Polyester fabric and reduction-cleaning-free ink-jet printing method thereof

Abstract

The invention provides a polyester fabric and a reduction-cleaning-free ink-jet printing method thereof, relates to the field of textile ink-jet printing and also relates to the field of textile manufacturing. The method is used for direct jet printing of the polyester fabric with high-temperature disperse dye ink, specifically, the polyester fabric is pretreated with a pretreating agent containing guanidine salt as a main component, guanidine salt can remarkably reduce mobility of disperse dye in disperse ink, ink droplets jet-printed on the polyester fabric cannot permeate along capillary of the fabric, and therefore the polyester fabric can be directly jet-printed. And the jet printing pattern is clear. Meanwhile, after the polyester fabric treated by the pretreatment agent with guanidine salt as the main component is directly sprayed with high-temperature disperse dye ink for printing, baking and color development, the printed polyester fabric does not need to be subjected to reduction cleaning and water washing, the fastness meets the national standard, and water saving and emission reduction are achieved.

Description

Technical Field

[0001] This invention relates to the field of inkjet printing of textiles, and also to the field of textile manufacturing, and particularly to a polyester fabric and a method for inkjet printing of the fabric without the need for reduction cleaning. Background Technology

[0002] Currently, digital inkjet printing on polyester fabrics mostly involves first digitally printing a transfer printing paper, and then transferring the pattern from the transfer printing paper to the polyester fabric using the sublimation properties of disperse dyes under heat and pressure. The disperse dye inks used in transfer printing are low-temperature or medium-temperature inks, resulting in poor color sublimation fastness. Furthermore, because the heat transfer process requires a certain amount of pressure, it can easily cause fabrics with hollow layers to flatten, thus losing the fabric's unique three-dimensional effect.

[0003] Digital direct-to-garment printing, a type of inkjet printing, involves directly spraying ink onto polyester fabric. The ink used is a high-temperature disperse dye ink, resulting in high heat sublimation fastness of the printed product. Furthermore, direct-to-garment printing only requires high-temperature baking for color development, without affecting the fabric's texture or three-dimensional effect. However, high-temperature disperse dyes are insoluble in water, and their dispersion effect comes from the added dispersant, typically anionic dispersants. Polyester fibers are hydrophobic, causing ink droplets to diffuse along capillary channels upon impact with the fabric, leading to inkjet printing pattern bleeding.

[0004] Current practice dictates that pretreatment is required before inkjet printing. Common pretreatment materials include sodium alginate and hydroxymethyl cellulose, which prevent ink diffusion and ensure the clarity of direct-to-garment printing. However, these materials must be washed off after dyeing, otherwise they will affect the feel and color fastness of the product, and will also generate printing wastewater. Summary of the Invention

[0005] The present invention aims to provide an inkjet printing method that eliminates the need for reduction cleaning; and to provide a polyester fabric. This printing method eliminates the traditional reduction cleaning step, and the resulting polyester fabric not only has clear and three-dimensional printing, but also has a good hand feel and color fastness.

[0006] Firstly, this application provides an inkjet printing method that eliminates the need for reduction cleaning:

[0007] 1. A method for inkjet printing without reduction cleaning, comprising the following preparation process:

[0008] 1) Polyester fabric impregnation pretreatment agent, with a liquid retention rate of 50-90%;

[0009] 2) Drying and shaping at 170-190℃;

[0010] 3) Printing high-temperature dispersion inks containing anionic dispersants;

[0011] 4) Drying;

[0012] 5) Baking at 170-190℃ to develop color, resulting in polyester fabrics that do not require reduction washing;

[0013] The pretreatment agent, by weight, comprises 0.5 to 3 parts of guanidine salt, 0.03 to 1 part of β-cyclodextrin, 1 to 3 parts of pH adjuster, 0.5 to 1 part of nonionic thickener, and 88 to 98 parts of water.

[0014] After the polyester fabric is impregnated with the pretreatment agent, the positively charged guanidine salts adhere to the polyester fabric. After high-temperature disperse ink is sprayed, the guanidine salts and the anionic dispersant combine through electrostatic interaction, neutralizing their negative charge and destroying the electrostatic stability layer of the pigment particles. The pigment particles in the high-temperature disperse ink aggregate due to the loss of charge repulsion, reducing ink diffusion and making it easier to fix to the fiber at high temperatures, thus improving the clarity and color fastness of the pattern.

