Ceramic tile with identifiable marking and preparation method thereof

Abstract

The present invention relates to the technical field of ceramic tiles, and in particular to a ceramic tile with an identifiable mark and a preparation method thereof. The preparation method comprises the following steps: S1. applying a top glaze to the surface of a brick blank, followed by inkjet printing; S2. printing a wrapped fluorescent glaze to obtain a marking pattern, and then applying a dry granular protective glaze, wherein the wrapped fluorescent glaze is prepared by mixing raw materials including the following components: wrapped fluorescent powder, printing powder, printing paste, and printing ink; S3. firing and polishing the brick blank obtained after step S2 to obtain a ceramic tile with an identifiable mark. A silicon source solution and a fluorescent powder suspension are mixed and then subjected to microwave hydrothermal treatment to completely hydrolyze ethyl orthosilicate. The hydrolyzed ultrafine quartz can be crystallized in a relatively short period of time, so that the ultrafine quartz is tightly wrapped around the fluorescent powder particles. The fluorescent powder is not easily denatured during subsequent high-temperature firing, and relevant product information can be easily obtained from the marking pattern printed by the wrapped fluorescent glaze during subsequent use.

Description

Technical Field

[0001] The present invention relates to the technical field of ceramic tiles, and in particular to a ceramic tile with an identifiable mark and a preparation method thereof. Background Art

[0002] Fluorescent materials are materials that emit light under ultraviolet light and absorb ultraviolet light (200-400nm). This light, which is invisible to the naked eye, absorbs a certain amount of energy, stimulating free electrons to emit visible light, producing fluorescent materials with varying hues. Once the ultraviolet light is removed, the fluorescence disappears. Fluorescent materials are typically calcined into a mixture of zinc, calcium, barium, or strontium sulfides, a small amount of a cosolvent (such as sodium chloride), and an activator (such as copper chloride). The color of the fluorescence varies depending on the nature of the activator and the composition of the fluorescent agent.

[0003] Ordinary phosphors, at room temperature, fluoresce under ultraviolet light, producing high brightness and clarity. This phosphor can be molded into various trademark designs and printed on stickers, providing a security feature for products, serving as a way to distinguish genuine goods. When the UV light source is removed, the fluorescent effect disappears without affecting the product's appearance. However, currently, ceramic tile manufacturers rarely use phosphor materials. Most typically write product information on the outer packaging, making it difficult to access after discarding the wrapping. Another method involves stamping the product trademark onto the back of the tile using a press, revealing the manufacturer and brand. However, after installation, the trademark is obscured by the tile's underside, making the original information inaccessible. This makes it difficult to locate the original manufacturer and brand when replacing damaged tiles.

[0004] To facilitate quick access to product information after installation, a fluorescent pattern can be printed on the surface of the tile, with the product information attached to a fluorescent QR code. However, at temperatures exceeding 900°C (primary firing is performed at 1190-1230°C), the phosphor's structure changes, oxidizing it and no longer fluorescing when exposed to ultraviolet light. To accommodate this characteristic, fluorescent marble tiles can be produced using a double or triple firing process. The solution is to first bisque-fire the tiles or fire the semi-finished products at 1190-1230°C, then print a layer of fluorescent pattern on the surface of the finished tile, apply a protective layer of dry particles, and then fire the tiles again in a 100-150m roller kiln at 800-900°C for a 30-50 minute firing cycle. This ensures that the dry particle protective layer melts and adheres to the phosphor powder on the tile surface, preserving the fluorescent effect. However, the above production process is complex and requires multiple firings, which increases the production process, heat and energy consumption, and increases labor and machinery costs. Summary of the Invention

[0005] The main purpose of the present invention is to provide a method for preparing ceramic tiles with identifiable markings and a preparation method thereof, aiming to improve the technical problem that the existing ceramic tiles with fluorescent marking recognition function have complex preparation processes and are prone to failure of the fluorescent effect.

[0006] To achieve the above object, the present invention provides a method for preparing a ceramic tile with an identifiable mark, comprising the following steps: S1. applying a glaze on the surface of the tile, and then performing inkjet printing;

[0007] S2. After printing the encapsulated fluorescent glaze, a logo pattern is obtained after identification of the tile information, and then a dry protective glaze is applied. The encapsulated fluorescent glaze is prepared by mixing raw materials comprising the following components: encapsulated fluorescent powder, printing powder, printing paste and printing ink;

[0008] S3. The bricks obtained after step S2 are fired and polished to obtain the ceramic bricks with identifiable markings.

[0009] The ceramic tiles in this solution are coated with a wrapped fluorescent glaze, which is specifically an ultra-fine cristobalite wrapped fluorescent glaze slurry. After the glaze is applied to the brick, inkjet printing is performed, and then the wrapped fluorescent glaze is screen-printed on top of it to form a two-dimensional code pattern (logo pattern). When the two-dimensional code pattern is irradiated with ultraviolet light, various product information such as its manufacturer and model number can be identified. When the ultraviolet light irradiation is turned off, the fluorescence disappears immediately, which does not affect the use of the product. The above-mentioned two-dimensional code pattern (logo pattern) can also be a barcode pattern, and the user can obtain product information from it. The wrapped fluorescent glaze is made by mixing wrapped fluorescent powder, printing powder, printing paste and printing oil evenly, and has a good printing effect. The printing powder plays a suspension role in the fluorescent powder glaze slurry, keeping the wrapped fluorescent glaze slurry uniform and not precipitating. During the firing process, it melts into a transparent glass phase, which will not cover the pattern, and has a high-temperature bonding effect, bonding the wrapped fluorescent powder particles to the brick without falling off.

