An acidic digital printing ground and a preparation method and application thereof

Abstract

This invention discloses an acidic digital printing base paste and its preparation method. The printing base paste is composed of the following components in weight percentages: 1.5-3% thickener, 2-5% co-solvent, 2-5% hygroscopic agent, 1-1.6% malic acid, 0.5-0.8% chitosan quaternary ammonium salt, 0.5-2.5% sodium chloride, 1-3% ammonium sulfate, and the balance being water. The thickener is composed of corn cellulose gum, polyacrylic acid, and sodium montmorillonite / polypropylene amide composite, wherein, by weight, the ratio of corn cellulose gum: polyacrylic acid: sodium montmorillonite / polypropylene amide composite is 1:(1.2-2):(1-2). The acidic digital printing base paste of this invention, by combining the thickener with the co-solvent, hygroscopic agent, retarding agent sodium chloride, and acidic auxiliary agent ammonium sulfate, improves the K / S value and penetration rate of the printing paste, and enhances water retention, color fastness, antibacterial properties, and wrinkle resistance, making it suitable for use in nylon printing processes.

Description

Technical Field

[0001] This invention relates to the field of digital printing technology, and in particular to an acidic digital printing base paste, its preparation method, and its application. Background Technology

[0002] Digital printing involves inputting patterns into a computer in digital form, editing and processing them using a computer-aided design (CAD) system, and then using a computer-controlled micro-piezoelectric inkjet nozzle to directly spray special dyes onto textiles or other media to create various high-precision patterns.

[0003] Acid dyes are generally aromatic sodium sulfonate salts containing sulfonic acid groups, hydroxyl groups, etc. A few are sodium carboxylate salts that ionize in water to form pigment acid anions, which can combine with amino or amide groups on fibers. Therefore, they can be used for dyeing and printing on protein fibers such as wool and silk, as well as polyamide synthetic fibers. Acid dyes have bright colors and good colorfastness. These dyes are mostly used in acidic solutions, hence the name acid dye dyeing. Since the main component of silk / wool / nylon fabrics is protein with free amino groups, acid digital printing is mainly used in the field of silk / wool / nylon PVC-coated fabrics. Acid digital printing paste is a chemical complex that acts as a medium for acid dyes to adhere to fibers during the digital printing process on silk / wool / nylon PVC-coated fabrics, aiding in the dyeing process. Digital printing paste has good absorption and retention properties for ink, promoting the combination of dyes with fibers under humid and hot conditions to achieve specific printing effects. Existing digital printing pastes have poor water retention, poor hand feel, poor brightness, and low color yield. Summary of the Invention

[0004] To address the shortcomings and deficiencies of the existing technology, the present invention aims to provide an acidic digital printing base paste, its preparation method, and its application.

[0005] To achieve its objective, the technical solution adopted by this invention is as follows:

[0006] An acidic digital printing base paste is composed of the following components in weight percentage: 1.5-3% thickener, 2-5% cosolvent, 2-5% hygroscopic agent, 1-1.5% malic acid, 0.5-0.8% chitosan quaternary ammonium salt, 0.5-2.5% sodium chloride, 1-3% ammonium sulfate, and the balance being water; the thickener is composed of corn cellulose gum, polyacrylic acid, and sodium montmorillonite / polypropylene amide complex, wherein the weight ratio of corn cellulose gum, polyacrylic acid, and sodium montmorillonite / polypropylene amide complex is corn cellulose gum: polyacrylic acid: sodium montmorillonite / polypropylene amide complex = 1:(1.2-2):(1-2).

[0007] The acidic digital printing base paste of this invention combines a thickener with a solubilizer, a humectant, malic acid, chitosan quaternary ammonium salt, a retarding agent sodium chloride, and an acidic auxiliary agent ammonium sulfate. This combination improves the K / S value and penetration rate of the printing paste, increases water retention, color fastness, wrinkle resistance, and antibacterial ability. The thickener is corn cellulose gum, which is extracted from corn fiber using an alkaline solution of hydrogen peroxide. It has a highly branched structure, and its glycosyl composition consists of D-xylose, L-arabinose, galactose, and glucuronic acid. This invention achieves a synergistic thickening effect by combining corn fiber adhesive with a thickening polymer, polyacrylic acid, and an organic-inorganic thickening complex, sodium-based montmorillonite / polypropylene amide, thereby improving the thickening effect of the corn fiber adhesive. The sodium chloride in this invention is a neutral electrolyte with a slow-dyeing effect, ensuring uniform dyeing of the fiber fabric without color variations. Furthermore, the concentration difference between sodium ions and the interior of the nylon fiber facilitates dye penetration, accelerates dye molecule mobility, and improves dye uptake. The acidic auxiliary agent, ammonium sulfate, releases ammonia gas during steaming of the nylon fabric, gradually increasing the acidity of the fiber's internal environment. This provides favorable dyeing conditions for acid dyes on the nylon fiber, ensuring a high dye uptake rate. Malic acid possesses anti-wrinkle and antibacterial properties and can also improve the colorfastness of natural dye printing. The applicant discovered that combining malic acid with macromolecular chitosan quaternary ammonium salt and polyacrylic acid can improve the wrinkle resistance of fabrics. Simultaneously, malic acid and chitosan quaternary ammonium salt can simultaneously promote the antibacterial and color-fixing abilities of the sizing agent on the fabric.

