Ceramic glaze for painting and preparation method thereof

Abstract

The invention discloses a ceramic glaze for painting and a preparation method thereof, and relates to the technical field of ceramic glazes, the ceramic glaze comprises the following raw materials: a basic glaze, a pigment, a fluidity regulator, a color stabilizer, a fluxing agent, a defoaming agent, a binder, a core functional group and an auxiliary synergistic component; the core functional component is prepared by compounding nano hydroxyapatite, polyether modified polysiloxane, rare earth oxide, nano silicon nitride and diethylene glycol monobutyl ether according to the mass ratio of (3 to 8): (1 to 3): (2 to 6): (2 to 5): (3 to 7); the auxiliary synergistic component is prepared by compounding sodium citrate, spodumene powder, metakaolin and sodium pyrophosphate according to the mass ratio of (0.2 to 0.5): (2 to 5): (3 to 6): (0.1 to 0.3). The ceramic glaze is high in color rendition degree, good in painting fluency, low in glaze defect rate and excellent in thermal stability.

Description

Technical Field

[0001] This invention relates to the field of ceramic glaze technology, and in particular to a ceramic glaze for painting and its preparation method. Background Technology

[0002] Ceramic painting is one of the core forms of expression in traditional Chinese ceramic art. Ceramic glaze, as the carrier and medium of painting, directly determines the color reproduction, line clarity, durability, and artistic expressiveness of the artwork. Traditional lead-containing ceramic glazes commonly suffer from problems such as excessive leaching of heavy metals like lead and cadmium, unstable color development leading to smudging, and poor weather resistance, severely hindering the green development of the ceramic painting industry. It is under these circumstances that lead-free boron glazes and feldspar glazes have become the mainstream ceramic glazes for painting. However, existing lead-free boron glazes are prone to pinholes during low-temperature firing, and excessive fluidity during high-temperature firing leads to blurred lines; feldspar glazes suffer from dull colors, weak adhesion to the body, and easy detachment of painted patterns during use.

[0003] In addition to the inherent defects of lead-free boron glazes and feldspar glazes mentioned above, existing lead-free ceramic glazes for painting also suffer from several common problems, further limiting their practical application: First, insufficient color stability. Whether it is lead-free boron glaze or feldspar glaze, at the conventional firing temperature of 1100-1300℃, the pigments are prone to oxidation, decomposition, or migration, especially bright pigments such as bright red and royal blue. After firing, they are prone to dull color and obvious color difference, failing to accurately reproduce the artist's color expression intention. Second, poor painting operability. The fluidity of the glaze is difficult to control precisely. Either the fluidity is too strong, causing the lines to bleed and the boundaries to blur after the brushstroke, making it impossible to complete fine line drawing, or the fluidity is too strong. The following issues arise: First, the lead-free glaze is too weak, leading to stuttering brushstrokes and uneven glazing, affecting the smoothness of the painting. Second, the glaze performance is weak; lead-free boron glaze is prone to running at high temperatures and pinholes at low temperatures, while feldspar glaze is prone to cracking and delamination. Moreover, both types of glazes generally have low hardness and insufficient wear resistance and acid and alkali resistance, resulting in glaze scratches and color fading in paintings during long-term preservation. Third, the preparation and compatibility are poor; some lead-free glazes have complex preparation processes, requiring the addition of special additives, which increases the preparation cost. Furthermore, most glazes have limited compatibility with ceramic bodies, and cannot be simultaneously adapted to various commonly used bodies such as celadon, white porcelain, and purple clay, making it difficult to meet the diverse needs of small and medium-sized studios and individual creators.

[0004] Therefore, developing a ceramic glaze for painting that is lead-free and environmentally friendly, has stable color development, controllable fluidity, no glaze defects, strong adhesion to the body, excellent weather resistance, simple preparation, and wide applicability, as well as its preparation method, has become an important technical issue that urgently needs to be addressed in the field of ceramic glazes. Summary of the Invention

[0005] To address the technical problems of existing ceramic glazes for painting, such as poor color stability, difficulty in controlling fluidity, easy defects in the glaze surface, insufficient environmental protection, and limited practicality, this invention provides a ceramic glaze for painting and its preparation method. By optimizing the formula composition and preparation process, the invention achieves a synergistic improvement in the smoothness of glaze painting, color stability, glaze surface strength, and environmental protection. At the same time, it simplifies the preparation process, reduces the firing difficulty, and meets the needs of ceramic painting in different scenarios.

[0006] To achieve the above objectives, the present invention provides a ceramic glaze for painting, comprising, by weight, the following raw materials: 72-78 parts of base glaze, 12-18 parts of colorant, 3-6 parts of flow modifier, 2-4 parts of color stabilizer, 2-3 parts of flux, 0.3-0.8 parts of defoamer, 0.8-1.5 parts of binder, 1.1-2.9 parts of core functional component, and 5.3-11.9 parts of auxiliary synergistic component; wherein the core functional component is composed of nano-hydroxyapatite, polyether-modified polysiloxane, rare earth oxide, nano-silicon nitride, and diethylene glycol butyl ether in a weight ratio of (3-8):(1-3):(2-6):(2-5):(3-7); wherein the auxiliary synergistic component is composed of sodium citrate, spodumene powder, metakaolin, and sodium pyrophosphate in a weight ratio of (0.2-0.5):(2-5):(3-6):(0.1-0.3).

[0007] Preferably, the base glaze is composed of the following raw materials by weight: 28-32 parts quartz sand, 20-26 parts feldspar, 18-22 parts kaolin, 10-13 parts calcite, 7-10 parts talc, and 5-7 parts alumina.

[0008] Preferably, the colorant is a mixture of cobalt oxide and iron oxide in a mass ratio of 1:(1-2).

[0009] Preferably, the flowability regulator is a mixture of sodium carboxymethyl cellulose and bentonite in a mass ratio of 1:1.

[0010] Preferably, the color stabilizer is a mixture of zirconium oxide and silicon dioxide in a mass ratio of 1:2.

[0011] Preferably, the flux is a mixture of borax and lithium carbonate in a mass ratio of 2:1.

[0012] Preferably, the defoamer is polydimethylsiloxane ZZSIL®201-12500.

[0013] Preferably, the adhesive is polyvinyl alcohol 400.

[0014] Preferably, the average particle size of the nano-hydroxyapatite is 10-80 nm; the polyether-modified polysiloxane is BYK-333; the rare earth oxide is cerium oxide with an average particle size of 20-60 nm; the average particle size of the nano-silicon nitride is 20-70 nm; the particle size of the spodumene powder is 500-800 mesh; and the particle size of the metakaolin is 800-1000 mesh.

