Acidic ink-jet digital printing ink, and preparation method and application thereof

Abstract

The invention discloses acid ink-jet digital printing ink as well as a preparation method and application thereof. The ink mainly comprises dye, polyethylene glycol, ethylene glycol, glycerol, sodium dodecyl benzene sulfonate, 2-fluoroethanol, isothiazolinone, a modified color fixing agent and water. The modified color fixing agent is prepared from alkanolamide, a surfactant, a grafting agent, a catalyst, a modifier and other raw materials. The ink has excellent color fastness and stability, is suitable for waterless digital printing of polyester and nylon fabrics, solves the problems of poor wet fastness and low stability of traditional acid ink, and has the advantages of high efficiency and bright color.

Description

Technical Field

[0001] The present invention relates to the technical field of inks, and in particular to an acidic inkjet digital printing ink, a preparation method and an application thereof. Background Art

[0002] With the rapid development of digital technology, inkjet printing technology has been widely used in the textile printing and dyeing industry due to its environmental protection, high efficiency and flexibility. Especially in the field of acid inkjet digital printing, it has become an important development direction of the textile printing and dyeing industry because it can provide bright colors and good color fastness. Acid inkjet digital printing ink is mainly used for coloring and printing of fabrics such as wool, silk and nylon. Its water-soluble dye molecular structure contains groups such as sulfonic acid groups, which can be combined with protein fibers and polyurethane fibers through ionic bonds, hydrogen bonds and other methods.

[0003] However, traditional acidic inkjet digital printing inks have some limitations in practical applications. First, due to the relatively poor wet fastness, printed textiles are prone to fade during washing, affecting the appearance and service life of the product. Secondly, in order to improve the color fixation rate, inorganic alkaline color fixatives such as sodium bicarbonate are usually required. These color fixatives not only increase the content of inorganic salts in the ink, reduce the stability of the ink, but also increase the corrosiveness of the ink, posing potential risks to equipment and operators.

[0004] CN105419484A discloses an inkjet printing acid ink suitable for industrial nozzles and a preparation method thereof, including acid dyes, solubilizers, surfactants, organic solvents, wetting agents and water, etc. The preparation method can effectively improve the solubility of acid dyes in ink and improve the fluidity and jettability of ink in ink paths and nozzles, and selects a surfactant combination with a low contact angle and low dynamic surface tension, which can give the ink better leveling and wettability, while the combined effect of solubilizers, surfactants and wetting agents makes the ink have good versatility and smooth performance. However, the color fastness of the inkjet printing acid ink prepared by this method is poor, and it is difficult to meet market requirements.

[0005] CN111472183A discloses an acid dye ink composition and a method for preparing the same, comprising: 1 to 15 parts by weight of an acid dye, 0.1 to 10 parts by weight of a penetrant, 20 to 50 parts by weight of a solubilizing, moisturizing and viscosity adjusting agent, 0.1 to 0.5 parts by weight of a pH controlling agent, 1 to 5 parts by weight of a functional auxiliary agent, and 25 to 85 parts by weight of water. The method for preparing the composition comprises: (1) providing raw materials: 1 to 15 parts by weight of an acid dye, 0.1 to 10 parts by weight of a penetrant, 20 to 50 parts by weight of a solubilizing, moisturizing and viscosity adjusting agent, 0.1 to 0.5 parts by weight of a pH controlling agent, 1 to 5 parts by weight of a functional auxiliary agent, and 25 to 85 parts by weight of water; (2) mixing the raw materials of (1) and stirring them at 40 to 80°C for 0.5 to 4 hours; (3) cooling the mixture of (2) to room temperature and filtering the mixture through microporous filters of decreasing pore size. Although the acid dye ink composition prepared by the method has excellent storage stability and can provide antistatic or moisture absorption and perspiration functions for printed fabrics, the acid dye ink prepared by the invention has poor color fixation effect and is easy to fade, which affects the appearance. Summary of the invention

[0006] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to improve the color fixing effect of acid inkjet digital printing ink, reduce the fading, discoloration or staining of the ink, and improve the storage stability of the ink.

