Antiviral agent containing yttrium or an yttrium compound, glaze containing said antiviral agent, and antiviral sanitary ware glazed with said glaze

Abstract

To provide an antiviral agent containing yttrium or a yttrium compound, an antiviral glaze that utilizes the antiviral properties of the yttrium or yttrium compound, and a sanitary ware including an antiviral glaze layer composed of the fired glaze.SOLUTION: A glaze containing a yttrium compound as a starting material is fired to give an yttrium-containing glaze layer, which exhibits antiviral properties.SELECTED DRAWING: Figure 3B

Description

[Technical Field]

[0001] The present invention relates to an antiviral agent containing yttrium or an yttrium compound, a glaze containing the antiviral agent, and antiviral sanitary ware glazed with the glaze. [Background technology]

[0002] There have been reports of composite oxides being given antiviral properties, and WO2020 / 017493A1 (Patent Document 1) 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).

[0003] Although Patent Document 1 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).

[0004] In addition, Cosmetology Research Report Vol. 28, 2020, pp. 43-52 (Non-Patent Document 1), written by the inventor of Patent Document 1, 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).

[0005] There have also been reports of imparting antiviral properties to liquid compositions, and Japanese Patent Laid-Open Publication No. 2020-111546 (Patent Document 2) 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 2 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 sanitary ware.

[0006] On the other hand, a glaze layer is formed on the outermost surface of sanitary ware 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 3) discloses sanitary ware having a base glaze layer and a top glaze layer containing a nanosilver antibacterial agent. However, Patent Document 3 does not consider sanitary ware with antiviral properties.

[0007] Japanese Patent Laid-Open Publication No. 2000-159619 (Patent Document 4) reports that forming a film of yttrium (Y) oxide or a film of Y oxide and cerium (Ce) oxide on the surface of a tile reduces the buildup of water scale and provides antifouling properties. According to Patent Document 4, Y has a high contact angle with water, providing good water repellency and hardness suitable for the durability required of sanitary ware such as tiles. Patent Document 4 also discloses that providing a glaze layer between the tile and the Y oxide film or Y / Ce oxide film (i.e., separate from the Y oxide film or Y / Ce oxide film) and adding an antibacterial agent (silver, copper, or zinc atoms, a quaternary amine, titanium oxide, zinc oxide, etc.) to this glaze layer improves antifouling properties. As can be understood from the disclosure of such reference 4, the reference merely discloses sanitary ware having stain-resistant properties that utilize the hardness and water-repellent properties of yttrium, and therefore the reference does not disclose or suggest in any way the technical idea that yttrium has antibacterial or even antiviral properties.

[0008] To date, there have been no reports that yttrium, a rare earth element, has antiviral properties. Furthermore, adding additives to glazes generally roughens the surface of sanitary ware, which can be undesirable from the standpoint of stain resistance or design. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] WO2020 / 017493A1 publication [Patent Document 2] Japanese Patent Publication No. 2020-111546 [Patent Document 3] CN111393188A publication [Patent Document 4] Japanese Patent Application Laid-Open No. 2000-159619 [Non-patent literature]

[0010] [Non-Patent Document 1] Cosmetology Research Report Vol.28,2020,pp.43-52 Summary of the Invention [Problem to be solved by the invention]

[0011] The present inventors have now experimentally confirmed that yttrium has antiviral properties. Specifically, they have experimentally confirmed that a glaze layer containing yttrium obtained by firing a glaze containing an yttrium compound as a starting material exhibits antiviral properties, and further confirmed that the yttrium in the glaze layer alone exhibits practical antiviral properties. The present invention is based on these findings.

[0012] Therefore, an object of the present invention is to provide an antiviral agent containing yttrium or an yttrium compound. Another object of the present invention is to provide an antiviral glaze that utilizes the antiviral properties of yttrium or an yttrium compound, and sanitary ware that includes an antiviral glaze layer obtained by firing the glaze. [Means for solving the problem]

[0013] The antiviral agent according to the present invention is characterized by containing yttrium or an yttrium compound as an active ingredient. The glaze according to the present invention is characterized in that it contains yttrium or an yttrium compound as an antiviral agent. The sanitary ware according to the present invention is A pottery body and a glaze layer formed on the surface of the pottery body, The glaze layer is characterized by containing yttrium (Y) as an antiviral agent. [Effects of the Invention]

[0014] The present invention provides an antiviral agent containing yttrium or an yttrium compound. The present invention also provides an antiviral glaze that utilizes the antiviral properties of yttrium or an yttrium compound, and sanitary ware that includes an antiviral glaze layer obtained by firing the glaze. [Brief explanation of the drawings]

[0015] [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 the XRD pattern of a glaze layer containing yttrium. [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 yttrium (Y) is present in a spinodal phase separation state on the surface of the glaze layer. [Figure 3B] 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. DETAILED DESCRIPTION OF THE INVENTION

[0016] 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.

