Sanitary ware

Abstract

To provide a sanitary ware including a glaze layer 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, as an antiviral agent, lanthanoid or a lanthanoid compound. The glaze layer has a surface roughness (Ra) of 0.07 μm or less. The lanthanoid is at least one selected from the group consisting of 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). 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 ceramics, and more particularly to sanitary ceramics having both antiviral properties and resistance to dirt adhesion and easy removability.

Background Art

[0002] In sanitary ceramics, a glaze layer is formed on its outermost surface in order to ensure a hygienic surface and also to ensure the appearance design. In order to improve the sanitary surface, a technique of adding an antibacterial agent to the glaze layer has been proposed. For example, Patent Document 1 (CN111393188A) discloses sanitary ceramics including a base glaze layer and a top glaze layer containing a nano-silver antibacterial agent.

[0003] In addition, an example of imparting antiviral properties to a composite oxide has been reported. Patent Document 2 (WO2020 / 017493A1) suggests that composite oxide ceramics containing a rare earth element and other specific metal elements have both water repellency and antibacterial and antiviral properties. Specifically, it is disclosed that a calcined powder (500 ° C) of composite oxide ceramics (LMO) containing lanthanum (La) and molybdenum (Mo) exhibits higher activity against bacteriophage Qβ and Φ6 than a single oxide (La2O3 particles) (paragraphs 0067, 0069-0071, FIG. 8).

[0004] In Patent Document 2, although a comparison with a single oxide has not been confirmed, it is disclosed that calcined powders (500 ° C, 400 ° C, or 550 ° C) of composite oxide ceramics (LMO, LWO, LCMO (a part of La in LMO is substituted with cerium (Ce)), LMWO (a part of Mo in LMO is substituted with W)) containing lanthanum (La) and molybdenum (Mo) and / or tungsten (W) exhibit activity against bacteriophage Qβ and Φ6 (FIGS. 11, 14-17, 20).

[0005] In addition, the same content as that of Patent Document 2 is also disclosed in the cosmetology research report Vol.28, 2020, p43-52 (Non-Patent Document 1) written by the inventor of Patent Document 2. For bacteriophages Qβ and Φ6, CeO2 shows almost no activity, while La2O3 shows certain activity. On the other hand, it is disclosed that the anti-Qβ and Φ6 activities of La2O3 are lower than those 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. In Japanese Patent Application Laid-Open No. 2020-111546 (Patent Document 3), an antiviral composition containing a rare earth salt, a zinc salt, and water is proposed. Specifically, an aqueous solution containing lanthanum chloride, cerium chloride, neodymium chloride, or ytterbium acetate and zinc gluconate has a lower virus infectivity titer (Log(PFU)), that is, higher antiviral properties, compared to 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 processing it into ceramic materials and further into glaze materials is not described.

[0007] So far, no examples have been reported that rare earth elements such as La, especially lanthanoids, alone have antiviral properties that can withstand practical use. On the other hand, due to the recent COVID-19 pandemic and the like, the need for sanitary ceramics with practical antiviral properties has been increasing. Furthermore, generally, when additives are added to glazes, the surface of sanitary ceramics becomes rough, which may not be desirable from the viewpoints of antifouling properties or design.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Non-Patent Document

[0009]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0010] The inventors of the present invention have now experimentally confirmed that, as a component of the glaze layer of sanitary ware, lanthanoids, preferably lanthanoids present in a specific state in the glaze layer, exhibit practical antiviral properties alone. Furthermore, it has been confirmed that a glaze layer containing such lanthanoids or lanthanoid compounds not only exhibits good antiviral properties but also maintains excellent surface properties in terms of resistance to fouling and ease of removal (the property of being difficult to adhere to dirt and easy to remove) in the coexistence with other components. The present invention is based on such findings.

[0011] Therefore, an object of the present invention is to provide a sanitary ware having a glaze layer that combines practical antiviral properties and resistance to fouling and ease of removal.

Means for Solving the Problems

[0012] And the sanitary ware according to the present invention comprises a ceramic body and a glaze layer formed on the surface of the ceramic body, the glaze layer contains lanthanoids as an antiviral agent, the surface roughness (Ra) of the glaze layer is 0.07 μm or less, The lanthanoid is at least one selected from the group consisting of 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), excluding cerium (Ce), europium, and promethium (Pm).

Advantages of the Invention

[0013] According to the present invention, there is provided a sanitary ceramic ware having a glaze layer with practical antiviral properties and resistance to dirt adhesion and easy removability of dirt.

Brief Description of the Drawings

[0014]

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Mode for Carrying Out the Invention

[0015] Definition In the present invention, "sanitary pottery" means pottery products used around toilets and washrooms, specifically including flush toilets, urinals, toilet bowls, toilet tanks, washbasins in washstands, and washbasins for handwashing. Also, "pottery" means among ceramics, those with a slightly absorbent texture due to the firing of the body and with a glaze applied to the surface.

[0016] Regarding the present invention, when it is said that a lanthanoid or a lanthanoid compound "alone" exhibits practical antiviral properties, it means that, in contrast to the composite oxides disclosed in Patent Document 2, which exhibit antiviral properties because they are composed of lanthanum and other metal elements (Mo, W), and in contrast to the liquid composition disclosed in Patent Document 3, which exhibits antiviral properties because it contains a rare earth salt and other metal salts (zinc salts), the lanthanoid or the lanthanoid compound itself exhibits practical antiviral properties.

