A digital inkjet ink for tattooing and a method of preparing the same and a printing process

Abstract

The present application belongs to the field of textile, especially relates to the field of D06P5 / 00, and more particularly relates to a discharge digital inkjet ink and a preparation method and printing process thereof. The preparation raw material of the ink comprises 0.5-10% discharge agent, 1-10% ink stabilizer, 0.5-5% alkali agent, 5-50% humectant, 0.2-5% wetting agent and the rest deionized water in percentage by mass. The ink has excellent stability, the discharge effect of the ink does not obviously attenuate after more than 120 days of storage at 45 DEG C, and no waste water and waste gas is generated in the whole process of preparation and printing, the discharge rate of the printed product is high, the hand feeling is soft, and good social and economic benefits are obtained.

Description

Technical Field

[0001] This invention belongs to the textile field, particularly to the D06P5 / 00 field, and more specifically to a whitening digital inkjet ink, its preparation method, and printing process. Background Technology

[0002] Discharge printing, often called discharge bleaching, works by azo dyes undergoing a redox reaction under the influence of reducing or oxidizing agents. The nitrogen-nitrogen double bonds in the molecule break, generating non-azo compounds that decolorize, which can be represented as Ar—N=N—Ar'→Ar—NH2+H2N—Ar'. Many dyes can be used as ground colors in discharge printing, including the most common azo dyes, as well as reactive dyes and direct dyes. Because the dyes themselves exist in a strongly reducing medium, they are suitable as discharge dyes. Discharge printing produces more refined patterns with clear outlines and no white showing at the edges, resulting in better effects. However, the process is complex and cumbersome, and defects are easily encountered during actual production, leading to a lower yield and significantly higher costs. Discharge printing is currently mostly used for high-end fabrics. Traditional discharge printing processes include priming, drying, developing, drying again, and washing, generating a large amount of organic and inorganic wastewater, which is clearly environmentally unfriendly. Digital printing technology, a high-tech innovation that has emerged with the continuous development of computer technology, has brought tremendous convenience to the textile printing and dyeing industry. Its advanced production principles and methods have created a new development opportunity for the textile sector. Therefore, providing an ink with good discharge printing effect, low pollution during preparation, and suitability for digital printing is a pressing technical problem that textile enterprises need to solve.

[0003] International patent CN108474162A discloses a discharge dyeing agent for inkjet compositions. The technical solution mainly involves applying a composition of two or more reagents to a substrate, causing the reagents to react on the substrate for discharge dyeing. The main discharge dyeing auxiliary agent is thiourea dioxide. This is achieved by simultaneously printing two or more auxiliaries onto the fabric to generate a reducing agent. However, this method requires sophisticated printing equipment, has a slow reaction speed, and is difficult to implement in industrial production. Existing technologies CN107119471A "A Discharge Printing Process Based on Inkjet Technology with Reactive Paste," CN106049115A "A Preparation Method of Inkjet Discharge Printed Fabrics," and CN105755861A "A Preparation Method of Transfer Discharge Printed Fabrics" all introduce discharge printing processes based on inkjet technology, mainly focusing on the discharge dyeing process, but without detailed discussion of the discharge dyeing ink used. A master's thesis from Suzhou University, "Preparation and Application of Formaldehyde-Free Discharge Inkjet Printing Ink," explores the reducing properties of a novel formaldehyde-free reducing discharge agent, thiourea dioxide. This study investigated the effects of thiourea dioxide concentration, pH, and temperature on reduction potential, as well as the potential changes when thiourea dioxide was mixed with different mass fractions of anhydrous sodium sulfite and sodium metabisulfite. The reduction performance of thiourea dioxide was compared with that of commonly used reducing whitening agents such as sodium hydrosulfite, sodium carbonate, and decoupage. For the newly developed whitening ink for digital inkjet printing, the pre- and post-treatment processes for whitening inkjet printing on silk fabrics were studied. The resulting products require high storage conditions, needing to be stored at a low temperature of 0–3℃, which is difficult to achieve in practical factory applications. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the first aspect of the present invention provides a whitening digital inkjet ink, the raw materials for which are prepared by mass percentage include: 0.5-10% discharge agent, 1-10% ink stabilizer, 0.5-5% alkali agent, 5-50% humectant, 0.2-5% wetting agent, and the balance being deionized water.

