Coating direct-injection ink with stable printing fluency and bright color and preparation method of coating direct-injection ink

Abstract

The invention discloses coating direct-injection ink with stable printing fluency and bright color and a preparation method thereof. The coating direct-injection ink comprises the following raw material components in parts by weight: 10-40 parts of pigment color paste; 15 to 30 parts of water-based resin; 0.1 to 3 parts of double-end triethanolamine group polydimethylsiloxane; 5 to 40 parts of water; 10 to 35 parts of a humectant; and 0.1-3 parts of an auxiliary agent. According to the invention, the autonomously synthesized double-end triethanolamine polydimethylsiloxane is used as a surfactant, and triethanolamine groups are grafted at two ends of the polydimethylsiloxane, so that the surface tension of the ink can be stably reduced, the permeability of the ink on the surface of a fabric is improved, the ink and the fabric are combined more tightly, and the printing fastness is improved. Meanwhile, the double-end triethanolamine polydimethylsiloxane micelle structure can wrap pigment particles, so that the pigment particles are dispersed more uniformly, agglomeration is avoided, the storage stability of the ink is improved, and the color brightness is improved.

Description

Technical Field

[0001] This invention belongs to the field of textile ink technology, specifically relating to a direct-injection ink for coatings that provides smooth printing, stable color, and vibrant colors, and its preparation method. Background Technology

[0002] Direct-to-garment (DGG) digital printing is a textile digital inkjet printing technology that prints ink directly onto the front side of the fabric without the need for intermediate media. Ink droplets wet and penetrate the fiber surface, then adhere to the fabric structure at high temperatures. It boasts advantages such as a wide color gamut, high throughput, and fast delivery. Furthermore, the process is streamlined, eliminating the need for transfer media, hot melt powder, and heat presses compared to heat transfer printing. It also eliminates the need for subsequent steam washing, saving on material costs and significantly reducing wastewater generation and discharge, thus contributing to energy conservation and environmental protection. Therefore, DGG technology is highly favored in the textile digital printing field.

[0003] Direct-to-garment inks are designed according to waveform and pattern files, and the printhead voltage is controlled in real time to print on the fabric surface to obtain printed products. Ink quality is an important factor in determining the grade of inkjet printed textiles. High-quality inks should have the following characteristics: (1) strong wetting ability, which can spread fully on the fabric surface without leakage; (2) stable color development ability, which has strong color development ability on the fabric surface and will not produce obvious color changes due to high temperature; (3) aging stability, which will not delaminate or exceed the printhead's allowable printing range when stored under extreme conditions such as high and low temperature, humidity and bumps; (4) printing smoothness, which will not cause slant spraying, frame deviation, frame breakage and streaking under different temperature and humidity combinations for a long time; (5) the ability to give the fabric a better style coefficient, making it smoother and softer when worn, and the pattern has a more distinct sense of layering and brightness. The formulation system of pigment direct-to-garment inks requires the addition of high concentration of pigment paste and water-based resin, which places stricter requirements on the dispersion stability and moisturizing properties of the ink system. Inks with a high proportion of pigment are more prone to stratification and viscosity changes, leading to ink deterioration. Water-based resin inks, especially those used for high-width printing and long-duration printing, often experience accelerated resin cross-linking and film formation due to increased printhead surface temperature, resulting in poor printing quality. This forces production to be interrupted for adjustments, reducing production efficiency and extending product delivery time.

[0004] Therefore, there is an urgent need to develop a coating direct-to-garment ink that can improve printing smoothness, aging performance, and color vibrancy, thereby giving coating direct-to-garment ink products higher printing performance and wearability on fabrics. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a direct-to-garment ink with smooth printing, stable printing performance, and vibrant colors, and a method for preparing the same. The direct-to-garment ink features smooth printing and aging resistance; when printed on fabrics, it exhibits excellent fastness and hand feel, and also produces vibrant colors.

[0006] To solve the above-mentioned technical problems, the first aspect of the present invention provides a direct-injection ink for coatings, the raw material components of which, by weight, include:

[0007] 10-40 parts pigment paste; 15-30 parts of water-based resin; Surfactant 0.1-3 parts; 5-40 parts water; 10-35 parts of moisturizer; Additives: 0.1-3 parts; The surfactant is a bi-terminated triethanolamine polydimethylsiloxane.

[0008] Specifically, the direct-injection ink of this invention uses a self-synthesized bi-terminated triethanolamine polydimethylsiloxane as a surfactant. This surfactant, through the grafting of triethanolamine groups to both ends of the polydimethylsiloxane, forms an O / W structure with the orderly arrangement of the strongly hydrophilic bi-terminated triethanolamine groups and the hydrophobic intermediate siloxane molecule. This structure can stably reduce the surface tension of the ink, improve its penetration into the fabric surface, and make the ink and fabric bond more tightly, thereby improving the fastness of the print. Simultaneously, the bi-terminated triethanolamine polydimethylsiloxane micelle structure can encapsulate pigment particles, making their dispersion more uniform and preventing aggregation. This not only improves the ink's storage stability but also enhances color vibrancy.

