Antibacterial glaze for ceramic products and method for preparing the same

Abstract

This invention relates to the field of ceramic glaze technology and discloses an antibacterial glaze for ceramic products and its preparation method. The raw materials of the antibacterial glaze of this invention include 30-38 parts by weight of potassium feldspar, 26-40 parts by weight of quartz, 3-8 parts by weight of calcite, 2-4 parts by weight of alumina, 2-3.5 parts by weight of zirconium silicate, 1-3 parts by weight of dolomite, and 0.5-3 parts by weight of diatomaceous earth-loaded silver antibacterial agent. The modified diatomaceous earth contains a large number of hydroxyl groups, carboxyl groups, and multiple salicylaldehyde Schiff base structures, which have a strong coordination complexing ability for silver ions. It can uniformly load a large number of silver ions onto the surface of diatomaceous earth, improving the loading and dispersibility of the silver antibacterial agent. When added to the ceramic glaze, it endows the glaze with excellent antibacterial properties and has good practical applications in antibacterial ceramics and ceramic products.

Description

Technical Field

[0001] This invention relates to the field of ceramic glaze technology, specifically to an antibacterial glaze for ceramic products and its preparation method. Background Technology

[0002] Antibacterial ceramics are widely used in sanitary ware, daily-use ceramics, and art ceramics. They typically involve adding antibacterial agents to the glaze or ceramic matrix. Silver antibacterial agents are non-toxic, pollution-free, have few side effects on the human body, and possess strong antibacterial properties, making them widely applicable. Silver antibacterial agents usually need to be loaded onto a carrier to achieve effects such as slow release, long-lasting antibacterial action, high-temperature resistance, and reduced agglomeration. Common carriers for antibacterial agents include zeolite, silica, and zirconium phosphate.

[0003] Diatomaceous earth, with its large specific surface area and readily available low cost, is an excellent carrier for antibacterial agents and has important applications in ceramics and plastics. However, diatomaceous earth exhibits poor loading performance for silver antibacterial agents, necessitating organic functionalization modification. This invention utilizes modified diatomaceous earth as a carrier for silver antibacterial agents, aiming to improve the antibacterial properties of glazes and ceramic products. Summary of the Invention

[0004] This invention solves the problems of poor dispersibility of silver antibacterial agents and poor antibacterial properties of ceramic glazes.

[0005] The technical solution of the present invention is: an antibacterial glaze for ceramic products, the raw materials of which include 30-38 parts by weight of potassium feldspar, 26-40 parts by weight of quartz, 3-8 parts by weight of calcite, 2-4 parts by weight of alumina, 2-3.5 parts by weight of zirconium silicate, 1-3 parts by weight of dolomite, and 0.5-3 parts by weight of diatomite-supported silver antibacterial agent.

[0006] The preparation method of diatomaceous earth-supported silver antibacterial agent is as follows:

[0007] (1) Add diatomaceous earth and 3-formyl-4-hydroxybenzoic acid diamino-2-propanol Schiff base to deionized water, stir to modify, filter, wash with water and ethanol, and dry to obtain modified diatomaceous earth.

[0008] (2) Add modified diatomaceous earth and silver nitrate to water, stir to load, filter, wash with water, and dry to obtain diatomaceous earth loaded with silver antibacterial agent.

[0009] Preferably, in (1), the amount of diatomaceous earth is 100 parts by weight and the amount of 3-formyl-4-hydroxybenzoic acid diamino-2-propanol Schiff base is 20-50 parts by weight.

[0010] Preferably, the stirring temperature in (1) is 30-60℃ and the stirring time is 4-7h.

[0011] Preferably, in (2), the amount of modified diatomaceous earth is 100 parts by weight and the amount of silver nitrate is 10-30 parts by weight.

[0012] Preferably, the temperature during stirring in (2) is 20-30℃ and the time is 2-4h.

