High-moisture-retention water-based paint ink as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of coating ink-jet ink, and discloses high-moisture-retention water-based coating ink as well as a preparation method and application thereof. The high-moisture-retention water-based paint ink is prepared from the following components in parts by mass: 5 to 20 parts of a water-based solvent, 15 to 30 parts of resin, 20 to 40 parts of color paste, 5 to 20 parts of a low-viscosity humectant, 0.1 to 1 part of a surfactant and 5 to 50 parts of water. The low-viscosity humectant provided by the invention is good in performance, has water solubility and moisture retention, and can reduce the moisture volatilization speed in the printing process, protect a spray head from being wet and not dry up and prevent the spray head from being blocked. The viscosity of the ink system can be adjusted while the moisture retention is improved, ink droplets can be sprayed out uniformly due to the proper viscosity, and the color intensity and uniformity are improved. The prepared ink is bright in color and smooth in ink jet, and can be stably stored for a long time.

Description

Technical Field

[0001] This invention relates to the field of inkjet coating technology, and in particular to a high-moisture water-based coating ink, its preparation method, and its application. Background Technology

[0002] Digital textile printing, characterized by its lack of plate-making requirements and simple process, enables small-batch, multi-variety, multi-color, and personalized customization, allowing for rapid response to market changes. It has gradually replaced traditional printing technologies and become the mainstream printing solution. Meanwhile, pigment inks, due to their wide adaptability, environmentally friendly production process with no wastewater discharge, reduce enterprise production costs and simplify production processes, gradually becoming the mainstream. With the growth of industry demand, processes such as wide-format printing and single-pass printing have emerged, and the long-term, high-intensity printing places higher demands on the moisture retention of pigment inks.

[0003] The moisturizing property of ink mainly refers to the time that the ink remains moist during and after printing. This prevents the ink from drying out or clogging the printhead due to rapid evaporation, and directly determines the ink's performance. The moisturizing property of ink is related to the moisturizing ability and concentration of the humectant. Low humectant ability or concentration leads to faster drying, and with prolonged use, the ink dries and condenses at the printhead, easily causing clogging. Low-concentration humectants can also result in excessively low ink viscosity, causing satellite droplets to form during printing, which also affects print quality.

[0004] Patent CN118931260A discloses an inkjet printing ink and its preparation method. The ink comprises 55-65% pigment, 2-3.5% humectant, 0.8-1% polyethylene glycol, and 1-1.5% polyvinylpyrrolidone, and has moisturizing properties. However, its pigment contains 1-1.5% sodium fluoride, which may cause discomfort with prolonged contact.

[0005] The usual method to improve humectability is to increase the amount of humectant used. However, if the concentration of humectant is too high, it will lead to increased viscosity. During high-intensity printing, excessively high ink viscosity can cause the ink path to not supply ink smoothly, which may result in broken lines in the print. Excessively high viscosity will also cause the ejected ink droplets to become smaller, making the printed color lighter.

[0006] Therefore, it is of great significance to study and obtain a high-moisture water-based coating ink that can meet the requirements of long-term, high-intensity printing, as well as its preparation method and application. Summary of the Invention

[0007] The purpose of this invention is to provide a high-moisture water-based coating ink, its preparation method and application, thereby solving the problem of poor moisture retention in existing coating inks.

[0008] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a high-moisturizing water-based coating ink, comprising the following components in parts by weight: 5-20 parts aqueous solvent, 15-30 parts resin, 20-40 parts color paste, 5-20 parts low viscosity moisturizer, 0.1-1 part surfactant and 5-50 parts water; The structural formula of the low-viscosity moisturizer is:

[0009] Where n is any integer from 1 to 6; R4 is O, S, or NH; R1, R2, or R3 are independently H, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 alkenyl, or C1-C6 alkynyl.

[0010] Preferably, the aqueous solvent includes one or more of ethanol, n-propanol, isopropanol, n-butanol, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, polyethylene glycol 200, polyethylene glycol 400, polyethylene glycol 600, diethylene glycol, triethylene glycol, glycerol, pentaerythritol, 2-pyrrolidone, and N-methylpyrrolidone.

[0011] Preferably, the resin includes one or more of polyurethane resin, acrylic resin, polyolefin resin, epoxy resin, formaldehyde resin, urea-formaldehyde resin, and fluorocarbon resin.