[0007] To achieve the above object, the present invention provides an acidic inkjet digital printing ink, comprising the following components in parts by weight: 10-20 parts of dye, 1-5 parts of polyethylene glycol, 1-8 parts of ethylene glycol, 15-20 parts of propylene glycol, 0.1-1 parts of sodium dodecylbenzene sulfonate, 0.01-0.04 parts of 2-fluoroethanol, 0.1-1 parts of isothiazolinone, 1-5 parts of modified color fixing agent and 40-60 parts of water; wherein the preparation method of the modified color fixing agent comprises the following steps:

[0008] S1, mixing an alkanolamide with an ethanol aqueous solution to obtain an alkanolamide solution, and separately mixing a surfactant with water to obtain an aqueous surfactant solution;

[0009] S2, dissolving the grafting agent and the catalyst in the alkanolamide solution prepared in step S1, stirring at 100-130° C. for 10-35 min, adding the modifier, stirring at 65-80° C. for 20-40 min, adding the acetic acid aqueous solution, stirring at 65-80° C. for 50-80 min, adding the surfactant aqueous solution prepared in step S1, stirring at 45-60° C. for 85-100 min, and cooling to room temperature to obtain the modified color fixing agent.

[0010] Preferably, the modifier is any one of [bis(trimethylsilyl)hydrazine]-oxymethane, 1,1,1-trimethylsilylamine, and heptamethyldisilazane.

[0011] More preferably, the modifier is [bis(trimethylsilyl)hydrazide]-oxymethane.

[0012] Preferably, the mass ratio of the alkanolamide to ethanol is 1:(5-8).

[0013] Preferably, the mass ratio of the grafting agent to the modifier is (25-40):(5-15).

[0014] Preferably, the concentration of the acetic acid aqueous solution is 40-50 wt %.

[0015] Preferably, the stirring speed is 100-400 rpm.

[0016] Preferably, the surfactant is any one of nonylphenol polyoxyethylene ether, ethylene glycol dimethyl ether, and sorbitol.

[0017] The invention also discloses a method for preparing the acidic inkjet digital printing ink.

[0018] A method for preparing an acidic inkjet digital printing ink comprises the following steps, measured in parts by weight:

[0019] Step 1: Mix 30-45 parts of dye and 60-90 parts of water to make a slurry, and sand grind the slurry to particles of 0.01-0.3 μm to obtain a dye grinding paste;

[0020] Step 2: Add 2-8 parts of aminotriacetic acid and 30-50 parts of water to 50-70 parts of the dye grinding paste prepared in the above step 1, stir at a speed of 150-200 rpm for 3-4 hours, filter through a 0.2-0.5 μm filter membrane, and then adjust the pH to 3-5 to precipitate the dye, filter the precipitated dye, and filter under a pressure of 10-15 MPa for 4-5 hours to obtain a mixed dye;

[0021] Step 3: dissolve 10-20 parts of the mixed dye prepared in step 2 above in 40-60 parts of water, add 1-5 parts of polyethylene glycol, 1-8 parts of ethylene glycol, 15-20 parts of propylene glycol, 0.1-1 parts of sodium dodecylbenzene sulfonate, 0.01-0.04 parts of 2-fluoroethanol, 0.1-1 parts of isothiazolinone, and 1-5 parts of modified color fixing agent in sequence, stir at 150-200 rpm for 1-2 hours, adjust the pH to 8-9 with citric acid and ethanolamine, filter with a 1-3 μm filter membrane, and finally filter with a 0.2-0.5 μm filter membrane to obtain an acidic inkjet digital printing ink.

[0022] The invention discloses an acid inkjet digital printing ink for use in polyester and nylon fabric printing and textile printing.

[0023] Technical conception:

[0024] Acid dye ink is a water-soluble dye, which is roughly composed of high-purity acid dye, co-solvent and deionized water. The dye molecular structure contains sulfonic acid groups, which can be combined with protein fibers and polyurethane fibers by ionic bonds, hydrogen bonds and other methods. Therefore, it is mainly used for coloring and printing fabrics such as wool, silk and nylon. Compared with reactive dyes, the color of fabrics printed with acid ink is brighter, but the wet fastness of printed textiles is relatively poor. Therefore, it is considered to use modified fixing agents to improve the fixing rate of acid dye ink. Modified fixing agents can catalyze the covalent cross-linking of reactive dyes with fibers, thereby greatly improving the fixing rate of ink. This is especially important for cotton and rayon materials, which can avoid the use of inorganic alkaline fixing agents such as sodium bicarbonate, reduce the content of inorganic salts in the ink, improve the stability under dispersion, and reduce the corrosiveness of the ink.

[0025] The preparation idea of ​​modified color fixing agent is:

[0026] Alkanolamide is mixed with ethanol to form a stable solution, which provides a uniform reaction medium for subsequent reactions. Under heating conditions, the grafting agent forms a uniform premix in the catalyst and alkanolamide solution. Adding a modifier helps to improve the bonding performance of the modified color fixing agent and the fiber. At the same time, adding acetic acid aqueous solution and adjusting the pH value can optimize the color fixing conditions.

