Pretreatment-free ink and application thereof

Abstract

The invention provides pretreatment-free ink and application thereof. The ink comprises the following components in parts by mass: 0.2 to 2 parts of a photosensitive cross-linking agent, 8 to 30 parts of film-forming resin and 15 to 25 parts of a coloring agent, and the content of the photosensitive cross-linking agent is 0.2 to 2 parts, the content of the film-forming resin is 8 to 30 parts, and the content of the coloring agent is 15 to 25 parts. The photosensitive cross-linking agent is introduced into the ink, so that a compact cross-linked network can be quickly formed through illumination after ink-jet printing, and the color blocking effect is remarkably improved while good printing fluency is ensured. The photosensitive cross-linking agent and the film-forming resin have a synergistic effect to form a compact film, and the film can firmly limit the coloring agent in a film layer in an extremely short time, so that the migration and extrusion phenomena of the coloring agent in the film-forming process are greatly inhibited, and the coloring agent is ensured to be uniformly distributed on the surface of a fabric and is effectively prevented from permeating into fibers.

Description

Technical Field

[0001] This invention relates to the field of coating inks, and more specifically to a pretreatment-free ink and its application. Background Technology

[0002] With the widespread application of digital direct-to-garment (DGD) technology in textiles, the market demand for pigment inks in home textiles, apparel, and other fields is constantly growing. Traditional pigment inks typically require a pretreatment solution to improve the surface properties of the fabric before printing, in order to achieve good color blocking and effectively prevent the pigment in the ink from penetrating into the fiber, resulting in bright colors and clear boundaries. The pretreatment process not only increases production steps and reduces production efficiency but also increases manufacturing and environmental costs. Pretreatment-free pigment inks have emerged to address this need. To achieve excellent color blocking, pretreatment-free inks often require the addition of a high proportion of film-forming resin or specific functional additives to the formulation, allowing the ink to quickly form a dense film after being sprayed onto the fabric surface, effectively locking the pigment onto the fabric surface. However, while improving color blocking performance, this can easily lead to increased ink system viscosity and poorer rheological properties, affecting its smoothness in the printhead, increasing the risk of printhead clogging, and reducing the industrial applicability of continuous printing.

[0003] In view of this, there is an urgent need to develop high-quality inks that do not require pretreatment and are suitable for inkjet printing processes. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a pretreatment-free ink and its application.

[0005] In a first aspect, the present invention provides an ink that requires no pretreatment, comprising, by weight parts, 0.2 to 2 parts of a photosensitive crosslinking agent, 8 to 30 parts of a film-forming resin, and 15 to 25 parts of a colorant.

[0006] This ink, by introducing a photosensitive crosslinking agent, can rapidly form a crosslinked network under light after inkjet printing. This significantly improves color blocking while ensuring smooth printing. After the ink forms a pattern on the fabric surface, it effectively prevents the pigment from penetrating into the fiber interior, achieving a vibrant color and clearly defined pattern effect. The photosensitive crosslinking agent works synergistically with the film-forming resin to form a dense film. This film can firmly confine the colorant within the film layer in a very short time, greatly inhibiting the migration and extrusion of the colorant during film formation, ensuring uniform distribution of the colorant on the fabric surface and effectively preventing its penetration into the fiber interior. Simultaneously, because the photosensitive crosslinking agent does not react before ink jetting, it does not increase the viscosity of the ink system, thus ensuring smooth printing.

[0007] Furthermore, the mass ratio of the photosensitive crosslinking agent to the film-forming resin ranges from 1:8 to 1:40, preferably from 1:15 to 1:30; the mass ratio of the film-forming resin to the colorant ranges from 1:0.72 to 1:3.03, preferably from 1:0.83 to 1:1.33.

[0008] Furthermore, the photosensitive crosslinking agent is a photocrosslinkable acrylate additive, which can be selected from aqueous polyacrylates or photosensitive resins containing photoinitiators; the content of the photosensitive crosslinking agent can be, but is not limited to, 0.2 parts, 0.5 parts, 0.8 parts, 1.0 parts, 1.2 parts, 1.5 parts, 1.8 parts, and 2.0 parts. The photocrosslinkable acrylate additive has good water dispersibility and photosensitivity, and can rapidly undergo a crosslinking reaction under ultraviolet light irradiation to form a dense network structure, effectively improving the ink's color blocking performance. The photosensitive resin is a type of polymer material that can be rapidly cured through a photochemical reaction under ultraviolet light (300~500 nm) or visible light of a specific wavelength; for example, the photocrosslinkable acrylate additive is an aqueous polyacrylate containing 1% photoinitiator. The photoinitiator can include at least one of BP (benzophenone), ITX (isopropylthioxanthone), and DMPA (2,2-dimethoxy-2-phenylacetophenone).

