High-light-transmittance low-high-temperature deformation feldspar porcelain and preparation method thereof

Abstract

According to the high-light-transmittance low-high-temperature deformation feldspar porcelain and the preparation method thereof, the content of a mullite crystal phase and the refractive index of a glass phase in a porcelain body are microscopically optimized, and through a macroscopic surface layer high-refractive-index coating, compactly constrained high-viscosity melt resistance is formed on the surface of the porcelain body at a high temperature, so that the high-light-transmittance low-high-temperature deformation feldspar porcelain is obtained; therefore, the light transmittance and the high-temperature plastic deformation resistance of the feldspar porcelain are remarkably improved. According to the invention, a micro-macro dual deformation resistance technology and a dual light transmission compensation technology are adopted, the contradiction that the light transmission performance and the high-temperature deformation resistance of a ceramic material cannot be combined is solved, and the high-light-transmission and low-deformation feldspar porcelain with the light transmission being greater than 55% and the plastic deformation index being less than 2.8 * 10 <-6 > mm <-1 > can be obtained; the used raw materials are non-toxic, pollution-free and environment-friendly, the process is simple and easy to implement, and industrial application and popularization are easy.

Description

Technical Field

[0001] The invention relates to the technical field of ceramic materials, and in particular to a high-transmittance, low-temperature deformed feldspar porcelain and a preparation method thereof. Background Art

[0002] my country's total ceramic output ranks first in the world, and it has become the world's largest ceramic producer and exporter. In 2022, my country's daily-use ceramic output was about 67.39 billion pieces, with a market size of about 94.003 billion yuan. However, for a long time, the appearance and quality of domestic daily-use ceramic products, such as translucency and shape regularity, have a certain gap compared with foreign products. This is bound to be detrimental to the expansion of Chinese ceramics in foreign regional markets, and will also have an impact on the development and promotion of my country's ceramic industry.

[0003] Traditional feldspar porcelain is made of kaolin (50wt%)-feldspar (25wt%)-quartz (25wt%) ternary formula fired at a suitable temperature. It has the advantages of hard texture, good chemical stability and translucency. It is one of the porcelains widely used in the ceramic industry at home and abroad. It is often used for tableware, decorative porcelain and general industrial porcelain. Feldspar porcelain contains a high glass phase (~70%), which can give the ceramic better light transmission performance, but the ceramic body will be easily bent and deformed due to the excessive glass phase during the heating process, which limits its scope of use. Obviously, the high content of glass phase gives feldspar porcelain better light transmission performance, but the excessive content of glass phase at high temperature will cause plastic deformation of the product, poor regularity of the shape, and a significant decrease in the qualified rate. The contradiction formed by the inability to have both is a problem that needs to be solved urgently. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a high-transmittance, low-temperature deformable feldspathic porcelain, which significantly improves the light transmittance and high-temperature plastic deformation resistance of the feldspathic porcelain by micro-optimizing the mullite crystal phase content and glass phase refractive index in the porcelain blank and by macroscopically forming a high-viscosity melt resistance with compact constraints on the surface of the ceramic blank at high temperature through a high-refractive index coating on the surface of the ceramic blank. Another purpose of the present invention is to provide a preparation method for the high-transmittance, low-temperature deformable feldspathic porcelain and a ceramic product thereof.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] The invention provides a high-transmittance, low-temperature deformed feldspar porcelain, which is composed of a daily-use ceramic body and a coating coated on the surface of the body; the content of the mullite crystal phase in the body is 20-50%, the difference in refractive index between the mullite and the glass phase is Δn<0.05; the difference in refractive index between the coating and the body is Δn<0.03, and the high-temperature viscosity of the coating is>10 6 Pa·s.

[0007] Another object of the present invention is achieved by the following technical solutions:

[0008] The method for preparing the high-transmittance, low-temperature deformed feldspar porcelain provided by the present invention comprises the following steps:

[0009] (1) mixing the raw materials of the green body, and subjecting the mixture to ball milling using water as a ball milling medium; drying, grinding, granulating, and sieving the obtained slurry to obtain a powder, and pressing and molding the powder to obtain a green body;

[0010] (2) mixing the raw materials of the coating, adding a binder solution as a ball milling medium for ball milling, and obtaining a coating slurry after sieving; applying the coating slurry on the surface of the green body to obtain a ceramic green body with a coating;

[0011] (3) The ceramic green body with the coating is sintered and naturally cooled to room temperature to obtain high-transmittance, low-temperature deformation feldspar porcelain.

