A water-based digital printing sublimation ink

Abstract

The invention discloses a water-based digital printing sublimation ink, and relates to the technical field of digital printing. A water-based digital printing sublimation ink comprises the following raw materials by weight: 60-80 parts of aqueous solvent, 5-30 parts of nano-color paste, 0.1-3 parts of wetting agent, 1-10 parts of emulsifying thickener, 0.1-1 parts of pH regulator II, and 0.1-1 parts of bactericidal preservative. By adding a wetting agent and an emulsifying thickener, not only the ink has good printing fluency and stability, the sublimation ink is not easy to clog the nozzle during high-speed printing, and the occurrence of broken holes during printing is reduced, but also the quick-drying property of the ink is greatly improved, so that the sublimation ink can dry quickly after transfer, and prevent the ink from blurring and diffusing during the transfer and drying process, which is conducive to improving the sharpness of printing and reducing the sense of grain, and improving the printing effect.

Description

Technical Field

[0001] The invention relates to the technical field of water-based inks, and in particular to a water-based digital printing sublimation ink. Background Art

[0002] Dye-sublimation ink, also known as thermal transfer ink, is mainly used for heated transfer printing products. General dye-sublimation ink can print patterns on transfer paper through an inkjet printer, and then transfer the patterns or texts to products of other materials in a short time by heating. For this reason, dye-sublimation ink is very suitable for the market demand for personalized customization.

[0003] At present, most thermal sublimation inks are formulated using disperse dyes for textiles, which give thermal sublimation inks saturated colors and good weather resistance. However, existing thermal sublimation inks often cause the nozzles of inkjet printers to become clogged during use, and problems such as broken holes and poor fluidity occur. In addition, existing thermal sublimation inks dry slowly during high-speed printing and are not stable enough, so that the ink is easily blurred and diffused after printing, and the sharpness is insufficient and the granularity is obvious, which directly affects the yield of the textile printing process and causes huge losses to users. Therefore, it is of great significance to improve the formula of thermal sublimation inks to overcome the shortcomings of existing thermal sublimation inks. Summary of the invention

[0004] In order to improve the fluency and stability of thermal sublimation ink during high-speed printing, accelerate the drying speed of thermal sublimation ink printing, improve printing sharpness and reduce granularity, the present application provides a water-based digital printing thermal sublimation ink.

[0005] In the first aspect, the present application provides a water-based digital printing sublimation ink using the following technical solution:

[0006] A water-based digital printing sublimation ink comprises the following raw materials in parts by weight:

[0007] Aqueous solvent: 60-80 parts;

[0008] Nano color paste: 5-30 parts;

[0009] Wetting agent: 0.1-3 parts;

[0010] Emulsifying thickener: 1-10 parts;

[0011] pH regulator II: 0.1-1 part;

[0012] Bactericidal preservative: 0.1-1 part;

[0013] Optionally, the wetting agent is a mixture of two or three wetting agents selected from the group consisting of organically modified polysiloxane, polyamide wax-oxidized polyethylene condensate and nonionic surfactant, specifically a mixture of two or three wetting agents selected from the group consisting of AFCONA 3522, AFCON 3580, AFCON 3581, AFCONA 3585, METOLAT 355, METOLA 362, METOLAT 364, METOLA 365, TERIC 324, TERIC168, TERIC 169 and SURFONIC LF-37;

[0014] Optionally, the emulsifying thickener is selected from one or a mixture of polyvinyl pyrrolidone or polyurethane thickeners, specifically a mixture of one or two of PVP-K10, PVP-K20, PVP-K30, PVP-K40, PVP-K50, and TEGO Viscoplus 3000, TEGO Viscoplus 3010, TEGO Viscoplus 3030.

[0015] By adopting the above technical scheme, the viscosity and surface tension of the thermal sublimation ink are adjusted by using a wetting agent, and the water-oil balance in the ink is controlled, which is beneficial to improving the fluidity and stability of the thermal sublimation ink, making it difficult for the thermal sublimation ink to clog the nozzle during high-speed printing, reducing the occurrence of broken holes during the printing process, and further reducing the printing broken hole rate; using an emulsifying thickener to thicken and dissolve the ink is beneficial to making the nano-color paste fully dissolved in the aqueous solvent and evenly dispersed, which not only makes the ink evenly colored, but also helps to improve the quick-drying property of the ink, so that the thermal sublimation ink can dry quickly after transfer, preventing the ink from blurring during the transfer and drying process, thereby improving the sharpness of the print and reducing the granularity, and improving the transfer effect.