[0005] Preferably, the stripping agent includes one or more of the following: thiourea dioxide, sodium dithionite, sodium sulfite, sodium thiosulfate, and sodium pyrophosphate.

[0006] More preferably, the stripping agent includes at least sodium pyrophosphate.

[0007] Preferably, the ink stabilizer includes one or more of the following: carbazide, glucose, ascorbic acid, salicylic acid, benzoic acid, and toluenesulfonyl hydrazine.

[0008] More preferably, the ink stabilizer includes at least carbonyl hydrazine.

[0009] Preferably, the alkaline agent includes one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, and potassium bicarbonate.

[0010] Preferably, the humectant includes one or more of ethanol, ethylene glycol, glycerol, 1,4-butanediol, diethylene glycol, and triethylene glycol.

[0011] Preferably, the wetting agent is an acetylenic diol surfactant.

[0012] More preferably, the acetylenol surfactant is one of Surfynol 420, Surfynol 440, and Surfynol 465.

[0013] The second aspect of the present invention provides a method for preparing a whitening digital inkjet ink, comprising: first adding deionized water, then adding a discharge agent, an ink stabilizer, and an alkali agent in sequence, adding the next agent only after each agent has been completely dissolved, adding a wetting agent and a humectant after all the agents have been dissolved, stirring, and then filtering to obtain the whitening digital inkjet ink.

[0014] Preferably, the filtration pressure is no greater than 0.1 MPa.

[0015] Preferably, the filtration is a multiple filtration process, and the diameter of the filter element is 0.2-0.9 μm.

[0016] The third aspect of the present invention provides a printing process, comprising the following steps: printing a white digital inkjet ink image on a fabric using an inkjet printing device, and drying the fabric at 120-170°C for 1-3 minutes after printing.

[0017] Preferably, the drying equipment is the equipment described in the prior art CN202123078331.

[0018] Preferably, the inkjet printer printhead is selected from one of Epson i3200, S3200, Ricoh G6, Kyocera KJ4B, Starlight 1024, and Komei 1024.

[0019] Beneficial effects

[0020] (i) The ink prepared by using discharge agent, ink stabilizer, alkali agent, humectant, wetting agent and other raw materials in this invention can be used for digital inkjet printing. The preparation method is simple, the cost is low, and it is suitable for industrial scale-up production.

[0021] (II) The discharge inkjet ink preparation process and printing process provided by this invention produce no wastewater or waste gas. The printed finished products have a high white discharge rate and a soft hand feel, which has good social and economic benefits.

[0022] (III) In this invention, the inventors discovered that the combination of an ink stabilizer containing carbamate and a stripping agent containing sodium pyrophosphate can significantly improve the stability of the ink. After the finished product is stored at 45°C for more than 120 days, the whitening effect of the ink does not significantly decrease.

[0023] (iv) In this invention, it was found that when the stripping agent includes sodium benzylaminobenzenesulfonate, the stripping effect does not increase significantly with the addition of 4% sodium benzylaminobenzenesulfonate. The stripping effect of thiourea dioxide gradually increases with the addition of 2%, but the solubility of thiourea dioxide is limited. If the amount exceeds 2%, it cannot dissolve and solid precipitation will affect printing. Therefore, the optimal addition amount is 2%.

[0024] (V) In this invention, acetylenic diol surfactant is used as a wetting agent. Acetylene diol surfactant has multiple functions such as wetting, defoaming, improving the dispersibility of the system, and improving flow and leveling. It can quickly and effectively reduce the surface tension of the system and has low foaming. Compared with traditional surfactants, it has lower water sensitivity and recoatability, can provide a wider defoaming temperature range, and its solubility in water is limited. Therefore, adding a small amount can obtain a satisfactory defoaming effect and has a good effect on controlling microbubbles. Its application in this ink can make this ink have better stability and whitening effect. Detailed Implementation

[0025] Example 1

[0026] The first aspect of this embodiment provides a whitening digital inkjet ink, the raw materials of which are, by mass percentage: sodium benzylaminobenzenesulfonate 2.5%, sodium pyrophosphate 1%, carbazide 2%, ascorbic acid 3%, sodium bicarbonate 2.5%, glycerol 25%, acetylacetonate surfactant Surfynol 465 1%, and deionized water 63%.