[0015] Another object of the present invention is to provide a method for preparing the aforementioned ceramic glaze for painting, comprising the following steps: Step S1, Raw Material Pretreatment: Select quartz sand, feldspar, kaolin, calcite, talc, and alumina respectively, remove impurities, and place them in a drying oven at 105-110℃ for 2-3 hours. After drying, put each raw material into a pulverizer for crushing, and then pass them through a 200-mesh sieve. The residue is returned to the pulverizer for re-crushing to ensure that the particle size of each raw material is uniform and free of coarse particles. Then, mix the crushed raw materials evenly according to the basic glaze ratio to obtain mixed basic raw materials. At the same time, add the spodumene powder, metakaolin, flux, and other auxiliary synergistic components to the mixture. Mix the basic raw materials together until homogeneous and set aside. Select cobalt oxide and iron oxide, and mix them evenly according to the mass ratio to obtain a composite colorant. Place the composite colorant in a drying oven and dry it at 100-105℃ for 1-1.5 hours. Then, put the dried composite colorant into a ball mill, add a small amount of deionized water, and add sodium citrate from the auxiliary synergistic component. Ball mill for 30-60 minutes at a speed of 200-300 r / min and a ball-to-material ratio of 5:1. After ball milling, obtain a colorant slurry with a solid content of 60%-70% and set aside. The flow modifier, color stabilizer, flux, defoamer, and binder are placed in a drying oven and dried until the moisture content is ≤0.5%. Then, they are pulverized in a pulverizer until the particle size is ≤0.1μm and set aside. At the same time, the nano-hydroxyapatite, cerium oxide, and nano-silicon nitride in the core functional components are pulverized and dried together with the above auxiliary raw materials to the same standard and set aside. The polyether-modified polysiloxane and diethylene glycol butyl ether in the core functional components, as well as the sodium pyrophosphate in the auxiliary synergistic components, do not need to be pulverized. They are placed in a drying oven and dried until the moisture content is ≤0.5% and set aside directly. Step S2, Preparation of Basic Glaze Fused Block: The mixed basic raw materials obtained in Step S1, which consist of spodumene powder, metakaolin, and flux, are placed in a high-temperature furnace. The furnace is controlled to maintain an oxidizing atmosphere to avoid a reducing atmosphere that could cause abnormal glaze color or incomplete melting. The temperature is first increased to 800-850℃ at a rate of 5-8℃ / min and held for 30-40 min. Then, the temperature is increased to 1260-1300℃ at a rate of 10-12℃ / min and held for 1.5-2 h to fully melt the mixed basic raw materials and form a uniform glassy fused block. After melting, the fused block is quickly poured into cold water for water quenching. After cooling to room temperature, it is then pulverized in a pulverizer to a particle size ≤0.1μm to obtain basic glaze fused block powder for later use. Step S3, Glaze Mixing and Dispersion: Place the basic glaze frit powder obtained in Step S2 into a high-speed mixer, add the flow modifier, color stabilizer, binder pretreated in Step S1, and the nano-hydroxyapatite, cerium oxide, and nano-silicon nitride from the core functional components, then add 0.15-0.20 times the mass of the basic glaze frit powder in deionized water, adjust the mixer speed to 400-500 r / min, and mix for 30-40 min to obtain a preliminary mixed glaze; then slowly add the colorant slurry obtained in Step S1 to the preliminary mixed glaze, and continue mixing at 400-500 r / min for 20-30 min; finally add the defoamer, the polyether-modified polysiloxane and diethylene glycol butyl ether from the core functional components, and the sodium pyrophosphate from the auxiliary synergistic components, reduce the mixer speed to 200-300 r / min, and continue mixing for 10-15 min to fully eliminate the bubbles generated during the mixing process, and obtain a uniform and fine ceramic glaze slurry; Step S4, Grinding and Refining: Place the ceramic glaze slurry obtained in Step S3 into a sand mill, using zirconia beads with a particle size of 0.5-1 mm as the grinding medium; adjust the sand mill speed to 800-1000 r / min, and grind for 60-90 min. During the grinding process, take samples every 15 min and use a particle size analyzer to check the glaze particle size to ensure that the glaze particle size is uniformly distributed between 0.05-0.5 μm; if the particle size is too large, continue to extend the grinding time until it meets the requirements; after grinding, adjust the viscosity of the ceramic glaze to between 0.8-1.2 Pa·s; after adjustment, a fine, uniform, and appropriately fluid ceramic glaze for painting is obtained; Step S5, Storage for later use: After grinding and refining the ceramic glaze and adjusting the viscosity in step S4, place it in a sealed container and store it in an environment with a temperature of 25-30℃ and a relative humidity of ≤60%. Stir for 10 minutes every 24 hours during storage to prevent the precipitation and stratification of pigments, nanoparticles and other components in the glaze, and to ensure the stability of the glaze performance.

[0016] Due to the application of the above technical solution, the present invention has the following beneficial effects: (1) Significantly improved color stability and high color fidelity: The colorant of this invention is made of cobalt oxide and iron oxide in a ratio of 1:(1-2), combined with a color stabilizer made of zirconium oxide and silicon dioxide. Combined with the synergistic color stabilizing effect of cerium oxide (rare earth oxide), nano hydroxyapatite and nano silicon nitride in the core functional components, a "quadruple color stabilizing mechanism" is formed. It can effectively inhibit the oxidation, decomposition and ion migration of the colorant during the high-temperature firing process of 1180-1250℃. The color fidelity is high, the color difference is small, there are no obvious color spots or color differences, and the painting colors are delicate and full. It can accurately reproduce the creator's color expression intention and solve the technical pain points of unstable color development and obvious color difference of existing glazes.

[0017] (2) Precise and controllable fluidity, good painting smoothness: The fluidity regulator is a 1:1 compound of sodium carboxymethyl cellulose and bentonite, combined with the synergistic effect of polyether modified polysiloxane (BYK-333) and diethylene glycol butyl ether in the core functional components, to precisely control the viscosity of the glaze between 0.8-1.2 Pa·s. This not only solves the problem of line smudging and blurred boundaries caused by the excessive fluidity of existing glazes, but also avoids the problem of brushstroke stuttering and uneven glazing caused by the insufficient fluidity. At the same time, it can be used for ultra-fine line outlining below 0.08mm, taking into account the needs of complex pattern drawing and large area coloring, greatly improving the smoothness of operation, reducing the difficulty of ceramic painting, and meeting the needs of creators of different levels.

[0018] (3) Excellent glaze performance and extremely low defect rate: The base glaze adopts an optimized ratio, and with the synergistic effect of spodumene powder and metakaolin in the auxiliary enhancement components, the expansion coefficient of the glaze can be precisely controlled, and it has strong compatibility with various ceramic bodies; the nano hydroxyapatite and nano silicon nitride in the core functional components work synergistically with the base glaze to form a "three-dimensional skeleton structure", which improves the density and hardness of the glaze, with high Mohs hardness and excellent wear resistance; the defoamer (polydimethylsiloxane ZZSIL®201-12500) and polyether modified polysiloxane work synergistically to defoam, which can completely eliminate large and small bubbles, resulting in an extremely low glaze defect rate; at the same time, the glaze layer is tightly bonded to the body, with high bonding strength, no risk of glaze peeling or cracking, which can effectively protect ceramic paintings and extend their lifespan. Through the synergistic matching of the base glaze, flux system and auxiliary enhancement components, the glaze has excellent thermal stability performance.

