Sublimation-resistant heat transfer printing ink and preparation method and transfer printing process thereof

Abstract

The invention discloses sublimation-resistant heat transfer printing ink which is good in cloth coloring penetration and not prone to secondary sublimation, a preparation method and a transfer printing process of the sublimation-resistant heat transfer printing ink. The sublimation-resistant heat transfer printing ink is prepared from the following components in percentage by mass: 20%-40% of disperse dye color paste, 25%-35% of an organic solvent, 0.1%-3% of a surfactant, 0.1%-1.5% of a water-based polymer, 0.1%-3% of a defoaming agent, 0.1%-0.5% of an acid-base regulator, 0.1%-2% of a bactericide and the balance of deionized water. The invention is applied to the technical field of digital printing ink jet.

Description

Technical Field

[0001] The present invention relates to the technical field of digital printing inkjet, and in particular to a sublimation-resistant thermal transfer ink, a preparation method thereof, and a transfer process thereof. Background Art

[0002] Digital inkjet printing technology, with its advantages of eliminating the need for platemaking, high intelligence, relatively low water and energy consumption, and minimal pollution, is gradually replacing traditional printing processes and becoming the mainstream development direction of the printing and dyeing industry. Thermal transfer is currently one of the main printing technologies for digital printing. It uses thermal transfer ink to print a pattern on thermal transfer paper using a textile inkjet printer. The pattern is then transferred to the textile fabric through a high-temperature pressing process. This technology offers advantages such as a simple process, environmental friendliness, and vibrant colors after transfer. The resulting textile products can achieve wash fastness levels of 4-5 and wet and dry rubbing fastness levels of 4-5, fully meeting textile standards.

[0003] The thermal transfer inks currently used in the market are basically medium- and low-type disperse dye inks. This type of disperse dye has a low sublimation temperature, small molecular weight, fast dye diffusion rate, and good uniformity. It is suitable as a coloring dye for digital thermal transfer and can meet the requirements of small particle size of thermal transfer inkjet inks, simple and energy-saving transfer process, and bright and uniform coloring. However, textiles made with medium- and low-temperature thermal transfer inks have obvious shortcomings: 1. Insufficient color penetration of the fabric. Since the thermal transfer process is mostly flat pressing, the ink only colors the surface of the fabric, which is prone to yarn turning over and whitening. 2. Fabrics are prone to secondary sublimation during production, transportation, and storage. Due to the low sublimation temperature of medium- and low-type disperse dyes, the sublimation color fastness of the printed products is insufficient, resulting in fading, discoloration, and other problems, which cannot meet the requirements of high-quality orders. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a sublimation-resistant thermal transfer ink with good fabric coloring penetration and low resistance to secondary sublimation, as well as a preparation method and a transfer process thereof.

[0005] The technical solution adopted by the present invention is: the present invention includes a sublimation-resistant thermal transfer ink, a preparation method and a transfer process thereof, wherein the sublimation-resistant thermal transfer ink is composed of the following components in mass percentage: 20%-40% disperse dye paste, 25%-35% organic solvent, 0.1%-3% surfactant, 0.1%-1.5% water-based polymer, 0.1%-3% defoaming agent, 0.1%-0.5% acid-base regulator, 0.1%-2% bactericide, and the balance is deionized water.

[0006] Furthermore, the disperse dye in the disperse dye paste includes at least one of a low-temperature type and a medium-temperature type, and the disperse dye is one or more of disperse red 60, disperse blue 360, disperse yellow 54, disperse brown 27, and disperse blue 359.

[0007] As can be seen from the above technical solution, the low-temperature or medium-temperature disperse dyes selected have a small relative molecular mass and a simple molecular structure. During the milling process, it is easier to achieve the requirement that the inkjet ink particle size is less than 300nm, thereby simplifying the thermal transfer mill paste production process and saving energy. With the help of the dispersant, the disperse dye can exist in a dispersed state in water mainly as tiny particles, is not prone to aggregation and precipitation, and has good thermal transfer ink storage performance. Since the disperse dye dyeing mechanism is that the dye molecules enter the interior of the fiber and are combined with it by hydrogen bonds and van der Waals forces, the low-medium temperature disperse dyes with small molecular mass are more likely to enter the interior of the fiber, have a relatively large affinity for the fiber, have a relatively low temperature requirement for dyeing, and have a fast dyeing diffusion rate.