[0016] Optionally, the nano color paste includes the following raw materials in parts by weight:

[0017] Deionized water: 20-50 parts;

[0018] Dispersed color powder: 10-20 parts;

[0019] Dispersant: 5-10 parts;

[0020] Dispersant: 1-3 parts;

[0021] Moisturizer: 10-20 parts;

[0022] Defoaming agent: 0.1-0.3 parts;

[0023] pH regulator I: 0.1-0.3 parts;

[0024] Fungicide: 0.1-0.3 parts;

[0025] Wherein, the dispersant is selected from any one of sulfomethylated lignin, carboxymethylated sodium lignin sulfonate or naphthalene sulfonate dispersants.

[0026] By adopting the above technical scheme, a protective layer can be formed on the surface of the dispersed color powder by using the dispersant, and the electrostatic repulsion or steric hindrance between the dispersants can prevent the dispersed color powder from agglomerating with each other, so that the dispersed color powder can be quickly dispersed in deionized water to form a uniform and stable colloidal suspension, so that the nano-color paste can be evenly colored, which is beneficial to make the color of the prepared ink saturated and improve the printing effect.

[0027] Optionally, the dispersant is carboxymethylated sodium lignin sulfonate, and the carboxymethylated sodium lignin sulfonate comprises the following preparation steps:

[0028] B1. A certain amount of lignin, alkaline solution and deionized water are prepared into a mixed solution with a lignin mass fraction of 25%-30% and a pH value of 10-12, and then a certain amount of sodium sulfite and formaldehyde are added, and the temperature is raised to 160-200° C. in a sealed state to react for 4-5 hours to obtain sulfomethylated lignin;

[0029] B2, using alkaline solution and deionized water to adjust the sulfomethylated sodium lignin sulfonate obtained in step S1 into a mixed solution with an effective ingredient of 30% of sodium lignin sulfonate and a pH value of 10.5-13.5, then raising the temperature to 60-80 ° C, slowly adding a certain amount of chloroacetic acid within a certain period of time, and after the addition is completed, continue to maintain the temperature for 90-120 minutes to obtain carboxymethylated sodium lignin sulfonate.

[0030] By adopting the above technical solution, since sodium carboxymethyl lignin sulfonate has good high-temperature stability, using sodium carboxymethyl lignin sulfonate as a dispersant for nano-color paste is beneficial to keeping the thermal sublimation ink stable during the transfer and drying process, which is not only beneficial to making the thermal sublimation ink uniformly colored after drying, but also beneficial to improving the sharpness of the pattern.

[0031] Optionally, the nano color paste comprises the following preparation steps:

[0032] C1. First, half of the weight of deionized water and the moisturizer are fully stirred, and then the dispersant, the co-dispersant, the defoamer, the bactericide and the pH adjuster I are added and stirred again to obtain a master batch A; then the other half of the weight of the deionized water and the dispersed color powder are stirred and mixed to obtain a master batch B;

[0033] C2, continuously stirring the masterbatch A prepared in step C1, and then slowly adding the masterbatch B during the stirring process to fully mix the masterbatch A and the masterbatch B to form a uniformly dispersed mixed solution, and then stirring and dispersing the mixed solution at a high speed for 120-150 minutes to obtain a pre-treated solution;

[0034] C3. Grind the pretreatment liquid obtained in step C2 for multiple cycles until the average particle size of the material is D50≤120nm and D90≤250nm, thereby obtaining a nano color paste.

[0035] By adopting the above technical scheme, it is beneficial to fully disperse the dispersed color powder in the pretreatment liquid. Secondly, the pretreatment liquid containing the dispersed color powder is subjected to multiple cycles of grinding, which is beneficial to reducing large particles in the nano-color paste, making the nano-color paste delicate and smooth, and facilitating further uniform dispersion of the nano-color paste in the aqueous solvent.

[0036] Optionally, the aqueous solvent includes deionized water and an auxiliary solvent, the mixing ratio of the deionized water to the auxiliary solvent is 1:(0.2-1.3), and the auxiliary solvent is a mixture of one or more water-soluble solvents of alcohols and ethers with a boiling point below 300°C.

[0037] Furthermore, the auxiliary solvent is selected from at least one or more combinations of ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,5-pentanediol, polyvinyl alcohol, sorbitol, polyethylene glycol-400, polyethylene glycol-600, polyethylene glycol-800, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol ethyl ether, diethylene glycol monobutyl ether or triethylene glycol butyl ether.

[0038] By adopting the above technical solution, the auxiliary solvent can improve the solubility of the nano-color paste in the aqueous solvent, and the water-soluble solvents of alcohol and ether can adjust the viscosity and surface tension of the ink, improving the moisture retention and fluidity of the ink. Secondly, the use of auxiliary solvents with lower boiling points can accelerate the sublimation and volatilization of the solvent during the transfer and drying process of the ink, accelerate the drying speed of the ink, and improve the quick-drying property of the ink.