[0012] Preferably, the color paste includes nano-pigment color paste.

[0013] Preferably, the surfactant includes one or more of acetylenic diols, polyether siloxanes, acrylics, and organofluorine compounds.

[0014] The present invention also provides a method for preparing a high moisturizing water-based coating ink, wherein the preparation steps of the method are as follows: mixing an aqueous solvent, resin, color paste, low viscosity moisturizing agent, surfactant and water to obtain an aqueous coating ink.

[0015] Preferably, the mixing is carried out under stirring, with a stirring speed of 200~500 rpm and a stirring time of 0.5~5 h.

[0016] This invention also provides the application of the aforementioned high-moisture water-based coating ink in the field of digital textile printing.

[0017] As can be seen from the above technical solution, compared with the prior art, the present invention has the following beneficial effects: This invention provides a high-performance, low-viscosity moisturizing agent that is water-soluble and moisturizing. It reduces the rate of moisture evaporation during printing, keeping the printhead moist and preventing clogging. While improving moisturizing properties, it also adjusts the viscosity of the ink system; a suitable viscosity allows for uniform ink droplet ejection, improving color intensity and uniformity. The prepared ink exhibits vibrant colors, smooth inkjet flow, and long-term stable storage. Detailed Implementation

[0018] This invention provides a high-moisturizing water-based coating ink, comprising the following components in parts by weight: 5-20 parts aqueous solvent, 15-30 parts resin, 20-40 parts color paste, 5-20 parts low viscosity moisturizer, 0.1-1 part surfactant and 5-50 parts water; The structural formula of the low-viscosity moisturizer is:

[0019] Where n is any integer from 1 to 6; R4 is O, S, or NH; R1, R2, or R3 are independently H, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 alkenyl, or C1-C6 alkynyl.

[0020] In this invention, the aqueous solvent is preferably 6-15 parts by mass, more preferably 7-12 parts, and even more preferably 8-10 parts by mass; the resin is preferably 18-28 parts by mass, more preferably 20-25 parts, and even more preferably 21-24 parts by mass; the color paste is preferably 25-35 parts by mass, more preferably 26-32 parts, and even more preferably 28-30 parts by mass; the low-viscosity humectant is preferably 6-18 parts by mass, more preferably 8-15 parts, and even more preferably 10-12 parts by mass; the surfactant is preferably 0.2-0.8 parts by mass, more preferably 0.4-0.7 parts, and even more preferably 0.5-0.6 parts by mass; and the water is preferably 10-40 parts by mass, more preferably 20-35 parts, and even more preferably 25-30 parts by mass.

[0021] In this invention, the aqueous solvent preferably includes one or more of the following: ethanol, n-propanol, isopropanol, n-butanol, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, polyethylene glycol 200, polyethylene glycol 400, polyethylene glycol 600, diethylene glycol, triethylene glycol, glycerol, pentaerythritol, 2-pyrrolidone, and N-methylpyrrolidone.

[0022] In this invention, the resin preferably includes one or more of polyurethane resin, acrylic resin, polyolefin resin, epoxy resin, formaldehyde resin, urea-formaldehyde resin and fluorocarbon resin.

[0023] In this invention, the color paste preferably includes a nano pigment color paste, and the D50 of the nano pigment color paste is preferably 100~130nm, further having 105~125nm within impurities, and more preferably 110~120nm.

[0024] In this invention, the surfactant preferably includes one or more of the following: acetylenic diols, polyether siloxanes, acrylics, and organofluorine compounds.

[0025] The present invention also provides a method for preparing a high moisturizing water-based coating ink, wherein the preparation steps of the method are as follows: mixing an aqueous solvent, resin, color paste, low viscosity moisturizing agent, surfactant and water to obtain an aqueous coating ink.

[0026] In this invention, the mixing is preferably carried out under stirring, the stirring speed is preferably 200~500 rpm, more preferably 250~450 rpm, more preferably 300~400 rpm, and the stirring time is preferably 0.5~5h, more preferably 1~4h, and more preferably 2~3h.

[0027] In this invention, the mixture is filtered, and the filtration is preferably membrane filtration. The membrane is preferably a PP filter membrane, and the pore size of the PP filter membrane is preferably 0.4~0.5μm, more preferably 0.42~0.48μm, and even more preferably 0.45~0.46μm.