[0008] Furthermore, the organic solvents are all polyols with a boiling point higher than 220° C., and can be selected from one or more of glycerol, 1,5-pentanediol, diethylene glycol, and dipropylene glycol.

[0009] As can be seen from the above technical solution, the use of an organic solvent with a high boiling point can prevent the thermal transfer ink of the present invention from producing a situation where the dyeing effect of the fabric deteriorates due to solvent evaporation during transfer. The dyeing mechanism of the digital thermal transfer process is that the thermal transfer ink is printed on the transfer paper through a print nozzle. During high-temperature pressing, the temperature is usually 200°C-220°C, and the disperse dye on the transfer paper will change from solid to gaseous, thereby entering the fiber interior of the fabric and combining with it to achieve the dyeing effect. If the boiling point of the organic solvent in the ink is too low, the polyol will also turn into gas along with the dye during transfer, which will hinder the diffusion of the disperse dye into the fiber interior and interfere with the combination between its molecules, resulting in insufficient color penetration of the textile and poor color fastness.

[0010] Furthermore, the surfactant is a combination surfactant of polyether-modified silicone and acetylene glycol, the polyether-modified silicone is BYK-348 or BYK-3451, and the acetylene glycol can be one or more of Evonik's Surfynol 420, Surfynol 465, and Surfynol 485.

[0011] As can be seen from the above technical solutions, the use of polyether-modified silicone surfactants can effectively reduce the surface tension of the ink, allowing the ink to meet the spray requirements of the printhead and prevent slanted spray and ink drift during the printing process. The use of acetylene glycol surfactants can wet the printhead nozzle, improve the wettability of the substrate, prevent shrinkage holes, and improve the printing smoothness of the ink. The present invention uses a combination of these two types of surfactants to enable the thermal transfer ink to effectively maintain good surface tension and have excellent printing smoothness.

[0012] Furthermore, the water-based polymer is a water-soluble polymer, and the water-soluble polymer is at least one of polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP); the polyvinyl pyrrolidone (PVP) is selected from PVP-K30, and the polyvinyl alcohol (PVA) is selected from PVA-205; the present invention requires the use of a water-based polymer with good water solubility, small relative molecular weight, and low viscosity. The degree of alcoholysis of polyvinyl alcohol (PVA-205) is 87%-89%. Experiments have shown that this type of product has the best water solubility and low viscosity of the aqueous solution; and polyvinyl pyrrolidone (PVP) is divided into four grades according to its average molecular weight, which is usually expressed as a K value. Different K values ​​represent the corresponding average molecular weight range of PVP. PVP-K30 is easily soluble in water and has low viscosity. A water-based polymer with a larger molecular weight is prone to flocculation in the ink system, resulting in poor ink stability and nozzle clogging during printing. Experimental verification shows that the water-based polymer selected by the present invention will not have an adverse effect on the thermal transfer ink system.

[0013] As can be seen from the above technical solution, polyvinyl alcohol (PVA) exhibits excellent biocompatibility, non-toxicity, chemical stability, and adjustable crystallinity (mechanical strength). Its molecular chain contains numerous hydroxyl groups, resulting in excellent film-forming, emulsifying, and adhesive properties. Through cross-linking and hydrogen bonding with fibers, it forms a three-dimensional polymer network on the surface of fabric fibers, thereby preventing disperse dyes from escaping the fiber interior due to secondary sublimation. Polyvinyl pyrrolidone (PVP), a synthetic water-soluble polymer, exhibits excellent solubility, physiological compatibility, film-forming, and adhesive properties. PVP has a strong affinity for many organic dyes. The lactam structure in its molecule can bind to organic functional groups such as hydroxyl and amino groups in dyes. It can also bind to hydrophobic synthetic fibers such as polyacrylonitrile, esters, nylon, and fibrous materials, significantly increasing the fiber's binding capacity for disperse dyes. Therefore, the PVA-205 and PVP-K30 selected in the present invention can effectively enhance the affinity of disperse dyes in thermal transfer inks for hydrophobic synthetic fibers, thereby improving their sublimation color fastness. A certain amount of high-molecular-weight polymer protects the stability of the ink dispersion system, encapsulating the dispersed particles within the ink, enhancing thermal stability and improving the ink's dispersibility. By limiting the weight percentage of the water-based polymer to 0.1%-1.5%, the present invention not only further improves the sublimation color fastness of the thermal transfer ink but also ensures the stability of the ink system.