[0009] Furthermore, the film-forming resin can be selected from waterborne nano-polyurethane resins, such as TAKELAC W-5661 or R130; the content of the film-forming resin can be, but is not limited to, 8 parts, 12 parts, 16 parts, 20 parts, 23 parts, 25 parts, 28 parts, or 30 parts. Waterborne nano-polyurethane resins possess good film-forming properties and flexibility. Synergistically, with photocrosslinkable acrylate additives, they can form a denser and more uniform film, effectively improving the ink's color-blocking effect and adhesion.

[0010] Furthermore, the colorant can be selected from water-based nano-pigment pastes, such as CAB-O-JET 250C or SP900BK. The content of the colorant can be, but is not limited to, 15 parts, 18 parts, 20 parts, 22 parts, 23 parts, 24 parts, or 25 parts. Water-based nano-pigment pastes have good dispersibility and color performance, and can provide bright and stable color effects.

[0011] Furthermore, the ink also contains 25-40 parts of polyol, 2-10 parts of humectant, 0.1-5 parts of surfactant, 0.1-5 parts of defoamer, 0.1-2 parts of bactericide, and 10-20 parts of deionized water. The mass of deionized water is at least 1.5 times that of the humectant, and the mass ratio of deionized water to polyol is 1:(1.5-2.61). Increasing the polyol content can improve the solubility and dispersion stability of the photosensitive crosslinking agent in the ink system. As a co-solvent, the polyol promotes the compatibility of the photosensitive component with the film-forming resin. An appropriate alcohol-to-water ratio helps control the spreading and penetration of the ink on the fabric. The presence of polyol can regulate the crosslinking reaction rate, avoiding surface wrinkling caused by excessively rapid crosslinking. Setting the ratio of humectant to deionized water ensures the sufficient dissolution of the humectant. The polyols can be selected from pentaerythritol, neopentyl glycol, ethylene glycol, 1,2-propanediol, etc., and their contents can be selected from, but are not limited to, 25 parts, 28 parts, 30 parts, 32 parts, 35 parts, and 40 parts; the humectants can be selected from betaine, trehalose, erythritol, urea, etc., and their contents can be selected from, but are not limited to, 2 parts, 3 parts, 5 parts, 7 parts, and 10 parts; the surfactants can be selected from BYKJET-9131, SURFYNOL 104 PA, etc., and their contents can be selected from, but are not limited to, 0.1 parts, 0.5 parts, 1 part, 2 parts, and 5 parts; the defoamers can be selected from TEGO Foamex 825, etc., and their contents can be selected from, but are not limited to, 0.1 parts, 0.5 parts, 1 part, 2 parts, and 5 parts; the bactericides can be selected from Protectol PE, etc., and their contents can be selected from, but are not limited to, 0.1 parts, 0.2 parts, 0.5 parts, 1 part, and 2 parts.

[0012] Furthermore, the mass ratio of film-forming resin to (polyol + humectant + deionized water) is 1:14-1:8.3, preferably 1:2.08-1:4; the mass ratio of crosslinking agent to (polyol + humectant + deionized water) is 1:21-1:333, preferably 1:33-1:67.

[0013] Secondly, this invention provides an application of the aforementioned ink. After inkjet printing the ink onto the surface of a textile fabric, it is irradiated under a UV lamp for 0.5-2 minutes, causing the photosensitive crosslinking agent to undergo a crosslinking reaction and form an interpenetrating network structure with the film-forming resin. This application method, through inkjet printing followed by light irradiation, enables the ink to rapidly form a dense film on the fabric surface. This film can firmly confine the colorant within the film layer in a very short time, greatly suppressing the migration and extrusion of the colorant during the film-forming process. This ensures that the colorant is evenly distributed on the fabric surface and effectively prevents it from penetrating into the fiber interior, thereby effectively improving the color blocking effect without affecting the printing smoothness of the ink.

