Digitally printed photocatalytic decal paper and preparation method thereof, decal photocatalytic ceramic product

Abstract

The present invention belongs to the technical field of ceramic decorative decals, and specifically relates to a digital inkjet photocatalytic decal and a preparation method thereof, and a decal photocatalytic ceramic product. The digital inkjet photocatalytic decal comprises, from bottom to top, a base paper, a water-soluble adhesive layer, an ink absorption layer, a photocatalytic ink layer, and a cover oil layer; the ink absorption layer is formed by coating an absorption slurry, and the absorption slurry contains a comonomer; the photocatalytic ink layer is formed by inkjet printing of a photocatalytic ink, and the photocatalytic ink contains a nano-photocatalytic material and an ultraviolet absorber, and the ultraviolet absorber is selected from at least one of phenyl ester compounds, benzoazole compounds, and coumarin compounds. The present invention modifies the photocatalytic functional ink so that the decal can block the degradation reaction of the ultraviolet catalytic photocatalytic material on the comonomer in the ink absorption layer and the organic resin in the cover oil layer during storage, thereby effectively solving the problem of decreased photocatalytic performance of the decal and pattern quality.

Description

Technical Field

[0001] The invention belongs to the technical field of ceramic decorative decals, and in particular relates to a digitally printed photocatalytic decal and a preparation method thereof, and a decal photocatalytic ceramic product. Background Art

[0002] Photocatalysis, also known as photocatalyst, is a kind of photocatalysis that converts light energy into the energy required for chemical reactions under the irradiation of light to produce catalytic effects, so that the surrounding air and water molecules are stimulated into free photocatalysts with strong oxidizing power, which can oxidize and destroy the cell membrane and cell wall of bacteria, playing a role in sterilization. In addition, photocatalysis can also catalytically degrade organic matter and reduce the nutritional source of bacteria, thereby inhibiting the growth of bacteria.

[0003] Photocatalytic ceramic products are ceramic products with photocatalytic functions. At present, the preparation method is generally to first perform high-temperature modification on nano-titanium dioxide, then use traditional glazing or spraying technology for production and processing, and finally sinter at high temperature. However, during the high-temperature sintering process, nano-titanium dioxide will transform from the titanium anatase crystal phase to the rutile crystal phase, thereby reducing its photocatalytic performance. At the same time, when nano-titanium dioxide is coated on the surface of ceramics for sintering, the uneven thickness of titanium dioxide may cause iridescence on the surface of the product (light interference caused by different refractive indices), which seriously affects the surface quality of the product.

[0004] Ceramic decals refer to ceramic decals that are printed on the surface of ceramics (or ceramic blanks). Ceramic decals generally only need to be baked at a relatively low temperature to adhere to the ceramic surface. Therefore, if photocatalytic digital ink is inkjet printed on ceramic decals, high-temperature firing can be avoided to reduce the denaturation of photocatalytic materials at high temperatures. However, if ordinary photocatalytic ceramic ink is directly coated on decals, since decals will inevitably be exposed to natural light during storage, especially ultraviolet light, the electrons on the surface of the photocatalytic material will be excited into the conduction band to generate electron-hole pairs. Since electron holes have strong oxidizing properties, this strong oxidizing property will cause the decal structure layer in contact with them to undergo oxidation reactions and degrade, resulting in a decrease in performance or even disappearance, which in turn affects the quality of the decals. At the same time, due to the destruction of the decal structure, iridescence will also occur on its surface. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention proposes a digital inkjet photocatalytic decal and a preparation method thereof, and a decal photocatalytic ceramic product. The digital inkjet photocatalytic decal modifies the photocatalytic functional ink so that during the storage of the decal, the ultraviolet catalytic photocatalytic material can block the degradation reaction of the copolymer in the ink adsorption layer and the organic resin in the cover oil layer, and during the baking process, the modifier (ultraviolet absorber) will be burned away, and the photocatalytic performance of the decal is restored, thereby effectively avoiding the damage of the structural layer during the storage of the decal. At the same time, by setting a specific layer structure of the decal and selecting appropriate raw materials and proportions to interact with each other, the uniformity of the distribution of the photocatalytic material in the decal is solved to overcome the iridescence phenomenon.

[0006] In order to solve the above technical problems, the first aspect of the present invention provides a digitally printed photocatalytic flower paper, which comprises, from bottom to top, a base paper, a water-soluble glue layer, an ink adsorption layer, a photocatalytic ink layer and a cover oil layer; the photocatalytic ink layer is formed by inkjet printing of photocatalytic ink, and the photocatalytic ink contains nano-photocatalytic materials and ultraviolet absorbers, and the ultraviolet absorbers are selected from at least one of phenyl ester compounds, benzoazole compounds, and coumarin compounds.

