A method for the synergistic dispersion of a dispersant and a binder for the preparation of a nanocoating color paste

Abstract

The present application relates to the technical field of fabric coating, and provides a method for preparing nano-coating color paste by dispersing dispersant and adhesive, comprising the following steps: dispersing pigments and dispersant with aromatic structure in water and stirring, obtaining a mixed solution after a period of time; grinding the mixed solution, obtaining water-based pigment color paste; mixing adhesive with the water-based pigment color paste, adding deionized water and mixing uniformly, obtaining water-based pigment color paste / adhesive mixed solution, wherein the adhesive has aromatic structure; mixing the water-based pigment color paste / adhesive mixed solution and thickener solution, adding deionized water and mixing uniformly, obtaining nano-coating color paste. The printed fabric prepared by the nano-coating color paste has excellent coloring performance, dry and wet rubbing fastness, physical performance, ultraviolet protection performance and light fastness, and can give the curtain fabric good appearance retention.

Description

Technical Field

[0001] This invention relates to the field of fabric coating technology, and more particularly to a method for preparing nano-coating color paste by synergistic dispersion of dispersants and binders.

[0002] Technical terms: EHL-His refers to histidine-modified lignin-based superdispersant, EHL-Arg refers to arginine-modified lignin-based superdispersant, EHL-Lys refers to lysine-modified lignin-based superdispersant, NNO refers to sodium methylene bis(naphthalene) sulfonate, OP-10 refers to dodecylphenol polyoxyethylene ether, PAAS refers to sodium polyacrylate, WPU refers to waterborne polyurethane emulsion, WEP refers to waterborne epoxy resin emulsion, WPA refers to waterborne acrylate emulsion, SA refers to sodium alginate. Background Technology

[0003] Curtain fabrics, as functional decorative textiles, occupy an important position in architectural soft furnishings. Colored curtains, in particular, not only provide residents with a sense of pleasure and comfort through color adjustment, but also offer superior UV protection. Therefore, designing and manufacturing colored curtain fabrics is one of the important means to improve the aesthetics and functionality of curtains.

[0004] Currently, there are two main methods for preparing colored curtain fabrics: pigment printing and dyeing. Compared to dyeing, pigment printing applies pigments to the fabric surface through a coating process. It is non-selective towards fibers, has a wide range of applications, and can save 28.2% of colorant, 56.5% of auxiliaries, 100% of salt, 34.8% of electricity, 63.4% of steam, and 94.8% of water. Furthermore, pigments offer superior lightfastness, chemical resistance, and weather resistance compared to dyes, resulting in better weather resistance for curtain fabrics. Therefore, designing and developing high-performance water-based pigment pastes has always been a major research focus in the curtain fabric printing and dyeing industry.

[0005] However, due to the lack of affinity between pigments and fibers, external adhesives are required to adhere them to the fabric surface. The addition of additives can easily lead to secondary aggregation of water-based dispersed pigment pastes, resulting in light and uneven printed colors, affecting both aesthetics and functionality. Therefore, improving the compatibility between water-based pigment pastes and adhesives has become a key technical challenge in preparing high-quality water-based coating pastes. Summary of the Invention

[0006] This invention aims to overcome the aforementioned shortcomings of existing technologies and proposes a method for preparing nano-coating color pastes through the synergistic dispersion of dispersants and binders. The technical solution of this invention is as follows:

[0007] A method for preparing nano-coating color paste by synergistic dispersion of dispersant and binder includes the following steps:

[0008] S1. At room temperature, pigment and dispersant are dispersed in water and stirred. After a period of time, a mixture is obtained. The dispersant has an aromatic structure.

[0009] S2. Add the above mixture and grinding balls to a sand mill jar for grinding. After grinding for a certain period of time, filter and separate the grinding balls to obtain water-based pigment paste.

[0010] S3. Take a certain amount of adhesive and mix it with the above-mentioned water-based pigment paste, and add deionized water to mix evenly to obtain a water-based pigment paste / adhesive mixture, wherein the adhesive has an aromatic structure;

[0011] S4. Mix the above-mentioned water-based pigment paste / binder mixture and thickener solution, and add deionized water to mix evenly to obtain nano-coating paste; the content of binder in the nano-coating paste is 15-30wt%, and the content of water-based pigment paste is 3-6wt%.

[0012] As a preferred embodiment of the present invention, in step S1, the mass ratio of the pigment to the dispersant is 2-6:1.

[0013] In a preferred embodiment of the present invention, in step S1, the solid content of the mixture is 1.5-5 wt%.

[0014] As a preferred embodiment of the present invention, in step S1, the dispersant includes at least one of amino acid-modified lignin-based superdispersant, NNO, and OP-10.

[0015] As a preferred embodiment of the present invention, the amino acid-modified lignin-based superdispersant is an alkaline amino acid-modified lignin-based superdispersant, preferably including at least one of EHL-His, EHL-Arg, and EHL-Lys.

[0016] As a preferred embodiment of the present invention, in step S2, the grinding balls include at least one of zirconia beads and alumina beads.

[0017] As a preferred embodiment of the present invention, in step S2, the particle size of the grinding balls is 0.3-1.0 mm.

[0018] As a preferred embodiment of the present invention, in step S2, the mass ratio of the mixture to the grinding balls is 3-6:10-20.

[0019] As a preferred embodiment of the present invention, in step S2, the grinding speed is 1200-1800 rpm and the time is 6-24h.

[0020] As a preferred embodiment of the present invention, in step S3, the mixing is specifically performed by ultrasonication at a power of 50-200W for 5-20 minutes.

[0021] As a preferred embodiment of the present invention, in step S3, the particle size of the water-based pigment paste is similar to that of the binder.

[0022] As a preferred embodiment of the present invention, in step S4, the amount of thickener used in the thickener solution is 1.5-3.5 wt% of the total mass of the nano-coating pigment.

[0023] As a preferred embodiment of the present invention, the thickener in the thickener solution includes at least one of sodium alginate, gelatin, gum arabic, carrageenan, β-cyclodextrin, and sodium carboxymethyl cellulose.

[0024] The present invention also provides a method for preparing printed fabric, wherein a nano-coating pigment paste prepared by synergistic dispersion of a dispersant and an adhesive as described in any of the above claims is used to screen print the fabric, and the fabric is dried and then baked to obtain the printed fabric.

