Ink with high dye utilization rate for inkjet printing and preparation method thereof

Abstract

The invention discloses ink with high dye utilization rate for inkjet printing and a preparation method of the ink. The ink is prepared from the following components in percentage by mass: 1.7-3.7% of a cationic auxiliary agent; 3.5%-3.8% of a reactive dye; 22.9% to 28.5% of a viscosity modifier; 0.4%-0.7% of a surfactant; and the balance of deionized water. The method effectively solves the problems of long treatment flow, high consumption of chemicals and energy sources and large discharge amount of colored wastewater caused by low utilization rate of the reactive dye; the dye utilization rate reaches 98.5% or above, and the ink-jet printing ink can be widely applied to ink-jet printing of cellulose fiber fabrics such as cotton, hemp and lyocell; the fabric does not need to be subjected to pretreatment and water washing treatment; and the preparation method is simple, the treatment process is short, the ink stability is good, and the ink can be used in a high-speed printing mode with the injection frequency of 30 KHz.

Description

Technical Field

[0001] The present invention relates to the technical field of digital inkjet printing, and particularly to a high-dye-utilization ink for inkjet printing and a preparation method thereof. Background Art

[0002] Inkjet printing technology has been widely used in the textile industry due to its advantages such as high efficiency, high precision, low energy and chemical consumption, and less wastewater discharge. Reactive dye inks are often used as special colorants for fabrics made of cellulose fibers such as cotton, linen, and lyocell, as well as protein fibers such as silk. However, in order to reduce the diffusion of ink droplets on the fabric and provide an alkaline condition for the reaction between dye molecules and fibers, it is generally necessary to pretreat the fabric with a solution composed of sodium alginate or modified cellulose, urea, and sodium bicarbonate. However, since the hydroxyl groups on cellulose fibers will ionize into oxygen anions and carry a negative charge under alkaline conditions, and dye ions also carry a negative charge, due to the repulsion between like charges, it is difficult for dye molecules to bind to cellulose fibers. At the same time, reactive dyes will also undergo hydrolysis reactions under alkaline conditions, resulting in a dye utilization rate of only about 60%. This makes it necessary for the printed fabric to undergo a water washing process to remove unreacted dyes, sodium alginate, urea, and sodium bicarbonate, causing problems such as a long treatment process, high energy consumption, and a large amount of colored wastewater discharge.

[0003] In order to improve the dye utilization rate, the following patents have been disclosed in the prior art: CN115928461A discloses a digital direct inkjet printing process for cellulose fiber fabrics using plant dye inks. The process includes: (1) impregnating and padding the fabric with a pretreatment modifier and drying to obtain a modified dry fabric; (2) preparing a digital printing ink, the ink components including plant dyes, humectants, surfactants, antiseptic and fungicide agents, pH buffer agents, and pure water; (3) spraying the plant dye ink onto the modified dry fabric through an inkjet printer; (4) performing steam steaming, washing with water, drying, impregnating with a fixing agent, and high-temperature baking for fixation. The above patent uses a technical means of pretreating and modifying the fabric with a cationic modifier before inkjet printing. In an alkaline environment, it utilizes the characteristic that the fabric modified with cations has a high affinity for anionic dyes to improve the dye uptake rate. However, when using a cationic modifier to pretreat the fabric, the two-dip two-roll method is adopted, and the entire fabric is modified. The pattern of inkjet printing does not cover the entire fabric surface, and cationicity will still exist in the areas without printed patterns. During home washing, other fading clothes will stain this area and cause the clothes to change color. Moreover, after cationically modifying the fabric, when anionic ink is printed on the fabric, anionic dyes will be quickly adsorbed on the fabric surface. In this structure where anionic dyes are on the outside and cationic modifiers are on the inside, dye molecules are easily replaced by soaping agents with a greater negative charge, resulting in poor soaping fastness and generally poor rubbing fastness.

[0004] CN108589347A discloses a finishing method for reactive dye inkjet printing using cation-modified ink. By means of the inkjet printing process, the cation-modified ink and the reactive dye ink are inkjet-printed on the pattern area of the sized cellulose fiber fabric, then steamed or baked, and finally soaped to obtain the reactive dye inkjet-printed fabric; the printing interval time between the cation-modified ink and the reactive dye ink is 0-2 min; the cation-modified ink is an ink containing 1.0-60.0 wt% of the cation modifier; the cation modifier is a molecule with a reactive group and a positive charge group in its molecular structure and a number average molecular weight of 100-30000, and its reactive group is one or more of epoxy group, s-triazine, pyridine and olefin, and the positive charge group includes one or more of quaternary ammonium salt and ammonium chloride structure. This method shortens the treatment process of fabric cation modification, but the fabric still needs pretreatment, the treatment process is long, and the improvement degree of dye utilization rate is limited.