[0007] Specifically, the digitally printed photocatalytic flower paper of the present invention is composed of base paper, a water-soluble adhesive layer, an ink absorption layer, a photocatalytic ink layer and a cover oil layer, wherein: the ink absorption layer is conducive to fixing and quickly absorbing the photocatalytic ink of the ink layer, and can isolate the photocatalytic ink layer from the water-soluble adhesive layer, preventing the uneven thickness distribution of the photocatalytic material in the ink layer due to diffusion or infiltration; the cover oil layer is used to fix and protect the photocatalytic ink layer; the water-soluble adhesive layer can be quickly separated from the base paper when the flower paper is water-transferred, and the water-soluble adhesive layer is also a second barrier to isolate the ink absorption layer from the base paper, which can prevent the infiltration of the photocatalytic ink, further ensure the uniformity of the thickness distribution of the photocatalytic material, and thus prevent the occurrence of the iridescence phenomenon.

[0008] The functional layer of the digitally printed photocatalytic decal of the present invention is a photocatalytic ink layer, which is formed by inkjet printing of photocatalytic ink, and generates a photocatalytic function through a photocatalytic material. When the photocatalytic material is acted upon by ultraviolet light, an electron-hole pair will be generated. Since the comonomer in the ink adsorption layer and the organic resin in the cover oil layer contain functional groups such as double bonds, ester bonds, and alcohols, for double bonds, the electron-hole pair will break the double bonds through a photooxidation reaction; for ester bonds, the electron-hole pair will break the ester bonds through an ester oxygenation reaction, and decompose the esters into aldehydes, acids, and other substances; for alcohols, the electron-hole pair will decompose the alcohols into ketones, aldehydes, and other substances through a photooxidation reaction, thereby destroying the structure of the ink adsorption layer and the cover oil layer, affecting the normal transfer of the decal; and after the transfer, due to the uneven thickness of the decal, an iridescence phenomenon will occur. The present invention adds an ultraviolet absorber, such as at least one of an ester compound, a benzoazole compound, and a coumarin compound, to the photocatalytic ink. These compounds all contain aromatic rings, allyl groups, and other conjugated systems or groups with good absorption performance, such as phenol, phenolic aldehyde, benzoyl formic acid, and benzoic acid, which have strong absorption of ultraviolet radiation in their molecular structures. When ultraviolet rays act on these compounds, they will absorb the energy of ultraviolet rays through the absorption of the conjugated structure or absorptive groups inside the molecules, and convert the light energy into heat energy or non-ultraviolet radiation, thereby protecting or stabilizing the photocatalytic material, blocking ultraviolet light to make the photocatalytic material generate electron-hole pairs, thereby avoiding degradation reactions with the ink adsorption layer and the cover layer, and protecting the structural performance of the decal. At the same time, the boiling point of the ultraviolet absorber is relatively low, and it will be burned away during the firing process of the decal in the later stage, so that the photocatalytic performance of the decal is restored, and it does not affect its photocatalytic performance during use.

[0009] Preferably, the photocatalytic material is selected from at least one of anatase titanium dioxide, zinc oxide, titanium nitride and carbon nitride.

[0010] Preferably, the phenyl ester compound is selected from at least one of p-hydroxybenzoic acid ester, p-hydroxystyrene ester, p-hydroxyphenylpyruvate ester, benzoic acid ester and p-aminobenzoic acid ester.

[0011] Preferably, the benzoazole compound is selected from at least one of benzotriazole, benzothiazole and benzopyrazole.

[0012] Preferably, the coumarin compound is selected from coumarin and / or phenoxycoumarin.

[0013] As a further improvement of the above solution, the mass ratio of the nano-photocatalytic material to the ultraviolet absorber is (2-25):1.

[0014] Specifically, by controlling the photocatalytic material and the ultraviolet absorber within a specific range, it can be ensured that the flower paper fully absorbs ultraviolet rays during the storage period and effectively blocks ultraviolet rays to protect the photocatalyst from photocatalysis, thereby ensuring the stability of the flower paper.

[0015] Preferably, the mass ratio of the nano-photocatalytic material to the ultraviolet absorber is (5-10):1.