[0012] Furthermore, the raw material composition of the blank of the present invention is quartz 15-35wt%, feldspar 20-40wt%, kaolinite 35-55wt%, polyaluminum mineral 2-10wt%, dolomite 0-5wt%, calcined talc 0-5wt%, barium carbonate 0-4%, rare earth oxide 2-7wt%. The raw material composition of the coating is quartz micropowder 40-65wt%, Al2O3 micropowder 15-25wt%, barium carbonate 0-5wt%, dolomite 10-20wt%, kaolinite 1-10wt%, rare earth oxide 2-9wt%, wherein the particle size of quartz micropowder is 400-800 mesh, and the particle size of Al2O3 micropowder is 400-1000 mesh; the binder solution is a solution of one of CMC, PVA, PVB or a combination thereof, and the concentration of the binder solution is 1-5wt%.

[0013] In the above scheme, the polyaluminum minerals described in the present invention are andalusite and / or kyanite. The rare earth oxides are Y2O3 and / or La2O3.

[0014] Furthermore, in the step (1) of the present invention, the ball milling treatment is carried out according to the ratio of material: ball: water = 1: 2: 0.5-1. In the step (2), the ball milling treatment is carried out according to the ratio of material: ball: binder solution = 1: 2: 1.1-1.5, and the coating thickness of the ceramic green body is 50-450 μm. In the step (3), the sintering treatment is carried out at a temperature of 1280-1350° C., the heating rate is 5-10° C. / min, and the holding time is 60-90 min.

[0015] The product obtained by the preparation method of the high-transmittance and low-temperature deformation feldspathic porcelain has a light transmittance of more than 55% and a plastic deformation index of less than 2.8×10 -6mm -1 .

[0016] The present invention has the following beneficial effects:

[0017] (1) On the one hand, the present invention provides toughening by regulating the mullite content inside the feldspar porcelain, and cooperates with the macroscopic high-viscosity coating on the surface to form a high-viscoelastic melt resistance, thereby achieving "double anti-deformation" to improve the deformation resistance of the ceramic; on the other hand, rare earth oxides (Y2O3, La2O3 or a mixture of the two) are used to regulate the refractive index of the mullite and glass phase inside the blank to reduce the Mie scattering loss and cooperate with the refractive index of the macro coating and the blank to reduce the Fresnel reflection loss, thereby achieving "double light transmission compensation" to improve the light transmittance of the ceramic. Compared with the prior art, the present invention adopts micro-macroscopic dual anti-deformation technology and dual light transmission compensation technology to solve the contradiction between the light transmittance and high-temperature creep performance of ceramic materials, and can obtain a light transmittance greater than 55% and a plastic deformation index less than 2.8×10 -6 mm -1 (The transmittance of feldspar porcelain in the prior art is 45%, and the plastic deformation index is 3.5×10 -6 mm -1 )'s high light transmittance, low deformation feldspar porcelain.

[0018] (2) The raw materials of the present invention are non-toxic and pollution-free, and are environmentally friendly. No toxic low-temperature substances such as B2O3 are required to increase the viscosity. Instead, rare earth oxides (Y2O3, La2O3 or a mixture of the two) are used to increase the refractive index and viscosity. The entire preparation process is green, clean and pollution-free.

[0019] (3) The process of the present invention is simple and easy to implement, and is easy to industrialize and promote.

[0020] The present invention will be described in further detail below with reference to the embodiments. DETAILED DESCRIPTION

[0021] Embodiment 1:

[0022] 1. This embodiment provides a high-transmittance, low-temperature deformable feldspathic porcelain, which is composed of a daily-use ceramic body and a coating applied on the surface of the body.

[0023] The raw material composition of the green body is 22wt% of quartz, 20wt% of feldspar, 43wt% of kaolinite, 5wt% of andalusite, 2wt% of dolomite, 2wt% of calcined talc, 1wt% of barium carbonate, and 5wt% of Y2O3.

