Sanitary ware

Abstract

To provide a sanitary ware that has a practical antivirus property and can also prevent a stain from being attached thereto and allows the attached stain to be easily removed therefrom.SOLUTION: A sanitary ware comprises a pottery substrate and a glaze layer formed on the surface of the pottery substrate. The glaze layer contains a metal element as an antivirus agent, and the metal element is present in a spinodal phase separation state on at least the surface of the glaze layer. Such a sanitary ware has a practical antivirus property and can also prevent a stain from being attached thereto and allows the attached stain to be easily removed therefrom.SELECTED DRAWING: Figure 3B

Description

[Technical Field]

[0001] The present invention relates to sanitary ware, and more particularly to sanitary ware that combines antiviral properties with stain-resistant and stain-removable properties. [Background technology]

[0002] Sanitary ware has a glaze layer formed on its outermost surface to ensure a hygienic surface and to ensure an attractive appearance. To improve hygiene, a technique has been proposed in which an antibacterial agent is added to the glaze layer. For example, CN111393188A (Patent Document 1) discloses a sanitary ware having a base glaze layer and a top glaze layer containing a nanosilver antibacterial agent.

[0003] There have also been reports of composite oxides being given antiviral properties. WO2020 / 017493A1 (Patent Document 2) suggests that composite oxide ceramics containing rare earth elements and other specific metal elements have both water repellency and antibacterial and antiviral properties. Specifically, it discloses that calcined powder (500°C) of composite oxide ceramics (LMO) containing lanthanum (La) and molybdenum (Mo) exhibits higher activity against bacteriophages Qβ and Φ6 than single oxides (La2O3 particles) (paragraphs 0067, 0069-0071, Figure 8).

[0004] Although Patent Document 2 does not confirm a comparison with a single oxide, it discloses that calcined powders (500°C, 400°C, or 550°C) of composite oxide ceramics containing lanthanum (La) and molybdenum (Mo) and / or tungsten (W) (LMO, LWO, LCMO (LMO in which part of the La is substituted with cerium (Ce)), LMWO (LMO in which part of the Mo is substituted with W)) exhibit activity against bacteriophages Qβ and Φ6 (Figures 11, 14-17, and 20).

[0005] In addition, Cosmetology Research Report Vol. 28, 2020, pp. 43-52 (Non-Patent Document 1), written by the inventor of Patent Document 2, also discloses similar content to Patent Document 2, stating that CeO2 shows almost no activity against bacteriophages Qβ and Φ6, whereas La2O3 shows some activity, and that the anti-Qβ and Φ6 activity of La2O3 is lower than that of LMO (page 47, right column, second paragraph, Figure 7).

[0006] On the other hand, examples of imparting antiviral properties to liquid compositions have been reported, and JP 2020-111546 A (Patent Document 3) proposes an antiviral composition containing a rare earth salt, a zinc salt, and water, specifically disclosing that an aqueous solution containing lanthanum chloride, cerium chloride, neodymium chloride, or ytterbium acetate, and zinc gluconate has a lower viral infectivity (Log(PFU)), i.e., higher antiviral properties, than an aqueous solution lacking either the rare earth salt or the zinc salt. Patent Document 3 discloses processing the antiviral composition into fibers and also suggests processing it into coating agents such as paints, but does not disclose processing it into ceramic materials or glaze materials.

[0007] Some of the above-mentioned documents disclose that a combination of a certain metal element (or metal salt) with another metal element (or another metal salt) has antiviral properties. However, no examples have been reported to date that a metal element alone has antiviral properties sufficient for practical use. Furthermore, none of the above-mentioned documents considers imparting antiviral properties to the glaze layer of sanitary ware. Meanwhile, due to the recent COVID-19 pandemic and other factors, there is an increasing need for sanitary ware with a top glaze layer that has practical antiviral properties. Furthermore, adding additives to the glaze generally roughens the surface of the sanitary ware, which can be undesirable from the standpoint of stain resistance or design. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] CN111393188A publication [Patent Document 2] WO2020 / 017493A1 publication [Patent Document 3] Japanese Patent Publication No. 2020-111546 [Non-patent literature]

[0009] [Non-Patent Document 1] Cosmetology Research Report Vol.28,2020,pp.43-52 Summary of the Invention [Problem to be solved by the invention]

[0010] The present inventors have now confirmed through experiments that when a metal element is present in a specific state in the glaze layer of sanitary ware, the metal element alone exhibits practical antiviral properties and further realizes surface properties that are excellent in terms of stain resistance and ease of removal (properties that make stains difficult to adhere and easy to remove).The present invention is based on these findings.

[0011] Therefore, an object of the present invention is to provide sanitary ware provided with a glaze layer that has practical antiviral properties and that makes stains less likely to adhere and easier to remove. [Means for solving the problem]

[0012] The sanitary ware according to the present invention has the following features: A pottery body and a glaze layer formed on the surface of the pottery body, the glaze layer contains a metal element as an antiviral agent, The metallic element is characterized by being present in a spinodal phase separation state at least on the surface of the glaze layer. [Effects of the Invention]

[0013] According to the present invention, there is provided sanitary ware having a glaze layer that has practical antiviral properties and that makes stains less likely to adhere and easier to remove. [Brief explanation of the drawings]

