ink floating. Furthermore, with the appropriate ink amount, the ink penetration is greatly controlled with the help of the film-forming effect of the self-crosslinking agent, reducing or eliminating the pretreatment sizing process while still achieving a clear pattern. In summary, under the combined action of the self-crosslinking agent, penetrant, and hygroscopic agent, the disperse dye direct-injection ink of this invention, when printed onto fabric, exhibits high rubbing fastness, high wash fastness, excellent pattern clarity, and superior color performance. Simultaneously, it eliminates the need for pretreatment sizing and post-treatment washing processes, simplifying the process flow, controlling production costs, and significantly reducing environmental pollution.

[0011] A further option is to use mannitol as the penetrant, which accounts for 1% to 2% of the disperse dye direct-to-garment ink by mass percentage.

[0012] At this dosage, during the high-temperature color development process, the dispersed dye molecules and water will quickly wet and penetrate into the fabric along with the penetrant, achieving uniform dyeing and complete bonding between the dye and the fabric. This also avoids the problem of excessive penetration leading to bleeding and negatively impacting the clarity of the pattern if too much penetrant is added; or insufficient penetration during ink color development, resulting in uneven dyeing, floating color after color development, decreased wash fastness and rubbing fastness, and the problem of white showing through.

[0013] A further option is to use urea as the hygroscopic agent, which accounts for 5% to 8% of the disperse dye direct-to-ink by mass percentage.

[0014] At this dosage, during the high-temperature color development process, the dried ink can fully absorb moisture, providing a combined penetration effect with the aforementioned penetrant. Adding too much hygroscopic agent at high temperatures can cause the ink's pH to rise excessively, negatively impacting color saturation; conversely, adding too little hygroscopic agent can prevent the ink from quickly absorbing sufficient moisture during color development, resulting in insufficient combined penetration with the penetrant, uneven coloring, floating color after color development, decreased wash fastness and rubbing fastness, and white showing-through issues.

[0015] A further option is to select a water-based self-crosslinking acrylic copolymer emulsion as the self-crosslinking agent, which accounts for 3% to 5% of the disperse dye direct-injection ink by mass percentage.

[0016] At this dosage, the ink exhibits good jetting stability and cross-linking properties. It avoids the problem of excessive self-cross-linking agent causing poor ink flow and jetting stability in continuous printing; or insufficient self-cross-linking agent causing inadequate cross-linking with the fabric during drying and color development, resulting in an inability to form a dense cross-linked film and effectively fix the dye molecules. This leads to poor rubbing fastness of the dried fabric, difficulty in rapid winding, color staining, and the inability to fix any remaining dye after color development, resulting in problems with wash fastness and rubbing fastness.

[0017] A further option is that the disperse dye direct-to-garment ink also includes a humectant selected from at least one of glycerol, diethylene glycol, ethylene glycol, and 1,2-propanediol.

[0018] Humectants slow down ink evaporation, maintain stable viscosity, prevent printhead clogging due to drying, ensure smooth ink flow, and improve ink storage and usage stability.

[0019] A further option is that the disperse dye direct-to-garment ink also includes a surfactant, which is a nonionic surfactant, including at least one of acetylenic diol ethoxylate, modified organosiloxane, and polyether siloxane copolymer.

[0020] Adding nonionic surfactants such as acetylacetonate diol ethoxylates can significantly reduce the surface tension of the ink, improve its wetting and spreading properties on fabrics, and further prevent bleeding from damaging the pattern accuracy.

[0021] A further option is to select disperse dyes in disperse dye pastes from low-temperature disperse dyes, medium-temperature disperse dyes, or high-temperature disperse dyes.

[0022] The disperse dye paste can be selected from low-temperature, medium-temperature, or high-temperature disperse dyes. The ink system of this invention can be flexibly adapted to the needs of various scenarios and fabric characteristics of direct-to-garment printing, and has strong applicability.