[0017] Furthermore, with regard to the present invention, the expression "yttrium in the glaze layer alone" exhibits practical antiviral properties means that, while the composite oxide disclosed in Patent Document 1 exhibits antiviral properties by being made of lanthanum and other metal elements (Mo, W), and the liquid composition disclosed in Patent Document 2 exhibits antiviral properties by containing a rare earth salt and other metal salt (zinc salt), yttrium itself exhibits practical antiviral properties.

[0018] Antiviral agent and sanitary ware according to the present invention As described above, the present invention was made by discovering that yttrium has antiviral properties, i.e., a new performance, effect, or use of yttrium. According to one aspect of the present invention, sanitary ware containing the antiviral agent of the present invention is provided. Below, the antiviral agent of the present invention will be described in detail together with the sanitary ware of the present invention.

[0019] Sanitary ware As shown in FIG. 1A, a sanitary ware according to one embodiment of the present invention includes at least a ceramic body 10 and a glaze layer 20 containing yttrium as an antiviral agent formed on the surface thereof.

[0020] Sanitary ware 1 according to one embodiment of 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 (yttrium). 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 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 ceramic bodies.

[0021] 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.

[0022] Glaze layer In the present invention, the glaze layer 20 contains, as its components, an antiviral agent and a glaze material that can achieve the surface properties described below together with the antiviral agent.

[0023] antiviral agents In the present invention, the antiviral agent is yttrium (Y).

[0024] The yttrium contained in the glaze layer 20 inactivates viruses attached to the surface of the glaze layer. According to a preferred embodiment of the present invention, yttrium is dissolved on the surface of the glaze layer and ionized in a chemically stable state (Y 3+ ) inactivates viruses attached to the surface of the glaze layer. In this way, the glaze layer 20 can exhibit practical antiviral properties.

[0025] In the present invention, the antiviral property of the sanitary ware provided with the glaze layer 20 containing yttrium 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.

[0026] <Antiviral test method> 0.4 mL of the virus solution was dropped onto the test pieces (a sanitary ware test piece with a glaze layer containing yttrium and a control (a sanitary ware test piece with a glaze layer not containing the antiviral agent)) and 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 yttrium after leaving it for 24 hours 2 )

[0027] In the present invention, the antiviral activity of sanitary ware equipped with a glaze layer 20 containing yttrium can be expressed as an index using the antiviral activity value (V) determined in accordance with 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.

[0028] Antiviral activity value: V=Log 10 (UV / TV) TV: Bacteriophage infectivity titer (pfu) of sanitary ware with a glaze layer containing yttrium 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.

[0029] In the present invention, the glaze layer 20 containing yttrium 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.

[0030] In the present invention, the amount of yttrium eluted on the surface of the glaze layer 20 is preferably at least about 0.05 ppm in order to exhibit practical virus activity. In a preferred embodiment of the present invention, the amount of yttrium dissolved is approximately 1 to 2% of the yttrium content in a region 10 nm deep from the surface of the glaze layer toward the ceramic body (the direction of the arrow shown in FIG. 1).

[0031] In the present invention, the glaze layer 20 only needs to contain yttrium, and the content of yttrium is not particularly limited. However, in a preferred embodiment of the present invention, the content of yttrium contained in the glaze layer 20 is 2% by weight or more, calculated as yttrium oxide (Y2O3), when the total of the yttrium constituting the glaze layer 20 and the other glaze materials described below is taken as 100% by weight. By containing 2% by weight or more of yttrium, calculated as yttrium oxide (Y2O3), the glaze layer 20 can exhibit practical antiviral properties. It goes without saying that the amount of yttrium oxide (Y2O3) can be stoichiometrically converted to the weight percentage of yttrium.