[0039] Optionally, the wetting agent is a mixture of AFCONA 3522, METOLAT 355 and TERIC 324, and the mixing weight ratio of the AFCONA 3522, the METOLAT 355 and the TERIC 324 is (4-6): (4-8): 1.

[0040] By adopting the above technical solution, the three wetting agents of organic modified polysiloxane, polyamide wax-polyethylene oxide condensate and non-ionic surfactant have different wetting mechanisms. When they are mixed in a ratio of (4-6): (4-8): 1, a certain synergistic effect is produced, thereby improving the overall fluidity of the thermal sublimation ink, which is beneficial to improving the fluency and stability of the thermal sublimation ink during high-speed printing.

[0041] Optionally, the emulsifying thickener is a mixture of polyvinyl pyrrolidone and a polyurethane thickener, wherein the mixing ratio is 1:(1.5-2).

[0042] By adopting the above technical scheme, a certain synergistic effect is produced between polyvinyl pyrrolidone and the polyurethane thickener, so that the prepared thermal sublimation ink has good viscosity and quick drying properties, which is beneficial to prevent the ink from smudging and diffusing due to too long drying time during transfer, thereby improving the sharpness of printing and reducing the granularity, thereby improving the transfer effect.

[0043] Optionally, the pH regulator II is any one of ammonia water, triethylamine, disodium EDTA or tetrasodium EDTA.

[0044] By adopting the above technical solution, the pH value of the thermal sublimation ink can be adjusted and stabilized, which is beneficial to improving the stability and applicability of the thermal sublimation ink.

[0045] Optionally, the bactericidal preservative is a mixture of bactericide MBT-25 and preservative K26, and the mixing weight ratio of the bactericide MBT-25 to the preservative K26 is 1:(1.2-1.5).

[0046] By adopting the above technical solution, the bactericide MBT-25 and the preservative K26 are mixed in a weight ratio of 1: (1.2-1.5). The two additives cooperate with each other to effectively reduce and inhibit the reproduction of various algae and bacteria, which is beneficial to improve the storage stability of the thermal sublimation ink and extend the storage time of the thermal sublimation ink, so that the thermal sublimation ink can still maintain good printing fluency and printing stability after being placed for a long time.

[0047] In the second aspect, the present application provides a method for preparing a water-based digital printing sublimation ink using the following technical solution:

[0048] A method for preparing a water-based digital printing sublimation ink comprises the following steps:

[0049] S1. First, mix the aqueous solvent, the bactericidal preservative and the pH adjuster, and continue stirring at a stirring speed of 400-800 r / min for 20-30 min to obtain a first base material;

[0050] S2, slowly adding a wetting agent to the solvent base material prepared in step S1, and stirring continuously at a stirring speed of 400-800 r / min for 20-30 min until the overall solution is clear, and then slowly adding an emulsifying thickener, and stirring again at a stirring speed of 400-800 r / min for 20-30 min until the overall solution is clear, to obtain a second base material;

[0051] S3, adding nano color paste to the second base material prepared in step S2, stirring at a stirring speed of 400-800 r / min for 20-30 min to obtain a preliminary ink material;

[0052] S4, stacking multiple layers of micron hydrophilic filter membranes with different pore sizes, and performing vacuum filtration on the ink raw material prepared in step S3 to obtain thermal sublimation ink.

[0053] By adopting the above technical solution, the wetting agent, emulsified thickener and nano-color paste are added separately in different steps, which is conducive to making the wetting agent, emulsified thickener and nano-color paste fully miscible and evenly dispersed with the aqueous solvent. Secondly, using multiple layers of micron hydrophilic filter membranes with different pore sizes for superimposed filtration is conducive to improving the filtration effect of the ink, making the thermal sublimation ink more delicate, and improving the fluidity of the thermal sublimation ink to prevent clogging of the printer nozzle.

[0054] In summary, the technical solution of the present application has at least one of the following beneficial effects:

[0055] 1. By using wetting agents to adjust the viscosity and surface tension of thermal sublimation inks and control the water-oil balance in the ink, it is beneficial to improve the fluidity and stability of thermal sublimation inks, making it less likely for thermal sublimation inks to clog the nozzles during high-speed printing, reducing the occurrence of broken holes during printing, and further reducing the broken hole rate during printing.

