Low-glossiness skin texture glaze, ultralow-glossiness skin texture ceramic tile and preparation method of low-glossiness skin texture glaze and ultralow-glossiness skin texture ceramic tile

Abstract

The invention belongs to the technical field of architectural ceramics, and particularly relates to a low-gloss skin texture glaze, an ultralow-gloss skin texture ceramic tile and a preparation method of the low-gloss skin texture glaze and the ultralow-gloss skin texture ceramic tile. The low-gloss skin texture glaze comprises the following mineral components in percentage by mass: 18%-22% of sintered mullite, 6%-8% of nano silicon dioxide, 7%-10% of wollastonite, 10%-13% of calcined talc, 2%-5% of quartz, 3%-5% of calcined zinc oxide, 4%-6% of kaolin, 18%-22% of medium-temperature frit and 16%-20% of high-temperature frit. According to the invention, the development of the ultra-low-glossiness skin-texture ceramic tile is realized. The process disclosed by the invention is simple and easy to implement, the glossiness of the glaze surface of the product is stable and controllable, the product has no crystal spot defect, has fine skin texture, ensures ultralow glossiness and also has excellent antifouling property.

Description

Technical Field

[0001] This invention belongs to the field of architectural ceramics technology, and particularly relates to a low-gloss skin-textured glaze, an ultra-low gloss skin-textured ceramic tile, and a method for preparing the same. Background Technology

[0002] High-gloss polished tiles and glazed tiles (gloss level > 90) reflect light strongly, leading to significant light pollution when used in interior decoration. Therefore, in recent years, low-gloss non-polished ceramic tiles have become increasingly popular with end consumers.

[0003] To reduce the gloss of polished products, the building ceramics industry currently uses a combination of coarser polishing blocks to perform a so-called "soft polishing" on the glaze surface in addition to the existing polishing process. This essentially increases the roughness of the glaze surface after polishing. However, this process opens up the closed pores in the glaze layer, and the increased surface roughness leads to a sharp decrease in the product's stain resistance. Even waxing to fill the pores cannot fundamentally solve this problem, and due to the limitation of stain resistance, the product's gloss can only be controlled at a minimum of around 30 degrees.

[0004] Currently, the gloss level of non-polished skin-like products on the market is generally between 15 and 25 degrees, and they are mainly based on the barium (strontium) feldspar system. The principle behind their skin-like texture and low gloss is that a large amount of barium (strontium) oxide is introduced into the glaze formula. During the firing process, the irregular precipitation of barium (strontium) feldspar crystals on the glaze surface causes diffuse reflection of light. Furthermore, because the precipitated barium (strontium) feldspar crystals are small in size, the glaze surface roughness is low, thus providing a better tactile feel.

[0005] Patent publication number CN 117361880 A proposes a warm jade skin glaze ceramic tile and its preparation method, which introduces high barium frit with a barium content of 30-38% and barium carbonate as raw materials into the warm jade skin glaze.

[0006] Patent publication number CN 118561520 B proposes a satin glaze with a silky smooth feel, ceramic tiles and their preparation method. The formula also uses a high barium system of 10-20 parts barium feldspar and 20-30 parts barium-based matte frit powder, and proposes to use Ba, Al2O3 and SiO2 as the main crystallizing agents to obtain a stable barium feldspar main crystal phase, thereby improving the satin effect of the glaze.

[0007] However, while the above technical solutions create a skin-like or satin-like effect through the precipitation of barium feldspar, the irregular distribution of barium feldspar crystals on the glaze surface between precipitated and non-precipitated areas results in uncontrollable crystalline spots when observed under light, reducing the surface effect and grade of the product. Strontium-based glazes also have similar problems, and strontium-containing raw materials are more expensive, and the gloss level of the glaze is difficult to control below 15 degrees, therefore they are less commonly used.

[0008] Currently, there is an urgent demand in the end-user market for ceramic tile products with ultra-low gloss (≤8) that are free of crystal spots and have a skin-like texture. Summary of the Invention

[0009] To achieve the development of skin-textured ceramic tiles with ultra-low gloss and no crystal defects, this invention provides an ultra-low gloss skin-textured ceramic tile and its preparation method.