[0009] Furthermore, the multi-branched structure of triethanolamine has a high critical micelle concentration, which helps reduce the interfacial tension between the solid and liquid phases, making the ink easier to wet on the fabric substrate surface. The Si-C and Si-O bonds in the main chain can rotate freely, and the molecules are highly flexible, which helps reduce the static friction coefficient of the inkjet pattern, giving the fabric a better feel and wearing comfort. The introduced amine groups allow the ink to combine with the hydroxyl groups in the fiber, improving adhesion. While cross-linking into a network, it can also react with water-based resins (such as polyurethane or acrylic resins) to synergistically enhance the density and strength of the coating, thus giving the inkjet pattern excellent abrasion resistance and water fastness. The hydroxyl groups at the two ends of triethanolamine can effectively lock in the water in the ink, preventing it from evaporating on the printhead surface and improving the wetting effect. This not only allows the ink to print continuously for a longer time without problems such as frame distortion and printhead clogging, but also ensures production efficiency and increases production capacity. At the same time, the polar groups of triethanolamine interact with the pigment, making the pigment dispersion more uniform and the colors printed on the fabric surface more vibrant; the multi-hydroxyl structure helps to enhance antioxidant properties and improve resistance to high-temperature yellowing, thus making the inkjet pattern more vibrant and resistant to yellowing.

[0010] In some embodiments of the present invention, the preparation process of the bi-terminated triethanolamine polydimethylsiloxane includes the following steps: (1) Under an inert atmosphere, dihydroxyl-terminated polydimethylsiloxane, triethanolamine and 4-dimethylaminopyridine were dissolved in toluene and cooled to obtain a mixed solution; (2) A toluene solution of N,N'-dicyclohexylcarbodiimide was added dropwise to the mixed solution, and the temperature was raised to carry out the reaction to obtain the bi-terminated triethanolamine polydimethylsiloxane.

[0011] In some embodiments of the present invention, the weight-average molecular weight of the dihydroxyl-terminated polydimethylsiloxane is 750-5000. For example, it can be 750, 1000, 2000, 3000 or 5000, etc., including but not limited to the listed values. At the same time, other unlisted values ​​within the numerical range are also applicable.

[0012] In some embodiments of the present invention, the molar ratio of the dihydroxyl-terminated polydimethylsiloxane, triethanolamine and N,N'-dicyclohexylcarbodiimide is 1:(0.5-1.5):(2-3); preferably, the molar ratio of the dihydroxyl-terminated polydimethylsiloxane, triethanolamine and N,N'-dicyclohexylcarbodiimide is 1:(0.8-1.2):(2-2.5).

[0013] In some embodiments of the present invention, the molar ratio of 4-dimethylaminopyridine to toluene is (1-10):100; preferably, the molar ratio of 4-dimethylaminopyridine to toluene is (1-5):100. The toluene is the sum of the amount of toluene used in step (1) and the amount of toluene used in the toluene solution of N,N'-dicyclohexylcarbodiimide in step (2).

[0014] In some embodiments of the present invention, the concentration of the toluene solution of N,N'-dicyclohexylcarbodiimide is 30-40 wt%; preferably, the concentration of the toluene solution of N,N'-dicyclohexylcarbodiimide is 30-35 wt%.

[0015] In some embodiments of the present invention, the molar concentration of the bi-hydroxyl-terminated polydimethylsiloxane in the mixed solution is 0.01-1.2 mol / L; preferably, the molar concentration of the bi-hydroxyl-terminated polydimethylsiloxane is 0.02-1 mol / L.

[0016] In some embodiments of the present invention, in step (1), the cooling is performed to 0-5°C.

[0017] In some embodiments of the present invention, in step (2), the temperature is raised to 25-30°C.

[0018] In some embodiments of the present invention, the aqueous resin is selected from aqueous polyurethane resins and / or aqueous acrylic resins. For example, TAKELAC from Mitsui Chemicals, Japan, can be used. TM W-6061, Japan Mitsui Chemicals TAKELAC TM W-6110, BASF JONCRYL 8055, Covestro Impranil DL 1606 or Covestro Impranil DL 1116.

[0019] In some embodiments of the present invention, the humectant is selected from at least one of ethylene glycol, diethylene glycol, propylene glycol, glycerin, diethylene glycol monobutyl ether, and 1,6-hexanediol.

[0020] In some embodiments of the present invention, the additives include at least one of defoamers, bactericides, and curing agents.

[0021] In some embodiments of the present invention, the defoamer may be a commonly used defoamer in the art, such as BYK-052 or BYK-348 from BYK Chemicals (Germany) or SURFYNOL from Evonik (Germany). ® DF-110D.

[0022] In some embodiments of the present invention, the amount of the defoamer is 0.1-0.5 parts by weight.

[0023] In some embodiments of the present invention, the bactericide may be a commonly used bactericide in the art, for example, KATHON LXE from Dow Chemical Company.

[0024] In some embodiments of the present invention, the amount of the bactericide used is 0.05-0.5 parts by weight.

[0025] In some embodiments of the present invention, the curing agent includes a blocked isocyanate, for example, Covestro XL6366 blocked isocyanate from Germany.

[0026] In some embodiments of the present invention, the amount of the curing agent is 0.25-2 parts by weight.

[0027] In some embodiments of the present invention, the water is deionized water.