[0056] 2. By using emulsifying thickener to thicken and dissolve the ink, it is beneficial to make the nano-color paste fully dissolved in the aqueous solvent and evenly dispersed, which not only makes the ink evenly colored, but also helps to improve the quick-drying property of the ink, so that the thermal sublimation ink can dry quickly after transfer, and prevent the ink from smudging during the transfer and drying process, thereby improving the sharpness of the print, reducing the granularity, and improving the transfer effect.

[0057] 3. By using sodium carboxymethyl lignin sulfonate as a dispersant for nano-color paste, it is beneficial to keep the thermal sublimation ink stable during the transfer and drying process, which is not only beneficial for the thermal sublimation ink to have uniform color after drying, but also beneficial for improving the sharpness of the pattern. DETAILED DESCRIPTION

[0058] The present application is further described in detail below in combination with preparation examples, embodiments and comparative examples.

[0059] Preparation Example

[0060] [Preparation Example 1-1]

[0061] A lignin dispersant comprises the following preparation steps:

[0062] A1. 10 kg of lignin, 4% sodium hydroxide solution and deionized water were prepared into a mixed solution with a lignin mass fraction of 28% and a pH value of 13, and then 3 kg of a mixed solution of sodium sulfite and formaldehyde was added, wherein the molar ratio of sodium sulfite to formaldehyde was 3:1, and then the temperature was raised to 160°C for reaction for 5 hours to obtain sulfomethylated lignin.

[0063] [Preparation Example 1-2]

[0064] A lignin dispersant comprises the following preparation steps:

[0065] B1. 15 kg of lignin, 4% sodium hydroxide solution and deionized water were prepared into a mixed solution with a lignin mass fraction of 25% and a pH value of 10, and then 6 kg of a mixed solution of sodium sulfite and formaldehyde was added, wherein the molar ratio of sodium sulfite to formaldehyde was 3.5:1, and then the temperature was raised to 200 ° C in a sealed state for reaction for 4 hours to obtain sulfomethylated lignin;

[0066] B2, take 10kg of the sulfomethylated lignin obtained in step B1 and transfer it to a normal pressure reactor, use a 4% sodium hydroxide solution and deionized water to adjust it to a mixed solution with an effective ingredient of 30% and a pH value of 11.5, then raise the temperature to 70°C, slowly add 2.5kg of chloroacetic acid within 60min, and after the addition is completed, continue to maintain the temperature for 120min to obtain sodium carboxymethylated lignin sulfonate.

[0067] [Preparation Example 2-1]

[0068] A black nano-color paste comprising the following raw materials:

[0069] 48kg of deionized water, 12kg of dispersed color powder, 8kg of lignin dispersant, 2.5kg of co-dispersant, 14kg of humectant, 0.15kg of defoamer, 0.1kg of pH adjuster, and 0.2kg of bactericide.

[0070] The dispersed color powder is a black dispersed color powder prepared by mixing CI Disperse Violet 27, CI Disperse Orange 37 and CI Disperse Blue 26 in a ratio of 0.5:1.85:0.65.

[0071] Among them, the lignin dispersant is the sulfomethylated lignin prepared in [Preparation Example 1-1], the dispersant is OP-10, the moisturizer is a mixture of 1,2-propylene glycol and sorbitol in a ratio of 2:1.2, the defoamer is KMT-2038 from Kemet, the pH adjuster is disodium EDTA, and the bactericide is MBT-25.

[0072] A black nano-color paste comprises the following preparation steps:

[0073] C1. First, half of the weight of deionized water and the moisturizer are fully stirred, and then the dispersant, the co-dispersant, the defoamer, the bactericide and the pH adjuster I are added and stirred again, and the stirring is continued for 20 minutes to obtain the master batch A; then the other half of the weight of deionized water and the dispersed color powder are stirred and mixed, and the stirring is continued for 20 minutes to obtain the master batch B;

[0074] C2, continuously stirring the masterbatch A prepared in step C1, and then slowly adding the masterbatch B during the stirring process to fully mix the masterbatch A and the masterbatch B to form a uniformly dispersed mixed solution, and then stirring and dispersing the mixed solution at a high speed for 120 minutes to obtain a pre-treated solution;

[0075] C3. The pretreatment liquid obtained in step C2 is subjected to multiple cycles of grinding, wherein the size of the zirconium beads is selected to be 0.20 mm, and the grinding speed is 3000 rpm, until the average particle size of the material is D50≤120 nm and D90≤250 nm, thereby obtaining a nano color paste.

[0076] [Preparation Example 2-2]

[0077] A black nano-color paste, which differs from [Preparation Example 2-1] in that the lignin dispersant is different.

[0078] In this preparation example, the lignin dispersant is the carboxymethylated sodium lignin sulfonate prepared in [Preparation Example 1-2].

