An antibacterial ceramic glaze and its preparation method
By introducing in-situ crystallized antibacterial components and core-shell structured antibacterial agents into ceramic glazes, combined with double-layer glazing and segmented firing processes, the problem of unstable antibacterial effect of antibacterial ceramic glazes during high-temperature sintering was solved, achieving long-term stability and high gloss of antibacterial ceramic products.
Patent Information
- Application Number
- CN202610654626.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-05-13
- Publication Date
- 2026-06-30
AI Technical Summary
Existing antibacterial ceramic glazes are prone to oxidation, deactivation, and aggregation of antibacterial active ions during high-temperature sintering, resulting in unstable antibacterial effects, poor durability, and poor compatibility between antibacterial components and glaze surface, which easily leads to defects such as cracking and glaze peeling, making it difficult to meet the needs of high-end ceramic products.
A composite antibacterial system combining in-situ crystallized antibacterial components with core-shell structured antibacterial agents is adopted. By precipitating Bi2O3, ZnO, and Ag3PO4 composite antibacterial crystal phases in the glass phase of the glaze, and loading antibacterial active ions onto an inorganic carrier and coating the shell layer, combined with double-layer glazing and segmented firing processes, the antibacterial phase is uniformly dispersed and tightly bonded to the glaze.
It achieves stable and durable antibacterial effects, avoids the volatilization and aggregation of antibacterial agents, ensures the gloss and hardness of the glaze, and meets the requirements for use in high-end ceramic products.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of ceramic materials technology, and more particularly to an antibacterial ceramic glaze and its preparation method. Background Technology
[0002] Ceramic products, due to their high-temperature resistance, corrosion resistance, ease of cleaning, and non-toxicity, are widely used in various fields such as daily-use ceramics and sanitary ceramics, making them an indispensable material in people's production and daily life. With increasing health awareness, higher demands are being placed on the antibacterial properties of ceramic products. Antibacterial ceramic glazes have emerged to address this need. By adding antibacterial components to the glaze, the ceramic surface gains the ability to inhibit or kill bacteria, fungi, and other microorganisms, effectively reducing the hygiene risks caused by microbial growth and protecting human health.
[0003] In existing technologies, the antibacterial function of antibacterial ceramic glazes is mainly achieved by adding a single antibacterial agent. Among them, silver-based antibacterial agents have outstanding antibacterial effects, while zinc-based and bismuth-based antibacterial agents have the advantages of high safety and low cost. Some technologies simply physically blend two or more antibacterial components into the base glaze to enhance the antibacterial effect. Meanwhile, to improve the dispersibility of antibacterial agents, some solutions use supported antibacterial agents such as silver-loaded zirconium phosphate, which load antibacterial active ions onto a carrier to reduce the aggregation of antibacterial agents.
[0004] However, single antibacterial systems or simple blends of antibacterial components are prone to problems such as oxidation and deactivation of antibacterial active ions and agglomeration during the high-temperature sintering of ceramics, resulting in unstable antibacterial effects and poor durability. Loaded antibacterial agents lack an effective protective structure, are easily decomposed at high temperatures, and antibacterial active ions are easily dissolved, which not only affects the long-term antibacterial effect but may also damage the glaze's gloss, hardness, and other properties. In addition, the compatibility between antibacterial components and the base glaze matrix is poor, which can easily lead to defects such as cracking and glaze peeling on the glaze surface. It is difficult to achieve both antibacterial performance and comprehensive glaze performance, and thus cannot meet the needs of high-end ceramic products. Summary of the Invention
[0005] To address the aforementioned problems in the prior art, this invention provides an antibacterial ceramic glaze and its preparation method.
[0006] The objective of this invention can be achieved through the following technical solutions: In a first aspect, the present invention provides an antibacterial ceramic glaze, comprising a basic glaze matrix and a composite antibacterial system; the composite antibacterial system comprises an in-situ crystallized antibacterial component and a core-shell structured antibacterial agent; the in-situ crystallized antibacterial component comprises a bismuth source, a zinc source and a silver source, which, during the high-temperature sintering and cooling process of ceramics, precipitates in situ a composite antibacterial crystalline phase containing bismuth, zinc and silver from the glassy phase of the glaze; the core-shell structured antibacterial agent comprises an inorganic carrier core, antibacterial active ions loaded on the core and a shell layer covering the core.