[0015] The hydrophobic cavities of cyclodextrin selectively encapsulate hydrophobic groups (such as carbon chains) in dispersants, disrupting their steric hindrance and preventing the dispersant from effectively adsorbing onto the pigment surface. Due to the larger vacuoles of disperse dyes, cyclodextrin has a poorer encapsulation effect on disperse dyes compared to anionic dispersants. At high temperatures, the adsorption between the pigment and the substrate is enhanced, and the disrupted pigment rapidly deposits and fixes onto the substrate surface, forming a pattern with high clarity and high color fastness. In this application, the contents of guanidine salt, β-cyclodextrin, and nonionic thickener are appropriate and in small quantities, eliminating the need for additional water washing steps to remove residual dispersants. The deposits formed on polyester fabrics and / or pretreatment agents have a strong effect on the dye, and β-cyclodextrin has a certain binding effect on unfixed dyes. Therefore, the dye is more fully combined with the fabric, eliminating the need for traditional reduction washing.

[0016] Furthermore, the content of the β-cyclodextrin is 0.05-0.5 parts of β-cyclodextrin.

[0017] Furthermore, the high-temperature disperse ink contains 20-40 wt% disperse dye and 0.3-5 wt% anionic dispersant.

[0018] Furthermore, the anionic dispersant includes one of sodium lignosulfonate, sodium dodecylbenzenesulfonate (SDBS), dispersant CNF, and NNO.

[0019] Furthermore, the preferred anionic dispersants are SDBS and sodium lignosulfonate; this may be because β-cyclodextrin has a good inclusion effect on SDBS and sodium lignosulfonate, and SDBS and sodium lignosulfonate have good dispersing properties, resulting in better clarity and color fastness; the poor effect of CNF may be due to the weaker inclusion ability of β-cyclodextrin on NNO and CNF.

[0020] Furthermore, the anionic dispersant is NNO, and the β-cyclodextrin is β-cyclodextrin with a content of 0.05-0.5 parts.

[0021] Further, the β-cyclodextrin is hydroxypropyl β-cyclodextrin. Further, the guanidine salt includes one or a combination of several of the following: polyhexamethylene guanidine hydrochloride, polyhexamethylene biguanide hydrochloride, polyhexamethylene guanidine phosphate, polyhexamethylene guanidine sulfate, polyhexamethylene guanidine p-hydroxybenzoate, polyhexamethylene guanidine stearate, polytetramethylene guanidine hydrochloride, and polyoctamethylene guanidine hydrochloride; the pH adjuster includes citric acid and / or oxalic acid; the nonionic thickener includes one or a combination of several of the following: polyethylene glycol, polyethylene oxide, hydroxyethyl cellulose, polyacrylamide, natural polysaccharide thickeners, and polyurethane thickeners.

[0022] Furthermore, the pretreatment agent also includes 0.01-0.1 parts of antioxidants, including Irganox 1010, Irganox 1330, Cyanox 1790 and BASF Irganox 1076.

[0023] Furthermore, the preferred antioxidants are Irganox 1010 and / or Irganox 1330.

[0024] Irganox 1010, with its tetrasubstituted hindered phenol structure, has a large molecular volume and significant steric hindrance, making it difficult to enter the β-cyclodextrin cavity and exhibiting poor polar compatibility with the hydrophobic β-cyclodextrin cavity. Irganox 1330, with its trisubstituted phenol structure, may still have significant steric hindrance and a low inclusion effect, resulting in a lower degree of shielding of the active sites of antioxidants by the inclusion of β-cyclodextrin, thus improving the anti-yellowing properties of polyester fabrics. The poor anti-yellowing properties of antioxidants BASF's Irganox 1076 and Cyanox 1790 may be due to their monosubstituted phenol structure or smaller steric hindrance, which leads to better compatibility with the β-cyclodextrin cavity, resulting in greater shielding of the active sites of antioxidants and thus poorer antioxidant performance.

[0025] Secondly, this application provides a polyester fabric:

[0026] The polyester fabric was obtained using the inkjet printing method of this application that eliminates the need for reduction cleaning.