[0016] As a further improvement of the above scheme, the photocatalytic ink further contains a photocatalytic accelerator, a quick-drying solvent, a dispersant, a low-temperature frit and a tracer; the raw material composition of the photocatalytic ink further includes, by weight:

[0017]

[0018] Specifically, the photocatalytic promoter enhances the catalytic performance of the photocatalytic material or adsorbs and disperses the photocatalyst to increase the speed and effect of the photocatalytic reaction, thereby improving the photocatalytic performance of the photocatalytic material; the quick-drying solvent refers to a solvent with a low boiling point and strong volatility. The selection of the quick-drying solvent can quickly evaporate the photocatalytic ink after high-speed printing, which is conducive to reducing the influence of the solvent on the uniformity of the distribution of the photocatalytic material; the low-temperature frit refers to a frit with a melting temperature below 900°C to meet the needs of paper baking. In addition, the photocatalytic ink of the present invention also contains a tracer, which is a colored pigment, mainly used to determine the effect of the transfer, so as to keep the thickness of the photocatalytic material consistent during the water transfer process, thereby avoiding the occurrence of iridescence. If there is a tracer left on the base paper after separation, it means that the immersion time is too long, the water-soluble glue is completely dissolved, and part of the ink adsorption layer is water-soluble; if irregular color blocks or color groups appear in the pattern layer after flattening, it also means that the transfer thickness of the photocatalytic material is uneven. The raw materials interact with each other under a specific ratio, and the uniformity of the thickness distribution of the photocatalytic material is improved under the premise of protecting the flower paper structure from being destroyed.

[0019] As a further improvement of the above solution, the photocatalytic promoter is selected from at least one of indium oxide, cerium oxide, neodymium oxide, nano-white carbon black, and nano-carbon black.

[0020] Specifically, the photocatalytic promoter can be a rare earth metal oxide, such as indium oxide, cerium oxide or neodymium oxide. These rare earth metal oxides have good redox properties and can act as electron acceptors or donors in the photocatalytic reaction, thereby enhancing the rate and effect of the photocatalytic reaction; it can also be nano-silica or nano-carbon black, which can effectively adsorb and disperse the catalyst and products in the photocatalytic reaction due to its high specific surface area and adsorption properties, reduce its aggregation and reaction hindrance during the reaction, thereby improving the rate and effect of the photocatalytic reaction.

[0021] Preferably, the quick-drying solvent is selected from at least one of ethylene glycol, dipropylene glycol methyl ether, propylene glycol methyl ether acetate, propylene glycol propyl ether, and n-propyl propionate.

[0022] Preferably, the dispersant is selected from at least one of ethylene glycol, acetone and glycerol;

[0023] As a further improvement of the above scheme, the ink absorption layer is formed by coating an absorption slurry, and the raw materials of the absorption slurry include, by weight:

[0024]

[0025] Specifically, the ink adsorption layer of the present invention is a coating with a certain viscosity prepared with a comonomer as the main raw material, which can form a strong adhesive force under the action of ink gravity alone, ensuring the adsorption and fixation of the ink adsorption layer to the photocatalytic ink layer. At the same time, an emulsifier and an initiator are added, wherein: the emulsifier can reduce the interfacial free energy of the photocatalytic ink to form a stable interfacial film, so that during the volatilization of the solvent in the photocatalytic ink, the ink droplets in Brownian motion are not easy to coalesce, and at the same time, the photocatalytic ink can be kept uniformly attached to the ink adsorption layer, avoiding cracks and iridescence caused by different ink thicknesses during the later baking process.

[0026] Preferably, the comonomer is selected from at least one of methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, styrene, acrylonitrile, vinyl acetate, vinylidene chloride, acrylic acid, acrylamide, hydroxymethyl acrylamide, hydroxyethyl methacrylate, ethylene glycol dimethacrylate, hydroxypropyl acrylate, and N-hydroxymethyl acrylamide.

[0027] Preferably, the emulsifier is selected from TX-10.

[0028] Preferably, the initiator is selected from at least one of persulfate, hydrogen peroxide and water-soluble azo initiator.

[0029] Preferably, the water is deionized water.

[0030] As a further improvement of the above scheme, the water-soluble glue layer is formed by coating a water-soluble glue, and the water-soluble glue includes at least one of gelatin, gum arabic, polyvinyl pyrrolidone, dextrin, and starch.

[0031] Preferably, the base paper is wood-free paper, which has good water absorption and will not shrink or wrinkle when exposed to water. Its thickness is 120-150g / m 2 .