[0007] Preferably, the inorganic carrier core is nano-zirconium phosphate; the antibacterial active ions include Ag. + Zn 2+ or Cu 2+ .
[0008] Preferably, the shell is a silicon dioxide shell or a carbon coating layer.
[0009] Preferably, the base glaze matrix comprises, by weight: 25-35 parts potassium feldspar, 20-30 parts quartz, 5-10 parts kaolin, 8-15 parts calcite, 5-10 parts wollastonite, 2-5 parts zinc oxide, and 5-10 parts phosphorus-containing frit.
[0010] Preferably, the total amount of the bismuth source, zinc source and silver source added is 3-8% of the total weight of the base glaze matrix.
[0011] Preferably, the amount of the core-shell structure antibacterial agent added is 1-5% of the total weight of the base glaze matrix.
[0012] Secondly, the present invention provides a method for preparing the above-mentioned antibacterial ceramic glaze, comprising the following steps: (1) The carrier material is pre-calcined and activated, and metal ions are loaded onto the surface of the carrier material by co-precipitation. Then, a shell layer is coated on the surface of the carrier material loaded with metal ions by sol-gel method. The coated product is stabilized at 500-600℃ for 1-2 hours in an inert atmosphere to obtain a core-shell structured antibacterial agent. (2) The basic glaze raw materials, bismuth source, zinc source, silver source and the core-shell structure antibacterial agent prepared in step (1) are mixed and ball-milled to prepare glaze slurry; (3) Apply the glaze slurry prepared in step (2) to the surface of the ceramic body; (4) The glazed ceramic body is fired in sections to obtain antibacterial ceramic products.
[0013] Preferably, in step (3), the glaze is applied in a double-layer glazing process, which includes applying a base glaze first and then a top glaze.
[0014] Preferably, in step (4), the segmented firing process includes: the first segment is heated from room temperature to 600°C at a rate of 3-5°C / min; the second segment is heated to 1150°C at a rate of 5-8°C / min; the third segment is heated to 1280°C at a rate of 2-3°C / min, and held at 1280°C for 20-40 minutes.
[0015] Thirdly, the present invention provides an antibacterial ceramic product, the surface of which is covered with the above-mentioned antibacterial ceramic glaze.
[0016] The beneficial effects of this invention are as follows: (1) This invention employs a composite antibacterial system combining in-situ crystallized antibacterial components and core-shell structured antibacterial agents. During the high-temperature sintering and cooling process, the in-situ crystallized antibacterial components precipitate a composite antibacterial crystalline phase of Bi2O3, ZnO, and Ag3PO4 from the glass phase of the glaze, achieving uniform dispersion of the antibacterial phase and tight bonding with the glaze lattice, thus avoiding the volatilization and agglomeration problems of externally added antibacterial agents at high temperatures. The core-shell structured antibacterial agent, through the loading of antibacterial active ions on an inorganic carrier and the protection of the shell layer, can prevent the antibacterial ions from being oxidized and deactivated at high temperatures. The synergistic effect of the two solves the pain points of unstable antibacterial effect and poor durability in the prior art.
[0017] (2) The shell structure can effectively improve the compatibility between antibacterial agents and basic glaze matrix. The in-situ crystallized antibacterial crystal phase has strong bonding force with the glaze, avoiding problems such as glaze cracking, glaze peeling and gloss reduction caused by the aggregation of antibacterial components. It ensures that the glaze has both excellent antibacterial properties and high temperature resistance, corrosion resistance and high hardness glaze characteristics, meeting the requirements of high-end ceramic products. Detailed Implementation
[0018] To further illustrate the technical means and effects of the present invention in achieving the intended purpose, the following detailed description of the specific implementation methods, structures, features and effects of the present invention, in conjunction with preferred embodiments, is provided below.