[0014] Furthermore, the defoaming agent is a modified acetylene glycol defoaming agent, and the modified acetylene glycol defoaming agent is at least one of Surfynol DF-110D, Surfynol DF-110C, Surfynol DF-110BC, and Surfynol104BC.

[0015] As can be seen from the above technical solution, traditional silicone defoamers are often difficult to dissolve in water and organic solvents, which can damage the stability of the ink system and affect the ink's filtration performance. Therefore, the present invention uses a modified acetylene glycol defoamer that is less destructive to the ink dispersion system.

[0016] Furthermore, the acid-base regulator is an organic weak acid containing a carboxyl group, and the organic weak acid is acetic acid.

[0017] As can be seen from the above technical solution, disperse dyes are acid-resistant but not alkali-resistant. Under high-temperature alkaline conditions, certain groups in the disperse dye molecules will hydrolyze or be reduced, causing the dye structure to change, resulting in a lighter or darker color. This reduces the ink transfer efficiency and poor color penetration. Therefore, it is necessary to maintain the pH value of the thermal transfer ink at a neutral or slightly acidic level. The present invention achieves a stable pH adjustment effect by adding 0.1% to 0.5% by weight of acetic acid.

[0018] Furthermore, the bactericide of the present invention can provide a long-lasting broad-spectrum bactericidal effect in the ink storage tank, allowing the ink to have excellent long-term storage performance. The bactericide is preferably PROXEL GXL bactericide.

[0019] Furthermore, a method for preparing the sublimation-resistant thermal transfer ink comprises the following steps: adding 20%-40% disperse dye paste, 25%-35% organic solvent, 0.1%-3% surfactant, 0.1%-1.5% water-based polymer, 0.1%-3% defoaming agent, 0.1%-0.5% acid-base regulator, 0.1%-2% bactericide, and the rest deionized water, a total of 100 parts, into a blender, stirring at a speed of 800 rpm for 40 min-60 min, and then standing and aging for 30 min to obtain an ink mixed solution, filtering with a φ0.45 μm filter membrane and a φ0.22 μm filter membrane respectively to obtain a sublimation-resistant thermal transfer ink.

[0020] Furthermore, a transfer process is provided, in which the sublimation-resistant thermal transfer ink prepared by the preparation method is added into a printer, and then a pattern is printed on thermal transfer paper by the printer, and then the pattern on the thermal transfer paper is transferred to the textile fabric through a high-temperature pressing process.

[0021] The beneficial effects of the present invention are: 1. By selecting a high-boiling-point polyol as the organic solvent of the thermal transfer ink, the present invention prevents the ink from being disturbed during high-temperature pressing and transfer, and the disperse dye can be fully combined with the fibers of the textile after sublimation, thereby improving the transfer coloring permeability of the ink and improving the color fastness of the ink.

[0022] 2. By selecting a suitable water-soluble high molecular weight polymer, the present invention enables the thermal transfer ink to cross-link on the transfer fabric to form a three-dimensional polymer network, allowing the disperse dye to be fully bound inside the fiber, thereby improving the sublimation color fastness of the textile made with the thermal transfer ink. The textile will not show obvious fading or discoloration during use, transportation, and storage, thus meeting the requirements of high-quality fabrics.

[0023] 3. The present invention adjusts the pH value of the thermal transfer ink by adding an organic weak acid, keeping the ink neutral or weakly acidic, thereby increasing the ink transfer color depth and transfer rate and improving the color penetration effect. DETAILED DESCRIPTION

[0024] In this embodiment, the present invention includes a sublimation-resistant thermal transfer ink, a preparation method, and a transfer process thereof. The sublimation-resistant thermal transfer ink comprises the following components by mass percentage: 20%-40% disperse dye paste, 25%-35% organic solvent, 0.1%-3% surfactant, 0.1%-1.5% water-based polymer, 0.1%-3% defoaming agent, 0.1%-0.5% acid-base regulator, 0.1%-2% bactericide, and the balance is deionized water.