[0010] In a first aspect, the present invention provides a low-gloss skin-textured glaze. The mineral composition of the low-gloss skin-textured glaze comprises, by mass percentage: 18%–22% sintered mullite, 6%–8% nano-silica, 7%–10% wollastonite, 10%–13% calcined talc, 2%–5% quartz, 3%–5% calcined zinc oxide, 4%–6% kaolin, 18%–22% medium-temperature frit, and 16%–20% high-temperature frit.

[0011] Preferably, the initial melting temperature of the medium-temperature fused block is 1060–1080 °C; more preferably, the chemical composition of the medium-temperature fused block includes, by mass percentage: SiO2 48%–50%, Al2O3 14%–18%, CaO 12%–15%, MgO 5.5%–8.0%, K2O 4.5%–8.0%, Na2O 2.5%–5.0%, BaO 1.5%–3.0%, ZnO 5.5%–9.5%.

[0012] Preferably, the initial melting temperature of the high-temperature molten ingot is 1120–1140°C; more preferably, the chemical composition of the high-temperature molten ingot includes, by mass percentage: SiO2 51%–54%, Al2O3 24%–26%, CaO 15%–17%, MgO 1.0%–4.0%, K2O 3.0%–8.0%, Na2O 1.5%–4.0%.

[0013] Preferably, the chemical composition of the low-gloss skin-textured glaze includes, by mass percentage: 48%–55% SiO2, 23%–26% Al2O3, 10%–15% CaO, 3.5%–6.0% MgO, 1.5%–4.0% K2O, 0.8%–2.0% Na2O, 0.5%–2.0% BaO, and 4.5%–8.0% ZnO.

[0014] Preferably, the low-gloss skin-textured glaze uniformly precipitates labradorite crystals after firing, and the labradorite crystals are distributed in the lattice gaps formed by the mullite crystals.

[0015] Secondly, the present invention provides a method for preparing ultra-low gloss, skin-textured ceramic tiles. The preparation method includes: Apply a surface glaze to the body; Ceramic ink is inkjet printed onto the surface of the glazed body. Apply the low-gloss skin-textured glaze to the surface of the blank after inkjet printing ceramic ink; The body with the low-gloss skin-textured glaze is fired to obtain ultra-low gloss skin-textured ceramic tiles.

[0016] Preferably, the low-gloss skin-textured glaze is applied by pouring or spraying; when using a pouring process, the specific gravity of the low-gloss skin-textured glaze is 1.72–1.80 g / cm³. 3 The glaze application amount is 540-580 g / m². 2 When using a spray glazing process, the specific gravity of a low-gloss, skin-textured glaze is 1.55–1.65 g / cm³. 3 The glaze application amount is 625-700 g / m². 2 .

[0017] Preferably, the ceramic ink includes colored ink and / or functional ink; the functional ink includes engraving ink or glossy ink.

[0018] Preferably, the chemical composition of the glaze comprises, by mass percentage: SiO2 49%–52%, Al2O3 26%–29%, Fe2O3 0.2%–0.5%, CaO 0.2%–0.8%, MgO 0.3%–0.6%, K2O 3.5%–5.0%, Na2O 2.0%–3.0%, ZrO2 7.0%–9.0%, and loss on ignition 3.5%–5.0%.

[0019] Preferably, the glaze is applied by pouring or spraying; the specific gravity of the glaze is 1.40–1.45 g / cm³. 3 The glaze application rate is 400-550 g / m². 2 .

[0020] Preferably, the firing temperature is 1140–1160℃ and the firing cycle is 50–70 min.

[0021] Thirdly, the present invention provides an ultra-low gloss skin-textured ceramic tile. The ultra-low gloss skin-textured ceramic tile is obtained according to the aforementioned preparation method.