[0019] Example 1 1. Preparation of core-shell structured antibacterial agents Take 10g of nano-zirconium phosphate and pre-calcine it in a muffle furnace at 450℃ for 2 hours, then allow it to cool naturally. Disperse the activated zirconium phosphate in 200mL of deionized water, add a mixed solution of silver nitrate and zinc nitrate, and let Ag... + With Zn 2+ The molar ratio was 1:2, and the total metal ion concentration was 0.05 mol / L. The pH was adjusted to 7.5 with 0.1 mol / L NaOH solution, and the mixture was stirred and loaded in a 50℃ water bath for 2 hours. After centrifugation, the mixture was washed three times with deionized water and dried at 60℃ for 12 hours.
[0020] The above-mentioned ion-loaded powder was dispersed in 200 mL of an ethanol-water mixture (volume ratio 4:1), and 2 mL of tetraethyl orthosilicate and 1 mL of 25 wt% ammonia solution were added. The mixture was stirred at room temperature for 4 hours to hydrolyze and coat the powder. After centrifugation, the powder was washed with ethanol and dried at 80 °C. The dried powder was then placed in a tube furnace and heated to 550 °C at a rate of 5 °C / min under a nitrogen atmosphere, held at that temperature for 1.5 hours, and allowed to cool naturally to obtain a core-shell structured antibacterial agent coated with a SiO2 shell.
[0021] 2. Preparation of the base glaze matrix Take the following raw materials by weight: 30 parts potassium feldspar, 25 parts quartz, 8 parts kaolin, 12 parts calcite, 8 parts wollastonite, 4 parts zinc oxide, and 9 parts phosphorus-containing frit. Mix the above raw materials evenly, place them in a ball mill, add an appropriate amount of water (material:water:ball = 1:0.8:1.5), and ball mill at 300 r / min for 4 hours. Pass the mixture through a 250 mesh sieve to obtain a basic glaze slurry with a solid content of 65 wt%. The obtained basic glaze slurry is for later use.
[0022] 3. Preparation of the base glaze slurry Take the above-mentioned basic glaze slurry equivalent to 70 parts dry basis, add 3 parts bismuth source sodium bismuthate, 2 parts zinc source zinc oxide, and 1 part silver source silver nitrate, ball mill at 200 r / min for 1 hour, adjust the solid content to 60 wt%, and obtain the bottom glaze slurry.
[0023] 4. Preparation of the surface glaze slurry Take the remaining base glaze slurry equivalent to 30 parts of dry basis, add 4 parts of the core-shell structure antibacterial agent prepared in step 1 and 3 parts of nano-zirconia (average particle size 60nm), ball mill at 200r / min for 1 hour, adjust the solid content to 55wt%, and obtain the surface glaze slurry.
[0024] 5. Glazing and firing A daily-use ceramic body (water absorption rate of approximately 18%) is selected. A base glaze is first applied using a spray glazing method, with the glaze thickness controlled at 0.4 mm (wet glaze), and dried at room temperature for 2 hours. Then, a top glaze is applied on the surface of the base glaze, with the thickness controlled at 0.15 mm, and dried at room temperature for 4 hours.
[0025] The glazed body is placed in an electric furnace and sintered according to the following segmented firing process: First section: Heating from room temperature to 600℃ at a rate of 4℃ / min; Second stage: Increase the temperature to 1150℃ at a rate of 6℃ / min; The third stage: the temperature is increased to 1280℃ at a rate of 2.5℃ / min, and held at 1280℃ for 30 minutes; Cooling: Allow the furnace to cool naturally to room temperature.
[0026] Example 2 1. Preparation of core-shell structured antibacterial agents Same as Example 1.
[0027] 2. Preparation of the base glaze matrix Same as Example 1.
[0028] 3. Preparation of the base glaze slurry Take the above-mentioned basic glaze slurry equivalent to 70 parts dry basis, add 4 parts bismuth source sodium bismuthate, 3 parts zinc source zinc oxide, and 1 part silver source silver nitrate, and ball mill at 200 r / min for 1 hour to adjust the solid content to 60 wt% to obtain the bottom glaze slurry.