[0079] [Preparation Example 2-3]

[0080] A yellow nano-color paste, which differs from [Preparation Example 2-2] in that the lignin dispersant is replaced by a naphthalenesulfonate dispersant in equal amounts.

[0081] In this preparation example, the naphthalenesulfonate dispersant is NNO dispersant.

[0082] [Preparation Example 2-4]

[0083] A blue nano-color paste, which differs from [Preparation Example 2-2] in that the dispersed color powder is different.

[0084] In this preparation example, CI Disperse Blue 60 was selected as the dispersed toner.

[0085] [Preparation Example 2-5]

[0086] A red nano-color paste, which differs from [Preparation Example 2-2] in that the dispersed color powder is different.

[0087] In this preparation example, CI Disperse Red 65 was selected as the dispersed toner.

[0088] [Preparation Example 2-6]

[0089] A yellow nano-color paste, which differs from [Preparation Example 2-2] in that the dispersed color powder is different.

[0090] In this preparation example, CI Disperse Yellow 64 was selected as the dispersed toner. Example

[0091] [Example 1]

[0092] A thermal sublimation ink, comprising the following raw materials:

[0093] 75kg aqueous solvent, 12kg nano color paste, 1.6kg wetting agent, 8kg emulsifying thickener, 0.6kg pH adjuster II, 0.5kg bactericidal preservative.

[0094] The aqueous solvent includes deionized water and an auxiliary solvent. Specifically, the amount of the auxiliary solvent added is 40 kg. The auxiliary solvent is selected from 1,2-propylene glycol, glycerol and 1,5-pentanediol mixed in a weight ratio of 1:5:2.

[0095] Among them, the nano-color paste is a black nano-color paste prepared in [Preparation Example 2-1]; the wetting agent is AFCONA3522 and TERIC 324 mixed in a ratio of 4:1; the emulsifying thickener is a polyvinyl pyrrolidone thickener, specifically PVP-K30; the pH adjuster II is selected at a concentration of disodium EDTA, and the bactericidal preservative is a bactericide MBT-25 and a preservative K26 mixed in a weight ratio of 1:1.5.

[0096] A thermal sublimation ink comprises the following preparation steps:

[0097] S1. First, mix the aqueous solvent, the bactericidal preservative and the pH adjuster, and stir them at a stirring speed of 500 r / min for 20 min to obtain a first base material;

[0098] S2, slowly adding a wetting agent to the first base material prepared in step S1, and stirring at a stirring speed of 500 r / min for 20 min until the solution is clear as a whole, and then slowly adding an emulsifying thickener, and stirring at a stirring speed of 500 r / min for another 20 min until the solution is clear as a whole, to obtain a second base material;

[0099] S3, adding nano color paste to the second base material prepared in step S2, stirring at a stirring speed of 500 r / min for 30 minutes to obtain a preliminary ink material;

[0100] S4, a hydrophilic filter membrane with a pore size of 0.22 μm and a hydrophilic filter membrane with a pore size of 0.45 μm are stacked on each other, and the ink raw material prepared in step S3 is filtered under reduced pressure to obtain thermal sublimation ink.

[0101] [Example 2]

[0102] A thermal sublimation ink, comprising the following raw materials:

[0103] 60kg aqueous solvent, 25kg nano color paste, 2.4kg wetting agent, 4kg emulsifying thickener, 0.4kg pH adjuster II, 1kg bactericidal preservative.

[0104] Wherein, the aqueous solvent includes deionized water and an auxiliary solvent, specifically, the amount of the auxiliary solvent added is 20 kg, and the auxiliary solvent is Liponic EG-1; the nano-color paste is a black nano-color paste prepared in [Preparation Example 2-1]; the wetting agent is AFCONA 3580 and METOLAT 362 mixed in a ratio of 1:1.2; the emulsifying thickener is a mixture of a polyvinyl pyrrolidone thickener and a polyurethane thickener, specifically PVP-K20 and TEGO Viscoplus 3010 are mixed in a weight ratio of 1:2; the pH adjuster II is triethanolamine in concentration, and the bactericidal preservative is a bactericide MBT-25 and a preservative K26 mixed in a weight ratio of 1:1.2.

[0105] A thermal sublimation ink comprises the following preparation steps:

[0106] S1. First, mix the aqueous solvent, the bactericidal preservative and the pH adjuster, and stir them at a stirring speed of 400 r / min for 30 min to obtain a first base material;

[0107] S2, slowly adding a wetting agent to the first base material prepared in step S1, and stirring at a stirring speed of 400 r / min for 30 min until the solution is clear as a whole, and then slowly adding an emulsifying thickener, and stirring at a stirring speed of 400 r / min for another 30 min until the solution is clear as a whole, to obtain a second base material;

[0108] S3, adding nano color paste to the second base material prepared in step S2, stirring at a stirring speed of 400 r / min for 30 minutes to obtain a preliminary ink material;

[0109] S4, a hydrophilic filter membrane with a pore size of 0.22 μm and a hydrophilic filter membrane with a pore size of 0.45 μm are stacked on each other, and the ink raw material prepared in step S3 is filtered under reduced pressure to obtain thermal sublimation ink.