[0024] The raw material composition of the coating is 55wt% of quartz powder (particle size is 500 mesh), 20wt% of Al2O3 powder (particle size is 600 mesh), 1wt% of barium carbonate, 14wt% of dolomite, 5wt% of kaolinite, and 5wt% of Y2O3.

[0025] 2. This embodiment provides a method for preparing a high-transmittance, low-temperature deformed feldspar porcelain, and the steps are as follows:

[0026] (1) mixing the raw materials of the green body, and subjecting the mixture to ball milling with water as the ball milling medium (material: ball: water = 1:2:0.5), drying, grinding, granulating, and sieving the obtained slurry to obtain a powder, and pressing and molding the powder to obtain a green body;

[0027] (2) After mixing the raw materials of the coating, a binder solution (PVA solution with a concentration of 1 wt%) is added as a ball milling medium (material: ball: binder solution = 1:2:1.3) and ball milling is performed, and a coating slurry is obtained after sieving; the coating slurry is applied to the surface of the green body to obtain a ceramic green body with a coating (thickness of 200 μm);

[0028] (3) The ceramic green body with coating is sintered by heating the temperature to 1320° C. at a heating rate of 5° C. / min, keeping the temperature for 70 min, and naturally cooling to room temperature, thereby obtaining high-transmittance, low-temperature deformation feldspar porcelain.

[0029] In the high-transmittance, low-temperature deformed feldspar porcelain of this embodiment, the content of mullite crystal phase in the blank is 41%, the difference in refractive index between mullite and glass phase is Δn<0.05; the difference in refractive index between the coating and the blank is Δn<0.03, and the high-temperature viscosity of the coating is 1.5×10 7 Pa·s.

[0030] Embodiment 2:

[0031] 1. This embodiment provides a high-transmittance, low-temperature deformable feldspathic porcelain, which is composed of a daily-use ceramic body and a coating applied on the surface of the body.

[0032] The raw material composition of the green body is 25wt% of quartz, 20wt% of feldspar, 40wt% of kaolinite, 4wt% of andalusite, 2wt% of dolomite, 2wt% of calcined talc, and 7wt% of La2O3.

[0033] The raw material composition of the coating is 60wt% of quartz powder (particle size is 400 mesh), 16wt% of Al2O3 powder (particle size is 500 mesh), 14wt% of dolomite, 3wt% of kaolinite, and 7wt% of La2O3.

[0034] 2. This embodiment provides a method for preparing a high-transmittance, low-temperature deformed feldspar porcelain, and the steps are as follows:

[0035] (1) mixing the raw materials of the green body, and subjecting the mixture to ball milling with water as the ball milling medium (material: ball: water = 1:2:0.5), drying, grinding, granulating, and sieving the obtained slurry to obtain a powder, and pressing and molding the powder to obtain a green body;

[0036] (2) After mixing the raw materials of the coating, a binder solution (PVB solution with a concentration of 1 wt%) is added as a ball milling medium (material: ball: binder solution = 1:2:1.1) and ball milling is performed, and a coating slurry is obtained after sieving; the coating slurry is applied to the surface of the green body to obtain a ceramic green body with a coating (thickness of 300 μm);

[0037] (3) The ceramic green body with the coating is sintered by heating the temperature to 1300° C. at a heating rate of 5° C. / min, keeping the temperature for 65 min, and naturally cooling to room temperature, thereby obtaining a high-transmittance, low-temperature deformation feldspar porcelain.

[0038] In the present embodiment, the high-transmittance, low-temperature deformed feldspar porcelain has a mullite crystal phase content of 35% in the body, a relative refractive index difference between mullite and glass phase Δn<0.041; a refractive index difference between the coating and the body Δn<0.022, and a high-temperature viscosity of the coating of 3.4×10 6 Pa·s.

[0039] Embodiment three:

[0040] 1. This embodiment provides a high-transmittance, low-temperature deformable feldspathic porcelain, which is composed of a daily-use ceramic body and a coating applied on the surface of the body.

