JP7365128B2 - Ceramic decorative board - Google Patents

Description

The present invention relates to a ceramic decorative board with excellent antibacterial and antifungal properties.

Ceramic decorative boards made of ceramic materials such as fiber-reinforced cement boards are widely used as exterior and interior materials because they have sufficient nonflammability and strength. These ceramic decorative boards usually have a colored layer and/or a clear layer formed on at least one surface of the substrate in addition to a sealer layer and an undercoat layer (Patent Documents 1 to 3).

On the other hand, interior materials for food factories and kitchens are required to have antibacterial and antifungal properties, and ceramic decorative laminates are also required to have antibacterial and antifungal properties in addition to high noncombustibility and strength.

Japanese Unexamined Patent Publication No. 168584/1984 Japanese Patent Application Publication No. 2013-240935 Japanese Patent Application Publication No. 2015-120339

However, ceramic decorative boards with an acrylic urethane resin film formed on the colored layer or clear layer have excellent stain resistance, due to the strong crosslinked structure and good film forming properties that are characteristic of acrylic urethane resin. Although it has elasticity and adhesion, it has been found that it has the disadvantage that it is difficult to impart antibacterial and antifungal functions. The antibacterial/fungal agent mixed into the paint has good antibacterial and fungicidal properties because it is partially exposed from the surface of the paint film or exists in a state where it can come into contact with moisture etc. adhering to the surface of the paint film. It is thought that this effect is exerted. However, it is highly likely that the high film-forming properties of acrylic urethane resins, which are suitable as paints, suppress the functions of such antibacterial and fungicidal agents. In fact, if the amount of antibacterial/fungicidal agent added to the paint is increased, the proportion of the agent exposed on the surface of the paint film will increase, so the antibacterial/fungal effect can be easily enhanced. However, adding large amounts of antibacterial and fungicidal agents will not only reduce the performance of the coating film but also increase the risk of the harmful effects of the antibacterial and antifungal agents, resulting in a loss of safety as a decorative board.
SIAA (Antibacterial Product Technology Council) evaluates and examines the safety and appropriate concentration of fungicides that are particularly likely to contain harmful substances, with the aim of disseminating appropriate and safe antibacterial and antifungal products. We have established a registration system and published a positive list. Here, the term "antibacterial/antifungal agent" is a general term for functional additives that exhibit both antibacterial and antifungal properties, including those generally sold as antibacterial agents or antifungal agents.
Therefore, the problem of the present invention is to use highly safe antibacterial and fungicidal agents in accordance with SIAA guidelines at appropriate concentrations in ceramic decorative boards in which colored and clear layers are coated with acrylic urethane resin. Another object of the present invention is to provide a decorative board that has excellent antibacterial and antifungal properties.

Therefore, the present inventor investigated how to impart antibacterial and fungicidal properties to the acrylic urethane resin layer of ceramic decorative laminates, and found that (a) metal ion-based antibacterial and fungicidal agents and (b) organic nitrogen sulfur-based agents, etc. By using a certain organic antibacterial/fungal agent in combination, a ceramic decorative board can be obtained that has excellent antibacterial and fungicidal properties with a small amount of addition, and also maintains the light resistance and other properties of acrylic urethane resin. The present invention was completed based on this discovery.

That is, the present invention provides the following inventions [1] to [6].

[1] A ceramic decorative board having a colored layer and/or a clear layer containing an acrylic urethane resin on the outermost layer of at least one side of a ceramic substrate, the colored layer and/or the clear layer containing ( A ceramic decorative board characterized by containing a) a metal ion antibacterial/fungal agent and (b) an organic antibacterial/fungal agent selected from organic nitrogen sulfur, organic bromo, and organic nitrogen based antibacterial/fungal agents.
[2] (a) The ceramic decorative board according to [1], wherein the metal ion-based antibacterial/fungal agent is one or more selected from silver ion-based antibacterial/fungal agents and zinc ion-based antibacterial/fungal agents. .
[3] (b) The ceramic decorative board according to [1] or [2], wherein the organic antibacterial/fungal agent is one or more selected from organic nitrogen-sulfur antibacterial/fungal agents.
[4] The total content of (a) metal ion antibacterial/fungal agent and (b) organic antibacterial/fungal agent is 1.5 to 3 parts by mass per 100 parts by mass of solid content in the acrylic urethane paint. The ceramic decorative board according to any one of [1] to [3].
[5] The mass ratio (a/b) of (a) metal ion antibacterial/fungal agent to (b) organic antibacterial/fungal agent is 0.5 to 3 [1] to [4] The ceramic decorative board described in any of the above.
[6] (b) The organic antibacterial/fungal agent is one or more organic nitrogen sulfur-based antibacterial/fungal agents selected from alkylene bisthiocyanates, 3-isothiazolone compounds or salts thereof, and thiadiazine compounds. The ceramic decorative board according to any one of [1] to [5].