[0025] As a preferred embodiment of the present invention, the screen printing adopts a warp-direction scraping method.

[0026] As a preferred embodiment of the present invention, the number of times the scratch is applied is 1.

[0027] As a preferred embodiment of the present invention, the baking temperature is 50-170℃ and the time is 60-120s.

[0028] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0029] 1) This invention employs a dispersant containing an aromatic structure, which exhibits strong π-π interactions with an adhesive containing an aromatic structure, resulting in a synergistic dispersion effect. Ultimately, the particle size of the coating pigment is similar to that of the adhesive. The nano-coating pigment prepared by this invention can be used for fabric dyeing via screen printing. This method is simple and easy to operate, and does not require high-temperature and high-pressure dyeing processes.

[0030] 2) Compared with commercially available dyes / coatings, the printed fabrics prepared using the nano-coating pigments of this application exhibit excellent coloring performance, wet and dry rubbing fastness, air permeability, tensile strength, and fabric stiffness, thus providing excellent appearance retention for curtain fabrics. Specifically, the printed fabrics prepared by this invention achieve a K / S value as high as 4.4, wet and dry rubbing fastness up to grade 5 and grade 4 respectively, air permeability from 135.98 mm / s ± 1.86 to 157.76 mm / s ± 3.98, tensile strength from 1369.57 N ± 3.43 to 1700.90 N ± 10.75, and fabric stiffness from 3.63 cm ± 0.23 to 8.92 cm ± 0.16, thus providing excellent appearance retention for curtain fabrics.

[0031] 3) Compared with commercially available dyes / coatings, the printed fabrics prepared using the nano-coating pigments of this application exhibit excellent UV protection and sun resistance. Specifically, the printed fabrics prepared with the EHL-His@PR57:1 coating demonstrate excellent UV protection (UPF: 95.3±0.6662 and T...). UVA (4.7% ± 0.2080), which meets the requirements for UV protection products in GB / T 18830-2009; at the same time, its fading rate is only 1 / 2 of that of commercial dyes, demonstrating good resistance to sunlight. Attached Figure Description

[0032] Figure 1 The middle section shows the particle size distribution and chemical structure diagram of EHL-His@PR57:1 in a.WEP, b.WPA and c.WPU adhesives; the middle section shows the schematic diagram of the dispersion process of EHL-His@PR57:1 in the adhesive.

[0033] Figure 2 Particle size distribution and chemical structure diagrams of a. OP-10@PR57:1, b. NNO@PR57:1, c. PAAS@PR57:1 in WPU adhesive; d. Schematic diagram of the synergistic dispersion mechanism between dispersant and adhesive;

[0034] Figure 3 The aK / S value and bΔK / S value of printed fabrics under different thickener SA addition amounts; binder WPU addition amount: 30wt.%; baking temperature: 170℃.

[0035] Figure 4 Thickener SA addition: 3 wt.%; Baking temperature: 170℃; (This is used to determine the aK / S and b.ΔK / S values ​​of printed fabrics under different WPU adhesive addition amounts; Thickener SA addition: 3 wt.%; Baking temperature: 170℃)

[0036] Figure 5 The aK / S value and b.ΔK / S value of printed fabrics at different baking temperatures were determined by the following addition amounts: binder WPU: 30 wt.%; thickener SA: 3 wt.%.

[0037] Figure 6 The aK / S value and b.ΔK / S value of printed fabrics under different water-based pigment paste contents were determined by the following parameters: binder WPU addition amount: 30 wt.%; thickener SA addition amount: 3 wt.%; baking temperature: 90℃.

[0038] Figure 7Digital photographs of the appearance of a. EHL-His@PR57:1 printed fabric, b. NNO@PR57:1 printed fabric, c. CIDisperseRed 60 dyed fabric; cross-sectional views of d. EHL-His@PR57:1 printed fabric, e. NNO@PR57:1 printed fabric, f. CIDisperseRed 60 polyester dyed fabric.

[0039] Figure 8 a.UPF, bT for printed fabrics UVA c. Fading rate. Detailed Implementation

[0040] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the art or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0041] The experimental materials, instruments, and equipment used in specific embodiments of this invention are as follows:

[0042] Experimental materials:

[0043] Amino acid-modified lignin-based superdispersants (EHL-His, EHL-Arg, EHL-Lys), prepared in the laboratory; Pigment Red 57:1 (PR57:1), Guangdong Meidan Titanium Dioxide Pigment Co., Ltd.; Sodium methylene bis(naphthalene) sulfonate (NNO), dodecylphenol polyoxyethylene ether (OP-10), sodium polyacrylate (PAAS), Shandong Yousuo Chemical Technology Co., Ltd.; Waterborne polyurethane emulsion (WPU), waterborne epoxy resin emulsion (WEP), waterborne acrylate emulsion (WPA), Shenzhen Yoshida Chemical Co., Ltd.; Sodium alginate (SA, C6H7NaO6), Shanghai Aladdin Chemical Reagent Co., Ltd.

[0044] The preparation method of the amino acid-modified lignin-based superdispersant is as follows: Basic amino acids are grafted onto the EHL molecular structure using the Mannich reaction. The specific process is as follows: 4.0 g of EHL is dissolved in 20 mL of 1 mol / L NaOH aqueous solution and stirred at room temperature for 24 h to ensure complete dissolution. Then, 0.8 g of basic amino acids and 50 wt% glutaraldehyde (glutaraldehyde to amino acid mass ratio of 1:1) are added, stirred, and heated to 60 °C. After reacting for 4 h, the pH of the reaction solution is adjusted to 7.5 with 0.5 mol / L HCl aqueous solution. After centrifugation to remove impurities, the solution is dialyzed and concentrated. Finally, it is freeze-dried to obtain a dark brown solid powder (EHL-AA, where EHL is enzymatically hydrolyzed lignin, and AA consists of Arg, Lys, and His).