[0027] In this recipe, the ingredients and their functions are as follows:

[0028] [Bis(trimethylsilyl)hydrazide]-oxymethane as a modifier contains a silanol group and an isocyanate group, which reacts with the grafting agent to form a carbamate bond, thereby improving the color friction fastness and hydrolysis fastness of the ink on the fabric, and further improving the bonding performance of the modified color fixing agent and the fiber.

[0029] 2,2'-Diallyl 4,4'-bisphenol is used as a grafting agent, providing bisphenol groups and also containing double bonds, which has high reactivity, participates in the polymerization reaction, forms a cross-linked structure, and enhances the bonding force between the fixing agent and the fiber.

[0030] Beneficial effects of the present invention:

[0031] 1. Compared with the prior art, the present invention improves the color fastness to friction and hydrolysis of the ink on the fabric by applying a modified color fixing agent to the ink. The color fixing agent contains a silanol group and an isocyanate group that can form a stable silicon-oxygen bond with the fiber. The isocyanate group can react with the hydroxyl group in the grafting agent to form a carbamate bond. The use of this modified color fixing agent significantly improves the soaping color fastness, friction color fastness and perspiration color fastness of the printed textiles compared to the traditional color fixing agent, so that the acid inkjet digital printing ink of the present invention has obvious advantages in color fixing performance.

[0032] 2. Compared with the prior art, the present invention avoids the use of inorganic alkaline color fixing agents such as sodium bicarbonate, thereby reducing the content of inorganic salts in the ink, improving the dispersion stability of the ink, and reducing the corrosiveness of the ink. This improvement not only reduces the impact on the environment, but also reduces production costs and improves economic benefits. At the same time, due to the high efficiency of the modified color fixing agent, the amount of color fixing agent used can be reduced, further reducing costs while maintaining or improving product quality. DETAILED DESCRIPTION

[0033] Parameters for specific chemical substances used, sources.

[0034] Polyethylene glycol, model: PEG-200, Dow Chemical.

[0035] Nonylphenol polyoxyethylene ether, model: NP-10, Hamm, Germany.

[0036] Commercially available color fixing agent, model: GR-3006, Ningbo Yinzhou Green Detergent Factory.

[0037] [bis(trimethylsilyl)hydrazinylidene]-oxomethane, CAS No.: 107257-55-6.

[0038]

[0039] Example 1

[0040] A method for preparing an acidic inkjet digital printing ink comprises the following steps:

[0041] Step 1: Mix 30 kg of CI Acid Blue 40 and 70 kg of water to form a slurry, and grind the slurry to a particle size of 0.1 μm to obtain a dye grinding paste;

[0042] Step 2: Add 5kg of aminotriacetic acid and 35kg of water to 60kg of the dye grinding paste prepared in the above step 1, stir at 200rpm for 4h, filter through a 0.45μm filter membrane, and then adjust the pH to 4 with 35wt% citric acid and 45wt% ethanolamine to precipitate the dye, filter the precipitated dye with a 0.5μm filter membrane, and filter at a pressure of 15MPa for 5h to obtain the dye;

[0043] Step 3: dissolve 15 kg of the dye prepared in step 2 above in 55.98 kg of water, add 3 kg of polyethylene glycol, 5 kg of ethylene glycol, 20 kg of propylene glycol, 0.5 kg of sodium dodecylbenzene sulfonate, 0.02 kg of 2-fluoroethanol, 0.5 kg of isothiazolinone, and 2 kg of modified color fixing agent in sequence, stir at 200 rpm for 2 h, adjust the pH to 8 with 35 wt % of citric acid and 45 wt % of ethanolamine, filter with a 3 μm filter membrane, and finally filter with a 0.5 μm filter membrane to obtain an acidic inkjet digital printing ink.

[0044] The preparation method of the modified color fixing agent comprises the following steps:

[0045] S1, 1kg of lauroyl diethanolamine and 6kg of 30wt% ethanol aqueous solution were mixed at 200rpm for 10min to obtain a lauroyl diethanolamine aqueous solution; and 1kg of nonylphenol polyoxyethylene ether and 5.5kg of water were mixed at 200rpm for 10min to obtain a nonylphenol polyoxyethylene ether aqueous solution;

[0046] S2, 30kg of 2,2'-diallyl 4,4'-bisphenol and 2kg of dibutyltin oxide were dissolved in the lauroyl diethanolamine aqueous solution prepared in step S1, stirred at 120°C at 200rpm for 20min, then 10kg of [bis(trimethylsilyl)hydrazide]-oxomethane was added, stirred at 80°C for 35min, then 3L of 45wt% acetic acid aqueous solution was added, stirred at 65°C at 200rpm for 55min, the nonylphenol polyoxyethylene ether aqueous solution prepared in step S1 was added, then stirred at 60°C for 95min, and finally cooled to 25°C to obtain a modified color fixing agent.

