Coating ink printing scheme

Abstract

Provided is a coating ink printing scheme, relating to the technical field of digital printing. The provided coating ink printing scheme comprises: loading a first ink and a second ink into a multi-nozzle inkjet printer, and sequentially spraying the first ink and the second ink onto a transfer printing medium during operation of the printer. The first ink comprises an aqueous nano-polyurethane emulsion. The second ink is a transparent ink, and the transparent ink comprises an aqueous hot-melt nano-polyurethane emulsion. The aqueous hot-melt nano-polyurethane emulsion accounts for 60-70% of the total mass of the transparent ink. The elongation percentage of aqueous nano-polyurethane in the aqueous nano-polyurethane emulsion is 180-600%. The elongation percentage of the aqueous hot-melt nano-polyurethane is 1,500-1,800%. In the printing scheme, rapid printing can be achieved, a pattern transferred onto a fabric is complete, the operation is simple, and the fabric is tightly attached to the printed color pattern. When the fabric is rubbed, the pattern does not deform or fall off, and is likewise not prone to fading.

Description

A coating ink printing solution

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 2024115120137, filed on October 28, 2024, entitled "A Coating Ink Printing Scheme", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application belongs to the field of digital printing technology, specifically relating to a coating ink printing solution. Background Technology

[0004] In traditional digital textile heat transfer printing, the powder-shaking process is a commonly used technique. It primarily relies on powder-shaking machines, such as the Orica OR-6202DTF, Taituo Digital 60E3-K, and Sasguang white ink heat transfer powder-shaking machines, to evenly distribute hot melt adhesive powder onto a pre-printed heat transfer film. Excess powder is then shaken off, and finally, baking melts the hot melt powder onto the heat transfer film, enhancing the adhesion and durability between the design and the textile. This ensures the design does not deform or peel off and is less prone to fading when the fabric is rubbed or washed. While effective, this process is complex, cumbersome, and costly. The use of large powder-shaking machines and the resulting dust not only pollute the working environment but also pose a potential health threat to operators. Furthermore, it does not meet the environmental and high-efficiency production requirements of modern textiles. Additionally, the adhesion and durability of the printed design to the textile during rubbing or washing still need improvement. Summary of the Invention

[0005] Based on this, this application provides a coating ink printing solution, in which a first ink and a second ink are loaded into a multi-head inkjet printer, and as the printer runs, the first ink and the second ink are sequentially sprayed onto the transfer medium.

[0006] The first ink comprises an aqueous nano-polyurethane emulsion;

[0007] The second ink is a transparent ink, which includes water-based hot-melt nano-polyurethane emulsion;

[0008] Water-based hot-melt nano-polyurethane emulsion accounts for 60%-70% of the total mass of transparent ink;

[0009] The elongation of the waterborne nano-polyurethane in the waterborne nano-polyurethane emulsion is 180%-600%.

[0010] The elongation of the waterborne hot-melt nano-polyurethane in the waterborne hot-melt nano-polyurethane emulsion is 1500%-1800%.

[0011] As can be seen from the above scheme, both the water-based nano-polyurethane emulsion in the first ink and the water-based hot-melt nano-polyurethane emulsion in the second ink have a certain elongation, and the elongation of the water-based hot-melt nano-polyurethane solution is greater than that of the water-based nano-polyurethane solution. Firstly, and most fundamentally, the addition of an elongated water-based hot-melt nano-polyurethane emulsion (resin) to the second ink allows for a tighter bond between the ink and the fabric, preventing the pattern from easily deforming or peeling off even after significant deformation such as machine washing and rubbing. Secondly, the addition of a high-elongation water-based hot-melt nano-polyurethane emulsion to the second ink can reduce the ink's viscosity. This is especially important when the water-based hot-melt nano-polyurethane emulsion constitutes a significant portion of the total volume of the transparent ink. When the amount is 60%-70%, the ink can better release stress through deformation, reduce internal friction, make the ink flow more easily, and reduce the risk of ink clogging in the printer, resulting in smooth printing. Therefore, the elongation rate of the water-based hot-melt nano polyurethane emulsion (resin) in the second ink is much higher than that of the resin in existing ordinary inks. Thirdly, the elongation rate of the water-based hot-melt nano polyurethane emulsion in the second ink is greater than that of the water-based nano polyurethane emulsion in the first ink. During the transfer process, because the second ink is heated and deformed first, its high elongation rate allows it to better wrap the first ink while penetrating the fabric, so that the pattern formed by the first ink can be transferred to the fabric completely and efficiently.

[0012] The transparent ink contains 60%-70% water-based hot-melt nano-polyurethane emulsion, far exceeding the content of water-based polyurethane resin in ordinary inks. Generally, existing ordinary inks do not contain more than 30% water-based polyurethane resin; exceeding 30% can easily lead to excessive ink viscosity, printer head clogging, and printing failure. This application uses a specific water-based hot-melt nano-polyurethane emulsion with an elongation of 1500%-1800%, because the high elongation effectively reduces ink viscosity, resulting in smooth printing.

[0013] The optimal addition amount of water-based hot-melt nano-polyurethane emulsion is 60%-70%. If the addition amount is below 60%, the second ink will not effectively bond the fabric to the pattern formed by the first ink during the transfer process, resulting in poor ink wash fastness and easy pattern fading. Conversely, if the addition amount is above 70%, the system viscosity will be too high, making it unsuitable for printing and prone to nozzle clogging.

[0014] The elongation of waterborne nano-polyurethane or waterborne hot-melt nano-polyurethane is the elongation corresponding to its formation of a dry film.

[0015] Optionally, the transfer medium includes transfer film and transfer paper.

[0016] Optionally, the average particle size of the waterborne hot-melt nano-polyurethane emulsion is smaller than that of the waterborne nano-polyurethane emulsion, and the difference is not greater than 50 nm.

[0017] Optionally, the average particle size of the waterborne hot-melt nano-polyurethane emulsion is 40-100 nm;

[0018] The average particle size of the waterborne nano-polyurethane emulsion is 40-120 nm.