[0045] Experimental instruments and equipment:

[0046] CY-1 sand mill, Shaoxing Shangyu Daoxu Geotechnical Instrument Factory; JSM-1400 transmission electron microscope, Nippon Electronics Co., Ltd.; YG461E automatic fabric air permeability tester, Nantong Hongda Experimental Instrument Co., Ltd., China; HD207N automatic fabric stiffness tester, Nantong Hongda Experimental Instrument Co., Ltd., China; Y571C rubbing color fastness tester, Wenzhou Fangyuan Instrument Co., Ltd.; YG912E textile UV protection performance tester, Wenzhou Jigao Testing Instrument Co., Ltd.; YG026Q fabric strength tester, Ningbo Textile Instrument Factory; JW-UV1 ultraviolet aging test chamber, Shanghai Juwei Instrument Equipment Co., Ltd.

[0047] The following are specific examples.

[0048] Example 1

[0049] A method for preparing nano-coating color paste by synergistic dispersion of dispersant and binder includes the following steps:

[0050] S1. At room temperature, 1.125g of PR57:1 and 0.281g of EHL-His were dispersed in water and stirred. After stirring at room temperature for 12 hours, a mixture was obtained with a solid content of 3wt%.

[0051] S2. Add the above mixture and 0.4-0.6 mm zirconia beads to a sand mill at a ratio of 45:150 (wt.%). Grind at 1400 rpm for 10 hours. Then filter and separate the zirconia beads to obtain water-based pigment paste PR57:1@EHL-His.

[0052] S3. Take the adhesive WPU and mix it with the above-mentioned water-based pigment paste. The water-based pigment paste is 50μL. Add deionized water to make the total weight 10g. Then, sonicate it in an ultrasonic cleaner at 100W power for 10min to obtain the water-based pigment paste / adhesive mixture (PR57:1@EHL-His / WPU mixture).

[0053] S4. Mix the above-mentioned water-based pigment paste / binder mixture and thickener solution, and add deionized water to make up to 20 mL. Stir thoroughly on a magnetic stirrer to obtain nano-coating paste; wherein, the thickener solution is sodium alginate (SA) solution, and the obtained nano-coating paste contains 30 wt% binder, 4 wt% water-based pigment paste, and 3 wt% thickener.

[0054] The nano-coating pigment obtained above was screen printed onto a plain polyester fabric using a warp-direction scraping method, with one scraping pass. After screen printing, the fabric was dried at room temperature and then baked at 90°C for 90 seconds to obtain the printed fabric.

[0055] Example 2

[0056] Replace EHL-His with NNO, and the rest is the same as in Example 1.

[0057] Example 3

[0058] Replace EHL-His with OP-10, and the rest is the same as in Example 1.

[0059] Example 4

[0060] The binder content in the obtained nano-coating color paste is 15 wt%, and the rest is the same as in Example 1.

[0061] Example 5

[0062] The obtained nano-coating color paste contains 20 wt% binder, and the rest is the same as in Example 1.

[0063] Example 6

[0064] The obtained nano-coating color paste contains 25 wt% binder, and the rest is the same as in Example 1.

[0065] Example 7

[0066] The obtained nano-coating color paste contains 1.5 wt% thickener, and the rest is the same as in Example 1.

[0067] Example 8

[0068] The thickener content in the obtained nano-coating color paste is 2wt%, and the rest is the same as in Example 1.

[0069] Example 9

[0070] The obtained nano-coating color paste contains 2.5 wt% thickener, and the rest is the same as in Example 1.

[0071] Example 10

[0072] The obtained nano-coating color paste contains 3.5 wt% thickener, and the rest is the same as in Example 1.

[0073] Example 11

[0074] The baking temperature was 50°C, and the rest was the same as in Example 1.

[0075] Example 12

[0076] The baking temperature was 90℃, and the rest was the same as in Example 1.

[0077] Example 13

[0078] The baking temperature was 130℃, and the rest was the same as in Example 1.

[0079] Example 14

[0080] The obtained nano-coating color paste contains 3 wt% water-based pigment color paste, and the rest is the same as in Example 12.

[0081] Example 15

[0082] The obtained nano-coating color paste contains 5 wt% water-based pigment color paste, and the rest is the same as in Example 12.

[0083] Example 16

[0084] The obtained nano-coating color paste contains 6 wt% water-based pigment color paste, and the rest is the same as in Example 12.

[0085] Example 17

[0086] In step S1, the mass ratio of PR57:1 to EHL-His is 3:1, and the rest is the same as in Example 12.

[0087] Example 18

[0088] In step S1, the mass ratio of PR57:1 to EHL-His is 5:1, and the rest is the same as in Example 12.

[0089] Example 19

[0090] Replace EHL-His with NNO, and the rest is the same as in Example 12.

[0091] Example 20

[0092] In step S1, the solid content of the resulting mixture is 1.5 wt%, and the rest is the same as in Example 12.

[0093] Example 21

[0094] In step S1, the solid content of the resulting mixture is 2.2 wt%, and the rest is the same as in Example 12.

[0095] Example 22

[0096] In step S1, the solid content of the resulting mixture is 3.5 wt%, and the rest is the same as in Example 12.

[0097] Example 23

[0098] In step S1, the solid content of the resulting mixture is 5 wt%, and the rest is the same as in Example 12.

[0099] Example 24

[0100] In step S1, EHL-His is replaced with EHL-Arg, and the rest is the same as in Example 12.

[0101] Example 25

[0102] In step S1, EHL-His is replaced with EHL-Lys, and the rest is the same as in Example 12.

[0103] This invention employs a dispersant containing an aromatic structure, which exhibits strong π-π interactions with an adhesive containing an aromatic structure, resulting in a synergistic dispersion effect. Ultimately, the particle size of the coating pigment is similar to that of the adhesive. The nano-coating pigment prepared by this invention is used for screen printing to dye fabrics; the method is simple and easy to operate, requiring no high-temperature, high-pressure dyeing process. Compared with commercial dyes / coatings, printed fabrics prepared using the nano-coating pigment of this application exhibit excellent coloring properties, dry and wet rubbing fastness, air permeability, tensile strength, and fabric stiffness, providing curtain fabrics with good appearance retention, as well as excellent UV protection and sun resistance.

[0104] Comparative Example 1

[0105] The obtained nano-coating color paste contains 5 wt% binder, and the rest is the same as in Example 1.

[0106] Comparative Example 2

[0107] The obtained nano-coating color paste contains 10 wt% binder, and the rest is the same as in Example 1.