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

[0018] The sanitary pottery 1 according to the present invention may further comprise one or more other glaze layers between the pottery body 10 and the glaze layer 20 containing an antiviral agent. For example, according to one aspect of the present invention, as shown in FIG. 1B, the sanitary pottery 1 comprises a pottery body 10, a glaze layer 30 formed on the surface of the pottery body 10, and a glaze layer 20 containing an antiviral agent formed on the surface of the glaze layer 30. In the present invention, the glaze layer 30 may also be referred to as a base glaze layer and the glaze layer 20 as an antiviral glaze layer. The base glaze layer 30 is not particularly limited and may be a glaze layer that is usually applied to a pottery body.

[0019] Body of pottery The pottery body 10 is not particularly limited and may be a conventionally known pottery body. That is, it may be appropriately formed from a sanitary pottery body slurry prepared using silica sand, feldspar, clay, etc. as raw materials.

[0020] Glaze layer In the present invention, the glaze layer 20 contains, as its components, an antiviral agent and a glaze material capable of realizing the surface properties described below together with the antiviral agent.

[0021] Antiviral agent In the present invention, the antiviral agent is at least one lanthanoid selected from the group consisting of 12 elements of 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 a lanthanoid excluding cerium (Ce), europium (Eu), and promethium (Pm) (hereinafter, the above 12 lanthanoids excluding Ce, Eu, and Pm may also 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.

[0022] In the present invention, the reason for excluding Ce and Eu from the lanthanoids is that only these two atoms among the lanthanoids have two valences stably. That is, the Ce atom stably takes two types of valences of +3 and +4, and the Eu atom stably takes two types of valences of +2 and +3. Therefore, by donating electrons to the Si-O bond of the glaze layer 20, it affects the Si-O bond such as stretching the Si-O bond, that is, it affects the vitrified structure of the glaze layer 20, and as a result, the surface of the glaze layer 20 becomes rough. For this reason, the surface properties described below cannot be realized, and it is inappropriate as a component contained in the glaze layer 20. In other words, when imparting antiviral properties to the glaze layer of sanitary pottery, it is preferable to adopt an antiviral agent that has little influence on the Si-O bond. In the present invention, the reason for excluding Pm from the lanthanoids is that this atom does not exist stably among the lanthanoids, has radioactivity, and has greatly different physical properties from other lanthanoids.

[0023] The specific lanthanoid contained in the glaze layer 20 inactivates the virus attached to the surface of the glaze layer. According to a preferred embodiment of the present invention, the specific lanthanoid eluted on the surface of the glaze layer and ionized in a chemically stable state inactivates the virus attached to the surface of the glaze layer. In this way, the glaze layer 20 can exhibit good antiviral properties.

[0024] In the present invention, the antiviral property of the sanitary pottery provided with the glaze layer 20 containing the specific lanthanoid can be represented by using the antiviral activity value against bacteriophage Qβ as an index. The antiviral activity value can be determined, for example, by the following test method in accordance with ISO 21702.

[0025] <Antiviral Test Method> · Drop 0.4 mL of the virus solution onto the test pieces (test pieces of sanitary pottery provided with a glaze layer containing a specific lanthanoid and a control (test piece of sanitary pottery provided with a glaze layer not containing an antiviral agent)), and cover with a film. · Leave the test pieces standing at 25 °C for 24 hours. · After standing, wash out and collect the virus on the test pieces, and then measure the virus infectivity titer. · Calculate the antiviral activity value by the following formula and evaluate the antiviral property. R = Ut - At R: Antiviral activity value Ut: Common logarithm of the virus infectivity titer (PFU / cm 2 ) after standing the control for 24 hours At: Common logarithm of the virus infectivity titer (PFU / cm 2 ) after standing the test piece of sanitary pottery provided with a glaze layer containing a specific lanthanoid for 24 hours

[0026] In the present invention, the antiviral activity of the sanitary ware provided with the glaze layer 20 containing a specific lanthanoid can also be represented by using, as an index, the antiviral activity value (V) determined according to JIS R1756 visible light B condition, bright place. Specifically, an antiviral test is carried out using bacteriophage Qβ in accordance with JIS R1756 visible light B condition. Using a 20W white fluorescent lamp (manufactured by Toshiba Lighting & Technology Corporation, "Neo Line" FL20S·W) as a light source, visible light of 380 nm or more is irradiated at an illuminance of 500 lux through an ultraviolet cut filter (manufactured by Nitto Denko Corporation, N-169). The illuminance is measured using an illuminance meter: Topcon Corporation, IM-5. With the irradiation time of visible light being 4 hours, the antiviral activity value (V) of the bright place can be calculated by the following formula.

[0027] Antiviral activity value: V = Log 10 (UV / TV) TV: Bacteriophage infectivity titer (pfu) of the sanitary ware provided with the glaze layer containing a specific lanthanoid after light irradiation UV: Bacteriophage infectivity titer (pfu) per control after light irradiation Note that, as a control, sanitary ware provided with a glaze layer not containing an antiviral agent is used.

[0028] In the present invention, the glaze layer 20 containing a specific lanthanoid has an antiviral activity value of 2 to 6. The antiviral activity value of 2 or more satisfies the practical antiviral performance criteria in sanitary ware.

[0029] In a preferred embodiment of the present invention, when the total of the antiviral agent (specific lanthanoid) contained in the glaze layer 20 and other glaze materials described later is 100% by weight, the content of the specific lanthanoid in terms of oxide 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. Needless to say, it is possible to convert from the amount of the specific lanthanoid oxide to the weight% of the specific lanthanoid stoichiometrically.

