JP7697268B2 - Sanitary ware - Google Patents

Description

The present invention relates to sanitary ware, and more specifically to sanitary ware that combines antiviral properties with low adhesion and easy removal of dirt.

In order to ensure a hygienic surface and to ensure the appearance design of sanitary ware, a glaze layer is formed on the outermost surface. To improve hygiene, a technology has been proposed in which an antibacterial agent is added to the glaze layer. For example, CN111393188A (Patent Document 1) discloses a sanitary ware that includes a base glaze layer and a top glaze layer that contains a nano-silver antibacterial agent.

In addition, examples of imparting antiviral properties to composite oxides have been reported. WO2020/017493A1 (Patent Document 2) suggests that composite oxide ceramics containing rare earth elements and other specific metal elements have both water repellency and antibacterial and antiviral properties. Specifically, it discloses that calcined powder (500°C) of composite oxide ceramics (LMO) containing lanthanum (La) and molybdenum (Mo) exhibits higher activity against bacteriophages Qβ and Φ6 than single oxides (La ₂ O ₃ particles) (paragraphs 0067, 0069-0071, FIG. 8).

In Patent Document 2, although no comparison with single oxides is confirmed, it is disclosed that calcined powder (500°C, 400°C, or 550°C) of composite oxide ceramics (LMO, LWO, LCMO (LMO with part of the La replaced with cerium (Ce)), LMWO (LMO with part of the Mo replaced with W)) containing lanthanum (La) and/or tungsten (W) shows activity against bacteriophages Qβ and Φ6 (Figures 11, 14-17, 20).

In addition, Cosmetology Research Report Vol. 28, 2020, pp. 43-52 (Non-Patent Document 1), written by the inventor of Patent Document 2, discloses the same content as Patent Document 2, and discloses that CeO ₂ shows almost no activity against bacteriophages Qβ and Φ6, whereas La ₂ O ₃ shows a certain level of activity, and that the anti-Qβ and Φ6 activities of La ₂ O ₃ are lower than those of LMO (page 47, second paragraph in the right column, FIG. 7).

On the other hand, there have been reports of liquid compositions that have been given antiviral properties. JP 2020-111546 A (Patent Document 3) proposes an antiviral composition containing a rare earth salt, a zinc salt, and water, and specifically discloses 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., a higher antiviral property, than an aqueous solution lacking either a rare earth salt or a zinc salt. Patent Document 3 discloses that the antiviral composition is processed into fibers and also suggests that it is processed into a coating agent such as a paint, but does not disclose that it is processed into a ceramic material or a glaze material.

To date, there have been no reports that rare earth elements such as La, particularly lanthanides, have practical antiviral properties on their own, while the recent COVID-19 pandemic has led to an increased need for sanitary ware with practical antiviral properties. Furthermore, adding additives to glazes generally roughens the surface of the sanitary ware, which can be undesirable from the standpoint of stain resistance or design.

CN111393188A publication WO2020/017493A1 publication JP 2020-111546 A

Cosmetology Research Report Vol. 28, 2020, p43-52

The present inventors have now experimentally confirmed that lanthanoids, preferably lanthanoids present in a specific state in the glaze layer, as components of the glaze layer of sanitary ware, exert practical antiviral properties on their own, and further confirmed that a glaze layer containing such lanthanoids or lanthanoid compounds not only exerts good antiviral properties, but also maintains excellent surface properties in terms of resistance to adhesion of dirt and ease of removal (properties that make dirt less likely to adhere and easier to remove) in the presence of other components. The present invention is based on such findings.

Therefore, the present invention aims to provide sanitary ware equipped with a glaze layer that has practical antiviral properties and is stain-resistant and easy to remove.

The sanitary ware according to the present invention has:
The present invention comprises a pottery base and a glaze layer formed on a surface of the pottery base,
The glaze layer contains a lanthanoid as an antiviral agent,
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), excluding cerium (Ce), europium, and promethium (Pm).

The present invention provides sanitary ware equipped with a glaze layer that combines practical antiviral properties with stain-resistant and easy-to-remove stain properties.