[0014] Furthermore, the wavelength of the ultraviolet lamp is 300-500nm, such as a 395nm LED UV lamp, and the power is 50-100mW / cm². 2 The irradiation time is from 30 seconds to 2 minutes, for example, 60 seconds. Ultraviolet light in this wavelength range can effectively excite the photoinitiator in the photosensitive crosslinking agent, promoting the crosslinking reaction and forming a dense network structure. Specifically, the ultraviolet lamp can be a 395nm LED UV lamp, and the power can be selected from 50 mW / cm². 2 60 mW / cm 2 80 mW / cm 2 100 mW / cm 2 The irradiation time can be any value selected from 30 seconds, 45 seconds, 60 seconds, 90 seconds, and 120 seconds.

[0015] The present invention has the following beneficial effects: 1. This invention introduces a photosensitive crosslinking agent and employs post-spray light treatment, enabling the ink to rapidly undergo a crosslinking reaction after being sprayed onto the fabric surface, forming a dense film that effectively prevents colorant penetration and effectively resolves the contradiction between color blocking performance and printing smoothness in traditional pretreatment-free inks.

[0016] 2. The photosensitive crosslinking agent of the present invention does not react before ink jetting and does not increase the viscosity of the ink system, thereby ensuring the smoothness of ink printing and printhead compatibility, reducing the risk of printhead clogging, and enabling the ink to pass smoothly through the printhead during inkjet printing without clogging or needle breakage.

[0017] 3. The dense film layer formed by photocrosslinking in this invention can firmly confine the colorant within the film layer, greatly suppressing the migration and extrusion of the colorant during film formation, improving color vibrancy and fastness, and achieving excellent color blocking performance. The ink formulation of this invention is reasonable, the preparation process is simple, and it is suitable for inkjet printing on various textile fabrics, showing good prospects for industrial applications. Detailed Implementation

[0018] To facilitate understanding of this application, a more complete description will be provided below. This application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0019] In some preferred embodiments, the polyol may be selected from one or more of pentaerythritol, neopentyl glycol, ethylene glycol, 1,2-propanediol, and glycerin; the content of the polyol may be selected from 25 parts, 28 parts, 30 parts, 32 parts, 35 parts, and 40 parts. In some preferred embodiments, the humectant may be selected from one or more of betaine, trehalose, erythritol, and urea; the content of the humectant may be selected from 2 parts, 3 parts, 5 parts, 7 parts, and 10 parts.

[0020] In some preferred embodiments, the surfactant may be selected from BYKJET-9131 and SURFYNOL 104PA; the surfactant content may be selected from 0.1 parts, 0.5 parts, 1 part, 2 parts, and 5 parts. In some preferred embodiments, the defoamer may be selected from TEGO Foamex 825; the defoamer content may be selected from 0.1 parts, 0.5 parts, 1 part, 2 parts, and 5 parts. In some preferred embodiments, the bactericide may be selected from Protectol PE; the bactericide content may be selected from 0.1 parts, 0.2 parts, 0.5 parts, 1 part, and 2 parts.

[0021] In some preferred embodiments, the aqueous nano-polyurethane resin can be selected from either TAKELAC W-5661 or R130; the content of the aqueous nano-polyurethane resin can be selected from any one of 8 parts, 12 parts, 15 parts, 20 parts, 25 parts, or 30 parts. The aqueous nano-polyurethane resin, with a particle size in the nanoscale, is an aqueous polyurethane dispersion that can provide excellent film-forming properties and flexibility. The nano-polyurethane resin has a smaller particle size and a larger specific surface area, which can form a denser and more uniform film, thereby improving the color blocking effect and adhesion of the ink.

[0022] In some preferred embodiments, the aqueous nano-pigment paste can be selected from either CAB-O-JET 250C or SP900BK; the content of the aqueous nano-pigment paste can be selected from any one of 15 parts, 18 parts, 20 parts, 22 parts, 23 parts, 24 parts, or 25 parts. In some preferred embodiments, the photocrosslinkable acrylate additive can be selected from aqueous polyacrylate or photosensitive resin containing a photoinitiator; the content of the photocrosslinkable acrylate additive can be selected from any one of 0.2 parts, 0.5 parts, 1 part, 1.5 parts, or 2 parts. In some preferred embodiments, the wavelength of the ultraviolet lamp can be arbitrarily selected between 300, 350, 395, 450, and 500 nm, and the power can be 50, 60, 80, or 100 mW / cm². 2 You can choose any of the options, and the irradiation time can be selected arbitrarily between 30, 45, 60, 90, and 120 seconds.