[0030] In addition, the preferable content (in terms of oxide conversion) of the antiviral agent contained in the glaze layer 20 is as follows for each specific lanthanoid. Lanthanum (La): 1.0 wt% to 20.0 wt%, the upper limit is preferably about 14 wt%, more preferably 11 - 12 wt%, even more preferably about 9 wt%, and the lower limit is preferably 5 wt% or more. Praseodymium (Pr): 1.0 wt% to 20.0 wt%, the upper limit is preferably about 14 wt%, more preferably 11 - 12 wt%, 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 - 12 wt%, 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 - 13.2 wt%, 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 - 13.2 wt%, 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 - 13.2 wt%, 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 - 13.2 wt%, 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 - 14.4 wt%, 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%, 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%, even more preferably about 10.8 wt%, and the lower limit is preferably 6 wt% or more. Ytterbium (Yb): 1.2 wt% to 24.0 wt%, the upper limit is preferably about 16.8 wt%, more preferably 13.2 to 14.4 wt%, even more preferably about 10.8 wt%, and the lower limit is preferably 6 wt% 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%, even more preferably about 10.8 wt%, and the lower limit is preferably 6 wt% or more.

[0031] By containing a specific lanthanoid in the amount within the above-described range, the glaze layer 20 can exhibit better antiviral properties.

[0032] In the present invention, the content of the antiviral agent (specific lanthanoid) contained in the glaze layer 20 can also be quantified by analyzing the glaze layer 20 by X-ray fluorescence analysis (XRF). In the present invention, using a scanning X-ray fluorescence analyzer (Rigaku ZSX PrimusIV (manufactured by Rigaku Corporation)), the atomic abundance (mass%) of the specific lanthanoid contained in the glaze layer 20 can be determined under the following measurement conditions and analysis conditions. (Measurement conditions) Tube voltage: 60 kV Tube current: 50 mA Measurement depth: several tens of μm (about 0 to 50 μm) Measurement area: Φ20 mm (Analysis conditions) La detection line: La Lα (alpha) line, 2θ = 82.88 Spectrometer crystal: LiF(200) Detector: SC Note that, since the measurement limit of the above scanning fluorescence X-ray analyzer is a region with a depth of about 50 μm in the direction from the outermost surface (0 μm) of the glaze layer 20 toward the pottery body (the direction of the arrow shown in FIG. 1), in the present invention, the quantification of the specific lanthanoid using the above scanning fluorescence X-ray analyzer is based on the content (% by mass) of the specific lanthanoid in the depth region of about 50 μm from the outermost surface of the glaze layer 20, and identifies the glaze layer 20.

[0033] The atomic abundance of the specific lanthanoid measured by the fluorescence X-ray analysis method (XRF) has the advantage that it can accurately measure the content of the specific lanthanoid contained in a region with a depth of about 50 μm in the direction from the outermost surface (0 μm) of the glaze layer 20 toward the pottery body, that is, in the vicinity of the surface of the glaze layer 20. That is, the content of the specific lanthanoid in terms of the specific lanthanoid oxide described above represents the content ratio (percentage) of the specific lanthanoid in the entire glaze layer 20, and the content of the specific lanthanoid measured by the fluorescence X-ray analysis method (XRF) precisely and accurately represents the content ratio of the specific lanthanoid in the vicinity of the surface of the glaze layer 20. In addition, the content of the specific lanthanoid measured by the fluorescence X-ray analysis method (XRF) helps to accurately grasp the addition amounts of various compounds such as oxides and chlorides of the specific lanthanoid as starting materials for the antiviral agent based on stoichiometry.

[0034] Other glaze materials The glaze layer 20 contains materials usually used in glazes, such as SiO2, Al2O3, divalent metal oxides, and monovalent metal oxides, together with the antiviral agent (specific lanthanoid). According to a preferred embodiment of the present invention, the weight % of SiO2 with respect to the glass component is 52 to 76%, the weight % of Al2O3 with respect to the glass component is 6 to 14%, the weight % of the divalent metal oxide with respect to the glass component is 11.4 to 27.6%, and the weight % of the monovalent metal oxide with respect to the glass component is 1.5 to 6.5%.

[0035] The glaze layer 20 mainly consists of SiO2, Al2O3, divalent metal oxides, and monovalent metal oxides, but may also contain Fe2O3, TiO2, V2O5, etc. As the divalent metal oxides, alkaline earth metal oxides such as CaO and MgO, ZnO, CuO, etc. can be used. As the monovalent metal oxides, Na2O, K2O, Li2O, etc. can be used.

[0036] In the present invention, the preferred composition of other glaze materials other than the antiviral agent (specific lanthanoid) is as shown in Table 1 below, for example.

[0037]

Table 1

[0038] Existence state of the antiviral agent in the glaze layer 20 In the present invention, it is preferable that the antiviral agent (specific lanthanoid) exists in an amorphous state at least on the surface of the glaze layer 20. When the antiviral agent exists in an amorphous state on the surface of the glaze layer 20, the antiviral agent can be efficiently ionized and eluted on the surface of the glaze layer, and it becomes possible to efficiently inactivate the virus attached to the surface of the glaze layer. In addition, since it exists in an amorphous state, the influence on the surface properties of the glaze layer surface can be suppressed.