The ceramic decorative board of the present invention has excellent antibacterial and antifungal properties, as well as excellent nonflammability, strength, light resistance, etc., and is therefore useful as an interior material for schools, hospitals, food factories, kitchens, etc. .

The antibacterial test process is shown. An outline of the antibacterial test method is shown.

The ceramic decorative board of the present invention is a ceramic decorative board having a colored layer and/or a clear layer containing an acrylic urethane resin on the outermost layer of at least one side of a ceramic substrate, the colored layer and/or the clear layer containing an acrylic urethane resin. Or, the clear layer contains (a) a metal ion-based antibacterial/fungal agent and (b) an organic antibacterial/fungal agent selected from organic nitrogen-sulfur, organic bromo-based, and organic nitrogen-based antibacterial/fungal agents. do.

The substrate for the ceramic decorative board of the present invention (ceramic substrate, hereinafter also simply referred to as substrate) includes fiber-reinforced cement boards (including calcium silicate boards), wood-based cement boards, wood wool, etc. that form the walls of houses, etc. Examples include cement laminate boards, volcanic glass multilayer boards, extruded cement boards, slag gypsum boards, lightweight cellular concrete boards, glass boards, and ceramic boards.
Among these substrates, fiber-reinforced cement boards are more preferred.

These substrates use, for example, hydraulic cement such as Portland cement as the main raw material to form the matrix, fibers other than asbestos as the fiber raw material, and, if necessary, wollastonite, calcium carbonate powder, etc. This is a substrate using an admixture of 100% as a raw material, specifically a substrate such as a fiber-reinforced cement board specified in JIS A 5430. In particular, a 0.8 calcium silicate board, which is a type of fiber-reinforced cement board, and a 1.0 The calcium acid board is a substrate with excellent flexibility, has high strength, and has a small rate of change in length due to water absorption, and is therefore suitable as a substrate for the ceramic decorative board of the present invention.

Examples of the fiber materials include organic fibers such as pulp, synthetic pulp, polypropylene fibers, rayon fibers, acrylic fibers, vinylon fibers, nylon fibers, and polyester fibers; metal fibers such as steel fibers (steel wire fibers) and amorphous metal fibers; Examples include glass fiber, carbon fiber, rock wool fiber, and inorganic fibers such as whiskers. However, in the present invention, even if the autoclave curing described above is adopted, the reinforcing properties and toughness of the decorative board can be improved. It is preferable to use pulp from the viewpoint of improved performance. Note that the pulp here refers to a product obtained by mechanically or chemically treating a plant material such as wood to extract cellulose, and refers to a so-called cellulose pulp.
The content ratio of fibers, especially organic fibers such as pulp, in the fiber-reinforced cement board varies depending on the matrix, but from the viewpoint of ensuring strength and nonflammability, it is preferably 5 to 9% by mass, and 6 to 8% by mass. % is more preferable. If the content ratio of organic fibers such as pulp is low, the mechanical strength of the decorative board will decrease, making it more likely to crack due to heat load, drying, carbonation, or impact. Conversely, if the content of organic fibers such as pulp is high, it becomes difficult to maintain nonflammability.

The hydraulic cement may be any one commonly used in the industry, such as Portland cement.
Various additives that may be used as necessary include those commonly used in the industry, and are not particularly limited, such as powders such as wollastonite, mica, and calcium carbonate, and fiber-reinforced cement board thinning materials. Examples include scrap board powder. In addition, when performing autoclave curing, silicic acid raw materials such as crystalline silica such as powdered silica, amorphous silica such as fly ash, etc. It is recommended to add calcareous raw materials such as quicklime, slaked lime, etc. as necessary, and adjust the molar ratio of the matrix components CaO/SiO ₂ to 0.7 to 1.2. preferable.