[0010] After printing the wrapped fluorescent glaze, a dry granulator is used to spread high-temperature transparent dry granular protective glaze as a protective layer. After one high-temperature calcination, a hard glass protective layer is formed on the surface of the tile. This can protect the fluorescent powder from being damaged by friction during the use of the product, and prevent the fluorescent powder from falling off and becoming ineffective after long-term use of the tile.

[0011] Preferably, the preparation of the encapsulated phosphor comprises the following steps: S21. mixing ethyl orthosilicate with a solvent and stirring the mixture to obtain a silicon source solution;

[0012] S22. The phosphor is mixed with deionized water and stirred to obtain a phosphor suspension;

[0013] S23. The phosphor suspension is added to the silicon source solution while stirring, and the catalyst is added and stirred to obtain a phosphor-coated precursor solution;

[0014] S24. The phosphor-coated precursor solution is hydrothermally treated;

[0015] S25. Adding a demulsifier and a precipitant to the phosphor-coated precursor solution after hydrothermal treatment, and adjusting the pH value of the phosphor-coated precursor solution to 9.5-10.5 for precipitation reaction, stirring and ultrasonically dispersing, and letting stand to obtain a mixed solution containing a precipitate;

[0016] S26. The mixed solution containing the precipitate is centrifuged, washed, filtered and dried to obtain an encapsulated phosphor precursor powder;

[0017] S27. Sintering the encapsulated phosphor precursor powder in a reducing atmosphere and an inert atmosphere, crushing and sieving the encapsulated phosphor after cooling to obtain the encapsulated phosphor.

[0018] In the preparation process of the encapsulated phosphor of the present invention, ethyl orthosilicate and ethanol are first mixed evenly; phosphor is added to deionized water, dispersed and stirred evenly to prepare a phosphor suspension, which is then added to a ethyl orthosilicate microemulsion and mixed; under the catalytic action of a catalyst (the catalyst can be added to the silicon source solution first or later), the surface of the phosphor is modified and acts as a crystal nucleating agent to cause crystal growth; ethyl orthosilicate decomposes in deionized water to precipitate ultrafine quartz, which is wrapped around the phosphor crystals; and then a microwave hydrothermal method is used to treat the phosphor encapsulation precursor solution, which has the advantages of small crystal loss, high encapsulation rate, good dispersibility, less agglomeration, and more consistent encapsulation. The method has the advantages of high density, rapid heating, short reaction time, and uniform phosphor particle size distribution. After hydrothermal treatment, a demulsifier is added, and a precipitant is added after approximately 10 minutes to produce a precipitate. The precipitate is centrifuged, washed with water, filtered, and dried to obtain an encapsulated phosphor precursor powder (crystals). Argon, an inert gas, is then added for protection, while hydrogen (H2) is added to ensure a reducing atmosphere. The encapsulated phosphor precursor powder is microwave-sintered to convert the encapsulated quartz crystals into cristobalite crystals, which facilitates the production of an encapsulated phosphor with a stable molecular structure and reduces damage to the encapsulated structure during mixing and stirring of the encapsulated phosphor particles during use. Because the resulting cristobalite-encapsulated phosphor has high thermal stability and its molecular structure is not easily altered at high temperatures, it can be directly applied in the ceramic field with a single high-temperature firing.

[0019] The inert gas atmosphere in this solution uses argon as the main gas, which can meet the requirements of the reaction while also reducing the danger of the mixture. In addition to using inert gas for protection, this solution also uses microwave sintering in a reducing atmosphere to effectively prevent the phosphor from undergoing oxidation reactions under high temperatures, thereby preventing the phosphor from failing in fluorescence conversion. Microwave sintering is a method of sintering materials using microwave heat energy to heat them to the sintering temperature to achieve densification. This method improves sintering efficiency and reduces damage to the inclusions caused by physical stirring during the use of the phosphor. It has the characteristics of fast heating speed, high energy utilization, environmental protection and no pollution, and the sintered material is pure and free of impurities. The encapsulated phosphor produced in this solution has a layer of ultrafine transparent cristobalite crystals on the outer surface of the phosphor particles. On the one hand, cristobalite has high-temperature stability, which can prevent other molten liquid phase materials from corroding the phosphor, thereby avoiding damage to the phosphor's crystal structure. On the other hand, the dense cristobalite crystals can hinder the oxidation of the phosphor at high temperatures, so that the fluorescence conversion efficiency can be maintained.