[0039] In the present invention, it is more preferable that the antiviral agent (specific lanthanoid) exists in a vitrified state at least on the surface of the glaze layer 20. When the antiviral agent exists in a vitrified state on the surface of the glaze layer 20, the antiviral agent can be more efficiently ionized and eluted on the surface of the glaze layer, and it becomes possible to more efficiently inactivate the virus attached to the surface of the glaze layer. In addition, since it exists in a vitrified state, the influence on the surface properties of the glaze layer surface can be suppressed.

[0040] That the antiviral agent (specific lanthanoid) exists 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 performing XRD measurement on the surface of the glaze layer 20. For example, using an XRD apparatus: <X’Pert PRO> manufactured by PANalytical, measurement is performed under the following conditions, and it is confirmed that no peak is observed, indicating that it is not crystalline, that is, it is in an amorphous (non-crystalline) state, preferably in a vitrified state. XRD Measurement Conditions Measurement Range: 3° to 60° Scan Rate: 4° / min Applied Voltage: 45V, Applied Current: 40mA

[0041] In the present invention, it is even more preferable that the antiviral agent (specific lanthanoid) 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 precipitation of particles due to crystallization in the glaze layer is suppressed. As a result, the specific lanthanoid is likely to stably elute on the surface of the glaze layer, and even when the specific lanthanoid is present on the surface of the glaze layer, the influence on the surface properties of the glaze layer is further suppressed. In particular, regarding elution, when the antiviral agent undergoes spinodal phase separation on the surface of the glaze layer 20, the antiviral agent can stably ionize and elute from the surface of the glaze layer, and it becomes possible to more efficiently inactivate the virus adhering to the surface of the glaze layer, thereby exhibiting high antiviral properties.

[0042] As will be described later, the spinodal phase separation of the antiviral agent is realized by integrally firing the pottery body 10 and the glaze forming the glaze layer 20 once and then cooling them. Specifically, by integrally firing and cooling the pottery body 10 and the glaze for forming the glaze layer 20 once, it becomes possible to induce the phase separation phenomenon of the glass. The phase separation of the glass refers to the phenomenon in which a single-phase glass separates into a plurality of phases. When a glass composed of a plurality of components exists as a uniform liquid phase (glass melt), as the temperature decreases, there is a region where the free energy is lower in the two-phase mixture state than in the single-phase state. The glass melt placed in such a region phase-separates because it becomes a thermodynamically stable state when separated into two phases.

[0043] In the present invention, a glaze composed of a plurality of components such as SiO2, metal oxides, and lanthanoid oxides becomes a uniform (single) glass liquid phase (glass melt) by firing. By cooling this glass melt to a temperature below the liquidus line in the phase equilibrium diagram of the glass, it is placed in a metastable immiscible region. In the metastable immiscible region, there are (i) a binodal region where the glass melt phase-separates by a nucleation-growth mechanism in which nuclei are generated and grow, and (ii) a spinodal region where the glass melt becomes thermodynamically unstable and phase-separates (spinodal decomposition mechanism) without nucleation. In the binodal region, one of the two phases formed by phase separation exists dispersed in spherical particles that are not intertwined with the other, and in the spinodal region, one of the two phases formed by phase separation exists dispersed in a non-spherical shape with a high degree of intertwining with the other. Theoretically, it is considered that a specific lanthanoid can take both the spinodal phase-separated state and the binodal phase-separated state in the glaze layer. In the present invention, by integrally firing and cooling the pottery substrate 10 and the glaze for forming the glaze layer 20, although the details of the mechanism are not clear, the specific lanthanoid can be richly present near the surface of the glaze layer, and the proportion of the lanthanoid present near the surface of the glaze layer in the spinodal phase-separated state can be made higher than the proportion in the binodal phase-separated state. This has been confirmed by experiments as described later. For example, as shown in FIGS. 2 to 11, near the surface of the glaze layer 20, the specific lanthanoid is richly present, and this specific lanthanoid exists in the spinodal phase-separated state. In addition, in the mode where the specific lanthanoid exists in the spinodal phase separation state near the surface of the glaze layer, the phase rich in the specific lanthanoid is present in an entangled state with the phase not rich in the specific lanthanoid (-Si-O- structure), or the part rich in the specific lanthanoid is present in a more entangled state (i.e., uniformly present with higher resolution) with the part not rich in the specific lanthanoid. It is considered that the state where the part rich in the specific lanthanoid in the glass matrix structure on the surface of the glaze layer forms an entangled structure as a whole in cooperation with other parts is also included. When the specific lanthanoid exists near the surface of the glaze layer in such a state, it is possible or promoted for the specific lanthanoid to elute macroscopically uniformly from the surface of the glaze layer. As a result, it is considered that high antiviral properties are exhibited.

[0044] In addition, in the present invention, as long as the region where the antiviral agent undergoes spinodal phase separation exists on the surface of the glaze layer 20 within the range where the effects of the present invention are achieved, within the range that does not inhibit the effects of the present invention, for example, due to inevitable circumstances during the process of manufacturing the glaze layer 20, etc., the present invention does not exclude the mode where the region where the antiviral agent undergoes binodal phase separation exists at a lower ratio compared to the region where the antiviral agent undergoes spinodal phase separation.

[0045] In addition, since the antiviral agent exists in the spinodal phase separation state on the surface of the glaze layer 20, it exhibits white due to scattering by the interface between the two phases, and it becomes possible to realize a glaze layer surface with excellent mapping properties described later.