[0032] The second aspect of the present invention provides a method for preparing a digitally printed photocatalytic decal, the method being used to prepare the digitally printed photocatalytic decal according to the first aspect of the present invention, comprising the following steps:

[0033] First, water-soluble glue and raw materials for preparing ink absorption layer (absorption slurry) are coated on base paper successively to form water-soluble glue layer and ink absorption layer; then photocatalytic ink is inkjet printed to form photocatalytic ink layer; then cover oil is sprayed to form cover oil layer; finally, drying is performed to obtain the digitally printed photocatalytic flower paper.

[0034] Preferably, the thickness of the water-soluble adhesive layer and the ink absorption layer are both 10-15 μm.

[0035] Preferably, the drying temperature is 75-85° C. and the drying time is 10-15 minutes.

[0036] Preferably, the cover oil layer has a thickness of 10-30 μm. A cover oil layer of a certain thickness can maintain a certain strength during the transfer process (especially when flattening) to avoid cracking.

[0037] The third aspect of the present invention provides a decal photocatalytic ceramic product, comprising a ceramic substrate and a photocatalytic functional layer, wherein the photocatalytic functional layer is formed by baking the digitally printed photocatalytic decal paper according to the first aspect of the present invention.

[0038] The fourth aspect of the present invention provides a method for preparing a decal photocatalytic ceramic product, the preparation method is used to prepare the decal photocatalytic ceramic product according to the third aspect of the present invention, comprising the following steps:

[0039] The digitally printed photocatalytic decal paper is soaked in water to separate the base paper; the separated digitally printed photocatalytic decal paper is then pasted on the surface of the ceramic base body, scraped flat and then baked to obtain the decal photocatalytic ceramic product.

[0040] Preferably, the baking temperature is 700-900° C. and the time is 4-8 hours. The cover oil layer will be burned off during the baking process, and will not affect the sintering of the photocatalytic ink layer.

[0041] Preferably, the soaking time is 3-6 minutes. The scraping refers to scraping away bubbles, wrinkles and water in the flower paper with a rubber scraper.

[0042] Compared with the prior art, the above technical solution of the present invention has at least the following technical effects or advantages:

[0043] (1) The photocatalytic ink layer of the digitally printed photocatalytic decal paper of the present invention is arranged between the ink absorption layer and the cover oil layer. In order to overcome the photocatalytic material in the ink absorption layer generating electron-hole pairs due to the action of ultraviolet light during storage, thereby degrading the ink absorption layer and the cover oil layer, the present invention adds a specific ultraviolet absorber, such as phenyl ester compounds, benzoazole compounds or coumarin compounds, to protect or stabilize the photocatalytic material and avoid the occurrence of iridescence. At the same time, the ultraviolet absorber will be burned away during the later baking process of the decal paper, and the photocatalytic performance of the decal paper can be restored, which does not affect its photocatalytic performance during use.

[0044] (2) The digitally printed photocatalytic decal paper of the present invention is composed of a base paper, a water-soluble adhesive layer, an ink absorption layer, a photocatalytic ink layer and a cover oil layer, wherein: the ink absorption layer is conducive to fixing and quickly absorbing the photocatalytic ink of the ink layer, and can isolate the photocatalytic ink layer from the water-soluble adhesive layer, thereby preventing the photocatalytic material in the ink layer from diffusing or seeping and causing uneven thickness distribution; the water-soluble adhesive layer can be quickly separated from the base paper when the decal paper is subjected to water transfer printing, and at the same time, the water-soluble adhesive layer is also a second barrier isolating the ink absorption layer from the base paper, thereby preventing the photocatalytic ink from seeping and further ensuring the uniformity of the thickness distribution of the photocatalytic material, thereby further preventing the occurrence of the iridescence phenomenon. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a physical picture of the decal photocatalytic ceramic prepared in Example 1;

[0046] Figure 2 This is a physical picture of the decal photocatalytic glass prepared in Example 2;

[0047] Figure 3 This is a physical picture of the decal photocatalytic ceramic prepared in Comparative Example 1. DETAILED DESCRIPTION

[0048] The present invention is described in detail below in conjunction with the examples, so that the technical personnel of the relevant technical field can understand the present invention. It is necessary to point out here that the examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. The non-essential improvements and adjustments made to the present invention by the skilled person in the relevant field according to the above invention content should still belong to the scope of protection of the present invention. At the same time, the raw materials mentioned below that are not described in detail are all commercially available products; the process steps or preparation methods that are not mentioned in detail are all process steps or preparation methods known to those skilled in the art.

[0049] The base paper used in the following examples and comparative examples is all woodfree paper, and the cover oil is KA3422 cover oil specially made for flower paper.