[0019] For example, if the average particle size of the aqueous nano-polyurethane emulsion in the first ink is 100 nm, the average particle size of the aqueous hot-melt nano-polyurethane emulsion in the second ink can be selectively controlled to be 70 nm.

[0020] The average particle size of the emulsion described in this application is the average particle size of the solid particles in the emulsion.

[0021] The particle size of the water-based hot-melt nano-polyurethane emulsion is controlled to be smaller than that of the water-based nano-polyurethane emulsion. This is because when the particle size of the water-based hot-melt nano-polyurethane emulsion is smaller, the second ink can have smoother flow and can better encapsulate the first ink during the transfer process.

[0022] Since the first ink and the second ink are printed sequentially, that is, printed on the same inkjet printer with printing intervals measured in seconds, in order to prevent cross-permeation between the two inks under rapid printing conditions, which could damage the pattern formed by the first ink, it is necessary to control the particle size of the water-based hot-melt nano-polyurethane emulsion to be smaller than that of the water-based nano-polyurethane emulsion, and the average particle size difference to be no greater than 50nm.

[0023] Optionally, the first ink includes a colored ink, which, by weight percentage, comprises the following raw materials: 10%-30% water-based nano-polyurethane emulsion, 15%-35% water-based nano-pigment paste, 20%-35% water-based polyol, 0%-7% Class A organic compound, 0.1%-3% pH buffer, 0.1%-5% acetylenic diol surfactant, 0.1%-3% first-blocked isocyanate curing agent, 0.1%-5% organosilicon surfactant, and 0.1%-1% bactericide, with the balance being water;

[0024] Optionally, the aqueous nano-polyurethane emulsion is an anionic aliphatic, low-modulus, high-elasticity, and hydrolysis-resistant aqueous polyurethane dispersion; further optionally, the aqueous nano-polyurethane emulsion is selected from TAKELAC W6110, TAKELAC W6010, TAKELAC W5145, TAKELAC W5310, RESIN-T, and RESIN-8. At least one of DL 1606.

[0025] The colored ink of this application includes four colors. Different water-based nano-pigment pastes of different colors can be selected to obtain the desired ink color. Then, during the printing process, the printer internally selects and mixes different colored inks according to the color of the printed pattern. Specifically, it can use the four basic colors currently available in colored inks for mixing. Theoretically, it is possible to mix and configure hundreds of millions of different colors, thus fully meeting the printing needs of colored patterns in practical applications.

[0026] Optionally, the water-based nano pigment paste is selected from at least one of the CAB-O-JET400, CAB-O-JET450C, CAB-O-465M, CAB-O-470Y series or the K500, M500, C500, Y500 series.

[0027] The aqueous polyol is selected from at least one of glycerol, propylene glycol, ethylene glycol, diethylene glycol, 1,2-hexanediol, 1,5-pentanediol, and isopropanol;

[0028] Class A organic compounds are selected from at least one of 2-pyrrolidone, diethylene glycol monobutyl ether, and triethylene glycol monobutyl ether;

[0029] The pH buffer is selected from at least one of triethanolamine and AMP95;

[0030] The acetylenol surfactant is selected from at least one of Surfynol 465, Surfynol 485, Surfynol 104E, Surfynol 420, and Dynol 604;

[0031] The organosilicon surfactant is selected from at least one of Hydropalat WE3220, Hydropalat WE3221, Hydropalat WE3229, TEGO WET240, TEGO WET260, TEGO WET280, and SAG-503A;

[0032] The bactericide is selected from at least one of LONZA Barquat DM-50 and Nipacide BIT20.

[0033] Optionally, the aqueous nano-polyurethane emulsion is selected from Mitsui Chemicals, Inc. (TAKELAC W6110), Mitsui Chemicals, Inc. (TAKELAC W6010), Mitsui Chemicals, Inc. (TAKELAC W5145), Mitsui Chemicals, Inc. (TAKELAC W5310), Mitsui Chemicals, Inc. (RESIN-T), and Mitsui Chemicals, Inc. (RESIN-8). DL 1606 At least one of Covestro AG;

[0034] The water-based nano pigment paste is selected from at least one of the following series: CAB-O-JET400, CAB-O-JET450C, CAB-O-465M, CAB-O-470Y from Cabot Corporation, USA, or K500, M500, C500, Y500 from Shanghai Yunling Nanomaterials Co., Ltd.

[0035] The pH buffer is selected from at least one of triethanolamine, AMP95, and Dow Inc.

[0036] The acetylenic diol surfactant is selected from at least one of the following: Surfynol 465 (Air Products and Chemicals, Inc.), Surfynol 485 (Air Products and Chemicals, Inc.), Surfynol 104E (Air Products and Chemicals, Inc.), Surfynol 420 (Air Products and Chemicals, Inc.), and Dynol 604 (Air Products and Chemicals, Inc.).

[0037] The organosilicon surfactant is selected from at least one of the following: Hydropalat WE3220 (BASF), Hydropalat WE3221 (BASF), Hydropalat WE3229 (BASF), TEGO WET240 (Evonik Degussa GmbH), TEGO WET260 (Evonik Degussa GmbH), TEGO WET280 (Evonik Degussa GmbH), and SAG-503A (Nissin Chemical Industry CO., Ltd.).

[0038] The fungicide is selected from at least one of LONZA Barquat DM-50 (Lonza Group) and Nipacide BIT20 (Clariant International Ltd.).

[0039] Optionally, the average particle size of the water-based nano pigment paste is <300nm.

[0040] Optionally, the first ink also includes a white ink, which, by weight percentage, comprises the following raw materials: 10%-30% aqueous nano-polyurethane emulsion, 15%-35% aqueous nano-titanium white paste, 20%-35% aqueous polyol, 0.1%-3% pH buffer, 0.1%-5% acetylenic diol surfactant, 0.1%-3% first blocked isocyanate curing agent, 0.1%-5% organosilicon surfactant, and 0.1%-1% bactericide, with the balance being water;

[0041] The average particle size of the water-based nano-titanium white slurry is <300nm.

[0042] White ink does not contain Class A organic compounds compared to colored ink because the water-based nano titanium white paste in white ink has a relatively high solid content. 2-Pyrrolidone is a highly volatile solvent, and using both together can easily cause a dry-head phenomenon, resulting in the printhead being unable to eject ink.