[0046] In the present invention, the elution amount of the specific lanthanoid ions on the surface of the glaze layer 20 for exhibiting practical virus activity is preferably at least as shown below. Lanthanum (La): about 0.05 ppm Praseodymium (Pr): about 0.052 ppm Neodymium (Nd): about 0.052 ppm Samarium (Sm): about 0.054 ppm Gadolinium (Gd): about 0.056 ppm Terbium (Tb): about 0.057 ppm Dysprosium (Dy): about 0.057 ppm Holmium (Ho): about 0.058 ppm Erbium (Er): about 0.059 ppm Thulium (Tm): about 0.059 ppm Ytterbium (Yb): about 0.060 ppm Lutetium (Lu): about 0.061 ppm Further, in a preferred embodiment of the present invention, the elution amount of the specific lanthanoid is about 1 to 2% of the content of the specific lanthanoid contained in the region having a depth of 10 nm in the direction from the surface of the glaze layer toward the pottery body (the direction of the arrow shown in FIG. 1).

[0047] Surface properties Average roughness (Ra) The glaze layer 20 has a surface roughness (Ra) of less than 0.07 μm. Since the surface roughness (Ra) is less than 0.07 μm, it becomes difficult for urinary calculi, mold, stains, and other dirt to adhere to the sanitary pottery, and even if they adhere, they can be easily removed by a weak water flow. As a result, the surface of the sanitary pottery can be maintained in a clean state for a long time without requiring 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. In this case, the difficulty of dirt adhesion and easy removability are further improved.

[0049] In the present invention, the "surface roughness (Ra)" refers to the center line average roughness (μm) measured by a stylus type surface roughness measuring device (JIS-B0651) and defined by JIS-B0601 (1994).

[0050] DOI value The glaze layer 20 preferably has a DOI value of 80 or more as measured by a wave scan DOI measuring device on its surface. In the present invention, the "DOI value" refers to the DOI value measured by a wave scan DOI measuring device, for example, Wave-ScanDIO (orange peel measuring device) manufactured by BYK Gardner (Germany). In the present invention, the DOI value is used as an index representing the surface mapping property of the glaze layer provided on the sanitary ware according to the present invention. The "mapping property" refers to the sharpness of the reflection of an object, and this appearance quality is determined by the difference in light reflection due to the surface shape of the glaze layer and is recognized by human vision.

[0051] When the DOI value on the surface of the glaze layer 20 is 80 or more, it gives an impression of excellent mapping property, and as a result, the sanitary ware has a high-class feeling. In addition, good mapping property makes the dirt attached to the sanitary ware more conspicuous and enables early detection of the attachment of dirt such as virus-containing contaminants, so that the attachment of contaminants can be suppressed from being left unattended. According to a preferred embodiment of the present invention, the DOI value on the surface of the glaze layer 20 is 85 or more.

[0052] The above wave scan DOI measuring device scans by moving a laser point light source on the surface of the glaze layer, and like the human eye, measures the light and dark of the reflected light one by one at determined intervals, detects the optical profile of the surface of the glaze layer, and further analyzes the structure of the surface of the glaze layer by performing spectral analysis of this optical profile through a frequency filter. The microwave scan by the above device irradiates laser light at an angle of 60° inclined from the perpendicular line to the surface of the glaze layer with a laser point light source, and the detector measures the reflected light at the same angle opposite to the perpendicular line. The characteristic spectrum of the above device is as follows. du: Wavelength 0.1 mm or less Wa: Wavelength 0.1 - 0.3 mm Wb: Wavelength 0.3 - 1 mm Wc: Wavelength 1 - 3 mm Wd: Wavelength 3 - 10 mm We: Wavelength 10 - 30 mm Sw: Wavelength 0.3 - 1.2 mm Lw: Wavelength 1.2 to 12 mm DOI: Wavelength below 0.3 mm 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. By having the ΔE* value of the surface of the glaze layer 20 be 1.20 or less, a sanitary ceramic ware with excellent light resistance can be obtained. The ΔE* value is determined in accordance with the sunshine carbon arc lamp method described in Section 8, Chapter 9 of JIS K5400 (1990), using a sunshine carbon arc lamp weather resistance tester (manufactured by Suga Test Instruments Co., Ltd., S-300) to conduct a weather resistance test. The test time is 8 hours, and the L*, a*, and b* values of the photocatalyst coating before and after the test are measured by the SCE method, and the color difference: ΔE* = [(ΔL*) 2 +(Δa*) 2 +(Δb*) 2 1 / 2 is calculated. As the color difference meter, a color and color difference meter (manufactured by Konica Minolta, CR-400) can be used. 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 μm to 400 μm. With the glaze layer 20 having such a thickness, the above-described surface properties can be realized.

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

[0056] ​First, prepare a pottery body 10. The pottery body 10 may be appropriately formed from a conventionally known sanitary pottery body slurry prepared using silica sand, pottery stone, clay, etc. as raw materials.

[0057] Prepare a glaze slurry for forming the glaze layer 20, that is, a glaze slurry containing an antiviral agent and other glaze materials. The composition of the glaze materials other than the antiviral agent is, for example, as described in Table 1 above. Also, the antiviral agent contained in the glaze slurry is preferably a specific lanthanoid compound as a starting material for the specific lanthanoid that is usually contained in the glaze layer 20. As such a specific lanthanoid compound, for example, those having a boiling point of 1000 °C or higher, more preferably those having a boiling point of 1300 °C or higher, and those having a melting point of 1000 °C or higher, such as oxides of specific lanthanoids, can be used. Even more preferably, it is a compound having a melting point of 1000 °C or higher and being water-insoluble.