[0050] Example 1

[0051] A digital printing photocatalytic flower paper is composed of base paper, a water-soluble glue layer, an ink adsorption layer, a photocatalytic ink layer and a cover oil layer from bottom to top, wherein the water-soluble glue is gelatin.

[0052] The photocatalytic ink layer is formed by inkjet printing of photocatalytic ink. The raw materials of the photocatalytic ink are composed of the following by weight: 10 parts of nano-anatase titanium dioxide, 5 parts of indium oxide, 2 parts of parabens, 40 parts of ethylene glycol, 10 parts of acetone, 5 parts of borate low-temperature frit (melting temperature is 800°C), and 0.1 parts of indigo.

[0053] The ink adsorption layer is formed by coating the adsorption slurry. The raw materials of the adsorption slurry are composed of 30 parts of methyl acrylate, 20 parts of methyl methacrylate, 2 parts of acrylic acid, 3 parts of emulsifier TX-10, 0.7 parts of ammonium persulfate and 55 parts of deionized water in parts by weight.

[0054] The preparation method of the adsorption slurry comprises the following steps: first, according to the mass ratio of the present embodiment, 0.6 parts of emulsifier TX-10 is dissolved in deionized water and heated to 70°C; then, 4 parts of methyl acrylate, 6 parts of methyl methacrylate, 0.4 parts of acrylic acid and 0.14 parts of ammonium persulfate are added dropwise for 70 minutes, and the temperature is raised to 85°C after the addition is completed; and the remaining methyl acrylate, methyl methacrylate, acrylic acid and ammonium persulfate are added dropwise for 3 hours, and the temperature is kept for 30 minutes after the addition is completed. After cooling, the pH value is adjusted to be neutral to obtain the adsorption slurry.

[0055] A method for preparing digital printing photocatalytic flower paper comprises the following steps:

[0056] (1) dissolving gelatin in water (the mass volume ratio of gelatin to water is 1:3 g / mL), stirring continuously to form a uniform colloidal liquid, and coating it on the base paper with a coating rod, with a coating thickness of 10 μm, to form a water-soluble glue layer;

[0057] (2) coating the prepared adsorption slurry on the water-soluble adhesive layer by a coating rod, with a coating thickness of 10 μm, to form an ink adsorption layer;

[0058] (3) inkjet printing the photocatalytic ink on the ink adsorption layer to form a photocatalytic ink layer;

[0059] (4) After the ink layer is dry, cover oil is sprayed on the surface with a spray thickness of 20 μm and dried at 75° C. for 10 minutes to obtain the digitally printed photocatalytic decal paper of this embodiment.

[0060] A decal photocatalytic ceramic product comprises a ceramic substrate and a photocatalytic functional layer, wherein the photocatalytic functional layer is formed by baking the digitally printed photocatalytic decal paper prepared in this embodiment.

[0061] A method for preparing a decal photocatalytic ceramic product comprises the following steps:

[0062] The digitally printed photocatalytic decal paper was soaked in water for 5 minutes to separate the base paper; the separated digitally printed photocatalytic decal paper was then pasted on the surface of the ceramic substrate, and after being scraped flat, it was baked at 850°C for 4 hours to obtain the decal photocatalytic ceramic of this embodiment.

[0063] Figure 1 This is a photocatalytic ceramic decal prepared in Example 1. Figure 1 It can be seen that the structure of the flower paper is intact, the pattern is clear, and there is no iridescence phenomenon.

[0064] Example 2

[0065] A digital printing photocatalytic flower paper is composed of base paper, a water-soluble glue layer, an ink adsorption layer, a photocatalytic ink layer and a cover oil layer from bottom to top, wherein: the water-soluble glue is dextrin.

[0066] The photocatalytic ink layer is formed by inkjet printing of photocatalytic ink. The raw materials of the photocatalytic ink are composed of 18 parts of nano zinc oxide, 3 parts of cerium oxide, 3 parts of benzotriazole, 45 parts of propylene glycol propyl ether, 15 parts of ethylene glycol, 6 parts of phosphate low-temperature frit (melting temperature is 750°C), and 0.8 parts of methyl orange.

[0067] The ink adsorption layer is formed by coating the adsorption slurry. The raw materials of the adsorption slurry are composed of 35 parts of butyl acrylate, 15 parts of ethylene glycol dimethacrylate, 5 parts of emulsifier TX-10, 0.8 parts of ammonium persulfate and 60 parts of deionized water in parts by weight.