[0025] In this embodiment, the disperse dye in the disperse dye paste includes at least one of a low-temperature type and a medium-temperature type, and the disperse dye is one or more of disperse red 60, disperse blue 360, disperse yellow 54, disperse brown 27, and disperse blue 359.

[0026] In this embodiment, the organic solvent is one or more of glycerol, 1,5-pentanediol, diethylene glycol, and dipropylene glycol, and the boiling point of the organic solvent is higher than 220°C.

[0027] In this embodiment, the surfactant is a combination surfactant of polyether-modified silicone and acetylene glycol, the polyether-modified silicone is BYK-348 or BYK-3451, and the acetylene glycol can be one or more of Evonik's Surfynol 420, Surfynol 465, and Surfynol 485.

[0028] In this embodiment, the water-based polymer is a water-soluble polymer, and the water-soluble polymer is at least one of polyvinyl alcohol PVA and polyvinyl pyrrolidone PVP; the polyvinyl alcohol PVA is PVA-205, wherein the alcoholysis degree of the polyvinyl alcohol PVA-205 is 87%-89%; the polyvinyl pyrrolidone PVP is PVP-K30.

[0029] In this embodiment, the defoaming agent is a modified acetylene glycol defoaming agent, and the modified acetylene glycol defoaming agent is at least one of Surfynol DF-110D, Surfynol DF-110C, Surfynol DF-110BC, and Surfynol 104BC.

[0030] In this embodiment, the acid-base regulator is an organic weak acid containing a carboxyl group, and the organic weak acid is acetic acid.

[0031] In this embodiment, the fungicide is preferably PROXEL GXL fungicide.

[0032] Example 1

[0033] This embodiment provides a method for preparing a sublimation-resistant red thermal transfer ink. The specific steps and parameters are as follows: 20 parts of disperse dye paste including Disperse Red 60, 15 parts of propylene glycol, 7.5 parts of 1,5-pentanediol, 7.5 parts of diethylene glycol, 1.5 parts of Surfynol 485, 0.2 parts of BYK-3451, 1 part of PVP-K30, 0.2 parts of acetic acid, 0.1 parts of Surfynol DF-110D, 0.1 parts of PROXEL GXL, and the remainder of deionized water are added to a blender, stirred at 800 rpm for 40-60 minutes, and then allowed to stand for 30 minutes to obtain an ink mixed solution, which is filtered through a 0.45 μm filter membrane and a 0.22 μm filter membrane, respectively, to obtain a thermal transfer ink.

[0034] Example 2

[0035] This embodiment provides a method for preparing a sublimation-resistant red thermal transfer ink. The specific steps and parameters are the same as those in Example 1, except that 0.5 parts of PVA-205 are added instead of PVP-K30.

[0036] Example 3

[0037] This embodiment provides a method for preparing a sublimation-resistant cyan thermal transfer ink. The specific steps and parameters are as follows:

[0038] Take 20 parts of disperse dye paste including Disperse Blue 359 paste, 12 parts of propylene glycol, 6 parts of 1,5-pentanediol, 6 parts of diethylene glycol, 1.5 parts of Surfynol 485, 0.2 parts of BYK-3451, 1 part of PVP-K30, 0.2 parts of acetic acid, 0.1 parts of Surfynol DF-110D, 0.1 parts of PROXEL GXL, and the rest is deionized water, a total of 100 parts are added to a blender, stirred at 800 rpm for 40 min-60 min, and then allowed to stand and age for 30 min to obtain an ink mixed solution, which is filtered with a φ0.45 μm filter membrane and a φ0.22 μm filter membrane respectively to obtain a thermal transfer ink.

[0039] Example 4

[0040] The embodiment provides a method for preparing a sublimation-resistant cyan thermal transfer ink. The specific steps and parameters are the same as those of Example 3, except that 0.5 parts of PVA-205 are added instead of PVP-K30.