In the present invention, the thickness of the substrate is preferably 3 to 12 mm, more preferably 4 to 8 mm, from the viewpoints of impact resistance, light weight, and workability.

Further, in the present invention, the bulk density of the substrate is preferably 0.6 to 1.8 g/cm ³ from the viewpoint of lightness, mechanical strength, and workability, and preferably 0.6 to 1.2 g/cm ³ . is even more preferable.

Further, in the present invention, the total calorific value of the substrate is preferably 5 MJ/m ² or less, more preferably 4.7 MJ/m ² or less, from the viewpoint of nonflammability.

In the present invention, the thickness of the substrate or decorative board is a value measured according to JIS A 5430:2018, Section 8.2.2 b). The bulk density is a value measured according to JIS A 5430:2018, Section 8.5.
The total calorific value of the substrate is a value measured according to JIS A 5430:2018, Annex JA.

The substrate has a colored layer and/or a clear layer containing an acrylic urethane resin on the outermost layer of at least one side of the substrate.
The thickness of the colored layer is preferably 5 to 40 μm, more preferably 10 to 40 μm, and even more preferably 15 to 35 μm.
The colored layer contains an inorganic colored pigment. Examples of inorganic coloring pigments contained in the colored layer include titanium oxide, zinc white, red iron, loess, chromium oxide green, dark blue, carbon black, iron black, etc., and one or two types selected from these. It is more preferable to use a combination of the above. Moreover, an organic pigment can also be used in combination if necessary.

The method of forming the colored layer is not particularly limited, and can be selected from known methods used in normal painting, such as spraying, roll coater, flow coater, etc. Among them, coating with a roll coater or flow coater is preferred. In the case of overcoating in two or more times, these may be used in combination as appropriate.

In the present invention, the amount of organic solid content in the components of the colored layer is preferably set to 5 to 35 g per unit area (m ² ) of the substrate, and more preferably 10 to 30 g.

The ceramic decorative board of the present invention may have a clear layer on the surface of the colored layer. The thickness of the clear layer is preferably 5 to 50 μm, more preferably 10 to 40 μm.

As a coating method for forming the clear layer, existing methods such as a flow coater, roll coater, and spray coater can be applied. The dry coating amount of the clear layer is preferably 5 to 100 g, more preferably 10 to 80 g per unit area (m ² ) of the substrate. Further, from the viewpoint of ensuring nonflammability, the amount of organic solid content in the clear layer is preferably 4 to 45 g, more preferably 8 to 35 g per unit area (m ² ) of the substrate.

Furthermore, in the ceramic decorative board of the present invention, a printed layer may be provided between the colored layer and the clear layer. By providing a printed layer, a pattern such as a wood grain or stone grain pattern can be imparted to the decorative board. As a method for printing, existing methods such as gravure printing, gravure offset printing, inkjet printing, screen printing, rotary screen printing, letterpress printing, and pad printing can be applied.

The paint used for these colored layers and/or clear layers is a paint containing an acrylic urethane resin, and a two-component curable acrylic urethane resin paint is more preferable.

In the ceramic decorative board of the present invention, the colored layer and/or clear layer contains (a) a metal ion antibacterial/fungal agent and (b) an organic nitrogen sulfur agent, an organic bromo agent, and an organic nitrogen agent. Contains organic antibacterial and antifungal agents.
By incorporating these two types of antibacterial and fungicidal agents into the colored layer and/or clear layer containing acrylic urethane resin, excellent antibacterial and fungicidal properties can be obtained with a small amount of addition, as well as improvements in light resistance, etc. Characteristics are also preserved.

(a) Examples of metal ion-based antibacterial/fungal agents include silver ion-based antibacterial/fungal agents, zinc ion-based antibacterial/fungal agents, copper ion-based antibacterial/fungal agents, etc. One or more types selected from antibacterial/fungal agents and zinc ion-based antibacterial/fungal agents are more preferable.

Among metal ion-based antibacterial/fungal agents, organic active ingredients include organic complexes containing ions selected from silver ions, copper ions, and zinc ions, such as organic silver complexes and organic zinc complexes. In addition, examples of inorganic active ingredients include those in which silver ions, zinc ions, copper ions, etc. are supported on silicate-based carriers (zeolite, etc.), phosphate-based carriers, silica-based carriers, and glass-based carriers. . Examples of organic zinc complexes include zinc pyrithione (bis(2-mercaptopyridine-N-oxide) zinc (II)) and the like.
Note that when only these active ingredients are used as antibacterial/fungal agents, the amount required may be extremely small, so if it becomes difficult to control the concentration or ensure dispersibility, dispersion aids may be used. It is sometimes used as an antibacterial and fungicidal agent by mixing it with clay mineral powder, etc., which acts as an agent. Examples of clay minerals suitable for mixing include kaolinite, bentonite, talc, and the like.