[0027] The second aspect of this embodiment provides a method for preparing a whitening digital inkjet ink, specifically: first, deionized water is added, then a discharge agent, an ink stabilizer, and an alkali are added sequentially, with each agent completely dissolved before adding the next. After all the agents are dissolved, a wetting agent and a humectant are added and stirred. Then, the ink is filtered sequentially using a 0.8μm diameter nylon filter, a 0.45μm diameter nylon filter, and a 0.22μm diameter PES (polyethersulfone resin) filter, with the filtration pressure not exceeding 0.1MPa, thus obtaining the whitening digital inkjet ink.

[0028] The third aspect of this embodiment provides a printing process in which a white digital inkjet ink image is printed on a black background fabric using a Kyocera KJ4B printing device. The printhead is an Epson i3200. After printing, the image is dried at 150°C for 1 minute in a drying device. The drying device is the one described in the prior art CN202123078331.

[0029] Example 2

[0030] The first aspect of this embodiment provides a whitening digital inkjet ink, the raw materials of which are, by mass percentage: sodium benzylaminobenzenesulfonate 4%, sodium pyrophosphate 1%, carbazide 2%, ascorbic acid 0.5%, sodium bicarbonate 2.5%, glycerol 25%, acetylacetonate surfactant Surfynol 465 1%, and deionized water 64%.

[0031] The second aspect of this embodiment provides a method for preparing a whitening digital inkjet ink, specifically: first, deionized water is added, then a discharge agent, an ink stabilizer, and an alkali are added sequentially, with each agent completely dissolved before adding the next. After all the agents are dissolved, a wetting agent and a humectant are added and stirred. Then, the ink is filtered sequentially using a 0.8μm diameter nylon filter, a 0.45μm diameter nylon filter, and a 0.22μm diameter PES (polyethersulfone resin) filter, with the filtration pressure not exceeding 0.1MPa, thus obtaining the whitening digital inkjet ink.

[0032] The third aspect of this embodiment provides a printing process in which a white digital inkjet ink image is printed on a black background fabric using a Kyocera KJ4B printing device. The printhead is an Epson i3200. After printing, the image is dried at 150°C for 1 minute in a drying device. The drying device is the one described in the prior art CN202123078331.

[0033] Example 3

[0034] The first aspect of this embodiment provides a whitening digital inkjet ink, the raw materials of which are, by mass percentage: 5% sodium benzylaminobenzenesulfonate, 1% sodium pyrophosphate, 2% carbazide, 3% ascorbic acid, 2.5% sodium bicarbonate, 25% glycerol, 1% acetylacetonate surfactant Surfynol 465, and 63% deionized water.

[0035] The second aspect of this embodiment provides a method for preparing a whitening digital inkjet ink, specifically: first, deionized water is added, then a discharge agent, an ink stabilizer, and an alkali are added sequentially, with each agent completely dissolved before adding the next. After all the agents are dissolved, a wetting agent and a humectant are added and stirred. Then, the ink is filtered sequentially using a 0.8μm diameter nylon filter, a 0.45μm diameter nylon filter, and a 0.22μm diameter PES (polyethersulfone resin) filter, with the filtration pressure not exceeding 0.1MPa, thus obtaining the whitening digital inkjet ink.

[0036] The third aspect of this embodiment provides a printing process in which a white digital inkjet ink image is printed on a black background fabric using a Kyocera KJ4B printing device. The printhead is an Epson i3200. After printing, the image is dried at 150°C for 1 minute in a drying device. The drying device is the one described in the prior art CN202123078331.