[0022] The present invention has the following beneficial effects:

[0023] This invention enables the development of ultra-low gloss, skin-like textured ceramic tiles. The process is simple and easy to implement, resulting in a stable and controllable glaze gloss, free of crystal defects, and possessing a delicate skin-like texture. It ensures ultra-low gloss while also exhibiting excellent stain resistance. Attached Figure Description

[0024] Figure 1 The photograph of the ultra-low gloss skin-textured ceramic tile (glaze gloss 6.5) prepared in Example 1 under illumination shows no visible crystal spots.

[0025] Figure 2 Photograph of the glaze of the ultra-low gloss skin-textured ceramic tile prepared for Example 1.

[0026] Figure 3 The X-ray diffraction pattern of the glaze of the ultra-low gloss skin-textured ceramic tile prepared in Example 2 is shown.

[0027] Figure 4 For regular satin glaze (also known as skin glaze, gloss level 16) products, in contrast to Figure 1 In the photos taken under the same lighting conditions and angles, the circled area represents the halo formed by the glaze under light, while the center of the circle shows denser bright spots, which are the so-called crystal spots. Detailed Implementation

[0028] The present invention is further illustrated by the following embodiments. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the present invention. The following exemplary descriptions illustrate low-gloss skin-textured glaze, ultra-low-gloss skin-textured ceramic tiles, and their preparation methods.

[0029] Preparation of ceramic green bodies. The ceramic green bodies are ordinary brick green bodies with no special requirements. Ceramic green body powder can be prepared by dry pressing. The ceramic green body powder can use a conventional building ceramics formula. As an example, but not limited to, the chemical composition of the ceramic green body includes, by mass percentage: SiO2 67.8%; Al2O3 20%; Fe2O3 1.1%; TiO2 0.3%; CaO 0.3%; MgO 0.9%; K2O 2.9%; Na2O 1.9%; loss on ignition 4.8%.

[0030] The ceramic green body is dried. The drying temperature and time are standard settings in this field. After drying, the moisture content of the ceramic green body can be controlled to be 0.3–0.5 wt%.

[0031] A surface glaze is applied to the dried ceramic body. The surface glaze mainly serves to cover the body, enhance the whiteness of the brick, and provide ventilation channels during the high-temperature firing process, thus preventing glaze defects. Conventional surface glazes in this field can be used.

[0032] In some embodiments, the chemical composition of the glaze includes, by mass percentage: SiO2 49%–52%, Al2O3 26%–29%, Fe2O3 0.2%–0.5%, CaO 0.2%–0.8%, MgO 0.3%–0.6%, K2O 3.5%–5.0%, Na2O 2.0%–3.0%, ZrO2 7.0%–9.0%, and loss on ignition 3.5%–5.0%. For example, the chemical composition of the glaze includes, by mass percentage: SiO2 49.5%–51.5%, Al2O3 26.0%–29.0%, Fe2O3 0.2%–0.5%, CaO 0.2%–0.8%, MgO 0.3%–0.6%, K2O 3.5%–5.0%, Na2O 2.0%–3.0%, ZrO2 7.0%–9.0%, and loss on ignition 3.5%–5.0%.

[0033] Any surface glaze mineral composition formulation that brings the chemical composition of the surface glaze into the above-described range is applicable to this invention. The surface glaze is prepared into a glaze slurry. For example, the surface glaze mineral composition, additives, and water are ball-milled uniformly to prepare a surface glaze slurry. The additives can be any one or more of sodium tripolyphosphate, sodium carboxymethyl cellulose, sodium polyacrylate, and sodium citrate. In practical use, water can be added to the surface glaze slurry to adjust to obtain the desired final glaze slurry specific gravity.

[0034] The surface glaze can be applied by pouring or spraying. Preferably, the specific gravity of the surface glaze is 1.40–1.45 g / cm³. 3 The glaze application rate is 400-550 g / m². 2 .

[0035] Ceramic ink is printed onto the glazed surface using a ceramic inkjet printer. Ceramic ink includes, but is not limited to, color inks and / or functional inks. Functional inks include, but are not limited to, engraving inks and gloss inks.

[0036] A low-gloss, skin-textured glaze was prepared. The mineral composition of the low-gloss, skin-textured glaze includes, by mass percentage: 18%–22% sintered mullite, 6%–8% nano-silica, 7%–10% wollastonite, 10%–13% calcined talc, 2%–5% quartz, 3%–5% calcined zinc oxide, 4%–6% kaolin, 18%–22% medium-temperature frit, and 16%–20% high-temperature frit.