[0047] Example 2

[0048] The difference between Example 2 of the present application and Example 1 is that the [bis(trimethylsilyl)hydrazine]-oxymethane in Example 1 is replaced by tris(trimethylsilyl)amine.

[0049] Example 3

[0050] The difference between Example 3 of the present application and Example 1 is that the [bis(trimethylsilyl)hydrazine]-oxymethane in Example 1 is replaced by heptamethyldisilazane.

[0051] Comparative Example 1

[0052] The difference between Comparative Example 1 of the present application and Example 1 is that the 2,2'-diallyl 4,4'-bisphenol in Example 1 is replaced by bisphenol S.

[0053] Comparative Example 2

[0054] The difference between Comparative Example 2 of the present application and Example 1 is that the [bis(trimethylsilyl)hydrazine]-oxymethane in Example 1 is replaced by hexamethyldisilazane.

[0055] Comparative Example 3

[0056] The difference between Comparative Example 3 of the present application and Example 1 is that the modified color fixing agent added in step 3 of Example 1 is replaced by a commercially available color fixing agent.

[0057] Test Example 1

[0058] Color fastness to washing with soap: Determined in accordance with GB / T 3921-2008 "Textiles - Tests for Color Fastness - Color Fastness to Washing with Soap";

[0059] Color fastness to rubbing: Determined in accordance with GB / T 3920-2008 "Textiles - Tests for Color Fastness - Color Fastness to Rubbing";

[0060] Perspiration fastness: Tested according to GB / T 3922-2013 "Textiles - Tests for colour fastness - Colour fastness to perspiration". See Table 1 for test results:

[0061] Table 1 Fixing performance test results

[0062]

[0063] Test Example 2

[0064] The acidic inkjet digital printing ink prepared in Examples 1-3 and Comparative Examples 1-3 was printed on the surface of the textile by a digital printer, and was first pre-baked at 100°C for 1 min, and then baked at 150°C for 2 min to crosslink and solidify the ink to form an inkjet printing pattern. The ink was stored at 0°C and 60°C for 24 h, and the storage stability was tested three times. The test results are shown in Table 2:

[0065] Table 2 Storage stability

[0066]

[0067] By observing the color fixing performance test results in Table 1, it can be seen that the color fixing effect and storage stability of the acidic inkjet digital printing ink prepared in Example 1 are the best.

[0068] Compared with the test results in Examples 1-3 and Comparative Example 2, it can be found that the storage stability, soaping color fastness, rubbing color fastness and perspiration color fastness grades in Example 1 are the best. The possible reason is that different modifiers are used. The modifier is a silane coupling agent compound containing silanol groups, which can form stable silicon oxygen bonds with the fiber, thereby improving the bonding performance of the color fixing agent to the fiber. In addition to containing silanol groups, the modifier in Example 1 also contains isocyanate groups, which can react with the hydroxyl functional groups contained in the grafting agent to form carbamate bonds. Carbamate bonds are formed on the hard segment, which helps to improve the mechanical properties of digital printing inks. At the same time, the presence of carbamate bonds helps to improve the color rubbing fastness and hydrolysis fastness of the ink on the fabric. The modifiers in Examples 2-3 and Comparative Example 2 do not contain isocyanate groups, so the prepared modified color fixing agent does not contain carbamate bonds, so it shows worse color fixing effect and mechanical properties.

[0069] Compared with the test results of Example 1 and Comparative Example 1, it can be found that the storage stability, soaping color fastness, rubbing color fastness and perspiration color fastness grades in Example 1 are the best. The possible reason is that different grafting agents are used. As one of the raw materials for preparing the modified color fixing agent, the grafting agent can provide a bisphenol group. By comparing the grafting agents in Example 1 and Comparative Example 1, it is found that in addition to the bisphenol group, the grafting agent in Example 1 also contains a diallyl double bond in the molecular structure of 2,2'-diallyl 4,4'-bisphenol. This double bond has a high reactivity. In the preparation process of the color fixing agent, these double bonds can participate in the polymerization reaction to form more cross-linked structures. This cross-linked structure can enhance the bonding force between the color fixing agent and the fiber, thereby improving the color fixing effect. At the same time, compounds containing double bonds usually have good thermal stability, which improves the storage stability of the ink. In the preparation and application process of the color fixing agent, this stability helps to maintain the performance of the color fixing agent, especially in the high-temperature curing process, which can reduce the thermal decomposition of the color fixing agent, thereby improving the color fixing effect. Therefore, the color fixing effect of the acidic inkjet digital printing ink prepared in Example 1 is the best.