[0041] Example 5

[0042] This embodiment provides a method for preparing a sublimation-resistant yellow thermal transfer ink. The specific steps and parameters are as follows:

[0043] Take 20 parts of disperse dye paste including Disperse Yellow 54 paste, 16 parts of propylene glycol, 8 parts of 1,5-pentanediol, 8 parts of diethylene glycol, 1.5 parts of Surfynol 485, 0.2 parts of BYK-3451, 1 part of PVP-K30, 0.2 parts of acetic acid, 0.1 parts of Surfynol DF-110D, 0.1 parts of PROXEL GXL, and the rest is deionized water, a total of 100 parts are added to a blender, stirred at 800 rpm for 40 min-60 min, and then allowed to stand and age for 30 min to obtain an ink mixed solution, which is filtered with a φ0.45 μm filter membrane and a φ0.22 μm filter membrane respectively to obtain a thermal transfer ink.

[0044] Example 6

[0045] This embodiment provides a method for preparing a sublimation-resistant yellow thermal transfer ink. The specific steps and parameters are the same as those in Example 5, except that 0.5 parts of PVA-205 are added instead of PVP-K30.

[0046] Example 7

[0047] This embodiment provides a method for preparing sublimation-resistant black thermal transfer ink. The specific steps and parameters are as follows:

[0048] Take 12 parts of disperse dye paste of Disperse Brown 27 paste, 10 parts of Disperse Blue 360 ​​paste, 2 parts of Disperse Yellow 54 paste, 15 parts of propylene glycol, 7.5 parts of 1,5-pentanediol, 7.5 parts of diethylene glycol, 1.5 parts of Surfynol 485, 0.2 parts of BYK-3451, 1 part of PVP-K30, 0.2 parts of acetic acid, 0.1 parts of Surfynol DF-110D, 0.1 parts of PROXEL GXL, and the rest is deionized water, a total of 100 parts are added to a blender, stirred at 800 rpm for 40 min-60 min, and then allowed to stand and age for 30 min to obtain an ink mixed solution, which is filtered with a φ0.45 μm filter membrane and a φ0.22 μm filter membrane respectively to obtain a thermal transfer ink.

[0049] Example 8

[0050] This embodiment provides a method for preparing a sublimation-resistant black thermal transfer ink. The specific steps and parameters are the same as those in Example 7, except that 0.5 parts of PVA-205 are added instead of PVP-K30.

[0051] Comparative Example 1

[0052] This comparative example provides a method for preparing a red thermal transfer ink. The specific steps and parameters are the same as those in Example 1, except that no water-based polymer PVP-K30 or PVA-205 is added. That is, 20 parts of Disperse Red 60 color paste, 15 parts of propylene glycol, 7.5 parts of 1,5-pentanediol, 7.5 parts of diethylene glycol, 1.5 parts of Surfynol 485, 0.2 parts of BYK-3451, 0.2 parts of acetic acid, 0.1 parts of Surfynol DF-110D, 0.1 parts of PROXEL GXL, and the rest being deionized water are added to a blender, stirred at 800 rpm for 40 min-60 min, and then allowed to stand and age for 30 min to obtain an ink mixed solution, which is filtered through a φ0.45 μm filter membrane and a φ0.22 μm filter membrane, respectively, to obtain a thermal transfer ink.

[0053] Comparative Example 2

[0054] This comparative example provides a method for preparing a cyan thermal transfer ink. The specific steps and parameters are the same as those in Example 3, except that no water-based polymer PVP-K30 or PVA-205 is added.

[0055] Comparative Example 3

[0056] This comparative example provides a method for preparing a yellow thermal transfer ink. The specific steps and parameters are the same as those in Example 5, except that no water-based polymer PVP-K30 or PVA-205 is added.

[0057] Comparative Example 4

[0058] This comparative example provides a method for preparing a black thermal transfer ink. The specific steps and parameters are the same as those in Example 7, except that no water-based polymer PVP-K30 or PVA-205 is added.

[0059] Comparative Example 5

[0060] This comparative example provides a method for preparing a red thermal transfer ink. The specific steps and parameters are the same as those in Example 1, except that the addition amount of PVP-K30 is 5%.

[0061] Comparative Example 6

[0062] This comparative example provides a method for preparing a red thermal transfer ink. The specific steps and parameters are the same as those in Example 2, except that the addition amount of PVA-205 is 2%.

[0063] Comparative Example 7

[0064] This comparative example provides a method for preparing a red thermal transfer ink. The specific steps and parameters are the same as those in Example 1, except that acetic acid is not added.