[0110] [Example 3]

[0111] A thermal sublimation ink, comprising the following raw materials:

[0112] 80kg of aqueous solvent, 10kg of nano color paste, 1kg of wetting agent, 10kg of emulsifying thickener, 1kg of pH adjuster II, and 0.8kg of bactericidal preservative.

[0113] The aqueous solvent includes deionized water and an auxiliary solvent. Specifically, the auxiliary solvent is added in an amount of 30 kg, and diethylene glycol monobutyl ether is selected as the auxiliary solvent; the nano-color paste is a black nano-color paste prepared in [Preparation Example 2-1]; the wetting agent is AFCONA 3585, METOLAT 365 and TERIC 168 mixed in a ratio of 1:4:1; the emulsifying thickener is a polyurethane thickener, specifically TEGO Viscoplus 3030; the pH adjuster II is selected in a concentration of tetrasodium EDTA, and the bactericide and preservative are selected by mixing bactericide MBT-25 and preservative K26 in a weight ratio of 1:1.5.

[0114] A thermal sublimation ink comprises the following preparation steps:

[0115] S1, firstly mix the aqueous solvent, the bactericidal preservative and the pH adjuster, and continuously stir at a stirring speed of 800 r / min for 30 min to obtain a first base material;

[0116] S2, slowly adding a wetting agent to the first base material prepared in step S1, and stirring at a stirring speed of 800 r / min for 30 min until the solution is clear as a whole, and then slowly adding an emulsifying thickener, and stirring at a stirring speed of 800 r / min for another 30 min until the solution is clear as a whole, to obtain a second base material;

[0117] S3, adding nano color paste to the second base material prepared in step S2, stirring at a stirring speed of 800 r / min for 30 min to obtain a preliminary ink material;

[0118] S4, a hydrophilic filter membrane with a pore size of 0.22 μm and a hydrophilic filter membrane with a pore size of 0.45 μm are stacked on each other, and the ink raw material prepared in step S3 is filtered under reduced pressure to obtain thermal sublimation ink.

[0119] [Example 4]

[0120] A thermal sublimation ink, which is different from [Example 1] in that the nano color paste is different.

[0121] In this embodiment, the nano-color paste is a black nano-color paste prepared in [Preparation Example 2-2].

[0122] [Example 5]

[0123] An ink, which is different from [Example 1] in that the nano color paste is different.

[0124] In this embodiment, the nano-color paste is a black nano-color paste prepared in [Preparation Example 2-3].

[0125] [Example 6]

[0126] A thermal sublimation ink, which is different from [Example 4] in that the wetting agent is different.

[0127] In this embodiment, the wetting agent is a mixture of METOLAT 355 and TERIC 324 in a ratio of 8:1.

[0128] [Example 7]

[0129] A thermal sublimation ink, which is different from [Example 4] in that the wetting agent is different.

[0130] In this embodiment, the wetting agent is AFCONA 3522, METOLAT 355 and TERIC 324 mixed in a ratio of 4:8:1.

[0131] [Example 8]

[0132] A thermal sublimation ink, which is different from [Example 7] in that the emulsifying thickener is different.

[0133] In this embodiment, the emulsifying thickener is a mixture of a polyvinyl pyrrolidone thickener and a polyurethane thickener, specifically, PVP-K30 and TEGO Viscoplus 3010 are mixed in a weight ratio of 1:1.5.

[0134] [Example 9]

[0135] A thermal sublimation ink, which is different from [Example 8] in that the nano color paste is different.

[0136] In this embodiment, the nano-color paste is a blue nano-color paste prepared in [Preparation Example 2-4].

[0137] [Example 10]

[0138] A thermal sublimation ink, which is different from [Example 8] in that the nano color paste is different.

[0139] In this embodiment, the nano-color paste is a red nano-color paste prepared in [Preparation Example 2-5].

[0140] [Example 11]

[0141] A thermal sublimation ink, which is different from [Example 8] in that the nano color paste is different.

[0142] In this embodiment, the nano-color paste is a yellow nano-color paste prepared in [Preparation Example 2-6]. Comparative Example

[0143] [Comparative Example 1]

[0144] An ink, purchased from a domestic brand T673 series CMYK digital printing ink, the color is BK black.