[0014] [Figure 1A] 1 is a schematic diagram of a sanitary ware according to the present invention. [Figure 1B] FIG. 1 is a schematic diagram of a sanitary ware according to one embodiment of the present invention. [Figure 2] 1 shows an XRD pattern of the glaze layer of the sanitary ware according to the present invention. [Figure 3A] 1 is an SEM image of the surface of the glaze layer of the sanitary ware according to the present invention, showing that lanthanum (La) is present in a spinodal phase separation state on the surface of the glaze layer. [Figure 3B] 1 is a cross-sectional SEM image of the glaze layer of the sanitary ware according to the present invention, showing that lanthanum (La) is present in a spinodal phase separation state near the surface of the glaze layer. [Figure 4A] 1 is an SEM image of the surface of the glaze layer of the sanitary ware according to the present invention, showing neodymium (Nd) present in a spinodal phase separation state on the surface of the glaze layer. [Figure 4B] 1 is a cross-sectional SEM image of the glaze layer of the sanitary ware according to the present invention, showing neodymium (Nd) existing in a spinodal phase separation state near the surface of the glaze layer. [Figure 5A] 1 is an SEM image of the surface of the glaze layer of the sanitary ware according to the present invention, showing that praseodymium (Pr) is present in a spinodal phase separation state on the surface of the glaze layer. [Figure 5B] 1 is a cross-sectional SEM image of the glaze layer of the sanitary ware according to the present invention, showing that praseodymium (Pr) is present in a spinodal phase separation state near the surface of the glaze layer. [Figure 6A] 1 is an SEM image of the surface of the glaze layer of the sanitary ware according to the present invention, showing that samarium (Sm) is present in a spinodal phase separation state on the surface of the glaze layer. [Figure 6B] 1 is a cross-sectional SEM image of the glaze layer of the sanitary ware according to the present invention, showing that samarium (Sm) is present in a spinodal phase separation state near the surface of the glaze layer. [Figure 7A]1 is an SEM image of the surface of the glaze layer of the sanitary ware according to the present invention, showing gadolinium (Gd) present in a spinodal phase separation state on the surface of the glaze layer. [Figure 7B] 1 is a cross-sectional SEM image of the glaze layer of the sanitary ware according to the present invention, showing gadolinium (Gd) present in a spinodal phase separation state near the surface of the glaze layer. [Figure 8A] 1 is an SEM image of the surface of the glaze layer of the sanitary ware according to the present invention, showing that dysprosium (Dy) is present in a spinodal phase separation state on the surface of the glaze layer. [Figure 8B] 1 is a cross-sectional SEM image of the glaze layer of the sanitary ware according to the present invention, showing that dysprosium (Dy) is present in a spinodal phase separation state near the surface of the glaze layer. [Figure 9A] 1 is an SEM image of the surface of the glaze layer of the sanitary ware according to the present invention, showing that holmium (Ho) is present in a spinodal phase separation state on the surface of the glaze layer. [Figure 9B] 1 is a cross-sectional SEM image of the glaze layer of the sanitary ware according to the present invention, showing that holmium (Ho) is present in a spinodal phase separation state near the surface of the glaze layer. [Figure 10A] 1 is an SEM image of the surface of the glaze layer of the sanitary ware according to the present invention, showing that erbium (Er) is present in a spinodal phase separation state on the surface of the glaze layer. [Figure 10B] 1 is a cross-sectional SEM image of the glaze layer of the sanitary ware according to the present invention, showing that erbium (Er) is present in a spinodal phase separation state near the surface of the glaze layer. [Figure 11A] 1 is an SEM image of the surface of the glaze layer of the sanitary ware according to the present invention, showing that ytterbium (Yb) is present in a spinodal phase separation state on the surface of the glaze layer. [Figure 11B] 1 is a cross-sectional SEM image of the glaze layer of the sanitary ware according to the present invention, showing that ytterbium (Yb) is present in a spinodal phase separation state near the surface of the glaze layer. [Figure 12A] 1 is an SEM image of the surface of the glaze layer of the sanitary ware according to the present invention, showing that yttrium (Y) is present in a spinodal phase separation state on the surface of the glaze layer. [Figure 12B] 1 is a cross-sectional TEM image of the glaze layer of the sanitary ware according to the present invention, showing the presence of yttrium (Y) in a spinodal phase separation state near the surface of the glaze layer. [Figure 13A] The relationship between the amount of lanthanum converted to lanthanum oxide and the amount of lanthanum eluted onto the surface of the glaze layer is shown. [Figure 13B] The relationship between the amount of lanthanum eluted and the antiviral activity value is shown. [Figure 14A] The relationship between the amount of lanthanum converted to lanthanum oxide (wt%) and the atomic abundance (mass%) of lanthanum measured by XRF is shown. [Figure 14B] The figure shows the relationship between the atomic abundance (mass%) of lanthanum measured by XRF and the antiviral activity value. [Figure 15A] This is an SEM cross-sectional image showing the state of lanthanum in a glaze layer when a glaze containing 10% by weight of lanthanum oxide as a raw material for an antiviral agent was fired under firing condition 1 (1200°C for a short time). [Figure 15B] This is an SEM cross-sectional image showing the state of lanthanum in a glaze layer when a glaze containing 10% by weight of lanthanum oxide as a raw material for the antiviral agent was fired under firing condition 2 (1200°C for a medium time). [Figure 15C] This is an SEM cross-sectional image showing the state of lanthanum in a glaze layer when a glaze containing 10% by weight of lanthanum oxide as a raw material for an antiviral agent was fired under firing condition 3 (1200°C for a long time). DETAILED DESCRIPTION OF THE INVENTION

[0015] definition In this invention, "sanitary ware" refers to ceramic products used in toilets and around washrooms, specifically toilet bowls, urinals, toilet strainers, toilet tanks, washbasins in bathrooms, hand basins, etc. Furthermore, "pottery" refers to ceramics with a base that is fired to a degree that it is slightly absorbent and has a glazed surface.

[0016] Furthermore, with regard to the present invention, the phrase "a metal element alone" exhibits practical antiviral activity means that the metal element itself exhibits practical antiviral activity, whereas the composite oxide disclosed in Patent Document 2 exhibits antiviral activity by being made of lanthanum and other metal elements (Mo, W), and the liquid composition disclosed in Patent Document 3 exhibits antiviral activity by containing a rare earth salt and other metal salt (zinc salt).

[0017] Sanitary ware As shown in FIG. 1A, the sanitary ware according to the present invention comprises at least a ceramic body 10 and a glaze layer 20 containing an antiviral agent formed on the surface thereof.

[0018] Sanitary ware 1 according to the present invention may further include one or more additional glaze layers between the ceramic body 10 and the glaze layer 20 containing the antiviral agent. For example, according to one embodiment of the present invention, as shown in FIG. 1B , sanitary ware 1 includes a ceramic body 10, a glaze layer 30 formed on the surface of the ceramic body 10, and a glaze layer 20 containing an antiviral agent formed on the surface of the glaze layer 30. In the present invention, glaze layer 30 is sometimes referred to as a base glaze layer, and glaze layer 20 is sometimes referred to as an antiviral glaze layer. The base glaze layer 30 is not particularly limited and may be a glaze layer that is typically applied to a ceramic body. In the present invention, the "surface" of the glaze layer 20 refers to a surface at a depth of 0 μm in the depth direction indicated by the arrow in Fig. 1A or 1B. Furthermore, the "near-surface" of the glaze layer 20 refers to a region extending from the surface of the glaze layer 20 to a depth of, for example, about 1 / 10 or 1 / 15 of the thickness of the glaze layer 20 in the depth direction indicated by the arrow in Fig. 1A or 1B.

[0019] Ceramic base The ceramic body 10 is not particularly limited and may be a conventionally known ceramic body, i.e., a sanitary ware body slurry prepared from silica sand, feldspar, clay, or the like, which is appropriately molded.

[0020] Glaze layer In the present invention, the glaze layer 20 contains, as its components, a metal element as an antiviral agent and a glaze material described below. The metal element as the antiviral agent is present in a spinodal phase separation state at least on the surface of the glaze layer 20.

[0021] Presence state of antiviral agent in glaze layer 20 In the present invention, the antiviral agent is present in an amorphous (non-crystalline) state at least on the surface of the glaze layer 20. Specifically, the antiviral agent is present in a vitrified state at least on the surface of the glaze layer 20. More specifically, the antiviral agent is present in a spinodal phase separation state in the glaze layer 20. In the present invention, "spinodal phase separation" generally refers to a state in which particle precipitation due to crystallization is suppressed in the glaze layer, resulting in the effect that the antiviral agent is more likely to leach out stably onto the surface of the glaze layer and that the presence of the antiviral agent on the surface of the glaze layer has less of an effect on the surface properties of the glaze layer. The presence of the antiviral agent in a spinodal phase separation state on at least the surface of the glaze layer 20 allows the antiviral agent to be chemically stable, ionized, and eluted from the surface of the glaze layer 20, thereby making it possible to efficiently inactivate viruses attached to the surface of the glaze layer 20. In this way, the glaze layer 20 can exhibit good antiviral properties. In addition, the presence of the antiviral agent in a spinodal phase separation state on at least the surface of the glaze layer 20 allows an antiviral-agent-rich phase to be uniformly present on the surface, allowing the antiviral agent to be eluted stably, resulting in high antiviral properties.