[0023] A further option is that, by weight percentage, disperse dye direct-to-garment ink comprises 20% to 40% disperse dye paste, 3% to 5% self-crosslinking agent, 1% to 2% penetrant, 5% to 8% humectant, 15% to 25% humectant, 0.5% to 2% surfactant, 0.1% to 0.3% additives, and the balance being water.

[0024] At this ratio, the components of the disperse dye direct-to-ink ink work synergistically to achieve a precise balance between performance and cost, taking into account the overall requirements of high color fastness and smooth printing, while improving process efficiency and economy.

[0025] To achieve the second objective mentioned above, the present invention provides a process for direct-to-garment printing of disperse dye ink, comprising the following steps: printing disperse dye ink onto a fabric, followed by drying, and then performing a color development process to obtain a fabric with digital printing; wherein the disperse dye ink is a high-color-fastness disperse dye ink as described in any of the above embodiments; the drying temperature is not lower than 60°C; and the internal humidity during the color development process is 80%~100%.

[0026] The aforementioned direct-to-garment printing process eliminates pre- and post-treatment steps, simplifying the process flow, controlling production costs, and significantly reducing environmental pollution. The drying temperature is no lower than 60℃ to ensure the self-crosslinking agent reaches its film-forming temperature. Too low a temperature would prevent the ink from drying properly, causing the image to stick to the fabric during transfer and rendering it unusable. Furthermore, the crosslinking agent would not form a dense crosslinked film, thus failing to fix the dye molecules. A further optimized drying temperature is 60℃~80℃. Within this range, the self-crosslinking agent can form a film while simultaneously drying moisture without excessive energy consumption, achieving the best effect in improving rubbing fastness. During the color development process, the internal humidity is maintained at 80%~100%, ensuring the penetrant and hygroscopic agent work together. This allows the ink on the fabric to absorb water vapor and, through the action of the penetrant, quickly wet and penetrate the fabric, achieving uniform dyeing and high color fastness.

[0027] To achieve the third objective mentioned above, the present invention provides a method for preparing a high-colorfastness disperse dye direct-injection ink, which is used to prepare the high-colorfastness disperse dye direct-injection ink described in the above scheme. The preparation method includes the following steps: S1: Mixing disperse dye paste, penetrant, humectant, surfactant, humectant, auxiliary agent and deionized water, and stirring evenly to obtain a first mixture; S2: Adding a self-crosslinking agent to the first mixture and stirring evenly, during this process, controlling the temperature of the first mixture to be lower than the self-crosslinking temperature of the self-crosslinking agent to obtain a second mixture; S3: Filtering the second mixture while keeping the temperature lower than the self-crosslinking temperature of the self-crosslinking agent, thereby obtaining the high-colorfastness disperse dye direct-injection ink.

[0028] During the above preparation process, the temperature is kept below the self-crosslinking temperature of the self-crosslinking agent to ensure that the self-crosslinking agent will not crosslink during the ink preparation process, thus ensuring the subsequent use of the ink. Detailed Implementation

[0029] This invention provides a high color fastness disperse dye direct-to-garment ink, which, by mass percentage, comprises 20% to 40% disperse dye pigment, 3% to 5% self-crosslinking agent, 1% to 2% penetrant, 5% to 8% hygroscopic agent, 15% to 25% humectant, 0.5% to 2% surfactant, 0.1% to 0.3% additives, and the balance being water.

