Sanitary ware

Abstract

To provide sanitary ceramics endowed with not only outstanding antifouling capabilities but also an exceptional texture that merges both glossy and matte finishes.SOLUTION: Sanitary ceramics comprise a substrate and a surface layer. The surface layer comprises polycrystals. The polycrystals comprise TiO2, ZrO2, and Ti2ZrO6. The surface layer has a 60° surface gloss of 60 or more.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] This invention relates to sanitary ware. More specifically, it relates to sanitary ware that possesses both a good gloss and a matte finish. [Background technology]

[0002] Sanitary ware such as toilets and washbasins are elements that make up living spaces such as toilets and washrooms. Therefore, in addition to their inherent performance such as stain resistance, ease of cleaning, and strength, their design has also become a requirement in recent years. Generally, a glaze layer is applied to the surface of sanitary ware, which gives the surface a glossy appearance. On the other hand, sanitary ware with a matte finish that suppresses gloss has also been proposed.

[0003] For example, Japanese Patent Publication No. 2018-104272 (Patent Document 1) discloses a matte-finish member that has a matte appearance (i.e., low gloss) with a 60° gloss of 20 or less, while still having good stain resistance, by making the surface properties of the glassy layer provided on the surface of the substrate to a specific roughness.

[0004] In recent years, with the increasing diversification of sanitary ware designs, particularly the growing demand for aesthetic appeal, there has been a trend towards developing sanitary ware that possesses not only essential performance features such as stain resistance, but also new design elements that appeal to aesthetic sensibilities. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2018-104272 [Overview of the project] [Problems that the invention aims to solve]

[0006] The present inventors have now found a sanitary ceramic product that combines inherently required performances such as antifouling property with a novel and excellent texture (aesthetic appearance). In particular, they have found a novel structure of a sanitary ceramic product that has a glossy feeling while also having a matte feeling. That is, they have found that by allowing a polycrystalline body containing a plurality of types of specific metal oxides to exist on the surface and further controlling the 60° glossiness of the surface within a specific range, a sanitary ceramic product having both good antifouling property and a novel excellent texture that combines both glossy feeling and matte feeling can be obtained. The present invention is based on such findings.

[0007] Accordingly, an object of the present invention is to provide a sanitary ceramic product having both good antifouling property and an excellent texture that combines both glossy feeling and matte feeling. Means for Solving the Problem

[0008] The sanitary ceramic product according to the present invention is: comprising a base material and a surface layer, wherein the surface layer contains a polycrystalline body, the polycrystalline body contains TiO2, ZrO2 and Ti2ZrO6, and the 60° glossiness of the surface of the surface layer is 60 or more. Effects of the Invention

[0009] According to the present invention, there is provided a sanitary ceramic product having both good antifouling property and an excellent texture that combines both glossy feeling and matte feeling. Brief Description of Drawings

[0010] [Figure 1] FIG. 1 is a schematic diagram showing an example of the sanitary ceramic product according to the present invention. [Figure 2] FIG. 2 is an FE-SEM image of the surface of the sanitary ceramic product of Example 1. [Figure 3] FIG. 3 is an FE-SEM image of the surface of the sanitary ceramic product of Example 2. [Figure 4] FIG. 4 is an FE-SEM image of the surface of the sanitary ceramic product of Example 3. [Figure 5] This is an FE-SEM image of the surface of the sanitary ware from Example 4. [Figure 6] This is an FE-SEM image of the surface of the sanitary ware in Comparative Example 1. [Figure 7] This is an FE-SEM image of the surface of the sanitary ware in Comparative Example 2. [Figure 8] This is an X-ray diffraction spectrum diagram of the surface of the sanitary ware from Example 1. [Figure 9] This is an X-ray diffraction spectrum diagram of the surface of the sanitary ware from Example 2. [Figure 10] This is an X-ray diffraction spectrum diagram of the surface of the sanitary ware from Example 3. [Figure 11] This is an X-ray diffraction spectrum diagram of the surface of the sanitary ware from Example 4. [Figure 12] This is an X-ray diffraction spectrum diagram of the surface of the sanitary ware of Comparative Example 1. [Figure 13] This is an X-ray diffraction spectrum diagram of the surface of the sanitary ware in Comparative Example 2. [Modes for carrying out the invention]

[0011] Sanitary ware In this invention, "sanitary ware" means ceramic products used in bathrooms, toilets, powder rooms, washrooms, or kitchens. Specifically, it means toilets, urinals, toilet bowls, toilet tanks, washbasins, handwashing sinks, etc.