[0023] Example 1: This example provides a pretreatment-free ink and a method for applying the ink.

[0024] The raw materials for ink preparation include: polyol (neopentyl glycol, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., content 30 parts), humectant (erythritol, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., content 5 parts), surfactant (BYKJET-9131, purchased from BYK Chemical, content 1 part), defoamer (TEGO Foamex 825, purchased from Evonik Industries, content 0.5 parts), bactericide (Protectol PE, purchased from Lanxess Chemical, content 0.2 parts), waterborne nano-polyurethane resin (TAKELAC W-5661, purchased from Mitsui Chemicals, content 20 parts), waterborne nano-pigment paste (CAB-O-JET250C, purchased from Cabot Corporation, content 23 parts), and photocrosslinkable acrylate additives (waterborne polyacrylate containing 10wt% photoinitiator (DMPA, CAS No.: 24650-42-8), BASF PA). 4560, waterborne polyacrylate content 1 part (the same waterborne polyacrylate was used in the following examples and comparative examples), deionized water (content 19.3 parts).

[0025] The ink preparation method includes: weighing all components according to the proportion, first adding polyol, humectant, surfactant, defoamer, bactericide, and deionized water to a 5000 mL dispersion tank, stirring at low speed for 10 min, then adding water-based nano-polyurethane resin and increasing the speed to 600 rpm and stirring for another 10 min, then adding water-based nano-pigment paste and increasing the speed to 1000 rpm and stirring for 30 min, finally adding photocrosslinkable acrylate additives and stirring for another 5 min, filtering once with 0.45 μm and once with 0.22 μm filter membranes (0.05 MPa), and then defoaming under negative pressure (0.05 MPa) until no bubbles are present, to obtain the final ink.

[0026] The ink application method includes: adding ink to the Kyocera QA printhead HM-1800B-K24 machine. Ambient temperature 20-35℃, humidity 55-75%, and the following parameters: negative pressure -5.5kPa, doctor blade negative pressure -5.0kPa, carriage speed 1.2 m / s, voltage 22.5V, printhead temperature 30℃, print height 3.5 mm, ink volume set to 90%, resolution 600×1200, waveform HM_K32_20200831, printing a pure yellow block (1.20 m × 0.50 m, length 100 m) onto untreated woven fabric, and immediately after printing under a 395 nm LED UV lamp (100 mW / cm²). 2 Irradiate for 60 seconds.

[0027] Example 2: This example provides a pretreatment-free ink and a method for applying the ink.

[0028] The raw materials for ink preparation include: polyol (pentaerythritol, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., content 25 parts), humectant (betaine, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., content 2 parts), surfactant (SURFYNOL 104 PA, purchased from Air Products, content 0.1 parts), defoamer (TEGO Foamex 825, purchased from Evonik Industries, content 0.1 parts), bactericide (Protectol PE, purchased from Lanxess Chemical, content 0.1 parts), waterborne nano-polyurethane resin (R130, purchased from Mitsui Chemicals, content 30 parts), waterborne nano-pigment paste (SP900BK, purchased from Cabot Corporation, content 25 parts), photocrosslinkable acrylate additive (content 2 parts), and deionized water (content 15.7 parts). The method for preparing the ink is the same as in Example 1.

[0029] The ink application method includes: adding ink to a Kyocera HM-1800B-K24 printer with a QA printhead. At an ambient temperature of 20-35°C and humidity of 55-75%, print a pure black patch using the same printing parameters as in Example 1. Print onto untreated woven fabric, and immediately after printing, expose to a 395 nm LED UV lamp (50 mW / cm²). 2 Irradiate for 120 seconds.

[0030] Example 3: This example provides a pretreatment-free ink and a method for applying the ink.

[0031] The raw materials for ink preparation include: polyol (1,2-propanediol, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., content 40 parts), humectant (trehalose, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., content 9.5 parts), surfactant (BYKJET-9131, purchased from BYK Chemical, content 5 parts), defoamer (TEGO Foamex 825, purchased from Evonik Industries, content 5 parts), bactericide (Protectol PE, purchased from Lanxess Chemical, content 2 parts), waterborne nano-polyurethane resin (TAKELAC W-5661, purchased from Mitsui Chemicals, content 8 parts), waterborne nano-pigment paste (CAB-O-JET250C, purchased from Cabot Corporation, content 15 parts), photocrosslinkable acrylate additive (photosensitive resin Laromer 9000, purchased from BASF, content 0.2 parts), and deionized water (content 15.3 parts).