[0020] Preferably, in step S21, the volume ratio of the tetraethyl orthosilicate and the solvent when mixed is (1-4):1; the solvent is ethanol, diethyl ether, isopropyl alcohol, or cyclohexane. When the raw materials for the preparation of the silicon source are limited to the above volume ratio range, the obtained silicon source has a better effect on the encapsulation of the phosphor in the subsequent reaction. The tetraethyl orthosilicate used to prepare the silicon source is flammable and will become turbid in humid air. It will become clear after standing and produce silicic acid precipitation. In this solution, ethanol, diethyl ether, isopropyl alcohol, and cyclohexane are selected for mixing and stirring with it to prevent precipitation.

[0021] Preferably, in step S22, the phosphor accounts for 5-10% of the deionized water by mass, so that the phosphor is better dispersed in the deionized water, which is conducive to the silicon source encapsulating the phosphor.

[0022] Preferably, the phosphor is zinc sulfide phosphor; in step S23, the molar ratio of Zn ions in the phosphor suspension to Si ions in the silicon source solution is 1:(5-10); and the catalyst is potassium fluoride. When the Zn:Si ratio is 1:(5-10), the cristobalite in the silicon source can better encapsulate the phosphor, resulting in fewer voids. Therefore, during the subsequent firing process, the phosphor is less susceptible to denaturation under high temperature conditions, providing a better identification effect. The use of potassium fluoride as the catalyst in this solution improves the physical affinity between the phosphor and the ultrafine quartz coating, facilitating the coating of the phosphor by the quartz microemulsion (silicon source solution).

[0023] In addition to zinc sulfide phosphor, this solution can also use uranium oxide phosphor.

[0024] Preferably, in step S24, the hydrothermal treatment is microwave hydrothermal treatment, with a fill level of 70-80%, a temperature of 150-250°C, a pressure of 0.05-0.10 MPa, and a duration of 2-6 hours. The demulsifier is acetone, cyclohexanone, or hexafluorobutyl methacrylate, and the precipitant is an aqueous ammonia solution or a sodium hydroxide solution. Heating and pressurizing the phosphor-coated precursor solution in a microwave hydrothermal reactor can promote the crystallization reaction rate in a favorable direction and increase the conversion rate of ultrafine quartz. Specifically, a microwave hydrothermal duration of 2-6 hours yields optimal results.

[0025] Preferably, in step S26, the drying process is: drying at 150-200° C. for 1-3 hours. The drying process can remove excess moisture in the encapsulated phosphor precursor powder, facilitating the subsequent sintering reaction.

[0026] Preferably, in step S27, the sintering is microwave sintering at a temperature of 1100-1300°C for 10-20 minutes. After crushing and sieving, the resulting ultrafine cristobalite-encapsulated phosphor has a size of 50-100 μm. The microwave sintering temperature of 1100-1300°C in this solution promotes the formation of stable chemical bonds between ions. The particle size of the encapsulated phosphor after crushing and sieving is controlled within the range of 50-100 μm. If the particle size is too large, it is inconvenient for use in the ceramic tile industry. If the particle size is too small, the phosphor absorbs low energy, exhibits weak fluorescence properties, and exhibits poor display effects when irradiated with ultraviolet light.

[0027] Preferably, in step S3, the firing temperature is 1190-1230° C. Since the encapsulated phosphor is used, the properties of the phosphor will not change after high-temperature firing. Therefore, the firing temperature of the ceramic tiles in this solution is 1190-1230° C., and the obtained ceramic tiles have good quality.

[0028] In addition, the present invention also provides a ceramic tile with an identifiable mark, produced by any of the above-mentioned methods for producing a ceramic tile with an identifiable mark. The ceramic tile with an identifiable mark can effectively reflect the product information of the ceramic tile. With reference to the above-mentioned solution, since the ceramic tile with an identifiable mark adopts all of the above-mentioned technical solutions, it has all the effects brought about by the above-mentioned technical solutions, which will not be detailed here.

[0029] Compared with the prior art, the technical solution of the present invention has the following beneficial effects: the present invention utilizes a microemulsion co-precipitation method to first prepare a microemulsion of a silicon source solution, which is then mixed and stirred with a phosphor suspension to form a phosphor coating precursor. Due to the addition of deionized water to the phosphor suspension, the ultrafine quartz microemulsion generated after the hydrolysis of ethyl orthosilicate has adhesive properties. Microwave hydrothermal treatment can promote the complete hydrolysis of ethyl orthosilicate, and during the formation of ultrafine quartz, a transition phase can be formed with ethyl orthosilicate. The ultrafine quartz after heating and hydrolysis can crystallize in a relatively short period of time, promoting the densification of the inclusions, thereby uniformly embedding the phosphor crystals within the coating layer, that is, the ultrafine quartz tightly wraps around each phosphor particle. Therefore, the ultrafine quartz has a better protective effect on the phosphor, and the phosphor is not easily denatured during subsequent high-temperature firing. During subsequent use, relevant product information can be easily obtained from the logo pattern printed on the encapsulated fluorescent glaze. DETAILED DESCRIPTION

[0030] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0031] In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0032] A method for preparing a ceramic tile with an identifiable mark comprises the following steps:

[0033] S1. Use a press to press the powder into a brick blank, dry it in a drying kiln, and then dry the brick blank for use (moisture content is controlled at 0.3-0.5%, and drying strength is 1.3-1.8 MPa); the brick blank can be 600*900mm in size and 12mm thick. In other embodiments, it can also be any other size and thickness; then, glaze is applied on the surface of the brick blank (the amount of glaze applied is 220-300 grams per brick); inkjet printing is performed on the surface of the glaze (layer) using an inkjet printer to obtain a pattern printing layer.