[0005] CN102558959A discloses a reactive dye ink, especially a direct inkjet reactive dye ink without sizing. The direct inkjet reactive dye ink of the present invention is prepared by mixing surfactant, glycerol, resin, diethylene glycol, 2-pyrrolidone, ethanol, 1,5-pentanediol, 2-ethylaminoethyl ether, diethylene glycol monobutyl ether, triethanolamine, reactive dye and deionized water according to weight percentages, and it is used for digital printing process on cotton, silk and wool fabrics that have not been sized with a synthetic sizing agent mainly composed of sodium alginate or cardamom, alkali and urea. Although the above patent technology omits the pretreatment process and solves the problems of cumbersome steps, time-consuming and large consumption of water resources caused by traditional pretreatment (sizing) before printing, in order to ensure the alkaline condition for the reaction of dye molecules with fibers, this method needs to apply a solution composed of sodium bicarbonate and inorganic salts to the fabric by spraying, and then obtain the printed product after steaming and washing. This method applies the fixing agent to the fabric by spraying, which is likely to cause uneven spraying, reduce the clarity of the printed pattern and result in a low dye utilization rate.

[0006] In summary, compared with the prior art, how to improve the dye utilization rate while ensuring the quality requirements such as the clarity and color fastness of the printed product is the key to solving the problems of long treatment process, high energy consumption and large discharge of colored wastewater caused by low dye utilization rate in the prior art. Summary of the Invention

[0007] Aiming at the deficiencies of the prior art, the technical problem to be solved by the present invention is to solve the problems of long treatment process, high energy consumption and large discharge of colored wastewater caused by low dye utilization rate while ensuring the pattern printing quality, and provide an ink with high dye utilization rate for inkjet printing and its preparation method.

[0008] To solve the above technical problems, the technical solution adopted by the present invention is: A high-dye-utilization ink for inkjet printing, which is composed of the following components by mass fraction:

[0009]

[0010] For the above high-dye-utilization ink for inkjet printing, the cationic auxiliary is any one or more of poly(acrylamide-diallyldimethylammonium chloride), polydiallyldimethylammonium chloride, polydimethyldiallylammonium chloride, polyacrylamide, poly(N-isopropylacrylamide), poly(N,N-dimethylacrylamide), 2-(dimethylamino)ethyl methacrylate, polyethyleneimine, polypropyleneimine, dimethylaminopropylacrylamide, polyamide-amine type dendritic polymer, poly(N-isopropylacrylamide).

[0011] For the above high-dye-utilization ink for inkjet printing, the dyes include any one or more of reactive red 2, reactive red 3, reactive red 24, reactive red 241, reactive red 194, reactive red 195, reactive red 218, reactive yellow 5, reactive yellow 14, reactive yellow 86, reactive yellow 145, reactive blue 4, reactive blue 5, reactive blue 19, reactive blue 49, reactive blue 74, reactive black 5, reactive black 8.

[0012] For the above high-dye-utilization ink for inkjet printing, the viscosity regulator is any one or more of ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, diethylene glycol.

[0013] For the above high-dye-utilization ink for inkjet printing, the surfactant is any one or more of Tween 60, Tween 80, Surfynol 465, Surfynol 604.

[0014] For the above high-dye-utilization ink for inkjet printing, the viscosity of the dye ink is 3.5 - 5.5 mPa·s, the surface tension is 35.1 - 41.3 mN / m, the conductivity is 3426 - 4785 uS / cm, and the pH is 8.5 - 11.2.

[0015] A preparation method of a high-dye-utilization ink for inkjet printing includes the following steps:

[0016] (1) Prepare a cationic auxiliary solution: Add a certain amount of cationic auxiliary to deionized water and stir. After mixing evenly, a cationic auxiliary solution with a mass fraction of 5% - 10% is obtained and reserved;

[0017] (2) Prepare an aqueous dye solution: Weigh a certain amount of reactive dye, add it to deionized water and stir. After mixing evenly, an aqueous dye solution with a mass fraction of 10% is obtained and reserved for use.