[0028] This invention also provides the application of the aforementioned high-moisture water-based coating ink in the field of digital textile printing.

[0029] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0030] In this embodiment of the invention, the resin was purchased from Mitsui Chemicals, Japan, model W-6110; the surfactant was purchased from Evonik Specialty Chemicals, model Surfynol 465.

[0031] Example 1

[0032] 74.08 g of methylurea was dissolved in 200 mL of ethylene glycol at 50 °C. Then, 60.10 g of ethylenediamine and 35 g of 25% ammonia solution were added, and the mixture was heated to 200 °C and maintained at this temperature for 4 hours. After the reaction was complete, the mixture was cooled to 30 °C and centrifuged to obtain crude N-methyl-2-imidazolium ketone. After rinsing with ethanol and drying, the low-viscosity humectant N-methyl-2-imidazolium ketone was obtained, with the following structural formula: .

[0033] 10 parts glycerol, 30 parts W-6110, 30 parts nano pigment paste (D50 of 120nm), 13 parts N-methyl-2-imidazolidineone, 1 part surfynol 465 and 16 parts water were mixed and stirred at 300 rpm for 2 hours. After stirring, the mixture was filtered through a PP filter membrane with a pore size of 0.45μm to obtain a high-moisture water-based coating ink.

[0034] Example 2

[0035] 88.11 g of dimethylurea was dissolved in 200 mL of ethylene glycol at 50 °C. Then, 60.10 g of ethylenediamine and 35 g of 25% ammonia solution were added, and the mixture was heated to 200 °C and maintained at this temperature for 4 hours. After the reaction was complete, the mixture was cooled to 30 °C and centrifuged to obtain crude N,N-dimethyl-2-imidazolium ketone. After rinsing with ethanol and drying, the low-viscosity humectant N,N-dimethyl-2-imidazolium ketone was obtained, with the following structural formula: .

[0036] 10 parts glycerol, 30 parts W-6110, 30 parts nano pigment paste (D50 of 120nm), 13 parts N,N-dimethyl-2-imidazolidineone, 1 part surfynol 465 and 16 parts water were mixed and stirred at 300 rpm for 2 hours. After stirring, the mixture was filtered through a PP filter membrane with a pore size of 0.45μm to obtain a high-moisture water-based coating ink.

[0037] Example 3

[0038] 74.08 g of methylurea was dissolved in 200 mL of ethylene glycol at 50 °C. Then, 74.16 g of 1,2-propanediamine and 35 g of 25% ammonia solution were added, and the mixture was heated to 200 °C and maintained at this temperature for 4 hours. After the reaction was complete, the mixture was cooled to 30 °C and centrifuged to obtain crude 1,4-dimethyl-2-imidazolidineone. After rinsing with ethanol and drying, a low-viscosity humectant, 1,4-dimethyl-2-imidazolidineone, was obtained, with the following structural formula: .

[0039] Eight parts of glycerol, 30 parts of W-6110, 30 parts of nano pigment paste (D50 of 120nm), 15 parts of 1,4-dimethyl-2-imidazolidineone, 1 part of Surfynol 465, and 16 parts of water were mixed and stirred at 300 rpm for 2 hours. After stirring, the mixture was filtered through a PP membrane with a pore size of 0.45 μm to obtain a high-moisture water-based coating ink.

[0040] Example 4

[0041] 88.11 g of dimethylurea was dissolved in 200 mL of ethylene glycol at 50 °C. Then, 74.16 g of 1,2-propanediamine and 35 g of 25% ammonia solution were added, and the mixture was heated to 200 °C and maintained at this temperature for 4 hours. After the reaction was complete, the mixture was cooled to 30 °C and centrifuged to obtain crude 1,3,4-trimethyl-2-imidazolidineone. After rinsing with ethanol and drying, the low-viscosity humectant 1,3,4-trimethyl-2-imidazolidineone was obtained, with the following structural formula: .

[0042] Eight parts of glycerol, 30 parts of W-6110, 30 parts of nano pigment paste (D50 of 120nm), 15 parts of 1,3,4-trimethyl-2-imidazolidineone, 1 part of Surfynol 465 and 16 parts of water were mixed and stirred at 300 rpm for 2 hours. After stirring, the mixture was filtered through a PP filter membrane with a pore size of 0.45μm to obtain a high-moisture water-based coating ink.