[0034] S2. Print a wrapped fluorescent glaze on the surface of the pattern printing layer with a screen printing machine to obtain a QR code pattern with tile product information (such as manufacturer, model, usage instructions, etc.). Continue to use a dry granulator to apply a layer of 0.8-1.2mm thick (high-temperature transparent) dry granular protective glaze on the surface of the above brick. Spray glue on the surface of the dry granular protective glaze. The amount of glue per brick is 100-150 grams. The purpose is to fix the QR code pattern and the dry granular protective layer.

[0035] Preparation of ultrafine cristobalite encapsulated fluorescent glaze: Encapsulated fluorescent powder, printing powder, printing paste and printing oil are added into a mixing tank in different proportions and stirred to prepare encapsulated fluorescent glaze slurry.

[0036] S3. The above-mentioned bricks enter the roller kiln and are fired at 1190-1230℃ in a reducing atmosphere for 55-70min. They are kept at the highest firing temperature for 10-20min. After polishing and waxing, ceramic tiles with identifiable markings are obtained.

[0037] The preparation method of ultrafine cristobalite-wrapped fluorescent glaze comprises the following steps:

[0038] S21. Prepare a silicon source solution: dissolve ethyl orthosilicate and ethanol in a volume ratio of (1-4):1 and stir evenly to obtain a microemulsion of the silicon source solution.

[0039] S22. Prepare a phosphor suspension: The main component of the phosphor is zinc sulfide (ZnS: Cu, Er, Ag). 5-10% by mass of the phosphor is mixed with deionized water and stirred until uniformly dispersed to obtain a phosphor suspension.

[0040] S23. Slowly add the phosphor suspension to the silicon source solution microemulsion while stirring, at a molar ratio of Zn:Si = 1:5-10. Add potassium fluoride as a catalyst, and stir to form a mixed microemulsion of the phosphor suspension and silicon source solution, thereby obtaining a phosphor coating precursor solution. The stirring speed is 150-250 r / min.

[0041] S24. The phosphor-coated precursor solution is placed in a microwave hydrothermal reactor, controlling the filling degree to 70-80%, subjected to microwave hydrothermal treatment at a hydrothermal temperature of 150-250°C, a pressure of 0.05-0.10MP, and a microwave heating time of 2-6h;

[0042] S25. A demulsifier, acetone, and a precipitant, ammonia solution, were added to the phosphor-coated precursor solution after hydrothermal treatment, and the pH value was adjusted to 9.5-10.5. A precipitation reaction was performed, and the mixture was stirred and ultrasonically dispersed for 28-33 min. The dispersed solution was allowed to stand for 15-25 min to obtain a mixed solution containing a precipitate of an ultrafine cristobalite-coated phosphor.

[0043] S26. The mixed solution containing the precipitate is centrifuged, washed with water, filtered, and dried at 150-200° C. for 1-3 hours to obtain a cristobalite-encapsulated phosphor precursor powder.

[0044] S27. Argon and hydrogen are introduced to create a reducing and inert atmosphere, and the encapsulated phosphor precursor powder is microwave-sintered at a temperature of 1100-1300°C for 10-20 minutes. The powder is then naturally cooled to room temperature. The sintered powder is crushed, and particles with a size of 50-100 μm are screened out for later use, yielding ultrafine cristobalite-encapsulated phosphor particles. The resulting encapsulated phosphor exhibits high thermal stability and a molecular structure that is not easily altered at high temperatures. It can be used in ceramic applications and is compatible with existing single-shot high-temperature firing processes.

[0045] 30 g of the encapsulated phosphor particles prepared in this solution were spread on a 100 cm 2 On a white porcelain plate, when irradiated under fluorescent light and 365nm ultraviolet light respectively, there is no fluorescent effect under fluorescent light, but there is obvious green visible fluorescence under 365nm ultraviolet light. When the ultraviolet light irradiation is cancelled, the fluorescent effect disappears.

[0046] The technical solutions of the present invention are further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention.

[0047] In the following embodiments, a group of blank raw materials and glazes are listed for the production of ceramic tiles. In other embodiments, the chemical composition of the blank powder and glaze can be adaptively adjusted.

[0048] Some chemical compositions of the powder for blanks are as follows by mass percentage:

[0049] <![CDATA[Si02]]> <![CDATA[Al2O3]]> <![CDATA[Fe2O3]]> <![CDATA[TiO2]]> CaO MgO <![CDATA[K2O]]> <![CDATA[Na2O]]> L.O.I 66.18％ 20.51％ 0.72％ 0.18％ 0.53％ 0.89％ 3.61％ 2.60％ 4.74％

[0050] Some of the chemical components of the glaze are as follows by mass percentage:

[0051] <![CDATA[Si02]]> <![CDATA[Al2O3]]> <![CDATA[Fe2O3]]> ZnO CaO MgO <![CDATA[K2O]]> <![CDATA[Na2O]]> BaO L.O.I 50.39％ 21.34％ 0.17％ 2.58％ 5.58％ 4.09％ 2.18％ 3.11％ 3.45％ 6.27％