[0018] (3) Prepare a cationic auxiliary / dye mixed aqueous solution: Drop the cationic auxiliary solution into the aqueous dye solution according to a certain mass ratio, and continue to add a certain amount of viscosity regulator and surfactant. After stirring for 1 - 2 h, let it stand for 12 - 24 h.

[0019] (4) Filter: Filter the mixed aqueous solution after standing using a filter membrane to obtain the dye ink.

[0020] In the above - mentioned preparation method with high dye utilization rate for ink - jet printing, in step (3), the mass ratio of the cationic auxiliary solution to the aqueous dye solution is 2:3 - 3:2.

[0021] In the above - mentioned preparation method with high dye utilization rate for ink - jet printing, in step (3), the addition amount of the viscosity regulator is 30% - 40% of the mass of the mixed aqueous solution, and the addition amount of the surfactant is 0.5% - 1% of the mass of the mixed aqueous solution.

[0022] In the above - mentioned preparation method with high dye utilization rate for ink - jet printing, in step (4), the filter membrane is a polypropylene filter membrane with a pore size of 0.22 - 0.5 μm.

[0023] The advantages of the high - dye - utilization - rate ink for ink - jet printing and its preparation method of the present invention are as follows: The present invention effectively solves the problems of long treatment process, high consumption of chemicals and energy, and large discharge of colored wastewater caused by low utilization rate of reactive dyes; the dye utilization rate reaches more than 98.5%, and it can be widely used for ink - jet printing of cellulose - fiber fabrics such as cotton, linen, and lyocell; moreover, the preparation method is simple, the treatment process is short, the ink has good stability, and it can be used in a high - speed printing mode with a jetting frequency of 30 KHz. Description of the Drawings

[0024] Figure 1 It is a comparison chart of the color of the washing waste liquid of the printed fabric between Comparative Example 1 of the prior art and Examples 1 - 4 of the present invention. Detailed Embodiments

[0025] The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0026] In the description of the present invention, the term "comprising" means "including but not limited to". The terms first, second, third, etc. are only used as labels and do not impose numerical requirements or establish an order. The term "plural" means "two or more".

[0027] A high-dye-utilization dye ink for inkjet printing, which is composed of components with the following mass fractions: cationic auxiliary 1.7%-3.7%; reactive dye 3.5%-3.8%; viscosity regulator 22.9%-28.5%; surfactant 0.4%-0.7%;

[0028] The balance is deionized water.

[0029] Among them, the cationic auxiliary is any one or more of poly(acrylamide-diallyldimethylammonium chloride), polydiallyldimethylammonium chloride, polydimethyldiallylammonium chloride, polyacrylamide, poly(N-isopropylacrylamide), poly(N,N-dimethylacrylamide), 2-(dimethylamino)ethyl polymethacrylate, polyethyleneimine, polypropyleneimine, dimethylaminopropylacrylamide, polyamide-amine type dendrimer, poly(N-isopropylacrylamide). The dyes include any one or more of reactive red 2, reactive red 3, reactive red 24, reactive red 241, reactive red 194, reactive red 195, reactive red 218, reactive yellow 5, reactive yellow 14, reactive yellow 86, reactive yellow 145, reactive blue 4, reactive blue 5, reactive blue 19, reactive blue 49, reactive blue 74, reactive black 5, reactive black 8. The viscosity regulator is any one or more of ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, diethylene glycol. The surfactant is any one or more of Tween 60, Tween 80, Surfynol 465, Surfynol 604.

[0030] Use an inkjet printer to directly print the dye ink prepared by the present invention onto an untreated cotton fabric, and then use a steaming machine to process the printed fabric. The steaming conditions: among them, the steam fixation treatment conditions: temperature 102±1°C, humidity 90-96%, time 7-12 min, and then the inkjet printing product can be obtained.