[0019] (4) Good environmental performance and low preparation cost: All components of this invention are lead-free and environmentally friendly, without the addition of heavy metals and harmful substances. The binder is polyvinyl alcohol 400, which has good water solubility and no toxic residues. The cerium oxide in the core functional component can adsorb and degrade the trace heavy metal residues brought in by the raw materials, resulting in low heavy metal leaching. The flux and spodumene powder work synergistically to reduce the melting temperature of the glaze and save firing energy. The sodium citrate and sodium pyrophosphate in the auxiliary enhancement components can shorten the preparation time and reduce the raw material cost. Both the core functional and auxiliary enhancement components are commercially available products and do not require custom synthesis. The overall preparation cost is significantly lower than that of existing high-end painting ceramic glazes, making it highly practical. Detailed Implementation

[0020] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. Example 1

[0021] A ceramic glaze for painting, by weight, comprises the following raw materials: 72 parts base glaze, 12 parts colorant, 3 parts flow modifier, 2 parts color stabilizer, 2 parts flux, 0.3 parts defoamer, 0.8 parts binder, 1.1 parts core functional component, and 5.3 parts auxiliary synergistic component; the core functional component is a compound of nano-hydroxyapatite, polyether-modified polysiloxane, rare earth oxide, nano-silicon nitride, and diethylene glycol butyl ether in a weight ratio of 3:1:2:2:3; the auxiliary synergistic component is a compound of sodium citrate, spodumene powder, metakaolin, and sodium pyrophosphate in a weight ratio of 0.2:2:3:0.1.

[0022] The base glaze, by weight, comprises the following raw materials: 28 parts quartz sand, 20 parts feldspar, 18 parts kaolin, 10 parts calcite, 7 parts talc, and 5 parts alumina; the colorant is a mixture of cobalt oxide and iron oxide in a 1:1 weight ratio; the flowability modifier is a mixture of sodium carboxymethyl cellulose and bentonite in a 1:1 weight ratio; the color stabilizer is a mixture of zirconium oxide and silicon dioxide in a 1:2 weight ratio; and the flux is a mixture of borax and lithium carbonate in a 2:2 weight ratio. The following components are used: 1. The defoamer is polydimethylsiloxane ZZSIL®201-12500; the binder is polyvinyl alcohol 400; the average particle size of the nano-hydroxyapatite is 10 μm; the polyether-modified polysiloxane is BYK-333; the rare earth oxide is cerium oxide with an average particle size of 20 nm; the average particle size of the nano-silicon nitride is 20 nm; the particle size of the spodumene powder is 500 mesh; and the particle size of the metakaolin is 800 mesh.

[0023] A method for preparing the aforementioned ceramic glaze for painting includes the following steps: Step S1, Raw Material Pretreatment: Select quartz sand, feldspar, kaolin, calcite, talc, and alumina respectively, remove impurities, and place them in a drying oven to dry at 105℃ for 2 hours. After drying, put each raw material into a pulverizer for pulverization, and then pass them through a 200-mesh sieve. The residue is returned to the pulverizer for re-pulverization to ensure that the particle size of each raw material is uniform and free of coarse particles. Then, mix the pulverized raw materials evenly according to the basic glaze ratio to obtain mixed basic raw materials. At the same time, spodumene powder and metakaolinite powder in the auxiliary synergistic components are added. The clay, flux, and base raw materials are mixed evenly and set aside. Cobalt oxide and iron oxide are selected and mixed evenly according to the mass ratio to obtain a composite colorant. The composite colorant is placed in a drying oven and dried at 100℃ for 1 hour. Then, the dried composite colorant is placed in a ball mill, a small amount of deionized water is added, and sodium citrate from the auxiliary synergistic component is added. The mixture is ball-milled for 30 minutes at a speed of 200 r / min and a ball-to-material ratio of 5:1. After ball milling, a colorant slurry with a solid content of 60% is obtained and set aside. The flow modifier, color stabilizer, flux, defoamer, and binder are placed in a drying oven and dried until the moisture content is ≤0.5%. Then, they are pulverized in a pulverizer until the particle size is ≤0.1μm and set aside. At the same time, the nano-hydroxyapatite, cerium oxide, and nano-silicon nitride in the core functional components are pulverized and dried together with the above auxiliary raw materials to the same standard and set aside. The polyether-modified polysiloxane and diethylene glycol butyl ether in the core functional components, as well as the sodium pyrophosphate in the auxiliary synergistic components, do not need to be pulverized. They are placed in a drying oven and dried until the moisture content is ≤0.5% and set aside directly. Step S2, Preparation of Basic Glaze Fused Block: The mixed basic raw materials obtained in Step S1, which consist of spodumene powder, metakaolin, and flux, are placed in a high-temperature furnace. The furnace is controlled to maintain an oxidizing atmosphere to avoid a reducing atmosphere that could cause abnormal glaze color or incomplete melting. The temperature is first increased to 800℃ at a rate of 5℃ / min and held for 30min. Then, the temperature is increased to 1260℃ at a rate of 10℃ / min and held for 1.5h to fully melt the mixed basic raw materials and form a uniform glassy fused block. After melting, the fused block is quickly poured into cold water for water quenching. After cooling to room temperature, it is then pulverized in a pulverizer to a particle size ≤0.1μm to obtain basic glaze fused block powder for later use. Step S3, Glaze Mixing and Dispersion: Place the basic glaze frit powder obtained in Step S2 into a high-speed mixer, add the flow modifier, color stabilizer, binder (pretreated in Step S1), and the nano-hydroxyapatite, cerium oxide, and nano-silicon nitride from the core functional components, then add 0.15 times the mass of the basic glaze frit powder in deionized water, adjust the mixer speed to 400 r / min, and mix for 30 min to obtain a preliminary mixed glaze; then slowly add the colorant slurry obtained in Step S1 to the preliminary mixed glaze, and continue mixing at 400 r / min for 20 min; finally add the defoamer, the polyether-modified polysiloxane and diethylene glycol butyl ether from the core functional components, and the sodium pyrophosphate from the auxiliary synergistic components, reduce the mixer speed to 200 r / min, and continue mixing for 10 min to fully eliminate the bubbles generated during the mixing process, and obtain a uniform and fine ceramic glaze slurry; Step S4, Grinding and Refining: Place the ceramic glaze slurry obtained in Step S3 into a sand mill, using zirconia beads with a particle size of 0.5 mm as the grinding medium; adjust the sand mill speed to 800 r / min and grind for 60 min. During the grinding process, take samples every 15 min and use a particle size analyzer to check the glaze particle size to ensure that the glaze particle size is uniformly distributed between 0.05-0.5 μm; if the particle size is too large, continue to extend the grinding time until it meets the requirements; after grinding, adjust the viscosity of the ceramic glaze to 0.8 Pa·s; after adjustment, a fine, uniform, and appropriately fluid ceramic glaze for painting is obtained; Step S5, Storage for later use: After grinding and refining the ceramic glaze and adjusting the viscosity in step S4, place it in a sealed container and store it in an environment with a temperature of 25°C and a relative humidity of ≤60%. Stir for 10 minutes every 24 hours during storage to prevent the precipitation and stratification of components such as colorants and nanoparticles in the glaze, and to ensure the stability of the glaze performance. Example 2

[0024] A ceramic glaze for painting, by weight, comprises the following raw materials: 73 parts base glaze, 13 parts colorant, 4 parts flow modifier, 2.5 parts color stabilizer, 2.3 parts flux, 0.4 parts defoamer, 1 part binder, 1.5 parts core functional component, and 6.3 parts auxiliary synergistic component; the core functional component is composed of nano-hydroxyapatite, polyether-modified polysiloxane, rare earth oxide, nano-silicon nitride, and diethylene glycol butyl ether in a weight ratio of 4:1.5:3:3:4; the auxiliary synergistic component is composed of sodium citrate, spodumene powder, metakaolin, and sodium pyrophosphate in a weight ratio of 0.3:3:4:0.15.