FIG. 1 is a schematic diagram of a sanitary ware according to the present invention. FIG. 1 is a schematic diagram of a sanitary ware according to one embodiment of the present invention. 1 shows an XRD pattern of the glaze layer of the sanitary ware according to the present invention. 1 is a SEM image of the surface of a glaze layer of a sanitary ware according to the present invention, showing the state in which lanthanum (La) is present in a spinodal phase separation state on the surface of the glaze layer. 1 is a cross-sectional SEM image of a glaze layer of a sanitary ware according to the present invention, showing the presence of lanthanum (La) in a spinodal phase separation state near the surface of the glaze layer. 1 is a SEM image of the surface of a glaze layer of a sanitary ware according to the present invention, showing neodymium (Nd) present in a spinodal phase separation state on the surface of the glaze layer. 1 is a cross-sectional SEM image of a glaze layer of a sanitary ware according to the present invention, showing neodymium (Nd) present in a spinodal phase separation state near the surface of the glaze layer. 1 is a SEM image of the surface of a glaze layer of a sanitary ware according to the present invention, showing the state in which praseodymium (Pr) is present in a spinodal phase separation state on the surface of the glaze layer. 1 is a cross-sectional SEM image of a glaze layer of a sanitary ware according to the present invention, showing the state in which praseodymium (Pr) is present in a spinodal phase separation state near the surface of the glaze layer. 1 is a SEM image of the surface of a glaze layer of a sanitary ware according to the present invention, showing the state in which samarium (Sm) is present in a spinodal phase separation state on the surface of the glaze layer. 1 is a cross-sectional SEM image of a glaze layer of a sanitary ware according to the present invention, showing the state in which samarium (Sm) is present in a spinodal phase separation state near the surface of the glaze layer. 1 is a SEM image of the surface of a glaze layer of a sanitary ware according to the present invention, showing gadolinium (Gd) present in a spinodal phase separation state on the surface of the glaze layer. 1 is a cross-sectional SEM image of a glaze layer of a sanitary ware according to the present invention, showing gadolinium (Gd) present in a spinodal phase separation state near the surface of the glaze layer. 1 is a SEM image of the surface of a glaze layer of a sanitary ware according to the present invention, showing the state in which dysprosium (Dy) is present in a spinodal phase separation state on the surface of the glaze layer. 1 is a cross-sectional SEM image of a glaze layer of a sanitary ware according to the present invention, showing the presence of dysprosium (Dy) in a spinodal phase separation state near the surface of the glaze layer. 1 is a SEM image of the surface of a glaze layer of a sanitary ware according to the present invention, showing the state in which holmium (Ho) is present in a spinodal phase separation state on the surface of the glaze layer. 1 is a cross-sectional SEM image of a glaze layer of a sanitary ware according to the present invention, showing the presence of holmium (Ho) in a spinodal phase separation state near the surface of the glaze layer. 1 is a SEM image of the surface of a glaze layer of a sanitary ware according to the present invention, showing the state in which erbium (Er) is present in a spinodal phase separation state on the surface of the glaze layer. 1 is a cross-sectional SEM image of a glaze layer of a sanitary ware according to the present invention, showing the state in which erbium (Er) is present in a spinodal phase separation state near the surface of the glaze layer. 1 is a SEM image of the surface of a glaze layer of a sanitary ware according to the present invention, showing the state in which ytterbium (Yb) is present in a spinodal phase separation state on the surface of the glaze layer. 1 is a cross-sectional SEM image of a glaze layer of a sanitary ware according to the present invention, showing the state in which ytterbium (Yb) is present in a spinodal phase separation state near the surface of the glaze layer. The relationship between the amount of lanthanum converted into lanthanum oxide and the amount of lanthanum dissolved onto the surface of the glaze layer is shown. The relationship between the amount of lanthanum eluted and the antiviral activity value is shown. 1 shows the relationship between the amount of lanthanum converted to lanthanum oxide (wt %) and the atomic abundance (mass %) of lanthanum measured by XRF. 1 shows the relationship between the atomic abundance (mass%) of lanthanum measured by XRF and the antiviral activity value. FIG. 1 is an SEM cross-sectional image showing the state of lanthanum in a glaze layer when a glaze containing 10% by weight of lanthanum oxide as a raw material for an antiviral agent was fired under firing condition 1 (1200° C. for a short time). FIG. 13 is an SEM cross-sectional image showing the state of lanthanum in a glaze layer when a glaze containing 10% by weight of lanthanum oxide as a raw material for an antiviral agent was fired under firing condition 2 (1200° C. for medium time). FIG. 13 is an SEM cross-sectional image showing the state of lanthanum in a glaze layer when a glaze containing 10% by weight of lanthanum oxide as a raw material for an antiviral agent was fired under firing condition 3 (1200° C. for a long time).

Definition In this invention, "sanitary ware" refers to ceramic products used around toilets and washrooms, specifically toilet bowls, urinals, toilet strainers, toilet tanks, washstand basins, hand basins, etc. Additionally, "pottery" refers to ceramics whose base is fired to a degree that it is slightly absorbent and whose surface is glazed.

In addition, in the present invention, a lanthanoid or a lanthanoid compound "alone" exhibits practical antiviral properties, meaning that the lanthanoid or the lanthanoid compound itself exhibits practical antiviral properties, whereas the composite oxide disclosed in Patent Document 2 exhibits antiviral properties by being composed of lanthanum and other metal elements (Mo, W), and the liquid composition disclosed in Patent Document 3 exhibits antiviral properties by containing a rare earth salt and other metal salt (zinc salt).

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

The sanitary ware 1 according to the present invention may further comprise one or more additional glaze layers between the ceramic base 10 and the glaze layer 20 containing the antiviral agent. For example, according to one embodiment of the present invention, as shown in FIG. 1B, the sanitary ware 1 comprises a ceramic base 10, a glaze layer 30 formed on the surface of the ceramic base 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 is sometimes referred to as a base glaze layer, and the 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 normally applied to a ceramic base.

The pottery body 10 is not particularly limited and may be a conventionally known pottery body. That is, it may be a sanitary ware body slip prepared from raw materials such as silica sand, feldspar, clay, etc., which is appropriately shaped.

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

Antiviral Agent In the present invention, the antiviral agent is at least one lanthanoid selected from the group consisting of 12 elements: lanthanum (La), praseodymium (Pr), neodymium (Nd), samarium (Sm), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu). In other words, the antiviral agent is a lanthanoid excluding cerium (Ce), europium (Eu), and promethium (Pm) (hereinafter, the above 12 lanthanoids excluding Ce, Eu, and Pm may be referred to as "specific lanthanoids"). According to a preferred embodiment of the present invention, the specific lanthanoid is at least one selected from the group consisting of La, Gd, Dy, and Yb.