[0037] The initial melting temperature of the medium-temperature fused ingot is 1060–1080 °C. The chemical composition of the medium-temperature fused ingot includes, by mass percentage: SiO2 48%–50%, Al2O3 14%–18%, CaO 12%–15%, MgO 5.5%–8.0%, K2O 4.5%–8.0%, Na2O 2.5%–5.0%, BaO 1.5%–3.0%, and ZnO 5.5%–9.5%. For example, the chemical composition of a medium-temperature fused ingot includes, by mass percentage: SiO2 48.0%–49.5%, Al2O3 14.5%–16.0%, CaO 12.5%–14.0%, MgO 5.5%–6.0%, K2O 4.5%–5.0%, Na2O 2.5%–3.0%, BaO 1.5%–2.0%, and ZnO 5.5%–6.5%.

[0038] The initial melting temperature of the high-temperature fused ingot is 1120–1140°C. The chemical composition of the high-temperature fused ingot includes, by mass percentage: SiO₂ 51%–54%, Al₂O₃ 24%–26%, CaO 15%–17%, MgO 1.0%–4.0%, K₂O 3.0%–8.0%, and Na₂O 1.5%–4.0%. For example, the chemical composition of the high-temperature fused ingot includes, by mass percentage: SiO₂ 51.0%–54.0%, Al₂O₃ 24.0%–26.0%, CaO 15.0%–17.0%, MgO 1.0%–2.0%, K₂O 3.0%–4.5%, and Na₂O 1.5%–2.0%.

[0039] The particle size of sintered mullite is ≤5wt% residue on a 350-mesh sieve. The particle size of nano-silica can be D... 50 ≤80nm, D 90 ≤120nm.

[0040] This invention utilizes a novel formulation design for a skin-textured glaze: ultrafine sintered mullite powder is introduced into the glaze, uniformly dispersed at a raw material level during glaze preparation, and maintains a stable mullite crystal morphology during firing, effectively isolating crystal spots caused by spontaneous irregular crystallization on the glaze surface. Through synergistic formulation design, epidermal crystals are simultaneously and uniformly precipitated in the glaze, distributed within the lattice gaps formed by the mullite crystals, further synergistically reducing the gloss of the glaze surface. Sintered mullite powder (2Al2O3·SiO2), as a refractory crystalline phase material, has a melting point exceeding 1800℃, far higher than the firing temperature of architectural ceramic bodies and glazes. Therefore, sintered mullite powder can remain stably present in crystalline form throughout the firing process, as confirmed by the detection of mullite crystals in the X-ray diffraction analysis results of the glaze surface after firing. Thus, the ultrafine sintered mullite powder introduced into the glaze raw materials is uniformly dispersed at a raw material level in the glaze slurry preparation stage and remains stable throughout the entire glaze layer during firing, forming a stable dispersion lattice. According to the principles of materials physicochemistry, due to the periodic arrangement of crystals, crystals of different chemical compositions and types have different periodic arrangement rules, thus exhibiting mutual crystallization inhibition effects. Therefore, labradorite (Na... 1.92 Ca 2.08 Si 10 Al6O 32 Crystals can only precipitate within the lattice formed by mullite crystals, which isolates the spontaneous irregular crystallization on the glaze surface at the microscopic level, fundamentally preventing the formation of crystal spots. Using nano-silica powder improves the rheological properties of the glaze slurry, significantly increasing its viscosity and stability at the same weight, reducing the impact of ink color variations on the glaze surface smoothness, resulting in a smoother glaze surface after firing. It also helps the mullite powder to disperse stably and evenly in the glaze slurry. Furthermore, the nano-effect of nano-silica promotes firing, preventing inconsistent sintering in different micro-regions of the glaze surface, which could lead to uneven glaze texture and affect the formation of a delicate, smooth finish.