[0013] Preferably, the preparation method of 3-formyl-4-hydroxybenzoic acid diamino-2-propanol Schiff base is as follows: 3-formyl-4-hydroxybenzoic acid diamino-2-propanol is added to ethanol, the mixture is stirred and reacted, then heated to volatilize, and cooled to crystallize, thereby obtaining 3-formyl-4-hydroxybenzoic acid diamino-2-propanol Schiff base.

[0014] Preferably, the ratio of 3-formyl-4-hydroxybenzoic acid condensate to 1,3-diamino-2-propanol is (2-2.1) mol:1 mol.

[0015] Preferably, the temperature during the stirring reaction is 70-80℃, and the reaction time is 7-10h.

[0016] Preferably, the method for preparing antibacterial glaze is as follows: water, potassium feldspar, quartz, calcite, alumina, zirconium silicate, dolomite, and diatomaceous earth loaded with silver antibacterial agent are added to a ball mill jar, ball milled, and discharged to obtain antibacterial glaze.

[0017] Preferably, the ball milling speed is 200-400 r / min and the ball milling time is 0.5-2 h.

[0018] Preferably, antibacterial glazes are used in antibacterial ceramic products.

[0019] The beneficial technical effects of this invention are as follows: The 3-formyl-4-hydroxybenzoic acid diamino-2-propanol Schiff base of this invention contains multiple carboxyl groups, which can form a strong interaction with the surface of diatomaceous earth, thereby modifying it into the diatomaceous earth matrix. The resulting modified diatomaceous earth contains a large number of hydroxyl groups, carboxyl groups, and multiple salicylaldehyde Schiff base structures, which have a strong coordination and complexation ability for silver ions. It can uniformly load a large number of silver ions onto the surface of diatomaceous earth, improving the loading and dispersibility of silver antibacterial agents. When added to ceramic glazes, it endows the glazes with excellent antibacterial properties and has good practical applications in antibacterial ceramics, sanitary products, etc. Detailed Implementation

[0020] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0021] Example 1

[0022] (1) Add 0.2 mol of 3-formyl-4-hydroxybenzoic acid condensate and 0.1 mol of 1,3-diamino-2-propanol to 0.8 L of ethanol, heat to 80 °C, reflux for 7 h, evaporate upon heating, cool and crystallize to obtain the Schiff base of 3-formyl-4-hydroxybenzoic acid condensate diamino-2-propanol, the reaction formula is:

[0023] .

[0024] (2) Add 200g of diatomaceous earth and 40g of 3-formyl-4-hydroxybenzoic acid diamino-2-propanol Schiff base to 2.5L of deionized water, stir and modify at 40℃ for 4h, filter, wash with water and ethanol, and dry to obtain modified diatomaceous earth.

[0025] (3) Add 200g of modified diatomaceous earth and 20g of silver nitrate to 2L of water, stir and load at 30℃ for 2h, filter, wash with water, and dry to obtain diatomaceous earth loaded with silver antibacterial agent.

[0026] (4) Add 2.3L of water, 3.3kg of potassium feldspar, 4kg of quartz, 0.3kg of calcite, 0.4kg of alumina, 0.26kg of zirconium silicate, 0.3kg of dolomite, and 50g of diatomaceous earth-loaded silver antibacterial agent to the ball mill jar, and ball mill for 2 hours at a speed of 200r / min. Discharge the material to obtain antibacterial glaze.

[0027] Example 2

[0028] (1) Add 0.22 mol of 3-formyl-4-hydroxybenzoic acid condensate and 0.1 mol of 1,3-diamino-2-propanol to 1 L of ethanol, heat to 70 °C, reflux for 10 h, heat to volatilize, cool to crystallize, and obtain 3-formyl-4-hydroxybenzoic acid condensate diamino-2-propanol Schiff base.

[0029] (2) Add 200g of diatomaceous earth and 70g of 3-formyl-4-hydroxybenzoic acid diamino-2-propanol Schiff base to 3L of deionized water, stir and modify at 60℃ for 4h, filter, wash with water and ethanol, and dry to obtain modified diatomaceous earth.