[0028] In some embodiments of the present invention, the pigment paste may be a commonly used pigment paste in the art, such as cyan D71C / 15:3, D75C / 15:3, magenta D71M / pb122, D71R / 57:1 and D75M / pb122, yellow D71Y / 74y, D75Y / 74y, black D75K / pb7, Cabot Corporation black CAB-O-JET 200K, Hangzhou Transfar XunCai black TF-PK107, cyan TF-PC103, magenta TF-PM102, TF-PM109 or yellow TF-PY105.

[0029] A second aspect of the present invention provides a method for preparing the above-mentioned direct-injection ink for coatings, comprising the following steps: The raw materials are mixed and filtered to obtain the direct-injection ink for the coating.

[0030] In some embodiments of the present invention, the mixing refers to stirring at a speed of 400-600 rpm for 40-80 minutes.

[0031] A third aspect of the present invention provides a fabric, wherein the raw materials for preparing the fabric include the above-mentioned direct-injection ink for coatings.

[0032] Compared with the prior art, the above-described technical solution of the present invention has at least the following technical effects or advantages: (1) The direct-injection ink of the present invention uses a self-synthesized bi-terminated triethanolamine polydimethylsiloxane as a surfactant. This surfactant, by grafting triethanolamine groups onto both ends of the polydimethylsiloxane, can not only stably reduce the surface tension of the ink and improve the ink's surface penetration and wettability on fabrics, but also ensure stable storage and prevent agglomeration. The hydroxyl groups of the bi-terminated triethanolamine groups can effectively lock in the moisture in the ink, making the ink printing smooth and stable.

[0033] (2) The amine groups introduced in the surfactant combine with the hydroxyl groups in the ink and fiber to improve adhesion. While cross-linking into a network, it also reacts with the water-based resin to synergistically enhance the density and strength of the coating, thereby improving the fabric’s abrasion resistance and water fastness.

[0034] (3) The Si-C and Si-O bonds in the surfactant can rotate freely, resulting in high molecular flexibility and giving the fabric a comfortable feel. The polar groups of triethanolamine can interact with the pigment, making it more evenly dispersed and more vibrant when printed on the fabric surface; the polyhydroxy structure enhances the antioxidant properties of the fabric, giving it good resistance to high-temperature yellowing. Detailed Implementation

[0035] The present invention will now be described in detail with reference to embodiments to facilitate understanding of the invention by those skilled in the art. It is particularly important to note that the embodiments are merely illustrative of the invention and should not be construed as limiting the scope of protection of the invention. Non-essential improvements and adjustments made to the invention by those skilled in the art based on the above description should still fall within the scope of protection of the invention. Furthermore, all raw materials mentioned below, unless otherwise specified, are commercially available products; all process steps or preparation methods not mentioned in detail are process steps or preparation methods known to those skilled in the art.

[0036] Example 1 A direct-injection ink for coatings, comprising the following raw material components by weight: 30 parts of pigment paste, Cabot CAB-O-JET 200K black pigment paste from the USA; 25 parts of water-based resin, manufactured by Mitsui Chemicals (TAKELAC) of Japan. TM W-6061; Surfactant A1, 0.5 parts, is a bi-terminated triethanolamine polydimethylsiloxane; 20 parts of humectant, including: 5 parts of 1,6-hexanediol, 5 parts of propylene glycol, and 10 parts of diethylene glycol; 1.4 parts of additives, including: 1 part of curing agent Covestro XL6366 blocked isocyanate from Germany, 0.1 part of defoamer BYK-348 from Germany, and 0.3 parts of bactericide KATHON LXE from Dow Chemical from the United States; Water 23.1 parts.

[0037] The preparation process of surfactant A1 includes the following steps: (1) In a container protected by nitrogen atmosphere, add 56 parts by weight of dihydroxyl-terminated polydimethylsiloxane (weight average molecular weight of 1000), 8.4 parts by weight of triethanolamine and 1.4 parts by weight of 4-dimethylaminopyridine to 45 parts by weight of toluene, stir and disperse, and cool to 5°C to obtain a mixed solution.

[0038] (2) In a container at a temperature of 5°C, 25.4 parts of N,N'-dicyclohexylcarbodiimide were dissolved in 50.8 parts of toluene to prepare a toluene solution of N,N'-dicyclohexylcarbodiimide; (3) In an environment with a temperature below 10°C, the toluene solution of N,N'-dicyclohexylcarbodiimide obtained in step (2) is slowly added dropwise to the mixed solution obtained in step (1). After the addition is complete, the temperature is raised to 25°C and stirred evenly. The solution is washed and filtered with cold toluene to obtain a double-terminated triethanolamine polydimethylsiloxane, i.e. surfactant A1.

[0039] A method for preparing a direct-injection ink for coatings includes the following steps: Weigh each raw material according to the raw material ratio, stir at 500 rpm for 60 minutes, filter, and obtain the black ink of this embodiment.

[0040] Example 2 A direct-injection ink for coatings, comprising the following raw material components by weight: 25 parts of pigment paste, Lubrizol D71M / pb122 magenta paste; 25 parts of water-based resin, manufactured by Mitsui Chemicals (TAKELAC) of Japan. TM W-6110; Surfactant A2, 0.5 parts, is a bi-terminated triethanolamine polydimethylsiloxane; 25 parts of moisturizer, including: 5 parts of diethylene glycol monobutyl ether, 10 parts of ethylene glycol, and 10 parts of diethylene glycol; 1.4 parts of additives, including: 1 part of curing agent Covestro XL6366 blocked isocyanate from Germany, 0.1 part of defoamer BYK-348 from Germany, and 0.3 parts of bactericide KATHON LXE from Dow Chemical from the United States; Water 23.1 parts.