In the present invention, the reason why Ce and Eu are excluded from the lanthanoids is that only these two atoms among the lanthanoids have two stable valences. That is, the Ce atom stably has two types of valences, +3 and +4, and the Eu atom stably has two types of valences, +2 and +3, and thus affects the Si-O bond of the glaze layer 20 by donating electrons to the Si-O bond, such as by extending the Si-O bond, that is, by affecting the vitrified structure of the glaze layer 20, resulting in a rough surface of the glaze layer 20. For this reason, the surface properties described below cannot be realized, and the glaze layer 20 is inappropriate as a component to be contained therein. In other words, when imparting antiviral properties to the glaze layer of sanitary ware, it is preferable to use an antiviral agent that has little effect on the Si-O bond.
In the present invention, the reason for excluding Pm from the lanthanoids is that, among the lanthanoids, this atom does not exist stably, is radioactive, and has physical properties significantly different from those of other lanthanoids.

The specific lanthanoid 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, the specific lanthanoid that dissolves on the surface of the glaze layer and ionizes in a chemically stable state inactivates viruses attached to the surface of the glaze layer. In this way, the glaze layer 20 is able to exhibit good antiviral properties.

In the present invention, the antiviral properties of sanitary ware having a glaze layer 20 containing a specific lanthanoid can be expressed as an index of antiviral activity value against bacteriophage Qβ. The antiviral activity value can be determined, for example, by the following test method in accordance with ISO 21702.

<Antiviral test method>
0.4 mL of the virus liquid is dropped onto the test pieces (a sanitary ware test piece with a glaze layer containing a specific lanthanide, and a control (a sanitary ware test piece with a glaze layer not containing an antiviral agent)), and the pieces are covered with a film.
- Leave the test piece at rest 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: common logarithm of the viral infectivity (PFU/cm ² ) of the control after standing for 24 hours At: common logarithm of the viral infectivity (PFU/cm ² ) of a test piece of sanitary ware having a glaze layer containing a specific lanthanoid after standing for 24 hours

In the present invention, the antiviral activity of the sanitary ware having the glaze layer 20 containing a specific lanthanoid can be expressed as an index of the antiviral activity value (V) obtained according to JIS R1756 visible light B condition in bright place. Specifically, an antiviral test is performed using bacteriophage Qβ according to JIS R1756 visible light B condition. Using a 20W white fluorescent lamp (Toshiba Lighting & Technology Corporation, "Neoline" FL20S/W) as the light source, visible light of 380 nm or more is irradiated at an illuminance of 500 lux through an ultraviolet cut filter (Nitto Plastics Industry Co., Ltd., N-169). The illuminance is measured using an illuminometer: IM-5 manufactured by Topcon Corporation. The antiviral activity value (V) in bright place can be calculated by the following formula, assuming that the visible light irradiation time is 4 hours.

Antiviral activity value: V = Log ₁₀ (UV/TV)
TV: Bacteriophage infectivity titer (pfu) of sanitary ware having a glaze layer containing a specific lanthanoid after light irradiation
UV: Bacteriophage infectivity (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.

In the present invention, the glaze layer 20 containing a specific lanthanoid 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.

In a preferred embodiment of the present invention, the content of the antiviral agent (specific lanthanoid) contained in the glaze layer 20 is, when the total of the antiviral agent constituting the glaze layer and the other glaze materials described below is taken as 100% by weight, 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, in terms of specific lanthanoid oxide. It goes without saying that the amount of specific lanthanoid oxide can be stoichiometrically converted to the weight % of the specific lanthanoid.

Moreover, the preferred contents (in terms of oxide) of the antiviral agent contained in the glaze layer 20 for each specific lanthanoid are as follows:
Lanthanum (La): 1.0 wt.% to 20.0 wt.%, with the upper limit preferably being about 14 wt.%, more preferably 11 to 12 wt.%, even more preferably about 9 wt.%, and the lower limit preferably being 5 wt.% or more.
Praseodymium (Pr): 1.0 wt.% to 20.0 wt.%, with the upper limit preferably being about 14 wt.%, more preferably 11-12 wt.%, even more preferably about 9 wt.%, and the lower limit preferably being 5 wt.% or more.
Neodymium (Nd): 1.0 wt.% to 20.0 wt.%, with the upper limit preferably being about 14 wt.%, more preferably 11 to 12 wt.%, even more preferably about 9 wt.%, and the lower limit preferably being 5 wt.% or more.
Samarium (Sm): 1.1 wt.% to 22.0 wt.%, with the upper limit preferably being about 15.4 wt.%, more preferably 12.1 to 13.2 wt.%, even more preferably about 9.9 wt.%, and the lower limit preferably being 5.5 wt.% or more.
Gadolinium (Gd): 1.1% to 22.0% by weight, with the upper limit preferably being about 15.4% by weight, more preferably 12.1 to 13.2% by weight, even more preferably about 9.9% by weight, and the lower limit preferably being 5.5% by weight or greater.
Terbium (Tb): 1.1 wt. % to 22.0 wt. %, with the upper limit preferably being about 15.4 wt. %, more preferably being 12.1 to 13.2 wt. %, even more preferably being about 9.9 wt. %, and the lower limit preferably being 5.5 wt. % or more.
Dysprosium (Dy): 1.1 wt.% to 22.0 wt.%, with the upper limit preferably being about 15.4 wt.%, more preferably being 12.1 to 13.2 wt.%, even more preferably being about 9.9 wt.%, and the lower limit preferably being 5.5 wt.% or more.
Holmium (Ho): 1.2 wt.% to 24.0 wt.%, with the upper limit preferably being about 16.8 wt.%, more preferably 13.2 to 14.4 wt.%, even more preferably about 10.8 wt.%, and the lower limit preferably being 6 wt.% or more.
Erbium (Er): 1.2 wt % to 24.0 wt %, with the upper limit preferably being about 16.8 wt %, more preferably 13.2 to 14.4 wt %, even more preferably about 10.8 wt %, and the lower limit preferably being 6 wt % or greater.
Thulium (Tm): 1.2 wt.% to 24.0 wt.%, with the upper limit preferably being about 16.8 wt.%, more preferably 13.2 to 14.4 wt.%, even more preferably about 10.8 wt.%, and the lower limit preferably being 6 wt.% or more.
Ytterbium (Yb): 1.2 wt. % to 24.0 wt. %, with the upper limit preferably being about 16.8 wt. %, more preferably being 13.2 to 14.4 wt. %, even more preferably being about 10.8 wt. %, and the lower limit preferably being 6 wt. % or more.
Lutetium (Lu): 1.2 wt.% to 24.0 wt.%, with the upper limit preferably being about 16.8 wt.%, more preferably 13.2 to 14.4 wt.%, even more preferably about 10.8 wt.%, and the lower limit preferably being 6 wt.% or more.