[0052] The raw materials of the (high-temperature transparent) dry granular protective glaze include, by weight, 30-40 parts of potassium feldspar, 12-25 parts of nepheline, 8-10 parts of kaolin, 5-10 parts of calcined clay, 4-8 parts of aluminum oxide, 5-8 parts of dolomite, 6-10 parts of calcined talc, 8-12 parts of calcite, 8-15 parts of barium carbonate, and 3-6 parts of zinc oxide. The (high-temperature transparent) dry granular protective glaze of the following embodiment specifically comprises 38 parts of potassium feldspar, 12 parts of nepheline, 8 parts of kaolin, 5 parts of calcined clay, 4 parts of aluminum oxide, 7 parts of dolomite, 6 parts of calcined talc, 8 parts of calcite, 8 parts of barium carbonate, and 4 parts of zinc oxide.

[0053] The raw materials for the encapsulated fluorescent glaze, by weight, include: 20-80% encapsulated fluorescent powder, 20-80% printing powder, with printing paste and printing ink accounting for 30-50% of the total weight of the two. The encapsulated fluorescent glaze in the following example specifically comprises 80% encapsulated fluorescent powder and 20% printing powder, with the printing paste and printing ink each accounting for 40% of the total weight. The raw materials for the printing powder, by weight, include: 28-35 parts potassium feldspar, 12-18 parts sodium feldspar, 8-10 parts kaolin, 6-12 parts wollastonite, 4-12 parts calcined clay, 4-8 parts alumina, 8-16 parts calcined talc, 8-12 parts calcite, 4-8 parts strontium carbonate, and 8-12 parts zinc oxide. The printing powder of the following examples specifically comprises 30 parts of potassium feldspar, 15 parts of sodium feldspar, 8 parts of kaolin, 6 parts of wollastonite, 5 parts of calcined clay, 4 parts of aluminum oxide, 10 parts of calcined talc, 8 parts of calcite, 6 parts of strontium carbonate, and 8 parts of zinc oxide.

[0054] Example 1

[0055] A method for preparing a ceramic tile with an identifiable mark comprises the following steps:

[0056] S1. The powder is pressed into a brick by a press, the brick is dried, and then the surface of the brick is glazed, and the surface of the glaze is printed with an inkjet printer;

[0057] S2. Continue to print the wrapped fluorescent glaze on the surface of the brick to obtain a QR code pattern with tile product information, and then continue to cloth dry granular protective glaze and spray glue on the surface of the dry granular protective glaze;

[0058] Preparation of the wrapped fluorescent glaze: mixing the wrapped fluorescent powder, printing powder, printing paste and printing ink to prepare the wrapped fluorescent glaze;

[0059] S3. The above-mentioned bricks are fired in a roller kiln at 1200°C in a reducing atmosphere with a firing cycle of 70 minutes, kept at the highest firing temperature for 20 minutes, and polished to obtain ceramic tiles with identifiable markings.

[0060] The method for preparing the encapsulated phosphor comprises the following steps:

[0061] S21. Ethyl orthosilicate and ethanol were mixed in a volume ratio of 1:1 to obtain a silicon source solution;

[0062] S22. A 10% mass ratio of zinc sulfide phosphor and deionized water were mixed and stirred to obtain a phosphor suspension;

[0063] S23. In a molar ratio of Zn:Si = 1:3, the phosphor suspension was added to the silicon source solution, and potassium fluoride catalyst was added and stirred to obtain a phosphor coating precursor solution;

[0064] S24. The phosphor-coated precursor solution was placed in a microwave hydrothermal reactor, controlling the filling degree to 80%, and subjected to microwave hydrothermal treatment at a hydrothermal temperature of 250°C, a pressure of 0.02MPa, and a microwave heating time of 4h;

[0065] S25. A demulsifier acetone was added to the hydrothermal treatment phosphor-coated precursor solution, and then a precipitant ammonia solution was added, and the pH value was adjusted to 9 for precipitation reaction, stirred and ultrasonically dispersed for 30 min, and the dispersed solution was allowed to stand for 25 min to obtain a mixed solution containing a precipitate;

[0066] S26. The mixed solution containing the precipitate was centrifuged, washed with water, filtered, and dried at 180°C for 2h to obtain an encapsulated phosphor precursor powder;

[0067] S27. Introduce argon and hydrogen, with the ratio of argon to hydrogen in the mixed gas being 6:1, and microwave sinter the encapsulated phosphor precursor powder at a temperature of 1030°C for 30 minutes. Cool it naturally to room temperature along with the furnace, and crush the sintered powder. Screen out particles with a size of 50-100 μm for later use to obtain encapsulated phosphor particles.

[0068] Example 2

[0069] A method for preparing a ceramic tile with an identifiable mark comprises the following steps:

[0070] S1. The powder is pressed into a brick by a press, the brick is dried, and then the surface of the brick is glazed, and the surface of the glaze is printed with an inkjet printer;

[0071] S2. Continue printing the wrapped fluorescent glaze on the surface of the brick to obtain a QR code pattern with tile product information, and then continue to cloth dry granular protective glaze and spray glue on the surface of the dry granular protective glaze;

[0072] Preparation of the wrapped fluorescent glaze: mixing the wrapped fluorescent powder, printing powder, printing paste and printing ink to prepare the wrapped fluorescent glaze;

[0073] S3. The above-mentioned bricks are fired in a roller kiln at 1190°C in a reducing atmosphere with a firing cycle of 60 minutes, kept at the highest firing temperature for 15 minutes, and polished to obtain ceramic tiles with identifiable markings.