Active ingredients of organic nitrogen sulfur-based antibacterial/fungal agents include alkylene bisthiocyanates, 3-isothiazolone compounds, sulfonamide compounds, and thiazole compounds. Examples of the alkylene bisthiocyanate include methylene bisthiocyanate and ethylene bisthiocyanate. Examples of 3-isothiazolone compounds include 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, and 4,5-dichloro-2-n-octyl-isothiazolin- Examples include 3-one, 2-n-octyl-isothiazolin-3-one, and 1,2-benzisothiazolin-3-one. Examples of the sulfonamide compound include chloramine T and N,N-dimethyl-N'-(fluorodichloromethylthio)-N'-phenylsulfamide. Examples of thiazole compounds include 2-(4-thiocyanomethylthio)benzothiazole and sodium 2-mercaptobenzothiazole.

Examples of organic bromo compounds include organic bromonitrile compounds such as 2,2-dibromo-2-nitro-1-ethanol, 2-bromo-2-nitro-1,3-diacetoxy-propane, and β-bromo-β-nitro. Styrene, 2,2-dibromo-3-nitrilo-propionamide as an organic bromocyano compound; 1,4-bis-(bromoacetoxy)-2-butene as an organic bromoacetate compound, bistribromo as an organic bromo sulfone compound Preference is given to using methylsulfone.

Examples of organic nitrogen compounds include hexahydro-1,3,5-tris-(2-hydroxyethyl)-S-triazine as an S-triazine compound, and N,4-dihydroxy-α-oxobenzene as a halogenated oxime compound. It is preferable to use ethanimidoyl chloride and 2-(hydroxymethylamino)ethanol as the amino alcohol compound.

Among these active ingredients, organic nitrogen sulfur compounds are preferred, and one or more selected from alkylene bisthiocyanates, 3-isothiazolone compounds or salts thereof, and thiadiazine compounds are more preferred.
Note that when only these active ingredients are used as antibacterial/fungal agents, the amount required may be extremely small, so if it becomes difficult to control the concentration or ensure dispersibility, dispersion aids may be used. It is sometimes used as an antibacterial and fungicidal agent by mixing it with clay mineral powder, etc., which acts as an agent. Examples of clay minerals suitable for mixing include kaolinite, bentonite, talc, and the like. Furthermore, substances that are liquid at room temperature may be supported on inorganic powders having a porous or layered structure to form antibacterial and antifungal agents. Examples of the inorganic powder to be supported include zeolite, hydrotalc, and the like.

From the viewpoint of antibacterial and antifungal effects, the total content of (a) metal ion antibacterial/fungal agent and (b) organic antibacterial/fungal agent is 1.0% per 100 parts by mass of solid content in the acrylic urethane paint. It is preferably 5 to 3 parts by weight, more preferably 2 to 3 parts by weight.

The content mass ratio (a/b) of (a) metal ion antibacterial/fungal agent and (b) organic antibacterial/fungal agent is preferably 0.5 to 3 from the viewpoint of antibacterial/fungal effect. It is preferably from 0.75 to 2.5, even more preferably from 1 to 2.