[0043] Example 5

[0044] 74.08 g of methylurea was dissolved in 200 mL of ethylene glycol at 50 °C. Then, 74.16 g of 1,3-propanediamine and 35 g of 25% ammonia solution were added, and the mixture was heated to 200 °C and maintained at this temperature for 4 hours. After the reaction was complete, the mixture was cooled to 30 °C and centrifuged to obtain crude N-methylpropenylurea. After rinsing with ethanol and drying, the low-viscosity moisturizing agent N-methylpropenylurea was obtained, with the following structural formula: .

[0045] Six parts of glycerol, 30 parts of W-6110, 30 parts of nano pigment paste (D50 of 120nm), 17 parts of N-methacrylurea, 1 part of surfynol 465 and 16 parts of water were mixed and stirred at 300 rpm for 2 hours. After stirring, the mixture was filtered through a PP filter membrane with a pore size of 0.45μm to obtain a high-moisture water-based coating ink.

[0046] Example 6

[0047] 88.11 g of dimethylurea was dissolved in 200 mL of ethylene glycol at 50 °C. Then, 74.16 g of 1,3-propanediamine and 35 g of 25% ammonia solution were added, and the mixture was heated to 200 °C and maintained at this temperature for 4 hours. After the reaction was complete, the mixture was cooled to 30 °C and centrifuged to obtain crude N,N-dimethylpropenylurea. After rinsing with ethanol and drying, a low-viscosity humectant, N,N-dimethylpropenylurea, was obtained, with the following structural formula: .

[0048] Six parts of glycerol, 30 parts of W-6110, 30 parts of nano pigment paste (D50 of 120nm), 17 parts of N,N-dimethylacrylurea, 1 part of surfynol 465 and 16 parts of water were mixed and stirred at 300 rpm for 2 hours. After stirring, the mixture was filtered through a PP filter membrane with a pore size of 0.45μm to obtain a high-moisture water-based coating ink.

[0049] Example 7

[0050] 76.12 g of thiourea was dissolved in 200 mL of ethylene glycol at 50 °C. Then, 60.10 g of ethylenediamine and 35 g of 25% ammonia solution were added, and the mixture was heated to 200 °C and maintained at this temperature for 4 hours. After the reaction was complete, the mixture was cooled to 30 °C and centrifuged to obtain crude ethylene thiourea. After rinsing with ethanol and drying, a low-viscosity humectant ethylene thiourea was obtained, with the following structural formula: .

[0051] 10 parts glycerol, 30 parts W-6110, 30 parts nano pigment paste (D50 of 120nm), 13 parts ethylene thiourea, 1 part surfynol 465 and 16 parts water were mixed and stirred at 300 rpm for 2 hours. After stirring, the mixture was filtered through a PP filter membrane with a pore size of 0.45μm to obtain a high-moisture water-based coating ink.

[0052] Example 8

[0053] 90.14 g of N-methylthiourea was dissolved in 200 mL of ethylene glycol at 50 °C. Then, 60.10 g of ethylenediamine and 35 g of 25% ammonia solution were added, and the mixture was heated to 200 °C and maintained at this temperature for 4 hours. After the reaction was complete, the mixture was cooled to 30 °C and centrifuged to obtain crude N-methylethylenethiourea. After rinsing with ethanol and drying, a low-viscosity moisturizing agent, N-methylethylenethiourea, was obtained, with the following structural formula: .

[0054] 10 parts glycerol, 30 parts W-6110, 30 parts nano pigment paste (D50 of 120nm), 13 parts N-methylethylene thiourea, 1 part surfynol 465 and 16 parts water were mixed and stirred at 300 rpm for 2 hours. After stirring, the mixture was filtered through a PP filter membrane with a pore size of 0.45μm to obtain a high-moisture water-based coating ink.

[0055] Example 9

[0056] 76.12 g of thiourea was dissolved in 200 mL of ethylene glycol at 50 °C. Then, 74.16 g of 1,2-propanediamine and 35 g of 25% ammonia solution were added, and the mixture was heated to 200 °C and maintained at this temperature for 4 hours. After the reaction was complete, the mixture was cooled to 30 °C and centrifuged to obtain crude 4-methylethylene thiourea. After rinsing with ethanol and drying, the low-viscosity moisturizing agent 4-methylethylene thiourea was obtained, with the following structural formula: .