[0041] The preparation process of surfactant A2 includes the following steps: (1) In a container protected by nitrogen atmosphere, add 72 parts by weight of dihydroxyl-terminated polydimethylsiloxane (weight average molecular weight of 3000), 4 parts by weight of triethanolamine, and 0.15 parts by weight of 4-dimethylaminopyridine to 456.2 parts by weight of toluene, stir and disperse, and cool to 5°C to obtain a mixed solution.

[0042] (2) In a container at a temperature of 5°C, 11.9 parts of N,N'-dicyclohexylcarbodiimide were dissolved in 23.8 parts of toluene to prepare a toluene solution of N,N'-dicyclohexylcarbodiimide; (3) In an environment with a temperature below 10°C, the toluene solution of N,N'-dicyclohexylcarbodiimide obtained in step (2) is slowly added dropwise to the mixed solution obtained in step (1). After the addition is complete, the temperature is raised to 25°C and stirred evenly. The solution is washed and filtered with cold toluene to obtain a double-terminated triethanolamine polydimethylsiloxane, i.e., surfactant A2.

[0043] A method for preparing a direct-injection ink for coatings includes the following steps: Weigh each ingredient according to the specified ratio, stir at 500 rpm for 60 minutes, filter, and obtain the magenta ink of this embodiment.

[0044] Example 3 A direct-injection ink for coatings, comprising the following raw material components by weight: 20 parts of pigment paste, which is Hangzhou Chuanhua Xuncai TF-PC103 cyan pigment paste; 25 parts of water-based resin, namely BASF JONCRYL 8055 from Germany; Surfactant A3, 0.3 parts, is a bi-terminated triethanolamine polydimethylsiloxane; 35 parts of moisturizer, including: 5 parts of ethylene glycol, 10 parts of diethylene glycol, and 20 parts of diethylene glycol monobutyl ether; 1.4 parts of additives, including: 1 part of curing agent Covestro XL6366 blocked isocyanate from Germany, 0.1 part of defoamer BYK-348 from Germany, and 0.3 parts of bactericide KATHON LXE from Dow Chemical from the United States; 18.3 parts water.

[0045] The preparation process of surfactant A3 includes the following steps: (1) In a container protected by nitrogen atmosphere, 72 parts by weight of dihydroxyl-terminated polydimethylsiloxane (weight average molecular weight of 5000), 4.2 parts by weight of triethanolamine and 0.02 parts by weight of 4-dimethylaminopyridine were added to 243.2 parts by weight of toluene, stirred and dispersed, and the temperature was lowered to 5°C to cool and obtain a mixed solution.

[0046] (2) In a container at a temperature of 5°C, 6.4 parts of N,N'-dicyclohexylcarbodiimide were dissolved in 12.8 parts of toluene to prepare a toluene solution of N,N'-dicyclohexylcarbodiimide; (3) In an environment with a temperature below 10°C, the toluene solution of N,N'-dicyclohexylcarbodiimide obtained in step (2) is slowly added dropwise to the mixed solution obtained in step (1). After the addition is complete, the temperature is raised to 25°C and stirred evenly. The solution is washed and filtered with cold toluene to obtain a double-terminated triethanolamine polydimethylsiloxane, i.e. surfactant A3.

[0047] A method for preparing a direct-injection ink for coatings includes the following steps: Weigh each ingredient according to the specified ratio, stir at 500 rpm for 60 minutes, filter, and obtain the cyan ink of this embodiment.

[0048] Example 4 A direct-injection ink for coatings, comprising the following raw material components by weight: 25 parts of pigment paste, which is Hangzhou Chuanhua Xuncai TF-PM109 magenta paste; 25 parts of water-based resin, namely Covestro Impranil DL 1606 from Germany; 0.5 parts of surfactant, including: 0.2 parts of surfactant A1, 0.2 parts of surfactant A2, and 0.1 parts of surfactant A3; 25 parts of humectant, including: 10 parts of ethylene glycol, 10 parts of diethylene glycol monobutyl ether, and 5 parts of glycerol; 1.1 parts of additives, including: 1 part of curing agent (Covestro XL6366 blocked isocyanate from Germany) and 1 part of defoamer (Evonik SURFYNOL from Germany). ® DF-110D 0.1 parts, bactericide is Dow Chemical KATHON LXE 0.3 parts; 23.4 parts water.

[0049] The preparation processes of surfactants A1, A2, and A3 are the same as those in Examples 1, 2, and 3, respectively.

[0050] A method for preparing a direct-injection ink for coatings includes the following steps: Weigh each ingredient according to the specified ratio, stir at 500 rpm for 60 minutes, filter, and obtain the magenta ink of this embodiment.