[0108] Comparative Example 3

[0109] The binder content in the obtained nano-coating color paste is 35 wt%, and the rest is the same as in Example 1.

[0110] Comparative Example 4

[0111] The adhesive used is PAAS, and the rest is the same as in Example 1.

[0112] The poor compatibility between PAAS and WPU makes it difficult for PR57:1 to be completely dispersed further, resulting in poor pigment dispersion in the obtained nano-coating color paste. Consequently, the printed fabric produced by screen printing has poor color uniformity and large color difference.

[0113] Comparative Example 5

[0114] Replace WPU with WEP, and the rest is the same as in Example 1.

[0115] The average particle size of the water-based pigment paste is similar to that of the WEP binder, at 358 nm, which is relatively large (38 nm in Example 1). As a result, the pigment dispersion in the obtained nano-coating paste is poor, and the color uniformity of the printed fabric obtained by screen printing is poor, resulting in color difference in the fabric.

[0116] Comparative Example 6

[0117] Replace WPU with WPA, and the rest is the same as in Example 1.

[0118] The average particle size of the water-based pigment paste is similar to that of WPA, at 198 nm, which is relatively large (38 nm in Example 1). As a result, the pigment dispersion in the obtained nano-coating paste is poor, and the color uniformity of the printed fabric obtained by screen printing is poor, resulting in color difference in the fabric.

[0119] Comparative Example 7

[0120] The baking temperature was 200℃, and the rest was the same as in Example 1.

[0121] Comparative Example 8

[0122] The obtained nano-coating color paste contains 1 wt% water-based pigment color paste, and the rest is the same as in Example 12.

[0123] Comparative Example 9

[0124] The obtained nano-coating color paste contains 2 wt% water-based pigment color paste, and the rest is the same as in Example 12.

[0125] Comparative Example 10

[0126] The nano-coating pigment was replaced with commercially available dye pigment CIDisperse Red 60, and the coloring process was high-temperature and high-pressure dyeing, with the rest being the same as in Example 12.

[0127] The following investigation explores the effects of adhesive type and particle size, dispersant structure on the particle size distribution of water-based pigment pastes, and their impact on the resulting nano-coating pastes and printed fabrics.

[0128] The water-based pigment pastes obtained in Examples 1-25 can all be well dispersed in the binder. The particle size of the pigment pastes exhibits a single-peak distribution, and the average particle size is similar to that of the binder.

[0129] The methods for characterizing the particle size and morphology of water-based pigment pastes / binders are as follows:

[0130] Take 100 μL of water-based pigment paste / binder mixture, dilute it with 5 mL of deionized water, and scan the sample at 25 °C using a nanoscale laser particle size analyzer to record its particle size distribution.

[0131] 100 μL of aqueous pigment paste and aqueous pigment paste / binder mixture were diluted with 5 mL of deionized water and ultrasonically dispersed, then dropped onto a copper mesh surface and dried at room temperature. Subsequently, the morphology and size of the samples were characterized using a transmission electron microscope (TEM) from JEOL Ltd. at 200 kV. Finally, the particle size of the samples was measured using ImageJ-win64 software.

[0132] The results are shown in Table 1. Figure 1-2 .

[0133] Table 1 Formulation of Water-based Pigments / Pastes / Binders

[0134]

[0135]

[0136] like Figure 1 As shown in Figure a, the average particle size of pure EHL-His@PR57:1 is 146 nm and exhibits a normal distribution. When the amount of adhesive WEP added to EHL-His@PR57:1 increases to 0.5 wt.%, the particle size peak of EHL-His@PR57:1 / WEP-0.5 at 126 nm gradually disappears, and a new particle size peak appears at 420 nm and gradually intensifies. When the WEP content increases to 5 wt.%, the particle size peak of EHL-His@PR57:1 / WEP-5 at 126 nm completely disappears, and a single peak appears at 489 nm and exhibits a normal distribution. When the WEP content further increases to 10 wt.%, the average particle size of EHL-His@PR57:1 / WEP-10 decreases from 489 nm to 358 nm, which is similar to the particle size of adhesive WEP. Figure 1 As shown in b, when the amount of adhesive WPA added to EHL-His@PR57:1 increases to 0.5 wt.%, the average particle size distribution of EHL-His@PR57:1 / WPA-0.5 increases from 146 nm to 198 nm, exhibiting a normal distribution. When the WPA content increases to above 5 wt.%, the average particle size of EHL-His@PR57:1 / WPA remains unchanged and is similar to the WPA particle size. Figure 1 As shown in Figure c, when the WPU content of the adhesive increases to 0.5 wt.%, EHL-His@PR57:1 / WPU-0.5 exhibits particle size peaks at both 146 nm and 38 nm. When the WPU content increases to 5.0 wt.%, the particle size peak at 126 nm of EHL-His@PR57:1 / WPU-5.0 completely disappears, and a single peak dispersion occurs at 38 nm. When the WPU content further increases to 10.0 wt.%, the average particle size of EHL-His@PR57:1 / WPU-10 remains at 38 nm, similar to the WPU particle size.

[0137] As can be seen from the above, the dispersion process of EHL-His@PR57:1 in the adhesive may be as follows: Figure 1 As shown in diagram d, with the addition of the binder, the pigment tends to move and bind towards the binder due to the hydrophobic and electrostatic forces between the dispersant and the binder. When the binder content is low, the binder cannot completely coat the pigment, resulting in a bimodal particle size distribution. When the binder content is sufficient, the pigment is completely coated by the binder, and the particle size distribution changes from bimodal to unimodal, with the average particle size being similar to that of the binder. WPU exhibits good amphiphilicity, resulting in the smallest aggregated particle size in aqueous solution. EHL-His@PR57:1 shows the best dispersion performance in WPU.