[0145] [Comparative Example 2]

[0146] An ink, purchased from a domestic brand T673 series CMYK digital printing ink, the color is C cyan.

[0147] [Comparative Example 3]

[0148] An ink, purchased from a domestic brand T673 series CMYK digital printing ink, the color is M magenta.

[0149] [Comparative Example 4]

[0150] An ink, purchased from a domestic brand T673 series CMYK digital printing ink, the color is Y yellow.

[0151] Performance test data

[0152] The inks prepared in Examples 1-10 and Comparative Examples 1-2 were applied to an inkjet printer, and EPSON 5113 nozzles were used to print solid color block patterns on thermal transfer paper. After printing, the patterns were thermally transferred to satin cloth at 225° C. within 30 seconds using a heat press, and then dried at a medium to low temperature of 120° C.

[0153] 1. Fluency: EPSON 5113 printhead was used to continuously print 20 m2 at a speed of 30-40 m2 / H, and the broken hole rate of each embodiment and comparative example was measured and recorded.

[0154] 2. Stability: EPSON 5113 printhead was used to continuously print 100 m2 at a speed of 30-40 m2 / H, and the broken hole rate and trend of each embodiment and comparative example were measured and recorded.

[0155] 3. Quick drying: During the drying process at medium and low temperatures, use the same thermal transfer paper to print and test for obvious discoloration at 1min, 2min, 3min, 4min, and 5min. Record the time period without discoloration. It can be judged that it has been completely dried and cured before this time period.

[0156] 4. Sharpness: EPSON 5113 printhead is used to print on special inkjet thermal transfer paper, and 26 English New Roman characters of 4P, 6P, 8P, 10P, and 12P sizes are printed respectively, recording the smallest clearly visible handwriting.

[0157] Table 1 Ink performance test data

[0158]

[0159] Combining Example 1 with Comparative Example 1 and the data in Table 1, it can be seen that by using a wetting agent formed by mixing an organically modified polysiloxane and a non-ionic surfactant, and fully mixing the homemade nano-color paste with a polyvinyl pyrrolidone thickener, the obtained thermal sublimation ink has better fluidity and stability than the existing thermal sublimation ink, and the quick-drying property and sharpness are also significantly improved.

[0160] Combining Example 1 with Example 4-5 and the data in Table 1, it can be seen that the use of lignin dispersant in the homemade nano-color paste is significantly improved in terms of fluency and sharpness compared to the use of naphthalenesulfonate dispersants to obtain thermal sublimation ink. This may be because the heat resistance of naphthalenesulfonate dispersants is relatively low. In the production process, high-temperature transfer and medium-low temperature drying are required. During the transfer and drying process, naphthalenesulfonate dispersants are easily decomposed by heat, which may affect the printing and transfer effects of the ink. Secondly, the stability of the thermal sublimation ink obtained by the nano-color paste using carboxymethylated sodium lignin sulfonate as a dispersant is further improved. This may be because carboxymethylated sodium lignin sulfonate has good high-temperature stability, can remain stable during transfer and drying, and carboxymethylation can reduce the phenolic hydroxyl content on the surface of lignin, further reducing the reduction rate of the dispersed color powder, which is not only conducive to fully coloring the dispersed color powder, but also conducive to improving the sharpness of pattern printing.

[0161] Combining Example 4 with Example 6-7 and the data in Table 1, it can be seen that when the lubricant is selected from a mixture of organically modified polysiloxane, polyamide wax-polyethylene oxide condensate and non-ionic surfactant, specifically, AFCONA3522, METOLAT 355 and TERIC 324 are mixed in a weight ratio of 4:8:1, the obtained thermal sublimation ink has better stability. This may be because the three wetting agents of organically modified polysiloxane, polyamide wax-polyethylene oxide condensate and non-ionic surfactant have different wetting mechanisms, and mixing them in a certain proportion may produce a certain synergistic effect, thereby further improving the overall flow properties of the obtained thermal sublimation ink.

[0162] Combining Examples 7-8 and the data in Table 1, it can be seen that when the emulsifying thickener is a mixture of polyvinyl pyrrolidone and a polyurethane thickener, specifically, PVP-K30 and TEGO Viscoplus 3010 are mixed at a weight ratio of 1:1.5, the obtained thermal sublimation ink has good viscosity and quick drying, and the drying speed can reach ≤1min. This is conducive to preventing the ink from smudging and diffusing due to too long drying time during transfer, thereby improving the sharpness of printing, reducing the graininess, and improving the transfer effect.