[0051] Example 5 A direct-injection ink for coatings, comprising the following raw material components by weight: 25 parts of pigment paste, Lubrizol D71C / 15:3 cyan pigment paste; 25 parts of water-based resin, namely Covestro Impranil DL 1116 from Germany; 0.55 parts of surfactant, of which: surfactant A1 0.2 parts and surfactant A2 0.35 parts; 28 parts of humectant, including: 10 parts of propylene glycol, 10 parts of diethylene glycol, and 8 parts of glycerol; 1.4 parts of additives, including: 1 part of curing agent Covestro XL6366 blocked isocyanate from Germany, 0.1 part of defoamer BYK-052 from Germany, and 0.3 parts of bactericide KATHON LXE from Dow Chemical from the United States; Water 20.05 parts.

[0052] The preparation processes of surfactants A1 and A2 are the same as those in Examples 1 and 2, respectively.

[0053] A method for preparing a direct-injection ink for coatings includes the following steps: Weigh each ingredient according to the specified ratio, stir at 500 rpm for 60 minutes, filter, and obtain the cyan ink of this embodiment.

[0054] Example 6 A direct-injection ink for coatings, comprising the following raw material components by weight: 34 parts of pigment paste, which is Lubrizol D71Y / 74y yellow pigment paste from the UK company Lubrizol; 30 parts of water-based resin, namely Covestro Impranil DL 1606 from Germany; One part of surfactant, comprising: 0.4 parts of surfactant A1 and 0.6 parts of surfactant A3; 20 parts of moisturizer, including: 10 parts of propylene glycol, 5 parts of diethylene glycol, and 5 parts of glycerol; 1.4 parts of additives, including: 1 part of curing agent Covestro XL6366 blocked isocyanate from Germany, 0.1 part of defoamer BYK-052 from Germany, and 0.3 parts of bactericide KATHON LXE from Dow Chemical from the United States; Water 13.6 parts.

[0055] The preparation processes of surfactants A1 and A3 are the same as those in Examples 1 and 3, respectively.

[0056] A method for preparing a direct-injection ink for coatings includes the following steps: Weigh each ingredient according to the specified ratio, stir at 500 rpm for 60 minutes, filter, and obtain the yellow ink of this embodiment.

[0057] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that surfactant A1 was replaced with an equal amount of Evonik SURFYNOL. ® 465 surfactant.

[0058] Comparative Example 2 The difference between Comparative Example 2 and Example 2 is that surfactant A2 was replaced with an equal amount of Evonik SURFYNOL. ® 485 surfactant.

[0059] Comparative Example 3 The difference between Comparative Example 3 and Example 3 is that surfactant A3 was replaced with an equal amount of NP-10 surfactant from Guangzhou Zhanlin Chemical Co., Ltd.

[0060] Comparative Example 4 The only difference between Comparative Example 4 and Example 4 is that the surfactants (surfactant A1 0.2 parts, surfactant A2 0.2 parts, surfactant A3 0.1 parts) in the raw material components of the direct-injection ink of Example 4 were replaced with 3 parts of AEO-9 surfactant from Shandong Yousuo Chemical Co., Ltd. and 3 parts of APG surfactant from Guangdong Gongying Chemical Co., Ltd., and the deionized water was reduced to 17.6 parts accordingly.

[0061] Comparative Example 5 The only difference between Comparative Example 5 and Example 5 is that the surfactants (surfactant A1 0.2 parts, surfactant A2 0.35 parts) in the raw material components of the direct-injection ink of Example 5 were replaced with SURFYNOL from Evonik. ® 0.2 parts of 465 surfactant and 0.5 parts of IOTA 2110 siloxane from Anhui Aiyota Company were added, while the amount of deionized water was reduced to 19.9 parts accordingly.

[0062] Comparative Example 6 The only difference between Comparative Example 6 and Example 6 is that the surfactants (surfactant A1 0.4 parts, surfactant A3 0.6 parts) in the raw material components of the direct-injection ink of Example 6 were replaced with SURFYNOL from Evonik. ® 0.5 parts of 485 surfactant and 0.5 parts of IOTA 2110 siloxane from Anhui Aiyota Company.

[0063] Comparative Example 7 The difference between Comparative Example 7 and Example 1 is that 0.5 parts of surfactant A1 in the raw material components of the direct-injection ink of Example 1 were replaced with SURFYNOL from Evonik. ® 0.5 parts of 465 surfactant and 0.5 parts of Dow's hydroxyl silicone oil PMX-0156 were added, while the amount of deionized water was reduced to 22.6 parts accordingly.

[0064] Comparative Example 8 The difference between Comparative Example 8 and Example 1 is that 0.5 parts of surfactant A1 in the raw material components of the direct-injection ink of Example 1 were replaced with SURFYNOL from Evonik. ® 0.5 parts of 465 surfactant and 0.5 parts of Dow's amino silicone oil OFX-8040A were added, while the amount of deionized water was reduced to 22.6 parts accordingly.

[0065] Comparative Example 9 The only difference between Comparative Example 9 and Example 4 is that the surfactants (surfactant A1 0.2 parts, surfactant A2 0.2 parts, surfactant A3 0.1 parts) in the raw material components of the direct-injection ink of Example 4 are replaced with surfactant B1 0.2 parts, surfactant B2 0.2 parts, and surfactant B3 0.1 parts.