[0074] The method for preparing the encapsulated phosphor comprises the following steps:

[0075] S21. Ethyl orthosilicate and isopropyl alcohol were mixed in a volume ratio of 2:1 to obtain a silicon source solution;

[0076] S22. Blend 5% by mass of zinc sulfide phosphor and deionized water and stir evenly to obtain a phosphor suspension.

[0077] S23. In a molar ratio of Zn:Si = 1:5, the phosphor suspension was added to the silicon source solution, potassium fluoride catalyst was added and stirred to obtain a phosphor-encapsulated precursor solution;

[0078] S24. The phosphor-coated precursor solution was placed in a microwave hydrothermal reactor, controlling the filling degree to 76%, and subjected to microwave hydrothermal treatment at a temperature of 200°C, a pressure of 0.05MPa, and a microwave heating time of 5h.

[0079] S25. After hydrothermal treatment, the phosphor-coated precursor solution was added with a demulsifier, cyclohexanone, and then a precipitant, sodium hydroxide solution, was added and the pH value was adjusted to 10 for precipitation reaction. The mixture was stirred and ultrasonically dispersed for 33 min, and the dispersed solution was allowed to stand for 22 min to obtain a mixed solution containing a precipitate.

[0080] S26. The mixed solution containing the precipitate was centrifuged, washed with water, filtered, and dried at 150°C for 3h to obtain an encapsulated phosphor precursor powder;

[0081] S27. Introduce argon and hydrogen, with the ratio of argon to hydrogen in the mixed gas being 6:1, and microwave sinter the encapsulated phosphor precursor powder at a temperature of 1200°C for 12 minutes. Cool it naturally to room temperature along with the furnace, and crush the sintered powder. Screen out particles with a particle size of 50-100 μm for later use to obtain encapsulated phosphor particles.

[0082] Example 3

[0083] A method for preparing a ceramic tile with an identifiable mark comprises the following steps:

[0084] S1. The powder is pressed into a brick by a press, the brick is dried, and then the surface of the brick is glazed, and the surface of the glaze is printed with an inkjet printer;

[0085] S2. Continue printing the wrapped fluorescent glaze on the surface of the brick to obtain a QR code pattern with tile product information, and then continue to cloth dry granular protective glaze and spray glue on the surface of the dry granular protective glaze;

[0086] Preparation of the wrapped fluorescent glaze: mixing the wrapped fluorescent powder, printing powder, printing paste and printing ink to prepare the wrapped fluorescent glaze;

[0087] S3. The above-mentioned bricks are fired in a roller kiln at 1230°C in a reducing atmosphere with a firing cycle of 55 minutes, kept at the highest firing temperature for 10 minutes, and polished to obtain ceramic tiles with identifiable markings.

[0088] The method for preparing the encapsulated phosphor comprises the following steps:

[0089] S21. Ethyl orthosilicate and ethanol were mixed in a volume ratio of 3:1 to obtain a silicon source solution;

[0090] S22. A 7% mass ratio of zinc sulfide phosphor and deionized water were mixed and stirred to obtain a phosphor suspension;

[0091] S23. In a molar ratio of Zn:Si = 1:8, the phosphor suspension was added to the silicon source solution, and potassium fluoride catalyst was added and stirred to obtain a phosphor-encapsulated precursor solution;

[0092] S24. The phosphor-coated precursor solution was placed in a microwave hydrothermal reactor, controlling the filling degree to 72%, and subjected to microwave hydrothermal treatment at a hydrothermal treatment temperature of 210 ° C, a pressure of 0.1 MPa, and a microwave heating time of 5h;

[0093] S25. A demulsifier, acetone, was added to the hydrothermally treated phosphor-coated precursor solution, and then an ammonia solution was added as a precipitant, and the pH value was adjusted to 9.5 for precipitation reaction. The mixture was stirred and ultrasonically dispersed for 28 minutes, and the dispersed solution was allowed to stand for 15 minutes to obtain a mixed solution containing a precipitate.

[0094] S26. The mixed solution containing the precipitate was centrifuged, washed with water, filtered, and dried at 190°C for 1 hour to obtain an encapsulated phosphor precursor powder;

[0095] S27. Introduce argon and hydrogen, with the ratio of argon to hydrogen in the mixed gas being 6:1, and microwave sinter the encapsulated phosphor precursor powder at a temperature of 1100°C for 20 minutes. Cool it naturally to room temperature along with the furnace, and crush the sintered powder. Screen out particles with a particle size of 50-100 μm for later use to obtain encapsulated phosphor particles.