By including the specific lanthanoid in the amount within the range described above, the glaze layer 20 can exhibit even better antiviral properties.

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 spectrometry (XRF). In the present invention, the atomic abundance (mass%) of the specific lanthanoid contained in the glaze layer 20 can be determined using a scanning X-ray fluorescence analyzer (Rigaku ZSX Primus IV (manufactured by Rigaku Corporation)) under the following measurement and analysis conditions.
(Measurement conditions)
Tube voltage: 60 kV
Tube current: 50mA
Measurement depth: Several tens of μm (about 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-mentioned scanning X-ray fluorescence analyzer has a measurement limit of a region from the outermost surface (0 μm) of the glaze layer 20 to a depth of approximately 50 μm in the direction of the ceramic body (the direction of the arrow shown in FIG. 1 ). Therefore, in the present invention, the quantification of the specific lanthanoid using the above-mentioned scanning X-ray fluorescence analyzer identifies the glaze layer 20 by the content (mass %) of the specific lanthanoid in a region approximately 50 μm deep from the outermost surface of the glaze layer 20.

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

Other Glaze Materials The glaze layer 20 includes materials typically used in glazes, such as SiO ₂ , Al ₂ O ₃ , divalent metal oxides, and monovalent metal oxides, along with an antiviral agent (specific lanthanoid).
According to a preferred embodiment of the present invention, the weight percentage of _SiO2 relative to the glass component is _52-76 %, the weight percentage of _Al2O3 relative to the glass component is 6-14%, the weight percentage of divalent metal oxide relative to the glass component is 11.4-27.6%, and the weight percentage of monovalent metal oxide relative to the glass component is 1.5-6.5%.

The glaze layer 20 is mainly composed of SiO2, _Al2O3 , divalent metal _{oxides ,} and _monovalent metal oxides, but may also contain _Fe2O3 , _TiO2 , _{V2O5 ,} etc. As divalent metal oxides, alkaline earth metal oxides such as CaO and MgO, ZnO, CuO, etc. As monovalent metal oxides, _Na2O , _K2O , _Li2O , etc. can be used.

In the present invention, the preferred compositions of the glaze materials other than the antiviral agent (specific lanthanide) are, for example, as shown in Table 1 below.

Presence state of antiviral agent in glaze layer 20 In the present invention, the antiviral agent (specific lanthanoid) is preferably present in an amorphous (non-crystalline) state at least on the surface of the glaze layer 20. By the antiviral agent being present 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 viruses attached to the glaze layer surface. In addition, because the antiviral agent is present in an amorphous state, the effect on the surface properties of the glaze layer surface can be suppressed.

In the present invention, it is more preferable that the antiviral agent (specific lanthanoid) is present in a vitrified state at least on the surface of the glaze layer 20. By having the antiviral agent present in a vitrified state on the surface of the glaze layer 20, the antiviral agent can be more efficiently 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. In addition, because the antiviral agent is present in a vitrified state, the effect on the surface properties of the glaze layer surface can be suppressed.

The fact that the antiviral agent (specific lanthanoid) is present 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: X'Pert PRO manufactured by PANalytical is used to perform the measurement under the following conditions, and if no peak is observed, it is confirmed that the agent is not crystalline, that 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: 45 V, applied current: 40 mA

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 the precipitation of particles due to crystallization is suppressed in the glaze layer, which results in the effect that the specific lanthanoid is easily stably eluted on the surface of the glaze layer and that the effect of the specific lanthanoid being present on the surface of the glaze layer on the surface of the glaze layer is further suppressed. In particular, with regard to elution, by the antiviral agent undergoing spinodal phase separation on the surface of the glaze layer 20, the antiviral agent can be stably ionized and eluted from the surface of the glaze layer, making it possible to inactivate viruses attached to the surface of the glaze layer even more efficiently, and thus exhibiting high antiviral properties.

As described below, spinodal phase separation of the antiviral agent is achieved by firing the ceramic base 10 and the glaze that forms the glaze layer 20 together once and then cooling them. Specifically, by firing the ceramic base 10 and the glaze for forming the glaze layer 20 together once and cooling them, it is possible to induce the phase separation phenomenon of glass. Phase separation of glass is a phenomenon in which single-phase glass separates into multiple phases. When glass consisting of multiple components exists as a uniform liquid phase (molten glass), there exists a region in which the free energy is lower in a two-phase mixture state than in a single-phase state as the temperature decreases. The molten glass placed in such a region separates into two phases because it is thermodynamically more stable when separated into two phases.