[0041] The raw material composition of the green body is 23wt% of quartz, 25wt% of feldspar, 40wt% of kaolinite, 5wt% of andalusite, 2wt% of dolomite, 2wt% of calcined talc, and 3wt% of Y2O3.

[0042] The raw material composition of the coating is 60wt% of quartz powder (particle size is 800 mesh), 20wt% of Al2O3 powder (particle size is 800 mesh), 14wt% of dolomite, 1wt% of barium carbonate, 2wt% of kaolinite, and 3wt% of Y2O3.

[0043] 2. This embodiment provides a method for preparing a high-transmittance, low-temperature deformed feldspar porcelain, and the steps are as follows:

[0044] (1) mixing the raw materials of the green body, and subjecting the mixture to ball milling with water as the ball milling medium (material: ball: water = 1:2:0.5), drying, grinding, granulating, and sieving the obtained slurry to obtain a powder, and pressing and molding the powder to obtain a green body;

[0045] (2) After mixing the raw materials of the coating, a binder solution (PVA solution with a concentration of 2 wt%) was added as a ball milling medium (material: ball: binder solution = 1:2:1.3) and ball milling was performed, and a coating slurry was obtained after sieving; the coating slurry was applied to the surface of the green body to obtain a ceramic green body with a coating (thickness of 150 μm);

[0046] (3) The ceramic green body with the coating is sintered by heating the temperature to 1310° C. at a heating rate of 7° C. / min, keeping the temperature for 60 min, and naturally cooling to room temperature, thereby obtaining a high-transmittance, low-temperature deformation feldspar porcelain.

[0047] In the high-transmittance, low-temperature deformed feldspar porcelain of this embodiment, the content of mullite crystal phase in the blank is 37%, the difference in refractive index between mullite and glass phase is Δn<0.039; the difference in refractive index between the coating and the blank is Δn<0.025, and the high-temperature viscosity of the coating is 2.5×10 6 Pa·s.

[0048] Embodiment 4:

[0049] 1. This embodiment provides a high-transmittance, low-temperature deformable feldspathic porcelain, which is composed of a daily-use ceramic body and a coating applied on the surface of the body.

[0050] The raw material composition of the green body is 20wt% of quartz, 25wt% of feldspar, 40wt% of kaolinite, 3wt% of kyanite, 2wt% of dolomite, 2wt% of calcined talc, 2wt% of barium carbonate, and 6wt% of Y2O3.

[0051] The raw material composition of the coating is 60wt% of quartz powder (particle size is 600 mesh), 18wt% of Al2O3 powder (particle size is 800 mesh), 10wt% of dolomite, 3wt% of barium carbonate, 1wt% of kaolinite, and 8wt% of Y2O3.

[0052] 2. This embodiment provides a method for preparing a high-transmittance, low-temperature deformed feldspar porcelain, and the steps are as follows:

[0053] (1) mixing the raw materials of the green body, and subjecting the mixture to ball milling with water as the ball milling medium (material: ball: water = 1:2:0.5), drying, grinding, granulating, and sieving the obtained slurry to obtain a powder, and pressing and molding the powder to obtain a green body;

[0054] (2) After mixing the raw materials of the coating, a binder solution (PVA solution with a concentration of 2 wt%) is added as a ball milling medium (material: ball: binder solution = 1:2:1.5) and ball milling is performed, and a coating slurry is obtained after sieving; the coating slurry is applied to the surface of the green body to obtain a ceramic green body with a coating (thickness of 400 μm);

[0055] (3) The ceramic green body with the coating is sintered by heating the temperature to 1280° C. at a heating rate of 10° C. / min, keeping the temperature for 90 min, and naturally cooling the green body to room temperature, thereby obtaining a high-transmittance, low-temperature deformation feldspar porcelain.

[0056] In the high-transmittance, low-temperature deformed feldspar porcelain of this embodiment, the content of mullite crystal phase in the blank is 28%, the difference in refractive index between mullite and glass phase is Δn<0.035; the difference in refractive index between the coating and the blank is Δn<0.02, and the high-temperature viscosity of the coating is 1.2×10 7 Pa·s.

[0057] The feldspar porcelain prepared in each embodiment of the present invention is tested for transmittance using GB / T 3296-2021; the ceramic plastic deformation index is determined using the PDI value in the following formula.