In the ceramic decorative board of the present invention, a sealer layer is preferably provided between the substrate and the undercoat layer, that is, on at least one side of the substrate. By providing the sealer layer, the surface layer of the substrate is strengthened, and the elution of alkali to the surface can be prevented, and the adhesion with the undercoat layer serving as the upper layer is also improved.
The sealer layer can be formed using a known sealer, for example, by applying a curable resin such as a moisture-curable urethane resin or an epoxy resin onto the surface of the substrate and curing it. The sealer is a polyisocyanate or a reaction between polyisocyanate and polyol that has good impregnation properties into the substrate, has a high non-volatile content, and reacts with moisture in the substrate and moisture in the atmosphere to three-dimensionally crosslink, and has good water resistance. Moisture-curing urethane systems based on a product prepolymer having free isocyanate groups and a solvent such as butyl acetate are preferred. Further, when yellowing as a decorative board is a problem, it is preferable to use an aliphatic isocyanate such as HDI (hexamethylene diisocyanate) or an alicyclic isocyanate such as IPDI (isophorone diisocyanate). In addition, from the perspective of recent VOC countermeasures, it is recommended to use solvent-free sealers or water-based sealers that do not contain solvents, inorganic sealers such as silicate-based sealers such as lithium silicate or sodium silicate, tetraethoxysilane, etc. A silane compound sealer containing tetramethoxysilane or the like as a main component can also be used.
The sealer layer can be formed, for example, by heating the surface of a fiber-reinforced cement board to 50 to 60°C, applying a sealer using a known method such as a roll coater or spraying method, and then curing. The viscosity of the impregnating sealer can be appropriately determined in consideration of the type of impregnating sealer used and the coating method, and curing can be performed, for example, by heating and drying.

Further, in the present invention, the back surface of the substrate can also be reinforced by impregnation sealer treatment. This is because adhesive construction is often used as a construction method for decorative boards, and workability is improved by reinforcing the back side of the board. When the back side of the substrate is also treated with an impregnation sealer, it is common to perform the impregnation sealer treatment on the back side before forming an undercoat layer, which will be described later, but it may be performed after forming the undercoat layer.

In the present invention, the amount of organic solid content in the components of the impregnating sealer is preferably set to 3 to 50 g per unit area (m ² ) of the substrate. If the amount of organic solid content is too small, the surface layer of the substrate may not be strengthened very much. In addition, there is a possibility that the adhesion with the undercoat layer that is the upper layer may be reduced. If the amount of organic solid content is too large, excess organic solid content will remain on the surface layer of the substrate, and this organic solid content may cause defects such as agglomeration and peeling within the sealer layer, foaming in post-processes, and sidewalls. There is sex. In addition, a side is a minute hole that is created when the gas in the bubble breaks through the paint film during foaming, and is caused by a locally thick film during painting, and is mainly caused by a sudden rise in temperature during drying. . The amount of organic solids in the components of the impregnation sealer is more preferably set to 10 to 40 g per unit area (m ² ) of the substrate. Further, when the back surface of the substrate is treated with an impregnating sealer, the amount of organic solid content in the components of the impregnating sealer is preferably set to 3 to 30 g per unit area (m ² ) of the substrate.

In the present invention, the organic solid content can be easily calculated from the composition of the paint stock solution, the amount of diluting solvent used, and the actual amount applied.

The ceramic decorative board of the present invention has an undercoat layer on the surface of the sealer layer. By forming the undercoat layer, large and small irregularities and voids existing on the surface of the substrate are filled with the paint, thereby suppressing unevenness and variations in gloss and color due to paint absorption spots. Also, the possibility of defects such as pinholes occurring in the decorative board is reduced.

The thickness of the undercoat layer is from 5 to 100 μm to improve the surface smoothness of the decorative board, adhesion with the upper and lower coatings, formability, waterproofness, prevention of precipitation of base material components, and coating film pinholes. The film thickness is preferably 20 to 90 μm, still more preferably 25 to 70 μm, from the viewpoints of prevention of drying, coating film hardening properties, surface foreign matter embedding property, and ease of film thickness control.

The paint for forming the undercoat layer is preferably an unsaturated polyester paint from the viewpoints of surface smoothness, chemical resistance, film adhesion, polishing workability, film hardness, ease of painting, and crack prevention properties. Specifically, allylic unsaturated polyesters such as epoxy acrylate, urethane acrylate, and diallyl phthalate; maleic unsaturated polyesters produced by polycondensation of unsaturated dibasic acids such as maleic anhydride and fumaric acid with glycols; Polyester monoacrylates with carboxyl or hydroxyl groups as functional groups, polyester diacrylates obtained from acrylic acid, dibasic acids, and dihydric alcohols, polyester polyacrylates obtained from trivalent or higher polyhydric alcohols, dibasic acids, and acrylic acid. Polyester acrylates, epoxy acrylate oligomers, oligomers such as epoxy oligomers, acrylic polyethers, polyether acrylates, and the like can be mentioned. In addition, it is recommended that the paint used to form the undercoat layer be an ultraviolet curable paint for ease of application, fast curing speed, abrasion resistance and durability of the paint film, and compatibility with the substrate and top coat paint. It is preferred because it has excellent adhesion.