[0032] The method for preparing the ink is the same as in Example 1.

[0033] The ink application method includes: adding ink to a Kyocera HM-1800B-K24 printer with a QA printhead. At an ambient temperature of 20-35°C and humidity of 55-75%, print a pure yellow patch using the same printing parameters as in Example 1. Print onto untreated woven fabric, and immediately after printing, expose to a 300 nm LED UV lamp (80 mW / cm²). 2 Irradiate for 30 seconds.

[0034] Example 4: This example provides a pretreatment-free ink and a method for applying the ink.

[0035] The raw materials for ink preparation include: polyol (neopentyl glycol, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., content 34 parts), humectant (erythritol, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., content 7 parts), surfactant (BYKJET-9131, purchased from BYK Chemical, content 2 parts), defoamer (TEGO Foamex 825, purchased from Evonik Industries, content 1 part), bactericide (Protectol PE, purchased from Lanxess Chemical, content 0.5 parts), waterborne nano-polyurethane resin (TAKELAC W-5661, purchased from Mitsui Chemicals, content 15 parts), waterborne nano-pigment paste (CAB-O-JET250C, purchased from Cabot Corporation, content 20 parts), photocrosslinkable acrylate additive (content 0.5 parts), and deionized water (content 20 parts).

[0036] The method for preparing the ink is the same as in Example 1.

[0037] The ink application method includes: adding ink to a Kyocera HM-1800B-K24 printer with a QA printhead. At an ambient temperature of 20-35°C and humidity of 55-75%, print a pure yellow patch using the same printing parameters as in Example 1. Print onto untreated woven fabric, and immediately after printing, expose to a 450 nm LED UV lamp (60 mW / cm²). 2 Irradiate for 90 seconds.

[0038] Example 5: This example provides a pretreatment-free ink and a method for applying the ink.

[0039] The raw materials for ink preparation include: polyol (glycerol, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., content 33 parts), humectant (urea, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., content 3 parts), surfactant (SURFYNOL 104 PA, purchased from Air Products, content 0.5 parts), defoamer (TEGO Foamex 825, purchased from Evonik Industries, content 2 parts), bactericide (Protectol PE, purchased from Lanxess Chemical, content 1 part), waterborne nano-polyurethane resin (R130, purchased from Mitsui Chemicals, content 25 parts), waterborne nano-pigment paste (SP900BK, purchased from Cabot Corporation, content 18 parts), photocrosslinkable acrylate additive (photosensitive resin Laromer 9000, purchased from BASF, content 1.5 parts), and deionized water (content 16 parts).

[0040] The method for preparing the ink is the same as in Example 1.

[0041] The ink application method includes: adding ink to a Kyocera HM-1800B-K24 printer with a QA printhead. At an ambient temperature of 20-35°C and humidity of 55-75%, print a pure yellow patch using the same printing parameters as in Example 1. Print onto untreated woven fabric, and immediately after printing, expose to a 500 nm LED UV lamp (100 mW / cm²). 2 Irradiate for 45 seconds.

[0042] Example 6: This example provides a pretreatment-free ink and a method for applying the ink.

[0043] The raw materials for ink preparation include: polyol (neopentyl glycol, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., content 40 parts), humectant (trehalose, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., content 5 parts), surfactant (BYKJET-9131, purchased from BYK Chemical, content 1 part), defoamer (TEGO Foamex 825, purchased from Evonik Industries, content 0.5 parts), bactericide (Protectol PE, purchased from Lanxess Chemical, content 0.2 parts), waterborne nano-polyurethane resin (TAKELAC W-5661, purchased from Mitsui Chemicals, content 8 parts), waterborne nano-pigment paste (CAB-O-JET250C, purchased from Cabot Corporation, content 24.3 parts), photocrosslinkable acrylate additive (content 1 part), and deionized water (content 20 parts).

[0044] The method for preparing the ink is the same as in Example 1.