[0029] 4. Preparation of the surface glaze slurry Take the remaining base glaze slurry equivalent to 30 parts of dry basis, add 4 parts of the core-shell structure antibacterial agent prepared in step 1 and 3 parts of nano-zirconia (average particle size 60nm), ball mill at 200r / min for 1 hour, adjust the solid content to 55wt%, and obtain the surface glaze slurry.
[0030] 5. Glazing and firing Same as Example 1.
[0031] Example 3 1. Preparation of core-shell structured antibacterial agents Same as Example 1.
[0032] 2. Preparation of the base glaze matrix Same as Example 1.
[0033] 3. Preparation of the base glaze slurry Take the above-mentioned basic glaze slurry equivalent to 70 parts dry basis, add 5 parts bismuth source sodium bismuthate, 3 parts zinc source zinc oxide, and 2 parts silver source silver nitrate, ball mill at 200 r / min for 1 hour, adjust the solid content to 60 wt%, and obtain the bottom glaze slurry.
[0034] 4. Preparation of the surface glaze slurry Take the remaining base glaze slurry equivalent to 30 parts of dry basis, add 4 parts of the core-shell structure antibacterial agent prepared in step 1 and 3 parts of nano-zirconia (average particle size 60nm), ball mill at 200r / min for 1 hour, adjust the solid content to 55wt%, and obtain the surface glaze slurry.
[0035] 5. Glazing and firing Same as Example 1.
[0036] Example 4 1. Preparation of core-shell structured antibacterial agents Same as Example 1.
[0037] 2. Preparation of the base glaze matrix Same as Example 1.
[0038] 3. Preparation of the base glaze slurry Take the above-mentioned basic glaze slurry equivalent to 70 parts dry basis, add 3 parts bismuth source sodium bismuthate, 2.5 parts zinc source zinc oxide, and 0.5 parts silver source silver nitrate, and ball mill at 200 r / min for 1 hour to adjust the solid content to 60 wt% to obtain the bottom glaze slurry.
[0039] 4. Preparation of the surface glaze slurry Take the remaining base glaze slurry equivalent to 30 parts of dry basis, add 4 parts of the core-shell structure antibacterial agent prepared in step 1 and 3 parts of nano-zirconia (average particle size 60nm), ball mill at 200r / min for 1 hour, adjust the solid content to 55wt%, and obtain the surface glaze slurry.
[0040] 5. Glazing and firing Same as Example 1.
[0041] Example 5 1. Preparation of core-shell structured antibacterial agents Same as Example 1.
[0042] 2. Preparation of the base glaze matrix Same as Example 1.
[0043] 3. Preparation of the base glaze slurry Take the above-mentioned basic glaze slurry equivalent to 70 parts dry basis, add 5 parts bismuth source sodium bismuthate, 4 parts zinc source zinc oxide, and 1 part silver source silver nitrate, ball mill at 200 r / min for 1 hour, adjust the solid content to 60 wt%, and obtain the bottom glaze slurry.
[0044] 4. Preparation of the surface glaze slurry Take the remaining base glaze slurry equivalent to 30 parts of dry basis, add 4 parts of the core-shell structure antibacterial agent prepared in step 1 and 3 parts of nano-zirconia (average particle size 60nm), ball mill at 200r / min for 1 hour, adjust the solid content to 55wt%, and obtain the surface glaze slurry.
[0045] 5. Glazing and firing Same as Example 1.
[0046] Example 6 1. Preparation of core-shell structured antibacterial agents Same as Example 1.
[0047] 2. Preparation of the base glaze matrix Same as Example 1.
[0048] 3. Preparation of the base glaze slurry Take the above-mentioned basic glaze slurry equivalent to 70 parts dry basis, add 4 parts bismuth source sodium bismuthate, 3 parts zinc source zinc oxide, and 1.5 parts silver source silver nitrate, ball mill at 200 r / min for 1 hour, and adjust the solid content to 60 wt% to obtain the bottom glaze slurry.
[0049] 4. Preparation of the surface glaze slurry Take the remaining base glaze slurry equivalent to 30 parts of dry basis, add 4 parts of the core-shell structure antibacterial agent prepared in step 1 and 3 parts of nano-zirconia (average particle size 60nm), ball mill at 200r / min for 1 hour, adjust the solid content to 55wt%, and obtain the surface glaze slurry.