[0138] Figure 2 As shown in Figure a, when the content of WPU in PAAS@PR57:1 increases from 0.5 wt.% to 10.0 wt.%, the particle size of the pigments all exhibit a bimodal distribution. Figure 2 As shown in b and c, when the content of WPU in OP-10@PR57:1 and NNO@PR57:1 color pastes is 0.5 wt.% and 5.0 wt.%, respectively, the particle size of the color pastes also exhibits a bimodal distribution. When the content of WPU in OP-10@PR57:1 and NNO@PR57:1 color pastes is further increased to 10.0 wt.%, the particle size of the color pastes exhibits a unimodal distribution, and the average particle size is similar to that of WPU. Figure 1 As shown in Figure c, when the WPU content in the EHL-His@PR57:1 color paste is 0.5 wt.%, the color paste particle size exhibits a bimodal distribution. When the WPU content is further increased to 5.0 wt.%, the color paste particle size exhibits a unimodal distribution, and the average particle size is similar to that of WPU.

[0139] Depend on Figure 1 c and Figure 2 Based on the chemical structures of the dispersants and binders, WPU contains aromatic ring structures, which readily form strong π-π interactions with the aromatic structures in EHL-His, OP-10, and NNO dispersants, resulting in a synergistic dispersion effect. This further enhances the dispersibility of PR57:1 in the mixture (e.g., ...). Figure 2 d). Meanwhile, the higher the content of aromatic structures in the dispersant (EHL-His > NNO > OP-10), the better its compatibility with WPU, and the better the synergistic dispersion effect can be achieved at low concentrations. Figure 1 c) This method is expected to form a thin coating on the fabric surface, ensuring good breathability. Because PAAS lacks a benzene ring structure, it has poor compatibility with WPU, making it difficult to completely disperse PR57:1 further. Figure 2 d), therefore the particle size is bimodal. Figure 2 c).

[0140] Samples with bimodal particle size distribution have poor pigment dispersion in the obtained nano-coating paste, resulting in poor color uniformity of the printed fabric produced by screen printing.

[0141] The printed fabrics obtained in the examples and comparative examples were tested and characterized. The specific experimental methods are as follows:

[0142] (I) Color Characterization of Polyester Printed Fabrics

[0143] The color depth (K / S value) of dyed polyester fabric samples was tested using a colorimetric spectrometer. Under testing conditions of D65 light source at 10°, each sample fabric was folded into 4 layers, and measurements were taken at multiple different locations, with the average value recorded. A higher K / S value indicates a darker color; a lower K / S value indicates a lighter color.

[0144] (II) Characterization of color fastness to rubbing of polyester printed fabrics

[0145] The color fastness to rubbing of polyester printed fabrics was tested using GB / T 3920-2008 "Textiles - Tests for Color Fastness to Rubbing". Rectangular samples of 50mm × 140mm were cut after conditioning. The dry and wet rubbing fastness of the polyester printed fabric surface was tested using a rubbing fastness tester. The conditioned sample was placed flat on a platform, with the warp direction aligned with the running direction of the rubbing head. A standard rubbing cloth (95% moisture content) was fixed to the rubbing head. The dry (wet) rubbing fastness was tested under the condition of 10 reciprocating cycles per second. The dry (wet) rubbing fastness of the printed fabrics was rated according to GB / T 251-2008 "Textiles - Tests for Color Fastness to Rubbing - Assessment of Staining - Gray Scale".

[0146] (III) Physical property characterization of polyester printed fabrics

[0147] Fabric areal density characterization: also known as basis weight per unit area, refer to GB / T 4669-2008 "Textiles - Determination of Mass per Unit Length and Mass per Unit Area of ​​Woven Fabrics". First, the polyester printed fabric is woven in standard atmosphere for 24 hours to pre-condition. Then, five 5cm × 5cm samples are cut, weighed on an electronic balance, and the areal density is calculated using the following formula.

[0148]

[0149] In the formula, m c The unit area mass of the polyester printed fabric after moisture conditioning, in g / m² 2 m is the measured mass of the conditioned polyester printed fabric, in grams; S is the area of ​​the conditioned polyester printed fabric cut in m². 2 .

[0150] Stiffness characterization: Using GB / T 18318.1-2009 "Determination of bending properties of textiles - Part 1: Inclined plane method", the conditioned polyester printed fabric was first cut into rectangular samples of 25mm × 250mm. Using an automatic fabric stiffness tester, the length of the extended part was measured when the front end of the polyester printed fabric was bent to a plane that forms a 45° angle with the extended plane of the platform.

[0151] Air permeability characterization: The air permeability of the conditioned polyester printed fabric was determined using an automatic fabric air permeability tester, in accordance with GB / T 5453-1997 "Textiles - Determination of Air Permeability of Fabrics". A 20cm... 2 The head area was set at a pressure difference of 100 Pa, and the test was conducted at 20℃±2 and 65%±4 relative humidity.

[0152] Fabric mechanical property characterization: The tensile strength of the conditioned polyester printed fabric was tested using a fabric tensile testing machine according to CB / T3923.1-2013 "Textiles - Tensile Properties of Fabrics - Part 1: Determination of Breaking Strength and Elongation at Break (Strip Method)". Three conditioned polyester printed fabrics (50mm × 150mm) were prepared, and their tensile strength was tested under the conditions of a spacing of 100mm and a tensile speed of 100mm / min. The results were compared with the requirements in GB / T 19817-2005 "Textiles - Coated Fabrics for Decorative Purposes". Furthermore, since this fabric is a plain weave fabric, its warp and weft tensile strengths are consistent; therefore, the warp tensile strength was measured uniformly.

[0153] (iv) Microscopic morphology characterization of polyester printed fabrics

[0154] The surface and cross-sectional microstructure of polyester fabrics before and after dyeing were observed using an optical microscope. First, the polyester fabrics, both before and after dyeing, were cut into 5cm × 5cm rectangles and fixed to glass slides with double-sided tape. The surface microstructure was studied using transmission mode. Subsequently, the fabric was coated and cured with resin, and then polished at an angle perpendicular to the fabric surface using an automated metallographic sample polishing machine. After smoothing, the cross-sectional morphology was observed under the reflection mode of an optical microscope.

[0155] (V) Characterization of UV protection performance of polyester printed fabrics

[0156] Ultraviolet Protection Factor (UPF) Characterization: The ultraviolet protection performance of polyester printed fabrics was determined using a textile ultraviolet protection performance tester in accordance with GB / T 18830-2009 "Evaluation of Ultraviolet Protection Performance of Textiles".