[0027] Beneficial effects: 1. The method of this application is used for direct printing of polyester fabrics with high-temperature disperse dye inks. Specifically, the polyester fabric is pretreated with a pretreatment agent containing guanidine salt as the main component. Guanidine salt can significantly reduce the mobility of disperse dyes in disperse inks, and the ink droplets printed on it will not spread along the capillary of the fabric, making the printed pattern clear. At the same time, after the polyester fabric treated with the guanidine salt as the main component is baked and developed by direct printing of high-temperature disperse dye inks, the printed polyester fabric does not require reduction washing and water washing, and the fastness meets the national standards, thus achieving water conservation and emission reduction.

[0028] 2. Furthermore, the dosage of β-cyclodextrin and the use of NNO as the anionic dispersant in the high-temperature dispersion ink were optimized, which enabled β-cyclodextrin to better encapsulate the anionic dispersant, thereby further improving the clarity and color fastness of the pattern.

[0029] 3. Furthermore, an antioxidant is used in the pretreatment agent, and the type of antioxidant is preferred to reduce the possibility of yellowing of the raw materials in the pretreatment agent under high temperature during the preparation process, which would cause the polyester fabric to yellow; further optimization of the type of antioxidant improves the anti-yellowing property of the polyester fabric. Detailed Implementation

[0030] To make the technical solution of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments.

[0031] Example 1: A method for inkjet printing without reduction cleaning, comprising the following preparation steps:

[0032] 1) Polyester grey fabric (85 g / m², 100% polyester four-way stretch) is pretreated with a pre-treatment agent after one dip-in and one dip-out process on a padding machine, with a liquid retention rate of 50%;

[0033] 2) Next, it is dried and shaped at 180℃ using a hot air tenter frame;

[0034] 3) Digital direct-to-garment printing uses high-temperature dispersion ink containing anionic dispersants. The amount of high-temperature dispersion ink used is 15 mL / m² (the amount of ink used can be selected within the range of 1-20 mL / m² according to actual needs).

[0035] 4) Drying (150℃, 1 min);

[0036] 5) Use a hot air baking machine to bake and develop the color (180℃, 6 min) to obtain polyester fabrics that do not require reduction washing;

[0037] The pretreatment agent, by weight, comprises 0.5 to 3 parts of guanidine salt, 0.03 to 1 part of β-cyclodextrin, 1 to 3 parts of pH adjuster, 0.5 to 1 part of nonionic thickener, and 88 to 98 parts of water.

[0038] The high-temperature disperse dye comprises 10 wt% disperse dye (particle size 100 nm, Disperse Blue 79), 2 wt% anionic dispersant (specifically sodium dodecylbenzenesulfonate), 20 wt% organic solvent (specifically ethylene glycol), 1.5 wt% nonionic surfactant (specifically X-100), 0.3 wt% Dow Corning silicone defoamer ACP-0544 (0.05-0.3%), pH adjuster citric acid (adjusting pH to 8), 0.1 wt% antioxidant Irganox 1010, and the balance being water.

[0039] Disperse dyes, anionic dispersants, and a portion of organic solvent / water are mixed and processed using zirconium bead milling or a circulating sand mill until the dye particle size is ≤150nm and PDI ≤0.3. The remaining solvent, surfactant, and additives are added and homogenized by low-speed stirring. The mixture is then filtered through a 0.45μm microporous membrane to ensure ink cleanliness and printhead suitability.

[0040] Examples 2 to 5 describe an inkjet printing method that does not require reduction cleaning. The difference between this method and Example 1 lies in the different preparation process parameters and the types and weights of raw materials used in the pretreatment agent, as detailed in Table 1.

[0041] Table 1. List of process parameters, types of raw materials used in pretreatment agents, and weight settings in the inkjet printing methods of Examples 1 to 5.

[0042]

[0043] Among them, hydroxyethyl cellulose has an average molecular weight of 200,000, and sodium lignosulfonate has an average molecular weight of 10,000.

[0044] Example 6, an inkjet printing method that does not require reduction cleaning, differs from Example 1 in that sodium dodecylbenzenesulfonate is replaced by an equal amount of dispersant NNO in the high-temperature disperse ink.