[0037] Example 4

[0038] The first aspect of this embodiment provides a whitening digital inkjet ink, the raw materials of which are, by mass percentage: 1.3% thiourea dioxide, 1% sodium pyrophosphate, 2% carbazide, 3% salicylic acid, 1% sodium hydroxide, 23% triethylene glycol, 0.6% acetylacetonate surfactant Surfynol 440, and 68.1% deionized water.

[0039] The second aspect of this embodiment provides a method for preparing a whitening digital inkjet ink, specifically: first, deionized water is added, then a discharge agent, an ink stabilizer, and an alkali are added sequentially, with each agent completely dissolved before adding the next. After all the agents are dissolved, a wetting agent and a humectant are added and stirred. Then, the ink is filtered sequentially using a 0.8μm diameter nylon filter, a 0.45μm diameter nylon filter, and a 0.22μm diameter PES (polyethersulfone resin) filter, with the filtration pressure not exceeding 0.1MPa, thus obtaining the whitening digital inkjet ink.

[0040] The third aspect of this embodiment provides a printing process in which a white digital inkjet ink image is printed on a black background fabric using a Kyocera KJ4B printing device. The printhead is an Epson i3200. After printing, the image is dried at 150°C for 1 minute in a drying device. The drying device is the one described in the prior art CN202123078331.

[0041] Example 5

[0042] The first aspect of this embodiment provides a whitening digital inkjet ink, the raw materials of which are, by mass percentage: 1.5% thiourea dioxide, 2% sodium pyrophosphate, 2% carbazide, 3% salicylic acid, 1.5% potassium hydroxide, 28% diethylene glycol, 1% Surfynol 420 surfactant, and 61% deionized water.

[0043] The second aspect of this embodiment provides a method for preparing a whitening digital inkjet ink, specifically: first, deionized water is added, then a discharge agent, an ink stabilizer, and an alkali are added sequentially, with each agent completely dissolved before adding the next. After all the agents are dissolved, a wetting agent and a humectant are added and stirred. Then, the ink is filtered sequentially using a 0.8μm diameter nylon filter, a 0.45μm diameter nylon filter, and a 0.22μm diameter PES (polyethersulfone resin) filter, with the filtration pressure not exceeding 0.1MPa, thus obtaining the whitening digital inkjet ink.

[0044] The third aspect of this embodiment provides a printing process in which a white digital inkjet ink image is printed on a black background fabric using a Kyocera KJ4B printing device. The printhead is an Epson i3200. After printing, the image is dried at 150°C for 1 minute in a drying device. The drying device is the one described in the prior art CN202123078331.

[0045] Example 6

[0046] The first aspect of this embodiment provides a whitening digital inkjet ink, the raw materials of which are, by mass percentage: 2% thiourea dioxide, 1% sodium pyrophosphate, 2% carbazide, 3% salicylic acid, 1.5% potassium hydroxide, 28% diethylene glycol, 1% acetylacetonate surfactant Surfynol 420, and 61.5% deionized water.

[0047] The second aspect of this embodiment provides a method for preparing a whitening digital inkjet ink, specifically: first, deionized water is added, then a discharge agent, an ink stabilizer, and an alkali are added sequentially, with each agent completely dissolved before adding the next. After all the agents are dissolved, a wetting agent and a humectant are added and stirred. Then, the ink is filtered sequentially using a 0.8μm diameter nylon filter, a 0.45μm diameter nylon filter, and a 0.22μm diameter PES (polyethersulfone resin) filter, with the filtration pressure not exceeding 0.1MPa, thus obtaining the whitening digital inkjet ink.

[0048] The third aspect of this embodiment provides a printing process in which a white digital inkjet ink image is printed on a black background fabric using a Kyocera KJ4B printing device. The printhead is an Epson i3200. After printing, the image is dried at 150°C for 1 minute in a drying device. The drying device is the one described in the prior art CN202123078331.

[0049] Comparative Example 1

[0050] The specific implementation method of this comparative example is the same as that of Example 1, except that: carbazide is replaced with an equal amount of the analog toluenesulfonyl hydrazine, and ascorbic acid is replaced with an equal amount of glucose.