[0163] This specific implementation manner is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the specific implementation manner as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A water-based digital printing sublimation ink, characterized in that: It includes the following raw materials in parts by weight: Aqueous solvent: 60-80 parts; Nano color paste: 5-30 parts; Wetting agent: 0.1-3 parts; Emulsifying thickener: 1-10 parts; pH regulator II: 0.1-1 part; Bactericidal preservative: 0.1-1 part; The aqueous solvent comprises deionized water and an auxiliary solvent, the mixing ratio of the deionized water to the auxiliary solvent is 1:(0.2-1.3), the auxiliary solvent is 1,2-propylene glycol, glycerol and 1,5-pentanediol mixed in a weight ratio of 1:5:2; the wetting agent is AFCONA 3522, METOLAT 355 and TERIC 324 mixed in a weight ratio of (4-6):(4-8):1; the emulsifying thickener is polyvinyl pyrrolidone and a polyurethane thickener mixed in a weight ratio of 1:(1.5-2); Wherein, the nano color paste comprises the following raw materials in parts by weight: Deionized water: 20-50 parts; Dispersed color powder: 10-20 parts; Dispersant: 5-10 parts; Dispersant: 1-3 parts; Moisturizer: 10-20 parts; Defoaming agent: 0.1-0.3 parts; pH regulator I: 0.1-0.3 parts; Fungicide: 0.1-0.3 parts; The dispersant is carboxymethylated sodium lignin sulfonate.

2. The water-based digital printing sublimation ink according to claim 1, characterized in that: The carboxymethylated sodium lignin sulfonate comprises the following preparation steps: B1. A certain amount of lignin, alkaline solution and deionized water are prepared into a mixed solution with a lignin mass fraction of 25%-30% and a pH value of 10-12, and then a certain amount of sodium sulfite and formaldehyde are added, and the temperature is raised to 160-200° C. in a sealed state to react for 4-5 hours to obtain sulfomethylated sodium lignin sulfonate; B2, using alkaline solution and deionized water to adjust the sulfomethylated sodium lignin sulfonate obtained in step B1 into a mixed solution with an effective ingredient of 25%-30% of sulfomethylated sodium lignin sulfonate and a pH value of 10.5-13.5, then raising the temperature to 60-80° C., slowly adding a certain amount of chloroacetic acid dropwise within a certain period of time, and after the addition is completed, continuing to maintain the temperature for 90-120 min to obtain carboxymethylated sodium lignin sulfonate.

3. The water-based digital printing sublimation ink according to claim 1, characterized in that: The nano color paste comprises the following preparation steps: C1. First, half of the weight of deionized water and the moisturizer are fully stirred, and then the dispersant, the co-dispersant, the defoamer, the bactericide and the pH adjuster I are added and stirred again to obtain a master batch A; then the other half of the weight of the deionized water and the dispersed color powder are stirred and mixed to obtain a master batch B; C2, continuously stirring the masterbatch A prepared in step C1, and then slowly adding the masterbatch B during the stirring process to fully mix the masterbatch A and the masterbatch B to form a uniformly dispersed mixed solution, and then stirring and dispersing the mixed solution at a high speed for 120-150 minutes to obtain a pre-treated solution; C3. Grind the pretreatment liquid obtained in step C2 for multiple cycles until the average particle size of the material is D50≤120nm and D90≤250nm, thereby obtaining a nano color paste.

4. The water-based digital printing sublimation ink according to claim 1, characterized in that: The pH regulator II is selected from any one of ammonia water, triethylamine, disodium EDTA or tetrasodium EDTA.

5. The water-based digital printing sublimation ink according to claim 1, characterized in that: The bactericidal preservative is a mixture of bactericide MBT-25 and preservative K26, and the mixing weight ratio of the bactericide MBT-25 to the preservative K26 is 1: (1.2-1.5).

6. A method for preparing a water-based digital printing sublimation ink according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. First, mix the aqueous solvent, the bactericidal preservative and the pH regulator II, and continue stirring at a stirring speed of 400-800 r / min for 20-30 min to obtain a first base material; S2, slowly adding a wetting agent to the solvent base material prepared in step S1, and stirring continuously at a stirring speed of 400-800 r / min for 20-30 min until the overall solution is clear, and then slowly adding an emulsifying thickener, and stirring again at a stirring speed of 400-800 r / min for 20-30 min until the overall solution is clear, to obtain a second base material; S3, adding nano color paste to the second base material prepared in step S2, stirring at a stirring speed of 400-800 r / min for 20-30 min to obtain a preliminary ink material; S4, stacking multiple layers of micron hydrophilic filter membranes with different pore sizes, and performing vacuum filtration on the ink raw material prepared in step S3 to obtain thermal sublimation ink.

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