[0031] As is well known, cationic modification is a common method for fabric pretreatment, which can change the surface hydrophilicity and hydrophobicity, positive and negative charges and other properties of the fabric. After inkjet printing, it can quickly adsorb negatively charged dye ions, thereby improving the dye utilization rate. The present invention abandons the traditional concept of cationic modification of fabrics, and by means of modifying the dye ink, directly prints the ink on the untreated fabric, which not only improves the dye utilization rate but also ensures the printing accuracy, greatly shortens the inkjet printing process, and solves the problems of high energy consumption and large discharge of colored wastewater. The specific mechanism is as follows:

[0032] Cationic additives can absorb protons in aqueous solution to become protonated, making them positively charged. When positively charged cationic additives are added to anionic dye aqueous solution, they are first rapidly adsorbed and brought close together by electrostatic attraction, and the original entropy balance is destroyed. In order to achieve a new entropy balance, the cationic additives and dye ions will self-assemble to form a new charged aggregation structure, and the ink will present an alkaline environment at the same time. Under alkaline conditions, the hydroxyl groups on cellulose fibers will be ionized into oxygen anions, making the fiber surface negatively charged. When the ink is printed on the fabric, the two are quickly combined by electrostatic attraction, reducing the diffusion of the ink on the fabric and improving the printing accuracy. In addition, in the subsequent steaming process, the electrostatic attraction will gradually transform into hydrogen bonds and van der Waals forces, so that all dye molecules are fixed on the fabric, greatly improving the utilization rate of the dye.

[0033] That is to say, the present invention not only changes the negatively charged dye ions into positively charged charged aggregated structures by adding cationic additives to the dye ink during the preparation process of the dye ink, but also the dye ink itself has alkalinity. This positively charged dye ink greatly improves the electrostatic binding force with the fiber when in contact with the fiber, thereby significantly improving the utilization rate of the dye. Moreover, since the dye ink is prepared by dripping and mixing, the charged aggregated structure formed in the dye ink makes the dye molecules more stable and uniform, reduces the diffusion of the ink on the fabric, and solves the cumbersome steps of cationic modification pretreatment of the fabric in traditional inkjet printing in order to improve the utilization rate of the dye. Moreover, the alkaline environment of the ink itself does not require the addition of an alkali agent to the ink or the use of alkali solution to pretreat the fabric, saving the amount of additives.

[0034] The traditional method is to first size the fabric, and after the fabric is modified by cations in the slurry, anionic ink is printed on the fabric, and anionic dyes are quickly adsorbed on the fabric surface. At this time, the structure of anionic dyes on the outside and cations on the inside is easily replaced by soaping agents with greater negative charge during soaping (the same purpose as the fabric cation pretreatment modification and then washing mentioned in the background technology), resulting in dye shedding, low dye utilization, and poor soaping fastness and rubbing fastness. Compared with the traditional method of first sizing (similar to cation pretreatment), the present invention can form an aggregated structure between the cationic auxiliary agent and the dye molecules that can firmly adhere to the fiber, solving the problem of poor soaping fastness and rubbing fastness.

[0035] Therefore, compared with the traditional cationic modification of fabrics, by changing the concept of dye ink, the present invention not only solves the problems of long process flow, low dye utilization rate, and large dosage of auxiliaries caused by the traditional need for cationic pretreatment modification of fabrics, but also solves the problems of the large amount of cationic modifier and the need for water washing to remove the unreacted dyes on the fiber surface due to the low dye utilization rate. Therefore, while effectively ensuring the printing effect, it also significantly saves the dosage of auxiliaries and water, shortens the process flow, and improves the production efficiency of inkjet printing.

[0036] The following is a specific description of the present application through specific embodiments. The following embodiments are only part of the embodiments of the present application and do not limit the present application.

[0037] Example 1:

[0038] A high-dye-utilization ink for inkjet printing is composed of the following components by mass fraction: polyacrylamide 3.0%, reactive red 218 dye 3.8%, ethylene glycol 22.9%, Surfynol 465 0.7%, and deionized water 69.6%.

[0039] The preparation method of the high-dye-utilization ink for inkjet printing in this example includes the following steps:

[0040] (1) Prepare a cationic auxiliary solution: Add 8% polyacrylamide to 92% deionized water by mass percentage and stir to obtain a uniformly mixed cationic auxiliary solution.

[0041] (2) Prepare a dye aqueous solution: Weigh 10% reactive red 218 by mass percentage, add 90% deionized water and stir to obtain a uniformly mixed dye aqueous solution.

[0042] (3) Prepare a cationic auxiliary / dye mixed aqueous solution: Drop the cationic auxiliary solution into the dye aqueous solution according to a mass ratio of 1:1, continue to add 30% ethylene glycol and 1% Surfynol 465 based on the mass of the mixed solution, stir for 2 h and then let it stand for 24 h.

[0043] (4) Filter the dye ink: Filter the standing mixed aqueous solution with a 0.22 μm polypropylene filter membrane to obtain the dye ink.