[0030] The disperse dye pastes can be selected from low-temperature, medium-temperature, or high-temperature disperse dyes, specifically from Disperse Red 343, Disperse Red 239, Disperse Red 240, Disperse Red 179, Disperse Red 191, Disperse Blue 5, Disperse Blue 72, Disperse Blue 35, Disperse Blue 26, Disperse Blue 81, Disperse Blue 55, Disperse Yellow 54, Disperse Yellow 51, Disperse Yellow 60, Disperse Yellow 42, Disperse Yellow 186, and Disperse Yellow 126, etc. The self-crosslinking agent is selected from resins with a self-crosslinking temperature of 45℃~60℃, preferably an aqueous self-crosslinking acrylic copolymer emulsion, such as Joncryl from BASF. The following raw materials are used: HD1092 from Walsin Chemical Company (USA), AC2524, AC2742, and AC3660 from Opaldi (Germany); the preferred penetrant is mannitol; the preferred hygroscopic agent is urea; the humectant is selected from at least one of glycerol, diethylene glycol, ethylene glycol, and 1,2-propanediol; the surfactant is a nonionic surfactant, including at least one of acetylenol ethoxylates, modified organosiloxanes, and polyether siloxane copolymers, such as Surfynol 465, Surfynol 61, and Surfynol 485 from Air Chemical Company, TEGO WET260 and TEGO WET270 from TIG Company, and BYK-333 and BYK-387 from BYK Chemical Company; the adjuvant can be a bactericide, which can be selected from BIT (1,2-benzisothiazol-3-one) as needed. All of the above raw materials are commercially available.

[0031] The preparation method of the above-mentioned high color fastness disperse dye direct-injection ink includes the following steps: S1: Mix disperse dye paste, penetrant, hygroscopic agent, surfactant, humectant, auxiliary agent and deionized water in proportion, stir evenly to obtain the first mixture; S2: Add a self-crosslinking agent to the first mixture and stir until homogeneous. During this process, control the temperature of the first mixture to be lower than the self-crosslinking temperature of the self-crosslinking agent to obtain the second mixture. S3: Filter the second mixture while keeping the temperature below the self-crosslinking temperature of the self-crosslinking agent to obtain a disperse dye direct-injection ink with high color fastness.

[0032] Preferably, during the preparation process, the preparation temperature is below 45°C, and the filtration is performed through a 0.5μm pore size filter membrane or filter element.

[0033] A process for direct-to-garment printing of disperse dye inks can be achieved using the aforementioned high color fastness disperse dye direct-to-garment inks. This process includes the following steps: High-color-fastness disperse dye direct-injection ink is directly printed onto the fabric, followed by drying. After drying, a color-development process is performed to directly obtain fabric with digital printing, meaning that pre-treatment sizing and post-treatment washing are unnecessary. The drying temperature is not lower than 60℃, preferably 60℃~80℃; during the color-development process, water vapor is introduced to maintain the internal humidity at 80%~100%, the color-development temperature is 180℃~200℃, and the color-development time is 3min~6min. After drying, the fabric can be rolled up and subjected to high-temperature color development in a steaming machine.

[0034] The present invention will be further described below with reference to specific embodiments and comparative examples.

[0035] Disperse dye direct-injection inks were prepared according to the component contents in Table 1 of the example.

[0036] Table 1

[0037] Prepare comparative examples of disperse dye direct-injection inks according to the component contents in Tables 2 to 4.

[0038] Table 2

[0039] Table 3

[0040] Table 4

[0041] In Comparative Example 28, the self-crosslinking agent was replaced with DSM's waterborne self-crosslinking acrylic resin NeoCRYL A-1127 (self-crosslinking temperature 7°C); in Comparative Example 29, the self-crosslinking agent was replaced with BASF's waterborne self-crosslinking acrylic resin Joncryl® 1908 (self-crosslinking temperature 70°C); in Comparative Example 30, the self-crosslinking agent was replaced with Wanhua's waterborne polyurethane Lacper 4219 (self-crosslinking temperature 48°C); and in Comparative Example 31, no self-crosslinking agent, penetrant, or hygroscopic agent was added.

[0042] During the preparation process, dried ink was observed on the stirring and filtering containers and filter membrane of Comparative Example 28, indicating that the ink of Comparative Example 28 forms a film at room temperature and in a relatively fast time. It is judged that printing with this ink will cause printhead clogging. Therefore, Comparative Example 28 will not be subjected to subsequent printing experiments.