[0022] In the present invention, the antiviral agent is preferably present in a spinodal phase separation state in a region extending from the surface of the glaze layer 20 to a depth of 10 nm in the depth direction indicated by the arrow in Fig. 1A or 1B. The presence of the antiviral agent in a spinodal phase separation state in such a region promotes elution of the antiviral agent, enabling the glaze layer 20 to exhibit better antiviral properties. In addition, the effect on the surface properties of the glaze layer surface can be further reduced.

[0023] The presence of the antiviral agent in a spinodal phase separation state on at least the surface of the glaze layer 20 is achieved by integrally firing the ceramic body 10 and the glaze that forms the glaze layer 20 once, followed by cooling, as described below. Specifically, by integrally firing the ceramic body 10 and the glaze that forms the glaze layer 20 once and then cooling, it is possible to induce a glass phase separation phenomenon. Glass phase separation is a phenomenon in which single-phase glass separates into multiple phases. When glass consisting of multiple components exists as a homogeneous liquid phase (molten glass), as the temperature decreases, there exists a region where the free energy is lower in a two-phase mixture state than in a single-phase state. The molten glass in such a region undergoes phase separation because the two-phase separation is thermodynamically more stable.

[0024] In the present invention, a glaze composed of multiple components, such as a metal compound that is the starting material for the antiviral agent (metal element) contained in glaze layer 20, and metal oxides other than SiO2 and the antiviral agent raw material compounds described below, is fired to form a uniform (single) glass liquid phase (glass melt). This glass melt is placed in a metastable immiscible region by cooling to a temperature below the liquidus line in the glass phase equilibrium diagram. The metastable immiscible region includes (i) a binodal region in which the glass melt undergoes phase separation through a nucleation-growth mechanism in which nuclei are generated and grow, and (ii) a spinodal region in which the glass melt becomes thermodynamically unstable and undergoes phase separation without nucleation (spinodal decomposition mechanism). In the binodal region, one of the two phases formed by phase separation exists as a dispersed spherical particle that is not entangled with the other. In the spinodal region, one of the two phases formed by phase separation exists as a dispersed nonspherical particle that is highly entangled with the other. Theoretically, it is believed that the antiviral agent can be in both a spinodal phase-separated state and a binodal phase-separated state in the glaze layer. In the present invention, by integrally firing the ceramic body 10 and the glaze for forming the glaze layer 20 once and cooling them, the antiviral agent can be made to exist in a rich state near the surface of the glaze layer, and the proportion of the antiviral agent present near the surface of the glaze layer in a spinodal phase-separated state can be made higher than the proportion of the antiviral agent present in a binodal phase-separated state, although the details of the mechanism are not clear. This has been confirmed by experiments, as will be described later. For example, as shown in Figures 3 to 12, the antiviral agent is present in a rich state near the surface of the glaze layer 20, and this antiviral agent is present in a spinodal phase-separated state.

[0025] Note that embodiments in which a specific lanthanoid is present in a spinodal phase separation state near the surface of the glaze layer are considered to include states in which an antiviral agent-rich phase is present entangled with a phase not rich in antiviral agent (-Si-O- structure), or a state in which an antiviral agent-rich portion is more entangled with a portion not rich in antiviral agent (i.e., present uniformly with higher resolution), whereby an antiviral agent-rich portion cooperates with other portions in the glass matrix structure on the surface of the glaze layer to form an entangled structure as a whole. The presence of the antiviral agent near the surface of the glaze layer in such a state enables or promotes the antiviral agent to be eluted uniformly from the surface of the glaze layer from a macroscopic perspective, and as a result, high antiviral properties are considered to be exhibited.

[0026] It is sufficient that a region where the antiviral agent has undergone spinodal phase separation is present on the surface of the glaze layer 20 within a range where the effects of the present invention are achieved, and the present invention does not exclude an embodiment where the region where the antiviral agent has undergone binodal phase separation is present at a lower rate than the region where the antiviral agent has undergone spinodal phase separation due to, for example, unavoidable circumstances in the process of producing the glaze layer 20, within a range where the effects of the present invention are not impaired.

[0027] Confirmation of the state of existence of the antiviral agent in the glaze layer 20 XRD measurement The presence of the antiviral agent in an amorphous (non-crystalline) state, specifically in a vitrified state, at least on the surface of the glaze layer 20 can be confirmed by XRD measurement of the surface of the glaze layer 20. For example, an XRD device manufactured by PANalytical<X’Pert PRO> Measurement is carried out using the following conditions, and if no peak is observed, it is confirmed that the material is not crystalline, that is, is in an amorphous (non-crystalline) state, preferably in a vitrified state. XRD measurement conditions Measurement range: 3°~60° Scan rate: 4° / min Applied voltage: 45V, applied current: 40mA

[0028] SEM measurement, TEM measurement The presence of the antiviral agent in a spinodal phase separation state at least on the surface of the glaze layer 20 can be confirmed by SEM or TEM observation of a region including the surface of the glaze layer 20. For example, SEM observation can be performed using an S4800 (Hitachi High-Technologies Corporation) under conditions of 50,000x magnification, 2.0 kV applied voltage, and 20 mA applied current (2.0 mm x 50.0 k SE (U, LA100)). TEM observation can be performed using an H-9500 (Hitachi High-Technologies Corporation) under conditions of 100,000x magnification and 200 kV applied voltage.

[0029] antiviral agents In the present invention, the antiviral agent is preferably a rare earth element, namely the lanthanides as well as scandium (Sc) and yttrium (Y). The lanthanoid is preferably at least one lanthanoid selected from the group consisting of 12 elements: lanthanum (La), praseodymium (Pr), neodymium (Nd), samarium (Sm), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu). In other words, the antiviral agent is preferably a lanthanoid excluding cerium (Ce), europium (Eu), and promethium (Pm) (hereinafter, the above 12 lanthanoids excluding Ce, Eu, and Pm may be referred to as "specific lanthanoids"). According to a preferred embodiment of the present invention, the specific lanthanoid is at least one selected from the group consisting of La, Gd, Dy, and Yb.

[0030] The reason why Ce and Eu are excluded from the lanthanides is that these two atoms are the only lanthanides that stably have two valencies. That is, Ce atoms stably have two valencies, +3 and +4, while Eu atoms stably have two valencies, +2 and +3. Therefore, by donating electrons to the Si-O bonds of the glaze layer 20, they affect the Si-O bonds by elongating them, thereby affecting the vitrified structure of the glaze layer 20 and resulting in a rough surface. This makes it impossible to achieve the surface properties described below, making them unsuitable as components to be included in the glaze layer 20. In other words, when imparting antiviral properties to the glaze layer of sanitary ware, it is preferable to use an antiviral agent that has minimal effect on the Si-O bonds. In the present invention, the reason why Pm is excluded from the lanthanoids is that, among the lanthanoids, this atom does not exist stably, is radioactive, and has physical properties that are significantly different from those of other lanthanoids.

