Inkjet printing consumables and preparation method and application thereof

Abstract

The present invention discloses inkjet printing consumables and a preparation method and application thereof. The inkjet printing consumables include a support and a composite functional layer, the composite functional layer is arranged on at least one surface of the support, the composite functional layer includes at least three sub-functional layers, each sub-functional layer independently includes inorganic particles and a binder, and the at least three sub-functional layers are arranged layer by layer in a direction away from the support, and in the direction away from the support, the true porosity of the at least three sub-functional layers decreases layer by layer. The inkjet printing consumables not only have good scratch resistance, and are not prone to the problems of "whitening", "bright spots" or "bright bands" during production and use, but also have the advantages of high gloss, high color density, good ink absorption and strong ink adaptability.

Description

Technical Field

[0001] The present invention relates to the field of inkjet printing, and in particular to inkjet printing consumables and a preparation method and application thereof. Background Art

[0002] In recent years, with the increasingly serious environmental problems, people pay more and more attention to environmental protection and try to reduce the emission of pollutants, which has limited the development of the traditional silver halide imaging industry to a certain extent. Inkjet printing technology has less pollutant emissions and is environmentally friendly. The quality of the printed images can reach the level of traditional silver halide photos. Therefore, the use of inkjet printing to output images has gradually become a new favorite in the imaging field. Inkjet printing media can form a color image on the coating surface by absorbing and fixing the ink ejected by the printer. However, during the coating production process and the finishing and cutting process, the friction between the inkjet printing consumables and the transmission roller or flip roller surface will produce "whitening" on the consumable surface and "bright spots" on the coating surface. In addition, during the printing process of the inkjet printer, the friction between the stacked inkjet printing consumables when loading paper and the friction between the inkjet printing consumables and the transmission wheel during the transportation process in the inkjet printing consumables printer will also produce "whitening" on its surface, forming "bright spots" or "bright bands" on the coating surface. Summary of the invention

[0003] This application is mainly based on the following questions and findings:

[0004] In order to improve the ink absorption of inkjet printing consumables, the coatings of current printing consumables are mostly designed with microporous structures. The porous ink absorption functional layer can quickly absorb ink to ensure that the ink dries quickly on its surface. However, the presence of a large number of pores leads to a decrease in the mechanical strength of the coating. When the coating is subjected to a certain pressure, the pore structure is squeezed, resulting in a fine and smooth surface formed locally with enhanced reflective ability, thus causing problems such as "whitening", "bright spots" or "light bands". At present, there are proposals to solve the above-mentioned problems by improving the scratch resistance of the surface of inkjet printing media. For example, there is a method of improving the scratch resistance of the coating surface by a process of segmented drying and heat treatment after coating the paper base. However, the composition of the inkjet coating does not change in this method. The segmented drying and heat treatment can only promote the reaction speed of the crosslinking agent and the adhesive and shorten the construction period, but cannot fundamentally improve the scratch resistance of the surface, and cannot avoid the problem of "whitening". For another example, nanocellulose is added to the scratch resistance functional layer of inkjet printing paper, and a three-dimensional network structure is formed in the coating by nanocellulose to enhance the fastness and hardness of the coating, thereby achieving the purpose of improving the friction resistance and scratch resistance of the coating. However, since nanocellulose will cause the glossiness of the coating to decrease, the printed photos will not be bright enough, and the hardness of the photo paper obtained in this method can only reach 4H pencil hardness, and this improvement in hardness will not solve the problems of "whitening" and "bright spots" of the coating.

[0005] In view of this, the present invention aims to solve the technical problems in the related art at least to a certain extent. To this end, the purpose of the present invention is to provide an inkjet printing consumable and a preparation method and application thereof. The inkjet printing consumable not only has good scratch resistance, is not prone to the problems of "whitening", "bright spots" or "bright bands" during production and use, but also has the advantages of high gloss, high color density, good ink absorption and strong ink adaptability.

[0006] In one aspect of the present invention, the present invention provides an inkjet printing consumable. According to an embodiment of the present invention, the inkjet printing consumable includes a support and a composite functional layer, the composite functional layer is arranged on at least one surface of the support, the composite functional layer includes at least three sub-functional layers, each of the sub-functional layers independently includes inorganic particles and a binder, the at least three sub-functional layers are arranged layer by layer in a direction away from the support, and in the direction away from the support, the true porosity of the at least three sub-functional layers decreases layer by layer.

[0007] The inkjet printing consumables of the above-mentioned embodiment of the present invention have at least the following advantages: on the one hand, by decreasing the true porosity of the multi-layer sub-functional layers in the direction away from the support body in sequence, the mechanical strength in the functional layer forms a "pyramid" structure, providing a "pyramid" type structural support. When the coating is subjected to a certain external pressure, the mechanical support of the "pyramid" type structure is more stable, thereby protecting the pore structure in the functional layer from deformation, so that the surface of the consumables remains original, the reflective ability does not change, and there will be no problems of "whitening", "bright spots" or "bright bands". As a result, the process of coating with a protective film in the later stage can be omitted, and no coating is required, which greatly saves production costs. On the other hand, in the composite functional layer, the innermost sub-functional layer in direct contact with the support body has the highest true porosity, which helps to improve The ink absorption capacity of the functional layer enables it to absorb ink quickly, which can not only improve printing efficiency but also will not reduce image density, so that the printed image has the advantages of high color density, bright colors, and good color reproduction, which can meet the image-level image requirements; at the same time, in the composite functional layer, the outermost sub-functional layer farthest from the support has the smallest true porosity, which can not only improve the scratch resistance of the consumables, but also help to improve the glossiness of the coating surface, so that the printed image has a better gloss texture; in addition, the above-mentioned composite functional layer structure with decreasing true porosity layer by layer also makes the consumables have better ink absorption, which can avoid the problem of ink accumulation caused by poor ink penetration and thus affect the quality of the printed image. At the same time, it can also have good adaptability to ink and can adapt to both dye ink and pigment ink.

[0008] In addition, the inkjet printing consumables according to the above embodiment of the present invention may also have the following additional technical features:

[0009] In some embodiments of the present invention, the at least three sub-functional layers are formed by drying a coating slurry, the coating slurry of each sub-functional layer independently includes inorganic particles, a binder and a solvent, and the static surface tension of the coating slurry of each sub-functional layer is independently 15 to 45 mN / m.

[0010] In some embodiments of the present invention, in a direction away from the support, the mass ratio of the inorganic particles to the binder in the at least three sub-functional layers decreases layer by layer.

[0011] In some embodiments of the present invention, in a direction away from the support, the static surface tension of the coating slurry of the at least three sub-functional layers decreases layer by layer.

[0012] In some embodiments of the present invention, in a direction away from the support, the thicknesses of the at least three sub-functional layers decrease layer by layer.

[0013] In some embodiments of the present invention, the support has a thickness of 50 to 400 μm.

[0014] In some embodiments of the present invention, the inorganic particles in each of the sub-functional layers independently include at least one selected from zinc oxide, silicon dioxide, silica sol, aluminum oxide, calcium carbonate, china clay, and barium sulfate.

[0015] In some embodiments of the present invention, the particle size of the inorganic particles in each sub-functional layer is independently 0.05-10 μm.

[0016] In some embodiments of the present invention, the coating slurry of each sub-functional layer further independently includes at least one selected from a dispersant, a leveling agent and a cross-linking agent.

[0017] In some embodiments of the present invention, the adhesive in each of the sub-functional layers is independently a water-based adhesive.

[0018] In some embodiments of the present invention, the solvent in each of the sub-functional layers independently includes an organic solvent and / or water.

[0019] In some embodiments of the present invention, in the direction away from the support, the outermost sub-functional layer further includes a compound having a cationic group, and the added amount of the compound having a cationic group is 5 to 80 wt % of the mass of the inorganic particles in the sub-functional layer.

[0020] In some embodiments of the present invention, the support includes at least one of a base paper, a plastic-coated paper, polypropylene, polyethylene terephthalate, polyvinyl chloride, triacetate film, polyethylene, polycarbonate, and polybutylene terephthalate.

[0021] In some embodiments of the present invention, the aqueous adhesive includes at least one selected from polyvinyl alcohol resin, cellulose resin, polyvinyl pyrrolidone, starch, pullulan, gelatin, polyimide, polyurethane, polystyrene, polymethacrylate, polyacrylic acid, and polybismaleimide.