The method of applying the undercoat paint includes methods using a roll coater, flow coater, etc. Among them, a roll coater is suitable, considering the effect of filling the large and small irregularities and voids on the substrate surface with the paint. There is. Furthermore, from the viewpoint of uniformly applying the paint, a flow coater is suitable.

In the present invention, the amount of organic solid content contained in the undercoat layer is preferably set to 3 to 70 g, preferably 10 to 65 g per unit area (m ² ) of the substrate.

The undercoat coating for forming the undercoat layer can be performed once to form an undercoat layer of a predetermined thickness, or can be applied two or more times to form an undercoat layer of a predetermined thickness. For example, when applying an undercoat twice to form an undercoat layer with a predetermined thickness, first apply the first undercoat with a slightly higher viscosity undercoat (200 to 600 dPa・s) to reduce the amount of UV irradiation. UV irradiation is applied in a controlled manner so that it does not completely cure, then a second undercoat is applied with a slightly lower viscosity undercoat (20 to 60 dPa・s), and then UV irradiation is applied again to coat the entire undercoat. It is best to let it harden completely. By doing this, the first undercoat has the effect of filling in the large and small irregularities and voids that exist on the substrate surface, and the second undercoat has a self-leveling effect that creates a smooth surface of the undercoat layer. Since this can be obtained, a good undercoat layer can be efficiently formed. Further, after completely curing the undercoat paint, the undercoat layer can be made to have an even smoother surface by polishing with a belt sander or the like.

Hereinafter, the present invention will be further explained with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

(1) Fiber reinforced cement board (substrate)
Hilac (manufactured by A&A Materials Co., Ltd.) was used as the substrate. Hi-Lac is a fiber-reinforced cement board that corresponds to "calcium silicate board type 2 0.8 calcium silicate board" in Table 1 of JIS A 5430. The Hi-Lac used in the Examples and Comparative Examples had a smooth surface (hereinafter referred to as "surface") on which the decorative layer was to be formed by polishing with No. 100 abrasive paper using a platen polisher. used.

(2) Formation of each coating layer Each coating layer was formed using the following paint and method.
(a) Sealer layer Polyurethane resin-based solvent-free sealer: Dainippon Toyo Co., Ltd.
The coating was applied to the surface of the substrate using a roll coater so that the organic solid content was approximately 30 g/m ² .
(b) Undercoat layer First undercoat: Modified epoxy resin ultraviolet curable undercoat paint: Dainippon Toyo Co., Ltd.
The upper layer of the sealer layer was coated using a roll coater so that the organic solid content was about 37 g/m ² .
Second undercoat: Modified epoxy resin UV-curable undercoat: Dainippon Toyo Co., Ltd.
After the first undercoat is cured to some extent by UV irradiation, it is applied using a roll coater so that the organic solid content is approximately 27 g/ ^m2 , and after the entire undercoat layer is cured by UV irradiation, a wide coating is applied. A smooth undercoat layer was obtained by polishing with abrasive paper having an abrasive count of 400 using a belt sander.
(c) Top coat layer (colored layer)
Two-component curing acrylic urethane resin paint (white): Dainippon Toyo Co., Ltd.
The upper layer of the undercoat layer was coated using a flow coater so that the organic solid content was about 22 g/m ² , and then set at room temperature and dried for 2 hours at an ambient temperature of 60° C. to form a colored layer.

(3) Addition of antibacterial and fungicidal agents At the levels shown in Table 1, each antibacterial and fungicidal agent was added in proportion to the solid content of the topcoat before forming the topcoat layer in (2) (c). A decorative board was prepared using this method and used as a test specimen. The types of antibacterial/fungal agents used are as follows.
A: Manufactured by Fuji Chemical Co., Ltd., TZA-206-200 (metal ion type: organic)
B: Manufactured by Fuji Chemical Co., Ltd., TZA301 (organic nitrogen sulfur type)
C: Manufactured by MIC Co., Ltd., PacificBeam MOLD/PBM-OK (diiodomethyl paratolyl sulfone)
D: Manufactured by Sinanen Zeomic Co., Ltd., Zeomic AJ (metal ion type: inorganic)

(4) Antibacterial test method (JIS Z 2801:2010)
In accordance with JIS Z 2801:2010, the antibacterial test process shown in FIG. 1 was performed according to the test method shown in FIG. 2.