[0032] In another preferred embodiment of the present invention, the content of yttrium in the glaze layer 20 can also be quantified by analyzing the glaze layer 20 by X-ray fluorescence spectroscopy (XRF). In the present invention, the atomic abundance (mass%) of yttrium in the glaze layer 20 is 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 above scanning X-ray fluorescence analyzer has a measurement limit of a region from the 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 shown in FIG. 1). Therefore, in the present invention, the quantification of yttrium using the above scanning X-ray fluorescence analyzer identifies the glaze layer 20 by determining the yttrium content (mass %) in a region from the surface of the glaze layer 20 to a depth of approximately 50 μm.

[0033] The atomic abundance of yttrium measured by X-ray fluorescence spectroscopy (XRF) has the advantage of being able to accurately measure the yttrium content in a region extending from the surface (0 μm) of the glaze layer 20 to a depth of approximately 50 μm toward the ceramic body, i.e., the yttrium content in the vicinity of the surface of the glaze layer 20. That is, the yttrium content in terms of yttrium oxide, as already explained, represents the yttrium content (percentage) in the entire glaze layer 20, and the yttrium content measured by X-ray fluorescence analysis (XRF) pinpoints and accurately represents the yttrium content near the surface of the glaze layer 20. In addition, the yttrium content measured by X-ray fluorescence analysis (XRF) is useful for accurately determining the amounts of various compounds, such as yttrium oxide and chloride, to be added as starting materials for the antiviral agent, based on stoichiometry.

[0034] Other glaze materials Glaze layer 20 contains yttrium as well as materials typically used in glazes, such as SiO2, Al2O3, divalent metal oxides, and monovalent metal oxides. 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%.

[0035] 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.

[0036] In the present invention, preferred compositions of glaze materials other than yttrium are, for example, as shown in Table 1 below.

[0037] [Table 1]

[0038] State of yttrium (antiviral agent) in the glaze layer 20 In the present invention, it is preferable that yttrium exists in an amorphous (non-crystalline) state at least on the surface of the glaze layer 20. By having yttrium exist in an amorphous state on the surface of the glaze layer 20, the yttrium can be efficiently ionized and eluted onto the surface of the glaze layer, making it possible to efficiently inactivate viruses adhering to the surface of the glaze layer. Furthermore, because yttrium exists in an amorphous state, it is possible to suppress the influence on the surface properties of the glaze layer surface.

[0039] In the present invention, it is more preferable that yttrium is present in a vitrified state at least on the surface of the glaze layer 20. By having yttrium present in a vitrified state on the surface of the glaze layer 20, the yttrium can be more efficiently ionized and eluted onto the surface of the glaze layer, making it possible to more efficiently inactivate viruses adhering to the surface of the glaze layer. Furthermore, because yttrium is present in a vitrified state, it is possible to reduce the impact on the surface properties of the glaze layer surface.

[0040] The presence of yttrium in an amorphous (non-crystalline) state, preferably 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: 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

[0041] In the present invention, it is even more preferable that yttrium undergoes spinodal phase separation at least on the surface of 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 specific lanthanoid is more likely to stably elute to the surface of the glaze layer, and even if the specific lanthanoid is present on the surface of the glaze layer, its effect on the surface properties of the glaze layer is further suppressed. In particular, with regard to elution, by spinodal phase separation of yttrium on the surface of the glaze layer 20, yttrium can be stably ionized and eluted from the surface of the glaze layer, making it possible to more efficiently inactivate viruses attached to the surface of the glaze layer and exhibit high antiviral properties.

[0042] As described below, spinodal phase separation of yttrium is achieved by firing the ceramic body 10 and the glaze that forms the glaze layer 20 together once, followed by cooling. Specifically, by firing the ceramic body 10 and the glaze that forms the glaze layer 20 together once and then cooling, it is possible to induce a glass phase separation phenomenon. Glass phase separation is a phenomenon in which a single-phase glass separates into multiple phases. When glass consisting of multiple components exists in 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 separates into two phases because it is thermodynamically more stable when separated into two phases.