[0045] Example 7, an inkjet printing method that does not require reduction cleaning, differs from Example 1 in that sodium dodecylbenzenesulfonate is replaced by an equal amount of dispersant CNF in the high-temperature disperse ink.

[0046] Example 8, an inkjet printing method that does not require reduction cleaning, differs from Example 1 in that 1 part by mass of β-cyclodextrin is used in the pretreatment agent.

[0047] Example 9, an inkjet printing method that does not require reduction cleaning, differs from Example 1 in that 0.5 parts by weight of β-cyclodextrin are used in the pretreatment agent.

[0048] Example 10, an inkjet printing method without reduction cleaning, differs from Example 1 in that 0.03 parts by weight of β-cyclodextrin is used in the pretreatment agent.

[0049] Example 11, an inkjet printing method without reduction cleaning, differs from Example 1 in that the pretreatment agent also includes 0.1 parts by weight of the antioxidant Irganox 1010.

[0050] Example 12, an inkjet printing method that does not require reduction cleaning, differs from Example 1 in that the pretreatment agent also includes 0.1 parts by weight of the antioxidant BASF Irganox 1076.

[0051] Comparative Example 1, an inkjet printing method that does not require reduction cleaning, differs from Example 1 in that polyhexamethylene guanidine hydrochloride is not used in the pretreatment agent.

[0052] Comparative Example 2, an inkjet printing method that does not require reduction cleaning, differs from Example 1 in that hydroxypropyl β-cyclodextrin is not used in the pretreatment agent.

[0053] Comparative Example 3, an inkjet printing method that does not require reduction cleaning, differs from Example 1 in that the pretreatment agent includes 2 parts by mass of sodium alginate, 1 part by mass of citric acid, and 97 parts by mass of deionized water.

[0054] Comparative Example 4, an inkjet printing method that does not require reduction cleaning, differs from Example 1 in that the pretreatment agent includes 2 parts by weight of sodium alginate, 1 part by weight of citric acid, and 97 parts by weight of deionized water; and a reduction cleaning step is used after baking and color development.

[0055] The reducing cleaning solution contains 2 g / L sodium hydrosulfite and 1 g / L caustic soda.

[0056] Restoration cleaning process: Place the baked and dyed polyester in an overflow dyeing machine, heat it to 70~80℃ at 2℃ / min, keep it warm for 20 minutes, then wash it with 60℃ hot water for 10 minutes, and finally wash it with room temperature water until neutral.

[0057] Performance testing:

[0058] The color fastness to washing with soap was tested according to GB / T 3921-2008, the color fastness to dry cleaning was tested according to GB / T 5711-2015, the color fastness to rubbing was tested according to GB / T 3920-2008, the color fastness to light was tested according to Method 3 of GB / T 8427-2019, the color fastness to perspiration was tested according to GB / T 3922-2013, and the color fastness to water was tested according to GB / T 5713-2013. The test results are shown in Table 2.

[0059] Table 2. List of test data for polyester fabrics obtained using the methods of Examples 1 to 12 and Comparative Examples 1 to 4

[0060]

[0061] The test results of rubbing fastness and sweat resistance of Example 1 are better than those of Example 6 and Example 7. The test results of rubbing fastness and sweat resistance of Example 6 are better than those of Example 7. This may be because the hydrophobic cavity of cyclodextrin selectively includes the hydrophobic groups (such as carbon chains) in the dispersant. The inclusion effect of sodium dodecylbenzenesulfonate > dispersant NNO, dispersant NNO > dispersant CNF. The inclusion effect of cyclodextrin on the dispersant is worse, which affects the interaction force between the disperse dye and the substrate, resulting in poorer adhesion, clarity and color fastness.

[0062] The experimental results of washing performance, rubbing fastness and sweat resistance of Examples 1 and 9 are better than those of Examples 8 and 10, indicating that the optimal amount of β-cyclodextrin further improves the clarity of the pattern and color fastness. It is possible that because the content of β-cyclodextrin is higher, it affects the bonding between the disperse dye and the base fabric, while the content of β-cyclodextrin is lower, resulting in a poorer encapsulation effect on the anionic dispersant.