[0022] In some embodiments of the present invention, the boiling point of the organic solvent is not greater than 200°C.

[0023] In some embodiments of the present invention, the organic solvent includes at least one selected from alcohol solvents, ketone solvents, ester solvents, and amide solvents.

[0024] In some embodiments of the present invention, the dispersant includes at least one selected from hydrochloric acid, nitric acid, boric acid, sulfuric acid, carbonic acid, phosphoric acid, citric acid, malic acid, tartaric acid, acetic acid, succinic acid, oxalic acid, sulfonic acid, lactic acid, formic acid, acetic acid, and propionic acid.

[0025] In some embodiments of the present invention, the leveling agent includes at least one selected from acetylene-based leveling agents, fluorine-based leveling agents, silicone-based leveling agents, polyether-modified silicone-based leveling agents, polysiloxane-based leveling agents, ether-modified polysiloxane-based leveling agents, and polyoxyethylene ether active agents.

[0026] In some embodiments of the present invention, the cross-linking agent includes at least one selected from formaldehyde, glyoxal, boric acid, borax, polyisocyanate, and aziridine.

[0027] In some embodiments of the present invention, the compound having a cationic group includes at least one selected from polypropyleneamine, diethylenetriamine, dipropylenetriamine, triethylenetetramine, cationized polyvinyl alcohol, cationic starch, polyethyleneimine, allylamine, diallyl alkyl polymer, triethylbenzylammonium chloride, trimethylhexadecylammonium hydroxide, dodecyldimethylbenzylammonium bromide, aluminum nitrate, and aluminum chloride.

[0028] In some embodiments of the present invention, in the direction away from the support, the inorganic particles in the outermost sub-functional layer are silica sol and / or silica powder; and / or the particle size of the inorganic particles in the outermost sub-functional layer is 50 to 200 nm.

[0029] In some embodiments of the present invention, the composite functional layer includes three sub-functional layers, and the three sub-functional layers are arranged layer by layer in a direction away from the support.

[0030] In some embodiments of the present invention, in the direction away from the support body, the true porosity of the three-layer sub-functional layer is: 40-80%, 20-40%, 2-20%; and / or the thickness of the three-layer sub-functional layer is: 20-40μm, 10-20μm, 0.1-10μm.

[0031] In some embodiments of the present invention, the three sub-functional layers are successively the first sub-functional layer, the second sub-functional layer and the third sub-functional layer along the direction away from the support body, and the three sub-functional layers satisfy at least one of the following conditions: the inorganic particles in the first sub-functional layer are aluminum oxide and / or silicon dioxide; the inorganic particles in the second sub-functional layer are aluminum oxide and / or silicon dioxide; the inorganic particles in the third sub-functional layer are silica sol and / or silicon dioxide powder; the particle size of the inorganic particles in the third sub-functional layer is 50 to 200 nm.

[0032] In some embodiments of the present invention, the coating slurry of the first sub-functional layer includes: 15 to 30 parts by weight of the inorganic particles, 0.3 to 3 parts by weight of a dispersant, 1 to 2 parts by weight of an aqueous adhesive, 0.5 to 1 part by weight of a leveling agent, 10 to 20 parts by weight of an organic solvent, 0.03 to 0.3 parts by weight of a cross-linking agent, and 41 to 73.17 parts by weight of water.

[0033] In some embodiments of the present invention, the coating slurry of the second sub-functional layer includes: 15 to 30 parts by weight of the inorganic particles, 0.3 to 3 parts by weight of a dispersant, 1.5 to 3 parts by weight of an aqueous adhesive, 0.5 to 2 parts by weight of a leveling agent, 5 to 15 parts by weight of an organic solvent, 0.03 to 0.3 parts by weight of a cross-linking agent, and 44 to 77.67 parts by weight of water.

[0034] In some embodiments of the present invention, the coating slurry of the third sub-functional layer includes: 1 to 10 parts by weight of the inorganic particles, 0.01 to 0.1 parts by weight of a dispersant, 0.5 to 2 parts by weight of an aqueous adhesive, 0.5 to 2 parts by weight of a leveling agent, 5 to 15 parts by weight of an organic solvent, 0.1 to 2 parts by weight of a cross-linking agent, and 65.9 to 93.64 parts by weight of water.

[0035] In another aspect of the present invention, a method for preparing inkjet printing consumables is proposed. According to an embodiment of the present invention, the method comprises: forming at least three sub-functional layers on at least one surface of a support body in a direction away from the support body, and in the direction away from the support body, the true porosity of the at least three sub-functional layers decreases layer by layer. The characteristics and effects described for the above-mentioned inkjet printing consumables are also applicable to the method for preparing inkjet printing consumables, which will not be repeated here. In general, compared with the prior art, this method not only has a simple production process, but also can save the process of coating with a protective film in the later stage, realize the purpose of free coating, and greatly simplify the production process and reduce the production cost. In addition, the inkjet printing consumables prepared have good ink absorption and ink adaptability, high gloss on the coating surface, good scratch resistance, and will not cause "whitening", "bright spots" or "bright bands" during production and use.

[0036] In some embodiments of the present invention, the at least three sub-functional layers are simultaneously coated using a slide extrusion coating device.

[0037] In some embodiments of the present invention, a drying process is further included after the coating is completed. The drying process includes cold air drying and hot air drying performed in sequence. The hot air temperature gradient used in the hot air drying process increases.

[0038] In another aspect of the present invention, a printing product is provided. According to an embodiment of the present invention, the printing product includes the above-mentioned inkjet printing consumables or the inkjet printing consumables prepared by the above-mentioned method. The characteristics and effects described for the above-mentioned inkjet printing consumables and the above-mentioned method for preparing inkjet printing consumables are also applicable to the printing product, and will not be repeated here. In general, compared with the prior art, the printing product not only has excellent scratch resistance, and will not produce problems of "whitening", "bright spots" or "bright bands" during production and use, but also has a higher glossiness, has the advantages of high color density, bright image colors, and good color reproduction, can meet the gloss texture and image-level image requirements comparable to photos, and has better overall quality.

[0039] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0041] Figure 1 is a schematic structural diagram of an inkjet printing consumable according to an embodiment of the present invention;

[0042] Figure 22 is a schematic structural diagram of an inkjet printing consumable according to another embodiment of the present invention. DETAILED DESCRIPTION

[0043] Embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and cannot be construed as limiting the present invention. If specific techniques or conditions are not indicated in the embodiments, the techniques or conditions described in the literature in this field or the product instructions shall be followed. It should be noted that, in the present invention, the terms "first", "second", and "third" are only used for descriptive purposes, and cannot be construed as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first", "second", and "third" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0044] In one aspect of the present invention, the present invention provides an inkjet printing consumable. Figure 1 Or 2 understands that the inkjet printing consumables include a support 10 and a composite functional layer 20, the composite functional layer 20 is arranged on at least one surface of the support 10, the composite functional layer 20 includes at least three sub-functional layers, each sub-functional layer independently includes inorganic particles and a binder, and each sub-functional layer is arranged layer by layer in a direction away from the support 10 (refer to Figure 1 It is understood that each sub-functional layer can be named as the first sub-functional layer 21, the second sub-functional layer 22, the third sub-functional layer 23...) in the direction away from the support body 10, and the true porosity of each sub-functional layer decreases layer by layer in the direction away from the support body 10 (that is, the true porosity of the first sub-functional layer 21, the second sub-functional layer 22, the third sub-functional layer 23... decreases in sequence).