[0043] The inks of Examples 1 to 11 and Comparative Examples 1 to 27 were used to print 100% solid color samples on unsized polyester fabric using an EPSON S3200 A2 printhead printer. The samples were dried at 70°C and then subjected to high-temperature color development at 200°C for 3 minutes, with humidity controlled at 80% to 100%. After color development, a semi-finished fabric with printing was obtained. Application Examples 1 to 38 were obtained.

[0044] Application Example 39 The ink from Example 1 was used to print 100% solid color blocks on an EPSON S3200 A2 printhead printer. The prints were then applied to unsized polyester fabric. The drying temperature was set at 70°C, followed by a 3-minute high-temperature color development process at 200°C. No steam was added and the humidity was not controlled. After color development, a semi-finished fabric with the print was obtained.

[0045] The inks used in Comparative Examples 29 to 31 were used to print 100% solid color samples on unsized polyester fabric using an EPSON S3200 A2 printhead printer. The samples were dried at 70°C and then subjected to a high-temperature color development process at 200°C for 3 minutes, with humidity controlled between 80% and 100%. This resulted in semi-finished fabric with the printed pattern. Application Examples 40 to 42 were obtained.

[0046] Commercially available inks were used to print 100% solid color samples on unsized polyester fabric using an EPSON S3200 A2 printhead printer. The samples were then dried at 70°C and subjected to a high-temperature color development process at 200°C for 3 minutes, with humidity controlled between 80% and 100%. The resulting semi-finished fabric with the printed design was then obtained. This is application example 43.

[0047] The semi-finished fabrics obtained from Examples 1 to 43 were tested for rubbing fastness, washing fastness, clarity, and color performance. The inks from Examples 1 to 11, Comparative Examples 1 to 27, and Comparative Examples 29 and 30 were tested for moisture retention and jetting stability. The test methods are as follows: I. Test method for friction fastness: Refer to GB / T 3920-2008 "Textiles - Tests for color fastness - Color fastness to rubbing"; ISO 105-X12-2001 "Textiles - Tests for color fastness - Color fastness to rubbing" Procedure.

[0048] The criteria for judging the rubbing fastness of the dried sample fabric are as follows: If the result is level 3 or higher, it is judged as A; if the result is level 2-3, it is judged as B; if the result is level less than 2, it is judged as C.

[0049] The criteria for judging the rubbing fastness of the sample fabric after high-temperature color development are as follows: If the result is level 4 or higher, it is judged as A; if the result is level 3-4, it is judged as B; if the result is level 3 or lower, it is judged as C.

[0050] II. Test method for wash fastness: Refer to GB / T 3921-2008 "Textiles - Tests for color fastness - Color fastness to washing"; ISO 105-C10:2006 "Tests for color fastness C10: Color fastness to washing with soap or soap and baking soda" procedure.

[0051] If the result is level 4 or higher, it is judged as A; if the result is level 3-4, it is judged as B; if the result is level 3 or lower, it is judged as C.

[0052] III. Methods for testing sharpness: On the semi-finished fabrics of Application Examples 1 to 43, the edges of selected spots of the same color were observed with a 10x electronic magnifying glass. If the edges were clearly visible and showed no seepage, it was judged as A; if there was slight seepage, it was judged as B; and if the seepage was obvious or severe, it was judged as C.

[0053] IV. Methods for Measuring Color Expression To test the uniformity of color on the fabric after ink development, on the semi-finished fabrics of Application Examples 1 to 43, the color density of 9 points was tested on a pure color patch of the same color. The distance between each point was ≥1 cm. The maximum color density minus the minimum color density was judged as follows: if the result was less than or equal to 0.1, it was judged as A; if the result was greater than 0.1 and less than or equal to 0.3, it was judged as B; and if the result was greater than 0.3, it was judged as C.

[0054] V. Methods for determining moisturizing properties: To test the ink's moisture retention performance on the printhead, under environmental conditions of 30℃ and 40% humidity, ink was loaded into an EPSON S3200 A2 printhead printer. With the printhead intact, the printhead was removed from the machine's moisture retention position and suspended in the air for a certain period of time before testing its condition again. A printhead intact for ≥30 minutes was rated A; 20-30 minutes was rated B; and less than 20 minutes was rated C.