[0041] In some embodiments, the chemical composition of the low-gloss skin-textured glaze includes, by mass percentage: 48%–55% SiO2, 23%–26% Al2O3, 10%–15% CaO, 3.5%–6.0% MgO, 1.5%–4.0% K2O, 0.8%–2.0% Na2O, 0.5%–2.0% BaO, and 4.5%–8.0% ZnO. For example, the chemical composition of the low-gloss skin-textured glaze includes, by mass percentage: 48.0%–50.0% SiO2, 23.5%–25.0% Al2O3, 10.5%–12.5% ​​CaO, 3.5%–5.0% MgO, 1.5%–2.0% K2O, 0.8%–1.2% Na2O, 0.5%–1.0% BaO, and 4.5%–6.0% ZnO.

[0042] The patent in patent publication number CN112723747B uses mullite as a high-temperature raw material in the base glaze to increase the initial melting temperature of the base glaze and prevent the inkjet pattern particles printed on the surface of the base glaze from shifting during the firing process due to the low initial melting temperature of the base glaze. It will not affect the skin-textured glaze layer on the surface.

[0043] A low-gloss skin-textured glaze is prepared into a glaze slurry. For example, the mineral composition, additives, and water of the low-gloss skin-textured glaze are ball-milled to homogenize and prepare a low-gloss skin-textured glaze slurry. The additives can be any one or more of sodium tripolyphosphate, sodium carboxymethyl cellulose, sodium polyacrylate, and sodium citrate. In practical use, water can be added to the low-gloss skin-textured glaze slurry to adjust to the desired specific gravity. The fineness of the low-gloss skin-textured glaze slurry can be 0.25wt% to 0.4wt% residue on a 325-mesh sieve.

[0044] Low-gloss skin-textured glazes can be applied by pouring or spraying. In the case of pouring, the specific gravity of the low-gloss skin-textured glaze is 1.72–1.80 g / cm³. 3 The glaze application amount is 540-580 g / m². 2 In the case of a spray glaze process, the specific gravity of a low-gloss, skin-textured glaze is 1.55–1.65 g / cm³. 3 The glaze application amount is 625-700 g / m². 2 .

[0045] The body is coated with a low-gloss, skin-textured glaze and fired to produce ultra-low-gloss, skin-textured ceramic tiles. The firing process takes place in a roller kiln at 1140–1160℃ for 50–70 minutes.

[0046] After firing, the edges are ground and graded.

[0047] The surface gloss of the ultra-low gloss skin-textured ceramic tile ranges from 5.5 to 8 degrees.

[0048] The following examples further illustrate the present invention in detail. It should also be understood that the following examples are only for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention are within the scope of protection of the present invention. The specific process parameters, etc., in the following examples are merely examples within a suitable range; that is, those skilled in the art can make appropriate selections within the appropriate range based on the description herein, and are not intended to be limited to the specific values ​​in the examples below.

[0049] Example 1

[0050] The preparation method of ultra-low gloss skin-textured ceramic tiles includes the following steps:

[0051] Step 1. Dry press the powder into a blank and dry the blank.

[0052] Step 2. Apply a top coat of glaze to the dried body. The chemical composition of the top coat of glaze includes, by mass percentage: SiO2 51.95%, Al2O3 27.6%, Fe2O3 0.3%, CaO 0.5%, MgO 0.45%, K2O 4.2%, Na2O 2.5%, ZrO2 8.2%, and loss on ignition 4.3%. The top coat of glaze is applied by spraying. The specific gravity of the top coat of glaze is 1.40 g / cm³. 3 Glazing amount is 550g / m 2 .

[0053] Step 3. Use a ceramic inkjet printer to print a pattern in regular ink onto the glazed surface.

[0054] Step 4. Inkjet print engraving ink onto the lines of the regular ink pattern. The grayscale of the engraving ink pattern channel is 80%.