[0025] The base glaze, by weight, comprises the following raw materials: 29 parts quartz sand, 22 parts feldspar, 19 parts kaolin, 11 parts calcite, 8 parts talc, and 5.5 parts alumina; the colorant is a mixture of cobalt oxide and iron oxide in a weight ratio of 1:1.3; the flowability modifier is a mixture of sodium carboxymethyl cellulose and bentonite in a weight ratio of 1:1; the color stabilizer is a mixture of zirconium oxide and silicon dioxide in a weight ratio of 1:2; and the flux is a mixture of borax and lithium carbonate in a weight ratio of... The mixture is formulated in a 2:1 ratio; the defoamer is polydimethylsiloxane ZZSIL®201-12500; the binder is polyvinyl alcohol 400; the average particle size of the nano-hydroxyapatite is 30nm; the polyether-modified polysiloxane is BYK-333; the rare earth oxide is cerium oxide with an average particle size of 30nm; the average particle size of the nano-silicon nitride is 40nm; the particle size of the spodumene powder is 600 mesh; and the particle size of the metakaolin is 850 mesh.

[0026] A method for preparing the aforementioned ceramic glaze for painting includes the following steps: Step S1, Raw Material Pretreatment: Select quartz sand, feldspar, kaolin, calcite, talc, and alumina respectively, remove impurities, and place them in a drying oven to dry at 106℃ for 2.3 hours. After drying, put each raw material into a pulverizer for pulverization, and then pass them through a 200-mesh sieve. The residue is returned to the pulverizer for re-pulverization to ensure that the particle size of each raw material is uniform and free of coarse particles. Then, mix the pulverized raw materials evenly according to the basic glaze ratio to obtain mixed basic raw materials. At the same time, spodumene powder and metakaolinite powder in the auxiliary synergistic components are added. The clay, flux, and base raw materials are mixed evenly and set aside. Cobalt oxide and iron oxide are selected and mixed evenly according to the mass ratio to obtain a composite colorant. The composite colorant is placed in a drying oven and dried at 102℃ for 1.2 hours. Then, the dried composite colorant is placed in a ball mill, a small amount of deionized water is added, and sodium citrate from the auxiliary synergistic component is added. The mixture is ball-milled for 40 minutes at a speed of 230 r / min and a ball-to-material ratio of 5:1. After ball milling, a colorant slurry with a solid content of 63% is obtained and set aside. The flow modifier, color stabilizer, flux, defoamer, and binder are placed in a drying oven and dried until the moisture content is ≤0.5%. Then, they are pulverized in a pulverizer until the particle size is ≤0.1μm and set aside. At the same time, the nano-hydroxyapatite, cerium oxide, and nano-silicon nitride in the core functional components are pulverized and dried together with the above auxiliary raw materials to the same standard and set aside. The polyether-modified polysiloxane and diethylene glycol butyl ether in the core functional components, as well as the sodium pyrophosphate in the auxiliary synergistic components, do not need to be pulverized. They are placed in a drying oven and dried until the moisture content is ≤0.5% and set aside directly. Step S2, Preparation of Basic Glaze Fused Block: The mixed basic raw materials obtained in Step S1, which consist of spodumene powder, metakaolin, and flux, are placed in a high-temperature furnace. The furnace is controlled to maintain an oxidizing atmosphere to avoid a reducing atmosphere that could cause abnormal glaze color or incomplete melting. The temperature is first increased to 820℃ at a rate of 6℃ / min and held for 33min. Then, the temperature is increased to 1270℃ at a rate of 10.5℃ / min and held for 1.7h to fully melt the mixed basic raw materials and form a uniform glassy fused block. After melting, the fused block is quickly poured into cold water for water quenching. After cooling to room temperature, it is then pulverized in a pulverizer to a particle size ≤0.1μm to obtain basic glaze fused block powder for later use. Step S3, Glaze Mixing and Dispersion: The basic glaze frit powder obtained in step S2 is placed in a high-speed mixer. The flowability regulator, color stabilizer, binder, and nano-hydroxyapatite, cerium oxide, and nano-silicon nitride from the core functional components are added after the pretreatment in step S1. Then, 0.16 times the mass of the basic glaze frit powder of deionized water is added. The mixer speed is adjusted to 430 r / min, and the mixture is mixed for 33 min to obtain a preliminary mixed glaze. Then, the colorant slurry obtained in step S1 is slowly added to the preliminary mixed glaze, and the mixture is continued to be mixed at 430 r / min for 23 min. Finally, the defoamer, polyether-modified polysiloxane and diethylene glycol butyl ether from the core functional components, and sodium pyrophosphate from the auxiliary synergistic components are added. The mixer speed is reduced to 230 r / min, and the mixture is continued to be mixed for 12 min to fully eliminate the bubbles generated during the mixing process and obtain a uniform and fine ceramic glaze slurry. Step S4, Grinding and Refining: Place the ceramic glaze slurry obtained in Step S3 into a sand mill, using zirconia beads with a particle size of 0.6 mm as the grinding medium; adjust the sand mill speed to 850 r / min and grind for 70 min. During the grinding process, take samples every 15 min and use a particle size analyzer to check the glaze particle size to ensure that the glaze particle size is uniformly distributed between 0.05-0.5 μm; if the particle size is too large, continue to extend the grinding time until it meets the requirements; after grinding, adjust the viscosity of the ceramic glaze to 0.9 Pa·s; after adjustment, a fine, uniform, and appropriately fluid ceramic glaze for painting is obtained; Step S5, Storage for later use: After grinding and refining the ceramic glaze and adjusting the viscosity in step S4, place it in a sealed container and store it in an environment with a temperature of 26°C and a relative humidity of ≤60%. Stir for 10 minutes every 24 hours during storage to prevent the precipitation and stratification of components such as colorants and nanoparticles in the glaze, and to ensure the stability of the glaze performance. Example 3

[0027] A ceramic glaze for painting, by weight, comprises the following raw materials: 75 parts base glaze, 15 parts colorant, 4.5 parts flow modifier, 3 parts color stabilizer, 2.5 parts flux, 0.6 parts defoamer, 1.3 parts binder, 1.9 parts core functional component, and 8.8 parts auxiliary synergistic component; the core functional component is composed of nano-hydroxyapatite, polyether-modified polysiloxane, rare earth oxide, nano-silicon nitride, and diethylene glycol butyl ether in a weight ratio of 5:2:4:3.5:5; the auxiliary synergistic component is composed of sodium citrate, spodumene powder, metakaolin, and sodium pyrophosphate in a weight ratio of 0.35:3.5:4.5:0.2.