[0045] Compared with the prior art, the inkjet printing consumables have at least the following advantages: on the one hand, by decreasing the true porosity of the multi-layer sub-functional layers in the direction away from the support body in sequence, the mechanical strength in the functional layer forms a "pyramid" structure, providing a "pyramid" type structural support. When the coating is subjected to a certain external pressure, the mechanical support of the "pyramid" structure is more stable, thereby protecting the pore structure in the functional layer from deformation, so that the surface of the consumables remains original, the reflective ability does not change, and there will be no problems of "whitening", "bright spots" or "bright bands". As a result, the process of coating with a protective film in the later stage can be omitted, and coating-free coating can be achieved, which greatly saves production costs. On the other hand, in the composite functional layer, the innermost sub-functional layer in direct contact with the support body has the highest true porosity, which helps to improve The ink absorption capacity of the functional layer is improved, so that it can quickly absorb ink, which can not only improve printing efficiency but also will not reduce image density, so that the printed image has the advantages of high color density, bright colors, and good color reproduction, which can meet the image-level image requirements; at the same time, in the composite functional layer, the outermost sub-functional layer farthest from the support has the smallest true porosity, which can not only improve the scratch resistance of the consumables, but also help to improve the glossiness of the coating surface, so that the printed image has a better gloss texture; in addition, the composite functional layer structure with the true porosity decreasing layer by layer also makes the consumables have better ink absorption, which can avoid the problem of ink accumulation caused by poor ink penetration affecting the quality of the printed image, and at the same time, it can also have better adaptability to ink, and can adapt to dye ink and pigment ink at the same time.

[0046] Combine the following Figures 1-2 The inkjet printing consumables of the above embodiment of the present invention are described in detail.

[0047] According to an embodiment of the present invention, the true porosity of each sub-functional layer can be calculated according to the following formula:

[0048] Sub-functional layer true porosity = (sub-functional layer area × thickness - sub-functional layer true volume) / sub-functional layer area × thickness

[0049] The true volume of the sub-functional layer, i.e., the actual volume of the solid matter in the sub-functional layer excluding the internal voids, can be obtained by using a true density analyzer of the Quantachrome 1200e type in the United States, using high-purity helium gas. The true volume of each sub-functional layer can be measured by the true density meter, and the true porosity can be calculated by the above formula.

[0050] Support 10

[0051] According to an embodiment of the present invention, Figures 1-2It is understood that the composite functional layer 20 is provided on at least one surface of the support 10. It should be noted that the type of the support 10 in the present invention is not particularly limited, and those skilled in the art can flexibly select it according to actual needs. For example, the support 10 may include at least one selected from base paper, plastic-coated paper, polypropylene (PP), polyethylene terephthalate (PET), polyvinyl chloride (PVC), triacetate film (TAC), polyethylene (PE), polycarbonate (PC), polybutylene terephthalate (PNT). For example, according to a specific example of the present invention, the support 10 may be a PP film, a PET film, a PVC film, a TAC film, a PE film, a PC film or a PNT film, and preferably may include at least one selected from plastic-coated paper, PET, and PP. In addition, it should also be noted that the composite functional layer can be provided on one surface of the support 10 according to the different requirements of single-sided printing and double-sided printing (refer to Figure 1 understanding) or on the opposite surfaces (reference Figure 2 understand).

[0052] According to an embodiment of the present invention, the thickness of the support 10 can be 50 to 400 μm, for example, 80 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm or 350 μm, etc. The inventors found that if the thickness of the support is too small, the problem of broken pieces is easy to occur during the production process; if the thickness of the support is too large, the prepared printing consumables are too thick, which is easy to cause poor machine passing and paper jam during the printing process. In the present invention, by controlling the thickness of the support to be within the above range, the production stability and printing fluency of the support are taken into account. In addition, it should be noted that the surface of the support can also be pretreated before forming the functional layer to enhance the surface energy of the support, so that it forms a surface layer with stronger polarity, which can significantly improve the bonding strength between the support and the functional layer and the ink. Among them, there is no special restriction on the pretreatment method, and those skilled in the art can flexibly choose according to the actual situation, for example, corona treatment or plasma treatment can be selected.

[0053] Composite functional layer 20

[0054] According to an embodiment of the present invention, referring to Figure 1Or 2 understands that the composite functional layer 20 includes a first sub-functional layer 21, a second sub-functional layer 22, a third sub-functional layer 23, etc., which are arranged layer by layer in a direction away from the support 10. The coating slurry of each sub-functional layer can independently include inorganic particles, a binder and a solvent. The static surface tension of the coating slurry of each sub-functional layer can be independently 15 to 45 mN / m, for example, 20 mN / m, 25 mN / m, 30 mN / m, 35 mN / m or 40 mN / m, etc. The inventors found that if the surface tension of the coating slurry of any sub-functional layer is too high, it will affect its uniform spreading on the support or the coating sub-functional layer; if the surface tension of the coating slurry of any sub-functional layer is too low, it will affect the spreading of the coating slurry of another sub-functional layer coated thereon. Furthermore, according to some specific embodiments of the present invention, the static surface tension of the coating slurry of at least three sub-functional layers can decrease layer by layer, thereby ensuring that the coating slurry of the sub-functional layer can flow levelly on its spreading surface while ensuring the uniform spreading of the sub-functional layer slurry coated thereon.

[0055] According to an embodiment of the present invention, the binder in each sub-functional layer may independently include an aqueous binder and / or a non-aqueous binder, for example, only an aqueous binder may be included, and the solvent may independently include an organic solvent and / or water, and the organic solvent may preferably be a volatile organic solvent, wherein when the selected binder is an aqueous binder, the added solvent may be only water; when the selected binder is a non-aqueous binder, the solvent may be only an organic solvent. Among them, the binder and other slurry components are dissolved by the solvent to make the coating slurry have a certain fluidity, and water and volatile organic solvents can evaporate when the slurry is dried after coating, while providing a certain porosity. Further, in order to increase the volatilization rate of the solvent and reduce the production cost, an organic solvent with a boiling point of less than 200°C can be selected, and an organic solvent with a boiling point of 60°C to 160°C is more preferably used, so as to further increase the volatilization rate of the solvent during the drying process after the slurry is coated, improve production efficiency, and reduce production costs. According to some specific embodiments of the present invention, the organic solvent may include at least one selected from alcohol solvents (such as methanol, ethanol, propanol, isopropanol, etc.), ketone solvents (such as acetone, butanone, methyl ethyl ketone, etc.), ester solvents (such as ethyl formate, methyl acetate, ethyl acetate, isopropyl acetate, etc.), and amide solvents (such as N,N-dimethylformamide, N,N-dimethylacetamide, etc.), and preferably may include at least one selected from ethanol, propanol, isopropanol, acetone, and ethyl acetate, thereby improving the compatibility of the components in the coating slurry and controlling the true porosity of each sub-functional layer.

[0056] According to an embodiment of the present invention, the adhesive in each sub-functional layer can be independently a water-based adhesive, wherein the water-based adhesive may include a water-soluble resin and / or a water-soluble emulsion, for example, it may include at least one selected from polyvinyl alcohol resin, cellulose resin, polyvinyl pyrrolidone, starch, pullulan, gelatin, polyimide, polyurethane, polystyrene, polymethacrylate, polyacrylic acid, and polybismaleimide, and preferably may include at least one selected from polyvinyl alcohol, polyurethane emulsion, and polyacrylic acid emulsion. According to some specific embodiments of the present invention, when polyvinyl alcohol is included in the binder, the degree of polymerization of the polyvinyl alcohol may preferably be 1700-4000, and the degree of hydrolysis may preferably be 60%-99%. The inventors have found that if the degree of polymerization of the polyvinyl alcohol is too low, the ability to bond inorganic particles is poor, which will cause cracking problems. If the degree of polymerization of the polyvinyl alcohol is too high, the production cost will be increased and it will be technically difficult to achieve. If the hydrolysis degree of the polyvinyl alcohol is too low, the functional layer coating will be soft and prone to scratches. If the hydrolysis degree of the polyvinyl alcohol is too high, it is difficult to achieve with the existing technology. By preferably using the above-mentioned polyvinyl alcohol, it is more conducive to ensuring the stability of each functional layer.

[0057] According to an embodiment of the present invention, in the direction away from the support 10, the mass ratio of the inorganic particles to the binder in each sub-functional layer decreases layer by layer (e.g., Figure 1 For example, the mass ratio of inorganic particles to binder in the first sub-functional layer 21, the second sub-functional layer 22, and the third sub-functional layer 23 decreases layer by layer). The inventors found that the mass ratio of inorganic particles to binder significantly affects the true porosity of the functional layer. If the mass ratio of inorganic particles to binder is too small, more binder will block the gaps formed between the nanoparticles, so that the true porosity of the formed sub-functional layer is low, resulting in poor ink absorption performance; and if the mass ratio of inorganic particles to binder is too large, the true porosity of the formed sub-functional layer is too large, which will weaken the adhesion of the sub-functional layer and affect the bending resistance and scratch resistance of the coating. In the present invention, by controlling the mass ratio of inorganic particles to binder in each sub-functional layer to decrease layer by layer in the direction away from the support, it is more conducive to achieving the true porosity of each sub-functional layer to decrease layer by layer in the direction away from the support. On the one hand, it can ensure that the sub-functional layer has good ink absorption, and on the other hand, it can also improve the folding resistance and scratch resistance of the outermost sub-functional layer, and at the same time it is also beneficial to improve the glossiness of the outermost sub-functional layer.