[0012] The sanitary ware according to the present invention will be described with reference to Figure 1. As shown in Figure 1(a), the sanitary ware 10 according to the present invention comprises a base material 1 and a surface layer 2. The surface layer 2 is provided on the surface of the base material 1. Figures 1(b) and 1(c) show examples of sanitary ware according to the present invention (details will be described later).

[0013] Base material In the present invention, the base material 1 may be, for example, a known sanitary ware base material. That is, a known sanitary ware base material obtained by preparing a slip from silica sand, feldspar, limestone, clay, etc. as raw materials, molding it, and firing it can be used as the base material 1.

[0014] surface layer <Composition> The surface layer 2 contains a polycrystalline material. In this invention, a polycrystalline material means a material composed of multiple types of single crystals. The single crystals contained in this polycrystalline material are inseparable. The polycrystalline material includes single crystals of titanium oxide (TiO2), single crystals of zirconium oxide (ZrO2), and single crystals of Ti2ZrO6, which is a type of composite oxide of titanium and zirconium (this characteristic of the surface layer 2 is sometimes referred to as the "specific composition"). As a result, the sanitary ware 10 can simultaneously exhibit a good gloss and matte finish.

[0015] The mechanism by which the sanitary ware 10 according to the present invention can simultaneously exhibit good gloss and matte finish is thought to be as follows: Due to the surface properties (described later) achieved by the surface layer 2 having the above-mentioned specific composition, when light is incident on the surface of the surface layer 2, a large portion of the incident light is totally reflected at the surface, resulting in a high gloss on the surface. At the same time, a portion of the incident light is diffused at the surface by Mie scattering, resulting in a good matte finish on the surface. It is thought that the simultaneous occurrence of these two phenomena makes it possible to realize a surface layer that possesses both good gloss and matte finish. It should be noted that the above explanation is merely a hypothesis, and the present invention is not limited in any way by this hypothesis.

[0016] In the present invention, the surface layer 2 may further contain either a single crystal or an amorphous material, as long as it contains a polycrystalline material, or it may further contain both a single crystal and an amorphous material. That is, in addition to a polycrystalline material containing TiO2, ZrO2, and Ti2ZrO6, the surface layer 2 may further contain at least one single crystal or amorphous material selected from single crystal or amorphous titanium oxide, single crystal or amorphous zirconium oxide, and single crystal or amorphous Ti2ZrO6. It may also further contain at least one single crystal and amorphous material selected from single crystal and amorphous titanium oxide, single crystal and amorphous zirconium oxide, and single crystal and amorphous Ti2ZrO6.

[0017] The presence of polycrystalline material in surface layer 2 can be confirmed, for example, by the following method. First, the surface of the sanitary ware 10 is photographed at an appropriate magnification using a field emission scanning electron microscope (FE-SEM) to obtain an image (hereinafter referred to as "FE-SEM image"). The presence or absence of aggregates of multiple single crystals in the FE-SEM image is checked. Next, these confirmed aggregates of single crystals are evaluated by X-ray diffraction (XRD).

[0018] By performing XRD measurements on the surface of the sanitary ware 10, it can be confirmed that the aggregate of single crystals observed in the FE-SEM image contains multiple types of single crystals, i.e., that it is a polycrystalline material. By analyzing the X-ray diffraction spectrum obtained by the XRD measurement, the crystalline phase contained in the surface layer can be identified. The XRD measurement is performed using an available XRD device, with voltage and current values ​​set to a level sufficient to identify the crystalline phase of the thin film. Furthermore, the crystalline phase is identified using the powder analysis database "ICDD Database PDF-2" (manufactured by LightStone) for analysis of the obtained X-ray diffraction spectrum. By comparing the obtained X-ray diffraction spectrum with the database, the crystalline phase contained in the surface layer can be identified.

[0019] An available XRD device can be used. For example, SmartLab (manufactured by Rigaku Corporation) can be used. The following measurement conditions can be used: X-ray generator: CuKα rays, voltage: 45kV, current: 200mA, scan axis: 2θ, X-ray incidence angle: 0.5°, scan range: 20~40°, step size: 0.02°, scan speed: 0.5° / min. This allows for the acquisition of an X-ray diffraction spectrum. The obtained X-ray diffraction spectrum is then analyzed using the powder analysis database "ICDD Database PDF-2" (manufactured by LightStone Corporation) to identify the crystalline phase.