[0030] (3) Add 200g of modified diatomaceous earth and 40g of silver nitrate to 2 L of water, stir and load at 20℃ for 4h, filter, wash with water, and dry to obtain diatomaceous earth loaded with silver antibacterial agent.

[0031] (4) Add 2.8L water, 3kg potassium feldspar, 3.5kg quartz, 0.8kg calcite, 0.2kg alumina, 0.35kg zirconium silicate, 0.24kg dolomite, and 150g diatomaceous earth-loaded silver antibacterial agent to the ball mill jar, and ball mill for 0.5h at a speed of 400r / min. Discharge the material to obtain antibacterial glaze.

[0032] Example 3

[0033] (1) Prepare 3-formyl-4-hydroxybenzoic acid diamino-2-propanol Schiff base according to the method of Example 1.

[0034] (2) Add 200g of diatomaceous earth and 100g of 3-formyl-4-hydroxybenzoic acid diamino-2-propanol Schiff base to 3L of deionized water, stir and modify at 30℃ for 7h, filter, wash with water and ethanol, and dry to obtain modified diatomaceous earth.

[0035] (3) Add 200g of modified diatomaceous earth and 60g of silver nitrate to 2.5L of water, stir and load at 25℃ for 4h, filter, wash with water, and dry to obtain diatomaceous earth loaded with silver antibacterial agent.

[0036] (4) Add 2L of water, 3.8kg of potassium feldspar, 2.6kg of quartz, 0.6kg of calcite, 0.28kg of alumina, 0.2kg of zirconium silicate, 0.1kg of dolomite, and 300g of diatomaceous earth-loaded silver antibacterial agent to the ball mill jar, ball mill for 1 hour at a speed of 400r / min, and discharge the material to obtain antibacterial glaze.

[0037] Comparative Example 1

[0038] (1) Add 2.3L water, 3.3kg potassium feldspar, 4kg quartz, 0.3kg calcite, 0.4kg alumina, 0.26kg zirconium silicate, 0.3kg dolomite and 50g modified diatomaceous earth to the ball mill jar, ball mill for 2 hours at a speed of 200r / min, and discharge the material to obtain the glaze.

[0039] Comparative Example 2

[0040] (1) Add 200g of diatomaceous earth and 20g of silver nitrate to 2L of water, stir and load at 30℃ for 2h, filter, wash with water, and dry to obtain diatomaceous earth loaded with silver antibacterial agent.

[0041] (2) Add 2.3L of water, 3.3kg of potassium feldspar, 4kg of quartz, 0.3kg of calcite, 0.4kg of alumina, 0.26kg of zirconium silicate, 0.3kg of dolomite, and 50g of diatomaceous earth-loaded silver antibacterial agent to a ball milling jar, and ball mill for 2 hours at a speed of 200r / min. Discharge the material to obtain an antibacterial glaze.

[0042] Comparative Example 3

[0043] (1) Add 0.2 mol of salicylaldehyde and 0.1 mol of 1,3-diamino-2-propanol to 0.8 L of ethanol, heat to 80 °C, reflux for 7 h, then allow to evaporate upon heating and cool to crystallize, yielding a salicylaldehyde diamino-2-propanol Schiff base with the following structural formula: .

[0044] (2) Add 200g of diatomaceous earth and 40g of salicylaldehyde diamino-2-propanol Schiff base to 2.5L of deionized water, stir and modify at 40℃ for 4h, filter, wash with water and ethanol, and dry to obtain modified diatomaceous earth.

[0045] (3) Add 200g of modified diatomaceous earth and 20g of silver nitrate to 2L of water, stir and load at 30℃ for 2h, filter, wash with water, and dry to obtain diatomaceous earth loaded with silver antibacterial agent.

[0046] (4) Add 2.3L of water, 3.3kg of potassium feldspar, 4kg of quartz, 0.3kg of calcite, 0.4kg of alumina, 0.26kg of zirconium silicate, 0.3kg of dolomite, and 50g of diatomaceous earth-loaded silver antibacterial agent to the ball mill jar, and ball mill for 2 hours at a speed of 200r / min. Discharge the material to obtain antibacterial glaze.