[0043] In the present invention, a glaze composed of multiple components, such as SiO2, metal oxides, and yttrium oxide, 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 two regions: (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, unentangled with the other. In the spinodal region, one of the two phases formed by phase separation exists as a dispersed nonspherical particle, highly entangled with the other. Theoretically, yttrium 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 and cooling them, it is possible to make yttrium abundant near the surface of the glaze layer, and to make the proportion of yttrium present near the surface of the glaze layer in the spinodal phase-separated state higher than the proportion of yttrium present in the binodal phase-separated state, although the details of the mechanism are unclear. This has been confirmed by experiments, as will be described later. For example, as shown in Figure 3, yttrium is abundant near the surface of the glaze layer 20, and this yttrium is present in a spinodal phase-separated state.

[0044] It is believed that the mode in which yttrium exists in a spinodal phase separation state near the surface of the glaze layer also includes a state in which an yttrium-rich phase is intertwined with a non-yttrium-rich phase (-Si-O- structure), or a state in which an yttrium-rich portion is more intertwined with a non-yttrium-rich portion (i.e., exists uniformly with higher resolution), and a state in which an yttrium-rich portion cooperates with other portions in the glass matrix structure of the glaze layer surface to form an entangled structure as a whole. The presence of yttrium near the surface of the glaze layer in such a state enables or promotes the macroscopic uniform elution of yttrium from the glaze layer surface, which is believed to result in high antiviral properties.

[0045] It should be noted that the present invention requires that a region where yttrium has undergone spinodal phase separation be present on the surface of the glaze layer 20 within the scope of the effects of the present invention, and does not exclude an embodiment in which the region where yttrium has undergone binodal phase separation is present at a lower ratio than the region where yttrium has undergone spinodal phase separation due to, for example, unavoidable circumstances in the process of manufacturing the glaze layer 20, within the scope of not impeding the effects of the present invention.

[0046] Furthermore, since yttrium is present in a spinodal phase separation state on the surface of the glaze layer 20, scattering at the interface between the two phases causes the glaze layer to assume a white color, making it possible to realize a glaze layer surface with excellent image clarity, as described below. In addition, since yttrium is present in a spinodal phase separation state on the surface of the glaze layer 20, an yttrium-rich phase is uniformly present on the surface, allowing yttrium to be stably eluted, resulting in high antiviral properties.

[0047] surface texture 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.

[0048] 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.

[0049] 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).

[0050] 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.

[0051] A DOI value of 80 or more 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 the adhesion of filth, including viruses, and thus preventing the adhesion of filth from being left unattended. According to a preferred embodiment of the present invention, the DOI value of the surface of the glaze layer 20 is 85 or more.

[0052] 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).

[0053] 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.

[0054] 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.

[0055] Manufacturing method The sanitary ware according to the present invention can be preferably produced by the following method.

[0056] 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.

[0057] A glaze slurry for forming the glaze layer 20, that is, a glaze slurry containing an yttrium compound as a raw material for the antiviral agent and other glaze materials, is prepared. The composition of the glaze materials other than the yttrium compound is, for example, as shown in Table 1 above. Furthermore, as the yttrium compound, for example, a compound having a boiling point of 1000° C. or higher, such as an oxide of yttrium, can be used, more preferably a compound having 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.

[0058] 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 using, for example, a ball mill to obtain a glaze slurry precursor. An yttrium 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 yttrium compound is added to this frit raw material, and then water, a dispersion medium, and other raw materials (such as pottery stone and ZnO) are 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.

[0059] 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 yttrium compound after pulverization is approximately the same as the average particle size of the glaze material after pulverization (including other raw materials in the second embodiment). For example, it is preferable that the average particle sizes of the yttrium 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 a laser diffraction method. Furthermore, the average particle sizes being "approximately the same" means that the ratio (former / latter) of the average particle size of the yttrium compound to the average particle size of the glaze material is within the range of 0.9 to 1.1.

[0060] By adjusting the average particle size of the yttrium compound and the glaze material in this way, it is possible to cause spinodal phase separation of yttrium on the surface of the glaze layer 20, and also to achieve the above-mentioned surface properties (Ra, DOI value, ΔE* value).

[0061] 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.

[0062] 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 yttrium. 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. It is preferable to perform the firing together only once. The inventors have experimentally confirmed that performing the firing together only once suppresses the crystallization of yttrium. Specifically, they have confirmed that multiple firings cause crystals to precipitate from the amorphous layer of the glaze layer; for example, performing the second firing at a temperature lower than the first firing temperature causes crystals to precipitate.