[0066] The preparation process of surfactant B1 includes the following steps: (1) In a container under nitrogen atmosphere protection, 56 parts by weight of dihydroxyl-terminated polydimethylsiloxane (weight average molecular weight of 1000) and 7 parts by weight of hexamethyldisilazane were dissolved in 60 parts by weight of anhydrous ethanol and 120 parts by weight of deionized water. The mixture was stirred at 200 rpm and heated to 80°C for 3 hours to allow the dihydroxyl-terminated polydimethylsiloxane and hexamethyldisilazane to react fully. The mixture was cooled to 25°C, and 15 parts by weight of activated carbon were added to adsorb unreacted hexamethyldisilazane. The mixture was stirred for 30 minutes and filtered to obtain an ethanol solution of dihydroxyl-terminated silicone oil. The solution was poured into a separatory funnel, 50 parts by weight of deionized water were added, and the mixture was shaken and allowed to stand for separation. The upper aqueous phase was discarded. The washing was repeated 2-3 times until the aqueous phase was neutral. The lower product was poured into a beaker, 20 parts by weight of anhydrous sodium sulfate were added, and the mixture was stirred for 1 hour and filtered to obtain dried dihydroxyl-terminated polydimethylsiloxane (H-PDMS).

[0067] (2) Add 56 parts H-PDMS, 20 parts polyether (PE) and 0.015 parts chloroplatinic acid to a reaction vessel, heat to 100°C and stir at 200 rpm for 1 hour; raise the temperature to 130°C and continue for 5 hours to allow the Si-H bonds to react completely with the polyether, cool to 25°C, add 60 parts anhydrous ethanol and stir for 30 min, let stand to separate the layers, pour the upper product into a vacuum distillation apparatus at 90°C and -0.09 MPa for 3 hours to remove residual ethanol and unreacted polyether; put the distilled product into a vacuum drying oven and dry at 80°C for 2 hours to obtain the alcohol-terminated hydroxyl polyether modified siloxane polymer, i.e. surfactant B1.

[0068] The preparation process of surfactant B2 includes the following steps: (1) In a container under nitrogen atmosphere protection, add 98 parts by weight of dihydroxyl-terminated polydimethylsiloxane (weight average molecular weight of 3000) and 12.25 parts by weight of hexamethyldisilazane, dissolve them in 105 parts by weight of anhydrous ethanol and 210 parts by weight of deionized water, stir at 200 rpm, heat to 80°C and continue the reaction for 3 hours to ensure that the dihydroxyl-terminated polydimethylsiloxane and hexamethyldisilazane react completely, cool to 25°C, add 26 parts by weight of activated carbon to adsorb unreacted hexamethyldisilazane, stir for 30 min, filter to obtain an ethanol solution of dihydroxyl-terminated silicone oil. Pour the solution into a separatory funnel, add 210 parts by weight of deionized water, shake and let stand to separate the layers, discard the upper aqueous phase. Repeat washing 2-3 times until the aqueous phase is neutral. The lower layer product was poured into a beaker, 35 parts of anhydrous sodium sulfate were added, the mixture was stirred for 1 hour, filtered, and dried hydroxyl-terminated polydimethylsiloxane (H-PDMS) was obtained.

[0069] (2) Add 98 parts H-PDMS, 35 parts polyether (PE) and 0.0263 parts chloroplatinic acid to a reaction vessel, heat to 100°C and stir at 200 rpm for 1 hour; raise the temperature to 130°C and continue for 5 hours to allow the Si-H bonds to react completely with the polyether, cool to 25°C, add 105 parts anhydrous ethanol and stir for 30 min, let stand to separate the layers, pour the upper product into a vacuum distillation apparatus at 90°C and -0.09 MPa for 3 hours to remove residual ethanol and unreacted polyether; put the distilled product into a vacuum drying oven and dry at 80°C for 2 hours to obtain the alcohol-terminated hydroxyl polyether modified siloxane polymer, i.e. surfactant B2.

[0070] The preparation process of surfactant B3 includes the following steps: (1) In a container under nitrogen atmosphere protection, add 98 parts by weight of dihydroxyl-terminated polydimethylsiloxane (weight average molecular weight of 5000) and 13.95 parts by weight of hexamethyldisilazane, dissolve them in 105 parts by weight of anhydrous ethanol and 210 parts by weight of deionized water, stir at 200 rpm, heat to 80°C and continue the reaction for 3 hours to ensure that the dihydroxyl-terminated polydimethylsiloxane and hexamethyldisilazane react completely, cool to 25°C, add 26 parts by weight of activated carbon to adsorb unreacted hexamethyldisilazane, stir for 30 min, filter to obtain an ethanol solution of dihydroxyl-terminated silicone oil. Pour the solution into a separatory funnel, add 210 parts by weight of deionized water, shake and let stand to separate the layers, discard the upper aqueous phase. Repeat washing 2-3 times until the aqueous phase is neutral. The lower layer product was poured into a beaker, 35 parts of anhydrous sodium sulfate were added, the mixture was stirred for 1 hour, filtered, and dried hydroxyl-terminated polydimethylsiloxane (H-PDMS) was obtained.

[0071] (2) Add 98 parts H-PDMS, 35 parts polyether (PE) and 0.0263 parts chloroplatinic acid to a reaction vessel, heat to 100°C and stir at 200 rpm for 1 hour; raise the temperature to 130°C and continue for 5 hours to allow the Si-H bonds to react completely with the polyether, cool to 25°C, add 105 parts anhydrous ethanol and stir for 30 min, let stand to separate the layers, pour the upper product into a vacuum distillation apparatus at 90°C and -0.09 MPa for 3 hours to remove residual ethanol and unreacted polyether; put the distilled product into a vacuum drying oven and dry at 80°C for 2 hours to obtain the alcohol-terminated hydroxyl polyether modified siloxane polymer, i.e. surfactant B3.