[0058] The glaze slurry for forming the glaze layer 20 can be prepared, for example, as follows. Embodiment 1 Put the glaze materials having the composition described in Table 1, water, and a dispersion medium (e.g., alumina balls) into a pottery pot and grind them, for example, by a ball mill to obtain a glaze slurry precursor. Add an antiviral agent compound to this glaze slurry precursor, mix and grind to obtain a glaze slurry for forming the glaze layer 20. Embodiment 2 Melt the glaze materials having the composition described in Table 1 at a predetermined temperature, cool to obtain a frit raw material. Add an antiviral agent compound to this frit raw material, further add water, a dispersion medium, and, if necessary, other raw materials (e.g., pottery stone, ZnO, etc.), put them into a pottery pot, and grind them, for example, by a ball mill to obtain a glaze slurry for forming the glaze layer 20.

[0059] According to a preferred embodiment of the present invention, in the above-described Embodiments 1 and 2, it is preferable that the average particle size of the antiviral agent after pulverization and the average particle size of the glaze material after pulverization are substantially the same. For example, the average particle sizes of the antiviral agent and the glaze material are preferably 10 μm or less, preferably about 6 to 7 μm and substantially the same. Here, the average particle size means the so-called 50% particle size in the particle size distribution data measured by the laser diffraction method. Further, "substantially the same" average particle size means that the ratio (the former / the latter) of the average particle size of the antiviral agent to the average particle size of the glaze material is within the range of 0.9 to 1.1.

[0060] By making the average particle sizes of the antiviral agent and the glaze material coincide in this way, the antiviral agent (specific lanthanoid) can be spinodal phase-separated on the surface of the glaze layer 20, and the above-described surface properties (Ra, DOI value, ΔE* value) can be realized.

[0061] Next, the glaze slurry for forming the glaze layer 20 is applied to the surface of the pottery body 10. The application method is not particularly limited, and general methods such as spray coating and dip coating can be appropriately selected and used.

[0062] Next, the pottery body 10 to which the glaze slurry for forming the glaze layer 20 has been applied is fired. That is, the pottery body 10 and the glaze slurry are integrally fired. The firing temperature is preferably a temperature at which the sanitary pottery body is sintered and the glaze is softened, and further 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. It is preferable to perform the integral firing only once. The inventors have confirmed by experiments that the crystallization of the antiviral agent is suppressed by performing the integral firing only once. Specifically, it has been confirmed that crystals precipitate from the amorphous layer of the glaze layer when firing is performed a plurality of times, and crystals precipitate when the second firing is performed at a temperature lower than the first firing temperature.

[0063] Next, the obtained fired body is cooled. The cooling conditions are not particularly limited, and natural cooling may be used, or the temperature and time may be appropriately controlled.

[0064] The pottery base 10 and the glaze slurry prepared such that the average particle size of the antiviral agent and the average particle size of the other glaze materials are substantially the same are integrally fired once at a temperature lower than the melting point of the antiviral agent and then cooled, thereby suppressing the crystallization of the antiviral agent, preferably vitrifying it, more preferably forming a glass liquid phase (glass melt), even more preferably phase-separating the glass melt, and most preferably spinodal phase-separating it. As a result, a glaze layer 20 can be obtained in which regions where the antiviral agent is spinodally phase-separated are rich on its surface.

Examples

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

[0066] Production of the body of pottery Using a pottery base mud slurry prepared from raw materials such as silica sand, feldspar, and clay, a 70 mm × 150 mm plate-shaped test piece was produced.

[0067] Preparation of the glaze slurry for forming the base glaze layer 2 kg of a 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 pottery pot, and pulverization was performed using a ball mill so that the particle size measurement result of the glaze slurry after pulverization using a laser diffraction particle size distribution analyzer was such that 65% was 10 μm or less and the 50% particle size was about 6.5 μm, to obtain a glaze slurry for forming a base glaze layer.

[0068]

Table 2

[0069] Preparation of the glaze slurry for forming the antiviral glaze layer 2 kg of glaze material composed of the composition described in Table 3 below, 1 kg of water, and 4 kg of alumina balls were placed in a 6 L pottery pot. The particle size measurement results of the glaze slurry after grinding using a laser diffraction particle size distribution analyzer were such that 65% was 10 μm or less and the 50% particle size (D50) was 6.5 μm. Grinding was performed using a ball mill to obtain a glaze slurry precursor. 5% by weight of the oxide of the lanthanoid described in Table 4 was added to this glaze slurry precursor (that is, 5% by weight of the lanthanoid oxide was added based on the total content of 100% by weight of the above glaze material), mixed, and grinding was performed using a ball mill so that 65% was 10 μm or less and the 50% particle size (D50) was 6.5 μm. After grinding, antiviral glaze slurries for sanitary ceramics of Examples 1 to 9 and Comparative Example 1 were prepared.

[0070]

Table 3

[0071] Production of sanitary ware Each of the antiviral glaze slurries prepared as described above was applied to the above pottery substrate test piece by the spray coating method. Thereafter, it was integrally fired once at 1200 °C in a kettle, cooled, and sanitary ceramics of Examples 1 to 9 and Comparative Example 1 were produced.

[0072] Evaluation The following evaluations were performed on the sanitary ceramics of Examples 1 to 9 and Comparative Example 1.