[0063] 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.

[0064] The ceramic body 10 and a glaze slurry prepared so that the average particle size of the yttrium compound is approximately the same as that of the other glaze materials are fired together once at a temperature lower than the melting point of yttrium, and then cooled, whereby the crystallization of yttrium is suppressed, and the glaze layer 20 is preferably vitrified, more preferably converted into a glass liquid phase (glass melt), even more preferably subjected to phase separation of the glass melt, and most preferably subjected to spinodal phase separation, resulting in a glaze layer 20 having an abundant region of yttrium spinodally separated on its surface. [Example]

[0065] The present invention will be specifically described based on the following examples, but the present invention is not limited to these examples.

[0066] Making pottery base A 70mm x 150mm plate-shaped test piece was prepared using ceramic slurry prepared from silica sand, feldspar, clay, etc.

[0067] 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.

[0068] [Table 2]

[0069] 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 was 65% 10 μm or less and the 50% particle size (D50) was 6.5 μm. This glaze slurry precursor was then mixed with 1 wt. %, 2.5 wt. %, 5 wt. %, and 10 wt. % yttrium oxide (i.e., 1 wt. %, 2.5 wt. %, 5 wt. %, and 10 wt. % yttrium oxide were added to the glaze slurry precursor (i.e., 100 wt. % of the total glaze material). The mixture was then pulverized in a ball mill so that the particle size was 65% 10 μm or less and the 50% particle size (D50) was 6.5 μm. The antiviral glaze slurries for sanitary ware of Examples 1 to 4 were prepared. Furthermore, a glaze slurry for sanitary ware of Comparative Example 1 was prepared in the same manner as above, except that 5% by weight of cerium oxide was added instead of 5% by weight of yttrium oxide.

[0070] [Table 3]

[0071] Sanitary ware manufacturing The glaze slurries for Examples 1 to 4 prepared as described above were spray-coated onto the ceramic body test pieces. After that, the pieces were fired once together at 1200°C in a kettle and cooled to produce the sanitary ware of Examples 1 to 4 and Comparative Example 1.

[0072] evaluation Examples The sanitary wares of Examples 1 to 4 and Comparative Example 1 were evaluated as follows.

[0073] Antiviral content The yttrium content, calculated as an yttrium oxide equivalent, contained in the glaze layers of the sanitary ware of Examples 1 to 4, for example, for the sanitary ware of Example 1, is calculated as 1 wt% / (100 wt% + 1 wt%) × 100 ≒ 0.99%, where 1 wt% is the percentage of yttrium oxide relative to the total (101 wt%) of 100 wt% of the glaze material and 1 wt% of yttrium oxide shown in Table 3. The same applies to Examples 2 to 4 and Comparative Example 1.

[0074] 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 4, Comparative Example 1, and 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: Virus infectivity (PFU / cm) of the sanitary ware of Examples 1 to 4 and Comparative Example 1 after standing for 24 hours 2 ) The antiviral activity values ​​of the sanitary ware of Examples 1 to 4 and Comparative Example 1 are shown in Table 4. Furthermore, the amounts of yttrium eluted from the sanitary ware of Examples 1 to 4 were 0.015 ppm, 0.037 ppm, 0.051 ppm, and 0.1 ppm, respectively. Average roughness (Ra) The center line average roughness (μm) defined by JIS-B0601 (1994) was determined using a stylus surface roughness measuring device (JIS-B0651). The results are shown in Table 4.

[0075] DOI value Wave Scan DOI measuring device: The DOI value was measured using the Wave-ScanDIO (orange peel measuring device) manufactured by BYK Gardner (Germany). The results were as shown in Table 4.

[0076] From the results shown in Table 4, in the sanitary ceramics of Comparative Example 1 containing Ce, the antiviral activity value was low and the surface properties (Ra value and DOI value) were also poor. On the other hand, in the sanitary ceramics of Examples 1 to 4, it was confirmed that all had higher antiviral activity than Comparative Example 1 and had good surface properties (Ra value and DOI value). That is, it was confirmed that the sanitary ceramics according to the present invention have both antiviral properties and excellent stain non-adhesiveness and easy removability, and these performances are synergistically exhibited.