[0045] The ink application method includes: adding ink to a Kyocera HM-1800B-K24 printer with a QA printhead. At an ambient temperature of 20-35°C and humidity of 55-75%, print a pure yellow patch using the same printing parameters as in Example 1. Print onto untreated woven fabric, and immediately after printing, expose to a 395 nm LED UV lamp (80 mW / cm²). 2 Irradiate for 60 seconds.

[0046] Comparative Example 1: The ink in this comparative example is basically the same as that in Example 1, except that no photosensitive crosslinking agent is added to the ink in this comparative example. Specifically, the raw materials for preparing the ink in this comparative example include: polyol (neopentyl glycol, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., content 31 parts), humectant (erythritol, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., content 5 parts), surfactant (BYKJET-9131, purchased from BYK Chemical, content 1 part), defoamer (TEGOFoamex 825, purchased from Evonik Industries, content 0.5 parts), bactericide (Protectol PE, purchased from Lanxess Chemical, content 0.2 parts), waterborne nano-polyurethane resin (TAKELAC W-5661, purchased from Mitsui Chemicals, content 20 parts), waterborne nano-pigment paste (CAB-O-JET 250C, purchased from Cabot Corporation, content 23 parts), and deionized water (content 19.3 parts).

[0047] The preparation method of the ink in this comparative example is the same as that in Example 1.

[0048] The ink application method for this comparative example includes: adding ink to a Kyocera HM-1800B-K24 printer with a QA printhead. Under ambient temperatures of 20-35°C and humidity of 55-75%, print a pure yellow patch using the same printing parameters as in Example 1. Print onto untreated woven fabric, and do not subject to post-printing light treatment.

[0049] Comparative Example 2: The ink in this comparative example is basically the same as that in Example 1, except that no photosensitive crosslinking agent is added and the amount of waterborne nano-polyurethane resin is reduced to 8 parts. Specifically, the raw materials for preparing the ink in this comparative example include: polyol (neopentyl glycol, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., content 40 parts), humectant (erythritol, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., content 5 parts), surfactant (BYKJET-9131, purchased from BYK Chemical, content 1 part), defoamer (TEGO Foamex 825, purchased from Evonik Industries, content 0.5 parts), bactericide (Protectol PE, purchased from Lanxess Chemical, content 0.2 parts), waterborne nano-polyurethane resin (TAKELAC W-5661, purchased from Mitsui Chemicals, content 8 parts), waterborne nano-pigment paste (CAB-O-JET 250C, purchased from Cabot Corporation, content 25.3 parts), and deionized water (20 parts).

[0050] The preparation method of the ink in this comparative example is the same as that in Example 1.

[0051] The ink application method for this comparative example includes: adding ink to a Kyocera HM-1800B-K24 printer with a QA printhead. Under ambient temperatures of 20-35°C and humidity of 55-75%, print a pure yellow patch using the same printing parameters as in Example 1. Print onto untreated woven fabric, and do not subject to post-printing light treatment.

[0052] Comparative Example 3: The ink in this comparative example is basically the same as that in Example 1, except that no photosensitive crosslinking agent is added and the amount of water-based nano-polyurethane resin is increased to 40 parts. Specifically, the ink in this comparative example... The raw materials for ink preparation include: polyol (neopentyl glycol, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., content 21 parts), humectant (erythritol, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., content 5 parts), surfactant (BYKJET-9131, purchased from BYK Chemical, content 1 part), defoamer (TEGO Foamex 825, purchased from Evonik Industries, content 0.5 parts), bactericide (Protectol PE, purchased from Lanxess Chemical, content 0.2 parts), waterborne nano-polyurethane resin (TAKELAC W-5661, purchased from Mitsui Chemicals, content 40 parts), waterborne nano-pigment paste (CAB-O-JET250C, purchased from Cabot Corporation, content 22.3 parts), and deionized water (content 10 parts).

[0053] The preparation method of the ink in this comparative example is the same as that in Example 1.

[0054] The ink application method for this comparative example includes: adding ink to a Kyocera HM-1800B-K24 printer with a QA printhead. Under ambient temperatures of 20-35°C and humidity of 55-75%, print a pure yellow patch using the same printing parameters as in Example 1. Print onto untreated woven fabric, and do not subject to post-printing light treatment.