[0058] According to an embodiment of the present invention, the particle size of the inorganic particles in each sub-functional layer can be independently 0.05 to 10 μm, for example, 0.1 μm, 0.5 μm, 1 μm, 3 μm, 5 μm or 8 μm, etc. The inventors found that if the diameter of the inorganic particles is too small, the ink absorption of the sub-functional layer will be affected, and if the diameter of the inorganic particles is too large, the glossiness of the sub-functional layer will be affected. The present invention can better balance the ink absorption speed and glossiness of the inkjet printing consumables by controlling the particle size of the inorganic particles within the above range.

[0059] According to an embodiment of the present invention, the inorganic particles in each sub-functional layer can independently include at least one selected from zinc oxide, silicon dioxide, silica sol, aluminum oxide, calcium carbonate, porcelain clay, and barium sulfate. Among them, aluminum oxide has a large porosity, a large specific surface area, and good dispersibility. When used as an inorganic particle in a functional layer, aluminum oxide in a state of fine particles with a positive charge can fix the dye of the ink and form an image layer, presenting an image with high color rendering and high water resistance. At the same time, due to its good ink absorption, it can achieve a high printing speed of the printer without reducing the image density; and the silicon dioxide particles have a small particle size, a large specific surface area, a high glossiness and good ink absorption performance, so the inorganic particles can preferably be aluminum oxide and / or silicon dioxide. Further, according to some specific embodiments of the present invention, in the direction away from the support 10, the inorganic particles in the outermost sub-functional layer can be silica sol and / or silicon dioxide powder. Silica has a smaller particle size and has better gloss, surface hardness and scratch resistance than alumina. Silica sol can be a dispersion of nano-scale silica in water or an organic solvent. The use of silica sol can avoid the problem of dust emission due to the light weight of silica powder, making the operation more convenient and the process more environmentally friendly. The particle size of silica sol and / or silica powder can be 50 to 200 nm, preferably spherical particles. The inventors found that if the particle size is too small, it will affect the ink absorption of the functional layer; if the particle size is too large, it will cause the gloss of the outermost sub-functional layer to decrease. Furthermore, the particle size of silica sol and / or silica powder can be preferably 50 to 100 nm, so that the gloss and ink absorption of the surface of the inkjet printing consumables can be better taken into account.

[0060] According to an embodiment of the present invention, in a direction away from the support 10, the thickness of each sub-functional layer may decrease layer by layer (e.g., Figure 1For example, the thicknesses of the first sub-functional layer 21, the second sub-functional layer 22, and the third sub-functional layer 23 decrease layer by layer). The innermost layer of the composite functional layer 20 is a sub-functional layer provided on at least one surface of the support 10. By making its thickness the largest among the sub-functional layers, sufficient ink absorption capacity can be obtained; at the same time, in the direction away from the support, by making the thickness of each sub-functional layer thinner in sequence, it is also beneficial for the solvent in the ink, such as water, to be smoothly precipitated into the innermost layer, that is, the ink is dried quickly, and the color density of the image is improved; in addition, the use of this setting is also beneficial to achieve an increase in reflection effect from an optical angle and achieve better glossiness.

[0061] According to an embodiment of the present invention, the coating slurry of each sub-functional layer may also independently include at least one selected from a dispersant, a leveling agent and a cross-linking agent. Among them, the addition of a dispersant can improve the uniformity of the dispersion of the inorganic particles. There is no particular restriction on the type of dispersant in the present invention. Those skilled in the art can flexibly select it according to actual conditions. For example, it may include at least one selected from hydrochloric acid, nitric acid, boric acid, sulfuric acid, carbonic acid, phosphoric acid, citric acid, malic acid, tartaric acid, acetic acid, succinic acid, oxalic acid, sulfonic acid, lactic acid, formic acid, acetic acid, and propionic acid. By adding the above dispersant, the uniformity of the dispersion of the inorganic particles can be improved; there is no particular restriction on the selection of the leveling agent in the present invention. Those skilled in the art can flexibly select it according to actual conditions. For example, it may include at least one selected from acetylene leveling agents, fluorine leveling agents, silicone leveling agents, polyether-modified silicone leveling agents, and poly At least one of a siloxane leveling agent, an ether-modified polysiloxane leveling agent, and a polyoxyethylene ether active agent. By adding the above-mentioned leveling agent, the static surface tension of the coating slurry of each sub-functional layer can be regulated, which is beneficial to ensure that each layer of coating slurry is normally spread on the support or the sub-functional layer to avoid coating defects. In addition, there is no special restriction on the type of cross-linking agent in the present invention. Those skilled in the art can flexibly select it according to actual conditions. For example, it can include at least one selected from formaldehyde, glyoxal, boric acid, borax, polyisocyanate, and aziridine. By adding the above-mentioned cross-linking agent, it can interact with the adhesive to further improve its adhesion, water resistance and scratch resistance while ensuring that the sub-coating has good ink absorption.

[0062] According to an embodiment of the present invention, in the direction away from the support 10, the outermost sub-functional layer may further include a compound having a cationic group. It should be noted that when the inorganic filler in the outermost sub-functional layer is selected from silica sol and / or silica powder, silica is naturally negatively charged, and the inorganic particles in the outermost sub-functional layer can be modified by using a compound having a cationic group. When the anionic dye contacts the compound having a cationic group, a water-insoluble complex is generated, thereby fixing the ink to prevent the migration and diffusion of the ink, thereby greatly improving the color stability performance of the inkjet printing consumables (color stability performance refers to the color density change and color migration phenomenon that will occur after a period of time after printing is completed). Among them, the specific types of compounds with cationic groups are not particularly limited, and those skilled in the art can flexibly select them according to actual needs. For example, it can be at least one selected from polypropyleneamine, diethylenetriamine, dipropylenetriamine, triethylenetetramine, cationized polyvinyl alcohol, cationic starch, polyethyleneimine, allylamine, diallyl alkyl polymer, triethylbenzylammonium chloride, trimethylhexadecylammonium hydroxide, dodecyldimethylbenzylammonium bromide, aluminum nitrate, and aluminum chloride. The inventors have found that by selecting the above-mentioned types of compounds, the outermost sub-functional layer can have excellent color stability. Further, according to some specific embodiments of the present invention, the added amount of the compound having a cationic group can be 5 to 80 wt% of the mass of the inorganic particles in the sub-functional layer, for example, it can be 10 wt%, 15 wt%, 20 wt%, 30 wt%, 50 wt% or 70 wt%, etc. The inventors have found that if the amount of the cationic compound is too small, the effect of improving the ink fixation is poor, and if the amount of the cationic compound is too much, it is easy to cause the problem of ink accumulation. The present invention controls the amount of the compound having a cationic group to be within the above-mentioned range, thereby ensuring the stable ink absorption and ink fixation of the sub-functional layer while improving its color stability.