[0072] Comparative Example 10 The only difference between Comparative Example 10 and Example 5 is that the surfactants (surfactant A1 0.2 parts, surfactant A2 0.35 parts) in the raw material components of the direct-injection ink of Example 5 are replaced with surfactant B1 0.2 parts and surfactant B2 0.35 parts.

[0073] The preparation processes of surfactants B1 and B2 are the same as those of Comparative Example 9.

[0074] Comparative Example 11 The only difference between Comparative Example 11 and Example 6 is that the surfactants (surfactant A1 0.4 parts, surfactant A3 0.6 parts) in the raw material components of the direct-injection ink of Example 6 are replaced with surfactant B1 0.4 parts and surfactant B3 0.6 parts.

[0075] The preparation processes for surfactants B1 and B3 were the same as those for Comparative Example 9.

[0076] Performance testing 1. Ink performance parameters and aging resistance The surface tension and viscosity at room temperature of the paint direct injection inks prepared in Examples 1-6 and Comparative Examples 1-11 were tested, and the stratification after standing at room temperature for 7 days and 14 days was recorded. The results are shown in Table 1.

[0077] Table 1:

[0078] 2. Printing smoothness The paint direct-injection inks prepared in Examples 1-6 and Comparative Examples 1-11 were printed using a Kyocera EX600 printhead. After printing solid color blocks with a width of 1 meter and a length of 300 meters using a 2-pass continuous printing method on the printer, the number of test strips and the number of broken holes were increased. The results are shown in Table 2.

[0079] Table 2:

[0080] 3. Color development performance In color science, color vibrancy is usually expressed as chroma. 'a' represents the red-green axis and 'b' represents the yellow-blue axis. A higher chroma C value indicates a more vibrant ink color. For black, only the L value is compared for depth; a lower L value indicates a deeper black. The paint direct-injection inks prepared in Examples 1-6 and Comparative Examples 1-11 were printed on cotton knitted fabrics to test chroma and depth. The test results are shown in Table 3.

[0081] Table 3:

[0082] 4. Durability and feel test The paint direct-injection inks prepared in Examples 1-6 and Comparative Examples 1-11 were printed on the front side of cotton knitted fabrics, and the fastness and hand feel were tested.

[0083] The dry and wet rubbing fastness test methods and grades are evaluated in accordance with standard GB / T 3920-2008.

[0084] The test method for water immersion dry rubbing fastness is as follows: After soaking the printed cloth strip in water for 1 hour, squeeze out the excess water and fix it on the sample stage of the test instrument. Fix the dry rubbing white cloth on the upper weight rubbing head, and then perform 10 rubbing cycles on the printed rubbing strip and observe the staining of the white cloth.

[0085] The wash fastness test method and evaluation were conducted according to standard GB / T 3921-2008. The test procedure was as follows: A 40mm × 100mm printed cotton strip was taken, and the colored side was sewn along the edge to a 40mm × 100mm cotton strip with the same staining ability to form a sample. The sample was placed in soapy water heated continuously at 60℃ and washed at 500rpm for 30 minutes, repeated 5 times. After washing, the sample was dried in an oven at 60℃, and the staining grade of the lining was tested using a staining grey scale.

[0086] Hand feel test: Fold the colored printed fabric strip in half and rub it with your fingers to evaluate its feel. No noticeable resistance is considered smooth, while resistance is considered rough.

[0087] The test results described above are shown in Table 4.

[0088] Table 4

[0089] Based on the test results in Table 1-4 above, the following conclusions can be drawn: (1) Compared with the paint direct-injection inks prepared in Examples 1-6 and Comparative Examples 2-5 and 9-11, no stratification phenomenon was observed after 14 days of high-temperature storage, and the changes in viscosity and tension were all less than 0.15. This indicates that the dual-terminated triethanolamine polydimethylsiloxane polymer surfactant prepared in this invention has excellent compatibility in inks, giving the inks excellent storage performance stability.

[0090] (2) Compared with the direct-injection inks prepared in Examples 1-6 and Comparative Examples 1-11, the number of newly added broken holes in Examples 1-6 after continuous printing for 300 meters was much smaller than that in Comparative Examples 1-11. This shows that the dual-terminated triethanolamine polydimethylsiloxane polymer surfactant prepared in this invention gives the ink better moisturizing properties, stable printing smoothness, and can ensure continuous and efficient production.

[0091] (3) The wet rubbing fastness tests of the direct-injection inks prepared in Examples 1-6 all reached grade 3-4 or above, which is superior to Comparative Example 9 and Comparative Example 11, which had the highest wet rubbing fastness grades among Comparative Examples 1-11. Furthermore, the inks in Examples 3, 4, and 6, which contain a large molecular weight bipolar triethanolamine-based polydimethylsiloxane polymer A3 surfactant, achieved a wet rubbing fastness grade of grade 4 or above. In Example 6, increasing the total proportion of bipolar triethanolamine-based polydimethylsiloxane polymer surfactant to 1% significantly improved the wet rubbing fastness to grade 4-5. This indicates that the bipolar triethanolamine-based polydimethylsiloxane polymer surfactant prepared in this invention not only crosslinks the terminal amino groups to form a network but also reacts with the resin to synergistically enhance the density and strength of the coating. Moreover, the fastness is correspondingly enhanced as the molecular weight and proportion of the surfactant increase.