[0057] Eight parts of glycerol, 30 parts of W-6110, 30 parts of nano pigment paste (D50 of 120nm), 15 parts of 4-methylethylene thiourea, 1 part of surfynol 465 and 16 parts of water were mixed and stirred at 300 rpm for 2 hours. After stirring, the mixture was filtered through a PP filter membrane with a pore size of 0.45μm to obtain a high-moisture water-based coating ink.

[0058] Example 10

[0059] 90.14 g of N-methylthiourea was dissolved in 200 mL of ethylene glycol at 50 °C. Then, 74.16 g of 1,2-propanediamine and 35 g of 25% ammonia solution were added, and the mixture was heated to 200 °C and maintained at this temperature for 4 hours. After the reaction was complete, the mixture was cooled to 30 °C and centrifuged to obtain crude 1,4-dimethylethylenethiourea. After rinsing with ethanol and drying, a low-viscosity moisturizing agent, 1,4-dimethylethylenethiourea, was obtained, with the following structural formula: .

[0060] Eight parts of glycerol, 30 parts of W-6110, 30 parts of nano pigment paste (D50 of 120nm), 15 parts of 1,4-dimethylethylenethiourea, 1 part of surfynol 465 and 16 parts of water were mixed and stirred at 300 rpm for 2 hours. After stirring, the mixture was filtered through a PP filter membrane with a pore size of 0.45μm to obtain a high-moisture water-based coating ink.

[0061] Example 11

[0062] 76.12 g of thiourea was dissolved in 200 mL of ethylene glycol at 50 °C. Then, 74.16 g of 1,3-propanediamine and 35 g of 25% ammonia solution were added, and the mixture was heated to 200 °C and maintained at this temperature for 4 hours. After the reaction was complete, the mixture was cooled to 30 °C and centrifuged to obtain crude propylene-based thiourea. After rinsing with ethanol and drying, a low-viscosity humectant, propylene-based thiourea, was obtained, with the following structural formula: .

[0063] Six parts of glycerol, 30 parts of W-6110, 30 parts of nano pigment paste (D50 of 120nm), 17 parts of propylene thiourea, 1 part of surfynol 465 and 16 parts of water were mixed and stirred at 300 rpm for 2 hours. After stirring, the mixture was filtered through a PP filter membrane with a pore size of 0.45μm to obtain a high-moisture water-based coating ink.

[0064] Example 12

[0065] 90.14 g of N-methylthiourea was dissolved in 200 mL of ethylene glycol at 50 °C. Then, 74.16 g of 1,3-propanediamine and 35 g of 25% ammonia solution were added, and the mixture was heated to 200 °C and maintained at this temperature for 4 hours. After the reaction was complete, the mixture was cooled to 30 °C and centrifuged to obtain crude N-methylpropenylthiourea. After rinsing with ethanol and drying, a low-viscosity moisturizing agent, N-methylpropenylthiourea, was obtained, with the following structural formula: .

[0066] Six parts of glycerol, 30 parts of W-6110, 30 parts of nano pigment paste (D50 of 120nm), 17 parts of N-methylpropenyl thiourea, 1 part of surfynol 465 and 16 parts of water were mixed and stirred at 300 rpm for 2 hours. After stirring, the mixture was filtered through a PP filter membrane with a pore size of 0.45μm to obtain a high-moisture water-based coating ink.

[0067] Example 13

[0068] 59.07 g of iminourea was dissolved in 200 mL of ethylene glycol at 50 °C. Then, 60.10 g of ethylenediamine and 35 g of 25% ammonia solution were added, and the mixture was heated to 200 °C and maintained at this temperature for 4 hours. After the reaction was complete, the mixture was cooled to 30 °C and centrifuged to obtain crude iminourea. After rinsing with ethanol and drying, the low-viscosity humectant iminourea was obtained, with the following structural formula: .

[0069] 10 parts glycerol, 30 parts W-6110, 30 parts nano pigment paste (D50 of 120nm), 13 parts ethyleneimine urea, 1 part surfynol 465 and 16 parts water were mixed and stirred at 300 rpm for 2 hours. After stirring, the mixture was filtered through a PP filter membrane with a pore size of 0.45μm to obtain a high-moisture water-based coating ink.