[0051] Comparative Example 2

[0052] The specific implementation method of this comparative example is the same as that of Example 2, except that: carbazide is replaced with an equal amount of the analog toluenesulfonyl hydrazine, and ascorbic acid is replaced with an equal amount of glucose.

[0053] Comparative Example 3

[0054] The specific implementation method of this comparative example is the same as that of Example 3, except that: carbazide is replaced with an equal amount of the analog toluenesulfonyl hydrazine, and ascorbic acid is replaced with an equal amount of glucose.

[0055] Comparative Example 4

[0056] The specific implementation method of this comparative example is the same as that of Example 4, except that: the carbazide is replaced with an equal amount of the analog toluenesulfonyl hydrazine, and the salicylic acid is replaced with an equal amount of benzoic acid.

[0057] Comparative Example 5

[0058] The specific implementation method of this comparative example is the same as that of Example 5, except that: the carbazide is replaced with an equal amount of the analog toluenesulfonyl hydrazine, and the salicylic acid is replaced with an equal amount of benzoic acid.

[0059] Comparative Example 6

[0060] The specific implementation method of this comparative example is the same as that of Example 6, except that: the carbazide is replaced with an equal amount of the analog toluenesulfonyl hydrazine, and the salicylic acid is replaced with an equal amount of benzoic acid.

[0061] Performance Evaluation

[0062] Test subjects: Examples 1-6, Comparative Examples 1-6, ink parameters are shown in Table 1, and the test temperature is 30℃.

[0063] Table 1

[0064]

[0065] Whitening test: The whitening performance and stability of the ink are shown in Table 2. The ink prepared above was printed on a black background fabric using a Kyocera KJ4B printer. Only the whiteness of the printed ink area was calibrated by drying at 150°C for 1 minute to determine the whitening effect.

[0066] Table 2

[0067]

[0068]

[0069] Whiteness testing is referenced in GB / T 8424.2-2001. Textiles—Tests for colour fastness—Instrumental assessment of relative whiteness. 1 Scope 1.1 GB / T 8424.2 specifies a method for quantitatively assessing the whiteness and palatability index of textiles, including fluorescent materials. The whiteness measured by this method is displayed as a whiteness reading of a textile. The palatability index is displayed as a shift reading of reddish or greenish hues other than zero at a neutral hue of 466 nm. The formulas for calculating whiteness and palatability index are recommended by the CIE (International Commission on Illumination).

Claims

1. A whitening digital inkjet ink, characterized in that: The raw materials for preparation, by mass percentage, include: 0.5-10% discharge agent, 1-10% ink stabilizer, 0.5-5% alkali agent, 5-50% humectant, 0.2-5% wetting agent, and the balance being deionized water; The stripping agent is sodium pyrophosphate and other stripping agents; The other stripping agents are one or more of thiourea dioxide, sodium dithionite, sodium sulfite, sodium thiosulfate, and sodium pyrophosphate. The ink stabilizer is a carbamate and other stabilizers; The other stabilizers are one or more of glucose, ascorbic acid, salicylic acid, benzoic acid, and toluenesulfonyl hydrazine; The alkaline agent includes one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, and potassium bicarbonate. The humectant includes one or more of ethanol, ethylene glycol, propanol, 1,4-butanediol, diethylene glycol, triethylene glycol, and glycerol. The wetting agent is an acetylenic diol surfactant.

2. A method for preparing the white-coated digital inkjet ink according to claim 1, characterized in that: Includes the following steps: First, add deionized water, then add discharge agent, ink stabilizer, and alkali agent in sequence. After each agent is completely dissolved, add the next one. After all the agents are dissolved, add wetting agent and humectant and stir. Then, filter through multiple stages to obtain the discharge digital inkjet ink.

3. A printing process comprising the white-discharge digital inkjet ink of claim 1, characterized in that, The process includes the following steps: printing a white digital inkjet ink image onto the fabric using an inkjet printer, and then drying it in a drying equipment at 120-170℃ for 1-3 minutes after printing.

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