[0058] PDI=4b 2 S / 3L 4

[0059] Wherein, PDI is the plastic deformation index (mm -1 ); b is the thickness of the sample (mm); S is the deformation of the sample after sintering (mm); L is the distance between the sample fulcrums (mm).

[0060] The test results of the feldspar porcelain of various embodiments of the present invention are shown in Table 1.

[0061] Table 1 Transparency and plastic deformation index of feldspar porcelain in various embodiments of the present invention

[0062]

Claims

1. A high light transmittance, low temperature deformation feldspar porcelain, characterized by: The invention is composed of a daily-use ceramic body and a coating applied on the surface of the body; the content of the mullite crystal phase in the body is 20-50%, the difference in refractive index between the mullite and the glass phase is Δn<0.05; the difference in refractive index between the coating and the body is Δn<0.03, and the high-temperature viscosity of the coating is>10 6 Pa·s.

2. The method for preparing the high-transmittance, low-temperature deformed feldspathic porcelain according to claim 1, characterized in that The following steps are involved: (1) mixing the raw materials of the green body, and subjecting the mixture to ball milling using water as a ball milling medium; drying, grinding, granulating, and sieving the obtained slurry to obtain a powder, and pressing and molding the powder to obtain a green body; (2) mixing the raw materials of the coating, adding a binder solution as a ball milling medium for ball milling, and obtaining a coating slurry after sieving; applying the coating slurry on the surface of the green body to obtain a ceramic green body with a coating; (3) The ceramic green body with the coating is sintered and naturally cooled to room temperature to obtain high-transmittance, low-temperature deformation feldspar porcelain.

3. The method for preparing the high light transmittance low high temperature deformation feldspar porcelain according to claim 2, characterized in that: The raw material composition of the green body is 15-35wt% of quartz, 20-40wt% of feldspar, 35-55wt% of kaolinite, 2-10wt% of polyaluminum minerals, 0-5wt% of dolomite, 0-5wt% of calcined talc, 0-4% of barium carbonate and 2-7wt% of rare earth oxides.

4. The method for preparing high-transmittance, low-temperature deformed feldspar porcelain according to claim 2, characterized in that: The raw material composition of the coating is 40-65wt% of quartz micropowder, 15-25wt% of Al2O3 micropowder, 0-5wt% of barium carbonate, 10-20wt% of dolomite, 1-10wt% of kaolinite, and 2-9wt% of rare earth oxides, wherein the particle size of the quartz micropowder is 400-800 meshes, and the particle size of the Al2O3 micropowder is 400-1000 meshes; the binder solution is a solution of one of CMC, PVA, PVB or a combination thereof, and the concentration of the binder solution is 1-5wt%.

5. The method for preparing the high-transmittance, low-temperature deformed feldspathic porcelain according to claim 2, characterized in that: The polyaluminum mineral is andalusite and / or kyanite.

6. The method for preparing high-transmittance, low-temperature deformed feldspathic porcelain according to claim 3 or 4, characterized in that: The rare earth oxide is Y2O3 and / or La2O3.

7. The method for preparing high-transmittance, low-temperature deformed feldspathic porcelain according to claim 2, characterized in that: The step (1) is ball milled according to the ratio of material: ball: water = 1:2:0.5-1.

8. The method for preparing high-transmittance, low-temperature deformed feldspar porcelain according to claim 2, characterized in that: In the step (2), ball milling is performed according to the ratio of material: ball: binder solution = 1:2:1.1-1.5, and the coating thickness of the ceramic green body is 50-450 μm.

9. The method for preparing high-transmittance, low-temperature deformed feldspathic porcelain according to claim 2, characterized in that: The step (3) is sintered at a temperature of 1280-1350° C., a heating rate of 5-10° C. / min, and a heat preservation time of 60-90 min.

10. A product obtained by the method for preparing high-transmittance, low-temperature deformed feldspathic porcelain according to any one of claims 2 to 9, characterized in that: The light transmittance of the feldspar porcelain is greater than 55%, and the plastic deformation index is less than 2.8×10 -6 mm -1 .

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