[0020] Furthermore, the Rint TTR III (manufactured by Rigaku Corporation) can be used as the XRD device. The following measurement conditions can be used: X-ray generator: CuKα rays, voltage: 50kV, current: 300mA, scan axis: 2θ, X-ray incidence angle: 0.5°, scan range: 20~40°, step size: 0.02°, scan speed: 0.5° / min. This allows for the acquisition of an X-ray diffraction spectrum. The obtained X-ray diffraction spectrum is then analyzed using the powder analysis database "ICDD Database PDF-2" (manufactured by LightStone), as described above, to identify the crystalline phase.

[0021] This allows us to confirm that the collection of single crystals observed in the FE-SEM image contains multiple types of single crystals, i.e., it is a polycrystalline material. Furthermore, it can be confirmed that the polycrystalline material contains single crystals of TiO2, ZrO2, and Ti2ZrO6.

[0022] In the present invention, the size of the polycrystalline material is preferably 50 nm to 100 nm. This is thought to facilitate Mie scattering of incident light on the surface of the sanitary ware 10, and as a result, it is thought to be easier to produce a matte finish. In the present invention, the size of the polycrystalline material is measured by the following method. Specifically, the above FE-SEM image is analyzed using image analysis software, and 10 polycrystalline materials are randomly identified in the FE-SEM image by visual inspection. The length (nm) of the long side and short side of each of the 10 polycrystalline materials is measured. The average of the 20 measured values ​​(10 long side lengths and 10 short side lengths) is taken as the size of the polycrystalline material.

[0023] The content of the polycrystalline material in the surface layer 2 may be appropriately determined so that the surface layer 2 has both good gloss and matte finishes, but it is preferably 50% by mass or more, and more preferably 80% by mass or more. Furthermore, the respective content ratios of titanium oxide (TiO2) single crystals, zirconium oxide (ZrO2) single crystals, and Ti2ZrO6 single crystals in the polycrystalline material may be appropriately determined so that the surface layer 2 has both good gloss and matte finishes, but it is preferable to include, for example, titanium oxide (TiO2) single crystals preferably 60% by mass or more and 90% by mass or less, more preferably 67% by mass or more and 83% by mass or less, zirconium oxide (ZrO2) single crystals preferably 1% by mass or more and 20% by mass or less, more preferably 5% by mass or more and 17% by mass or less, and Ti2ZrO6 single crystals preferably 10% by mass or more and 20% by mass or more, more preferably 12% by mass or more and 17% by mass or less.

[0024] The respective content ratios of titanium dioxide (TiO2), zirconium oxide (ZrO2), and Ti2ZrO6 contained in the surface layer 2 are not particularly limited, as long as the surface layer 2 has a specific composition. According to a preferred embodiment of the present invention, the surface layer 2 contains titanium dioxide (TiO2), preferably 60% to 90% by mass, more preferably 67% to 83% by mass; zirconium oxide (ZrO2), preferably 1% to 20% by mass, more preferably 5% to 17% by mass; and Ti2ZrO6, preferably 10% to 20% by mass, more preferably 12% to 17% by mass.

[0025] In the present invention, the respective content ratios of titanium oxide (TiO2), zirconium oxide (ZrO2), and Ti2ZrO6 contained in the surface layer 2 and the polycrystalline material can be obtained from the XRD measurement described above.

[0026] In the present invention, titanium dioxide may be anatase type, rutile type, or a combination thereof. In the case of a combination, the content ratio of anatase type and rutile type titanium dioxide is preferably 99:1 to 75:25 (anatase type:rutile type), and more preferably 95:5 to 80:20.

[0027] In this invention, it is preferable that ZrO2 has an orthorhombic crystal structure. This makes it easier for the sanitary ware 10 to achieve both a good gloss and a matte finish.

[0028] <Surface texture> In the present invention, the surface layer 2 has a 60° gloss (hereinafter sometimes abbreviated as "surface gloss") of 60 or higher. This allows the surface layer 2 to exhibit good gloss. The surface gloss is preferably 95 or higher, and more preferably 150 or higher. Furthermore, it is preferable that the upper limit be 190 or lower.

[0029] In the present invention, the surface layer 2 preferably has a surface roughness (Sa) of less than 0.35 μm, more preferably 0.23 μm or less, and even more preferably 0.11 μm or less. Furthermore, the lower limit of Sa is preferable as small as possible, but preferably 0.04 μm or more, and even more preferably 0.06 μm or more. This allows the sanitary ware 10 to more reliably achieve both good gloss and matte finishes.