[0063] Anti-yellowing performance test: Using a colorimeter, under whiteness measurement conditions, randomly measure different parts (8 points) of the sample, calculate the average value, and record it as the initial whiteness. In a UV aging apparatus using a D65 light source, aging for 10 hours each time, repeated 10 times. After aging, use a colorimeter to randomly measure 8 points in the same manner, calculate the average value, and record it as the test whiteness. Calculate the color difference value between the test whiteness and the initial whiteness to evaluate the anti-yellowing performance. The lower the color difference value, the stronger the anti-yellowing ability.

[0064]

[0065] The anti-yellowing performance of Example 11 is better than that of Example 12, possibly because the molecular volume of Irganox 1010 is larger and its steric hindrance is significant, making it difficult to be completely encapsulated by β-cyclodextrin, resulting in a lower degree of shielding of its active sites (such as phenolic hydroxyl groups). In contrast, the Irganox 1076 used in Example 12 has a smaller molecular steric hindrance, better compatibility with the β-cyclodextrin cavity, and a higher encapsulation rate. However, its active sites are excessively shielded, which reduces the effective role of the antioxidant in polyester.

[0066] This indicates that the use of antioxidants in the pretreatment agent results in better anti-yellowing properties of the obtained polyester fabrics during the preparation and use processes.

[0067] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, 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 modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A method for inkjet printing without the need for reduction cleaning, characterized in that, The preparation process includes the following: 1) Polyester fabric impregnation pretreatment agent, with a liquid retention rate of 50-90%; 2) Drying and shaping at 170-190℃; 3) Printing high-temperature dispersion inks containing anionic dispersants; 4) Drying; 5) Baking at 170-190℃ to develop color, resulting in polyester fabrics that do not require reduction washing; The pretreatment agent, by weight, comprises 0.5-3 parts of guanidine salt, 0.03-1 parts of β-cyclodextrin, 1-3 parts of pH adjuster, 0.5-1 parts of nonionic thickener, and 88-98 parts of water.

2. The inkjet printing method for non-reduction cleaning according to claim 1, characterized in that, The content of the β-cyclodextrin is 0.05-0.5 parts.

3. The inkjet printing method for non-reduction cleaning according to claim 1 or 2, characterized in that, The high-temperature disperse ink contains 20-40 wt% disperse dye and 0.3-5 wt% anionic dispersant.

4. The inkjet printing method for non-reduction cleaning according to claim 3, characterized in that, The anionic dispersant includes one of sodium lignosulfonate, sodium dodecylbenzenesulfonate, dispersant CNF, and NNO.

5. The method for printing ink without reducing and cleaning according to claim 4, characterized in that, The anionic dispersant is sodium dodecylbenzenesulfonate, and the β-cyclodextrin is β-cyclodextrin in a content of 0.05-0.5 parts.

6. The inkjet printing method for non-reduction cleaning according to claim 5, characterized in that, The β-cyclodextrin is hydroxypropyl β-cyclodextrin.

7. A method for inkjet printing without reduction cleaning according to any one of claims 1, 2, 4, and 6, characterized in that, The guanidine salts include one or a combination of several of the following: polyhexamethylene guanidine hydrochloride, polyhexamethylene biguanidine hydrochloride, polyhexamethylene guanidine phosphate, polyhexamethylene guanidine sulfate, polyhexamethylene guanidine p-hydroxybenzoate, polyhexamethylene guanidine stearate, polytetramethylene guanidine hydrochloride, and polyoctamethylene guanidine hydrochloride.

8. The inkjet printing method for non-reduction cleaning according to claim 7, characterized in that, The pH adjuster includes citric acid and / or oxalic acid; the nonionic thickener includes one or a combination of polyethylene glycol, polyethylene oxide, hydroxyethyl cellulose, polyacrylamide, natural polysaccharide thickeners, and polyurethane thickeners.

9. A method for inkjet printing without reduction cleaning according to any one of claims 1, 2, 4, 6, and 8, characterized in that, The pretreatment agent also includes 0.01-0.1 parts of an antioxidant, wherein the antioxidant is Irganox 1010 and / or Irganox 1330.

10. Polyester fabric obtained by the inkjet printing method of claim 9 that does not require reduction cleaning.

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