[0070] The color fixing agent in Example 1 is a modified color fixing agent, while the color fixing agent in Comparative Example 3 is a commercially available color fixing agent. In comparison, Example 1 has a better color fixing effect than Comparative Example 3. The possible reason is that the modified color fixing agent in Example 1 is obtained through a specific chemical reaction and process control, and the modified color fixing agent can react with the sulfonate in the dye to form a complex, which increases the interaction between the modified color fixing agent and the dye. Therefore, the acidic digital printing ink prepared in Example 1 exhibits better color fixing effect and storage stability.

Claims

1. An acidic inkjet digital printing ink, characterized in that: The invention comprises the following components in parts by weight: 10-20 parts of dye, 1-5 parts of polyethylene glycol, 1-8 parts of ethylene glycol, 15-20 parts of propylene glycol, 0.1-1 parts of sodium dodecylbenzene sulfonate, 0.01-0.04 parts of 2-fluoroethanol, 0.1-1 parts of isothiazolinone, 1-5 parts of modified color fixing agent and 40-60 parts of water; wherein the preparation method of the modified color fixing agent comprises the following steps: S1, mixing an alkanolamide with an ethanol aqueous solution to obtain an alkanolamide solution; and separately mixing a surfactant with water to obtain an aqueous surfactant solution; S2, dissolving the grafting agent and the catalyst in the alkanolamide solution prepared in step S1, stirring at 100-130° C. for 10-35 min, adding the modifier, stirring at 65-80° C. for 20-40 min, adding the acetic acid aqueous solution, stirring at 65-80° C. for 50-80 min, adding the surfactant aqueous solution prepared in step S1, stirring at 45-60° C. for 85-100 min, and cooling to room temperature to obtain the modified color fixing agent.

2. The acidic inkjet digital printing ink according to claim 1, characterized in that: The modifier is any one of [bis(trimethylsilyl)hydrazine]-oxymethane, 1,1,1-trimethylsilylamine and heptamethyldisilazane.

3. The acidic inkjet digital printing ink according to claim 2, characterized in that: The modifier is [bis(trimethylsilyl)hydrazide]-oxymethane.

4. The acidic inkjet digital printing ink according to claim 1, characterized in that: The mass ratio of the alkanolamide to ethanol is 1:(5-8).

5. The acidic inkjet digital printing ink according to claim 1, characterized in that: The mass ratio of the grafting agent to the modifier is (25-40):(5-15).

6. The acidic inkjet digital printing ink according to claim 1, characterized in that: The concentration of the acetic acid aqueous solution is 40-50 wt %.

7. The acidic inkjet digital printing ink according to claim 1, characterized in that: The stirring speed is 100-400 rpm.

8. The acidic inkjet digital printing ink according to claim 1, characterized in that: The surfactant is any one of nonylphenol polyoxyethylene ether, ethylene glycol dimethyl ether and sorbitol.

9. The method for preparing the acidic inkjet digital printing ink according to any one of claims 1 to 8, characterized in that: The method comprises the following steps, in parts by weight: Step 1: Mix 30-45 parts of dye and 60-90 parts of water to make a slurry, and sand grind the slurry to particles of 0.01-0.3 μm to obtain a dye grinding paste; Step 2: Add 2-8 parts of aminotriacetic acid and 30-50 parts of water to 50-70 parts of the dye grinding paste prepared in the above step 1, stir at a speed of 150-200 rpm for 3-4 hours, filter through a 0.2-0.5 μm filter membrane, and then adjust the pH to 3-5 to precipitate the dye, filter the precipitated dye, and filter under a pressure of 10-15 MPa for 4-5 hours to obtain a mixed dye; Step 3: dissolve 10-20 parts of the mixed dye prepared in step 2 above in 40-60 parts of water, add 1-5 parts of polyethylene glycol, 1-8 parts of ethylene glycol, 15-20 parts of propylene glycol, 0.1-1 parts of sodium dodecylbenzene sulfonate, 0.01-0.04 parts of 2-fluoroethanol, 0.1-1 parts of isothiazolinone, and 1-5 parts of modified color fixing agent in sequence, stir at 150-200 rpm for 1-2 hours, adjust the pH to 8-9 with citric acid and ethanolamine, filter with a 1-3 μm filter membrane, and finally filter with a 0.2-0.5 μm filter membrane to obtain an acidic inkjet digital printing ink.

10. Use of the acidic inkjet digital printing ink according to any one of claims 1 to 8 in polyester and nylon fabric printing and textile printing.

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