[0096] Example 4

[0097] A method for preparing a ceramic tile with an identifiable mark comprises the following steps:

[0098] S1. The powder is pressed into a brick by a press, the brick is dried, and then the surface of the brick is glazed, and the surface of the glaze is printed with an inkjet printer;

[0099] S2. Continue to print the wrapped fluorescent glaze on the surface of the brick to obtain a QR code pattern with tile product information, and then continue to cloth dry granular protective glaze and spray glue on the surface of the dry granular protective glaze;

[0100] Preparation of the wrapped fluorescent glaze: mixing the wrapped fluorescent powder, printing powder, printing paste and printing ink to prepare the wrapped fluorescent glaze;

[0101] S3. The above-mentioned bricks are fired in a roller kiln at 1215°C in a reducing atmosphere with a firing cycle of 68 minutes, kept at the highest firing temperature for 20 minutes, and polished to obtain ceramic tiles with identifiable markings.

[0102] The method for preparing the encapsulated phosphor comprises the following steps:

[0103] S21. Ethyl orthosilicate and cyclohexane were mixed in a volume ratio of 4:1 to obtain a silicon source solution;

[0104] S22. The mass ratio of 8% zinc sulfide phosphor and deionized water were mixed and stirred to obtain a phosphor suspension;

[0105] S23. In a molar ratio of Zn:Si = 1:10, the phosphor suspension was added to the silicon source solution, potassium fluoride catalyst was added and stirred to obtain a phosphor-encapsulated precursor solution;

[0106] S24. The phosphor-coated precursor solution was placed in a microwave hydrothermal reactor, controlling the filling degree to 70%, and subjected to microwave hydrothermal treatment at a temperature of 230 ° C, a pressure of 0.07 MPa, and a microwave heating time of 6 h.

[0107] S25. To the hydrothermal treatment of the phosphor-coated precursor solution, a demulsifier of hexafluorobutyl methacrylate was added, and then an ammonia solution was added as a precipitant, and the pH value was adjusted to 10.5 for precipitation reaction. The mixture was stirred and ultrasonically dispersed for 31 minutes. The dispersed solution was allowed to stand for 20 minutes to obtain a mixed solution containing a precipitate.

[0108] S26. The mixed solution containing the precipitate was centrifuged, washed with water, filtered, and dried at 200°C for 2.5h to obtain an encapsulated phosphor precursor powder;

[0109] S27. Introduce argon and hydrogen, with the ratio of argon to hydrogen in the mixed gas being 6:1, and microwave sinter the encapsulated phosphor precursor powder at a temperature of 1300°C for 10 minutes. Cool it naturally to room temperature along with the furnace, and crush the sintered powder. Screen out particles with a size of 50-100 μm for later use to obtain encapsulated phosphor particles.

[0110] Comparative Example 1

[0111] The preparation steps and parameters in this comparative example are the same as those in Example 2, except that: this comparative example uses ordinary phosphor to be stirred and mixed with printing powder, printing paste and printing ink.

[0112] Comparative Example 2

[0113] The preparation steps and parameters in this comparative example are the same as those in Example 3, except that no precipitant is added in step S24 of this comparative example. At this time, the pH is 10, and no mixed solution containing precipitate can be obtained.

[0114] Comparative Example 3

[0115] The preparation steps and parameters in this comparative example are the same as those in Example 3, except that: in this comparative example, the catalyst potassium fluoride is not added in step S23.

[0116] The ceramic tiles with identifiable markings of Examples 1-4 and Comparative Examples 1-3 were subjected to performance tests, and the specific test results are shown in the following table:

[0117]

[0118]

[0119] Note: The marking effects of the above ceramic tiles were observed under 365nm ultraviolet light; and the markings of the above ceramic tiles had no fluorescent effect under fluorescent light.

[0120] The recognition success rate detection method is as follows: 20 groups of people are used to scan and identify the same ceramic tile with an identifiable mark multiple times (each group of people uses their own mobile phone to scan the code, and the scanning models are different). Each group of people scans and identifies the code 5 times, and the total number of scans and identifications is 100 times. If the product information of the ceramic tile is scanned and identified, it is recorded as a success. The proportion of successful identification times to the total number = recognition success rate.

[0121] The above test results indicate that uncoated phosphors, or those not prepared in strict accordance with the encapsulated phosphor preparation steps described in this solution, will oxidize and destroy their molecular structure during the high-temperature calcination of 1190-1230°C in a roller kiln during the ceramic tile firing process, resulting in a loss of fluorescent properties. However, the glaze made from the ultrafine cristobalite-encapsulated phosphors described in this solution maintains its original properties after high-temperature calcination, with a clearly visible fluorescent pattern that can be easily scanned and identified, thereby providing product information related to the ceramic tiles.

[0122] Example 5

[0123] The preparation steps and parameters in this embodiment are the same as those in Example 1, except that in step S23, the molar ratio of Zn ions to Si ions in this embodiment is adjusted to 1:7.

[0124] Example 6

[0125] The preparation steps and parameters in this embodiment are the same as those in Example 1, except that: in step S26, the microwave sintering parameters in this embodiment are adjusted to a microwave sintering temperature of 1235° C. and a heat preservation time of 18 minutes.

[0126] Example 7

[0127] The preparation steps and parameters in this embodiment are the same as those in Example 1, except that in step S24, an ammonia solution as a precipitant is added and the pH value is adjusted to 9.8 for precipitation reaction.