[0031] In the present invention, the antiviral property of the sanitary ware having the glaze layer 20 containing a metal element present in a spinodal phase state on at least the surface thereof can be expressed as an index of antiviral activity against bacteriophage Qβ. The antiviral activity value can be determined, for example, by the following test method in accordance with ISO 21702.

[0032] <Antiviral test method> 0.4 mL of the virus solution is dropped onto the test pieces (a sanitary ware test piece with a glaze layer containing the antiviral agent, and a control (a sanitary ware test piece with a glaze layer not containing the antiviral agent)), and then covered with a film. - Leave the test piece at 25°C for 24 hours. After leaving it to stand, the virus on the test piece is washed and collected, and then the virus infectivity is measured. Calculate the antiviral activity value using the following formula to evaluate the antiviral properties. R=Ut-At R: Antiviral activity value Ut: Viral infectivity of the control after 24 hours (PFU / cm 2 ) At: Virus infectivity (PFU / cm) of a test piece of sanitary ware with a glaze layer containing an antiviral agent after leaving it for 24 hours 2 )

[0033] In the present invention, the antiviral activity of sanitary ware equipped with a glaze layer containing an antiviral agent can be expressed as an index using the antiviral activity value (V) determined according to JIS R1756 visible light B conditions in a bright place. Specifically, an antiviral test was conducted using bacteriophage Qβ in accordance with JIS R1756 visible light B conditions. A 20W white fluorescent lamp (Toshiba Lighting & Technology Corporation, "Neoline" FL20S·W) was used as the light source, and visible light of 380 nm or more was irradiated at an illuminance of 500 lux through a UV-cut filter (Nitto Jushi Kogyo Co., Ltd., N-169). The illuminance was measured using an IM-5 illuminometer manufactured by Topcon Corporation. The antiviral activity value (V) in a bright place was calculated using the following formula, assuming a visible light irradiation time of 4 hours.

[0034] Antiviral activity value: V=Log 10 (UV / TV) TV: Bacteriophage infectivity titer (pfu) of sanitary ware with a glaze layer containing an antiviral agent after light irradiation UV: Bacteriophage infectivity titer (pfu) per control after light irradiation As a control, sanitary ware with a glaze layer that does not contain the antiviral agent will be used.

[0035] In the present invention, the glaze layer 20 containing the antiviral agent preferably has an antiviral activity value of 2 to 6. An antiviral activity value of 2 or more satisfies the practical antiviral performance standard for sanitary ware.

[0036] In the present invention, the amount of rare earth element eluted on the surface of the glaze layer 20 to exhibit practical virus activity is preferably at least as shown below. Scandium (Sc): approx. 0.02 ppm Yttrium (Y): approx. 0.03 ppm Lanthanum (La): approx. 0.05 ppm Praseodymium (Pr): approx. 0.052 ppm Neodymium (Nd): approx. 0.052 ppm Samarium (Sm): approx. 0.054 ppm Gadolinium (Gd): approx. 0.056 ppm Terbium (Tb): approx. 0.057 ppm Dysprosium (Dy): Approximately 0.057 ppm Holmium (Ho): approx. 0.058 ppm Erbium (Er): approx. 0.059 ppm Thulium (Tm): approx. 0.059 ppm Ytterbium (Yb): Approximately 0.060 ppm Lutetium (Lu): approx. 0.061 ppm In addition, in a preferred embodiment of the present invention, the amount of eluted rare earth elements is approximately 1 to 2% of the content of rare earth elements contained in a region 10 nm deep from the surface of the glaze layer toward the pottery body (the direction of the arrow shown in Figure 1).

[0037] In a preferred embodiment of the present invention, the content of the antiviral agent contained in the glaze layer 20 is preferably 1.0% by weight or more and 25% by weight or less, more preferably 5% by weight or more and 12% by weight or less, and even more preferably 5% by weight or more and 9% by weight or less, calculated as the oxide of the antiviral agent, when the total of the antiviral agent constituting the glaze layer and other glaze materials described below is taken as 100% by weight. Needless to say, the amount of the oxide of the antiviral agent can be stoichiometrically converted to the weight % of the antiviral agent.

[0038] The preferred contents (in terms of oxides) of the antiviral agent preferably contained in the glaze layer 20 for each rare earth element are as follows: Scandium (Sc): 0.4 wt% to 8.0 wt%, the upper limit is preferably about 5.6 wt%, more preferably 4.4 to 4.8 wt%, and even more preferably about 3.6 wt%, and the lower limit is preferably 2 wt% or more. Yttrium (Y): 0.7% to 14.0% by weight, the upper limit is preferably about 9.8% by weight, more preferably 7.7 to 8.4% by weight, and even more preferably about 6.3% by weight, and the lower limit is preferably 3.5% by weight or more. Lanthanum (La): 1.0 wt% to 20.0 wt%, with the upper limit preferably being about 14 wt%, more preferably 11 to 12 wt%, and even more preferably about 9 wt%, and the lower limit preferably being 5 wt% or more. Praseodymium (Pr): 1.0 wt% to 20.0 wt%, the upper limit is preferably about 14 wt%, more preferably 11 to 12 wt%, and even more preferably about 9 wt%, and the lower limit is preferably 5 wt% or more. Neodymium (Nd): 1.0 wt % to 20.0 wt %, the upper limit is preferably about 14 wt %, more preferably 11 to 12 wt %, and even more preferably about 9 wt %, and the lower limit is preferably 5 wt % or more. Samarium (Sm): 1.1 wt% to 22.0 wt%, the upper limit is preferably about 15.4 wt%, more preferably 12.1 to 13.2 wt%, and even more preferably about 9.9 wt%, and the lower limit is preferably 5.5 wt% or more. Gadolinium (Gd): 1.1 wt% to 22.0 wt%, the upper limit is preferably about 15.4 wt%, more preferably 12.1 to 13.2 wt%, and even more preferably about 9.9 wt%, and the lower limit is preferably 5.5 wt% or more. Terbium (Tb): 1.1 wt% to 22.0 wt%, the upper limit is preferably about 15.4 wt%, more preferably 12.1 to 13.2 wt%, and even more preferably about 9.9 wt%, and the lower limit is preferably 5.5 wt% or more. Dysprosium (Dy): 1.1 wt% to 22.0 wt%, the upper limit is preferably about 15.4 wt%, more preferably 12.1 to 13.2 wt%, and even more preferably about 9.9 wt%, and the lower limit is preferably 5.5 wt% or more. Holmium (Ho): 1.2 wt% to 24.0 wt%, the upper limit is preferably about 16.8 wt%, more preferably 13.2 to 14.4 wt%, and even more preferably about 10.8 wt%, and the lower limit is preferably 6 wt% or more. Erbium (Er): 1.2 wt% to 24.0 wt%, the upper limit is preferably about 16.8 wt%, more preferably 13.2 to 14.4 wt%, and even more preferably about 10.8 wt%, and the lower limit is preferably 6 wt% or more. Thulium (Tm): 1.2 wt% to 24.0 wt%, the upper limit is preferably about 16.8 wt%, more preferably 13.2 to 14.4 wt%, and even more preferably about 10.8 wt%, and the lower limit is preferably 6 wt% or more. Ytterbium (Yb): 1.2 to 24.0% by weight, with the upper limit preferably being approximately 16.8% by weight, more preferably 13.2 to 14.4% by weight, and even more preferably approximately 10.8% by weight, and the lower limit preferably being 6% by weight or more. Lutetium (Lu): 1.2 wt% to 24.0 wt%, the upper limit is preferably about 16.8 wt%, more preferably 13.2 to 14.4 wt%, and even more preferably about 10.8 wt%, and the lower limit is preferably 6 wt% or more.