[0030] In this invention, the 60° gloss of the surface of surface layer 2 can be measured in accordance with JIS Z 8741:1997. As a measuring device, for example, a gloss meter (GM-268plus manufactured by Konica Minolta Corporation) can be used.

[0031] In the present invention, the surface roughness (Sa) of the surface layer 2 can be measured in accordance with JIS B 0681-2:2019.

[0032] <Spatial volume of the protruding valley (Vvv)> In this invention, the surface of surface layer 2 has a spatial volume (Vvv) of protruding valleys as defined in JIS B 0681-2:2018 of 0.06 ml / m². 2 The following is preferable. This is thought to make it easier for light reflection to occur on the surface of the sanitary ware, and as a result, the surface of the sanitary ware is thought to be more likely to exhibit a high gloss.

[0033] Vvv is a parameter that represents the surface properties of an object in three dimensions. Specifically, it is a volume parameter that quantifies the size of the protruding valleys on the object's surface. When measuring Vvv, the load area ratio that separates the core from the protruding valleys is specified to an appropriate percentage.

[0034] <film thickness> In the present invention, the thickness of the surface layer 2 may be appropriately determined considering the various characteristics required of the sanitary ware 10, but it is preferably 50 nm to 100 nm. This makes it possible to create a dense and highly durable surface layer. More preferably, the thickness of the surface layer 2 is 50 nm to 70 nm.

[0035] The thickness of surface layer 2 can be measured, for example, by the following method: A cross-section of the sanitary ware is photographed at an appropriate magnification using a field emission scanning electron microscope (FE-SEM) to obtain an FE-SEM image. The FE-SEM image is analyzed using image analysis software, and 10 random points representing the thickness of the surface layer are identified visually within the FE-SEM image. The average thickness of these 10 points can be used as the thickness of the surface layer of the sanitary ware.

[0036] glaze layer In the present invention, another layer may be provided between the base material 1 and the surface layer 2. For example, as shown in Figure 1(b), a glaze layer 3 may be provided between the base material 1 and the surface layer 2. That is, in one embodiment of the present invention, the sanitary ware 10 comprises a base material 1, a glaze layer 3, and a surface layer 2. In other words, it comprises a base material 1, a glaze layer 3 provided on the surface of the base material 1, and a surface layer 2 provided on the surface of the glaze layer 3. In the present invention, the composition of the glaze layer 3 can be, for example, one of the compositions shown in the table below.

[0037] [Table 1]

[0038] Middle class In the present invention, another layer may be provided between the glaze layer 3 and the surface layer 2. For example, as shown in Figure 1(c), an intermediate layer 4 may be provided between the glaze layer 3 and the surface layer 2. That is, in one embodiment of the present invention, the sanitary ware 10 comprises a base material 1, a glaze layer 3, an intermediate layer 4, and a surface layer 2. In other words, it comprises a base material 1, a glaze layer 3 provided on the surface of the base material 1, an intermediate layer 4 provided on the surface of the glaze layer 3, and a surface layer 2 provided on the surface of the intermediate layer 4. The intermediate layer 4 may, for example, be for increasing the durability of the surface layer 2. Alternatively, the intermediate layer 4 may be a glaze layer separate from the glaze layer 3.

[0039] The intermediate layer 4 may contain some of the metal oxides found in the glaze layer 3 and the surface layer 2, for example, silica and titanium oxide and / or zirconium oxide. In this case, the silica content is in the range of 98% to 85% by mass, with a preferred upper limit of 95% by mass and a preferred lower limit of 90% by mass. The titanium oxide and zirconium oxide content, when both are included, is in the range of 2% to 15% by mass, with a preferred upper limit of 10% by mass and a preferred lower limit of 5% by mass.

[0040] In the present invention, the thickness of the intermediate layer 4 may be appropriately determined within a range that enhances the durability of the surface layer 2, and is preferably 10 nm or more and 100 nm or less.

[0041] Manufacturing methods for sanitary ware <Preparation of base material> First, prepare the base material 1. As mentioned above, the base material 1 may be a known base material for sanitary ware. For example, a slip can be prepared using silica sand, feldspar, limestone, clay, etc. as raw materials, and this can be molded, for example, by a slip casting method, and then fired to obtain the base material 1.