In the present invention, a glaze consisting of multiple components such as SiO ₂ , metal oxides, and lanthanoid oxides becomes a uniform (single) glass liquid phase (glass melt) by firing. This glass melt is placed in a metastable immiscible region by cooling to a temperature below the liquidus line in the phase equilibrium diagram of glass. The metastable immiscible region includes (i) a binodal region in which the glass melt undergoes phase separation by 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 is dispersed in the form of spherical particles that are not entangled with the other, and in the spinodal region, one of the two phases formed by phase separation is dispersed in a nonspherical shape that is highly entangled with the other. Theoretically, it is believed that the specific lanthanoid can be in both a spinodal phase separation state and a binodal phase separation state in the glaze layer, but in the present invention, by integrally firing the pottery body 10 and the glaze for forming the glaze layer 20 and cooling it, it is possible to make the specific lanthanoid exist in a rich state near the surface of the glaze layer, and to make the proportion of lanthanoids existing in the spinodal phase separation state higher than the proportion of lanthanoids existing in the surface of the glaze layer that exist in the binodal phase separation state, although the details of the mechanism are not clear. This has been confirmed by experiments, as described later, and, for example, as shown in Figures 2 to 11, the specific lanthanoid exists in a rich state near the surface of the glaze layer 20, and this specific lanthanoid exists in a spinodal phase separation state.
In addition, the mode in which the specific lanthanoid is present in the vicinity of the surface of the glaze layer in a spinodal phase separation state includes a state in which a specific lanthanoid-rich phase is present entangled with a phase (-Si-O- structure) that is not rich in the specific lanthanoid, a state in which a specific lanthanoid-rich portion is present more entangled with a portion that is not rich in the specific lanthanoid (i.e., exists uniformly with higher resolution), etc., in which a specific lanthanoid-rich portion cooperates with other portions in the glass matrix structure on the surface of the glaze layer to form an entangled structure as a whole. The presence of the specific lanthanoid in such a state in the vicinity of the surface of the glaze layer enables or promotes the specific lanthanoid to be eluted uniformly from the surface of the glaze layer when viewed macroscopically, and as a result, it is believed that high antiviral properties are exhibited.

The present invention requires that a region where the antiviral agent 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 the antiviral agent has undergone binodal phase separation is present at a lower ratio than the region where the antiviral agent has undergone spinodal phase separation due to unavoidable circumstances, for example, in the process of manufacturing the glaze layer 20, within the scope of the effects of the present invention not being impaired.

In addition, because the antiviral agent is present in a spinodal phase separation state on the surface of the glaze layer 20, it exhibits a white color due to scattering at the interface between the two phases, making it possible to realize a glaze layer surface with excellent image clarity, as described below.

In the present invention, in order to exert practical virus activity, the amount of specific lanthanoid ions eluted on the surface of the glaze layer 20 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
In a preferred embodiment of the present invention, the amount of the specific lanthanoid eluted is approximately 1 to 2% of the content of the specific lanthanoid contained in a region extending from the surface of the glaze layer toward the pottery body (the direction of the arrow in FIG. 1) to a depth of 10 nm.

surface texture
Average roughness (Ra)
The glaze layer 20 has a surface roughness (Ra) of less than 0.07 μm. With a surface roughness (Ra) of less than 0.07 μm, urinary stones, mold, yellowing, and other stains are less likely 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 maintained in a clean state for a long period of time without the need for frequent cleaning operations.

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 resistance to adhesion of dirt and the ease of removal are further improved.

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

The DOI value of the glaze layer 20 is preferably 80 or more on its surface as measured by a wavescan DOI measuring device. In the present invention, the "DOI value" refers to the DOI value measured by a wavescan DOI measuring device, for example, a Wave-Scan DIO (orange peel measuring device) manufactured by BYK Gardner (Germany). In the present invention, the DOI value is used as an index representing the image clarity of the surface of the glaze layer of the sanitary ware according to the present invention. "Image clarity" represents 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 recognized by human vision.

When the DOI value of the surface of the glaze layer 20 is 80 or more, the viewer is given an impression of excellent image clarity, resulting in the sanitary ware having a luxurious feel. In addition, good image clarity makes dirt adhering to the sanitary ware more noticeable, allowing the adhesion of filth, including viruses, to be detected early, thereby preventing the adhesion of filth, etc. 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.

The Wavescan DOI measuring device moves a laser point source over the surface of the glaze layer to scan it, measuring the brightness/darkness of the reflected light point by point at a set interval, like the human eye, to detect the optical profile of the glaze layer surface, and furthermore, this optical profile is spectrally analyzed through a frequency filter to analyze the structure of the glaze layer surface. In the microwave scan using the device, the laser point source irradiates the glaze layer surface with laser light at an angle of 60° from the perpendicular line, and the detector measures the reflected light at the same angle opposite to the perpendicular line. The characteristic spectrum of the device is as follows:
du: wavelength 0.1 mm or less Wa: wavelength 0.1 to 0.3 mm
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 0.3 mm or less. Here, DOI is a parameter consisting of du, Wa, and Wb, and is expressed as DOI=f(du, Wa, Wb).

Color difference: ΔE* value In the present invention, the glaze layer 20 preferably has a color difference: ΔE* value of its surface of 1.20 or less. When the ΔE* value of the surface of the glaze layer 20 is 1.20 or less, a sanitary ware with excellent light resistance can be obtained. The ΔE* value is measured by carrying out a weather resistance test using a sunshine carbon arc lamp weather resistance tester (manufactured by Suga Test Instruments Co., Ltd., S-300) in accordance with the sunshine carbon arc lamp method described in Chapter 9, Section 8 of JIS K5400 (1990). The test time is 8 hours, and the L*, a*, and b* values of the photocatalyst-coated body before and after the test are measured by the SCE method to obtain the color difference: ΔE* = [(ΔL*) ² + (Δa*) ² + (Δb*) ² ] ^1/2 . A color difference meter (manufactured by Konica Minolta, Inc., 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.