[0063] According to an embodiment of the present invention, Figure 1 Or 2 understands that the composite functional layer 20 may only include the first sub-functional layer 21, the second sub-functional layer 22 and the third sub-functional layer 23 arranged layer by layer in a direction away from the support, that is, the first sub-functional layer 21 is arranged on one surface of the support; the second sub-functional layer 22 is arranged on the side of the first sub-functional layer 21 away from the support 10; the third sub-functional layer 23 is arranged on the side of the second sub-functional layer 22 away from the support 10. To facilitate understanding of the inkjet printing consumables of the above embodiment of the present invention, the following is a detailed description of the inkjet printing consumables by taking the structure in which the composite functional layer 20 is composed of only three sub-functional layers 21, 22, 23 as an example:

[0064] True porosity of the first sub-functional layer 21, the second sub-functional layer 22, and the third sub-functional layer 23

[0065] According to a specific embodiment of the present invention, the true porosity of the first sub-functional layer 21, the second sub-functional layer 22, and the third sub-functional layer 23 decreases in sequence. Specifically, the true porosity of the first sub-functional layer 21 can be 40-80%, for example, 45%, 50%, 55%, 60% or 70%, etc.; the true porosity of the second sub-functional layer 22 can be 20-40%, for example, 25%, 28%, 30%, 35% or 38%, etc.; the true porosity of the third sub-functional layer 23 can be 2-20%, for example, 5%, 8%, 10%, 15% or 18%, etc. The inventor found that if the true porosity of the first sub-functional layer is greater than 80%, it is difficult to significantly improve the overall scratch resistance of the composite functional layer. If it is less than 40%, it is easy to cause insufficient ink absorption of the first sub-functional layer, and the problem of ink accumulation is easy to occur after printing; if the porosity of the second sub-functional layer is greater than 40%, it is also difficult to significantly improve the overall scratch resistance of the composite functional layer. If it is less than 30%, it is easy to affect the ink absorption and overall ink absorption of the functional layer, and the problem of ink accumulation is also easy to occur after printing; if the porosity of the third sub-functional layer is greater than 20%, it is difficult to improve the scratch resistance of the outer surface of the functional layer. If it is less than 2%, it is easy to cause the ink to not quickly penetrate into the second sub-functional layer and the third sub-functional layer after printing, thereby causing problems such as ink accumulation, slow ink drying, and even ink flow. The present application controls the true porosity of each sub-functional layer within the above range, and can improve the scratch resistance of the surface of the inkjet printing consumables while ensuring the ink absorption of the inkjet printing consumables.

[0066] The thickness of the first sub-functional layer 21, the second sub-functional layer 22, and the third sub-functional layer 23

[0067] According to a specific embodiment of the present invention, the thicknesses of the first sub-functional layer 21, the second sub-functional layer 22, and the third sub-functional layer 23 may decrease layer by layer. Furthermore, the thickness of the first sub-functional layer 21 may be 20 to 40 μm, for example, 22 μm, 25 μm, 30 μm, 35 μm or 38 μm, etc.; the thickness of the second sub-functional layer 22 may be 10 to 20 μm, for example, 12 μm, 13 μm, 15 μm or 18 μm, etc.; the thickness of the third sub-functional layer 23 may be 0.1 to 10 μm, for example, 0.3 μm, 0.5 μm, 1 μm, 3 μm, 5 μm or 8 μm, etc., thereby enabling the inkjet printing consumables to have a higher ink absorption capacity and better ink absorption, which is beneficial for the ink to penetrate and precipitate smoothly into the first sub-functional layer, thereby improving the color rendering of the image, and at the same time, it is beneficial to obtain better gloss on the basis of satisfying optical principles.

[0068] Selection of Inorganic Particles for the First Sub-Functional Layer 21, the Second Sub-Functional Layer 22, and the Third Sub-Functional Layer 23

[0069] According to a specific embodiment of the present invention, the inorganic particles in the first sub-functional layer 21 may be aluminum oxide and / or silicon dioxide; the inorganic particles in the second sub-functional layer 22 may be aluminum oxide and / or silicon dioxide; the inorganic particles in the third sub-functional layer 23 may be silica sol and / or silicon dioxide, wherein the particle size of the silica sol and / or silicon dioxide may be 50 to 200 nm. The reasons for selecting the above inorganic particles have been described in detail in the previous section, and will not be repeated here. In general, the selection of the above inorganic particles is conducive to improving the ink absorption and glossiness of the consumables.

[0070] Coating slurry of the first sub-functional layer 21, the second sub-functional layer 22, and the third sub-functional layer 23

[0071] According to a specific embodiment of the present invention, the coating slurry of the first sub-functional layer 21 may include: 15 to 30 parts by weight of inorganic particles, 0.3 to 3 parts by weight of dispersant, 1 to 2 parts by weight of aqueous adhesive, 0.5 to 1 part by weight of leveling agent, 10 to 20 parts by weight of organic solvent, 0.03 to 0.3 parts by weight of cross-linking agent, and 41 to 73.17 parts by weight of water. Among them, the inventors found that if the amount of inorganic particles is less than 15 parts by weight, it is easy to cause poor ink absorption; if the amount of inorganic particles is higher than 30 parts by weight, it is easy to cause cracks in the first sub-functional layer, and even powder loss; if the amount of dispersant is less than 0.3 parts by weight, the dispersion effect of inorganic particles is not good, affecting the glossiness of the sub-functional layer; if the amount of dispersant is higher than 3 parts by weight, the inorganic particles are too fine after dispersion, affecting the ink absorption of the first sub-functional layer; if the amount of aqueous adhesive is less than 1 part by weight, the sub-functional layer is prone to cracks; if the aqueous adhesive is If the amount of adhesive exceeds 2 parts by weight, it is easy to cause the vacuum rate of the first sub-functional layer to be low, the ink absorption is poor, and even the problem of ink accumulation may occur; if the amount of organic solvent is less than 10 parts by weight, it is easy to make the vacuum rate of the first sub-functional layer low, resulting in poor ink absorption of the first sub-functional layer. If the amount of organic solvent is higher than 20 parts by weight, it will affect the spreading of the sub-functional layer coating slurry on the support; if the amount of cross-linking agent is less than 0.03 parts by weight, the waterproof effect of the first sub-functional layer is poor. If the amount of cross-linking agent is higher than 0.3 parts by weight, it will affect the absorbency of ink. The present application can better take into account the ink absorption, glossiness and stability of the coating by controlling the composition and amount of the coating slurry in the first sub-functional layer. Furthermore, at least one selected from a tackifier, a pH adjuster, a lubricant, a defoamer, a waterproofing agent, a release agent, a fluorescent brightener, an ultraviolet absorber, an antioxidant, etc. can be flexibly added to the first sub-functional layer according to actual needs. There is no special restriction on the amount added. Those skilled in the art can flexibly select according to actual conditions as long as the relevant functional needs are met.

[0072] According to a specific embodiment of the present invention, the coating slurry of the second sub-functional layer 22 may include: 15 to 30 parts by weight of inorganic particles, 0.3 to 3 parts by weight of dispersant, 1.5 to 3 parts by weight of aqueous adhesive, 0.5 to 2 parts by weight of leveling agent, 5 to 15 parts by weight of organic solvent, 0.03 to 0.3 parts by weight of cross-linking agent, and 44 to 77.67 parts by weight of water. Among them, the inventor found that if the amount of aqueous binder is less than 1.5 parts by weight, it is easy to make the true porosity of the second sub-functional layer too high, so that the prepared inkjet printing consumables have poor scratch resistance; if the amount of aqueous adhesive exceeds 3 parts by weight, it is easy to cause the vacuum rate of the second sub-functional layer to be too low, the ink absorption is poor, and even cause ink accumulation. The reason why the amount of inorganic particles, dispersant, leveling agent, organic solvent, and cross-linking agent is controlled within the above range has been described in detail in the first sub-functional layer part, and will not be repeated here. The present application can better balance the ink absorption, glossiness and scratch resistance of the coating by controlling the composition and amount of the coating slurry in the second sub-functional layer within the above range. At the same time, at least one selected from a tackifier, a pH adjuster, a lubricant, a defoamer, a waterproofing agent, a release agent, a fluorescent brightener, an ultraviolet absorber, an antioxidant, etc. can be further added to the second sub-functional layer according to actual needs. There is no special restriction on the amount added, and those skilled in the art can flexibly select according to actual conditions, as long as the relevant functional needs are met.