[0055] VI. Methods for determining jet stability The stability of continuous ink ejection in printers for Examples 1 to 11, Comparative Examples 1 to 27, and Comparative Examples 29 to 30 was assessed by loading ink into an EPSON S3200 A2 printhead and printing 500 meters of ink at 100% ink volume using a 1-pass setting. The number of broken holes before and after printing was compared. A result of less than or equal to 1 hole was classified as A; a result of more than 1 hole but less than or equal to 5 holes was classified as B; and a result of more than 5 holes was classified as C.

[0056] VII. Method for determining the effective ink volume of a printer 1. Printing the same amount of ink, after final processing, yields effective color performance, reflected in color density and color difference between the front and back sides.

[0057] Example 1 was used to print 50% and 100% ink volume monochrome color blocks on unsized polyester fabric using an EPSON S3200 A2 printhead printer. The drying temperature was set at 70°C, followed by high-temperature color development at 200°C for 3 minutes, with humidity controlled at 80%~100%. The resulting semi-finished fabric with the print was then obtained. The color density of the front and back sides of the fabric was tested. This is shown in Table 7 as Application Example 1.

[0058] Comparative Example 31 (without self-crosslinking agent, penetrant, or urea) was printed with 50% and 100% ink volume monochrome color blocks on unsized polyester fabric using an EPSON S3200 A2 printhead printer. The printing was done at 70°C, followed by a 3-minute high-temperature color development process at 200°C, with humidity controlled between 80% and 100%. The resulting semi-finished fabric with the print was then tested. The color density of the front and back sides of the fabric was measured. This is shown in Table 7 as Application Example 42.

[0059] Commercially available products were printed with 50% and 100% ink volume monochrome color blocks on unsized polyester fabric using an EPSON S3200 A2 printhead printer. The fabric was dried at 70°C, then subjected to a high-temperature color development process at 200°C for 3 minutes, with humidity controlled between 80% and 100%. This resulted in a semi-finished fabric with the printed pattern. The color density of the fabric's front and back sides was tested. The results are shown in Table 7 as Application Example 43.

[0060] Divide the reverse color density of the two sets of data by the front color density to obtain the percentage. If the result is greater than or equal to 70%, the rating is A; if the result is less than 70% but greater than 50%, the rating is B; if the result is less than 50% but greater than 30%, the rating is C; and if the result is less than 30%, the rating is D.

[0061] 2. By adjusting the ink volume, after final processing, the required ink volume is to achieve a front-side color density greater than or equal to 1.5, and a back-side color density ratio greater than or equal to 70% compared to the front-side.

[0062] Example 1 involved printing 50%-150% ink volume monochrome color patches on unsized polyester fabric using an EPSON S3200 A2 printhead. The drying temperature was set at 70°C, followed by a 3-minute high-temperature color development process at 200°C, with humidity controlled at 80%-100%. The resulting semi-finished fabric with the print was then obtained. The color density of the front and back sides of the fabric was tested and is shown in Table 7 as Application Example 1.

[0063] Comparative Example 31 (without self-crosslinking agent, penetrant, or urea) was printed with 50%-150% ink volume monochrome color blocks on unsized polyester fabric using an EPSON S3200 A2 printhead. The printing was done at 70°C, followed by a 3-minute high-temperature color development process at 200°C, with humidity controlled at 80%-100%. The resulting semi-finished fabric with the print was then tested. The color density of the fabric's front and back sides was measured. This is shown in Table 7 as Application Example 42.

[0064] Commercially available products were printed with 50%-150% ink volume monochrome color blocks on unsized polyester fabric using an EPSON S3200 A2 printhead printer. The fabric was dried at 70°C, then subjected to a 3-minute high-temperature color development process at 200°C, with humidity controlled at 80%-100%. This resulted in a semi-finished fabric with the printed design. The color density of the fabric's front and back sides was tested. This is shown in Table 7 as Application Example 43.