[0157] (vi) Characterization of lightfastness of polyester printed fabrics

[0158] The test was conducted under single-cycle test condition 1 in GB / T 31899-2015 "Textiles - Weather Resistance to Ultraviolet Exposure". First, the fabric was cut into 5cm × 5cm rectangular samples, and then subjected to a UV aging test in an ultraviolet aging chamber. The change in fading rate (R) before and after light exposure was calculated using the following formula, and the lightfastness stability between PR57:1 and CIDisperse Red 60 was compared. Furthermore, the effect of EHL-His as a superdispersant on improving the sunlight resistance of PR57:1 was compared.

[0159]

[0160] In the above formula, K / S(a) is the K / S value of the printed polyester fabric before ultraviolet light irradiation; K / S(b) is the K / S value of the printed polyester fabric after ultraviolet light irradiation.

[0161] The following are the specific experimental data.

[0162] 1. Effects of thickener addition amount on K / S value, ΔK / S value and rubbing fastness of printed fabrics

[0163] The K / S value, ΔK / S value, and rubbing fastness of the printed fabrics obtained in Examples 1 and 8-11 were determined, and the results are shown in the figure. Figure 3 And Table 2.

[0164] Table 2. Color fastness to dry and wet rubbing of printed fabrics with different amounts of thickener SA.

[0165]

[0166] like Figure 3 As shown in a and b, when the amount of thickener SA increased from 1.5 wt.% to 3.0 wt.%, the K / S value of the polyester printed fabric decreased from 5.1 to 4.2, and the standard deviation ΔK / S value decreased from 0.11 to 0.03. When the amount of thickener SA was further increased to 3.5 wt.%, the K / S value further decreased to 3.9, and the standard deviation ΔK / S value increased to 0.06. These results indicate that when the amount of thickener SA is 3 wt.%, it exhibits better color depth and excellent color uniformity. This is because thickener SA can reduce the fluidity of the pigment paste, which helps to avoid color differences caused by bleeding after printing.

[0167] As shown in Table 2, when the amount of thickener SA increased from 1.5 wt.% to 3.0 wt.%, the dry rubbing color fastness of the polyester printed fabric improved to grade 5, and the wet rubbing color fastness improved to grade 4. Studies have shown that after SA and WPU are blended into a film, they can form an interpenetrating network under hydrogen bonding, creating a dense physical cross-linked network, which improves the dry and wet rubbing color fastness of the fabric. This also explains why the increase in thickener SA leads to an increase in the rubbing color fastness of the polyester printed fabric. When the amount of thickener SA is further increased to 3.5 wt.%, the dry and wet rubbing color fastness of the polyester printed fabric remains unchanged. Therefore, considering production costs and process operation, the amount of thickener SA does not need to be further increased.

[0168] 2. Effects of adhesive addition amount on K / S value, ΔK / S value and rubbing fastness of printed fabrics

[0169] The K / S value, ΔK / S value, and rubbing fastness of the printed fabrics obtained in Examples 1, 4-6, and Comparative Examples 1-3 were determined, and the results are listed below. Figure 4 And Table 3.

[0170] Table 3. Color fastness to dry and wet rubbing of printed fabrics with different WPU binder addition amounts

[0171]

[0172] like Figure 4 As shown in Figure a, as the amount of binder WPU added increased from 5 wt.% to 35 wt.%, the K / S value of the polyester printed fabric increased from 1.8 to 4.4. This is because PR57:1 has no affinity with the fiber and needs to rely on the binder WPU to fix it to the fabric surface; therefore, the K / S value of the fabric increases with the increase of binder addition. When the binder WPU addition amount is 5 wt.% and 10 wt.%, the K / S values ​​of the polyester printed fabric are 1.8 and 2.2, respectively, indicating that the coloring ability of PR57:1 is relatively low; when the binder WPU addition amount is 15 wt.%, the K / S value of the polyester printed fabric is close to 3, at which point PR57:1 can be well fixed to the fabric surface. Figure 4 As shown in b, when the amount of binder WPU added increased from 5 wt.% to 30 wt.%, the standard deviation ΔK / S value increased from 0.02 to 0.03, showing only a slight change, indicating good color uniformity. However, when the binder amount was further increased to 35 wt.%, the standard deviation ΔK / S value increased by 15.7 times, indicating poor fabric color uniformity. This may be because as the amount of binder WPU added further increases, the viscosity of the water-based paint pigment increases sharply, leading to reduced fluidity and uneven pigment deposition.

[0173] As shown in Table 3, when the WPU binder content increased from 5 wt.% to 30 wt.%, the dry rubbing color fastness of the polyester printed fabric improved to grade 5, and the wet rubbing color fastness improved to grade 4. This is because as the WPU binder content further increased, the pigment was gradually and completely encapsulated, resulting in a significant improvement in both dry and wet rubbing color fastness. With the WPU binder content further increased to 35 wt.%, the dry and wet rubbing color fastness remained unchanged.

[0174] 3. Effects of baking temperature on the K / S value, ΔK / S value, and color fastness to rubbing of printed fabrics

[0175] The K / S value, ΔK / S value, and rubbing fastness of the printed fabrics obtained in Examples 1, 11-13, and Comparative Example 7 were determined, and the results are listed below. Figure 5 And Table 4.

[0176] Table 4. Color fastness to dry and wet rubbing of printed fabrics at different baking temperatures

[0177]

[0178] Depend on Figure 5 As shown in Figure a, when the baking temperature increases from 50℃ to 90℃, the K / S value of the polyester printed fabric increases from 4.1 to 4.4. When the baking temperature increases from 90℃ to 130℃, the fabric K / S value does not change significantly. When the baking temperature increases to 170℃, the fabric K / S value shows a slight decreasing trend, dropping to 4.2. When the temperature is further increased to 200℃, the fabric K / S value drops sharply to 1.53. This may be because the excessively high temperature damages the color development structure of PR57:1, leading to a reduction in its coloring ability. Figure 5 As shown in b, when the baking temperature is 90℃, the standard deviation ΔK / S value of the polyester printed fabric is the smallest (0.02), indicating that the fabric has the best apparent color uniformity.