[0008] Preferably, the weight ratio of corn fiber gum, polyacrylic acid, and sodium montmorillonite / polypropylene amide composite is corn fiber gum: polyacrylic acid: sodium montmorillonite / polypropylene amide composite = 1:(1.5-1.8):(1.5-1.8). The inventors of this application have discovered that when the three components are mixed within this specific range, they exhibit superior performance (grades 4-5), K / S value, permeability, PVI, and electrolyte resistance.

[0009] More preferably, the weight ratio of corn fiber gum, polyacrylic acid, and sodium montmorillonite / polypropylene amide composite is corn fiber gum: polyacrylic acid: sodium montmorillonite / polypropylene amide composite = 1:1.6:1.6.

[0010] When the amounts of corn fiber adhesive, polyacrylic acid, and sodium montmorillonite / polypropylene amide composite meet the above conditions, the properties of the printing base paste are better.

[0011] Preferably, the weight ratio of malic acid to chitosan quaternary ammonium salt is 2:1. When malic acid and chitosan quaternary ammonium salt are combined in this ratio, they have a synergistic effect of antibacterial and color-fixing properties.

[0012] Preferably, the cosolvent is xylenesulfonic acid and / or diethylene glycol ether. The hygroscopic agent is glycerin.

[0013] The present invention also provides a method for preparing the aforementioned acidic digital printing base paste, comprising the following steps:

[0014] 1) Add the thickener to deionized water according to the weight ratio, mix well and stir, let stand for 8-18 hours to obtain the mixed paste;

[0015] 2) Add the cosolvent, humectant, sodium chloride, malic acid, chitosan quaternary ammonium salt, and ammonium sulfate to the water in step (1) and stir until uniform; to obtain the acidic digital printing base paste.

[0016] Another object of the present invention is to provide the application of the above-mentioned acidic digital printing base paste in nylon printing process.

[0017] In addition, the present invention also provides a digital printing process, which includes the following steps: pre-treating the fabric with the above-mentioned acidic digital printing base paste, digital printing, high-temperature steaming, color fixing, washing and drying.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: The acidic digital printing base paste of the present invention combines a thickener with a co-solvent, a hygroscopic agent, a dyeing retarder sodium chloride, malic acid, chitosan quaternary ammonium salt, and an acidic auxiliary agent ammonium sulfate, which can improve the K / S value and penetration rate of the printing paste, and improve the water retention rate, color fastness, wrinkle resistance and antibacterial effect. Detailed Implementation

[0019] To better illustrate the objectives, technical solutions, and advantages of this invention, the following embodiments are provided. Obviously, the following embodiments are only a part of the embodiments of this invention, and not all of them. It should be understood that the embodiments of this invention are only used to illustrate the technical effects of this invention, and are not intended to limit the scope of protection of this invention.

[0020] The preparation method of the sodium montmorillonite / polypropylene amide composite of the present invention is as follows: 25% sodium montmorillonite (by mass) of the total sodium montmorillonite / polypropylene amide composite is added to a 30% acrylamide aqueous solution and mixed evenly. The mixture is then stirred at 6000 rpm for 10 minutes, allowed to stand and soak for 12 hours, and then stirred at 5000 rpm for 5 minutes. After full hydration, the mixture is transferred to a reactor, and an initiator ammonium persulfate aqueous solution is added dropwise under stirring, so that the mass ratio of added ammonium persulfate to acrylamide is 1:350. After nitrogen deoxygenation, the mixture is placed in a 40°C water bath for constant temperature polymerization for 2 hours. After the reaction is completed, the product is vacuum dried at 50°C and pulverized to 200 mesh to obtain the sodium montmorillonite / polypropylene amide composite.