[0077] Confirmation of the state of yttrium near the surface of the glaze layer <XRD measurement> XRD device: Measurement was carried out using <X'Pert PRO> manufactured by PANalytical under the following conditions. XRD measurement conditions Measurement range: 3° to 60° Scan rate: 4° / min Applied voltage: 45V, applied current: 40mA Figure 2 shows the XRD pattern of the glaze layer of the sanitary ceramics of Example 3. As shown in Figure 2, no peak was observed in the XRD measurement of the surface of the antiviral glaze layer containing yttrium (4.76% by weight). Therefore, it was confirmed that yttrium exists in an amorphous or vitrified state on the surface of the antiviral glaze layer.

[0078] <SEM observation, TEM observation> The presence of yttrium near the surface of the antiviral glaze layer was observed using SEM and TEM. SEM observations were 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 observations were 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 and 3B. In Figure 3A, the white areas indicate the presence of yttrium, and the black areas indicate Si-O structures. In Figure 3B, the black areas indicate the presence of yttrium, and the white areas indicate Si-O structures. The black areas that resemble borders indicate the presence of yttrium-rich regions. The image area above the black boundary line is an air area and is therefore not subject to observation. 3A and 3B, it was confirmed that yttrium was present in abundance near the surface of the antiviral glaze layer, that this yttrium underwent spinodal phase separation, and that the amount of spinodal phase separation of this yttrium was abundant.

[0079] Light resistance (discoloration prevention ability) 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 photocatalytic coating before and after the test were measured using the SCE method, and the color difference was calculated as 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 4.

[0080] [Table 4] [Explanation of symbols]

[0081] 1 sanitary ware, 10 ceramic base, 20 (top) glaze layer, 30 base glaze layer

Claims

1. A sanitary ware comprising a ceramic body and a glaze layer formed on the surface of the ceramic body, The glaze layer contains yttrium oxide (Y) when the total of the yttrium constituting the glaze layer and the glaze materials other than the yttrium is taken as 100% by weight. ２ O ３ ) and has an antiviral activity value of 2 or more as determined by the following [Test Method] in accordance with ISO 21702, A sanitary ware characterized in that yttrium is present in an amorphous (non-crystalline) state at least on the surface of the glaze layer. [Test Method] 0.4 mL of bacteriophage Qβ liquid was dropped onto the sanitary ware and, as a control, onto a sanitary ware whose glaze layer did not contain an antiviral agent, and then covered with a film. - Leave each sanitary ware at 25°C for 24 hours. After leaving the sanitary ware to stand, the bacteriophage Qβ on each piece of sanitary ware is washed and collected, and then the viral infectivity is measured. ・ Calculate the antiviral activity value using the following formula: R = Ut - At R: Antiviral activity value Ut: Virus infectivity of control sanitary ware after standing for 24 hours (PFU / cm ２ ) common logarithm At: viral infectivity of the sanitary ware after standing for 24 hours (PFU / cm ２ ) is the base 10 logarithm of

2. 2. The sanitary ware according to claim 1, wherein the glaze layer has a surface roughness (Ra) of 0.07 μm or less.

3. 3. The sanitary ware according to claim 1, wherein the glaze layer has a surface with a DOI value of 80 or more as measured by a Wavescan DOI measuring device.

4. The sanitary ware according to any one of claims 1 to 3, wherein the yttrium undergoes spinodal phase separation at least on the surface of the glaze layer.

5. The sanitary ware according to any one of claims 1 to 4, further comprising a base glaze layer between the ceramic body and the glaze layer.

6. A method for producing the sanitary ware according to any one of claims 1 to 5, The process of preparing the pottery base, preparing a glaze slurry containing yttrium and glaze materials other than the yttrium; applying the glaze slurry to the surface of the ceramic body; A process of firing the pottery body to which the glaze slurry has been applied to form a glaze layer; A method comprising at least

7. 7. The method of claim 6, wherein the calcination is carried out at a temperature below the melting point of yttrium.

8. 8. The method according to claim 6, wherein the ratio of the average particle size of the yttrium to the average particle size of the glaze material (the former / the latter) is in the range of 0.9 to 1.

1.

9. The method according to any one of claims 6 to 8, further comprising the step of forming a base glaze layer on the surface of the ceramic body, and applying the glaze slurry to the surface of the base glaze layer.

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