[0055] Comparative Example 4: The ink in this comparative example is basically the same as that in Example 1, except that the amounts of polyol and deionized water were adjusted to change their ratio. Specifically, the raw materials for preparing the ink in this comparative example include: polyol (neopentyl glycol, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., content 40 parts), humectant (erythritol, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., content 5 parts), surfactant (BYKJET-9131, purchased from BYK Chemical, content 1 part), defoamer (TEGO Foamex 825, purchased from Evonik Industries, content 0.5 parts), bactericide (ProtectolPE, purchased from Lanxess Chemical, content 0.2 parts), waterborne nano-polyurethane resin (TAKELAC W-5661, purchased from Mitsui Chemicals, content 20 parts), waterborne nano-pigment paste (CAB-O-JET 250C, purchased from Cabot Corporation, content 23 parts), photocrosslinkable acrylate additive (content 1 part), and deionized water (content 9.3 parts).

[0056] The method for preparing the ink is the same as in Example 1.

[0057] The ink application method includes: adding ink to a Kyocera HM-1800B-K24 printer with a QA printhead. At an ambient temperature of 20-35°C and humidity of 55-75%, print a pure black patch using the same printing parameters as in Example 1. Print onto untreated woven fabric, and immediately after printing, irradiate under a 395 nm LED UV lamp (50 mW / cm²) for 120 seconds.

[0058] Comparative Example 5: The ink in this comparative example is basically the same as that in Example 1, except that the amounts of humectant and deionized water were adjusted to change their ratio. Specifically, the raw materials for preparing the ink in this comparative example include: polyol (neopentyl glycol, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., content 30 parts), humectant (erythritol, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., content 12 parts), surfactant (BYKJET-9131, purchased from BYK Chemical, content 1 part), defoamer (TEGO Foamex 825, purchased from Evonik Industries, content 0.5 parts), bactericide (Protectol PE, purchased from Lanxess Chemical, content 0.2 parts), waterborne nano-polyurethane resin (TAKELAC W-5661, purchased from Mitsui Chemicals, content 20 parts), waterborne nano-pigment paste (CAB-O-JET 250C, purchased from Cabot Corporation, content 23 parts), photocrosslinkable acrylate additive (content 1 part), and deionized water (content 12.3 parts).

[0059] The method for preparing the ink is the same as in Example 1.

[0060] The ink application method includes: adding ink to a Kyocera HM-1800B-K24 printer with a QA printhead. At an ambient temperature of 20-35°C and humidity of 55-75%, print a pure black patch using the same printing parameters as in Example 1. Print onto untreated woven fabric, and immediately after printing, irradiate under a 395 nm LED UV lamp (50 mW / cm²) for 120 seconds.

[0061] The performance of the inks of Examples 1-6 and Comparative Examples 1-3 were tested using the following test methods, and the test results are shown in Table 1.

[0062] Smoothness test: At 20-35℃ and 55-75% humidity, use the HM-1800B-K24 machine and Kyocera QA printhead to print 100 meters of pure yellow color blocks. Observe and record the number of broken needles. A number of broken needles ≤ 3 is considered qualified, otherwise it is unqualified.

[0063] Standby performance test: After printing, wait for 60 minutes at 20-35℃ and 55-70% humidity. Print a test strip without flash spray. If the test strip is complete, it is qualified. If it is blurry or has broken needles, it is unqualified.

[0064] Dry and wet rubbing fastness test: According to GB / T 3920-2008 "Textiles - Tests for color fastness to rubbing", the color fastness of the yellow color block is evaluated using a gray scale, with a full score of 5.

[0065] Water fastness test: According to GB / T 5713-2013 "Textiles - Tests for color fastness - Water fastness", the color difference and color change are evaluated using a gray scale, with a full score of 5 levels.

[0066] Table 1 Test results of the examples and comparative examples

[0067] As shown in Table 1, Examples 1-6 all exhibited excellent printability, standby performance, and color fastness, significantly superior to the comparative examples. The main reason for this is the unexpected discovery in this invention that, through the synergistic effect of photocrosslinkable acrylate additives and water-based nano-polyurethane resin, a dense crosslinked network is formed under post-printing light irradiation conditions, effectively improving the ink's color blocking performance and adhesion while maintaining good printability.

[0068] Comparative Example 1 did not add photocrosslinkable acrylate additives, nor did it undergo post-spray light treatment, resulting in the inability to form a crosslink network. Consequently, the color blocking effect and adhesion were significantly reduced, and the dry rubbing fastness, wet rubbing fastness, and wash fastness were all lower than those of the Example.