[0043] The average particle size of the aqueous nano-pigment paste described in this application is the average particle size of the colored solid particles in the aqueous nano-pigment paste; the average particle size of the aqueous nano-titanium white paste is the average particle size of the white solid particles in the aqueous nano-titanium white paste.

[0044] Optionally, the preparation steps of the aqueous nano-titanium white slurry include:

[0045] S1: Deionized water, titanium dioxide, pH buffer, polyol, dispersant and bactericide are added to the mixing tank in sequence. The stirring speed is set to 2000-4000 rpm and the mixture is dispersed for 2-5 hours to obtain an aqueous titanium dioxide dispersion.

[0046] S2: Add the titanium dioxide dispersion obtained in step S1 to a grinder with a filling rate of 60-80% for zirconia grinding balls (particle size 0.2-0.5mm) and grind at 2300-3000rpm for 3-5h. After grinding, the average particle size is tested to be <300nm, thus obtaining an aqueous nano titanium dioxide white slurry.

[0047] Optionally, a high molecular weight, controllable polymerizable amphiphilic dispersant with a molecular weight of 2000-5000 can be selected as the dispersant.

[0048] Optionally, by mass percentage, the aqueous nano titanium dioxide slurry comprises the following raw materials: 40-60% titanium dioxide, 0.01-5% pH buffer, 7-20% polyol, 5-15% dispersant, 0.1%-1% bactericide, and the balance being water;

[0049] Optionally, the dispersant is selected from at least one of BYK 2010 BYK Chemie GmbH, TEGO 752W Evonik Degussa GmbH, and AZURM-4884 Lubrizol.

[0050] The titanium dioxide is selected from at least one of the following: titanium dioxide R706 (DuPont), titanium dioxide R960 (DuPont), titanium dioxide R902+ (DuPont), titanium dioxide CR50 (Ishihara Sangyo Kaisha, Ltd.), and titanium dioxide CR60 (Ishihara Sangyo Kaisha, Ltd.).

[0051] The aqueous polyol is selected from at least one of glycerol, propylene glycol, ethylene glycol, diethylene glycol, 1,2-hexanediol, 1,5-pentanediol, and isopropanol;

[0052] The pH buffer is selected from at least one of triethanolamine, AMP95, Dow Chemical Company;

[0053] The fungicide is selected from at least one of LONZA Barquat DM-50 (Lonza Group, Switzerland) and Nipacide BIT20 (Clariant).

[0054] Optionally, the step of sequentially spraying the first ink and the second ink onto the transfer medium includes sequentially spraying colored ink, white ink, and transparent ink onto the transfer medium.

[0055] Specifically, when printing on light-colored fabric, the colored ink of the first ink and the transparent ink of the second ink are printed sequentially;

[0056] Specifically, when printing on dark fabrics, colored ink, white ink, and a second transparent ink are printed sequentially, so that the color of the printed pattern is not affected by the color of the fabric.

[0057] Optionally, the second ink is a transparent ink, comprising, by weight percentage, the following raw materials: 60%-70% water-based hot-melt nano-polyurethane emulsion, 5%-20% water-based polyol, 2%-7% Class A organic compound, 0.1%-3% pH buffer, 0.1%-5% acetylenic diol surfactant, 0.1%-3% second-blocked isocyanate curing agent, 0.1%-5% silicone surfactant, and 0.1%-1% bactericide, with the balance being water.

[0058] Optionally, the aqueous polyol is selected from at least one of glycerol, propylene glycol, ethylene glycol, diethylene glycol, 1,2-hexanediol, 1,5-pentanediol, and isopropanol;

[0059] Class A organic compounds are selected from at least one of 2-pyrrolidone, diethylene glycol monobutyl ether, and triethylene glycol monobutyl ether;

[0060] The pH buffer is selected from at least one of triethanolamine and AMP95;

[0061] The acetylenol surfactant is selected from at least one of Surfynol 465, Surfynol 485, Surfynol 104E, Surfynol 420, and Dynol 604;

[0062] The organosilicon surfactant is selected from at least one of Hydropalat WE3220, Hydropalat WE3221, Hydropalat WE3229, TEGO WET240, TEGO WET260, TEGO WET280, and SAG-503A;

[0063] The bactericide is selected from at least one of LONZA Barquat DM-50 and Nipacide BIT20.

[0064] Optionally, the pH buffer is selected from at least one of triethanolamine, AMP95, and Dow Inc.

[0065] The acetylenic diol surfactant is selected from at least one of the following: Surfynol 465 (Air Products and Chemicals, Inc.), Surfynol 485 (Air Products and Chemicals, Inc.), Surfynol 104E (Air Products and Chemicals, Inc.), Surfynol 420 (Air Products and Chemicals, Inc.), and Dynol 604 (Air Products and Chemicals, Inc.).

[0066] The organosilicon surfactant is selected from at least one of Hydropalat WE3220, Hydropalat WE3221, Hydropalat WE3229, TEGO WET240, TEGO WET260, TEGO WET280, and SAG-503A from Nissin Chemical Industry Co., Ltd.

[0067] The fungicide is selected from at least one of LONZA Barquat DM-50 and Nipacide BIT20 from Clariant International Ltd.

[0068] Optionally, the raw materials for preparing the waterborne hot-melt nano-polyurethane emulsion include, by weight, 50-90 parts of polyol, 20-45 parts of diisocyanate monomer, 1-5 parts of chain extender, 1-9 parts of catalyst and 100-400 parts of deionized water.

[0069] Optionally, the polyol is poly(1,4-butenyl adipate) and poly(neopentyl adipate); the mass ratio of poly(1,4-butenyl adipate) to poly(neopentyl adipate) is (30-45):(20-45);

[0070] The diisocyanate monomers are isoflurone diisocyanate and hexamethylene diisocyanate; the mass ratio of isoflurone diisocyanate to hexamethylene diisocyanate is (10-15):(10-30);

[0071] The chain extenders are dimethylolpropionic acid and small molecule polyols;

[0072] The mass ratio of dimethylolpropionic acid to small molecule polyol is (0.5-3):(0.5-2);

[0073] The small molecule polyol is selected from at least one of ethylene glycol, propylene glycol, 1,4-butanediol, and 1,2-propanediol;

[0074] The catalyst is triethylamine.