[0073] According to a specific embodiment of the present invention, the coating slurry of the third sub-functional layer 23 may include: 1 to 10 parts by weight of inorganic particles, 0.01 to 0.1 parts by weight of dispersant, 0.5 to 2 parts by weight of aqueous adhesive, 2 to 0.5 parts by weight of leveling agent, 5 to 15 parts by weight of organic solvent, 0.1 to 2 parts by weight of cross-linking agent, and 65.9 to 93.64 parts by weight of water. Among them, the inventor found that if the amount of inorganic particles is less than 0.5 parts by weight, it is easy to cause the ink absorption of the third sub-functional layer to be poor, and if the amount of inorganic particles is higher than 10 parts by weight, it is easy to make the thickness of the third sub-functional layer too thick and affect the penetration of ink; if the amount of aqueous adhesive is less than 0.5 parts by weight, the true porosity of the third sub-functional layer is too high, and the prepared inkjet printing consumables have poor scratch resistance; if the amount of aqueous adhesive exceeds 2 parts by weight, the vacuum rate of the third sub-functional layer is too low, the ink absorption is poor, and even the problem of ink accumulation may be caused. The reason why the amount of dispersant, leveling agent, organic solvent and cross-linking agent is controlled within the above range has been described in detail in the first sub-functional layer part, and will not be repeated here. In general, the present application can better balance the ink absorption, high gloss and scratch resistance of the coating by controlling the composition and content of the coating slurry of the third sub-functional layer within the above range. In addition, a compound with a cationic group can be added to the third sub-functional layer, and the amount of the cationic group compound added can account for 5 to 80wt% of the amount of inorganic particles added to the third sub-functional layer. The selection of this dosage range has been described in detail in the previous part, and will not be repeated here. At the same time, the second sub-functional layer can also be further flexibly added with at least one selected from a tackifier, a pH adjuster, a lubricant, a defoamer, a waterproofing agent, a release agent, a fluorescent whitening agent, an ultraviolet absorber, an antioxidant, etc. according to actual needs. There is no special restriction on the amount added, and those skilled in the art can flexibly choose according to actual conditions, as long as the relevant functional needs are met.

[0074] In another aspect of the present invention, a method for preparing inkjet printing consumables is proposed. According to an embodiment of the present invention, the method comprises: forming at least three sub-functional layers on at least one surface of a support body in a direction away from the support body, and in the direction away from the support body, the true porosity of at least three sub-functional layers decreases layer by layer. The characteristics and effects described for the above-mentioned inkjet printing consumables are also applicable to the method for preparing inkjet printing consumables, which will not be described in detail here. In general, compared with the prior art, this method not only has a simple production process, but also can save the process of coating with a protective film in the later stage, realize the purpose of free coating, and greatly simplify the production process and reduce the production cost. In addition, the inkjet printing consumables prepared have good ink absorption and ink adaptability, high gloss on the coating surface, good scratch resistance, and will not cause "whitening", "bright spots" or "bright bands" during production and use.

[0075] According to an embodiment of the present invention, at least three sub-functional layers can be coated on a support at the same time by a coating device. The coating method is not particularly limited and can be any coating method known in the technical field to which the present invention belongs. Those skilled in the art can flexibly select according to actual needs. For example, screen printing, micro-gravure coating, slide extrusion coating, dip coating, spray coating, curtain coating or a combination of the above methods can be selected. Preferably, slide extrusion coating, dip coating, spray coating, curtain coating or a combination of the above methods can be selected.

[0076] According to an embodiment of the present invention, a drying process may be further included after coating is completed. The drying process may include cold air drying and hot air drying performed in sequence. There is no special requirement for the temperature of the hot air drying. Those skilled in the art may flexibly select it according to actual conditions. Preferably, the hot air temperature used in the hot air drying process may be increased gradually. By setting the hot air drying temperature to gradually increase, it is beneficial to further accelerate the reaction speed of the cross-linking agent and the binder, shorten the construction period, and improve production efficiency.

[0077] In another aspect of the present invention, a printing product is provided. According to an embodiment of the present invention, the printing product includes the above-mentioned inkjet printing consumables or the inkjet printing consumables prepared by the above-mentioned method. The characteristics and effects described for the above-mentioned inkjet printing consumables and the above-mentioned method for preparing inkjet printing consumables are also applicable to the printing product, and will not be repeated here. In general, compared with the prior art, the printing product not only has excellent scratch resistance, and will not produce problems of "whitening", "bright spots" or "bright bands" during production and use, but also has a higher glossiness, has the advantages of high color density, bright image colors, and good color reproduction, can meet the gloss texture and image-level image requirements comparable to photos, and has better overall quality.

[0078] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. If no specific techniques or conditions are specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used that do not specify the manufacturer are all conventional products that can be obtained commercially.

[0079] Example 1

[0080] (1) 30 g of aluminum oxide with a particle size of 0.1 μm, 0.3 g of nitric acid, 20 g of a 10 wt% polyvinyl alcohol solution (degree of polymerization: 1700, degree of hydrolysis: 99%), 0.5 g of an acetylene glycol leveling agent, 10 g of isopropanol, 0.3 g of boric acid, and 73.17 g of water were added into a container, dispersed at 10,000 rpm with high-speed stirring for 1 hour, and ultrasonically defoamed at 45° C. for 30 minutes to prepare a first sub-functional layer coating slurry.

[0081] (2) Add 15 g of aluminum oxide with a particle size of 0.2 μm, 3 g of citric acid, 15 g of 10 wt% polyvinyl alcohol solution (degree of polymerization: 1700, degree of hydrolysis: 99%), 1 g of silicone leveling agent, 5 g of isopropyl alcohol, 0.3 g of boric acid, and 44 g of water into a container, disperse the mixture at 10,000 rpm for 1 hour, and perform ultrasonic defoaming at 45°C for 30 minutes to prepare a second sub-functional layer coating slurry.

[0082] (3) 1 g of 200 nm silica, 0.01 g of nitric acid, 5 g of 10 wt% polyvinyl alcohol solution (polymerization degree of 3500, hydrolysis degree of 88%), 5 g of fluorine-containing leveling agent, 5 g of ethanol, 2 g of boric acid, and 73 g of water were added into a container. The mixture was dispersed at 10,000 rpm for 1 hour with high-speed stirring, and ultrasonically defoamed at 45° C. for 30 minutes to prepare a coating slurry for the third sub-functional layer.

[0083] The first sub-functional layer coating slurry, the second sub-functional layer coating slurry, and the third sub-functional layer coating slurry are simultaneously coated on a 200 g, 180 micron plastic-coated paper base using a slope extrusion device, and blow-dried at 10°C for 0.5 minute, at 20°C for 0.5 minute, at 40°C for 0.5 minute, and at 60°C for 2 minutes to obtain inkjet printing consumables with a first sub-functional layer, a second sub-functional layer, and a third sub-functional layer having a thickness of 30 microns, 10 microns, and 0.1 microns, respectively, in the direction away from the support.

[0084] Example 2

[0085] (1) 15 g of aluminum oxide with a particle size of 0.2 μm, 1 g of acetic acid, 10 g of cellulose (molecular weight 5000) with a concentration of 10 wt%, 1 g of a polyether-modified silicone leveling agent, 20 g of NN dimethylformamide, 0.3 g of boric acid, and 41 g of water were added into a container, dispersed at 10,000 rpm with high-speed stirring for 1 hour, and ultrasonically defoamed at 45° C. for 30 minutes to prepare a first sub-functional layer coating slurry.

[0086] (2) Add 30 g of aluminum oxide with a particle size of 0.1 μm, 1 g of hydrochloric acid, 30 g of 10 wt% polyvinyl alcohol solution (degree of polymerization: 1700, degree of hydrolysis: 99%), 1.5 g of ether-modified silicone leveling agent, 15 g of isopropyl alcohol, 0.2 g of boric acid, and 77.67 g of water into a container, disperse the mixture at 10,000 rpm for 1 hour with high-speed stirring, and perform ultrasonic defoaming at 45°C for 30 minutes to prepare a second sub-functional layer coating slurry.

[0087] (3) 1 g of 50 nm silica, 0.1 g of nitric acid, 20 g of 10 wt% polyvinyl alcohol solution (polymerization degree 3500, hydrolysis degree 99%), 2 g of ether-modified silicone leveling agent, 10 g of ethanol, 1 g of borax, and 65.9 g of water were added into a container. The mixture was dispersed at 10,000 rpm for 1 hour with high-speed stirring, and ultrasonically defoamed at 45° C. for 30 minutes to prepare a coating slurry for the third sub-functional layer.

[0088] The first sub-functional layer coating slurry, the second sub-functional layer coating slurry, and the third sub-functional layer coating slurry are simultaneously coated on a 350 g plastic-coated paper base using a slope extrusion device, and blow-dried at 10°C for 0.5 min, 20°C for 0.5 min, 60°C for 0.5 min, and 90°C for 2 min to obtain inkjet printing consumables with a first sub-functional layer, a second sub-functional layer, and a third sub-functional layer having thicknesses of 20 μm, 20 μm, and 5 μm, respectively, in the direction away from the support.