[0068] The preparation method of the adsorption slurry comprises the following steps: first, according to the mass ratio of the present embodiment, 1 part of the emulsifier TX-10 is dissolved in deionized water and heated to 70°C; then, 7 parts of butyl acrylate, 3 parts of ethylene glycol dimethacrylate and 0.16 parts of ammonium persulfate are added dropwise for 70 minutes, and the temperature is raised to 85°C after the addition is completed; then, the remaining methyl acrylate, methyl methacrylate, acrylic acid and ammonium persulfate are added dropwise for 3 hours, and the temperature is kept for 30 minutes after the addition is completed. After cooling, the pH value is adjusted to be neutral to obtain the adsorption slurry.

[0069] A method for preparing digital printing photocatalytic flower paper comprises the following steps:

[0070] (1) Dissolve dextrin in water (the mass volume ratio of dextrin to water is 1:4 g / mL), continue stirring to form a uniform colloidal liquid, and apply it on the base paper with a coating rod to a coating thickness of 12 μm to form a water-soluble adhesive layer;

[0071] (2) coating the prepared adsorption slurry on the water-soluble adhesive layer by a coating rod, with a coating thickness of 12 μm, to form an ink adsorption layer;

[0072] (3) inkjet printing the photocatalytic ink on the ink adsorption layer to form a photocatalytic ink layer;

[0073] (4) After the ink layer is dried, cover oil is sprayed on the surface with a spraying thickness of 25 μm, and dried at 80° C. for 15 minutes to obtain the digitally printed photocatalytic decal paper of this embodiment.

[0074] A decal photocatalytic ceramic product comprises a ceramic substrate and a photocatalytic functional layer, wherein the photocatalytic functional layer is formed by baking the digitally printed photocatalytic decal paper prepared in this embodiment.

[0075] A method for preparing a decal photocatalytic ceramic product comprises the following steps:

[0076] The digitally printed photocatalytic decal paper was soaked in water for 5 minutes to separate the base paper; the separated digitally printed photocatalytic decal paper was then pasted on the surface of the ceramic substrate, and after being scraped flat, it was baked at 800° C. for 5 hours to obtain the decal photocatalytic glass of this embodiment.

[0077] Figure 2 This is a photocatalytic ceramic decal prepared in Example 2. Figure 2 It can be seen that the flower paper has a good structure, a uniform metallic luster, and no iridescence.

[0078] Example 3

[0079] A digital printing photocatalytic flower paper is composed of base paper, a water-soluble glue layer, an ink absorption layer, a photocatalytic ink layer and a cover oil layer from bottom to top, wherein the water-soluble glue is gum arabic.

[0080] The photocatalytic ink layer is formed by inkjet printing of photocatalytic ink. The raw materials of the photocatalytic ink are composed of 25 parts of nano titanium nitride, 2 parts of nano white carbon black, 4 parts of coumarin, 50 parts of dipropylene glycol methyl ether, 20 parts of glycerol, 8 parts of silicate low-temperature frit (melting temperature is 850°C), and 1.5 parts of phthalocyanine blue.

[0081] The ink adsorption layer is formed by coating the adsorption slurry. The raw materials of the adsorption slurry are composed of 35 parts of ethyl acrylate, 20 parts of styrene, 4 parts of emulsifier TX-10, 0.8 parts of ammonium persulfate and 55 parts of deionized water in parts by weight.

[0082] The preparation method of the adsorption slurry comprises the following steps: first, according to the mass ratio of the present embodiment, 1 part of the emulsifier TX-10 is dissolved in deionized water and heated to 70°C; then, 7 parts of ethyl acrylate, 4 parts of styrene and 0.16 parts of ammonium persulfate are added dropwise for 70 minutes, and the temperature is raised to 85°C after the addition is completed; then, the remaining methyl acrylate, methyl methacrylate, acrylic acid and ammonium persulfate are added dropwise for 3 hours, and the temperature is kept for 30 minutes after the addition is completed. After cooling, the pH value is adjusted to be neutral to obtain the adsorption slurry.

[0083] A method for preparing digital printing photocatalytic flower paper comprises the following steps:

[0084] (1) dissolving gum arabic in water (the mass volume ratio of gum arabic to water is 1:3 g / mL), stirring continuously to form a uniform colloidal liquid, and coating the liquid on the base paper with a coating rod to a coating thickness of 15 μm to form a water-soluble glue layer;

[0085] (2) coating the prepared adsorption slurry on the water-soluble adhesive layer by a coating rod, with a coating thickness of 15 μm, to form an ink adsorption layer;

[0086] (3) inkjet printing the photocatalytic ink on the ink adsorption layer to form a photocatalytic ink layer;

[0087] (4) After the ink layer is dried, cover oil is sprayed on the surface with a spraying thickness of 30 μm, and dried at 85° C. for 15 minutes to obtain the digitally printed photocatalytic decal paper of this embodiment.