[0055] Step 5. Apply a low-gloss skin-textured glaze to the surface of the blank after inkjet printing and engraving. The mineral composition of the low-gloss skin-textured glaze includes, by mass percentage: 20% sintered mullite, 8% nano-silica, 10% wollastonite, 10% calcined talc, 5% quartz powder, 5% calcined zinc oxide, 4% kaolin, 20% medium-temperature frit, and 18% high-temperature frit. The chemical composition of the medium-temperature frit includes, by mass percentage: 48.5% SiO2, 16.0% Al2O3, 13.5% CaO, 5.8% MgO, 4.8% K2O, 2.9% Na2O, 2.0% BaO, and 6.5% ZnO. The chemical composition of the high-temperature frit includes, by mass percentage: 52.3% SiO2, 24.5% Al2O3, 16.7% CaO, 1.4% MgO, 3.6% K2O, and 1.5% Na2O. The chemical composition of the low-gloss skin-textured glaze includes, by mass percentage: SiO2 50.0%, Al2O3 23.9%, CaO 12.5%, MgO 3.93%, K2O 1.94%, Na2O 0.99%, BaO 0.84%, and ZnO 5.9%. The low-gloss skin-textured glaze is applied using a bell-shaped glazing process. The specific gravity of the low-gloss skin-textured glaze is 1.78 g / cm³. 3 The glaze application amount is 566g / m². 2 .

[0056] Step 6. Firing the body with the low-gloss, skin-textured glaze in a roller kiln. The firing temperature is 1150℃, and the firing cycle is 60 minutes.

[0057] Step 7. After firing, perform edge grinding and grading.

[0058] Figure 1 The ultra-low gloss skin-textured ceramic tile (glaze gloss 6.5) prepared in Example 1 and Comparative Example 3 are photographed under the same lighting and angle conditions. It can be seen that the halo formed within the circle is uniformly diffused and soft, with no visible crystal spots.

[0059] Figure 2 Photograph of the ultra-low gloss, skin-textured ceramic tile glaze prepared for Example 1. The surface quality is good.

[0060] Tested according to GB / T 13891-2008 "Method for Determination of Specular Gloss of Building Facing Materials". The gloss of the glaze is 6.5 degrees.

[0061] Tested according to GB / T 3810.14-2016 "Test Methods for Ceramic Tiles - Part 14: Determination of Stain Resistance". The glaze stain resistance level is 5.

[0062] Surface roughness was tested on the glaze. The surface roughness Ra of the sample in this embodiment is 0.49 μm. Compared with the surface roughness Ra of conventional satin glaze products (0.78 μm), the glaze surface is significantly smoother and has a good skin-like texture.

[0063] Example 2

[0064] The preparation method of ultra-low gloss skin-textured ceramic tiles includes the following steps:

[0065] Step 1. Dry press the powder into a blank and dry the blank.

[0066] Step 2. Apply a top coat of glaze to the dried body. The chemical composition of the top coat of glaze includes, by mass percentage: SiO2 49.5%, Al2O3 28.4%, Fe2O3 0.26%, CaO 0.38%, MgO 0.36%, K2O 5.0%, Na2O 2.3%, ZrO2 8.9%, and loss on ignition 4.9%. The top coat of glaze is applied by spraying. The specific gravity of the top coat of glaze is 1.45 g / cm³. 3 Glazing amount is 500g / m 2 .

[0067] Step 3. Use a ceramic inkjet printer to print a pattern in ordinary ink on the surface of the glazed body.

[0068] Step 4. Apply a low-gloss skin-textured glaze to the surface of the blank after inkjet printing with regular ink. The mineral composition of the low-gloss skin-textured glaze includes, by mass percentage: 22% sintered mullite, 6% nano-silica, 8% wollastonite, 12% calcined talc, 4% quartz powder, 4% calcined zinc oxide, 5% kaolin, 22% medium-temperature frit, and 17% high-temperature frit. The chemical composition of the medium-temperature frit includes, by mass percentage: 49.5% SiO2, 15.3% Al2O3, 13.7% CaO, 6.0% MgO, 5.0% K2O, 2.6% Na2O, 1.7% BaO, and 6.2% ZnO. The chemical composition of the high-temperature frit includes, by mass percentage: 53.2% SiO2, 24.2% Al2O3, 15.2% CaO, 1.7% MgO, 3.9% K2O, and 1.8% Na2O. The chemical composition of the low-gloss skin-textured glaze includes, by mass percentage: SiO2 49.3%, Al2O3 25.0%, CaO 11.8%, MgO 4.87%, K2O 1.82%, Na2O 1.18%, BaO 0.93%, and ZnO 5.1%. The low-gloss skin-textured glaze is applied using a spray glazing process. The specific gravity of the low-gloss skin-textured glaze is 1.62 g / cm³. 3 The amount of glaze applied is 670g / m². 2 .