[0070] Example 14

[0071] 87.12 g of 1-ethylguanidine was dissolved in 200 mL of ethylene glycol at 50 °C. Then, 60.10 g of ethylenediamine and 35 g of 25% ammonia solution were added, and the mixture was heated to 200 °C and maintained at this temperature for 4 hours. After the reaction was complete, the mixture was cooled to 30 °C and centrifuged to obtain crude N-ethylethyleneimine urea. After rinsing with ethanol and drying, the low-viscosity humectant N-ethylethyleneimine urea was obtained, with the following structural formula: .

[0072] 10 parts glycerol, 30 parts W-6110, 30 parts nano pigment paste (D50 of 120nm), 13 parts N-ethylethyleneimine urea, 1 part surfynol 465 and 16 parts water were mixed and stirred at 300 rpm for 2 hours. After stirring, the mixture was filtered through a PP filter membrane with a pore size of 0.45μm to obtain a high-moisture water-based coating ink.

[0073] Example 15

[0074] 59.07 g of iminourea was dissolved in 200 mL of ethylene glycol at 50 °C. Then, 74.16 g of 1,2-propanediamine and 35 g of 25% ammonia solution were added, and the mixture was heated to 200 °C and maintained at this temperature for 4 hours. After the reaction was complete, the mixture was cooled to 30 °C and centrifuged to obtain crude 4-methylethyleneiminourea. This crude material was washed with ethanol and dried to obtain the low-viscosity humectant 4-methylethyleneiminourea, with the following structural formula: .

[0075] Eight parts of glycerol, 30 parts of W-6110, 30 parts of nano pigment paste (D50 of 120nm), 15 parts of 4-methylethyleneimine urea, 1 part of surfynol 465 and 16 parts of water were mixed and stirred at 300 rpm for 2 hours. After stirring, the mixture was filtered through a PP filter membrane with a pore size of 0.45μm to obtain a high-moisture water-based coating ink.

[0076] Example 16

[0077] 87.12 g of 1-ethylguanidine was dissolved in 200 mL of ethylene glycol at 50 °C. Then, 74.16 g of 1,3-propanediamine and 35 g of 25% ammonia solution were added, and the mixture was heated to 200 °C and maintained at this temperature for 4 hours. After the reaction was complete, the mixture was cooled to 30 °C and centrifuged to obtain crude N-ethylpropenylimine urea. After rinsing with ethanol and drying, the low-viscosity humectant N-ethylpropenylimine urea was obtained, with the following structural formula: .

[0078] Six parts of glycerol, 30 parts of W-6110, 30 parts of nano pigment paste (D50 of 120nm), 17 parts of N-ethylpropylene imine urea, 1 part of surfynol 465 and 16 parts of water were mixed and stirred at 300 rpm for 2 hours. After stirring, the mixture was filtered through a PP filter membrane with a pore size of 0.45μm to obtain a high-moisture water-based coating ink.

[0079] Comparative Example 1

[0080] 23 parts glycerol, 30 parts W-6110, 30 parts nano pigment paste (D50 of 120nm), 1 part surfynol 465 and 16 parts water were mixed and stirred at 300 rpm for 2 hours. After stirring, the mixture was filtered through a PP filter membrane with a pore size of 0.45μm to obtain the coating ink.

[0081] Comparative Example 2

[0082] 10 parts glycerol, 13 parts diethylene glycol, 30 parts W-6110, 30 parts nano pigment paste (D50 of 120nm), 1 part surfynol 465 and 16 parts water were mixed and stirred at 300 rpm for 2 hours. After stirring, the mixture was filtered through a PP filter membrane with a pore size of 0.45μm to obtain the coating ink.

[0083] Comparative Example 3

[0084] 12 parts glycerol, 11 parts triethylene glycol, 30 parts W-6110, 30 parts nano pigment paste (D50 of 120nm), 1 part surfynol 465 and 16 parts water were mixed and stirred at 300 r / min for 2 h. After stirring, the mixture was filtered through a PP filter membrane with a pore size of 0.45 μm to obtain the coating ink.