[0042] <Formation of the surface layer> Next, a surface layer 2 is formed on the surface of the substrate 1. According to one aspect of the present invention, the surface layer 2 can be formed by applying, preferably coating, a coating solution containing titanium oxide, zirconium oxide, and Ti2ZrO6, or precursors thereof, to the surface of the substrate 1, and then firing it. The firing conditions may be determined as appropriate, but the firing temperature is preferably, for example, 900°C or higher and less than 960°C, and more preferably 900°C or higher and 954°C or lower. By firing within the above temperature range, the growth of the polycrystalline material, i.e., the size of the crystal grains, can be controlled within a range that enables the realization of specific surface properties of the surface layer 2. The firing time may be determined as appropriate within the above firing temperature range, but for example, 10 to 45 hours is preferred.

[0043] Titanium alkoxides and titanium chelates can be suitably used as precursors to titanium dioxide. Titanium alkoxides are basically represented by the general formula: Ti(OR)4 and are not limited as long as they produce titanium dioxide by hydrolysis. Part of (OR) in the formula may be substituted with acetylacetonate (C5H7O2) or ethyl acetoacetate (C6H9O3). According to a preferred embodiment of the present invention, the R portion of the organic group of the alkoxide (RO-) is lower (preferably C 1-6 ) is an alkyl group. Preferred specific examples include tetraethoxytitanium, tetraisopropoxytitanium, tetra-n-propoxytitanium, tetrabutoxytitanium, tetramethoxytitanium, titanium diisopropoxybis(acetylacetonate), titanium diisopropoxybis(ethylacetoacetate), and mixtures thereof. As for titanium chelates, for example, titanium tetraacetylacetonate is used.

[0044] As precursors to zirconium oxide, zirconium alkoxides and zirconium chelates can be suitably used. Zirconium alkoxides are basically represented by the general formula: Zr(OR)4 and are not limited as long as they produce zirconium oxide by hydrolysis. Part of (OR) in the formula may be substituted with acetylacetonate (C5H7O2) or ethyl acetoacetate (C6H9O3). According to a preferred embodiment of the present invention, the zirconium alkoxide is an alkoxide (RO - The organic group R portion of ) is lower (preferably C 2-6 ) is an alkyl group. Preferred specific examples include zirconium tetraethoxide, zirconium tetraisopropoxide, zirconium tetrabutoxide, zirconium triputoxymonoacetylacetonate, zirconium dibutoxybis(ethylacetoacetate), zirconium monobutoxyacetylacetonate bis(ethylacetoacetate), and mixtures thereof. As for zirconium chelates, zirconium tetraacetylacetonate is an example.

[0045] Suitable solvents for the coating solution include alcohols such as ethanol, isopropanol, and n-butanol; cellosolves such as methyl cellosolve and butyl cellosolve; aromatic hydrocarbons such as toluene and xylene; and esters such as ethyl acetate and butyl acetate. However, the solvent is not particularly limited as long as it can dissolve titanium alkoxide and zirconium alkoxide.

[0046] The coating liquid may be applied to the surface of the substrate 1 by commonly used methods such as brush application, roller application, spray application, roll coater, flow coater, dip coating, pour application, or screen printing.

[0047] <Formation of the glaze layer> When a glaze layer 3 is provided between the base material 1 and the surface layer 2, the sanitary ware 10 is manufactured by forming the glaze layer 3 and the surface layer 2 on the base material 1. The glaze layer 3 can be formed by applying, preferably coating, the glaze already described onto the base material 1 and then firing it. The surface layer 2 can be formed by applying, preferably coating, a coating solution containing titanium oxide, zirconium oxide, and Ti2ZrO6, or precursors thereof, onto the glaze layer 3 and then firing it. Here, the firing for forming the glaze layer 3 and the surface layer 2 may be performed separately or simultaneously. In the present invention, it is preferable that the glaze layer 3 and the surface layer 2 are formed by applying the glaze and the above coating solution onto the base material 1 and then firing them together. It is preferable that the firing conditions used for forming the surface layer, as described earlier, are used for the firing conditions.

[0048] The composition of the glaze for forming the glaze layer 3 is not limited as long as the surface gloss and surface roughness of the surface layer 2 can be achieved. In the present invention, a mixture of natural mineral particles such as silica sand, feldspar, and limestone can be used as the glaze raw material. The glaze layer 3 may contain pigments, such as cobalt compounds and iron compounds. The glaze layer 3 may also contain emulsifiers, such as zirconium silicate and tin oxide.

[0049] In the present invention, examples of glaze raw materials include feldspar in an amount of 10 wt% to 30 wt%, silica sand in an amount of 15 wt% to 40 wt%, calcium carbonate in an amount of 10 wt% to 25 wt%, corundum, talc, dolomite, and zinc oxide in amounts of 10 wt% or less each, and an emulsion and pigment in a total amount of 15 wt% or less. In the present invention, a glaze having, for example, the following composition can be used.