[0073] Content of the antiviral agent The specific lanthanoid content based on the equivalent amount of the specific lanthanoid oxide contained in the glaze layer of the sanitary ceramics of Examples 1 to 9 and Comparative Example 1, for example, for the sanitary ceramics of Example 1, is calculated as the percentage of lanthanum oxide (5% by weight) with respect to the total of 100% by weight of the glaze material shown in Table 1 and 5% by weight of lanthanum oxide, 5% by weight / (100% by weight + 5% by weight) × 100 ≈ 4.8%. The same applies to Examples 2 to 9 and Comparative Example 1.

[0074] Antiviral property 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 solution was dropped onto the sanitary wares of Examples 1 to 9 and Comparative Example 1, and the sanitary ware without an antiviral agent in the glaze layer as a control, and then covered with a film. · Each sanitary ware was allowed to stand at 25 °C for 24 hours. · After standing, the virus on each sanitary ware was washed out and collected, and then the virus infection titer was measured. · The antiviral activity value was calculated by the following formula. R = Ut - At R: Antiviral activity value Ut: Common logarithm of the virus infection titer (PFU / cm 2 ) after 24 hours of standing of the sanitary ware of the control At: Common logarithm of the virus infection titer (PFU / cm 2 ) after 24 hours of standing of the sanitary wares of Examples 1 to 9 and Comparative Example 1 The antiviral activity values of the sanitary wares of Examples 1 to 9 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.

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

[0076] Confirmation of the existence state in the vicinity of the surface of the glaze layer of a specific lanthanoid <XRD measurement> XRD device: Using <X’Pert PRO> manufactured by PANalytical, the measurement was carried out under the following conditions. XRD measurement conditions Measurement range: 3° to 60° Scanning rate: 4° / min Applied voltage: 45 V, Applied current: 40 mA As shown in Fig. 2, no peaks were observed in the XRD measurement of the surface of the antiviral glaze layer containing a specific lanthanoid. Therefore, it was confirmed that the specific lanthanoid exists in an amorphous or vitrified state on the surface of the antiviral glaze layer.

[0077] <SEM Observation> The existence state of the specific lanthanoid near the surface of the antiviral glaze layer was observed by SEM. The SEM observation was carried out using a device: S4800 (manufactured by Hitachi High-Technologies), conditions: magnification 50,000 times, applied voltage 2.0 kV, applied current 20 mA (2.0 mm × 50.0 k SE (U, LA100)). The SEM images are shown in Figs. 3 to 11. Each Fig. A is the surface SEM image of the antiviral glaze layer, and each Fig. B is the cross-sectional SEM image of the antiviral glaze layer. In both Figs. A and B, the white part indicates the presence of the specific lanthanoid, and the black part indicates the Si-O structure. In Fig. B, the part that looks like a boundary line shows that the white part indicates the state where the specific lanthanoid is rich. Since the image area above the white part is the air area, it is out of the observation target. From each figure, it was confirmed that the specific lanthanoid exists richly in the glaze layer, especially near the surface of the glaze layer, that the specific lanthanoid undergoes spinodal phase separation, and that the spinodal dispersion region of the specific lanthanoid is rich near the surface of the glaze layer.

[0078]

Table 4

[0079] Confirmation of the existence (distribution) state of the antiviral agent in the glaze layer of the antiviral agent based on the content of the antiviral agent In the sanitary ware of Example 1 described above, sanitary wares of Examples 1 to 15 in which the content of lanthanum was changed to various amounts were produced in the same manner as the production method of Example 1. The amount (weight %) of lanthanum oxide (La2O3) equivalent and the atomic abundance (mass %) measured by XRF of lanthanum contained in the glaze layer of the sanitary wares of Examples 1 to 15 were as shown in Table 5, respectively. The lanthanum content (weight %) based on the amount of lanthanum oxide (La2O3) equivalent of each sanitary ware shown in Table 5, for example, for the sanitary ware of Example 4, was calculated as the percentage of lanthanum oxide (5 wt%) with respect to the total of 100 wt% of the glaze material and 5 wt% of lanthanum oxide shown in Table 1, i.e., 5 wt% / (100 wt% + 5 wt%) × 100 ≒ 4.8%. The same applies to the other Examples 1 to 3 and 4 to 15. The sanitary ware of Example 4 is the same as the sanitary ware of Example 1. When comparing the lanthanum content (weight %) based on the amount of lanthanum oxide (La2O3) equivalent of each 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 contained in the whole antiviral glaze layer. That is, it indicates that lanthanum is concentrated near the surface of the antiviral glaze layer. Therefore, according to the present invention, an antiviral agent (specific lanthanoid) can be concentrated and present near the surface of the glaze layer, and as a result, good antiviral properties can be exhibited. Further, according to the present invention, even a small amount of the antiviral agent can be concentrated near the surface of the glaze layer, so that good antiviral properties can be efficiently exhibited, and since the amount of the antiviral agent is small, it does not affect the Si-O structure of the glaze layer, that is, it is possible to realize a sanitary pottery with excellent surface properties maintained.

[0080] Light resistance (discoloration suppression ability) In addition, the light resistance (discoloration suppression ability) of the sanitary potteries of Examples 1 to 15 was evaluated. Specifically, in accordance with JIS K5400-9-8 Sunshine Carbon Arc Method, a weather resistance test was carried out using a Sunshine Carbon Arc Lamp Type Weather Resistance Tester (manufactured by Atlas Corporation, USA). The test time was 8 hours, and the L*, a*, b* values of the photocatalytic coating body before and after the test were measured by the SCE method, and the color difference: ΔE* = [(ΔL*) 2 +(Δa*) 2 +(Δb*) 2 1 / 2 was determined. As the color difference meter, a Color Difference Meter (manufactured by Konica Minolta, CR-400) was used. The results were as shown in Table 5.