[0050] 5. Glazing and firing Same as Example 1.
[0051] Comparative Example 1 Based on Example 1, instead of adding in-situ crystallization antibacterial components and core-shell structure antibacterial agents, equal amounts of silver-based antibacterial agent AgNO3 and zinc-based antibacterial agent ZnO were added to the base glaze using a simple physical blending method; the rest remained the same as in Example 1.
[0052] Comparative Example 2 Based on Example 1, the sodium bismuthate was replaced with an equal amount of Bi2O3, and the rest remained the same as in Example 1.
[0053] Comparative Example 3 Based on Example 1, sodium bismuthate and silver phosphate were not added, and the amount of zinc oxide added was changed to 6 parts, while the rest remained the same as in Example 1.
[0054] Comparative Example 4 Based on Example 1, a core-shell structured antibacterial agent was not prepared; silver nitrate and zinc nitrate were directly mixed and added, and the rest remained the same as in Example 1.
[0055] Comparative Example 5 Based on Example 1, the core-shell structure does not cover the shell layer, but otherwise remains the same as Example 1.
[0056] Comparative Example 6 Based on Example 1, the bottom glaze slurry and mixture are applied using a single-layer glazing method, while the rest remains the same as in Example 1.
[0057] Comparative Example 7 Based on Example 1, the segmented firing process was omitted, and the temperature was directly increased to 1280°C at a rate of 10°C / min, held for 30 minutes, and then allowed to cool naturally.
[0058] Performance testing: Antibacterial activity: The antibacterial rates of the sample examples and comparative samples against Escherichia coli and Staphylococcus aureus were tested according to the film application method of JC / T 897-2014 standard. Abrasion resistance: Abrasion resistance grades of the tested examples and comparative examples were determined according to GB / T 3810.7-2016 standard. Glaze gloss: Tested according to GB / T 3532-2022 standard; Antibacterial durability: The antibacterial properties of the example and comparative samples were tested after washing 500 times in accordance with GB / T 9266 standard, and the antibacterial rate was compared with that of the unwashed sample to obtain the antibacterial retention rate of Escherichia coli.
[0059]
[0060] The test results show that all examples exhibit excellent antibacterial properties and wear resistance. Example 2, with its optimal bismuth, zinc, and silver ratio (4:3:1), has the highest antibacterial rate, achieving 99.9% and 99.5% antibacterial activity against Escherichia coli and Staphylococcus aureus, respectively. It also boasts the highest antibacterial retention rate and the highest gloss level of 85. Examples 1 and 4, due to their lower total addition amount or lower silver content, have slightly lower antibacterial rates and gloss levels of 82 and 81, respectively, but both achieve a wear resistance level of 4. Examples 3, 5, and 6 have antibacterial rates between 99.0% and 99.5%, retention rates between 93% and 95%, and gloss levels between 83 and 84, all of which meet the usage requirements.
[0061] Comparative Example 1, due to the direct addition of AgNO3 and ZnO, experienced severe volatilization at high temperatures, resulting in a sharp drop in the antibacterial rate to 25% / 20% and a retention rate of only 10%. Furthermore, the volatilization caused micropores in the glaze, reducing the gloss to 68. Comparative Example 2, by replacing sodium bismuthate with Bi2O3, saw its antibacterial rate drop to 92% / 90%, its retention rate to 75%, and its gloss to 75. Comparative Example 3, retaining only ZnO, exhibited extremely poor antibacterial effects and a gloss of 70. Comparative Example 4, lacking core-shell coating, suffered severe silver-zinc volatilization, resulting in an antibacterial rate of only 75% / 70%, a retention rate of 40%, and a gloss of 72. Example 5, though containing a carrier but lacking a shell, achieved an antibacterial rate of 85% / 82%, a retention rate of 50%, and a gloss of 74, demonstrating the importance of the shell layer for high-temperature protection and maintaining glaze gloss. Comparative Example 6, using a single-layer glaze, saw its wear resistance level drop to 3, while maintaining a relatively high antibacterial rate, although the retention rate slightly decreased, and a gloss of 78, proving the contribution of the double-layer structure to wear resistance, surface enrichment, and glaze smoothness. Comparative Example 7, using rapid firing, suffered from poor crystalline phase precipitation, resulting in an antibacterial rate of only 82% / 80%, a wear resistance level dropping to 3, a retention rate of 65%, and a gloss of 71, highlighting the necessity of a segmented firing process. In summary, this invention, through the synergistic effect of in-situ crystallized antibacterial components and core-shell structured antibacterial agents, combined with a double-layer glaze and segmented firing process, effectively maintains high gloss and wear resistance of the glaze while ensuring efficient, broad-spectrum antibacterial action and long-term stability, thus solving the pain points of glaze loss and poor durability caused by the addition of antibacterial components in existing technologies.