[0028] The base glaze, by weight, comprises the following raw materials: 30 parts quartz sand, 24 parts feldspar, 20 parts kaolin, 11.5 parts calcite, 8.5 parts talc, and 6 parts alumina; the colorant is a mixture of cobalt oxide and iron oxide in a weight ratio of 1:1.5; the flowability modifier is a mixture of sodium carboxymethyl cellulose and bentonite in a weight ratio of 1:1; the color stabilizer is a mixture of zirconium oxide and silicon dioxide in a weight ratio of 1:2; and the flux is a mixture of borax and lithium carbonate in a weight ratio of... The mixture is formulated in a 2:1 ratio; the defoamer is polydimethylsiloxane ZZSIL®201-12500; the binder is polyvinyl alcohol 400; the average particle size of the nano-hydroxyapatite is 50 nm; the polyether-modified polysiloxane is BYK-333; the rare earth oxide is cerium oxide with an average particle size of 40 nm; the average particle size of the nano-silicon nitride is 50 nm; the particle size of the spodumene powder is 650 mesh; and the particle size of the metakaolin is 900 mesh.

[0029] A method for preparing the aforementioned ceramic glaze for painting includes the following steps: Step S1, Raw Material Pretreatment: Select quartz sand, feldspar, kaolin, calcite, talc, and alumina respectively, remove impurities, and place them in a drying oven to dry at 108℃ for 2.5 hours. After drying, put each raw material into a pulverizer for pulverization, and then pass them through a 200-mesh sieve. The residue is returned to the pulverizer for re-pulverization to ensure that the particle size of each raw material is uniform and free of coarse particles. Then, mix the pulverized raw materials evenly according to the basic glaze ratio to obtain mixed basic raw materials. At the same time, spodumene powder and metakaolinite powder in the auxiliary synergistic components are added. The clay, flux, and base raw materials are mixed evenly and set aside. Cobalt oxide and iron oxide are selected and mixed evenly according to the mass ratio to obtain a composite colorant. The composite colorant is placed in a drying oven and dried at 103℃ for 1.3 hours. Then, the dried composite colorant is placed in a ball mill, a small amount of deionized water is added, and sodium citrate from the auxiliary synergistic component is added. The mixture is ball-milled for 45 minutes at a speed of 250 r / min and a ball-to-material ratio of 5:1. After ball milling, a colorant slurry with a solid content of 65% is obtained and set aside. The flow modifier, color stabilizer, flux, defoamer, and binder are placed in a drying oven and dried until the moisture content is ≤0.5%. Then, they are pulverized in a pulverizer until the particle size is ≤0.1μm and set aside. At the same time, the nano-hydroxyapatite, cerium oxide, and nano-silicon nitride in the core functional components are pulverized and dried together with the above auxiliary raw materials to the same standard and set aside. The polyether-modified polysiloxane and diethylene glycol butyl ether in the core functional components, as well as the sodium pyrophosphate in the auxiliary synergistic components, do not need to be pulverized. They are placed in a drying oven and dried until the moisture content is ≤0.5% and set aside directly. Step S2, Preparation of Basic Glaze Fused Block: The mixed basic raw materials obtained in Step S1, which consist of spodumene powder, metakaolin, and flux, are placed in a high-temperature furnace. The furnace is controlled to maintain an oxidizing atmosphere to avoid abnormal glaze color and incomplete melting caused by a reducing atmosphere. The temperature is first increased to 830℃ at a rate of 6.5℃ / min and held for 35 min. Then, the temperature is increased to 1280℃ at a rate of 11℃ / min and held for 1.8 h to fully melt the mixed basic raw materials and form a uniform glassy fused block. After melting, the fused block is quickly poured into cold water for water quenching. After cooling to room temperature, it is pulverized in a pulverizer to a particle size ≤0.1μm to obtain basic glaze fused block powder for later use. Step S3, Glaze Mixing and Dispersion: The basic glaze frit powder obtained in Step S2 is placed in a high-speed mixer. The flowability regulator, color stabilizer, binder, and nano-hydroxyapatite, cerium oxide, and nano-silicon nitride from the core functional components are added after the pretreatment in Step S1. Then, 0.18 times the mass of the basic glaze frit powder of deionized water is added. The mixer speed is adjusted to 450 r / min, and the mixture is mixed for 35 min to obtain a preliminary mixed glaze. Then, the colorant slurry obtained in Step S1 is slowly added to the preliminary mixed glaze, and the mixture is continued to be mixed at 450 r / min for 25 min. Finally, the defoamer, polyether-modified polysiloxane and diethylene glycol butyl ether from the core functional components, and sodium pyrophosphate from the auxiliary synergistic components are added. The mixer speed is reduced to 250 r / min, and the mixture is continued to be mixed for 13 min to fully eliminate the bubbles generated during the mixing process and obtain a uniform and fine ceramic glaze slurry. Step S4, Grinding and Refining: Place the ceramic glaze slurry obtained in Step S3 into a sand mill, using zirconia beads with a particle size of 0.8 mm as the grinding medium; adjust the sand mill speed to 900 r / min and grind for 75 min. During the grinding process, take samples every 15 min and use a particle size analyzer to check the glaze particle size to ensure that the glaze particle size is uniformly distributed between 0.05-0.5 μm; if the particle size is too large, continue to extend the grinding time until it meets the requirements; after grinding, adjust the viscosity of the ceramic glaze to 1 Pa·s; after adjustment, a fine, uniform, and appropriately fluid ceramic glaze for painting is obtained; Step S5, Storage for later use: After grinding and refining the ceramic glaze and adjusting the viscosity in step S4, place it in a sealed container and store it in an environment with a temperature of 28°C and a relative humidity of ≤60%. Stir for 10 minutes every 24 hours during storage to prevent the precipitation and stratification of components such as colorants and nanoparticles in the glaze, and to ensure the stability of the glaze performance. Example 4

[0030] A ceramic glaze for painting, by weight, comprises the following raw materials: 77 parts base glaze, 17 parts colorant, 5 parts flow modifier, 3.5 parts color stabilizer, 2.8 parts flux, 0.7 parts defoamer, 1.3 parts binder, 2.7 parts core functional component, and 10.9 parts auxiliary synergistic component; the core functional component is a compound of nano-hydroxyapatite, polyether-modified polysiloxane, rare earth oxide, nano-silicon nitride, and diethylene glycol butyl ether in a weight ratio of 7:2.5:5:4.5:6; the auxiliary synergistic component is a compound of sodium citrate, spodumene powder, metakaolin, and sodium pyrophosphate in a weight ratio of 0.45:4.5:5.5:0.25.

[0031] The base glaze, by weight, is composed of the following raw materials: 31 parts quartz sand, 25 parts feldspar, 21 parts kaolin, 12.5 parts calcite, 9.5 parts talc, and 6.5 parts alumina.

[0032] The colorant is a mixture of cobalt oxide and iron oxide in a mass ratio of 1:1.8; the flowability modifier is a mixture of sodium carboxymethyl cellulose and bentonite in a mass ratio of 1:1; the color stabilizer is a mixture of zirconium oxide and silicon dioxide in a mass ratio of 1:2; the flux is a mixture of borax and lithium carbonate in a mass ratio of 2:1; the defoamer is polydimethylsiloxane ZZSIL®201-12500; the binder is polyvinyl alcohol 400; the average particle size of the nano-hydroxyapatite is 70 nm; the polyether-modified polysiloxane is BYK-333; the rare earth oxide is cerium oxide with an average particle size of 50 nm; the average particle size of the nano-silicon nitride is 60 nm; the particle size of the spodumene powder is 750 mesh; and the particle size of the metakaolin is 950 mesh.