[0092] (4) The paint direct-injection inks prepared in Comparative Examples 6-8, although the addition of domestic and imported silicone oils can make the inks have a smooth feel, the grades of abrasion resistance, water washing and water immersion fastness are all lower than those in Examples 1-6. This indicates that the double-terminated triethanolamine polydimethylsiloxane polymer surfactant prepared in this invention not only retains the smooth feel of traditional silicone oils, but also gives the coating excellent abrasion resistance and water resistance.

[0093] (5) Compared with the black ink prepared in Comparative Examples 1, 7, and 8, Example 1 has a smaller L value and a deeper color; compared with the magenta ink prepared in Comparative Example 2, Example 2 has a larger C value; compared with the cyan ink prepared in Comparative Example 3, Example 3 has a larger C value; compared with the yellow ink prepared in Comparative Examples 6 and 11, Example 6 has a larger C value. This indicates that the bi-terminated triethanolamine polydimethylsiloxane polymer surfactant prepared in this invention can enhance the color development ability of inks and increase their brightness.

[0094] (6) The inks prepared by adding domestic silicone oil in Comparative Examples 5 and 6, adding imported silicone oil in Comparative Examples 7 and 8, and adding silicone oil synthesized by other methods in Comparative Examples 9-11 all had a smooth feel, but compared with the ink prepared in Example 4 (with 0 new holes), the number of broken holes increased by 40-60 compared with the ink with a smoothness of 300 meters. This shows that the dual-terminated triethanolamine polydimethylsiloxane polymer surfactant prepared by this invention has better printing stability than domestic, imported, and other silicone oils synthesized by other methods, which can ensure continuous mass printing without drying out the printing head.

[0095] For those skilled in the art, several simple deductions or substitutions can be made without departing from the inventive concept, without requiring creative effort. Therefore, any simple improvements made to this invention by those skilled in the art based on the disclosure of this invention should be within the scope of protection of this invention. The above embodiments are preferred embodiments of this invention, and all processes similar to this invention and equivalent changes should fall within the scope of protection of this invention.

Claims

1. A direct-injection ink for coatings, characterized in that, Its raw material components, by weight, include: 10-40 parts pigment paste; 15-30 parts of water-based resin; Surfactant 0.1-3 parts; 5-40 parts water; 10-35 parts of moisturizer; Additives: 0.1-3 parts; The surfactant is a bi-terminated triethanolamine polydimethylsiloxane.

2. The direct-injection ink for coatings according to claim 1, characterized in that, The preparation process of the bi-terminated triethanolamine polydimethylsiloxane includes the following steps: (1) Under an inert atmosphere, dihydroxyl-terminated polydimethylsiloxane, triethanolamine and 4-dimethylaminopyridine were dissolved in toluene and cooled to obtain a mixed solution; (2) A toluene solution of N,N'-dicyclohexylcarbodiimide was added dropwise to the mixed solution, and the temperature was raised to carry out the reaction to obtain the bi-terminated triethanolamine polydimethylsiloxane.

3. The direct-injection ink for coatings according to claim 2, characterized in that, The weight-average molecular weight of the bi-hydroxyl-terminated polydimethylsiloxane is 750-5000.

4. The direct-injection ink for coatings according to claim 2, characterized in that, The molar ratio of the dihydroxyl-terminated polydimethylsiloxane, triethanolamine, and N,N'-dicyclohexylcarbodiimide is 1:(0.5-1.5):(2-3). And / or, the molar ratio of 4-dimethylaminopyridine to toluene is (1-10):100; And / or, the concentration of the toluene solution of the N,N'-dicyclohexylcarbodiimide is 30-40 wt%; And / or, in the mixed solution, the molar concentration of the dihydroxyl-terminated polydimethylsiloxane is 0.01-1.2 mol / L.

5. The direct-injection ink for coatings according to claim 2, characterized in that, In step (1), the cooling is carried out to 0-5°C; and / or, in step (2), the heating is carried out to 25-30°C.

6. The direct-injection ink for coatings according to claim 1, characterized in that, The waterborne resin is selected from waterborne polyurethane resin and / or waterborne acrylic resin.

7. The direct-injection ink for coatings according to claim 1, characterized in that, The moisturizer is selected from at least one of ethylene glycol, diethylene glycol, propylene glycol, glycerin, diethylene glycol monobutyl ether, and 1,6-hexanediol; And / or, the additives include at least one of defoamers, bactericides and curing agents.

8. The direct-injection ink for coatings according to claim 7, characterized in that, The curing agent includes a blocked isocyanate.

9. A method for preparing a direct-injection ink for coatings as described in any one of claims 1-8, characterized in that, Includes the following steps: The raw materials are mixed and filtered to obtain the direct-injection ink for the coating.

10. A fabric, characterized in that, The raw materials for preparing the fabric include the direct-injection ink for coatings as described in any one of claims 1-8.

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