[0021] The extraction method of corn cellulose gum in this invention refers to the preparation of corn cellulose gum CFG1 in [Feng Huimin, Huang Qiang, Li Chao, Study on physicochemical properties and antioxidant activity of corn cellulose gum, Modern Food Science and Technology].

[0022] Example 1: An acidic digital printing base paste

[0023] An acidic digital printing base paste is composed of the following components in weight percentage: 2.5% thickener, 3% xylenesulfonic acid, 3% glycerol, 1.2% malic acid, 0.6% chitosan quaternary ammonium salt, 1% sodium chloride, 1.5% ammonium sulfate, and the balance being water.

[0024] The thickener comprises corn cellulose gum, polyacrylic acid, and sodium montmorillonite / polypropylene amide complex, wherein, by weight, corn cellulose gum: polyacrylic acid: sodium montmorillonite / polypropylene amide complex = 1:1.6:1.6.

[0025] Example 2: An acidic digital printing base paste

[0026] An acidic digital printing base paste is composed of the following components in weight percentage: 1.5% thickener, 2% diethylene glycol ether, 2% glycerin, 1% malic acid, 0.5% chitosan quaternary ammonium salt, 0.5% sodium chloride, 1% ammonium sulfate, and the balance being water.

[0027] The thickener comprises corn cellulose gum, polyacrylic acid, and sodium montmorillonite / polypropylene amide complex, wherein, by weight, corn cellulose gum: polyacrylic acid: sodium montmorillonite / polypropylene amide complex = 1:1.6:1.6.

[0028] Example 3: An acidic digital printing base paste

[0029] An acidic digital printing base paste is composed of the following components in weight percentage: 3% thickener, 3% xylenesulfonic acid, 2% diethylene glycol ether, 5% glycerol, 1.4% malic acid, 0.7% chitosan quaternary ammonium salt, 2.5% sodium chloride, 3% ammonium sulfate, and the balance being water.

[0030] The thickener comprises corn cellulose gum, polyacrylic acid, and sodium montmorillonite / polypropylene amide complex, wherein, by weight, corn cellulose gum: polyacrylic acid: sodium montmorillonite / polypropylene amide complex = 1:1.6:1.6.

[0031] Example 4: An acidic digital printing base paste

[0032] An acidic digital printing base paste is composed of the following components in weight percentage: 2.8% thickener, 3% diethylene glycol ether, 3% glycerol, 1.6% malic acid, 0.8% chitosan quaternary ammonium salt, 1% sodium chloride, 2% ammonium sulfate, and the balance water.

[0033] The thickener comprises corn cellulose gum, polyacrylic acid, and sodium montmorillonite / polypropylene amide complex, wherein, by weight, corn cellulose gum: polyacrylic acid: sodium montmorillonite / polypropylene amide complex = 1:1.6:1.6.

[0034] Comparative Example 1: An acidic digital printing base

[0035] An acidic digital printing base paste comprises the following components in weight percentage: 2.5% sodium alginate, 3% xylenesulfonic acid, 3% glycerol, 1% sodium chloride, 1.5% ammonium sulfate, and the balance being water.

[0036] Example 5: A digital printing process

[0037] Taking nylon fabric as an example, the acidic digital printing base paste described in this invention is used to pre-treat the nylon fabric using an immersion padding machine. After drying, the fabric undergoes digital printing, high-temperature steaming, color fixing, and washing, and is then dried to obtain a digitally printed fabric sample.

[0038] Example 6, Performance Testing

[0039] The acidic digital printing base pastes prepared in Examples 1 to 4 and Comparative Example 1 of this invention were used to prepare the corresponding fabrics according to the printing process described in Example 5. The printing fastness, K / S value and penetration rate of the above fabrics were tested according to the following methods (I) to (II). The test results are shown in Table 1 below.

[0040] (a) Print fastness test

[0041] 1. Color fastness to rubbing test of fabric:

[0042] In accordance with the requirements of GB / T 3920-2008 "Textiles - Tests for color fastness - Color fastness to rubbing", the samples were tested for color fastness to rubbing.

[0043] The color fastness to rubbing was assessed according to GB251-1995, "Gray Sample Card for Staining Assessment".

[0044] 2. Color fastness test for fabrics after soap washing:

[0045] In accordance with the requirements of GB / T 3921.1-2008 "Textiles - Tests for color fastness - Color fastness to washing", the samples were tested for color fastness to washing.