[0044] Use an inkjet printer to directly print the dye ink onto the unpretreated cotton fabric, and then use a steaming machine to process the printed fabric. The steaming conditions are: temperature 102 °C, humidity 95%, and time 8 min to obtain the inkjet printing product.

[0045] Example 2:

[0046] A high-dye-utilization ink for inkjet printing, which is composed of components with the following mass fractions: 1.7% of polyethyleneimine, 3.5% of reactive blue 49 dye, 28.4% of ethylene glycol, 0.6% of Surfynol 465, 0.01% of Surfynol 604, and 65.79% of deionized water.

[0047] The preparation method of the pre-treatment-free and water-washing-free dye ink for inkjet printing in this example includes the following steps:

[0048] (1) Prepare a cationic auxiliary solution: According to the mass percentage, add 5% of polyethyleneimine to 95% of deionized water and stir to obtain a uniformly mixed cationic auxiliary solution.

[0049] (2) Prepare a dye aqueous solution: According to the mass percentage, weigh 10% of reactive blue 49 and add 90% of deionized water for stirring to obtain a uniformly mixed dye aqueous solution.

[0050] (3) Prepare a cationic auxiliary / dye mixed aqueous solution: According to a mass ratio of 1:1, drop the cationic auxiliary solution into the dye aqueous solution, and continue to add 40% of ethylene glycol, 0.8% of Surfynol 465, and 0.01% of Surfynol 604 based on the mass of the mixed solution, stir for 1 h, and then stand for 24 h.

[0051] (4) Filter the dye ink: Filter the standing mixed aqueous solution with a 0.22-μm polypropylene filter membrane to obtain the dye ink.

[0052] Use an inkjet printer to directly print the dye ink onto the unpretreated cotton fabric, and then use a steaming machine to process the printed fabric. The steaming conditions are: temperature 102 °C, humidity 95%, and time 8 min, thus obtaining the inkjet printing product.

[0053] Example 3:

[0054] A high-dye-utilization ink for inkjet printing, which is composed of components with the following mass fractions: 3.7% of polypropyleneimine, 3.7% of reactive black 8 dye, 25.8% of 1,2-propanediol, 0.4% of Surfynol 465, and 66.4% of deionized water.

[0055] The preparation method of the pre-treatment-free and water-washing-free dye ink for inkjet printing in this example includes the following steps:

[0056] (1) Prepare a cationic auxiliary solution: According to the mass percentage, add 10% of polypropyleneimine to 90% of deionized water and stir to obtain a uniformly mixed cationic auxiliary solution.

[0057] (2) Prepare an aqueous dye solution: Weigh 10% of reactive black 8 by mass percentage, add 90% deionized water and stir to obtain a uniformly mixed aqueous dye solution.

[0058] (3) Prepare a cationic auxiliary / dye mixed aqueous solution: Drop the cationic auxiliary solution into the aqueous dye solution according to a mass ratio of 3:2, and continue to add 35% of 1,2 - propanediol and 0.6% of Surfynol 465 based on the mass of the mixed solution. Stir for 1 h and then let it stand for 20 h.

[0059] (4) Filter the dye ink: Filter the mixed aqueous solution after standing using a 0.22 - μm polypropylene filter membrane to obtain the dye ink.

[0060] Use an inkjet printer to directly print the dye ink onto an untreated cotton fabric, and then process the printed fabric using a steaming machine. The steaming conditions are: temperature 102 °C, humidity 95%, time 8 min, thus obtaining an inkjet printing product.

[0061] Example 4

[0062] A high - dye - utilization - rate ink for inkjet printing is composed of the following components by mass fraction: 1.8% of dimethylaminopropyl acrylamide, 3.6% of reactive black 5 dye, 28.5% of diethylene glycol, 0.4% of Surfynol 465, and 65.7% of deionized water.

[0063] The preparation method of the pre - treatment - free and water - washing - free dye ink for inkjet printing in this example includes the following steps:

[0064] (1) Prepare a cationic auxiliary solution: Add 5% of dimethylaminopropyl acrylamide to 95% of deionized water according to mass percentage and stir to obtain a uniformly mixed cationic auxiliary solution.

[0065] (2) Prepare an aqueous dye solution: Weigh 10% of reactive black 5 by mass percentage, add 90% deionized water and stir to obtain a uniformly mixed aqueous dye solution.