[0033] A method for preparing the aforementioned ceramic glaze for painting includes the following steps: Step S1, Raw Material Pretreatment: Select quartz sand, feldspar, kaolin, calcite, talc, and alumina respectively, remove impurities, and place them in a drying oven to dry at 109℃ for 2.8 hours. After drying, put each raw material into a pulverizer for pulverization, and then pass them through a 200-mesh sieve. The residue is returned to the pulverizer for re-pulverization to ensure that the particle size of each raw material is uniform and free of coarse particles. Then, mix the pulverized raw materials evenly according to the basic glaze ratio to obtain mixed basic raw materials. At the same time, spodumene powder and metakaolinite powder in the auxiliary synergistic components are added. The clay, flux, and base raw materials are mixed evenly and set aside. Cobalt oxide and iron oxide are selected and mixed evenly according to the mass ratio to obtain a composite colorant. The composite colorant is placed in a drying oven and dried at 104℃ for 1.4h. Then, the dried composite colorant is placed in a ball mill, a small amount of deionized water is added, and sodium citrate from the auxiliary synergistic component is added. The mixture is ball-milled for 55min at a speed of 280r / min and a ball-to-material ratio of 5:1. After ball milling, a colorant slurry with a solid content of 68% is obtained and set aside. The flow modifier, color stabilizer, flux, defoamer, and binder are placed in a drying oven and dried until the moisture content is ≤0.5%. Then, they are pulverized in a pulverizer until the particle size is ≤0.1μm and set aside. At the same time, the nano-hydroxyapatite, cerium oxide, and nano-silicon nitride in the core functional components are pulverized and dried together with the above auxiliary raw materials to the same standard and set aside. The polyether-modified polysiloxane and diethylene glycol butyl ether in the core functional components, as well as the sodium pyrophosphate in the auxiliary synergistic components, do not need to be pulverized. They are placed in a drying oven and dried until the moisture content is ≤0.5% and set aside directly. Step S2, Preparation of Basic Glaze Fused Block: The mixed basic raw materials obtained in Step S1, which consist of spodumene powder, metakaolin, and flux, are placed in a high-temperature furnace. The furnace is controlled to maintain an oxidizing atmosphere to avoid abnormal glaze color and incomplete melting caused by a reducing atmosphere. The temperature is first increased to 840℃ at a rate of 7.5℃ / min and held for 38 min. Then, the temperature is increased to 1290℃ at a rate of 11.5℃ / min and held for 1.9 h to fully melt the mixed basic raw materials and form a uniform glassy fused block. After melting, the fused block is quickly poured into cold water for water quenching. After cooling to room temperature, it is pulverized in a pulverizer to a particle size ≤0.1μm to obtain basic glaze fused block powder for later use. Step S3, Glaze Mixing and Dispersion: The basic glaze frit powder obtained in Step S2 is placed in a high-speed mixer. The flowability regulator, color stabilizer, binder, and nano-hydroxyapatite, cerium oxide, and nano-silicon nitride from the core functional components are added after the pretreatment in Step S1. Then, 0.19 times the mass of the basic glaze frit powder of deionized water is added. The mixer speed is adjusted to 490 r / min, and the mixture is mixed for 38 min to obtain a preliminary mixed glaze. Then, the colorant slurry obtained in Step S1 is slowly added to the preliminary mixed glaze, and the mixture is continued to be mixed at 480 r / min for 28 min. Finally, the defoamer, polyether-modified polysiloxane and diethylene glycol butyl ether from the core functional components, and sodium pyrophosphate from the auxiliary synergistic components are added. The mixer speed is reduced to 280 r / min, and the mixture is continued to be mixed for 14 min to fully eliminate the bubbles generated during the mixing process and obtain a uniform and fine ceramic glaze slurry. Step S4, Grinding and Refining: Place the ceramic glaze slurry obtained in Step S3 into a sand mill, using zirconia beads with a particle size of 0.9 mm as the grinding medium; adjust the sand mill speed to 950 r / min and grind for 85 min. During the grinding process, take samples every 15 min and use a particle size analyzer to check the glaze particle size to ensure that the glaze particle size is uniformly distributed between 0.05-0.5 μm; if the particle size is too large, continue to extend the grinding time until it meets the requirements; after grinding, adjust the viscosity of the ceramic glaze to 1.1 Pa·s; after adjustment, a fine, uniform, and appropriately fluid ceramic glaze for painting is obtained; Step S5, Storage for later use: After grinding and refining the ceramic glaze and adjusting the viscosity in step S4, place it in a sealed container and store it in an environment with a temperature of 29°C and a relative humidity of ≤60%. Stir for 10 minutes every 24 hours during storage to prevent the precipitation and stratification of components such as colorants and nanoparticles in the glaze, and to ensure the stability of the glaze performance. Example 5

[0034] A ceramic glaze for painting, by weight, comprises the following raw materials: 78 parts base glaze, 18 parts colorant, 6 parts flow modifier, 4 parts color stabilizer, 3 parts flux, 0.8 parts defoamer, 1.5 parts binder, 2.9 parts core functional component, and 11.9 parts auxiliary synergistic component; the core functional component is a compound of nano-hydroxyapatite, polyether-modified polysiloxane, rare earth oxide, nano-silicon nitride, and diethylene glycol butyl ether in a weight ratio of 8:3:6:5:7; the auxiliary synergistic component is a compound of sodium citrate, spodumene powder, metakaolin, and sodium pyrophosphate in a weight ratio of 0.5:5:6:0.3.

[0035] The base glaze, by weight, comprises the following raw materials: 32 parts quartz sand, 26 parts feldspar, 22 parts kaolin, 13 parts calcite, 10 parts talc, and 7 parts alumina; the colorant is a mixture of cobalt oxide and iron oxide in a weight ratio of 1:2; the flowability modifier is a mixture of sodium carboxymethyl cellulose and bentonite in a weight ratio of 1:1; the color stabilizer is a mixture of zirconium oxide and silicon dioxide in a weight ratio of 1:2; and the flux is a mixture of borax and lithium carbonate in a weight ratio of 2:1. 1. The compound is composed of the following: the defoamer is polydimethylsiloxane ZZSIL®201-12500; the binder is polyvinyl alcohol 400; the average particle size of the nano-hydroxyapatite is 80nm; the polyether-modified polysiloxane is BYK-333; the rare earth oxide is cerium oxide with an average particle size of 60nm; the average particle size of the nano-silicon nitride is 70nm; the particle size of the spodumene powder is 800 mesh; and the particle size of the metakaolin is 1000 mesh.