[0088] A decal photocatalytic ceramic product comprises a ceramic substrate and a photocatalytic functional layer, wherein the photocatalytic functional layer is formed by baking the digitally printed photocatalytic decal paper prepared in this embodiment.

[0089] A method for preparing a decal photocatalytic ceramic product comprises the following steps:

[0090] The digitally printed photocatalytic decal paper was soaked in water for 5 minutes to separate the base paper; the separated digitally printed photocatalytic decal paper was then pasted on the surface of the ceramic substrate, and after being scraped flat, it was baked at 900°C for 6 hours to obtain the decal photocatalytic ceramic product of this embodiment.

[0091] Example 4

[0092] The difference between Example 4 and Example 1 is that the photocatalytic ink of Example 4 does not contain photocatalytic promoter indium oxide, and the raw material composition of the photocatalytic ink of Example 4 is as follows, by weight: 10 parts of nano-anatase titanium dioxide, 2 parts of paraben, 40 parts of ethylene glycol, 10 parts of acetone, 5 parts of borate low-temperature melt (melting temperature is 800°C), and 0.1 parts of indigo.

[0093] Example 5

[0094] The difference between Example 5 and Example 1 is that the photocatalytic ink of Example 4 does not contain tracer indigo, and the raw material composition of the photocatalytic ink of Example 5 is as follows, by weight: 10 parts of nano-anatase titanium dioxide, 5 parts of indium oxide, 2 parts of parabens, 40 parts of ethylene glycol, 10 parts of acetone, and 5 parts of borate low-temperature melt (melting temperature is 800°C).

[0095] Comparative Example 1

[0096] The difference between Comparative Example 1 and Example 1 is that the raw material composition of the photocatalytic ink of Comparative Example 1 does not contain the ultraviolet absorber paraben, and the raw material components of the photocatalytic ink of Comparative Example 1 are calculated by weight as follows: 10 parts of nano-anatase titanium dioxide, 5 parts of indium oxide, 40 parts of ethylene glycol, 10 parts of acetone, 5 parts of borate low-temperature frit (melting temperature is 800°C), and 0.1 parts of indigo.

[0097] Figure 3 This is a photocatalytic ceramic decal prepared in Comparative Example 1. Figure 3 It can be seen that the flower paper is missing flowers and cracked, and there is iridescence.

[0098] Comparative Example 2

[0099] The difference between Comparative Example 2 and Example 2 is that the raw material composition of the photocatalytic ink of Comparative Example 2 does not contain the ultraviolet absorber parahydroxybenzoate, and the raw material components of the photocatalytic ink of Comparative Example 2 are as follows, by weight: 15 parts of nano zinc oxide, 3 parts of cerium oxide, 3 parts of benzotriazole, 45 parts of propylene glycol propyl ether, 15 parts of ethylene glycol, 6 parts of phosphate low-temperature melt (melting temperature is 750°C), and 0.8 parts of methyl orange.

[0100] Comparative Example 3

[0101] The difference between Comparative Example 3 and Example 1 is that the layer structure of the ceramic inkjet printed flower paper of Comparative Example 3 does not include an ink adsorption layer, and the ceramic inkjet printed flower paper of Comparative Example 3 comprises, from bottom to top, a base paper, a water-soluble glue layer, a photocatalytic ink layer and a cover oil layer.

[0102] Performance Testing

[0103] According to the standard JC / T897-2014 "Antibacterial Performance of Antibacterial Ceramic Products", the antibacterial rate of the decal photocatalytic ceramic products prepared in each embodiment and the comparative example was tested, and the appearance quality and pattern of the digitally printed photocatalytic flower paper and decal photocatalytic ceramic products prepared in each embodiment and the comparative example were evaluated. The specific test results are shown in Table 1.

[0104] Table 1: Appearance and antibacterial performance of Examples 1-5 and Comparative Examples 1-3

[0105]

[0106] As shown in Table 1, the digitally printed photocatalytic decals of Examples 1-3 are intact, with no penetration on the back; the decals of the prepared photocatalytic ceramic products are also intact, without iridescence, and have good photocatalytic antibacterial properties. Since Example 4 does not contain a photocatalytic promoter, the antibacterial properties of the product are significantly reduced; since Example 5 does not contain a tracer, the transfer effect cannot be accurately determined, resulting in uneven thickness of the photocatalytic material, resulting in iridescence.