[0075] Optionally, the raw materials for preparing the waterborne hot-melt nano-polyurethane emulsion, by weight, include 30-45 parts of poly(1,4-butene adipate), 20-45 parts of polypentyl glycol adipate, 10-15 parts of isoflurane diisocyanate, 10-30 parts of hexamethylene diisocyanate, 0.5-3 parts of dimethylolpropionic acid, 0.5-2 parts of small molecule polyol, 1-9 parts of triethylamine, and 100-400 parts of deionized water.

[0076] Optionally, the preparation steps of the aqueous hot-melt nano-polyurethane emulsion include:

[0077] S1. The polyol is dried and dehydrated, and then mixed with the diisocyanate monomer to form a mixture for the first reaction;

[0078] S2. After the first reaction is completed, a chain extender is added to carry out the second reaction, and then a catalyst is added to carry out the third reaction. After the third reaction is completed, water is added for dispersion, and the mixture is filtered to obtain the water-based hot-melt nano-polyurethane emulsion.

[0079] Optionally, the drying and dehydration temperature is 90-130℃, and the drying and dehydration time is 1-2 hours;

[0080] The first reaction temperature is 60-100℃, and the first reaction time is 3-6 hours;

[0081] The second reaction temperature is 60-100℃, and the second reaction time is 3-5 hours;

[0082] The third reaction temperature is 30-60℃, and the third reaction time is 10-30 min;

[0083] Small molecule polyols are selected from at least one of ethylene glycol, propylene glycol, 1,4-butanediol, and 1,2-propanediol.

[0084] Further optional, the specific preparation steps of the waterborne hot-melt nano-polyurethane emulsion include:

[0085] S1. The polyol poly(1,4-butene adipate) and polypentyl adipate are dried and dehydrated, and then mixed with isoflurane diisocyanate and hexamethylene diisocyanate to form a mixture for the first reaction.

[0086] S2. After the first reaction is completed, dimethylolpropionic acid and small molecule polyol are added to carry out the second reaction. Then triethylamine is added to carry out the third reaction. After the third reaction is completed, water is added for dispersion and filtration to obtain water-based hot melt nano polyurethane emulsion.

[0087] Optionally, the unblocking temperature of the second blocked isocyanate in the second ink is higher than the unblocking temperature of the first blocked isocyanate curing agent in the first ink.

[0088] Optionally, the unsealing temperature of the first blocked isocyanate curing agent in the first ink is 80-120℃, and the unsealing temperature of the second blocked isocyanate curing agent in the second ink is 130-200℃.

[0089] Optionally, the first blocked isocyanate curing agent in the first ink is selected from at least one of Trixene Aqua BI200, BL-8126, and Takenate D-110N.

[0090] Optionally, the first blocked isocyanate curing agent in the first ink is selected from Trixene Aqua BI200 Lanxess Chemicals (China) Co., Ltd. BI7982 Lanxess Chemicals (China) Co., Ltd. At least one of BI7963 Lanxess Chemical (China) Co., Ltd., BL-8124 Guangzhou Guanzhi New Materials Co., Ltd., and Takenate D-110N Mitsui Chemicals Co., Ltd. Optionally, the second blocked isocyanate curing agent in the second ink is selected from: imprafix2794.

[0091] Optionally, the second blocked isocyanate curing agent in the second ink is selected from: imprafix2794 Covestro AG.

[0092] The desealing temperature of the first isocyanate curing agent in the first ink is lower than that of the second isocyanate curing agent in the second ink. During the heat transfer process, the first isocyanate curing agent of the first ink deseales first upon heating, allowing the pattern of the first ink to form and cure quickly. The second isocyanate curing agent of the second ink deseales later. This ensures that the second ink does not affect the formation of the pattern of the first ink, and that the second ink continuously coats and covers the pattern of the first ink during the transfer process, deepening its bond with the fabric. This results in a fabric with stronger wash fastness.

[0093] Optionally, the preparation steps of the colored ink include: stirring and mixing the raw materials of the colored ink, filtering, and obtaining the colored ink;

[0094] The preparation steps of the white ink include: stirring and mixing the raw materials of the white ink, filtering, and obtaining the white ink;

[0095] The preparation steps of the transparent ink include: stirring and mixing the raw materials of the transparent ink, filtering, and obtaining the transparent ink.

[0096] Optionally, the method for preparing the colored ink includes the following steps:

[0097] 1) Deionized water, water-based polyol, Class A organic compound, acetylation diol surfactant, organosilicon surfactant, water-based nano polyurethane emulsion, water-based nano pigment paste, bactericide, first-blocked isocyanate curing agent, and pH buffer are added to a mixing tank in sequence and dispersed. The stirring speed is set to 1000-3000 rpm and the mixture is dispersed for 2-5 hours to obtain pre-dispersed colored ink.

[0098] 2) Filter the pre-dispersed colored ink through a Corbett 0.45pp filter membrane at a negative pressure of 0.01-0.1MPa. After filtering twice, defoam at a negative pressure of 0.01-0.1MPa for 20-60 minutes to obtain the colored ink.

[0099] The method for preparing the white ink includes the following steps:

[0100] 1) Deionized water, water-based polyol, acetylacetonate diol surfactant, organosilicon surfactant, water-based nano polyurethane emulsion, water-based nano titanium white paste, bactericide, first type of blocked isocyanate curing agent, and pH buffer are added to a mixing tank in sequence and dispersed. The stirring speed is set to 1000-3000 rpm and the mixture is dispersed for 2-5 hours to obtain pre-dispersed white ink.

[0101] 2) Filter the pre-dispersed white ink through a Corbett 0.45pp filter membrane at a negative pressure of 0.01-0.1MPa. After filtering twice, defoam at a negative pressure of 0.01-0.1MPa for 20-60 minutes to obtain the white ink.