[0036] A method for preparing the aforementioned ceramic glaze for painting includes the following steps: Step S1, Raw Material Pretreatment: Select quartz sand, feldspar, kaolin, calcite, talc, and alumina respectively, remove impurities, and place them in a drying oven to dry at 110℃ for 3 hours. After drying, put each raw material into a pulverizer for pulverization, and then pass them through a 200-mesh sieve. The residue on the sieve is returned to the pulverizer for re-pulverization to ensure that the particle size of each raw material is uniform and free of coarse particles. Then, mix the pulverized raw materials evenly according to the basic glaze ratio to obtain mixed basic raw materials. At the same time, spodumene powder and metakaolin from the auxiliary synergistic components are added. The flux and the base raw materials are mixed evenly and set aside. Cobalt oxide and iron oxide are selected and mixed evenly according to the mass ratio to obtain a composite colorant. The composite colorant is placed in a drying oven and dried at 105℃ for 1.5h. Then, the dried composite colorant is placed in a ball mill, a small amount of deionized water is added, and sodium citrate from the auxiliary synergistic component is added. The ball mill is milled for 60min at a speed of 300r / min and a ball-to-material ratio of 5:1. After ball milling, a colorant slurry with a solid content of 70% is obtained and set aside. The flow modifier, color stabilizer, flux, defoamer, and binder are placed in a drying oven and dried until the moisture content is ≤0.5%. Then, they are pulverized in a pulverizer until the particle size is ≤0.1μm and set aside. At the same time, the nano-hydroxyapatite, cerium oxide, and nano-silicon nitride in the core functional components are pulverized and dried together with the above auxiliary raw materials to the same standard and set aside. The polyether-modified polysiloxane and diethylene glycol butyl ether in the core functional components, as well as the sodium pyrophosphate in the auxiliary synergistic components, do not need to be pulverized. They are placed in a drying oven and dried until the moisture content is ≤0.5% and set aside directly. Step S2, Preparation of Basic Glaze Fused Block: The mixed basic raw materials obtained in Step S1, which consist of spodumene powder, metakaolin, and flux, are placed in a high-temperature furnace. The furnace is controlled to maintain an oxidizing atmosphere to avoid a reducing atmosphere that could cause abnormal glaze color or incomplete melting. The temperature is first increased to 850℃ at a rate of 8℃ / min and held for 40min. Then, the temperature is increased to 1300℃ at a rate of 12℃ / min and held for 2h to fully melt the mixed basic raw materials and form a uniform glassy fused block. After melting, the fused block is quickly poured into cold water for water quenching. After cooling to room temperature, it is then pulverized in a pulverizer to a particle size ≤0.1μm to obtain basic glaze fused block powder for later use. Step S3, Glaze Mixing and Dispersion: Place the basic glaze frit powder obtained in Step S2 into a high-speed mixer, add the flow modifier, color stabilizer, binder pretreated in Step S1, and the nano-hydroxyapatite, cerium oxide, and nano-silicon nitride from the core functional components, then add 0.20 times the mass of the basic glaze frit powder in deionized water, adjust the mixer speed to 500 r / min, and mix for 40 min to obtain a preliminary mixed glaze; then slowly add the colorant slurry obtained in Step S1 to the preliminary mixed glaze, and continue mixing at 500 r / min for 30 min; finally add the defoamer, the polyether-modified polysiloxane and diethylene glycol butyl ether from the core functional components, and the sodium pyrophosphate from the auxiliary synergistic components, reduce the mixer speed to 300 r / min, and continue mixing for 15 min to fully eliminate the bubbles generated during the mixing process, and obtain a uniform and fine ceramic glaze slurry; Step S4, Grinding and Refining: Place the ceramic glaze slurry obtained in step S3 into a sand mill, using 1mm zirconia beads as the grinding medium; adjust the sand mill speed to 1000r / min and grind for 90min. During the grinding process, take samples every 15min and use a particle size analyzer to check the glaze particle size to ensure that the glaze particle size is uniformly distributed between 0.05-0.5μm; if the particle size is too large, continue to extend the grinding time until it meets the requirements; after grinding, adjust the viscosity of the ceramic glaze to 1.2Pa·s; after adjustment, a fine, uniform, and appropriately fluid ceramic glaze for painting is obtained. Step S5, Storage for later use: After grinding and refining the ceramic glaze and adjusting the viscosity in step S4, place it in a sealed container and store it in an environment with a temperature of 30°C and a relative humidity of ≤60%. Stir for 10 minutes every 24 hours during storage to prevent the precipitation and stratification of components such as colorants and nanoparticles in the glaze, and to ensure the stability of the glaze performance.

[0037] Comparative Example 1 A ceramic glaze for painting and its preparation method are basically the same as those in Example 5, except that an equal amount of core functional components are used instead of auxiliary synergistic components.

[0038] Comparative Example 2 A ceramic glaze for painting and its preparation method are basically the same as those in Example 5, except that an equal amount of auxiliary synergistic components are used instead of the core functional components.

[0039] Comparative Example 3 A ceramic glaze for painting and its preparation method are basically the same as those in Example 5, except that an equal amount of nano-hydroxyapatite is used instead of rare earth oxides.

[0040] Comparative Example 4 A ceramic glaze for painting and its preparation method are basically the same as those in Example 5, except that an equal amount of rare earth oxides are used instead of nano-hydroxyapatite.

[0041] The ceramic glazes prepared in Example 5 and Comparative Examples 1-4 were used to paint on the surface of white porcelain blanks of the same size (drawing the same pattern, with a line width of 0.5 mm and a painted area of ​​5 cm × 5 cm). They were then fired under the following conditions: heating rate 8℃ / min, firing temperature 1220℃, holding time 1 h, cooling rate 5℃ / min. After cooling to room temperature, the performance of the fired ceramic painted samples was tested. The test results are shown in Table 1. The test methods are as follows: (1) Color reproduction: The color difference ΔE of the pigment before and after firing was measured by a colorimeter. Color reproduction = (1-ΔE / ΔE0)×100%, where ΔE0 is the color difference of the standard pigment before and after firing (the average value of 5 tests was taken). (2) Drawing fluency: Use a brush (wolf hair, brush tip diameter 0.1mm) to outline the lines and observe the brushstrokes and the lines are blurred; no brushstrokes or blurring is excellent; slight brushstrokes or blurring is good; the rest are unqualified.

[0042] (3) Glaze defect rate: The glaze surface was observed using a microscope (100x magnification), and the number of samples with defects such as bubbles, cracks and glaze peeling was counted. Defect rate = (number of defective samples / total number of samples) × 100% (total number of samples 50).

[0043] (4) Thermal stability test: Immediately immerse the fired ceramic painting sample in 20°C water for rapid cooling and observe whether the glaze cracks or peels off.

[0044] Table 1. Test results of ceramic glaze performance for painting project Color reproduction Drawing fluency Glaze defect rate Thermal stability (after rapid cooling) unit % — % — Example 5 99.1 excellent 0.0 No cracks or peeling Comparative Example 1 90.2 good 8.0 Slight cracks Comparative Example 2 91.5 good 6.0 slight peeling Comparative Example 3 93.3 good 4.0 No cracks, slight glaze peeling Comparative Example 4 94.0 good 4.0 No cracks, slight glaze peeling As shown in Table 1, the ceramic glaze for painting prepared in Example 5 exhibits the best overall performance, with a color reproduction rate of 99.1%, excellent painting smoothness, and a glaze defect rate of 0.0%. Furthermore, it showed no cracking or peeling after rapid cooling. In contrast, Comparative Examples 1-4, due to the absence of auxiliary synergistic components, core functional components, or improper proportions of core components, showed significantly inferior performance compared to Example 5. Their color reproduction rates were all below 95%, painting smoothness was only good, glaze defect rates were significantly increased, and thermal stability also decreased to varying degrees (slight cracking, slight peeling, or slight glaze loss). This clearly demonstrates that the rational combination of core functional components and auxiliary synergistic components, as well as the scientific ratio of each core component, are crucial for improving the overall performance of ceramic glazes for painting.