[0039] The glaze layer 20 can exhibit better antiviral properties by containing rare earth elements in the amounts within the above-mentioned ranges.

[0040] In the present invention, the content of the antiviral agent contained in the glaze layer 20 can also be quantified by analyzing the glaze layer 20 by X-ray fluorescence spectrometry (XRF). In the present invention, the atomic abundance (mass%) of the antiviral agent contained in the glaze layer 20 can be determined using a scanning X-ray fluorescence analyzer (Rigaku ZSX PrimusIV (manufactured by Rigaku Corporation)) under the following measurement and analysis conditions. (Measurement conditions) Tube voltage: 60kV Tube current: 50mA Measurement depth: Several tens of μm (approximately 0 to 50 μm) Measurement area: Φ20mm (Analysis conditions) La detection line: La Lα (alpha) line, 2θ=82.88 Spectroscopic crystal: LiF(200) Detector: SC The scanning X-ray fluorescence analyzer has a measurement limit of a region from the outermost surface (0 μm) of the glaze layer 20 to a depth of approximately 50 μm in the direction of the ceramic body (the direction of the arrow in FIG. 1 ). Therefore, in the present invention, the quantification of the antiviral agent using the scanning X-ray fluorescence analyzer identifies the glaze layer 20 based on the content (mass%) of the antiviral agent in a region from the outermost surface of the glaze layer 20 to a depth of approximately 50 μm.

[0041] The atomic abundance of the antiviral agent measured by X-ray fluorescence spectroscopy (XRF) has the advantage that it is possible to accurately measure the content of the antiviral agent contained in a region from the outermost surface (0 μm) of the glaze layer 20 to a depth of approximately 50 μm toward the ceramic body, i.e., in the vicinity of the surface of the glaze layer 20. That is, the content of the antiviral agent in terms of antiviral agent oxide, as already explained, represents the content ratio (percentage) of the antiviral agent in the entire glaze layer 20, and the content of the antiviral agent measured by X-ray fluorescence analysis (XRF) pinpoints and accurately represents the content ratio of the antiviral agent in the vicinity of the surface of the glaze layer 20. Furthermore, the content of specific lanthanoids measured by X-ray fluorescence spectrometry (XRF) is useful for accurately determining the amounts of various compounds, such as oxides and chlorides of specific lanthanoids, to be added as starting materials for antiviral agents based on stoichiometry.

[0042] In the present invention, the antiviral agent preferably has a melting point higher than a temperature of 800° C. to 1300° C. When the antiviral agent has such a melting point, the antiviral agent is likely to exist in a spinodal phase separation state at least on the surface of the glaze layer 20.

[0043] Other glaze materials Glaze layer 20 contains materials typically used in glazes, such as SiO2, Al2O3, divalent metal oxides, and monovalent metal oxides, along with an antiviral agent. According to a preferred embodiment of the present invention, the weight percentage of SiO2 relative to the glass component is 52 to 76%, the weight percentage of Al2O3 relative to the glass component is 6 to 14%, the weight percentage of divalent metal oxide relative to the glass component is 11.4 to 27.6%, and the weight percentage of monovalent metal oxide relative to the glass component is 1.5 to 6.5%.

[0044] The glaze layer 20 is primarily composed of SiO2, Al2O3, divalent metal oxides, and monovalent metal oxides, but may also contain Fe2O3, TiO2, V2O5, etc. Divalent metal oxides that can be used include alkaline earth metal oxides such as CaO and MgO, ZnO, and CuO. Monovalent metal oxides that can be used include Na2O, K2O, and Li2O.

[0045] In the present invention, preferred compositions of glaze materials other than the antiviral agent are, for example, as shown in Table 1 below.

[0046] [Table 1]

[0047] surface texture In the glaze layer 20 of the sanitary ware 1 according to the present invention, the antiviral agent is present in a spinodal phase separation state at least on the surface of the glaze layer 20, and therefore, the glaze layer 20 exhibits the antiviral properties described above and has little effect on the surface properties of the glaze layer, thereby achieving the surface properties suitable for sanitary ware described below.

[0048] Average roughness (Ra) In the present invention, the glaze layer 20 preferably has a surface roughness (Ra) of less than 0.07 μm. A surface roughness (Ra) of less than 0.07 μm makes it difficult for urinary stones, mold, yellowing, and other stains to adhere to the sanitary ware, and even if they do adhere, they can be easily removed with a weak water flow. As a result, the surface of the sanitary ware can be kept clean for a long period of time without the need for frequent cleaning operations.

[0049] According to a preferred embodiment of the present invention, Ra is 0.068 μm or less, more preferably 0.05 μm or less, and even more preferably 0.04 μm or less, which further improves the resistance to adhesion of dirt and the ease of removal.

[0050] In the present invention, the "surface roughness (Ra)" refers to the center line average roughness (μm) measured by a stylus surface roughness measuring device (JIS-B0651) and defined by JIS-B0601 (1994).

[0051] DOI value In the present invention, the glaze layer 20 preferably has a DOI value of 80 or more on its surface as measured by a Wave-Scan DOI measuring device. In the present invention, the "DOI value" refers to a DOI value measured using a Wave-Scan DOI measuring device, such as the Wave-ScanDIO (orange peel measuring device) manufactured by BYK Gardner GmbH (Germany). In the present invention, the DOI value is used as an index representing the image clarity of the surface of the glaze layer provided on the sanitary ware according to the present invention. "Image clarity" refers to the clarity of the reflection of objects, and this appearance quality is determined by the difference in light reflection depending on the surface shape of the glaze layer, and is perceived by the human visual sense.

[0052] A DOI value of 80 or higher on the surface of the glaze layer 20 gives the viewer an impression of excellent image clarity, resulting in a luxurious feel for the sanitary ware. Furthermore, good image clarity makes stains on the sanitary ware more noticeable, allowing early detection of virus-containing contaminants, thereby preventing contaminants from being left unattended. In the present invention, the antiviral agent is present on the surface of the glaze layer 20 in a spinodal phase separation state, which causes scattering at the interface between the two phases, resulting in a white glaze layer surface with excellent image clarity. According to a preferred embodiment of the present invention, the DOI value of the surface of the glaze layer 20 is 85 or higher.