[0069] Step 5. Firing the body with the low-gloss, skin-textured glaze in a roller kiln. The firing temperature is 1160℃, and the firing cycle is 70 minutes.

[0070] Step 6. After firing, perform edge grinding and grading.

[0071] Figure 3 The image shows the X-ray diffraction pattern of the ultra-low gloss, skin-textured ceramic tile glaze prepared in Example 2. According to the X-ray diffraction phase analysis, the phases present on the glaze surface are mullite and labradorite. Mullite was introduced into the formulation, while labradorite precipitated during firing. This indicates that the ultrafine sintered mullite powder introduced into the glaze maintained a stable mullite crystal morphology during firing, effectively isolating crystal spots caused by spontaneous irregular crystallization on the glaze surface. Furthermore, labradorite crystals simultaneously precipitated in the glaze, distributing within the gaps formed by the mullite crystals on the glaze surface, further synergistically reducing the gloss of the glaze surface.

[0072] Tests showed that the glaze has a gloss level of 5.5 and a stain resistance level of 5.

[0073] The surface roughness of the glaze was tested. In this embodiment, the surface roughness of the glaze Ra = 0.42 μm, which provides a good feel to the skin.

[0074] Comparative Example 1

[0075] In Example 2, the nano-silica powder in the low-gloss skin-textured glaze was replaced with an equal amount of quartz, and the rest was prepared using the same process.

[0076] The measured gloss of the glaze was 8.5 degrees, the surface roughness Ra = 0.93 μm, and the skin-touch feel was reduced.

[0077] Comparative Example 2

[0078] In Example 1, the amount of sintered mullite in the low-gloss skin-textured glaze was adjusted to 15%, wollastonite to 12%, and medium-temperature frit to 23%, while the rest were prepared using the same process.

[0079] After firing, the glaze gloss was measured to be 13 degrees, and crystal spots were observed on the glaze surface when viewed against the light. This is because the amount of sintered mullite was small, resulting in a large spacing between the dispersed lattice points in the glaze. In addition, there was still irregular crystallization of labradorite between the lattice points, which caused the formation of crystal spots.

[0080] Comparative Example 3

[0081] The low-gloss skin-textured glaze in Example 1 was replaced with a conventional satin glaze. The raw material composition of the satin glaze includes, by mass percentage: 40% potassium feldspar, 15% barium carbonate, 7% kaolin, 3% calcined kaolin, 6% calcined zinc oxide, 7% calcite, 10% dolomite, and 12% calcined talc.

[0082] Figure 4 This is a photo of a regular satin glaze (also known as skin glaze, gloss level 16) product under light. The circled area is the halo formed on the glaze surface under light. It can be seen that the center of the circle shows a relatively dense number of bright spots, which are the so-called crystal spots. These are caused by the irregular precipitation of crystal phases in the glaze. These crystal spots produce an uneven appearance under light, which to some extent reduces the quality of the product.

[0083] Comparative Example 4

[0084] The sintered mullite (2Al2O3·SiO2) in Example 1 was replaced with equal amounts of calcined alumina (Al2O3) and quartz (SiO2), while the rest remained unchanged.

[0085] After firing, the glaze's gloss was measured at 18 degrees, with low transparency and poor color. This is because sintered mullite, a single crystal containing both alumina and silica, is introduced into the glaze and remains stable during firing, maintaining high transparency. When it is separated into equal amounts of calcined alumina (Al2O3) and quartz (SiO2), the firing temperature in the kiln is far below the mullite's formation temperature, fundamentally altering the glaze's crystallization path and chemical changes. This results in poorer color, increased gloss, and a lack of skin-like texture.