[0102] The preparation method of the bright ink includes the following steps:

[0103] 1) Deionized water, water-based polyol, Class A organic compound, acetylation diol surfactant, organosilicon surfactant, water-based hot melt nano polyurethane emulsion, bactericide, second-blocked isocyanate curing agent, and pH buffer are added to a mixing tank in sequence and dispersed. The stirring speed is set to 1000-3000 rpm and dispersed for 2-5 hours to obtain a pre-dispersed transparent ink.

[0104] 2) Filter the pre-dispersed transparent ink using a Cobbate 0.45pp filter membrane under negative pressure of 0.01-0.1MPa. After filtering twice, defoam under negative pressure of 0.01-0.1MPa for 20-60 minutes to obtain the transparent ink.

[0105] The technical solution of this application has the following advantages:

[0106] (1) The coating ink printing solution provided in this application involves loading a first ink and a second ink into a multi-head inkjet printer, and sequentially spraying the first ink and the second ink onto the transfer medium as the printer runs; the first ink includes an aqueous nano-polyurethane emulsion; the second ink is a transparent ink, which includes an aqueous hot-melt nano-polyurethane emulsion; the aqueous hot-melt nano-polyurethane emulsion accounts for 60%-70% of the total mass of the transparent ink; the elongation of the aqueous nano-polyurethane in the aqueous nano-polyurethane emulsion is 180%-600%; and the elongation of the aqueous hot-melt nano-polyurethane is 1500%-1800%. This application selects a water-based hot-melt nano-polyurethane emulsion with a specific content and elongation as the raw material for the second ink, and a water-based nano-polyurethane emulsion with a specific elongation as the raw material for the first ink. This results in both the first and second inks having a certain elongation. Since the elongation of the water-based hot-melt nano-polyurethane is greater than that of the water-based nano-polyurethane emulsion, the elongation of the second ink is greater than that of the first ink. During printing, two or three printheads work simultaneously, with printing intervals measured in seconds. This rapid, multi-layer printing method prevents cross-permeation on the transfer film, and the subsequent transfer to the fabric results in a complete pattern. The printing process eliminates the need for a bulky dust-removing machine and generates no dust. It is simple to operate, low in cost, and produces smooth printing with a good tactile feel. Furthermore, the second ink allows for a tighter bond between the fabric and the first ink (the printed colored pattern), enhancing adhesion and durability. Even with rubbing or washing of the fabric, the pattern does not deform or peel off, and it is not prone to fading.

[0107] (2) In the coating ink printing solution provided in this application, the average particle size of the water-based hot-melt nano-polyurethane emulsion is smaller than that of the water-based nano-polyurethane emulsion, and the difference is no greater than 50 nm. Controlling the average particle size of the water-based hot-melt nano-polyurethane emulsion and the water-based nano-polyurethane emulsion and their difference can further ensure printing quality, reduce pattern damage, and make the pattern intact.

[0108] (3) The coating ink printing solution provided in this application uses a second ink that is transparent. By weight percentage, it comprises the following raw materials: 60%-70% water-based hot-melt nano-polyurethane emulsion, 5%-20% water-based polyol, 2%-7% Class A organic compound, 0.1%-3% pH buffer, 0.1%-5% acetylenic diol surfactant, 0.1%-1% blocked isocyanate curing agent, 0.1%-5% organosilicon surfactant, and 0.1%-1% bactericide, with the remainder being water. Specific selection of the composition and specific content of the first ink further improves the adhesion between the ink and the fabric, and the pattern does not deform or easily detach even when the fabric is rubbed.

[0109] (4) The coating ink printing solution provided in this application has a non-hard feel and good color gloss after being hot-stamped on the fabric. Detailed Implementation

[0110] The following embodiments are provided to better understand this application and are not limited to the preferred embodiments described herein. They do not constitute a limitation on the content and scope of protection of this application. Any product that is the same as or similar to this application, derived by anyone under the guidance of this application or by combining the features of this application with other related technologies, falls within the scope of protection of this application.

[0111] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0112] Example 1

[0113] This embodiment provides a coating ink printing solution: a first ink and a second ink are loaded into a multi-head inkjet printer, wherein the first ink includes colored ink and white ink, and the second ink is transparent ink. As the printer runs, colored ink, white ink and transparent ink are sequentially sprayed onto the transfer medium.

[0114] The colored ink, by weight percentage, comprises the following raw materials: 25% water-based nano-polyurethane emulsion TAKELAC W6110 (average particle size 100nm), 20% water-based nano-pigment paste, 8% glycerol, 20% ethylene glycol, 5% Class A organic compound 2-pyrrolidone, 0.5% pH buffer AMP95, 1% acetylsene diol surfactant Surfnol 465, 3% first-blocked isocyanate curing agent Takenate D-110N, 0.3% organosilicon surfactant TEGO WET260, and 0.1% bactericide Nipacide BIT20, with the balance being deionized water (depending on the selection of different water-based nano-pigment pastes, the colored ink includes black ink, blue ink, red ink, and yellow ink); specific raw materials and contents are detailed in Table 1; the elongation of the water-based nano-polyurethane in the water-based nano-polyurethane emulsion is 560%;

[0115] The white ink, by weight percentage, comprises the following raw materials: 25% water-based nano-polyurethane emulsion TAKELAC W6110, 20% water-based nano-titanium white paste, 5% glycerol, 15% ethylene glycol, 0.5% pH buffer AMP95, 1% acetylsene glycol surfactant Surfnol 465, 3% first-blocked isocyanate curing agent Takenate D-110N, 0.5% silicone surfactant TEGO WET260, and 0.1% bactericide Nipacide BIT20, with the balance being deionized water; for details of the raw materials and their contents, please refer to Table 2.

[0116] The preparation method of water-based nano-titanium white paste includes the following steps:

[0117] By mass percentage, 27.3% deionized water, 50% titanium dioxide R960 (DuPont), 0.1% pH buffer AMP95, 10% diethylene glycol, 12.5% ​​dispersant BYK 2010, and 0.1% bactericide Nipacide BIT20 were sequentially added to a mixing tank. The mixing speed was set to 3000 rpm, and the mixture was dispersed for 4 hours to obtain an aqueous titanium dioxide dispersion. The obtained aqueous titanium dioxide dispersion was added to a mill with a zirconia grinding ball (particle size 0.3 mm) filling rate of 75%, and ground at 2500 rpm for 4 hours. The average particle size was tested to be <300 nm, thus obtaining an aqueous nano titanium dioxide slurry.