[0053] The Wavescan DOI measurement device moves a laser point source across the surface of a glaze layer, scanning it, measuring the brightness / darkness of the reflected light point by point at set intervals, just like the human eye, to detect the optical profile of the glaze layer's surface. This optical profile is then passed through a frequency filter for spectral analysis, allowing the structure of the glaze layer's surface to be analyzed. Microwave scanning using the device involves irradiating the glaze layer surface with laser light from a laser point source at an angle of 60° from the perpendicular, and a detector measuring the reflected light at the same angle but opposite to the perpendicular. The characteristic spectrum of the device is as follows: du: Wavelength 0.1mm or less Wa: Wavelength 0.1~0.3mm Wb: Wavelength 0.3~1mm Wc: Wavelength 1~3mm Wd: Wavelength 3~10mm We: Wavelength 10~30mm Sw: Wavelength 0.3~1.2mm Lw: Wavelength 1.2~12mm DOI: Wavelength 0.3mm or less Here, DOI is a parameter consisting of du, Wa, and Wb, and is expressed as DOI=f(du,Wa,Wb).

[0054] Color difference: ΔE* value In the present invention, the glaze layer 20 preferably has a color difference (ΔE* value) of 1.20 or less on its surface. Having a ΔE* value of 1.20 or less on the surface of the glaze layer 20 allows for the production of sanitary ware with excellent light resistance. The ΔE* value is measured by conducting a weathering test using a sunshine carbon arc lamp weathering tester (S-300, manufactured by Suga Test Instruments Co., Ltd.) in accordance with the sunshine carbon arc lamp method described in Chapter 9, Section 8 of JIS K5400 (1990). The test lasts for 8 hours, and the L*, a*, and b* values ​​of the photocatalyst-coated body before and after the test are measured using the SCE method, resulting in a color difference: ΔE*=[(ΔL*) 2 +(Δa*) 2 +(Δb*) 2 ] 1 / 2 A color difference meter (Konica Minolta, CR-400) can be used as the color difference meter. The color difference: ΔE* value of the surface of the glaze layer 20 is more preferably 0.8 or less, and even more preferably 0.7 or less.

[0055] Film Thickness In the present invention, the film thickness of the glaze layer 20 is preferably 50 to 1200 μm, more preferably 100 to 800 μm, and even more preferably 150 to 400 μm. The glaze layer 20 having such a thickness can achieve the above-mentioned surface texture.

[0056] Manufacturing method The sanitary ware according to the present invention can be preferably produced by the following method.

[0057] First, a ceramic body 10 is prepared. The ceramic body 10 may be a conventionally known sanitary ware body slip prepared from silica sand, pottery stone, clay, or the like, which is appropriately molded.

[0058] A glaze slurry for forming the glaze layer 20, that is, a glaze slurry containing an antiviral agent compound as a starting material for the antiviral agent and other glaze materials, is prepared. The composition of the glaze materials other than the antiviral agent is, for example, as shown in Table 1 above. Furthermore, as the antiviral compound, for example, an oxide of the antiviral agent can be used, which has a boiling point of 1000°C or higher, more preferably a boiling point of 1300°C or higher and a melting point of 1000°C or higher. Even more preferably, the compound has a melting point of 1000°C or higher and is water-insoluble.

[0059] The glaze slurry for forming the glaze layer 20 can be prepared, for example, as follows. Embodiment 1 A glaze material having the composition shown in Table 1, water, and a dispersion medium (e.g., alumina balls) are placed in a ceramic pot and pulverized, for example, using a ball mill to obtain a glaze slurry precursor. An antiviral compound is added to this glaze slurry precursor, and the mixture is mixed and pulverized to obtain a glaze slurry for forming the glaze layer 20. Embodiment 2 A glaze material having the composition shown in Table 1 is melted at a predetermined temperature and cooled to obtain a frit raw material. An antiviral compound is added to this frit raw material, and water, a dispersion medium, and other raw materials (e.g., pottery stone, ZnO, etc.) are further added as needed. The mixture is placed in a ceramic pot and pulverized, for example, by a ball mill to obtain a glaze slurry for forming the glaze layer 20. In a preferred aspect of this embodiment, the content of the antiviral compound in the glaze slurry is the weight percentage of the antiviral compound when the total of the frit raw material and the other raw materials is taken as 100% by weight.

[0060] According to a preferred aspect of the present invention, in the above-mentioned first and second embodiments, it is preferable that the average particle size of the antiviral compound after pulverization is approximately the same as the average particle size of the glaze material after pulverization. For example, it is preferable that the average particle sizes of the antiviral compound and the glaze material are approximately the same, 10 μm or less, preferably about 6 to 7 μm. Here, the average particle size refers to the so-called 50% particle size in particle size distribution data measured by laser diffraction. Furthermore, "approximately the same" average particle size means that the ratio (former / latter) of the average particle size of the antiviral compound to the average particle size of the glaze material is within the range of 0.9 to 1.1.

[0061] By adjusting the average particle sizes of the antiviral agent compound and the glaze material in this way, it is possible to cause the antiviral agent to exist in a spinodal phase separation state on at least the surface of the glaze layer 20, and to achieve the above-described surface properties (Ra, DOI value, ΔE* value).

[0062] Next, the glaze slurry for forming the glaze layer 20 is applied to the surface of the ceramic body 10. There are no particular limitations on the application method, and general methods such as spray coating and dip coating can be appropriately selected and used.

[0063] Next, the ceramic body 10 to which the glaze slurry for forming the glaze layer 20 has been applied is fired. That is, the ceramic body 10 and the glaze slurry are fired together. The firing temperature is preferably a temperature at which the sanitary ware body sinters and the glaze softens, and is also lower than the melting point of the antiviral agent. Such a firing temperature is preferably 1000°C or higher and 1300°C or lower, more preferably 1150°C or higher and 1250°C or lower. The firing together is preferably performed only once. The inventors have experimentally confirmed that performing the firing together only once suppresses crystallization of the antiviral agent. Specifically, they have confirmed that multiple firings cause crystals to precipitate from the amorphous layer of the glaze layer, and that, for example, a second firing at a temperature lower than the first firing temperature causes crystals to precipitate.

[0064] The resulting fired body is then cooled. The cooling conditions are not particularly limited, and the body may be cooled naturally or by appropriately controlling the temperature and time.

[0065] Ceramic base 10 and a glaze slurry prepared so that the average particle size of the antiviral agent compound and the average particle size of the other glaze materials are approximately the same are fired together once at a temperature lower than the melting point of the antiviral agent, and then cooled to preferably vitrify the antiviral agent while suppressing crystallization of the antiviral agent, more preferably to form a glass liquid phase (glass melt), even more preferably to cause phase separation of the glass melt, and most preferably to cause spinodal phase separation, resulting in a glaze layer 20 in which regions where the antiviral agent has undergone spinodal phase separation are abundant on the surface. [Example]

[0066] The present invention will be specifically described based on the following examples, but the present invention is not limited to these examples.

[0067] Making pottery base A 70mm x 150mm plate-shaped test piece was prepared using ceramic slurry prepared from silica sand, feldspar, clay, etc.