In the present invention, the 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 of such a thickness can achieve the above-mentioned surface properties.

Manufacturing Method The sanitary ware according to the present invention can be preferably manufactured by the following method.

First, prepare a ceramic base 10. The ceramic base 10 may be a conventionally known sanitary ceramic base slip prepared from raw materials such as silica sand, pottery stone, clay, etc., which is appropriately shaped.

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

The glaze slurry for forming the glaze layer 20 can be prepared, for example, as follows.
EMBODIMENT 1
A glaze material having the composition shown in Table 1, water, and a dispersion medium (e.g., alumina balls) are placed in a ceramic pot and pulverized, for example, by a ball mill to obtain a glaze slurry precursor. An antiviral agent compound is added to this glaze slurry precursor, and the mixture is mixed and pulverized to obtain a glaze slurry for forming the glaze layer 20.
EMBODIMENT 2
A glaze material having the composition shown in Table 1 is melted at a predetermined temperature and cooled to obtain a frit raw material. An antiviral compound is added to this frit raw material, and water, a dispersion medium, and other raw materials (e.g., pottery stone, ZnO, etc.) are further added as necessary. 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.

According to a preferred aspect of the present invention, in the above-mentioned embodiments 1 and 2, it is preferable that the average particle size of the antiviral agent after pulverization is approximately the same as the average particle size of the glaze material after pulverization. For example, it is preferable that the average particle size of the antiviral agent and the glaze material is approximately the same, being 10 μm or less, preferably about 6 to 7 μm. Here, the average particle size means the so-called 50% particle size in particle size distribution data measured by a laser diffraction method. In addition, the average particle size being "approximately the same" means that the ratio of the average particle size of the antiviral agent to the average particle size of the glaze material (the former/the latter) is within the range of 0.9 to 1.1.

By aligning the average particle size of the antiviral agent and the glaze material in this way, the antiviral agent (specific lanthanide) can undergo spinodal phase separation on the surface of the glaze layer 20, and the above-mentioned surface properties (Ra, DOI value, ΔE* value) can be achieved.

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

Then, the pottery base 10 to which the glaze slurry for forming the glaze layer 20 has been applied is fired. That is, the pottery base 10 and the glaze slurry are fired together. The firing temperature is preferably a temperature at which the sanitary ware base sinters and the glaze softens, and is 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 firing together only once. The inventors have confirmed through experiments that crystallization of the antiviral agent is suppressed by performing the firing together only once. Specifically, it has been confirmed that crystals precipitate from the amorphous layer of the glaze layer when firing is performed multiple times, and that crystals precipitate when the second firing is performed at a temperature lower than the first firing temperature, for example.

The resulting fired body is then cooled. The cooling conditions are not particularly limited, and may be natural cooling or the temperature and time may be appropriately controlled.

The ceramic base 10 and the glaze slurry, which has been prepared so that the average particle size of the antiviral agent is approximately the same as that of the other glaze materials, are fired once together at a temperature lower than the melting point of the antiviral agent, and then cooled, whereby the antiviral agent is preferably vitrified while suppressing crystallization, 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, thereby obtaining a glaze layer 20 on whose surface there is an abundance of regions in which the antiviral agent has undergone spinodal phase separation.

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

Preparation of Pottery Base: Pottery base slurry was prepared from raw materials such as silica sand, feldspar, and clay, and a plate-shaped test piece of 70 mm x 150 mm was prepared using the slurry.

Preparation of glaze slurry for forming 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 ceramic pot, and pulverized in a ball mill so that the particle size measurement result of the glaze slurry after pulverization using a laser diffraction particle size distribution analyzer showed that 65% of the particles were 10 μm or less and the 50% particle size was about 6.5 μm, thereby obtaining a glaze slurry for forming a base glaze layer.

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 ground in a ball mill so that the particle size measurement result of the glaze slurry after grinding using a laser diffraction particle size distribution analyzer was 65% 10 μm or less and 50% particle size (D50) was 6.5 μm, to obtain a glaze slurry precursor. 5% by weight of the lanthanoid oxide shown in Table 4 was added to this glaze slurry precursor (i.e., 5% by weight of the lanthanoid oxide was added to the total content of the glaze material 100% by weight), mixed, and ground in a ball mill so that 65% 10 μm or less and 50% particle size (D50) was 6.5 μm, to prepare the antiviral glaze slurries for sanitary ware of Examples 1 to 9 and Comparative Example 1.

The antiviral glaze slurries prepared as above were applied to the above-mentioned ceramic base test pieces by spray coating. 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 9 and Comparative Example 1.

Evaluation The sanitary wares of Examples 1 to 9 and Comparative Example 1 were evaluated as follows.

Content of Antiviral Agent The content of the specific lanthanide contained in the glaze layers of the sanitary ware of Examples 1 to 9 and Comparative Example 1, based on the amount of specific lanthanide oxide, is calculated as 5 wt%/(100 wt% + 5 wt%) × 100 ≒ 4.8%, as the percentage of lanthanum oxide (5 wt%) to the total (105 wt%) of 100 wt% of the glaze material and 5 wt% of lanthanum oxide shown in Table 1. The same applies to the other Examples 2 to 9 and Comparative Example 1.