Claims

1. A low-gloss, skin-textured glaze, characterized in that, The mineral composition of the low-gloss skin-textured glaze includes, by mass percentage: 18%–22% sintered mullite, 6%–8% nano-silica, 7%–10% wollastonite, 10%–13% calcined talc, 2%–5% quartz, 3%–5% calcined zinc oxide, 4%–6% kaolin, 18%–22% medium-temperature frit, and 16%–20% high-temperature frit.

2. The low-gloss skin-textured glaze according to claim 1, characterized in that, The initial melting temperature of the medium-temperature fused block is 1060–1080 °C; preferably, the chemical composition of the medium-temperature fused block includes, by mass percentage: SiO2 48%–50%, Al2O3 14%–18%, CaO 12%–15%, MgO 5.5%–8.0%, K2O 4.5%–8.0%, Na2O 2.5%–5.0%, BaO 1.5%–3.0%, ZnO 5.5%–9.5%.

3. The low-gloss skin-textured glaze according to claim 1 or 2, characterized in that, The initial melting temperature of the high-temperature molten block is 1120–1140°C; preferably, the chemical composition of the high-temperature molten block includes, by mass percentage: 51%–54% SiO2, 24%–26% Al2O3, 15%–17% CaO, 1.0%–4.0% MgO, 3.0%–8.0% K2O, and 1.5%–4.0% Na2O.

4. The low-gloss skin-textured glaze according to any one of claims 1 to 3, characterized in that, The chemical composition of the low-gloss skin-textured glaze includes, by mass percentage: SiO2 48%–55%, Al2O3 23%–26%, CaO 10%–15%, MgO 3.5%–6.0%, K2O 1.5%–4.0%, Na2O 0.8%–2.0%, BaO 0.5%–2.0%, and ZnO 4.5%–8.0%.

5. The low-gloss skin-textured glaze according to any one of claims 1 to 4, characterized in that, The low-gloss skin-textured glaze uniformly precipitates labradorite crystals after firing, and the labradorite crystals are distributed in the lattice gaps formed by the mullite crystals.

6. A method for preparing ultra-low gloss skin-textured ceramic tiles, characterized in that, The preparation method includes: Apply a surface glaze to the body; Ceramic ink is inkjet printed onto the surface of the glazed body. A low-gloss skin-textured glaze according to any one of claims 1 to 5 is applied to the surface of the blank after inkjet printing ceramic ink. The body with the low-gloss skin-textured glaze is fired to obtain ultra-low gloss skin-textured ceramic tiles.

7. The preparation method according to claim 6, characterized in that, The low-gloss skin-textured glaze is applied by either pouring or spraying; when using the pouring process, the specific gravity of the low-gloss skin-textured glaze is 1.72–1.80 g / cm³. 3 The glaze application amount is 540-580 g / m². 2 When using a spray glazing process, the specific gravity of a low-gloss, skin-textured glaze is 1.55–1.65 g / cm³. 3 The glaze application amount is 625-700 g / m². 2 .

8. The preparation method according to claim 6 or 7, characterized in that, The ceramic ink includes colored ink and / or functional ink; functional ink includes engraving ink or glossy ink.

9. The preparation method according to any one of claims 6 to 8, characterized in that, The chemical composition of the glaze includes, by mass percentage: SiO2 49%–52%, Al2O3 26%–29%, Fe2O3 0.2%–0.5%, CaO 0.2%–0.8%, MgO 0.3%–0.6%, K2O 3.5%–5.0%, Na2O 2.0%–3.0%, ZrO2 7.0%–9.0%, and loss on ignition 3.5%–5.0%. Preferably, the glaze is applied by pouring or spraying. The specific gravity of the glaze is 1.40–1.45 g / cm³. 3 The glaze application rate is 400-550 g / m². 2 .

10. The preparation method according to any one of claims 6 to 9, characterized in that, The firing temperature is 1140–1160℃, and the firing cycle is 50–70 minutes.

11. Ultra-low gloss skin-textured ceramic tiles, characterized in that... The ultra-low gloss skin-textured ceramic tile is obtained by the preparation method according to any one of claims 6 to 10.

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