[0047] Comparative Example 4

[0048] (1) Add 0.2 mol of 3-formyl-4-hydroxybenzoic acid condensate and 0.1 mol of ethylenediamine to 0.8 L of ethanol, heat to 80 °C, reflux for 7 h, evaporate upon heating, cool and crystallize to obtain 3-formyl-4-hydroxybenzoic acid condensate ethylenediamine Schiff base, with the structural formula as follows: .

[0049] (2) Add 200g of diatomaceous earth and 40g of 3-formyl-4-hydroxybenzoic acid ethylenediamine Schiff base to 2.5L of deionized water, stir and modify at 40℃ for 4h, filter, wash with water and ethanol, and dry to obtain modified diatomaceous earth.

[0050] (3) Add 200g of modified diatomaceous earth and 20g of silver nitrate to 2L of water, stir and load at 30℃ for 2h, filter, wash with water, and dry to obtain diatomaceous earth loaded with silver antibacterial agent.

[0051] (4) Add 2.3L of water, 3.3kg of potassium feldspar, 4kg of quartz, 0.3kg of calcite, 0.4kg of alumina, 0.26kg of zirconium silicate, 0.3kg of dolomite, and 50g of diatomaceous earth-loaded silver antibacterial agent to the ball mill jar, and ball mill for 2 hours at a speed of 200r / min. Discharge the material to obtain antibacterial glaze.

[0052] Comparative Example 5

[0053] (1) Add 200g of diatomaceous earth and 40g of citric acid to 2.5L of deionized water, stir at 40℃ for 4h to modify, filter, wash with water and ethanol, and dry to obtain modified diatomaceous earth.

[0054] (2) Add 200g of modified diatomaceous earth and 20g of silver nitrate to 2L of water, stir and load at 30℃ for 2h, filter, wash with water, and dry to obtain diatomaceous earth loaded with silver antibacterial agent.

[0055] (3) Add 2.3L of water, 3.3kg of potassium feldspar, 4kg of quartz, 0.3kg of calcite, 0.4kg of alumina, 0.26kg of zirconium silicate, 0.3kg of dolomite, and 50g of diatomaceous earth-loaded silver antibacterial agent to the ball mill jar, and ball mill for 2 hours at a speed of 200r / min. Discharge the material to obtain antibacterial glaze.

[0056] The glaze is applied to the ceramic body, dried at 90℃ for 2 hours, and then placed in a kiln. The temperature is first raised to 500℃ and held for 2 hours, then raised to 1200℃ and held for 2 hours. After cooling, ceramic products with antibacterial glaze are obtained. The antibacterial properties are tested according to JC / T 897-2014 standard.

[0057] The antibacterial rate R = (BC) / B × 100%, where B is the average colony count of the blank control sample (Comparative Example 1) after 24 hours of incubation; and C is the average colony count of the antibacterial ceramic sample after 24 hours of incubation.

[0058] Table 1 Antibacterial properties of ceramic glazes

[0059]

[0060] The ceramic glazes of Examples 1-3 exhibit higher antibacterial rates, primarily due to the addition of diatomaceous earth-loaded silver antibacterial agents. The 3-formyl-4-hydroxybenzoic acid diamino-2-propanol Schiff base contains multiple carboxyl groups, which can form a strong interaction with the diatomaceous earth surface, thereby modifying the diatomaceous earth matrix. This introduces a large number of hydroxyl, carboxyl, and multiple salicylaldehyde Schiff base structures onto the diatomaceous earth surface, exhibiting a strong coordination and complexation ability for silver ions. This allows a large number of silver ions to be uniformly loaded onto the diatomaceous earth surface, improving the loading and dispersibility of the silver antibacterial agent. When added to the ceramic glaze, it endows the glaze with excellent antibacterial properties.