[0089] Example 3

[0090] (1) Add 20 g of aluminum oxide with a particle size of 10 μm, 3 g of acetic acid, 15 g of 10 wt% polyvinyl alcohol solution (degree of polymerization: 3500, degree of hydrolysis: 88%), 1 g of a polyether-modified silicone leveling agent, 15 g of isopropyl alcohol, 0.2 g of borax, and 59.67 g of water into a container, disperse the mixture at 10,000 rpm for 1 hour, and perform ultrasonic defoaming at 45°C for 30 minutes to prepare a first sub-functional layer coating slurry.

[0091] (2) Add 20 g of silica with a particle size of 0.5 μm, 0.3 g of nitric acid, 30 g of a 10 wt% polyvinyl alcohol solution (degree of polymerization: 1700, degree of hydrolysis: 99%), 1.5 g of a polyether-modified silicone leveling agent, 15 g of isopropyl alcohol, 0.03 g of boric acid, and 50.67 g of water into a container, disperse the mixture at 10,000 rpm for 1 hour, and perform ultrasonic defoaming at 45°C for 30 minutes to prepare a second sub-functional layer coating slurry.

[0092] (3) 17 g of silica sol with a concentration of 30 wt% and a particle size of 150 nm, 0.05 g of nitric acid, 12 g of a 10 wt% polyvinyl alcohol solution (with a degree of polymerization of 1700 and a degree of hydrolysis of 99%), 3 g of a polyether-modified silicone leveling agent, 10 g of ethanol, 0.1 g of borax, and 81.26 g of water were added to a container. The mixture was dispersed at 10,000 rpm for 1 hour with high-speed stirring, and ultrasonically defoamed at 45° C. for 30 minutes to prepare a coating slurry for the third sub-functional layer.

[0093] The first sub-functional layer coating slurry, the second sub-functional layer coating slurry, and the third sub-functional layer coating slurry are simultaneously coated on a 80-micron thick white PET using a slope extrusion device, and blow-dried at 50°C for 0.5 minute, 20°C for 0.5 minute, 40°C for 0.5 minute, and 80°C for 2 minutes to obtain inkjet printing consumables with a first sub-functional layer, a second sub-functional layer, and a third sub-functional layer having a thickness of 20 microns, 10 microns, and 10 microns, respectively, in the direction away from the support.

[0094] Example 4

[0095] The aluminum oxide in the first sub-functional layer and the second sub-functional layer in Example 1 is replaced by zinc oxide, the polyvinyl alcohol is replaced by gelatin, and the boric acid in the third sub-functional layer is replaced by formaldehyde. Other contents are the same as in Example 1.

[0096] Example 5

[0097] The aluminum oxide in the first sub-functional layer and the second sub-functional layer in Example 1 is replaced by calcium carbonate, the polyvinyl alcohol is replaced by polystyrene emulsion, and the boric acid in the third sub-functional layer is replaced by glyoxal. Other contents are the same as in Example 1.

[0098] Example 6

[0099] The alumina in the first sub-functional layer and the second sub-functional layer in Example 1 is replaced by china clay, polyvinyl alcohol is replaced by polyvinyl pyrrolidone, and the boric acid in the third sub-functional layer is replaced by polyisocyanate. Other contents are the same as in Example 1.

[0100] Example 7

[0101] The aluminum oxide in the first sub-functional layer and the second sub-functional layer in Example 1 is replaced by barium sulfate, the polyvinyl alcohol is replaced by starch, the boric acid in the third sub-functional layer is replaced by aziridine, and the other contents are the same as in Example 1.

[0102] Example 8

[0103] The polyvinyl alcohol in the third sub-functional layer in Example 2 is replaced by polymethacrylate emulsion, the polyether-modified silicone leveling agent is replaced by a fluorine-containing leveling agent, and the borax is replaced by aziridine. Other contents are the same as in Example 2.

[0104] Example 9

[0105] The polyvinyl alcohol in the third sub-functional layer in Example 2 is replaced by polyurethane emulsion, the polyether-modified silicone leveling agent is replaced by a fluorine-containing leveling agent, and the borax is replaced by aziridine. Other contents are the same as in Example 2.

[0106] Example 10

[0107] The alumina in the first sub-functional layer and the second sub-functional layer in Example 2 is replaced by china clay, polyvinyl alcohol is replaced by polyacrylic acid emulsion, isopropyl alcohol is replaced by propyl alcohol, and the other contents are the same as in Example 2.

[0108] Embodiment 11

[0109] The alumina in the first sub-functional layer and the second sub-functional layer in Example 2 is replaced by china clay, the polyvinyl alcohol is replaced by polystyrene emulsion, the isopropanol in the second sub-functional layer is replaced by ethyl acetate, and the other contents are the same as in Example 2.

[0110] Example 12

[0111] 0.05 g of polyacrylamine was added to the third sub-functional layer in Example 1, and the other contents were the same as in Example 1.

[0112] Embodiment 13

[0113] 0.8 g of aluminum nitrate was added to the third sub-functional layer in Example 1, and the other contents were the same as in Example 1.

[0114] Embodiment 14

[0115] 0.4 g of trimethylhexadecylammonium hydroxide was added to the third sub-functional layer in Example 1. Other contents were the same as in Example 1.

[0116] Comparative Example 1

[0117] Only the first sub-functional layer in Example 1 is retained, and the second sub-functional layer and the third sub-functional layer are not provided. The coating thickness is 40.1 microns, and other conditions are the same as in Example 1.

[0118] Comparative Example 2

[0119] Only the first sub-functional layer and the second sub-functional layer in Example 1 are retained, and the coating thicknesses are 30 μm and 10 μm respectively. The third sub-functional layer is not provided, and other conditions are the same as those in Example 1.

[0120] Comparative Example 3

[0121] Only the third sub-functional layer in Example 1 is retained, the coating thickness is 40 μm, the first sub-functional layer and the second sub-functional layer are not provided, and other conditions are the same as in Example 1.

[0122] Performance test: Under the same conditions, the above examples and comparative examples were characterized by the following test methods. The characterization results are shown in Table 1.

[0123] Test method:

[0124] 1) Surface tension of functional layer coating slurry

[0125] The surface tension of the functional layer coating slurry at a temperature of 40±0.5°C was tested using a DY-300 surface tension meter produced by Kyowa Inteface Science Co., Ltd. of Japan.

[0126] 2) Glossiness

[0127] The surface glossiness at an incident angle of 60° was measured using a gloss meter model PG-160.

[0128] 3) True porosity

[0129] In the embodiment, each functional layer coating slurry is coated on a PET support, heated and dried to obtain a coating with a coating thickness of 30 microns. The true volume of the coating is measured using a Quantachrome 1200e true density analyzer using high-purity helium gas. The true volume of each functional layer is measured using a true density meter, and the true porosity is calculated using the following formula: Functional layer porosity = (functional layer area × thickness - functional layer true volume) / functional layer area × thickness

[0130] 4) Ink adaptability

[0131] The ink absorption of Epson L805 (dye-based ink) and P10180 (pigment-based ink) was tested using the method in G / BTGB / T 21301-2007 inkjet printing paper. If both the dye and pigment inks have acceptable ink absorption, it is recorded as 2; if either the dye or pigment ink has acceptable ink absorption, it is recorded as 1; if both the dye and pigment inks have unacceptable ink absorption, it is recorded as 0.

[0132] 5) Scratch resistance

[0133] A homemade scratch test was conducted using a 1mm metal scraper tip. A steel ball counterweight was placed on the metal scraper tip, and the scraper tip was moved at a constant speed on the surface of the printed material coating. The weight when the scratch appeared was recorded, which was the anti-scratch weight.

[0134] 6) Whitening

[0135] Place the inkjet medium with the coating surface facing up on a flat glass, place a 40mm×300mm 220g plastic-coated paper strip with its back facing down on the coating surface, then place a 100g weight on the plastic-coated paper strip, pull the paper strip from one end of the inkjet medium to the other, and repeat 20 times. Use an Epson L805 inkjet printer to print a 100% black block, and then place a transparent film with 2mm×2mm squares on the black block, count the number of squares with and without "bright spots", calculate the percentage of the number of "bright spots", percentage = 0 is defined as level 0, 0 < percentage ≤ 5 is defined as level 1, 5 < percentage ≤ 10 is defined as level 2, and 10 < percentage is defined as level 3.