[0118] The transparent ink, by weight percentage, comprises the following raw materials: 65% water-based hot-melt nano-polyurethane emulsion, 10% ethylene glycol, 3% 2-pyrrolidone, 0.5% pH buffer AMP95, 1% acetylenic diol surfactant Surfnol 465, 3% second-blocked isocyanate curing agent imprafix 2794, 0.5% silicone surfactant TEGO WET 260, and 0.1% bactericide Nipacide BIT 20, with the balance being deionized water; for details of the raw materials and their contents, please refer to Table 3.

[0119] The elongation of the waterborne hot-melt nano-polyurethane in the waterborne hot-melt nano-polyurethane emulsion is 1600%.

[0120] The raw materials for preparing the water-based hot-melt nano-polyurethane emulsion, by weight, include: 35 parts poly(1,4-butene adipate), 25 parts polypentyl adipate neopentyl glycol ester, 10 parts isoflurane diisocyanate, 22 parts hexamethylene diisocyanate, 3 parts dimethylolpropionic acid, 2 parts ethylene glycol, 7 parts triethylamine, and 300 parts deionized water.

[0121] The method for preparing the water-based hot-melt nano-polyurethane emulsion includes the following steps:

[0122] S1. 35 parts of polyol poly(1,4-butene adipate) and 25 parts of polypentyl adipate were dried and dehydrated at 110°C for 1.5 h. Then, after cooling to 60°C, a mixture of 10 parts of isoflurone diisocyanate and 22 parts of hexamethylene diisocyanate was added and reacted at 76°C for 5 h.

[0123] S2. Add 3 parts of dimethylolpropionic acid and 2 parts of ethylene glycol, and continue the reaction at 76℃ for 5 hours. Cool to 50℃ and add 7 parts of triethylamine. After reacting for 20 minutes, add 300 parts of deionized water to disperse, obtaining an aqueous polyurethane emulsion. Filter the obtained aqueous polyurethane emulsion once with a 1.0-micron PP filter from a Corbett filter, and then once with a 0.45-micron PP filter from a Corbett filter to obtain the aqueous nano-thermal melt polyurethane emulsion. The average particle size of the prepared aqueous nano-thermal melt polyurethane emulsion is 70 nm.

[0124] Table 1

[0125] Table 2

[0126] Table 3

[0127] The preparation method of the above-mentioned colored ink includes the following steps:

[0128] 1) Deionized water, water-based polyol, Class A organic compound, acetylation diol surfactant, organosilicon surfactant, water-based nano polyurethane emulsion, water-based nano pigment paste, bactericide, first type of blocked isocyanate curing agent, and pH buffer are added to a mixing tank in sequence and dispersed. The stirring speed is set to 2000 rpm and the mixture is dispersed for 4 hours to obtain pre-dispersed colored ink.

[0129] 2) The pre-dispersed colored ink was filtered twice using a Corbett 0.45pp filter membrane under a negative pressure of 0.08MPa. After filtration, the ink was defoamed under a negative pressure of 0.08MPa for 30 minutes to obtain the colored ink.

[0130] The preparation method of the above-mentioned white ink includes the following steps:

[0131] 1) Deionized water, waterborne polyol, acetylacetonate diol surfactant, organosilicon surfactant, waterborne nano polyurethane emulsion, waterborne nano titanium white paste, bactericide, first type of blocked isocyanate curing agent, and pH buffer were added to a mixing tank in sequence and dispersed. The stirring speed was set to 2000 rpm and the mixture was dispersed for 4 hours to obtain pre-dispersed white ink.

[0132] 2) The pre-dispersed white ink was filtered through a Corbett 0.45pp filter membrane at a negative pressure of 0.08MPa. After filtration twice, the ink was defoamed at a negative pressure of 0.08MPa for 30 minutes to obtain the white ink.

[0133] The preparation method of the above-mentioned transparent ink includes the following steps:

[0134] 1) Deionized water, water-based polyol, type A organic compound, acetylation diol surfactant, organosilicon surfactant, water-based hot melt nano polyurethane emulsion, bactericide, second type blocked isocyanate curing agent, and pH buffer were added to a mixing tank in sequence and dispersed. The stirring speed was set to 2000 rpm and the mixture was dispersed for 4 hours to obtain a pre-dispersed transparent ink.

[0135] 2) The pre-dispersed transparent ink was filtered twice using a Corbett 0.45pp filter membrane under a negative pressure of 0.08MPa. After filtration, the ink was defoamed under a negative pressure of 0.08MPa for 30 minutes to obtain the transparent ink.

[0136] Example 2

[0137] This embodiment provides a coating ink printing solution, which differs from Embodiment 1 only in the raw material content of the transparent ink, as detailed in Table 4.

[0138] Table 4

[0139] Example 3

[0140] This embodiment provides a coating ink printing solution, which differs from Embodiment 1 only in the raw material content of the transparent ink, as detailed in Table 5.

[0141] Table 5

[0142] Example 4

[0143] This embodiment provides a coating ink printing solution: a first ink and a second ink are loaded into a multi-head inkjet printer, wherein the first ink is a colored ink, and as the printer runs, colored ink and transparent ink are sequentially sprayed onto the transfer medium;

[0144] The raw material content and preparation method of colored ink and transparent ink are the same as in Example 1.

[0145] Example 5

[0146] This embodiment provides a coating ink printing solution, which differs from Embodiment 1 in that the raw materials and contents of colored ink, white ink and transparent ink are different. The raw materials and contents of colored ink are detailed in Table 6, the raw materials and contents of white ink are detailed in Table 7, and the raw materials and contents of transparent ink are detailed in Table 8.