Antiviral Activity 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 9, Comparative Example 1, and, as a control, sanitary ware in which the glaze layer did not contain the antiviral agent, and then the sanitary ware was covered with a film.
Each piece of sanitary ware was left standing at 25°C for 24 hours.
After leaving the samples to stand, the viruses on each piece of sanitary ware were washed away and collected, and the viral infectivity was then measured.
- The antiviral activity value was calculated using the following formula.
R = Ut - At
R: antiviral activity value Ut: common logarithm of the viral infectivity (PFU/cm ² ) of the control sanitary ware after standing for 24 hours At: common logarithm of the viral infectivity (PFU/cm ² ) of the sanitary ware of Examples 1 to 9 and Comparative Example 1 after standing for 24 hours The antiviral activity values of the sanitary ware of Examples 1 to 9 and Comparative Example 1 are shown in Table 4.
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.

DOI value : Wave-Scan DOI measuring device: The DOI value was measured using a Wave-Scan DIO (orange peel measuring device) manufactured by BYK Gardner (Germany). The results are shown in Table 4.

Confirmation of the state of specific lanthanides near the surface of the glaze layer <XRD measurement>
XRD device: X'Pert PRO manufactured by PANalytical was used, and measurements were carried out under the following conditions.
XRD measurement conditions Measurement range: 3° to 60°
Scan 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 the specific lanthanoid. Therefore, it was confirmed that the specific lanthanoid is present in an amorphous (non-crystalline) state or a vitrified state on the surface of the antiviral glaze layer.

<SEM Observation>
The presence of the specific lanthanoid near the surface of the antiviral glaze layer was observed by SEM. The SEM observation was performed using an apparatus: S4800 (manufactured by Hitachi High-Technologies Corporation) under the conditions of magnification of 50,000 times, applied voltage of 2.0 kV, and applied current of 20 mA (2.0 mm x 50.0 k SE (U, LA100)). SEM images are shown in Figures 3 to 11. Each figure A is a surface SEM image of the antiviral glaze layer, and each figure B is a cross-sectional SEM image of the antiviral glaze layer. In both figures A and B, the white part indicates the presence of the specific lanthanoid, and the black part indicates the Si-O structure. In figure B, the part that looks like a boundary line indicates the state in which the specific lanthanoid is rich in the white part. The image area above the white part is an air area, so it is not observed.
From each figure, it was confirmed that the specific lanthanoid is present in abundance in the glaze layer, particularly near the surface of the glaze layer, that the specific lanthanoid undergoes spinodal phase separation, and further that the spinodal dispersion region of the specific lanthanoid is enriched near the surface of the glaze layer.

また、表４に示される結果から、Ｃｅを含む比較例１の衛生陶器にあっては、抗ウイルス活性値が低く、表面性状（Ｒａ値およびＤＯＩ値）も不良であるのに対し、特定ランタノイドを含む実施例１～９の衛生陶器にあっては、抗ウイルス活性値が高く、表面性状（Ｒａ値およびＤＯＩ値）も良好であることが確認された。つまり、本発明による衛生陶器が、実用的な抗ウイルス性と、汚れに対する優れた難付着性・易除去性とを併せ持ち、これらの性能を相乗的に発揮することが確認された。

Furthermore, it was confirmed from the results shown in Table 4 that the sanitary ware of Comparative Example 1, which contained Ce, had a low antiviral activity value and poor surface properties (Ra value and DOI value), whereas the sanitary ware of Examples 1 to 9, which contained a specific lanthanoid, had a high antiviral activity value and good surface properties (Ra value and DOI value). In other words, it was confirmed that the sanitary ware of the present invention has both practical antiviral properties and excellent resistance to adhesion of dirt and easy removal of dirt, and that these performances are exerted synergistically.

Confirmation of the presence (distribution) state of the antiviral agent in the glaze layer based on the content of the antiviral agent In the sanitary ware of Example 1 described above, the sanitary ware of Examples 1 to 15 in which the lanthanum content was varied were produced in the same manner as in the production method of Example 1.
The amounts (wt %) of lanthanum contained in the glaze layers of the sanitary ware of Examples 1 to 15 calculated as lanthanum oxide (La ₂ O ₃ ) and the atomic abundances (mass %) measured by XRF were as shown in Table 5.
The lanthanum content (wt%) of each sanitary ware shown in Table 5, calculated as the amount of lanthanum oxide (La ₂ O ₃ ), for example, for the sanitary ware of Example 4, was calculated as the percentage of lanthanum oxide (5 wt%) to the total (105 wt%) of 100 wt% of the glaze material and 5 wt% of lanthanum oxide shown in Table 1, as 5 wt%/(100 wt% + 5 wt%) x 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.
Comparing the lanthanum content (wt%) based on _the lanthanum oxide ( _La2O3 ) equivalent amount of each sanitary ware with the lanthanum content (mass%) measured by XRF, it was confirmed that the latter was greater. This indicates that the lanthanum content near the surface of the antiviral glaze layer is greater than the lanthanum content in the entire antiviral glaze layer. In other words, it indicates that lanthanum is concentrated near the surface of the antiviral glaze layer.
Therefore, according to the present invention, the antiviral agent (specific lanthanoid) can be concentrated near the surface of the glaze layer, and as a result, good antiviral properties can be exhibited. Furthermore, according to the present invention, even a small amount of the antiviral agent can be concentrated near the surface of the glaze layer, so that good antiviral properties are efficiently exhibited and, because the amount of the antiviral agent is small, the Si-O structure of the glaze layer is not affected, that is, a sanitary ware in which excellent surface properties are maintained can be realized.