[0179] As shown in Table 4, when the baking temperature increased from 50℃ to 90℃, the dry rubbing color fastness of the polyester printed fabric remained at grade 5, while the wet rubbing color fastness improved to grade 4. When the baking temperature increased to 170℃, the dry and wet rubbing color fastness remained unchanged. However, when the baking temperature was further increased to 200℃, the dry and wet rubbing color fastness of the polyester printed fabric decreased to grades 3-4 and 3, respectively. These results indicate that appropriately increasing the baking temperature can promote the intensification of WPU macromolecular chain movement, allowing its hydrophobic structure to move to the coating surface, thereby improving its wet rubbing color fastness. Excessively high baking temperatures may lead to the breakage of WPU macromolecular chains, resulting in a decrease in the dry and wet rubbing color fastness of the fabric.

[0180] 4. Effects of water-based pigment paste content on K / S, ΔK / S values ​​and rubbing fastness of printed fabrics

[0181] The K / S value, ΔK / S value, and rubbing fastness of the printed fabrics obtained in Examples 1, 14-16, and Comparative Examples 8-9 were determined, and the results are listed below. Figure 6 See Table 5.

[0182] Table 5. Color fastness to dry and wet rubbing of printed fabrics with different water-based pigment paste contents.

[0183]

[0184] like Figure 6 As shown in Figure a, as the EHL-His@PR57:1 content increased from 1 wt.% to 4 wt.%, the K / S value of the polyester printed fabric increased from 1.0 to 4.4. When the EHL-His@PR57:1 content was 1 wt.% and 2 wt.%, the K / S values ​​of the polyester printed fabric were 1.0 and 2.6, respectively, indicating that PR57:1 had low coloring ability. When the EHL-His@PR57:1 content was 3 wt.%, the K / S value was 3.2, at which point PR57:1 could be well fixed to the fabric surface. As the EHL-His@PR57:1 content further increased to 6 wt.%, the K / S value of the polyester printed fabric did not change significantly. Figure 6 As shown in b, when the EHL-His@PR57:1 content increases from 1 wt.% to 6 wt.%, the highest standard deviation ΔK / S of the polyester printed fabric is only 0.03, demonstrating good color uniformity.

[0185] As shown in Table 5, the dry rubbing color fastness of polyester printed fabrics prepared with different EHL-His@PR57:1 contents all reached grade 5. However, with the increase of EHL-His@PR57:1 content, the wet rubbing color fastness of the fabric decreased from grade 4-5 to grade 4. This is because the increase of EHL-His@PR57:1 content slightly reduced the continuity of the coating film on the fabric surface, resulting in a slight decrease in wet rubbing color fastness.

[0186] 5. The effect of pigment type on K / S, ΔK / S values ​​and rubbing fastness of polyester printed fabrics

[0187] The K / S value, ΔK / S value, and rubbing fastness of the printed fabrics obtained in Examples 12, 19, and Comparative Example 10 were determined, and the results are listed below. Figure 7 See Table 6.

[0188] Table 6. Color fastness to dry and wet rubbing of fabrics printed with different water-based pigment pastes.

[0189]

[0190] like Figure 7As shown in a, b, and c, under optimal formulation and printing process conditions, the K / S values ​​of polyester printed fabrics prepared with NNO@PR57:1 and EHL-His@PR57:1 coatings, and polyester dyed fabrics prepared with CIDisperse Red 60 dye, are 4.4, 3.8, and 3.2, respectively, indicating that both pigment and dye pigments produce polyester printed fabrics with good color depth. Furthermore, the standard deviation of all prepared polyester printed fabrics is 0.02, indicating that both pigment and dye pigments exhibit good color uniformity. It is noteworthy that the polyester printed fabric prepared with EHL-His@PR57:1 coating has the highest K / S value. This may be due to the deepening effect of the lignin-based superdispersant (EHL-His). Figure 7 As shown in d and e, the cross-sections of NNO@PR57:1 and EHL-His@PR57:1 pigment-printed fabrics are white, indicating that the pigment is only fixed to the polyester fiber surface by the binder, and the coating is so thin that its thickness is difficult to measure under a microscope. After high-temperature and high-pressure dyeing, CIDisperse Red 60 disperse dye enters the fiber interior in molecular form, and the cross-section of the fabric appears red. Figure 7 d). Therefore, the wet rubbing color fastness of fabrics dyed with CIDisperse Red 60 reaches grade 4-5, which is better than grade 4 of NNO@PR57:1 and EHL-His@PR57:1 pigment-printed fabrics (Table 6). Meanwhile, the dry rubbing color fastness of all three dyed fabrics reaches grade 5 (Table 6).

[0191] 6. The Influence of Pigment Type on the Physical Properties of Polyester Printed Fabrics

[0192] The physical properties of the printed fabrics obtained in Examples 12, 21, and Comparative Example 10 were tested, and are detailed in Table 7. The results show that, compared with other commercially available dye pastes, the polyester printed fabrics prepared with the nano-coating paste provided by the present invention have excellent physical properties.

[0193] Table 7. Fabric weight, air permeability, stiffness, and tensile strength of fabrics printed with different water-based pigment pastes.

[0194]

[0195] As shown in Table 7, after dyeing with CIDISperse Red 60 dye, there were no significant changes in the fabric weight, air permeability, stiffness, and breaking strength of the dyed fabric compared to the original fabric. Printing of polyester fabric with pigments (NNO@PR57:1 and EHL-His@PR57:1) reduced its weight from 200.92 g / m². 2 ±3.34 increased to 225.87 g / m2 ±2.82 (NNO@PR57:1) and 225.38 g / m 2 ±2.46 (EHL-His@PR57:1). Air permeability tests showed that the air permeability increased from the original 135.98 mm / s ±1.86 to 146.25 mm / s ±2.86 (NNO@PR57:1) and 157.76 mm / s ±3.98 (EHL-His@PR57:1), respectively. It is noteworthy that pigment-printed fabrics exhibit superior air permeability compared to dye-dyed fabrics. This is because the tight coating of the adhesive results in a more compact multifilament structure in the polyester filament, a smaller filament diameter, larger fabric pores, and improved air permeability. Meanwhile, the tensile strength of polyester printed fabrics increased from the original 1369.57 N ± 3.43 to 1701.90 N ± 4.24 (NNO@PR57:1) and 1700.90 N ± 10.75 (EHL-His@PR57:1), which is far higher than the tensile strength requirements for interior decorative fabrics in GB / T19817-2005 "Textiles - Coated Fabrics for Decoration". Due to the influence of adhesives, the stiffness of polyester printed fabrics increased from 3.63 cm ± 0.23 to 9.31 cm ± 0.18 (NNO@PR57:1) and 8.92 cm ± 0.16 (EHL-His@PR57:1). Zhang Miaomiao et al.'s research on stiffness finishing of curtain fabrics found that increasing the stiffness of curtains to 8.88 cm can give them good appearance retention.