[0107] Since Comparative Example 1-2 does not contain an ultraviolet absorber, the layer structure of the flower paper is destroyed, the flower paper cracks, the photocatalytic material is lost and the thickness is uneven, so the antibacterial performance is reduced and an iridescence phenomenon occurs.

[0108] Since Comparative Example 3 does not contain an ink adsorption layer, the back of the flower paper is infiltrated with photocatalytic materials and tracers, and the product exhibits cracking and iridescence, and the antibacterial performance is also reduced.

[0109] For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, without having to go through creative labor. Therefore, simple improvements made to the present invention by those skilled in the art based on the disclosure of the present invention should be within the protection scope of the present invention. The above embodiments are preferred embodiments of the present invention, and all processes similar to the present invention and equivalent changes made should belong to the protection scope of the present invention.

Claims

1. A digital printing photocatalytic decal, characterized in that: It includes base paper, water-soluble glue layer, ink absorption layer, photocatalytic ink layer and cover oil layer from bottom to top; The photocatalytic ink layer is formed by inkjet printing of photocatalytic ink, and the raw materials of the photocatalytic ink include, by weight: 10-25 parts of nano-photocatalytic material; 1-5 parts of photocatalytic accelerator; 1-5 parts of ultraviolet absorber; 40-50 parts of quick-drying solvent; Dispersant 10-20 parts; 1-5 parts of low temperature frit; Tracer 0.1-0.5 parts; The ultraviolet absorber is selected from at least one of phenyl ester compounds, benzoazole compounds, and coumarin compounds; The nano-photocatalytic material is selected from at least one of anatase titanium dioxide, zinc oxide, titanium nitride and carbon nitride; The photocatalytic promoter is selected from at least one of indium oxide, cerium oxide, neodymium oxide, and nano-white carbon black; The tracer is selected from at least one of phenolphthalein red, methyl orange, phthalocyanine blue, indigo, and aniline black; The ink absorption layer is formed by coating an absorption slurry, and the raw materials of the absorption slurry include, by weight: 40-60 parts of comonomer; 2-5 parts of emulsifier; Initiator 0.7-0.8 parts; 40-60 parts of water; The comonomer is selected from at least one of methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, styrene, acrylonitrile, vinyl acetate, vinylidene chloride, acrylic acid, acrylamide, hydroxymethyl acrylamide, hydroxyethyl methacrylate, ethylene glycol dimethacrylate, and hydroxypropyl acrylate.

2. The digital printing photocatalytic decal according to claim 1, characterized in that: The phenyl ester compound is selected from at least one of p-hydroxybenzoate, p-hydroxystyrene ester, p-hydroxyphenylpyruvate, benzoate, and p-aminobenzoate; The benzoazole compound is selected from at least one of benzotriazole, benzothiazole and benzopyrazole; The coumarin compound is selected from coumarin and / or phenoxycoumarin.

3. The digital printing photocatalytic decal according to claim 1 or 2, characterized in that: The mass ratio of the nano-photocatalytic material to the ultraviolet absorber is (2-25):

1.

4. A method for preparing digital printing photocatalytic flower paper, characterized in that: The preparation method is used to prepare the digital printing photocatalytic flower paper according to any one of claims 1 to 3, comprising the following steps: First, water-soluble glue and raw materials for preparing ink absorption layer are coated on base paper in sequence to form water-soluble glue layer and ink absorption layer; then photocatalytic ink is inkjet printed to form photocatalytic ink layer; then cover oil is sprayed to form cover oil layer; finally, drying is performed to obtain the digitally printed photocatalytic flower paper; the thickness of the cover oil layer is 20-30 μm.

5. The method for preparing digital printing photocatalytic decal paper according to claim 4, characterized in that: The thickness of the water-soluble adhesive layer and the ink absorption layer are both 5-15 μm; the drying temperature is 75-85° C., and the drying time is 10-15 minutes.

6. A decal photocatalytic ceramic product, characterized in that: The invention comprises a ceramic substrate and a photocatalytic functional layer, wherein the photocatalytic functional layer is formed by baking the digitally printed photocatalytic decal paper according to any one of claims 1 to 3.

7. A method for preparing a decal photocatalytic ceramic product, characterized in that: The preparation method is used to prepare the decal photocatalytic ceramic product according to claim 6, comprising the following steps: The digitally printed photocatalytic decal paper is soaked in water to separate the base paper; the separated digitally printed photocatalytic decal paper is then pasted on the surface of the ceramic base body, scraped flat and then baked to obtain the decal photocatalytic ceramic product.

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