[0068] Preparation of glaze slurry for forming base glaze layer 2 kg of glaze material having the composition shown in Table 2 below, 1 kg of water, and 4 kg of alumina balls were placed in a 6 L ceramic pot, and the mixture was pulverized in a ball mill so that the particle size of the glaze slurry after pulverization measured using a laser diffraction particle size distribution analyzer was 65% below 10 μm and 50% had a particle size of approximately 6.5 μm, thereby obtaining a glaze slurry for forming a base glaze layer.

[0069] [Table 2]

[0070] Preparation of glaze slurry for forming antiviral glaze layer 2 kg of glaze material having the composition shown in Table 3 below, 1 kg of water, and 4 kg of alumina balls were placed in a 6-L ceramic pot and pulverized in a ball mill so that the particle size of the glaze slurry after pulverization measured using a laser diffraction particle size analyzer would be 65% 10 μm or less and the 50% particle size (D50) would be 6.5 μm. This glaze slurry precursor was obtained. 5 wt% of the metal element oxides shown in Table 4 were added to this glaze slurry precursor (i.e., 5 wt% of the metal element oxides were added relative to 100 wt% of the total content of the glaze materials), mixed, and pulverized in a ball mill so that 65% of the particles would be 10 μm or less and the 50% particle size (D50) would be 6.5 μm. The antiviral glaze slurries for sanitary ware of Examples 1 to 10 and Comparative Example 1 were prepared.

[0071] [Table 3]

[0072] Sanitary ware manufacturing Each antiviral glaze slurry prepared as described above was spray-coated onto the ceramic body test pieces, which were then fired once in a kiln at 1200°C and cooled to produce the sanitary ware of Examples 1 to 10 and Comparative Example 1.

[0073] evaluation The sanitary wares of Examples 1 to 10 and Comparative Example 1 were evaluated as follows.

[0074] Antiviral content The rare earth element content, calculated as the amount of rare earth element oxide, contained in the glaze layers of the sanitary ware of Examples 1 to 10 and Comparative Example 1 is, for example, calculated as 5 wt% / (100 wt% + 5 wt%) × 100 ≒ 4.8%, where lanthanum oxide (5 wt%) is the percentage of lanthanum oxide relative to the total (105 wt%) of 100 wt% of the glaze material and 5 wt% of lanthanum oxide shown in Table 3. The same applies to the other Examples 2 to 10 and Comparative Example 1.

[0075] antiviral The antiviral activity value against bacteriophage Qβ was determined by the following test method in accordance with ISO 21702. 0.4 mL of the virus liquid was dropped onto the sanitary ware of Examples 1 to 10 and Comparative Example 1, and onto a control sanitary ware whose glaze layer did not contain an antiviral agent, and then covered with a film. Each piece of sanitary ware was left standing at 25°C for 24 hours. After leaving the sanitary ware to stand, the viruses on each piece of sanitary ware were washed and collected, and the virus infectivity was measured. The antiviral activity value was calculated using the following formula: R=Ut-At R: Antiviral activity value Ut: Virus infectivity (PFU / cm) after 24 hours of standing on the control sanitary ware 2 ) At: Logarithm of virus infectivity titer (PFU / cm 2 ) after 24-hour static placement of the sanitary ceramics of Examples 1 to 10 and Comparative Example 1 The antiviral activity values of the sanitary ceramics of Examples 1 to 10 and Comparative Example 1 were as shown in Table 4. Average roughness (Ra) Using a stylus-type surface roughness measuring device (JIS-B0651), the center line average roughness (μm) defined by JIS-B0601 (1994) was determined. The results were as shown in Table 4.

[0076] DOI value Using a Wave Scan DOI measuring device: Wave-ScanDIO (orange peel measuring device) manufactured by BYK Gardner (Germany), the DOI value was measured. The results were as shown in Table 4.

[0077] Confirmation of the presence of antiviral agents near the surface of the glaze layer <XRD Measurement> Using an XRD device: <X’Pert PRO> manufactured by PANalytical, the measurement was carried out under the following conditions. XRD Measurement Conditions Measurement range: 3° to 60° Scan rate: 4° / min Applied voltage: 45V, applied current: 40mA As shown in Figure 2, no peaks were observed in the XRD measurement of the surface of the antiviral glaze layer containing each metal element. Therefore, it was confirmed that each metal element existed in an amorphous (non-crystalline) state or a vitrified state on the surface of the antiviral glaze layer.

[0078] <SEM Observation, TEM Observation> The presence of each metal element near the surface of the antiviral glaze layer was observed by SEM and TEM. SEM observation was performed using an S4800 (Hitachi High-Technologies) under conditions of 50,000x magnification, 2.0 kV applied voltage, and 20 mA applied current (2.0 mm x 50.0 k SE (U, LA100)). TEM observation was performed using an H-9500 (Hitachi High-Technologies) under conditions of 100,000x magnification and 200 kV applied voltage (MST-20-113310 ID No. 4448c). SEM and TEM images are shown in Figures 3A-12A and 3B-12B. In the SEM images, white areas indicate the presence of each metal element, and black areas indicate the Si-O structure. In the TEM image (Figure 12B), black areas indicate the presence of each metal element, and white areas indicate the Si-O structure. In the cross-sectional SEM image, the white areas that look like boundary lines indicate the presence of each metal element in abundance. In the TEM image (FIG. 12B), the black areas that look like boundary lines indicate the presence of yttrium in abundance. In the cross-sectional SEM image and cross-sectional TEM image, the image region above the boundary line is an air region and is therefore not subject to observation. The images shown in Figures 3 to 12 confirm that each metal element is present in abundance near the surface and on the surface of the antiviral glaze layer, that each metal element has undergone spinodal phase separation, and that the amount of spinodal phase separation of each metal element is abundant.

[0079] [Table 4]

[0080] Furthermore, the results shown in Table 4 confirm that the sanitary ware of Comparative Example 1, which contained Ce, had a low antiviral activity value and poor surface properties (Ra value and DOI value), whereas the sanitary ware of Examples 1 to 10, which contained specific rare earth elements, had a high antiviral activity value and good surface properties (Ra value and DOI value).In other words, it was confirmed that the sanitary ware of the present invention possesses both practical antiviral properties and excellent stain-resistant and stain-easy removal properties, and that these properties are exhibited synergistically.