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

Relationship Between the Content of the Antiviral Agent, the Amount of the Antiviral Agent Eluted, and the Antiviral Activity Value Furthermore, the relationship between the content of the antiviral agent, the amount of the antiviral agent eluted, and the antiviral activity value in the sanitary ware of Examples 1 to 15 was confirmed.
Fig. 12A shows the relationship between the amount of lanthanum in terms _of lanthanum oxide ( _La2O3 ) (wt% ₎ and the amount of lanthanum dissolved (ppm) on the glaze layer surface. Fig. 12B shows the relationship between the amount of lanthanum dissolved and the antiviral activity value. Fig. 13A shows the relationship between the amount of lanthanum in terms of lanthanum oxide ( _La2O3 ) (wt%) and the atomic abundance (mass%) measured by XRF. Fig. 13B shows the relationship between the atomic abundance (mass%) of lanthanum measured by XRF and the antiviral activity value.
12 and 13, it was confirmed that a proportional relationship exists between the amount of lanthanum converted to lanthanum oxide (La ₂ O ₃ ) (wt %) and the atomic abundance (mass %) of lanthanum measured by XRF, that a proportional relationship exists between the lanthanum content and the amount of lanthanum eluted onto the glaze layer surface, and that a proportional relationship also exists between the amount of lanthanum eluted and the antiviral activity value.

Confirmation of the relationship between firing conditions, spinodal phase separation amount, and antiviral activity value The amount of lanthanum oxide added was 10 wt %, and the antiviral glaze slurry prepared by the above Preparation Example was applied to the above ceramic base test piece by spray coating. After that, it was fired in a kettle under the following conditions 1 to 3 to produce three types of sanitary ware A to C.
Sanitary ware A: Firing condition 1 (firing temperature: 1200°C, total firing time: 10 hours)
Sanitary ware B: Firing condition 2 (firing temperature: 1200°C, total firing time: 15 hours)
Sanitary ware C: Firing condition 3 (firing temperature: 1200°C, total firing time: 20 hours)
The antiviral activity values of the sanitary ware A to C are shown in Table 6 below. The state of lanthanum present near the surface of the antiviral glaze layer of the sanitary ware A to C is shown in Figures 14A to 14C.

表６、図１４Ａ～Ｃから、酸化ランタンの添加量および焼成温度を同一とした条件下において、焼成時間を短く設定して製造した衛生陶器Ａは、高い抗ウイルス性を有し、さらに釉薬層２０の表面付近にランタンがスピノーダル分相し、また分相領域がリッチであることが確認された。一方、設定時間を長く設定した衛生陶器Ｂは、バイノーダル分相とスピノーダル分相が混在しており、衛生陶器Ａに比べて低い抗ウイルス性を有し、さらに設定時間を長く設定した衛生陶器Ｃは、衛生陶器Ａ、Ｂに比べて低い抗ウイルス性を有することが確認された。なお、釉薬層２０の表面付近にランタンなどの特定のランタノイドをスピノーダル分相で存在させる方法は、上述するように粒子径や焼成時間を調整する以外に当業者であれば様々な手法を採用することができる。

From Table 6 and Figures 14A to 14C, it was confirmed that, under the same conditions of the amount of lanthanum oxide added and the firing temperature, sanitary ware A, which was produced by setting the firing time to a short time, had high antiviral properties, and furthermore, lanthanum underwent spinodal phase separation near the surface of the glaze layer 20, and the phase-separated region was rich. On the other hand, it was confirmed that sanitary ware B, which was produced by setting the firing time to a long time, had a mixture of binodal and spinodal phase separation, and had lower antiviral properties than sanitary ware A, and sanitary ware C, which was also produced by setting the firing time to a long time, had lower antiviral properties than sanitary ware A and B. Note that, as a method for causing a specific lanthanoid such as lanthanum to exist near the surface of the glaze layer 20 in the form of a spinodal phase, those skilled in the art can employ various methods other than adjusting the particle size and firing time as described above.

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

Claims (7)

A sanitary ware comprising a ceramic base and a glaze layer formed on a surface of the ceramic base,
The glaze layer contains a lanthanoid as an antiviral agent,
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) ;
The lanthanum (La) content (oxide equivalent) 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 neodymium (Nd) content (in terms of oxide) is 1.0% by weight or more and 20.0% by weight or less,
The samarium (Sm) content (in terms of oxide) is 1.1% by weight or more and 22.0% by weight or less,
The gadolinium (Gd) content (in terms of oxide) is 1.1% by weight or more and 22.0% by weight or less,
The terbium (Tb) content (in terms of oxide) is 1.1% by weight or more and 22.0% by weight or less,
The dysprosium (Dy) content (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,
1. A sanitary ware comprising: a sanitary ware having a porcelain lining; and a sanitary ware having a porcelain lining, the sanitary ware being characterized in that the antiviral agent is present in an amorphous (non-crystalline) state on at least a surface of the glaze layer. The sanitary ware of claim 1, characterized in that the glaze layer has a DOI value of 80 or more on its surface as measured by a wavescan DOI measuring device. 3. The sanitary ware according to claim 1 , wherein the antiviral agent is subjected to spinodal phase separation at least on a surface of the glaze layer. The sanitary ware according to any one of claims 1 to 3 , further comprising a base glaze layer between the ceramic body and the glaze layer. A method for producing the sanitary ware according to any one of claims 1 to 4 ,
The process of preparing the pottery base,
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;
applying the glaze slurry to a surface of the ceramic body;
and firing the pottery body to which the glaze slurry has been applied to form a glaze layer. The method according to claim 5 , characterized in that the ratio (former/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 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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