[0046] The color fastness to soap washing was assessed according to GB250-1995, "Gray Sample Card for Assessing Color Change".

[0047] (II) Determination of K / S value and permeability

[0048] Color yield determination: The K / S value of the fabric was measured using a COLOR-Eye7000A computer colorimeter. The higher the K / S value, the deeper the color.

[0049] Penetration rate determination: Twenty dots (2cm in diameter) were drawn from two dots on each sample using a computer-generated image. The dotted fabric was scanned using a computer scanner with settings of dpi, brightness -75, and contrast 50. The resulting images were analyzed using CPAS image processing software from Beijing Daheng Vision Imaging Co., Ltd., with an image tolerance of 140 (related to the color gradient analysis of the dot edges). The area (mm²) of the ink dots in the sample was obtained through image analysis. 2 The average of the penetration rates of each of the 20 ink dots is used as the evaluation index, and the calculation is shown in the following formula:

[0050] Permeation rate = (spotting area after process treatment - spotting area after printing) / spotting area after printing × 100%.

[0051] Table 1

[0052] Test sample Color fastness to rubbing color fastness to soap washing Penetration rate % K / S value Example 1 4-5 4-5 8.10 17.89 Example 2 4 4 8.54 16.99 Example 3 4 4～5 8.69 17.25 Example 4 4 4 8.21 17.02 Comparative Example 1 3-4 3-4 8.78 15.21

[0053] The results in the table above show that, compared with ordinary acidic digital printing base paste, the printed fabrics obtained by treating nylon fabrics with the acidic digital printing base paste prepared in Examples 1 to 4 of this invention have brighter printing colors and color fastness of 4-5. At the same time, due to the increase in color volume, the printed fabrics have fuller patterns and more vibrant colors. The K / S value and penetration rate are greatly improved. In particular, the acidic base paste prepared in Example 1 has the best performance.

[0054] Example 7

[0055] This embodiment investigated the effect of thickener on the performance of printing base paste. This embodiment followed the formula of Example 1, only changing the type and ratio of thickener. The weight percentage of thickener was 2.5%, and it was added to the formula according to the ratio in Table 2. The paste was tested for electrolyte resistance, K / S value, and penetration rate. The test methods for PVI, K / S value, and penetration rate were the same as those in Example 6.

[0056] PVI of digital printing paste: The viscosity of standard digital printing paste is determined by testing with an NDJ-1 rotary viscometer at 25°C.

[0057] Electrolyte resistance: expressed as viscosity retention rate. The viscosity of the above composite paste is calculated by adding 0.05% NaCl to the white paste. Viscosity retention rate = η 加Nacl后 / η 加Nacl前 The higher the viscosity retention rate, the better the electrolyte resistance.

[0058] The performance test results are shown in Table 3.

[0059] Table 2

[0060] experimental group Thickener components and weight ratios Experimental group 1 Corn fiber gum: polyacrylic acid: sodium montmorillonite / polypropylene amide composite = 1:1:0.8 Experimental group 2 Corn fiber gum: polyacrylic acid: sodium montmorillonite / polypropylene amide complex = 1:1.2:1 Experimental group 3 Corn fiber gum: polyacrylic acid: sodium montmorillonite / polypropylene amide composite = 1:1.5:1.5 Experimental group 4 Corn fiber gum: polyacrylic acid: sodium montmorillonite / polypropylene amide composite = 1:1.6:1.6 Experimental group 5 Corn fiber gum: polyacrylic acid: sodium montmorillonite / polypropylene amide composite = 1:1.8:1.8 Experimental group 6 Corn fiber gum: polyacrylic acid: sodium montmorillonite / polypropylene amide complex = 1:2:2 Experimental group 7 Corn fiber gum: polyacrylic acid: sodium montmorillonite / polypropylene amide complex = 1:2.5:2 Experimental group 8 Corn fiber gum Experimental group 9 Polyacrylic acid Experimental group 10 Sodium montmorillonite / polypropylene amide complex Experimental group 11 Corn fiber adhesive: polyacrylic acid = 1:1.6 Experimental group 12 Corn fiber gum: Sodium montmorillonite / polypropylene amide composite = 1:1.6 Experimental group 13 Polyacrylic acid:sodium montmorillonite / polypropylene amide composite = 1.6:1.6

[0061] Table 3

[0062]

[0063]