[0050] [Table 2]

[0051] <Formation of the middle layer> When an intermediate layer 4 is provided between the glaze layer 3 and the surface layer 2, the sanitary ware 10 is manufactured by forming the glaze layer 3, the intermediate layer 4, and the surface layer 2 on a base material 1. The intermediate layer 4 can be manufactured by applying, preferably coating, a coating solution containing silica and titanium oxide and / or zirconium oxide, or precursors thereof, onto the glaze layer 3, and then firing it. According to a preferred embodiment of the present invention, examples of silica precursors include alkyl silicates such as methyl silicate and ethyl silicate, and polymers thereof. Furthermore, as precursors of titanium oxide and zirconium oxide, those exemplified for the surface layer can preferably be used. The formation of the glaze layer 3 on the base material 1 is as already described. The surface layer 2 can be formed by applying, preferably coating, a coating solution containing titanium oxide, zirconium oxide, and Ti2ZrO6, or precursors thereof, onto the intermediate layer 4, and then firing it. Here, the firing for the formation of the glaze layer 3, the intermediate layer 4, and the surface layer 2 may be performed separately or simultaneously. In the present invention, the glaze layer 3, the intermediate layer 4, and the surface layer 2 are preferably formed by applying glaze, a coating liquid for forming the intermediate layer 4, and a coating liquid for forming the surface layer 2 onto the substrate 1, and then firing them together. The firing conditions are preferably the same as those used for forming the surface layer, as described above. [Examples]

[0052] The present invention will be specifically described based on the following examples, but the present invention is not limited to these examples.

[0053] preparation <Preparation of coating solution for intermediate layer formation> Silica alkoxide (alkoxysilane hydrolysis solution, manufactured by Colcoat Co., Ltd.) and titanium alkoxide (titanium diisopropoxybis(acetylacetonate), NDH-510C, manufactured by Nippon Soda Co., Ltd.) were mixed so that the weight ratio of solids after calcination was 5% titanium dioxide and 95% silica. Next, this mixture was diluted with a mixed solvent of 2-propanol (80%) and methyl cellosolve (20%) so that the solids after calcination was 0.5%, and the diluted solution was mixed with a stirrer. The resulting mixture was left to stand for more than one hour and used as a coating solution for forming the intermediate layer.

[0054] <Preparation of coating solution for surface layer formation> Titanium alkoxide (compound name: titanium diisopropoxybis(acetylacetonate), trade name: NDH-510C, manufactured by Nippon Soda Co., Ltd.) and zirconium alkoxide (compound name: zirconium triputoxymonoacetylacetonate, trade name: Orgatics ZC-540, manufactured by Matsumoto Fine Chemical Co., Ltd.) were mixed so that the weight ratio of the solids after calcination was 60% to 90% by mass for titanium oxide, 1% to 20% by mass for zirconium oxide, and 10% to 20% by mass for Ti2ZrO6. Next, this mixture was diluted with a mixed solvent of 2-propanol (80%) and methyl cellosolve (20%) so that the solids after calcination was 0.5%, and the diluted solution was mixed with a stirrer. The resulting mixture was left to stand for more than one hour and used as a coating solution for surface layer formation.

[0055] Manufacturing of sanitary ware The prepared ceramic raw materials were cast to obtain a base, and glaze was applied to the surface of this base using a hand spray gun (F100, manufactured by Meiji Machine Works Co., Ltd.). Subsequently, the ceramic tiles were fired for 24 hours in a tunnel kiln set to a maximum temperature of 1180°C, with the temperature gradually rising and falling to obtain the ceramic tiles. The glaze used had a composition within the following range.

[0056] [Table 3]

[0057] Formation of the intermediate layer An intermediate layer forming coating liquid was applied to the surface of the ceramic tile using a hand spray gun (F100, manufactured by Meiji Machine Works Co., Ltd.), with the application amount controlled so that the film thickness after firing would be 50 nm.

[0058] Formation of the surface layer On the surface of ceramic tiles coated with an intermediate layer forming coating liquid, a surface layer forming coating liquid was applied using a hand spray gun (F100, manufactured by Meiji Machine Works Co., Ltd.), with the application amount controlled so that the film thickness after firing would be 50-100 nm.