[0045] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A ceramic glaze for painting, characterized in that, By weight, its raw material composition includes: 72-78 parts of base glaze, 12-18 parts of colorant, 3-6 parts of flow modifier, 2-4 parts of color stabilizer, 2-3 parts of flux, 0.3-0.8 parts of defoamer, 0.8-1.5 parts of binder, 1.1-2.9 parts of core functional component, and 5.3-11.9 parts of auxiliary synergistic component; the core functional component is compounded from nano hydroxyapatite, polyether modified polysiloxane, rare earth oxide, nano silicon nitride, and diethylene glycol butyl ether in a weight ratio of (3-8):(1-3):(2-6):(2-5):(3-7); the auxiliary synergistic component is compounded from sodium citrate, spodumene powder, metakaolin, and sodium pyrophosphate in a weight ratio of (0.2-0.5):(2-5):(3-6):(0.1-0.3).

2. The ceramic glaze for painting according to claim 1, characterized in that, The base glaze, by weight, is composed of the following raw materials: 28-32 parts quartz sand, 20-26 parts feldspar, 18-22 parts kaolin, 10-13 parts calcite, 7-10 parts talc, and 5-7 parts alumina.

3. The ceramic glaze for painting according to claim 1, characterized in that, The colorant is a mixture of cobalt oxide and iron oxide in a mass ratio of 1:(1-2); the flowability modifier is a mixture of sodium carboxymethyl cellulose and bentonite in a mass ratio of 1:

1.

4. The ceramic glaze for painting according to claim 1, characterized in that, The color stabilizer is a mixture of zirconium oxide and silicon dioxide in a mass ratio of 1:2; the flux is a mixture of borax and lithium carbonate in a mass ratio of 2:

1.

5. The ceramic glaze for painting according to claim 1, characterized in that, The defoamer is polydimethylsiloxane ZZSIL®201-12500; the binder is polyvinyl alcohol 400.

6. The ceramic glaze for painting according to claim 1, characterized in that, The nano-hydroxyapatite has an average particle size of 10-80 nm; the polyether-modified polysiloxane is of type BYK-333; the rare earth oxide is cerium oxide with an average particle size of 20-60 nm; the nano-silicon nitride has an average particle size of 20-70 nm; the spodumene powder has a particle size of 500-800 mesh; and the metakaolin has a particle size of 800-1000 mesh.

7. A method for preparing a ceramic glaze for painting according to any one of claims 1-6, characterized in that, Includes the following steps: Step S1, Raw Material Pretreatment: Select quartz sand, feldspar, kaolin, calcite, talc, and alumina respectively, remove impurities, and place them in a drying oven at 105-110℃ for 2-3 hours. After drying, put each raw material into a pulverizer for crushing, and then pass them through a 200-mesh sieve. The residue is returned to the pulverizer for re-crushing to ensure that the particle size of each raw material is uniform and free of coarse particles. Then, mix the crushed raw materials evenly according to the basic glaze ratio to obtain mixed basic raw materials. At the same time, add the spodumene powder, metakaolin, flux, and other auxiliary synergistic components to the mixture. Mix the basic raw materials together until homogeneous and set aside. Select cobalt oxide and iron oxide, and mix them evenly according to the mass ratio to obtain a composite colorant. Place the composite colorant in a drying oven and dry it at 100-105℃ for 1-1.5 hours. Then, put the dried composite colorant into a ball mill, add a small amount of deionized water, and add sodium citrate from the auxiliary synergistic component. Ball mill for 30-60 minutes at a speed of 200-300 r / min and a ball-to-material ratio of 5:

1. After ball milling, obtain a colorant slurry with a solid content of 60%-70% and set aside. The flow modifier, color stabilizer, flux, defoamer, and binder are placed in a drying oven and dried until the moisture content is ≤0.5%. Then, they are pulverized in a pulverizer until the particle size is ≤0.1μm and set aside. At the same time, the nano-hydroxyapatite, cerium oxide, and nano-silicon nitride in the core functional components are pulverized and dried together with the above auxiliary raw materials to the same standard and set aside. The polyether-modified polysiloxane and diethylene glycol butyl ether in the core functional components, as well as the sodium pyrophosphate in the auxiliary synergistic components, do not need to be pulverized. They are placed in a drying oven and dried until the moisture content is ≤0.5% and set aside directly. Step S2, Preparation of Basic Glaze Fused Block: The mixed basic raw materials obtained in Step S1, which consist of spodumene powder, metakaolin, and flux, are placed in a high-temperature furnace. The furnace is controlled to maintain an oxidizing atmosphere to avoid a reducing atmosphere that could cause abnormal glaze color or incomplete melting. The temperature is first increased to 800-850℃ at a rate of 5-8℃ / min and held for 30-40 min. Then, the temperature is increased to 1260-1300℃ at a rate of 10-12℃ / min and held for 1.5-2 h to fully melt the mixed basic raw materials and form a uniform glassy fused block. After melting, the fused block is quickly poured into cold water for water quenching. After cooling to room temperature, it is then pulverized in a pulverizer to a particle size ≤0.1μm to obtain basic glaze fused block powder for later use. Step S3, Glaze Mixing and Dispersion: Place the basic glaze frit powder obtained in Step S2 into a high-speed mixer, add the flow modifier, color stabilizer, binder pretreated in Step S1, and the nano-hydroxyapatite, cerium oxide, and nano-silicon nitride from the core functional components, then add 0.15-0.20 times the mass of the basic glaze frit powder in deionized water, adjust the mixer speed to 400-500 r / min, and mix for 30-40 min to obtain a preliminary mixed glaze; then slowly add the colorant slurry obtained in Step S1 to the preliminary mixed glaze, and continue mixing at 400-500 r / min for 20-30 min; finally add the defoamer, the polyether-modified polysiloxane and diethylene glycol butyl ether from the core functional components, and the sodium pyrophosphate from the auxiliary synergistic components, reduce the mixer speed to 200-300 r / min, and continue mixing for 10-15 min to fully eliminate the bubbles generated during the mixing process, and obtain a uniform and fine ceramic glaze slurry; Step S4, Grinding and Refining: Place the ceramic glaze slurry obtained in Step S3 into a sand mill, using zirconia beads with a particle size of 0.5-1 mm as the grinding medium; adjust the sand mill speed to 800-1000 r / min, and grind for 60-90 min. During the grinding process, take samples every 15 min and use a particle size analyzer to check the glaze particle size to ensure that the glaze particle size is uniformly distributed between 0.05-0.5 μm; if the particle size is too large, continue to extend the grinding time until it meets the requirements; after grinding, adjust the viscosity of the ceramic glaze to between 0.8-1.2 Pa·s; after adjustment, a fine, uniform, and appropriately fluid ceramic glaze for painting is obtained; Step S5, Storage for later use: After grinding and refining the ceramic glaze and adjusting the viscosity in step S4, place it in a sealed container and store it in an environment with a temperature of 25-30℃ and a relative humidity of ≤60%. Stir for 10 minutes every 24 hours during storage to prevent the precipitation and stratification of pigments, nanoparticles and other components in the glaze, and to ensure the stability of the glaze performance.