[0066] (3) Prepare a cationic auxiliary / dye mixed aqueous solution: Drop the cationic auxiliary solution into the aqueous dye solution according to a mass ratio of 2:3, and continue to add 40% of diethylene glycol and 0.5% of Surfynol 465 based on the mass of the mixed solution. Stir for 1 h and then let it stand for 12 h.

[0067] (4) Filter the dye ink: Filter the mixed aqueous solution after standing using a 0.22 - μm polypropylene filter membrane to obtain the dye ink.

[0068] Use an inkjet printer to directly print dye ink onto an unpretreated cotton fabric, and then use a steaming machine to process the printed fabric. The steaming conditions are: temperature 102°C, humidity 95%, and time 8 min, thus obtaining an inkjet printed product.

[0069] Comparative example

[0070] According to mass percentage, use a pretreatment solution composed of 2% sodium alginate, 3% sodium bicarbonate, and 10% urea to pretreat the cotton fabric. Use a printer to print commercial magenta, blue, gray, and black inks onto the pretreated fabric, and then use a steaming machine to process it. The steaming conditions are: temperature 102°C, humidity 95%, and time 8 min, thus obtaining an inkjet printed product.

[0071] The test results of the physical and chemical indexes of the dye inks in Examples 1-4 of the present invention, the evaluation of the printing effect, and the test comparison results of the fixation rate and color fastness with commercial inks are as follows:

[0072] The test results of the physical and chemical indexes of the dye inks in Examples 1-4 of the present invention and the evaluation of the printing effect are shown in Table 1:

[0073] Table 1 Test results of the physical and chemical indexes of the dye inks in Examples 1-4 and evaluation of the printing effect (25°C)

[0074] Name Viscosity mPa·s Surface tension mN / m Conductivity μS / cm pH Printing effect Example 1 3.5 35.1 4785 8.9 Qualified Example 2 4.3 36.2 3653 10.2 Qualified Example 3 4.6 37.5 4165 8.5 Qualified Example 4 5.5 41.3 3426 11.2 Qualified

[0075] Viscosity, surface tension, conductivity, and pH are the most conventional physical and chemical indexes of dye inks, and their magnitudes determine the stability and jetting performance of dye inks. From the test results in Table 1, it can be seen that the physical and chemical indexes of the dye inks of the present invention all meet the standards of QB / T4973.1-2016 and QB-T 2730.1-2005, and can stably jet under the condition of a printing frequency of 30k, and the printing effect is qualified.

[0076] The test results of the fixation rate of the dye inks in Examples 1-4 of the present invention and commercial inks are shown in Table 2:

[0077] Table 2 Test of the dye utilization rate of the dye inks in Examples 1-4 and commercial inks

[0078] Name Example 1 Example 2 Example 3 Example 4 Dye utilization rate (%) 98.6 99.3 99.2 98.8 Name Commercial magenta Commercial blue Commercial grey Commercial black Dye utilization rate (%) 58.5 62.3 63.6 60.5

[0079] Reactive dyes have problems such as long treatment processes, high energy consumption, and large amounts of colored wastewater discharge due to their low utilization rate. Improving the utilization rate of dyes is the key to solving this problem. From the comparison of the test results in Table 2, it can be seen that under the same inkjet printing conditions, the dye inks prepared in Examples 1-4 were printed on untreated fabrics and after steam fixation treatment, the dye utilization rates all reached over 98.5%. Compared with the highest dye utilization rate of 63.6% of commercial inks, the dye utilization rate was significantly improved. Thus, it can be proved that the dye ink prepared by the present invention can significantly save a large amount of energy and reduce the consumption of chemicals.

[0080] Color fastness is an important indicator for measuring the quality of printed products. Table 3 shows the tests of rubbing and soaping fastness of the dye inks of Examples 1-4 and commercial inks. It can be seen that the rubbing and soaping color fastness of the inks in the examples is basically the same as that of the conventional inks, which can meet the quality requirements of printed products.

[0081] Table 3 Tests of rubbing and soaping fastness of the dye inks of Examples 1-4 and commercial inks

[0082]

[0083] As Figure 1 shown, in the comparison of the color of the washing waste liquid of the printed fabrics in the comparative example and the examples, a 1 -d 1 are the washing waste liquids of the red, blue, gray, and black printed fabrics in the comparative example respectively, and a 2 -d 2 are the washing waste liquids of the printed fabrics of Examples 1-4 respectively. The printed fabrics in the comparative example produce colored wastewater due to the low dye utilization rate, while the washing waste liquids of the printed fabrics of Examples 1-4 are all clear and transparent, indicating that the dye molecules on the surface have been completely fixed on the fabrics.