[0196] 7. Analysis of UV protection properties and lightfastness of polyester printed fabrics

[0197] The UV protection properties and lightfastness of the polyester printed fabrics obtained in Examples 12, 21, and Comparative Example 10 were characterized and analyzed. The results are shown in the figure. Figure 8 The results show that, compared with commercially available dye pastes, the polyester printed fabrics prepared with the nano-coating paste provided by this invention have excellent UV protection properties and lightfastness.

[0198] like Figure 8As shown in Figure a, the UPF values ​​of polyester fabrics improved after printing / dyeing treatments with CIDisperse Red 60, NNO@PR57:1, and EHL-His@PR57:1, respectively. The UPF values ​​were ranked as follows: 67.1±0.3 (Originfabric) < 82.0±1.2 (CIDisperse Red 60) < 82.7±1.0 (NNO@PR57:1) < 95.3±0.7 (EHL-His@PR57:1). This is because the chromophores in the colorants have UV absorption properties, reducing UV transmittance and giving the polyester-dyed fabrics superior UV protection performance. Figure 8 As shown in b, after dyeing, the T of the polyester fabric UVA The values ​​decreased from 11.80% ± 0.1 (Origin fabric) to 5.13% ± 0.1 (CIDisperse Red 60), 5.08% ± 0.0436 (NNO@PR57:1), and 4.73% ± 0.2 (EHL-His@PR57:1), respectively. It is noteworthy that only polyester printed fabrics prepared using EHL-His@PR57:1 meet the requirements for UV-protective products in GB / T 18830-2009 "Evaluation of Ultraviolet Protection Performance of Textiles," i.e., UPF > 40 and T... UVA <5%. This is because lignin molecules contain a large number of benzene rings, conjugated structures, and groups such as aldehydes and ketones that can absorb ultraviolet light, forming a good synergistic effect with pigments, further improving the ultraviolet protection performance of polyester printed fabrics.

[0199] like Figure 8 As shown in Figure c, the fading rates of polyester dyed fabrics after sun exposure tests were 38.5% ± 0.02 (CIDisperse Red 60), 33.7% ± 0.04 (NNO@PR57:1), and 19.9% ​​± 0.01 (EHL-His@PR57:1), respectively. Among these, the fading rate of the dyed fabric prepared with EHL-His@PR57:1 was only half that of the others, exhibiting the best sun exposure resistance. This is because the lignin-based superdispersant has excellent UV absorption and antioxidant properties, encapsulating the pigments and protecting them from sunlight, thus greatly improving the fabric's colorfastness to sunlight.

[0200] The above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various other corresponding changes and modifications based on the technical solutions and concepts described above, and all such changes and modifications should fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing nano-coating color paste by synergistic dispersion of a dispersant and a binder, characterized in that, Includes the following steps: S1. At room temperature, pigment and dispersant are dispersed in water and stirred. After a period of time, a mixture is obtained. The dispersant has an aromatic structure. The dispersant includes at least one of amino acid-modified lignin-based hyperdispersant, NNO, and OP-10. S2. Add the above mixture and grinding balls to a sand mill jar for grinding. After grinding for a certain period of time, filter and separate the grinding balls to obtain water-based pigment paste. S3. Take a certain amount of adhesive and mix it with the above-mentioned water-based pigment paste, and add deionized water to mix evenly to obtain a water-based pigment paste / adhesive mixture. The adhesive is water-based polyurethane emulsion WPU with an average particle size of 38nm. S4. Mix the above-mentioned water-based pigment paste / binder mixture and thickener solution, and add deionized water to mix evenly to obtain a nano-coating paste with a particle size similar to that of the binder; the content of the binder in the nano-coating paste is 15-30wt%, and the content of the water-based pigment paste is 3-6wt%.

2. The method for preparing nano-coating color paste by synergistic dispersion of dispersant and binder according to claim 1, characterized in that, In step S1, the mass ratio of the pigment to the dispersant is 2-6:1; the solid content of the mixture is 1.5-5 wt%.

3. The method for preparing nano-coating color paste by synergistic dispersion of dispersant and binder according to claim 1, characterized in that, In step S2, the grinding balls include at least one of zirconium oxide beads and alumina beads; the particle size of the grinding balls is 0.3-1.0 mm.

4. The method for preparing nano-coating color paste by synergistic dispersion of dispersant and binder according to claim 1, characterized in that, In step S2, the mass ratio of the mixture to the grinding balls is 3-6:10-20; the grinding speed is 1200-1800 rpm, and the grinding time is 6-24 hours.

5. The method for preparing nano-coating color paste by synergistic dispersion of dispersant and binder according to claim 1, characterized in that, In step S3, the mixing process specifically involves ultrasonication at a power of 50-200W for 5-20 minutes.

6. The method for preparing nano-coating color paste by synergistic dispersion of dispersant and binder according to claim 1, characterized in that, In step S4, the amount of thickener used in the thickener solution is 1.5-3.5 wt% of the total mass of the nano-coating pigment.

7. The method for preparing nano-coating color paste by synergistic dispersion of dispersant and binder according to claim 1, characterized in that, In step S4, the thickener in the thickener solution includes at least one of sodium alginate, gelatin, gum arabic, carrageenan, β-cyclodextrin, and sodium carboxymethyl cellulose.

8. A method for preparing a printed fabric, characterized in that, The nano-coating pigment paste prepared by synergistic dispersion of a dispersant and a binder according to any one of claims 1-7 is used to screen print on the fabric, and the printed fabric is obtained by drying and baking.

9. A method for preparing a printed fabric according to claim 8, characterized in that, The screen printing adopts a warp-direction scraping method; the baking temperature is 50-170℃ and the time is 60-120s.

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