[0059] firing The ceramic tiles obtained as described above were coated with an intermediate layer forming coating liquid and a surface layer forming coating liquid. These were then fired for 24 to 27 hours in a high-temperature electric furnace (FUH732DA, manufactured by ADVANTEC Corporation) with a maximum temperature of 900°C to 950°C, while gradually increasing and decreasing the temperature, to obtain the sanitary ware of Examples 1 to 4 and Comparative Examples 1 to 2. The temperature inside the electric furnace was set to less than 900 to 960°C for the production of the sanitary ware of Examples 1 to 4, and outside the above temperature range for the production of the sanitary ware of Comparative Examples 1 to 2.

[0060] evaluation The sanitary ware of Examples 1-4 and Comparative Examples 1-2 were evaluated as follows.

[0061] Confirmation that the surface layer contains polycrystalline material. The surface of each sanitary ceramic was photographed at a magnification of 50,000 to 100,000 times using a field emission scanning electron microscope (FE-SEM, S-4800 manufactured by Hitachi High-Technologies Corporation), to obtain images (hereinafter referred to as "FE-SEM images"). The presence or absence of aggregates of a plurality of single crystals in the FE-SEM images was checked, and the confirmed aggregates of single crystals were determined to be polycrystals. FE-SEM images of the surfaces of the sanitary ceramics of Examples 1 to 4 and Comparative Examples 1 to 2 are shown in Figures 2 to 7.

[0062] Measurement of the size of polycrystalline materials Each FE-SEM image was evaluated using image analysis software WinROOF (manufactured by Mitani Corporation). Ten polycrystals were randomly identified visually in the FE-SEM images. The lengths (in nm) of the long side and short side of each of the ten polycrystals were measured. The average value of a total of 20 measured values, including 10 measured long side lengths and 10 measured short side lengths, was taken as the size of polycrystals contained in the surface of the sanitary ceramics of Examples 1 to 4 and Comparative Examples 1 to 2. The results are shown in Table 4.

[0063] Polycrystalline material is TiO 2 , ZrO 2 and Ti 2 ZrO 6 Confirmation that it includes XRD measurement was performed on the surface of each sanitary ceramic. <XRD Measurement> · Example 1 Rint TTR III (manufactured by Rigaku Corporation) was used as the XRD apparatus. The following measurement conditions were used: X-ray generator: CuKα radiation, voltage: 50 kv, current value: 300 mA, scan axis: 2θ, X-ray incident angle: 0.5°, scan range: 20 to 40°, step width: 0.02°, scan speed: 0.5° / min. An X-ray diffraction spectrum was obtained thereby. · Examples 2 to 4 · Comparative Examples 1 to 2 A SmartLab (manufactured by Rigaku Corporation) was used as the XRD system. The following measurement conditions were used: X-ray generator: CuKα rays, voltage: 45kV, current: 200mA, scan axis: 2θ, X-ray incidence angle: 0.5°, scan range: 20~40°, step size: 0.02°, scan speed: 0.5° / min. An X-ray diffraction spectrum was obtained using these conditions. <Identification of crystalline phases> The obtained X-ray diffraction spectrum was analyzed using the powder analysis database "ICDD Database PDF-2" (LightStone Corporation) to identify the crystalline phase. This confirmed that the aggregate of single crystals observed in the FE-SEM image contained multiple types of single crystals, i.e., it was a polycrystalline material. Furthermore, it was confirmed that the polycrystalline material contained single crystals of TiO2, ZrO2, and Ti2ZrO6. Figures 8-13 show the X-ray diffraction spectra of the surfaces of the sanitary ware from Examples 1-4 and Comparative Examples 1-2.

[0064] Measurement of surface layer thickness Cross-sections of each sanitary ware were photographed at 50,000 to 100,000x magnification using a field emission scanning electron microscope (FE-SEM, Hitachi High-Technologies S-4800) to obtain FE-SEM images. Each FE-SEM image was analyzed using the image analysis software WinROOF (Mitani Corporation), and 10 random points representing the thickness of the surface layer were identified visually within the FE-SEM image. The average thickness of these 10 points was used as the surface layer thickness of the sanitary ware in Examples 1-4 and Comparative Examples 1-2. The results are shown in Table 4.

[0065] Sensory evaluation of glossiness and matte finish Ten people visually inspected the surface of each sanitary ware piece and evaluated whether it had a glossy or matte finish. A piece was judged to have a glossy finish if six or more people evaluated it as glossy, and a piece was judged to have a matte finish if six or more people evaluated it as matte. The results are shown in Table 4.