[0064] As shown in Table 3, when the content of thickener is 2.5%, changing its type and ratio will change its various properties. Experimental groups 1 to 7 changed the ratio of corn fiber gum, polyacrylic acid, and sodium montmorillonite / polypropylene amide composite. Among them, experimental groups 2 to 6 were better than experimental groups 1 and 7, while experimental groups 3 to 5 were better than other experimental groups. In particular, the color fastness of experimental group 4 can reach grade 4-5, and the K / S value, penetration rate, PVI and anti-electrolyte ability are the best. The thickener prepared by this experimental group has excellent thickening ability, anti-electrolyte performance and high color yield. Experimental groups 8-13 only changed the type of thickener, containing only one, two, or three of the three components: corn fiber gum, polyacrylic acid, and sodium montmorillonite / polypropylene amide complex. The proportions of each component were the same as in experimental group 4. As can be seen from the data in Table 3, the performance of these groups was not as good as that of the present invention. This indicates that when the three components of the thickener are combined in a specific ratio, there is an optimal synergistic effect, which further improves the viscosity of the paste and enhances the penetration rate and coloring ability of the printing base paste.

[0065] Example 8

[0066] This embodiment sets up 14 to 20 experimental groups. The weight percentage formula and test results of each experimental group are shown in Table 4. The wrinkle resistance, antibacterial properties, print fastness, and K / S value of the fabric were tested respectively. The print fastness test and K / S value test methods are the same as in Example 6. The test methods for wrinkle resistance and antibacterial properties are as follows:

[0067] Dry wrinkle recovery angle: The dry wrinkle recovery angle is determined by the vertical method in GB / T3819 "Determination of wrinkle recovery of textile fabrics", and is expressed in the warp plus weft directions.

[0068] Antibacterial function test: GB20944.3-2008-T Evaluation of antibacterial function of textiles Part 3.

[0069] Table 4

[0070]

[0071] Table 4 shows that, as demonstrated in Examples 1 and Experimental Groups 14-16, when the total content of polyacrylic acid, malic acid, and chitosan quaternary ammonium salt remains constant, the absence of any one of these components reduces the wrinkle resistance of the fabric by approximately 20 degrees. This indicates a synergistic effect among polyacrylic acid, malic acid, and chitosan quaternary ammonium salt, further enhancing the wrinkle resistance of the fabric and enabling the digital printing paste to be used for digital printing. Examples 1 and Experimental Groups 17-20 show that, with other components remaining the same, changing the type and ratio of malic acid and chitosan quaternary ammonium salt affects antibacterial properties and color fastness. Furthermore, the absence of either malic acid or chitosan quaternary ammonium salt significantly reduces both antibacterial properties and color fastness, indicating that malic acid and chitosan quaternary ammonium salt possess antibacterial and color fastness-enhancing functions. The effect is particularly optimal when the weight ratio of malic acid to chitosan quaternary ammonium salt is 2:1.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. The application of an acidic digital printing base paste in the digital printing process of nylon fabrics, characterized in that, The acidic digital printing base paste is composed of the following components by weight percentage: 1.5-3% thickener, 2-5% cosolvent, 2-5% hygroscopic agent, 1-1.6% malic acid, 0.5-0.8% chitosan quaternary ammonium salt, 0.5-2.5% sodium chloride, 1-3% ammonium sulfate, and the balance being water. The thickener is composed of corn cellulose gum, polyacrylic acid, and sodium montmorillonite / polypropylene amide complex. The weight ratio of corn cellulose gum, polyacrylic acid, and sodium montmorillonite / polypropylene amide complex is corn cellulose gum: polyacrylic acid: sodium montmorillonite / polypropylene amide complex = 1:1.6:1.

6. The weight ratio of malic acid and chitosan quaternary ammonium salt is malic acid: chitosan quaternary ammonium salt = 2:

1.

2. The application according to claim 1, characterized in that, The cosolvent is xylenesulfonic acid and / or diethylene glycol ether.

3. The application as described in claim 1, characterized in that, The hygroscopic agent is glycerin.

4. An application as described in any one of claims 1 to 3, characterized in that, The preparation method of the acidic digital printing base paste includes the following steps: 1) Add the thickener to deionized water according to the weight ratio, mix well and stir, let stand for 8-18 hours to obtain the mixed paste; 2) Add the cosolvent, humectant, sodium chloride, ammonium sulfate, malic acid, and chitosan quaternary ammonium salt to the water in step 1) and stir until homogeneous to obtain the acidic digital printing base paste.

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