(5) Mold resistance test method (JIS Z 2911:2018 Appendix A Test B method for plastic products)
The evaluation procedure consists of <1> preparation of agar medium, <2> preparation of spore suspension, <3> inoculation of mold onto a test piece, <4> culture, and <5> visual evaluation.
<1> Preparation of agar medium A glucose-added inorganic salt agar medium is aseptically dispensed into a petri dish so that the medium has a thickness of about 5 mm, and is left to cool to solidify.
<2> Preparation of spore suspension Mix equal amounts of single spore suspensions of each mold to obtain a mixed spore suspension. The suspension is prepared using a glucose-added inorganic salt solution. There are five mold species listed in Table 2.

<3> Inoculation of mold onto the test piece The test piece is cut into 40 mm squares and placed on the test agar medium as horizontally as possible. At this time, make sure that the test piece does not touch the wall of the Petri dish.
Spray an appropriate amount of the mixed spore suspension onto the surface of the test piece and agar medium, or drop it evenly with a pipette.
<4>Culture Cover the test agar medium and culture at 30°C and a humidity of 95% or higher for 4 weeks. At this time, be careful not to let water droplets fall on the surface of the test piece.
<5> Visual evaluation First, observe with the naked eye, and if necessary, observe with a stereomicroscope. The evaluation method for the state of mold growth is as shown in Table 3. Evaluation is performed with N=5, and the median value of the five evaluations obtained is used as the evaluation result.

The SIAA (Antibacterial Products Technology Council) states that the conditions for determining mold resistance are that processed products (mildew-resistant) have a label of 2 or less, blank (unprocessed products) have a label of 2 or more, and It is stipulated that the display of the product must be one level or more lower than the blank.
In addition, as in the antibacterial test, there are water resistance classification and light resistance classification as pretreatment, and if the product does not have mold resistance in both, it will not be recognized as having mold resistance by SIAA. Assuming an interior decorative board, the water resistance classification was 0 and the light resistance classification was 1.
The water resistance classification and light resistance classification are based on the following standards.
SIAA Test Method S08 Antibacterial Sustainability Test Method Water Resistance SIAA Test Method S09 Antibacterial Sustainability Test Method Light Resistance

The results are shown in Tables 4 and 5.

From Tables 4 and 5, it can be seen that Examples 1 to 5 have excellent antibacterial properties and sufficient antifungal properties. Furthermore, as in Comparative Examples 1 and 2, when the same antibacterial/fungal agent as in the example was added alone, antibacterial properties and antifungal properties could not be achieved at the same time. In addition, in Comparative Example 3, an organic antibacterial/fungal agent containing iodine is added, but although the iodine has a large effect on mold, no antibacterial property was observed, and the antibacterial property was not observed. The paint film had a tendency to yellow, and further yellowing was confirmed after the light resistance test, making it difficult to apply to decorative boards. In Comparative Example 4, silver ions and zinc ions were supported on zeolite, and although it had high antibacterial properties even when used alone, its mold resistance did not meet the standard.

The ceramic decorative laminate of the present invention has excellent antibacterial and fungicidal properties, as well as excellent nonflammability, strength, light resistance, etc. Therefore, antibacterial and fungicidal properties are required in schools, hospitals, food factories, kitchens, etc. It can be widely applied as an interior finishing material for buildings, etc.

Claims (2)

A ceramic decorative board having a colored layer and/or a clear layer containing an acrylic urethane resin on the outermost layer of at least one side of a ceramic substrate,
In the colored layer and/or clear layer, one or more selected from (a) a metal ion antibacterial/fungal agent and (b) an alkylene bisthiocyanate, a 3-isothiazolone compound, a sulfonamide compound, and a thiazole compound. Contains organic nitrogen sulfur-based antibacterial and fungicidal agents,
The total content of (a) and (b) is 1.5 to 3 parts by mass per 100 parts by mass of solid content in the acrylic urethane paint, and
characterized in that the content mass ratio (a/ b ) of (a) and (b) is 0.5 to 3 ;
Ceramic decorative board. The ceramic decorative board according to claim 1, wherein the metal ion-based antibacterial/fungal agent (a) is one or more selected from silver ion-based antibacterial/fungal agents and zinc ion-based antibacterial/fungal agents.