[0085] The following performance tests were conducted on the high moisturizing water-based coating inks obtained in Examples 1-16 and the coating inks obtained in Comparative Examples 1-3: The high-moisture water-based coating inks obtained in Examples 1-16 and the coating inks obtained in Comparative Examples 1-3 were added to ink cartridges, and digital printing was carried out under the conditions of ambient temperature of 25°C and humidity of 50%. The coating inks were printed on the fabric using a digital printing printer equipped with a Kyocera KJ4B-0300 printhead. The printed fabric products were placed in a color-fixing machine and fixed at a temperature of 160°C for 2 minutes to obtain the final product for testing.

[0086] Viscosity test: A rotational viscometer with a #0 rotor was used to conduct the test at 25°C and 50% humidity. Test of thermal storage stability: Take 500mL of ink into a sample bottle, seal it, and place it in a 60℃ environment for 7 days. After taking it out, test various physicochemical indicators. The change of indicators within 10% is considered qualified. Color density test: Using a color density meter, measure the OD value at three random points on the product and take the average value; Machine cleaning test: Smooth ink filling, and after ink filling, two cleanings were performed without any broken lines or oblique spraying, which is considered qualified. Inkjet stability test: The machine is set to 3-pass printing mode, the test resolution is 360×1800dpi, and a four-color black mixed block with 100% ink volume is continuously printed at a distance of 100 meters. The integrity of the lines is observed. The number of broken lines per color is ≤3 pins to be considered qualified. Static moisture retention test: After filling the printhead with ink, expose it to an air environment of 25℃ and 50% humidity for 30 minutes and observe the integrity of the lines. The number of broken lines per color ≤ 3 is considered qualified. The test results are shown in Table 1.

[0087] Table 1. Performance test results of the high moisturizing water-based coating inks obtained in Examples 1-16 and the coating inks obtained in Comparative Examples 1-3

[0088] As shown in Examples 1-16, this invention provides a low-viscosity humectant with water solubility and moisturizing properties, which, when applied to ink, reduces the rate of water evaporation during printing, protecting the printhead from drying out and preventing printhead clogging. High moisturizing properties make it more suitable for long-duration, high-intensity wide-format printing, single-pass printing, and other similar processes. While improving moisturizing properties, the low-viscosity humectant in this invention can be mixed with general-purpose humectants in any ratio to adjust viscosity. A suitable viscosity allows for uniform ink droplet ejection, improving color intensity and uniformity. The prepared ink has vibrant colors, smooth ink ejection, and can be stored stably for extended periods. This invention requires no additional processing steps, generates no wastewater, and is environmentally friendly.

[0089] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A high-moisture water-based coating ink, characterized in that, The components include the following parts by mass: 5-20 parts aqueous solvent, 15-30 parts resin, 20-40 parts color paste, 5-20 parts low viscosity moisturizer, 0.1-1 part surfactant and 5-50 parts water; The structural formula of the low-viscosity moisturizer is: Where n is any integer from 1 to 6; R4 is O, S, or NH; R1, R2, or R3 are independently H, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 alkenyl, or C1-C6 alkynyl.

2. The high-moisture water-based coating ink according to claim 1, characterized in that, The aqueous solvent includes one or more of ethanol, n-propanol, isopropanol, n-butanol, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, polyethylene glycol 200, polyethylene glycol 400, polyethylene glycol 600, diethylene glycol, triethylene glycol, glycerol, pentaerythritol, 2-pyrrolidone, and N-methylpyrrolidone.

3. A high-moisture water-based coating ink according to claim 1 or 2, characterized in that, The resin includes one or more of polyurethane resin, acrylic resin, polyolefin resin, epoxy resin, formaldehyde resin, urea-formaldehyde resin, and fluorocarbon resin.

4. The high-moisture water-based coating ink according to claim 3, characterized in that, The color paste includes nano pigment color paste.

5. The high-moisture water-based coating ink according to claim 4, characterized in that, The surfactant includes one or more of the following: acetylenic diols, polyether siloxanes, acrylic acids, and organofluorine compounds.

6. A method for preparing a high-moisture water-based coating ink according to any one of claims 1 to 5, characterized in that, The preparation steps of the preparation method are as follows: mixing aqueous solvent, resin, pigment, low viscosity moisturizing agent, surfactant and water to obtain aqueous coating ink.

7. The method for preparing a high-moisture water-based coating ink according to claim 6, characterized in that, The mixing is carried out under stirring at a speed of 200-500 rpm for a duration of 0.5-5 hours.

8. The application of the high moisturizing water-based coating ink according to any one of claims 1 to 5 in the field of digital textile printing.

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