[0061] The diatomaceous earth in Comparative Example 2 does not contain hydroxyl, carboxyl, salicylaldehyde Schiff base and other structures, and has poor loading performance for silver ions. After washing, silver ions are easily washed away from the diatomaceous earth matrix, which seriously affects the antibacterial properties of the glaze.

[0062] The salicylaldehyde diamino-2-propanol Schiff base in Comparative Example 3 does not contain a carboxyl group, resulting in low interaction with the diatomaceous earth surface. This makes it difficult to modify the diatomaceous earth surface and hinders the coordination and complexation of silver ions with diatomaceous earth. After washing, silver ions are easily washed away from the diatomaceous earth matrix, affecting the antibacterial properties of the glaze.

[0063] The 3-formyl-4-hydroxybenzoic acid ethylenediamine Schiff base in Comparative Example 4 has a lower hydroxyl content and a lower ability to coordinate and complex silver ions than in Example 1. This results in a lower loading and dispersibility of silver antibacterial agent in diatomaceous earth compared to Example 1, and a lower antibacterial rate of the glaze.

[0064] Comparative Example 5 modified diatomaceous earth with conventional citric acid, and the antibacterial rate of the glaze was significantly lower than that of Example 1.

[0065] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. An antibacterial glaze for ceramic products, characterized in that, The raw materials of the antibacterial glaze include 30-38 parts by weight of potassium feldspar, 26-40 parts by weight of quartz, 3-8 parts by weight of calcite, 2-4 parts by weight of alumina, 2-3.5 parts by weight of zirconium silicate, 1-3 parts by weight of dolomite, and 0.5-3 parts by weight of diatomite-supported silver antibacterial agent. The preparation method of the diatomaceous earth-supported silver antibacterial agent is as follows: (1) Add diatomaceous earth and 3-formyl-4-hydroxybenzoic acid diamino-2-propanol Schiff base to deionized water, stir to modify, filter, wash and dry to obtain modified diatomaceous earth. (2) Add modified diatomaceous earth and silver nitrate to water, stir to load, filter, wash and dry to obtain diatomaceous earth loaded with silver antibacterial agent.

2. The antibacterial glaze according to claim 1, wherein The amount of diatomaceous earth used in (1) is 100 parts by weight, and the amount of 3-formyl-4-hydroxybenzoic acid diamino-2-propanol Schiff base is 20-50 parts by weight.

3. The antibacterial glaze according to claim 1, wherein The stirring temperature in (1) is 30-60℃ and the stirring time is 4-7h.

4. The antibacterial glaze of claim 1, wherein In (2), the amount of modified diatomaceous earth is 100 parts by weight and the amount of silver nitrate is 10-30 parts by weight.

5. The antibacterial glaze of claim 1, wherein The temperature during stirring in (2) is 20-30℃ and the time is 2-4h.

6. The antibacterial glaze of claim 2, wherein The preparation method of the 3-formyl-4-hydroxybenzoic acid diamino-2-propanol Schiff base is as follows: 3-formyl-4-hydroxybenzoic acid diamino-2-propanol in a ratio of (2-2.1) mol:1 mol is added to ethanol, heated to 70-80℃, stirred and refluxed for 7-10 h, then heated to volatilize, cooled and crystallized to obtain the 3-formyl-4-hydroxybenzoic acid diamino-2-propanol Schiff base.

7. A method for producing the antibacterial glaze according to any one of claims 1 to 6, characterized by, The preparation method is as follows: water, potassium feldspar, quartz, calcite, alumina, zirconium silicate, dolomite, and diatomaceous earth loaded with silver antibacterial agent are added to a ball mill jar, ball milled, and discharged to obtain an antibacterial glaze.

8. The method of producing an antibacterial glaze according to claim 7, wherein The ball milling speed is 200-400 r / min, and the ball milling time is 0.5-2 h.

9. The application of an antibacterial glaze obtained by any one of claims 1-7 in antibacterial ceramic products.

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