[0065] 1. Thermal transfer ink performance test

[0066] Printing Fluency Test: The thermal transfer inks prepared according to the proportions of each embodiment and the comparative example were respectively tested on a digital printing machine with an Epsoni 3200 print head. The number of print passes was set to 2, the feathering was 30%, and a 100% solid color block was continuously printed for 300m. 2 , observe the nozzle test mesh status before and after printing, and it is qualified if the broken holes are ≤3 holes.

[0067] Standby performance test: The thermal transfer ink prepared according to the proportions of each embodiment and comparative example was added to the ink cartridge of a digital printing machine with an Epson i3200 printhead. With the printhead test mesh intact, the printhead was placed in the machine's moisturizing ink stack. The machine was shut down for 72 hours, and then a test strip was printed to check the printhead test mesh status.

[0068] Storage Stability Test: 2 kg of thermal transfer ink prepared in each example and comparative example was placed in a 60°C forced air oven and aged for 14 days. The ink viscosity change rate (PI) and surface tension change rate (DI) before and after aging were measured, with both values ​​required to be less than 5% for acceptance. Next, 1 kg of each aged ink was filtered through a stainless steel cup filter equipped with a 0.22 μm filter membrane at a pressure of 0.1 MPa. The first 1 kg of aged ink was filtered, with the filtration time recorded as T1. The second 1 kg of aged ink was then filtered, with the filtration time recorded as T2. The filtration performance of the aged ink after aging was calculated as FI = T1 / T2. A FI > 0.8 was required for acceptance.

[0069] Table 1 Test results of thermal transfer ink

[0070]

[0071] The test results in Table 1 indicate that products prepared using the thermal transfer ink provided by the present invention exhibit excellent printing smoothness, good standby performance, and acceptable storage stability. Comparative Examples 5 and 6 demonstrate that adding more than 2% of a water-soluble polymer significantly degrades the printing smoothness of the thermal transfer ink. Excessive amounts of polymer can easily cause the ink to agglomerate, clogging the printhead, degrading the ink's standby performance, and affecting the ink's storage stability.

[0072] 2. Ink printing performance test

[0073] The transfer process is carried out by using the thermal sublimation inks of Examples 1-8 and Comparative Examples 1-7 prepared by the method of the present invention, and printing 100% pure color blocks on 45g Guanhao thermal transfer paper using a digital printing machine with an Epson i3200 nozzle, and then transferring them to polyester cloth through a pressing machine at a transfer temperature of 220°C and a transfer time of 40s to obtain corresponding thermal transfer textile samples.

[0074] 3. Storage color fastness test

[0075] Each thermal transfer textile sample was laminated with a blank fabric to form a test sample, which was then placed in a forced air drying oven with a 5 kg weight applied to the fabric surface. The sample was kept at 80°C for 7 days. The color change difference ΔE1 before and after the test of the textile sample and the color difference ΔE2 before and after the test of the blank fabric were measured using a spectrophotometer. The samples were graded using the color change sample card (national standard GB250-2008) and the color staining sample card (national standard GB251-2008), with grade 1 being the lowest and grade 5 being the highest.

[0076] 4. Sublimation color fastness test

[0077] Each thermal transfer textile sample was laminated with a blank fabric to form a test sample. The sublimation resistance test was carried out using a flat pressing machine at a temperature of 130°C, a pressure of 0.2 MPa, and a pressing time of 60 seconds. The color change difference △E1 of the textile sample before and after the test and the color staining difference △E2 of the blank fabric before and after the test were measured using a spectrophotometer. The grades were assessed using the color change sample card (national standard GB250-2008) and the color staining sample card (national standard GB251-2008), with grade 1 being the lowest and grade 5 being the highest.

[0078] 5. Color density test

[0079] The thermal transfer textile samples of Example 1, Example 2, and Comparative Example 7 were selected, and the color density OD value of the fabrics was measured using a spectrophotometer. The higher the OD value, the better the ink transfer rate and penetration effect.