[0147] Table 6

[0148] Table 7

[0149] Table 8

[0150] Example 6

[0151] This embodiment provides a coating ink printing solution, which differs from Embodiment 1 in that the raw materials and contents of colored ink, white ink and transparent ink are different. The raw materials and contents of colored ink are detailed in Table 9, the raw materials and contents of white ink are detailed in Table 10, and the raw materials and contents of transparent ink are detailed in Table 11.

[0152] Table 9

[0153] Table 10

[0154] Table 11

[0155] Example 7

[0156] This embodiment provides a coating ink printing solution, which differs from Embodiment 1 only in that the water-based hot-melt nano-polyurethane emulsion preparation method includes the following steps:

[0157] S1. 35 parts of polyol poly(1,4-butene adipate) and 25 parts of polypentyl adipate were dehydrated at 110°C for 1.5 h, and then cooled to 60°C and a mixture of 10 parts of isoflurane diisocyanate and 22 parts of hexamethylene diisocyanate was added. The mixture was reacted at 105°C for 3 h.

[0158] S2. Add 3 parts of dimethylolpropionic acid and 2 parts of ethylene glycol, and continue the reaction at 105℃ for 3.5 h. Cool down to 50℃ and add 7 parts of triethylamine. After reacting for 20 minutes, add 300 parts of deionized water to disperse, obtaining an aqueous polyurethane emulsion. Filter the obtained aqueous polyurethane emulsion once with a 1.0-micron PP filter from a Corbett filter, and then once with a 0.45-micron PP filter from a Corbett filter to obtain an aqueous nano-hot-melt polyurethane emulsion. The average particle size of the prepared aqueous nano-hot-melt polyurethane emulsion is 36 nm.

[0159] Comparative Example 1

[0160] This comparative example provides a coating ink printing solution, which differs from Example 1 only in that the water-based hot-melt nano-polyurethane emulsion in the transparent ink raw material component is replaced by an equal mass of TAKELAC WS-6021 (manufacturer: Mitsui Chemicals, Inc.). The average particle size of TAKELAC WS-6021 is 90 nm, and the elongation of the water-based nano-polyurethane in TAKELAC WS-6021 is 750%.

[0161] Comparative Example 2

[0162] This comparative example provides a coating ink printing solution, which differs from Example 1 only in that the water-based nano-polyurethane emulsion TAKELAC W6110 in the colored ink is replaced with TAKELAC WS-6021 by an equal mass, and the water-based nano-polyurethane emulsion TAKELAC W6110 in the white ink is replaced with TAKELAC WS-6021 by an equal mass; the average particle size of TAKELAC WS-6021 is 90 nm, and the elongation of the water-based nano-polyurethane in TAKELAC WS-6021 is 750%.

[0163] Comparative Example 3

[0164] This comparative example provides a coating ink printing solution, which differs from Example 1 only in the content of raw material components in the transparent ink, as detailed in Table 12;

[0165] Table 12

[0166] Comparative Example 4

[0167] This comparative example provides a coating ink printing solution, which differs from Example 1 only in the content of raw material components in the transparent ink, as detailed in Table 13;

[0168] Table 13

[0169] Test case

[0170] The following tests were conducted based on the coating ink printing solutions provided in Examples 1-7 and Comparative Examples 1-4 of this application:

[0171] 1. Printing smoothness test:

[0172] Color blocks were printed on PET transfer film using an inkjet printer according to the coating ink printing schemes provided in Examples 1-7 and Comparative Examples 1-4. A single yellow ink was selected as the color ink to print solid yellow color blocks. Continuous inkjet printing was performed for 50m at 100% inkjet setting, and the printing smoothness was observed during printing. The printing smoothness test results are shown in Table 14.

[0173] 2. Hand feel test:

[0174] Color blocks were printed on PET transfer film using an inkjet printer according to the ink printing schemes provided in Examples 1-7 and Comparative Examples 1-4. A single yellow ink was selected to print solid yellow color blocks. These blocks were then pressed onto cotton cloth at 150°C. The printing effect was assessed by observing the print with a handheld magnifying glass and by rubbing the print. The judgment criteria included: Definition A: Good feel, the printed pattern is exquisite and flawless; Definition B: Stiff feel, the printed pattern is flawless; Definition C: Not stiff feel, but the printed pattern has poor clarity and resolution, and defects such as size disproportion, missing details, and color bleeding compared to the original image; Definition D: Stiff feel, and the printed pattern has poor clarity and resolution, and defects such as size disproportion, missing details, and color bleeding compared to the original image. The feel test results are shown in Table 14.

[0175] 3. Abrasion resistance test and wash fastness test:

[0176] Color blocks were printed on PET transfer film using an inkjet printer according to the ink printing schemes provided in Examples 1-7 and Comparative Examples 1-4. A single yellow ink was selected to print solid yellow color blocks. These blocks were then pressed onto cotton fabric at 150℃-180℃ and tested according to the dry / wet rubbing color fastness test method specified in GB / T3920-2008. The test results were compared with five levels of gray scale for staining to determine the rubbing fastness. A higher rubbing fastness value indicates better rubbing fastness (3-4 indicates a value between 3 and 4, and the same applies to 1-2 and 2-3). The test results are shown in Table 14.

[0177] The color fastness to washing was tested on the samples according to GB / T 5713-2013. The test results were judged based on the color difference between the original sample and the sample after fading, using a gray scale for color change. The higher the value, the better the color fastness to washing (where 4-5 indicates between grade 4 and grade 5, and the same applies to 1-2, 2-3, and 3-4). The test results are shown in Table 14.