[0066] Measurement of gloss The 60° glossiness of the surface of each sanitary ware was measured with a gloss meter (GM-268plus, manufactured by Konica Minolta, Inc.) in accordance with JIS Z 8741:2017. The results are shown in Table 4.

[0067] Measurement of surface roughness (Sa) The surface roughness (Sa) of each sanitary ware was measured in accordance with JIS B 0681-2:2019. The measurement conditions were set to S-filter 0.00025 mm and L-filter 0.8 mm. The results are shown in Table 4.

[0068] Evaluation of cleanability The antifouling property of the surface of each sanitary ware was evaluated by the method described below. A SPECTROPHOTOMETER CM-2600d (manufactured by Konica Minolta, Inc.) was used as a color difference meter. The measurement conditions were as follows. Color system: L * a * b * , mask / gross: S / I+E, UV setting: UV 100%, light source: D65, observation field of view: 10 degrees, mode: SCI. For each sanitary ware, the color values L * , a * , b * at the same position were measured three times, and the average value thereof was used. Specifically, (i) The color values L * , a * , b * at a predetermined measurement position on the surface of each sanitary ware (that is, the position where a line will be drawn with Craypas later) were measured. The measured values are defined as L * (1), a * (1), b * (1). (ii) A line with a width of about 1 mm was drawn at the above measurement position with Craypas while applying a load of about 20 to 30 g / cm 2 . (iii) Thereafter, a commercially available toilet cleaning sheet (trade name: Toilet Quickle, manufactured by Kao Corporation) was wiped in a direction perpendicular to the Craypas line at 100 g / cm 2The sheet was slid back and forth 30 times under load to wipe away the crevice lines. Next, a mask was placed over the area where the crevice lines had been wiped, and tap water was poured over the surface of each sanitary ware to remove the surfactant contained in the cleaning sheet. Then, the tap water was removed from the surface with compressed air. (iv) Remove the mask and wipe away the crayon lines. The color value L of the measurement location. * a * , b * The measurement was taken. The measured value was L * (2), a * (2), b * (2) (v) From the following formula, the color difference ΔE at the measurement location before and after drawing the crayon line * ab We calculated the value. The results are shown in Table 4. ΔE * ab = [(ΔL * ) 2 +(Δa * ) 2 +(Δb * ) 2 ] 1 / 2 (In the formula, ΔL * =L * (1)-L * (2), Δa * =a * (1)-a * (2), Δb * =b * (1)-b * (2)

[0069] As shown in Table 4, the color difference on the surface of the sanitary ware in Examples 1-4 was 1 or less, while the color difference on the surface of the sanitary ware in Comparative Example 1 was greater than 1. In other words, the crayon lines (stains) drawn on the surface of the sanitary ware in Examples 1-4 were sufficiently wiped away, confirming that these sanitary wares have good stain resistance. In contrast, the crayon lines on the surface of the sanitary ware in Comparative Example 1 were not sufficiently wiped away, confirming that this sanitary ware does not have good stain resistance.

[0070] [Table 4] [Explanation of Symbols]

[0071] 10: Sanitary ware 1: Base material 2: Surface layer 3: Glaze layer 4: Middle class

Claims

1. Sanitary ware comprising a base material and a surface layer, The aforementioned surface layer includes a polycrystalline material. The polycrystalline material comprises TiO₂, ZrO₂, and Ti₂ZrO₂. The 60° gloss of the surface of the aforementioned surface layer is 60 or higher. The aforementioned polycrystalline material has a size of 50 nm to 100 nm, and is used for sanitary ware.

2. Sanitary ware comprising a base material and a surface layer, The aforementioned surface layer includes a polycrystalline material. The polycrystalline material comprises TiO₂, ZrO₂, and Ti₂ZrO₂. The 60° gloss of the surface of the aforementioned surface layer is 60 or higher. Sanitary ware in which the surface roughness (Sa) of the surface layer is less than 0.

35.

3. Sanitary ware comprising a base material and a surface layer, The aforementioned surface layer includes a polycrystalline material. The aforementioned polycrystalline material is TiO ２ , ZrO ２ and Ti ２ ZrO ６ Includes, The 60° gloss of the surface of the aforementioned surface layer is 60 or higher. The size of the aforementioned polycrystalline material is between 50 nm and 100 nm. Sanitary ware in which the surface roughness (Sa) of the surface layer is less than 0.

35.

4. The sanitary ware according to any one of claims 1 to 3, wherein the thickness of the surface layer is 50 nm or more and 100 nm or less.

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