[0080] Table 2 Test results of thermal transfer textile samples

[0081]

[0082] Table 3 Color density of the thermal transfer ink of Examples 1-2 and the fabric after transfer of Comparative Example 7

[0083] Examples and Comparative Examples Example 1 Example 2 Comparative Example 7 Color density OD value 1.56 1.52 1.32

[0084] As shown in Table 2, compared to the thermal transfer inks of Comparative Examples 1-4, which do not contain a water-soluble polymer, the inks of Examples 1-8 provided by the present invention exhibit excellent storage color fastness, meeting the requirements for daily use, and sublimation color fastness, meeting the requirements for high-quality textiles, all reaching level 4 or higher. Therefore, adding an appropriate amount of water-based polymer can improve the storage and sublimation color fastness of thermal transfer inks.

[0085] Table 3 shows that adding an appropriate amount of acetic acid can improve the color density of the fabric after thermal transfer ink transfer. Alkaline inks can damage the coloring efficiency of disperse dyes, so adjusting the pH value of thermal transfer inks can effectively improve the transfer rate and penetration of inks.

[0086] Although the embodiments of the present invention are described with practical solutions, they do not limit the meaning of the present invention. For those skilled in the art, it is obvious to modify the implementation scheme and combine it with other solutions based on this description.

Claims

1. A sublimation-resistant thermal transfer ink, characterized by: The invention comprises the following components in percentage by mass: 20%-40% of disperse dye paste, 25%-35% of organic solvent, 0.1%-3% of surfactant, 0.1%-1.5% of water-based polymer, 0.1%-3% of defoaming agent, 0.1%-0.5% of acid-base regulator, 0.1%-2% of bactericide, and the balance is deionized water.

2. The sublimation-resistant thermal transfer ink according to claim 1, characterized in that: The disperse dye in the disperse dye paste includes at least one of a low-temperature type and a medium-temperature type, and the disperse dye is one or more of disperse red 60, disperse blue 360, disperse yellow 54, disperse brown 27, and disperse blue 359.

3. The sublimation-resistant thermal transfer ink according to claim 1, characterized in that: The organic solvent is one or more of glycerol, 1,5-pentanediol, diethylene glycol, and dipropylene glycol, and the boiling point of the organic solvent is higher than 220°C.

4. The sublimation-resistant thermal transfer ink according to claim 1, characterized in that: The surfactant is a combination surfactant of polyether-modified silicone and acetylene glycol, the polyether-modified silicone is BYK-348 or BYK-3451, and the acetylene glycol can be one or more of Evonik's Surfynol 420, Surfynol 465, and Surfynol 485.

5. The sublimation-resistant thermal transfer ink according to claim 1, characterized in that: The water-based polymer is a water-soluble high molecular polymer, and the water-soluble high molecular polymer is at least one of polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP). The polyvinyl alcohol (PVA) is PVA-205, and the alcoholysis degree of PVA-205 is 87%-89%. The polyvinyl pyrrolidone (PVP) is PVP-K30.

6. The sublimation-resistant thermal transfer ink according to claim 1, characterized in that: The defoaming agent is a modified acetylene glycol defoaming agent, and the modified acetylene glycol defoaming agent is at least one of Surfynol DF-110D, Surfynol DF-110C, Surfynol DF-110BC, and Surfynol 104BC.

7. The sublimation-resistant thermal transfer ink according to claim 1, characterized in that: The acid-base regulator is an organic weak acid containing a carboxyl group, and the organic weak acid is acetic acid.

8. The sublimation-resistant thermal transfer ink according to claim 1, characterized in that: The fungicide is preferably PROXEL GXL fungicide.

9. A method for preparing the sublimation-resistant thermal transfer ink according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: adding 20%-40% of disperse dye paste, 25%-35% of organic solvent, 0.1%-3% of surfactant, 0.1%-1.5% of water-based polymer, 0.1%-3% of defoaming agent, 0.1%-0.5% of acid-base regulator, 0.1%-2% of bactericide and the remainder of deionized water, a total of 100 parts into a blender, stirring at a speed of 800 rpm for 40 minutes to 60 minutes, then standing and aging the mixture for 30 minutes to obtain an ink mixed solution, filtering the mixture with a φ0.45um filter membrane and a φ0.22um filter membrane respectively to obtain sublimation-resistant thermal transfer ink.

10. A transfer process, characterized in that: The sublimation-resistant thermal transfer ink prepared by the preparation method described in claim 9 is added to a printer, and then the pattern is printed on thermal transfer paper by the printer, and then the pattern on the thermal transfer paper is transferred to the textile fabric through a high-temperature pressing process.

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