[0081] Confirmation of the presence (distribution) of antiviral agents in the glaze layer based on their content Sanitary ware of Examples 1 to 15 were produced in the same manner as in Example 1, except that the lanthanum content in the sanitary ware of Example 1 was varied. The amounts (wt %) of lanthanum contained in the glaze layers of the sanitary ware of Examples 1 to 15 converted to lanthanum oxide (La2O3) and the atomic abundances (mass %) measured by XRF were as shown in Table 5. The lanthanum content (wt%) of each sanitary ware shown in Table 5, calculated based on the lanthanum oxide (La2O3) equivalent, was calculated as 5 wt% / (100 wt% + 5 wt%) × 100 ≒ 4.8% for the sanitary ware of Example 4, for example, as the percentage of lanthanum oxide (5 wt%) to the total (105 wt%) of 100 wt% of the glaze material and 5 wt% of lanthanum oxide shown in Table 3. The same applies to Examples 1 to 3 and 4 to 15. The sanitary ware of Example 4 is the same as the sanitary ware of Example 1. Comparing the lanthanum content (wt%) based on the lanthanum oxide (La2O3) equivalent amount for each piece of sanitary ware with the lanthanum content (mass%) measured by XRF, it was confirmed that the latter was higher. This indicates that the lanthanum content near the surface of the antiviral glaze layer is higher than the lanthanum content in the entire antiviral glaze layer. In other words, this indicates that lanthanum is concentrated near the surface of the antiviral glaze layer. Therefore, according to the present invention, the antiviral agent can be concentrated near the surface of the glaze layer, and as a result, good antiviral properties can be exhibited. Furthermore, according to the present invention, even a small amount of the antiviral agent can be concentrated near the surface of the glaze layer, so good antiviral properties are efficiently exhibited and, because the amount of the antiviral agent is small, the Si-O structure of the glaze layer is not affected, meaning that sanitary ware with excellent surface properties can be realized.

[0082] Light resistance (discoloration prevention ability) Furthermore, the light resistance (discoloration prevention ability) of the sanitary ware of Examples 1 to 15 was evaluated. Specifically, a weathering test was conducted using a sunshine carbon arc lamp weathering tester (manufactured by Atlas, USA) in accordance with JIS K5400-9-8 Sunshine Carbon Arc Method. The test time was 8 hours, and the L*, a*, and b* values ​​of the photocatalyst coated body before and after the test were measured using the SCE method, and the color difference: ΔE* = [(ΔL*) 2 +(Δa*) 2 +(Δb*) 2 ] 1 / 2 The color difference meter used was a color difference meter (Konica Minolta, CR-400). The results are shown in Table 5.

[0083] [Table 5]

[0084] Relationship between antiviral agent content, antiviral agent elution amount, and antiviral activity value In addition, the relationship between the content of the antiviral agent, the amount of elution of the antiviral agent, and the antiviral activity value in the sanitary ware of Examples 1 to 15 was confirmed. Figure 13A shows the relationship between the amount of lanthanum converted to lanthanum oxide (La2O3) (wt%) and the amount of lanthanum eluted (ppm) onto the glaze layer surface. Figure 13B shows the relationship between the amount of lanthanum eluted and antiviral activity value. Figure 14A shows the relationship between the amount of lanthanum converted to lanthanum oxide (La2O3) (wt%) and the atomic abundance (mass%) measured by XRF. Figure 14B shows the relationship between the atomic abundance (mass%) of lanthanum measured by XRF and antiviral activity value. 13 and 14, it was confirmed that a proportional relationship exists between the amount of lanthanum converted to lanthanum oxide (La2O3) (wt%) and the atomic abundance of lanthanum (mass%) measured by XRF, that a proportional relationship exists between the lanthanum content and the amount of lanthanum eluted onto the glaze layer surface, and that a proportional relationship also exists between the amount of lanthanum eluted and the antiviral activity value. The amount of yttrium eluted from the sanitary ware of Example 10 (sanitary ware provided with a glaze layer containing 4.8% by weight of yttrium) was 0.051 ppm.

[0085] Confirmation of the relationship between firing conditions, spinodal phase separation amount, and antiviral activity value The antiviral glaze slurry prepared in the above Preparation Example, with 10% by weight of lanthanum oxide added, was spray-coated onto the ceramic body test pieces. Then, they were fired in a kiln under the following conditions 1 to 3 to produce three types of sanitary ware A to C. Sanitary ware A: Firing condition 1 (firing temperature: 1200°C, total firing time: 10 hours) Sanitary ware B: Firing condition 2 (firing temperature: 1200°C, total firing time: 15 hours) Sanitary ware C: Firing condition 3 (firing temperature: 1200°C, total firing time: 20 hours) The antiviral activity values ​​of sanitary ware A to C are shown in Table 6 below. The state of lanthanum near the surface of the antiviral glaze layer of sanitary ware A to C is shown in Figures 15A to 15C.

[0086] [Table 6] Table 6 and Figures 15A to 15C show that, under the same conditions of the amount of lanthanum oxide added and the same firing temperature, sanitary ware A, which was produced with a short firing time, had high antiviral properties, and furthermore, lanthanum underwent spinodal phase separation near the surface of the glaze layer 20, and the phase-separated region was rich. On the other hand, sanitary ware B, which was produced with a long firing time, exhibited a mixture of binodal and spinodal phase separation and had lower antiviral properties than sanitary ware A, and sanitary ware C, which was also produced with a long firing time, had lower antiviral properties than sanitary ware A and B. Those skilled in the art can employ various methods to cause specific rare earth elements such as lanthanum to exist near the surface of the glaze layer 20 through spinodal phase separation, in addition to adjusting the particle size and firing time as described above. [Explanation of symbols]

[0087] 1 sanitary ware, 10 ceramic base, 20 (top) glaze layer, 30 base glaze layer

Claims

1. Sanitary ware comprising a ceramic body and a glaze layer formed on the surface of the ceramic body, The aforementioned glaze layer contains a glaze material and a metal element as an antiviral agent that is not a metal element contained in the glaze material, and has an antiviral activity value of 2 or more as determined by the following [test method] in accordance with ISO 21702. The glaze material comprises 52 to 76% by weight of SiO₂, 6 to 14% by weight of Al₂O₃, 11.4 to 27.6% by weight of a divalent metal oxide, and 1.5 to 6.5% by weight of a monovalent metal oxide, wherein the divalent metal oxide comprises CaO, MgO, and ZnO, and the monovalent metal oxide comprises Na₂O and K₂O. The metal element used as the antiviral agent exists in a spinodal phase state at least on the surface of the glaze layer, thereby enabling the glaze layer to have an antiviral activity value of 2 or more as determined by the following [test method] in accordance with ISO 21702, characterized in that: [Test Method] - 0.4 mL of bacteriophage Qβ solution is dropped onto the aforementioned sanitary ware and, as a control, onto sanitary ware whose glaze layer does not contain an antiviral agent, and then covered with a film. - Leave each sanitary ware item to stand at 25°C for 24 hours. After standing, the bacteriophage Qβ was washed out and collected from each sanitary ware container, and then the viral infectivity titer was measured. The antiviral activity value is calculated using the following formula. R = Ut - At R: Antiviral activity value Ut: Common logarithm of the viral infectivity titer (PFU / cm²) of control sanitary ware after 24 hours of standing. At: The common logarithm of the viral infectivity titer (PFU / cm²) of the sanitary ware after 24 hours of standing.

2. The sanitary ware according to claim 1, characterized in that the antiviral agent exists in a spinodal phase separation state in a region with a depth of 10 nm from the surface of the glaze layer toward the ceramic body.

3. The sanitary ware according to claim 1 or 2, wherein the antiviral agent is a rare earth metal element.

4. The sanitary ware according to claim 1 or 2, further comprising a base glaze layer between the ceramic body and the glaze layer.

5. The sanitary ware according to claim 3, further comprising a base glaze layer between the ceramic body and the glaze layer.

Images