[0178] Table 14

[0179] As can be seen from the test data in the table, in Examples 1-6 of this application, using a water-based hot-melt nano-polyurethane emulsion with a specific content and elongation as the raw material for the second ink, and a water-based nano-polyurethane emulsion with a specific elongation as the raw material for the first ink, the printing smoothness, the feel of the printed object, the abrasion resistance, and the wash fastness are all superior to the comparative examples. It is evident that the printed pattern adheres more tightly to the fabric, and the adhesion and durability are significantly enhanced. In Example 7, when the particle size of the water-based hot-melt nano-polyurethane emulsion in the second ink is changed, the average particle size difference between it and the water-based nano-polyurethane emulsion in the first ink is greater than 50 nm, which affects the feel of the printed object and the wash fastness. In Comparative Examples 1 and 2, the water-based hot-melt nano-polyurethane emulsion in the second ink and the first ink were changed respectively. The water-based nano-polyurethane emulsion in the first ink has altered extensibility, resulting in inferior printing smoothness, print feel, abrasion resistance, and wash fastness compared to the examples. Specifically, the printed pattern in Comparative Example 2 has poor clarity because the extensibility of the first ink is greater than 600%, making the resin in the ink prone to deformation. This leads to inaccurate ink jetting, significantly reducing the precision and resolution of the printed pattern, making it impossible to obtain a refined image. In Comparative Example 3, the second ink contains less than 60% water-based hot-melt nano-polyurethane emulsion, resulting in reduced color fastness / grade in abrasion and wash fastness, affecting adhesion. In Comparative Example 4, the second ink contains more than 70% water-based hot-melt nano-polyurethane emulsion, making the viscosity too high for printing.

[0180] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A coating ink printing solution, characterized in that, A first ink and a second ink are loaded into a multi-head inkjet printer. As the printer runs, the first ink and the second ink are sequentially sprayed onto the transfer medium. The first ink comprises an aqueous nano-polyurethane emulsion; The second ink is a transparent ink, which includes a water-based hot-melt nano-polyurethane emulsion; The water-based hot-melt nano-polyurethane emulsion accounts for 60%-70% of the total mass of the transparent ink; The elongation of the aqueous nano-polyurethane in the aqueous nano-polyurethane emulsion is 180%-600%. The elongation of the water-based hot-melt nano-polyurethane emulsion is 1500%-1800%.

2. The coating ink printing solution according to claim 1, characterized in that, The average particle size of the waterborne hot-melt nano-polyurethane emulsion is smaller than that of the waterborne nano-polyurethane emulsion, and the difference is no more than 50 nm.

3. The coating ink printing solution according to claim 1 or 2, characterized in that, The first ink comprises colored ink, by weight percentage, the colored ink It includes the following raw materials: 10%-30% water-based nano-polyurethane emulsion, 15%-35% water-based nano-pigment paste, 20%-35% water-based polyol, 0%-7% Class A organic compound, 0.1%-3% pH buffer, 0.1%-5% acetylenic diol surfactant, 0.1%-3% first-blocked isocyanate curing agent, 0.1%-5% organosilicon surfactant and 0.1%-1% bactericide, with the balance being water.

4. The coating ink printing solution according to claim 3, characterized in that, The first ink also includes white ink, which, by mass percentage, comprises the following raw materials: 10%-30% water-based nano-polyurethane emulsion, 15%-35% water-based nano-titanium white paste, 20%-35% water-based polyol, 0.1%-3% pH buffer, 0.1%-5% acetylenic diol surfactant, 0.1%-3% first blocked isocyanate curing agent, 0.1%-5% organosilicon surfactant, and 0.1%-1% bactericide, with the balance being water; The average particle size of the aqueous nano-titanium white slurry is <300nm.

5. The coating ink printing solution according to claim 4, characterized in that, The step of sequentially spraying the first ink and the second ink onto the transfer medium includes sequentially spraying colored ink, white ink, and transparent ink onto the transfer medium.

6. The coating ink printing solution according to claim 1, characterized in that, The second ink is a transparent ink, comprising, by weight percentage, the following raw materials: 60%-70% water-based hot-melt nano-polyurethane emulsion, 5%-20% water-based polyol, 2%-7% Class A organic compound, 0.1%-3% pH buffer, 0.1%-5% acetylenic diol surfactant, 0.1%-3% second-blocked isocyanate curing agent, 0.1%-5% organosilicon surfactant, and 0.1%-1% bactericide, with the balance being water.

7. The coating ink printing solution according to any one of claims 1, characterized in that, The aqueous nano-polyurethane emulsion is selected from TAKELAC W6110, TAKELAC W6010, TAKELAC W5145, TAKELAC W5310, RESIN-T, and RESIN-8. At least one of DL 1606.

8. The coating ink printing solution according to claim 1, characterized in that, The raw materials for preparing the water-based hot-melt nano-polyurethane emulsion, by weight, include 50-90 parts of polyol, 20-45 parts of diisocyanate monomer, 1-5 parts of chain extender, 1-9 parts of catalyst and 100-400 parts of water. Optionally, the polyol is poly(1,4-butenyl adipate) and poly(neopentyl adipate); the mass ratio of poly(1,4-butenyl adipate) to poly(neopentyl adipate) is (30-45):(20-45); The diisocyanate monomers are isoflurone diisocyanate and hexamethylene diisocyanate; the mass ratio of isoflurone diisocyanate to hexamethylene diisocyanate is (10-15):(10-30); The chain extender is dimethylolpropionic acid and a small molecule polyol; the mass ratio of dimethylolpropionic acid to the small molecule polyol is (0.5-3):(0.5-2); The small molecule polyol is selected from at least one of ethylene glycol, propylene glycol, 1,4-butanediol, and 1,2-propanediol; The catalyst is triethylamine.

9. The coating ink printing solution according to claim 8, characterized in that, The preparation steps of the water-based hot-melt nano-polyurethane emulsion include: S1. The polyol is dried and dehydrated, and then mixed with the diisocyanate monomer to form a mixture for the first reaction; S2. After the first reaction is completed, a chain extender is added to carry out the second reaction, and then a catalyst is added to carry out the third reaction. After the third reaction is completed, water is added for dispersion, and the mixture is filtered to obtain the water-based hot-melt nano-polyurethane emulsion. Optionally, the drying and dehydration temperature is 90-130℃, and the drying and dehydration time is 1-2 hours; The first reaction temperature is 60-100℃, and the first reaction time is 3-6 hours; The second reaction temperature is 60-100℃, and the second reaction time is 3-5 hours; The third reaction temperature is 30-60℃, and the third reaction time is 10-30 min.

10. The coating ink printing solution according to any one of claims 6-9, characterized in that, The desealing temperature of the second blocked isocyanate curing agent in the second ink is higher than that of the first blocked isocyanate curing agent in the first ink.

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