[0062] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.
Claims
1. An antibacterial ceramic glaze, characterized in that, It includes a basic glaze matrix and a composite antibacterial system; the composite antibacterial system includes an in-situ crystallized antibacterial component and a core-shell structured antibacterial agent; the in-situ crystallized antibacterial component contains a bismuth source, a zinc source and a silver source, which precipitate a composite antibacterial crystalline phase containing bismuth, zinc and silver in situ from the glass phase of the glaze during the high-temperature sintering and cooling process of the ceramic; the core-shell structured antibacterial agent includes an inorganic carrier core, antibacterial active ions loaded on the core and a shell layer covering the core.
2. The antibacterial ceramic glaze according to claim 1, characterized in that, The inorganic carrier core is nano-zirconium phosphate; the antibacterial active ions include Ag. + Zn 2+ or Cu 2+ .
3. The antibacterial ceramic glaze according to claim 1, characterized in that, The shell is a silicon dioxide shell or a carbon coating layer.
4. The antibacterial ceramic glaze according to claim 1, characterized in that, The basic glaze matrix comprises, by weight, 25-35 parts potassium feldspar, 20-30 parts quartz, 5-10 parts kaolin, 8-15 parts calcite, 5-10 parts wollastonite, 2-5 parts zinc oxide, and 5-10 parts phosphorus-containing frit.
5. The antibacterial ceramic glaze according to claim 1, characterized in that, The amount of the in-situ crystallized antibacterial component added is 3-8% of the weight of the base glaze matrix.
6. The antibacterial ceramic glaze according to claim 1, characterized in that, The amount of the core-shell structure antibacterial agent added is 1-5% of the weight of the base glaze matrix.
7. A method for preparing an antibacterial ceramic glaze as described in any one of claims 1-6, characterized in that, Includes the following steps: (1) The carrier material is pre-calcined and activated, and metal ions are loaded onto the surface of the carrier material by co-precipitation. Then, a shell layer is coated on the surface of the carrier material loaded with metal ions by sol-gel method. The coated product is stabilized at 500-600℃ for 1-2 hours in an inert atmosphere to obtain a core-shell structured antibacterial agent. (2) The basic glaze raw materials, bismuth source, zinc source, silver source and the core-shell structure antibacterial agent prepared in step (1) are mixed and ball-milled to prepare glaze slurry; (3) Apply the glaze slurry prepared in step (2) to the surface of the ceramic body; (4) The glazed ceramic body is fired in sections to obtain antibacterial ceramic products.
8. The method according to claim 7, characterized in that, The glaze application in step (3) is a double-layer glazing process, which includes applying a base glaze first and then a top glaze.
9. The method according to claim 7, characterized in that, In step (4), the segmented firing process includes: the first segment is heated from room temperature to 600°C at a rate of 3-5°C / min; the second segment is heated to 1150°C at a rate of 5-8°C / min; the third segment is heated to 1280°C at a rate of 2-3°C / min, and held at 1280°C for 20-40 minutes.
10. An antibacterial ceramic product, characterized in that, The surface is covered with an antibacterial ceramic glaze as described in any one of claims 1-6; the antibacterial ceramic product includes daily-use ceramics, sanitary ceramics, or building ceramics.