[0069] Comparative Example 2 did not add photocrosslinkable acrylate additives, and the amount of waterborne nano-polyurethane resin was reduced to 8 parts. The film-forming material was insufficient and there was no photosensitive crosslinking agent, which led to a further decrease in color blocking effect and adhesion. All color fastness indicators were the lowest.

[0070] Comparative Example 3 did not add a photocrosslinking agent, but the amount of water-based nano polyurethane resin was increased to 40 parts. Although the film-forming material was sufficient, the ink viscosity increased due to the excessive resin content. The number of interrupted needles in the flow test was as high as 8, and the standby performance was also unqualified. At the same time, due to the lack of a crosslinking network, the color fastness was still lower than that of the Example.

[0071] Although Comparative Example 4 added a photocrosslinkable acrylate additive, the amount of polyol was increased to 40 parts, and the amount of deionized water was reduced to 9.3 parts, resulting in a water-to-polyol ratio of 1:4.3. This solvent imbalance led to excessively low water content in the ink, causing it to dry too quickly. In the inkjet printing test, the ink flow was significantly reduced, with 6 needles broken, and the standby performance was unsatisfactory. Simultaneously, the excessively low water content affected the dispersion stability of the water-based nano-polyurethane resin and water-based nano-pigment paste. Although a crosslinked network was formed, poor substrate wettability resulted in decreased adhesion, with both dry and wet rubbing fastness lower than in the example.

[0072] Although Comparative Example 5 added a photocrosslinkable acrylate additive, the amount of humectant was increased to 12 parts, and the amount of deionized water was adjusted to 12.3 parts, resulting in a water-to-humectant ratio of only 1.025. Excessive use of humectant led to increased ink viscosity, resulting in 5 interrupted needles in the flow test, affecting printing stability. Furthermore, excessive humectant significantly reduced the ink drying speed. Even after a crosslinked network was formed, insufficient drying resulted in a sticky feel on the printed fabric, and a significant decrease in wash fastness, reaching only level 3, lower than the level 4-5 of the previous example.

[0073] In Example 3, the content of photocrosslinkable acrylate additive was low (0.2 parts), resulting in insufficient crosslinking reaction and slightly lower color fastness than other examples, but still better than the comparative example.

[0074] In Example 6, the content of waterborne nano-polyurethane resin was low (8 parts), but due to the addition of a photocrosslinking aid and light treatment, an effective crosslinking network could still be formed, and the color fastness was significantly higher than that of Comparative Example 2. This shows that the technical solution of the present invention can effectively reduce the amount of film-forming resin while maintaining a good color blocking effect.

[0075] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. 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 all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A pre-treatment free ink, characterized by, The ink comprises 0.2-2 parts by mass of a photosensitive crosslinking agent, 8-30 parts of a film-forming resin, and 15-25 parts of a colorant.

2. The pretreatment-free ink according to claim 1, characterized in that, The photosensitive crosslinking agent is a photo-crosslinkable acrylate additive.

3. The pre-treatment free ink according to claim 2, characterized in that, The photo-crosslinkable acrylate additive is a water-based polyacrylate containing a photoinitiator or a photosensitive resin.

4. The pre-treatment free ink of claim 1, wherein, The film-forming resin is a water-based nano polyurethane resin.

5. The pre-treatment free ink according to claim 4, characterized in that, The water-based nano polyurethane resin is selected from TAKELAC W-5661 or R130.

6. The pre-treatment free ink of claim 1, wherein, The colorant is a water-based nano pigment color paste.

7. The pre-treatment free ink according to claim 6, characterized in that, The water-based nano pigment color paste is selected from CAB-O-JET 250C or SP900BK.

8. The pre-treatment free ink of claim 1, wherein, It further comprises 25-40 parts of a polyol, 2-10 parts of a humectant, 0.1-5 parts of a surfactant, 0.1-5 parts of an antifoaming agent, 0.1-2 parts of a bactericide, and 10-20 parts of water.

9. Use of the pretreatment-free ink according to any one of claims 1 to 8, characterized in that, After the ink is inkjet printed on the surface of a textile fabric, it is irradiated under a UV lamp for 0.5-2 minutes to cause crosslinking reaction of the photosensitive crosslinking agent and the film-forming resin.

10. Use of the pre-treatment free ink according to claim 9, characterized in that, The wavelength of the UV lamp is 300-500 nm.

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