[0081]

Table 5

[0082] Relationship between the content of the antiviral agent, the elution amount of the antiviral agent, and the antiviral activity value In addition, the relationship between the content of the antiviral agent, the elution amount of the antiviral agent, and the antiviral activity value in the sanitary potteries of Examples 1 to 15 was confirmed. ​Figure 12A shows the relationship between the amount of lanthanum in terms of lanthanum oxide (La2O3) conversion (wt%) and the elution amount of lanthanum on the surface of the glaze layer (ppm). Figure 12B shows the relationship between the elution amount of lanthanum and the antiviral activity value. Figure 13A shows the relationship between the amount of lanthanum in terms of lanthanum oxide (La2O3) conversion (wt%) and the atomic abundance (mass%) measured by XRF. Figure 13B shows the relationship between the atomic abundance (mass%) of lanthanum measured by XRF and the antiviral activity value. From Figures 12 and 13, it was confirmed that a proportional relationship holds between the amount of lanthanum in terms of lanthanum oxide (La2O3) conversion (wt%) and the atomic abundance (mass%) of lanthanum measured by XRF, a proportional relationship holds between the content of lanthanum and the elution amount of lanthanum on the surface of the glaze layer, and a proportional relationship also holds between the elution amount of lanthanum and the antiviral activity value.

[0083] Confirmation of the relationship between the firing conditions, the spinodal phase separation amount, and the antiviral activity value The addition amount of lanthanum oxide was set to 10 wt%, and the antiviral glaze slurry prepared according to the above preparation example was applied to the above pottery substrate test piece by spray coating method. Then, it was fired in a kettle under the following conditions 1 to 3 to produce three types of sanitary pottery A to C. Sanitary pottery A: Firing condition 1 (firing temperature: 1200 °C, total firing time: 10 hours) Sanitary pottery B: Firing condition 2 (firing temperature: 1200 °C, total firing time: 15 hours) Sanitary pottery C: Firing condition 3 (firing temperature: 1200 °C, total firing time: 20 hours) The antiviral activity values of sanitary pottery A to C were as shown in Table 6 below. Also, the existence state of lanthanum near the surface of the antiviral glaze layer of sanitary pottery A to C was as shown in Figures 14A to C.

[0084]

Table 6

Explanation of Signs

[0085] 1 Sanitary ware, 10 Ceramic body, 20 (Top) Glaze layer, 30 Base glaze layer

Claims

1. A sanitary pottery comprising a pottery body and a glaze layer formed on the surface of the pottery body, wherein the glaze layer contains a lanthanoid as an antiviral agent, the surface roughness (Ra) of the glaze layer is 0.07 μm or less, the lanthanoid is at least one selected from the group consisting of 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), the content of lanthanum (La) (in terms of oxide) is 5% by weight or more and less than 10% by weight, the content of praseodymium (Pr) (in terms of oxide) is 1.0% by weight or more and 20.0% by weight or less, the content of neodymium (Nd) (in terms of oxide) is 1.0% by weight or more and 20.0% by weight or less, the content of samarium (Sm) (in terms of oxide) is 1.1% by weight or more and 22.0% by weight or less, the content of gadolinium (Gd) (in terms of oxide) is 1.1% by weight or more and 22.0% by weight or less, the content of terbium (Tb) (in terms of oxide) is 1.1% by weight or more and 22.0% by weight or less, the content of dysprosium (Dy) (in terms of oxide) is 1.1% by weight or more and 22.0% by weight or less, the content of holmium (Ho) (in terms of oxide) is 1.2% by weight or more and 24.0% by weight or less, the content of erbium (Er) (in terms of oxide) is 1.2% by weight or more and 24.0% by weight or less, the content of thulium (Tm) (in terms of oxide) is 1.2% by weight or more and 24.0% by weight or less, the content of ytterbium (Yb) (in terms of oxide) is 1.2% by weight or more and 24.0% by weight or less, the content of lutetium (Lu) (in terms of oxide) is 1.2% by weight or more and 24.0% by weight or less, The sanitary pottery is characterized in that the antiviral agent exists in an amorphous state on at least the surface of the glaze layer.

2. The sanitary pottery according to claim 1, wherein the DOI value of the glaze layer measured by a wave scan DOI measuring device on its surface is 80 or more.

3. The sanitary pottery according to claim 1 or 2, wherein the antiviral agent is spinodally phase-separated on at least the surface of the glaze layer.

4. The sanitary pottery according to any one of claims 1 to 3, further comprising a base glaze layer between the pottery body and the glaze layer.

5. A method for manufacturing the sanitary pottery according to any one of claims 1 to 4, comprising: a step of preparing a pottery body; a step of preparing a glaze slurry containing a lanthanoid or a lanthanoid compound as an antiviral agent and a glaze material other than the antiviral agent; a step of applying the glaze slurry to the surface of the pottery body; a step of firing the pottery body to which the glaze slurry has been applied to form a glaze layer and characterized by at least including.

6. The method according to claim 5, wherein the ratio (the former / the latter) of the average particle size of the antiviral agent to the average particle size of the glaze material is in the range of 0.9 to 1.

1.

7. The method according to claim 5 or 6, further comprising a step of forming a base glaze layer on the surface of the pottery body, and applying the glaze slurry to the surface of the base glaze layer.

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