[0065] For the two sets of data above, if the front color density is greater than or equal to 1.5, and the color density difference between the back and front is greater than or equal to 70%, and the required ink volume is less than or equal to 100%, the rating is A; if the required ink volume is greater than 100% and less than or equal to 120%, the rating is B; if the required ink volume is greater than 120% and less than or equal to 150%, the rating is C; and if the required ink volume is greater than 150%, the rating is D.

[0066] The test results are shown in Tables 5, 6, and 7 below.

[0067] Table 5

[0068] Table 6

[0069] Table 7

[0070] As can be seen from Tables 1 to 7, the ink in Application Example 12 does not contain a self-crosslinking agent, the ink in Application Example 13 does not contain a penetrant, the ink in Application Example 14 does not contain a hygroscopic agent, the inks in Application Examples 15 to 18 have high self-crosslinking agent content, the inks in Application Examples 19 to 22 have low self-crosslinking agent content, the inks in Application Examples 23, 24, 27, and 28 have high penetrant content, the inks in Application Examples 25, 26, 29, and 30 have low penetrant content, the inks in Application Examples 31, 33, 35, and 37 have high hygroscopic agent content, the inks in Application Examples 32, 34, 36, and 38 have low hygroscopic agent content, the printing process in Application Example 39 does not add steam and does not control humidity, the self-crosslinking agents in the inks of Application Examples 40 and 41 do not meet the requirements, Application Example 42 does not contain a self-crosslinking agent, hygroscopic agent, or penetrant, and Application Example 43 uses a commercially available product. The performance of these inks was inferior to that of the inks used in Application Examples 1 to 11 in preparing the semi-finished fabrics. Some inks in Comparative Examples 1 to 30 also showed inferior performance in terms of moisture retention and printing stability compared to Examples 1 to 11. As can be seen from Table 7, the ink in Example 1 had a better color density and required ink volume than Comparative Example 31 and commercially available products.

[0071] The disperse dye direct-jet inks provided in Application Examples 1 to 11 of this invention simultaneously include appropriate amounts of crosslinking agent, penetrant, and hygroscopic agent. The self-crosslinking agent has a moderate self-crosslinking temperature, facilitating crosslinking and film formation during the drying stage. This also avoids the problem of low self-crosslinking temperatures causing self-crosslinking during the preparation stage, which could affect subsequent use. During the drying stage, the self-crosslinking agent undergoes a crosslinking reaction on the fiber surface, forming a dense crosslinked film. This self-formed crosslinked film creates a three-dimensional network structure, significantly improving the mechanical properties of the inkjet coating. This effectively fixes dye molecules, improves rubbing fastness, and prevents staining caused by fabric friction during the drying and winding stages. In the subsequent high-temperature color development stage, the self-crosslinking agent continues to stabilize dye molecules. Combined with the effects of the penetrant and hygroscopic agent, this reduces color floating and improves color fastness. Specifically, during the high-temperature color development stage, the hygroscopic agent absorbs water vapor, and then, through the action of the penetrant, quickly wets and penetrates into the fabric. The self-crosslinking agent stabilizes the dye molecules, ensuring uniform dyeing and complete dye-fabric bonding. This results in high color fastness after color development, preventing white showing and guaranteeing excellent pattern clarity and color performance. Because the combined action of the penetrant and hygroscopic agent ensures rapid wetting and penetration during the color development stage, additional penetration is no longer needed during the printing stage. Only the basic ink amount required for the printed pattern needs to be achieved, thus ensuring that the ink amount does not exceed the fabric's bonding limit and preventing ink floating. Furthermore, with the appropriate ink amount, the ink penetration is greatly controlled with the help of the film-forming effect of the self-crosslinking agent, reducing or eliminating the pretreatment sizing process while still achieving a clear pattern. In summary, under the combined action of the self-crosslinking agent, penetrant, and hygroscopic agent, the disperse dye direct-injection ink of this invention, when printed onto fabric, exhibits high rubbing fastness, high wash fastness, excellent pattern clarity, and superior color performance. Simultaneously, it eliminates the need for pretreatment sizing and post-treatment washing processes, simplifying the process flow, controlling production costs, and significantly reducing environmental pollution.