[0136] Table 1 Performance comparison of Examples 1 to 14 and Comparative Examples 1 to 3 and surface tension and true porosity of each sub-functional layer

[0137]

[0138] Results and discussion: Combining the data in the examples, comparative examples and Table 1, it can be seen that the inkjet printing consumables prepared in Examples 1 to 14 have good ink adaptability, high coating surface gloss, and good surface scratch resistance. There is no "whitening" phenomenon during use, and the overall performance is better. Specifically, compared with Example 1, the total coating thickness of Comparative Example 1 remains unchanged, but only the first sub-functional layer is retained, and its glossiness and scratch resistance are greatly reduced; compared with Example 1, the coating thickness of Comparative Example 2 remains basically unchanged, and only the first sub-functional layer and the second sub-functional layer are retained. Although it can achieve a certain glossiness, the scratch resistance is significantly reduced, and whitening occurs at the same time; compared with Example 1, the coating thickness of Comparative Example 3 remains basically unchanged, and only the third sub-functional layer is retained. Although the glossiness is slightly improved, the scratch resistance and ink adaptability are significantly reduced, and whitening occurs at the same time. In summary, in the above embodiments of the present application, by providing at least three sub-functional layers and making the true porosity of each layer decrease layer by layer in the direction away from the support body, the inkjet printing consumables can simultaneously meet the requirements of high ink adaptability, high gloss, and excellent scratch resistance, and will not have problems such as "whitening", "bright spots" or "bright bands".

[0139] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0140] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. An inkjet printing consumable, characterized in that: include: Support body; A composite functional layer, the composite functional layer is arranged on at least one surface of the support, the composite functional layer includes three sub-functional layers, each of the sub-functional layers independently includes inorganic particles and a binder, the three sub-functional layers are arranged layer by layer in a direction away from the support, and in the direction away from the support, the true porosity of the three sub-functional layers decreases layer by layer; in the direction away from the support, the true porosity of the three sub-functional layers is: 40-80%, 20-40%, and 2-20% in sequence; In the direction away from the support, the mass ratio of the inorganic particles to the binder in the three functional sub-layers decreases layer by layer; The three sub-functional layers are formed by drying a coating slurry, the coating slurry of each sub-functional layer independently comprises inorganic particles, a binder and a solvent, and the static surface tension of the coating slurry of each sub-functional layer is independently 15-45 mN / m; In the direction away from the support, the static surface tension of the coating slurry of the three sub-functional layers decreases layer by layer; In a direction away from the support, the thickness of the three sub-functional layers decreases layer by layer.

2. The inkjet printing consumable according to claim 1, characterized in that: At least one of the following conditions is met: The support has a thickness of 50 to 400 μm; The inorganic particles in each sub-functional layer independently include at least one selected from zinc oxide, silicon dioxide, silica sol, aluminum oxide, calcium carbonate, china clay, and barium sulfate; The particle size of the inorganic particles in each sub-functional layer is independently 0.05-10 μm; The coating slurry of each sub-functional layer further independently comprises at least one selected from a dispersant, a leveling agent and a cross-linking agent; The adhesive in each of the sub-functional layers is independently a water-based adhesive; The solvent in each sub-functional layer independently comprises an organic solvent and / or water; In the direction away from the support, the outermost sub-functional layer further comprises a compound having a cationic group, and the added amount of the compound having a cationic group is 5 to 80 wt % of the mass of the inorganic particles in the sub-functional layer.

3. The inkjet printing consumable according to claim 2, characterized in that: At least one of the following conditions is met: The support includes at least one of base paper, plastic-coated paper, polypropylene, polyethylene terephthalate, polyvinyl chloride, triacetate film, polyethylene, polycarbonate, and polybutylene terephthalate; The aqueous adhesive comprises at least one selected from polyvinyl alcohol resin, cellulose resin, polyvinyl pyrrolidone, starch, pullulan, gelatin, polyimide, polyurethane, polystyrene, polymethacrylate, polyacrylic acid, and polybismaleimide; The boiling point of the organic solvent is not greater than 200°C; The organic solvent includes at least one selected from alcohol solvents, ketone solvents, ester solvents, and amide solvents; The dispersant includes at least one selected from hydrochloric acid, nitric acid, boric acid, sulfuric acid, carbonic acid, phosphoric acid, citric acid, malic acid, tartaric acid, acetic acid, succinic acid, oxalic acid, sulfonic acid, lactic acid, formic acid, acetic acid, and propionic acid; The leveling agent includes at least one selected from acetylene leveling agent, fluorine leveling agent, silicone leveling agent, polyether-modified silicone leveling agent, polysiloxane leveling agent, ether-modified polysiloxane leveling agent, and polyoxyethylene ether active agent; The cross-linking agent includes at least one selected from formaldehyde, glyoxal, boric acid, borax, polyisocyanate, and aziridine; The compound having a cationic group includes at least one selected from polypropyleneamine, diethylenetriamine, dipropylenetriamine, cationized polyvinyl alcohol in triethylenetetramine, cationic starch, polyethyleneimine, allylamine, diallyl alkyl polymer, triethylbenzylammonium chloride, trimethylhexadecylammonium hydroxide, dodecyldimethylbenzylammonium bromide, aluminum nitrate, and aluminum chloride.

4. The inkjet printing consumable according to claim 1 or 3, characterized in that: In the direction away from the support, the inorganic particles in the outermost sub-functional layer are silica sol and / or silica powder; and / or the particle size of the inorganic particles in the outermost sub-functional layer is 50~200nm.

5. The inkjet printing consumable according to claim 4, characterized in that: The thicknesses of the three sub-functional layers are 20-40 μm, 10-20 μm, and 0.1-10 μm, respectively.

6. The inkjet printing consumable according to claim 4, characterized in that: The three sub-functional layers are sequentially a first sub-functional layer, a second sub-functional layer and a third sub-functional layer in a direction away from the support, and the three sub-functional layers meet at least one of the following conditions: The inorganic particles in the first sub-functional layer are aluminum oxide and / or silicon dioxide; The inorganic particles in the second sub-functional layer are aluminum oxide and / or silicon dioxide; The inorganic particles in the third sub-functional layer are silica sol and / or silicon dioxide powder; The particle size of the inorganic particles in the third sub-functional layer is 50-200 nm; The coating slurry of the first sub-functional layer includes: 15-30 parts by weight of the inorganic particles, 0.3-3 parts by weight of a dispersant, 1-2 parts by weight of an aqueous adhesive, 0.5-1 parts by weight of a leveling agent, 10-20 parts by weight of an organic solvent, 0.03-0.3 parts by weight of a cross-linking agent, and 41-73.17 parts by weight of water; The coating slurry of the second sub-functional layer includes: 15-30 parts by weight of the inorganic particles, 0.3-3 parts by weight of a dispersant, 1.5-3 parts by weight of an aqueous adhesive, 0.5-2 parts by weight of a leveling agent, 5-15 parts by weight of an organic solvent, 0.03-0.3 parts by weight of a cross-linking agent, and 44-77.67 parts by weight of water; The coating slurry of the third sub-functional layer includes: 1 to 10 parts by weight of the inorganic particles, 0.01 to 0.1 parts by weight of a dispersant, 0.5 to 2 parts by weight of an aqueous adhesive, 0.5 to 2 parts by weight of a leveling agent, 5 to 15 parts by weight of an organic solvent, 0.1 to 2 parts by weight of a cross-linking agent, and 65.9 to 93.64 parts by weight of water.

7. A method for preparing the inkjet printing consumables according to any one of claims 1 to 6, characterized in that: include: Forming three sub-functional layers on at least one surface of a support body in a direction away from the support body, and in the direction away from the support body, the true porosity of the three sub-functional layers decreases layer by layer; Optionally, the three sub-functional layers are simultaneously coated using a slide extrusion coating device; Optionally, after the coating is completed, a drying process is further included, and the drying process includes cold air drying and hot air drying performed in sequence, and the hot air temperature gradient used in the hot air drying process increases.

8. A printed product, characterized in that: The invention relates to an inkjet printing consumable comprising the inkjet printing consumable according to any one of claims 1 to 6 or an inkjet printing consumable prepared by the method according to claim 7.

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