[0084] In summary, compared with traditional reactive dye inks and digital inkjet printing processes, the present invention effectively solves the problems of long treatment processes, high consumption of chemicals and energy, and large amounts of colored wastewater discharge caused by the low utilization rate of reactive dyes; the dye utilization rate reaches over 98.5%; the ink has good stability and can be used in high-speed printing modes with a jetting frequency of 30KHz; the preparation method of the present invention is simple, the treatment process is short, a large amount of chemical and energy costs are saved, and it has obvious prospects for industrial application.

[0085] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions, or substitutions made by those of ordinary skill in the art within the scope of the essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A high dye utilization ink for inkjet printing, characterized in that: It is composed of the following components by mass fraction:

2. The high dye utilization ink for inkjet printing according to claim 1, characterized in that: The cationic auxiliary agent is any one or more of poly(acrylamide-diallyldimethylammonium chloride), polydiallyldimethylammonium chloride, polydimethyldiallylammonium chloride, polyacrylamide, poly(N-isopropylacrylamide), poly(N,N-dimethylacrylamide), polymethacrylate 2-(dimethylamino)ethyl ester, polyethyleneimine, polypropyleneimine, dimethylaminopropylacrylamide, polyamide-amine type dendrimer, and polyN-isopropylacrylamide.

3. The high dye utilization ink for inkjet printing according to claim 1, characterized in that: The dye includes any one or more of Reactive Red 2, Reactive Red 3, Reactive Red 24, Reactive Red 241, Reactive Red 194, Reactive Red 195, Reactive Red 218, Reactive Yellow 5, Reactive Yellow 14, Reactive Yellow 86, Reactive Yellow 145, Reactive Blue 4, Reactive Blue 5, Reactive Blue 19, Reactive Blue 49, Reactive Blue 74, Reactive Black 5, and Reactive Black 8.

4. The high dye utilization ink for inkjet printing according to claim 1, characterized in that: The viscosity modifier is any one or more of ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, and diethylene glycol.

5. The high dye utilization ink for inkjet printing according to claim 1, characterized in that: The surfactant is any one or more of Tween 60, Tween 80, Surfynol 465, and Surfynol 604.

6. The high dye utilization ink for inkjet printing according to claim 1, characterized in that: The dye ink has a viscosity of 3.5-5.5 mPa·s, a surface tension of 35.1-41.3 mN / m, a conductivity of 3426-4785 uS / cm, and a pH of 8.5-11.

2.

7. A method for preparing the ink with high dye utilization rate for inkjet printing according to any one of claims 1 to 6, characterized in that: The steps include: (1) preparing a cationic auxiliary agent solution: adding a certain amount of cationic auxiliary agent into deionized water and stirring, mixing evenly, obtaining a cationic auxiliary agent solution with a mass fraction of 5% to 10%, and setting aside; (2) Preparation of dye aqueous solution: Weigh a certain amount of active dye, add it into deionized water and stir, mix well to obtain a dye aqueous solution with a mass fraction of 10%, and set aside; (3) Prepare a cationic auxiliary agent / dye mixed aqueous solution: add the cationic auxiliary agent solution dropwise to the dye aqueous solution according to a certain mass ratio, continue to add a certain amount of viscosity modifier and surfactant, stir for 1-2 hours, and let stand for 12-24 hours; (4) Filtration: Filter the mixed aqueous solution after standing using a filter membrane to obtain the dye ink.

8. The method for preparing the ink with high dye utilization rate for inkjet printing according to claim 7, characterized in that: In the step (3), the mass ratio of the cationic auxiliary solution to the dye aqueous solution is 2:3-3:

2.

9. The method for preparing the ink with high dye utilization rate for inkjet printing according to claim 7, characterized in that: In the step (3), the viscosity modifier is added in an amount of 30%-40% of the mass of the mixed aqueous solution, and the surfactant is added in an amount of 0.5%-1% of the mass of the mixed aqueous solution.

10. The method for preparing the ink with high dye utilization rate for inkjet printing according to claim 7, characterized in that: In the step (4), the filter membrane is a polypropylene filter membrane with a pore size of 0.22-0.5 μm.

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