[0072] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A high color fastness disperse dye direct-to-garment ink, comprising disperse dye paste, characterized in that: The disperse dye direct-injection ink also includes a self-crosslinking agent, a penetrant, and a hygroscopic agent; The self-crosslinking agent is selected from resins with a self-crosslinking temperature of 45℃ to 60℃.

2. The high color fastness disperse dye direct-injection ink as described in claim 1, characterized in that: The penetrant is selected from mannitol, and by mass percentage, the penetrant accounts for 1% to 2% of the disperse dye direct-injection ink.

3. The high color fastness disperse dye direct-injection ink as described in claim 1, characterized in that: The hygroscopic agent is selected from urea, and by mass percentage, the hygroscopic agent accounts for 5% to 8% of the disperse dye direct-injection ink.

4. The high color fastness disperse dye direct-injection ink as described in claim 1, characterized in that: The self-crosslinking agent is selected from water-based self-crosslinking acrylic copolymer emulsion, and by mass percentage, the self-crosslinking agent accounts for 3% to 5% of the disperse dye direct-injection ink.

5. A high color fastness disperse dye direct-injection ink as described in any one of claims 1 to 4, characterized in that: The disperse dye direct-injection ink further includes a humectant selected from at least one of glycerol, diethylene glycol, ethylene glycol, and 1,2-propanediol.

6. A high color fastness disperse dye direct-injection ink as described in any one of claims 1 to 4, characterized in that: The disperse dye direct-injection ink also includes a surfactant, which is a nonionic surfactant, and the nonionic surfactant includes at least one of acetylenic diol ethoxylate, modified organosiloxane, and polyether siloxane copolymer.

7. A high color fastness disperse dye direct-injection ink as described in any one of claims 1 to 4, characterized in that: The disperse dyes in the disperse dye paste are selected from low-temperature disperse dyes, medium-temperature disperse dyes, or high-temperature disperse dyes.

8. A high color fastness disperse dye direct-injection ink as described in any one of claims 1 to 4, characterized in that: By weight percentage, the disperse dye direct-injection ink comprises 20% to 40% of the disperse dye pigment, 3% to 5% of the self-crosslinking agent, 1% to 2% of the penetrant, 5% to 8% of the humectant, 15% to 25% of the humectant, 0.5% to 2% of the surfactant, 0.1% to 0.3% of the additives, and the balance being water.

9. A process for direct-to-garment printing with disperse dye inks, characterized in that, Includes the following steps: Disperse dye direct-injection ink is printed onto the fabric, then dried, and after drying, a color development process is carried out to obtain fabric with digital printing. The disperse dye direct-injection ink is a high color fastness disperse dye direct-injection ink as described in any one of claims 1 to 8; The drying temperature shall not be lower than 60°C; The internal humidity during the color development process is 80%~100%.

10. A method for preparing a high-colorfastness disperse dye direct-injection ink, characterized in that, The method for preparing a high color fastness disperse dye direct-injection ink as described in claim 8 includes the following steps: S1: Mix disperse dye paste, penetrant, humectant, surfactant, moisturizer, auxiliaries and deionized water, stir evenly to obtain the first mixture; S2: Add a self-crosslinking agent to the first mixture and stir until homogeneous. During this process, control the temperature of the first mixture to be lower than the self-crosslinking temperature of the self-crosslinking agent to obtain a second mixture. S3: Filter the second mixture while keeping the temperature below the self-crosslinking temperature of the self-crosslinking agent to obtain the high color fastness disperse dye direct injection ink.

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