[0128] Example 8

[0129] The preparation steps and parameters in this embodiment are the same as those in Example 1, except that: in step S24, the hydrothermal treatment temperature in this embodiment is adjusted to 200° C. and the pressure is 0.08 MPa.

[0130] The ceramic tiles with identifiable markings of Examples 4-7 were subjected to performance tests, and the specific test results are shown in the following table:

[0131]

[0132] From the above test results, it can be concluded that by limiting the amount of Zn ions and Si ions in the phosphor suspension and silicon source solution, and optimizing the microwave sintering parameters, the amount of precipitant and the hydrothermal treatment parameters, the success rate of identification can be further improved.

[0133] Example 9

[0134] The preparation steps and parameters in this embodiment are the same as those in Example 1, except that: in this embodiment, preferably parameters and conditions are selected. In step S23, the phosphor suspension and the silicon source solution are mixed at a Zn:Si molar ratio of 1:6; in step S23, the microwave sintering parameter temperature is adjusted to 1200°C for 15 minutes; in step S23, a precipitant ammonia solution is added until the pH value is 10; in step S23, the microwave hydrothermal parameter temperature is adjusted to 200°C, the pressure is adjusted to 0.07 MPa, and the heating time is adjusted to 5 hours.

[0135] The ceramic tiles with identifiable markings produced in Example 9 were tested for performance. Under ultraviolet light, the displayed QR code was remarkably complete and accurately identified the tile information. In a test involving 100 groups of people, all were able to identify the product information, resulting in a 100% recognition success rate, completely eliminating the need for users to scan the code multiple times to obtain product information.

[0136] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention specification under the inventive concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for preparing a ceramic tile with an identifiable mark, characterized in that: The steps include: S1. Apply glaze on the surface of the brick and then perform inkjet printing; S2. After printing the encapsulated fluorescent glaze, a logo pattern is obtained after identification of the tile information, and then a dry protective glaze is applied. The encapsulated fluorescent glaze is prepared by mixing raw materials comprising the following components: encapsulated fluorescent powder, printing powder, printing paste and printing ink; S3. The brick obtained after step S2 is fired and polished to obtain the ceramic tile having an identifiable mark; The preparation of the encapsulated phosphor comprises the following steps: S21. Ethyl orthosilicate is mixed with a solvent and stirred to obtain a silicon source solution; S22. The phosphor is mixed with deionized water and stirred to obtain a phosphor suspension; S23. The phosphor suspension is added to the silicon source solution while stirring, and a catalyst is added and stirred to obtain a phosphor-coated precursor solution, wherein the phosphor is zinc sulfide phosphor, and the molar ratio of Zn ions in the phosphor suspension to Si ions in the silicon source solution is 1:(5-10); the catalyst is potassium fluoride; S24. The phosphor-coated precursor solution is hydrothermally treated; S25. Adding a demulsifier and a precipitant to the phosphor-coated precursor solution after hydrothermal treatment, and adjusting the pH value of the phosphor-coated precursor solution to 9.5-10.5 for precipitation reaction, stirring and ultrasonically dispersing, and letting stand to obtain a mixed solution containing a precipitate; S26. The mixed solution containing the precipitate is centrifuged, washed, filtered and dried to obtain an encapsulated phosphor precursor powder; S27. Sintering the encapsulated phosphor precursor powder in a reducing atmosphere and an inert atmosphere, crushing and sieving the encapsulated phosphor after cooling to obtain the encapsulated phosphor.

2. The method for preparing a ceramic tile with an identifiable mark according to claim 1, characterized in that: In step S21, the volume ratio of the ethyl orthosilicate and the solvent when mixed is (1-4):1; the solvent is ethanol, ether, isopropanol or cyclohexane.

3. The method for preparing a ceramic tile with an identifiable mark according to claim 1, characterized in that: In step S22, the phosphor accounts for 5-10% of the deionized water by mass.

4. The method for preparing a ceramic tile with an identifiable mark according to claim 1, wherein: In step S24, the hydrothermal treatment is microwave hydrothermal treatment, the filling degree of microwave hydrothermal treatment is 70-80%, the temperature is 150-250° C., the pressure is 0.05-0.10 MPa, and the time is 2-6 hours; The demulsifier is acetone, cyclohexanone or hexafluorobutyl methacrylate, and the precipitant is an ammonia solution or a sodium hydroxide solution.

5. The method for preparing a ceramic tile with an identifiable mark according to claim 1, characterized in that: In step S26, the drying process is: drying at 150-200° C. for 1-3 hours.

6. The method for preparing a ceramic tile with an identifiable mark according to claim 1, characterized in that: In step S27, the sintering is microwave sintering, the microwave sintering temperature is 1100-1300° C., and the heat preservation time is 10-20 minutes; the size of the encapsulated phosphor after sieving is 50-100 μm.

7. The method for preparing a ceramic tile with an identifiable mark according to claim 1, characterized in that: In step S3, the sintering temperature is 1190-1230°C.

8. A ceramic tile with an identifiable mark, characterized in that: The ceramic tile with identifiable marking is prepared by the method for preparing the ceramic tile with identifiable marking according to any one of claims 1 to 7.

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