JP6842350B2 - Antiviral coating and veneer - Google Patents

Description

The present invention relates to an antiviral coating film and a decorative board having the coating film.

Traditionally, antibacterial agents and disinfectants have been used in buildings such as hospitals and nursing homes, equipment, medical equipment, etc. from the viewpoint of health and hygiene. Antibacterial and antiviral properties are expected for various building materials and equipment in a wide range of living environments. In response to such high social interest, antibacterial decorative boards were first marketed and their use as interior materials has become widespread, but nowadays, not only antibacterial but also infections such as influenza virus and norovirus are transmitted. There is an increasing need for interior materials that have sufficient antiviral properties against sex viruses.

As a technique for imparting antibacterial properties to interior materials, for example, a method of forming a surface coating layer of an interior wall covering material with a paint containing a silver-based antibacterial agent (Patent Document 1) is known, and is used for such applications. Antibacterial agents such as antibacterial zeolite (Patent Document 2) and silver oxide in which some of the ion-exchangeable metals of natural or synthetic zeolite are replaced with antibacterial metal ions such as silver, copper, and zinc. Inorganic antibacterial agents such as soluble glass (Patent Document 3) containing the above are used because they have a stable antibacterial action for a long period of time. Further, as a technique for antiviral paint, there is a method (Patent Document 4) in which a pulverized product obtained by firing a part of dolomite and then hydrating a part thereof is dispersed in a water-based resin paint, which is included in a silver-based antibacterial agent. It is also known that the silver ions have an effect on coronaviruses such as SARS virus (Patent Document 5).

Japanese Unexamined Patent Publication No. 2007-270589 Japanese Unexamined Patent Publication No. 60-181002 Japanese Unexamined Patent Publication No. 9-194756 JP-A-2007-106876 Re-table 2005-37296

However, antiviral properties have not been observed in interior wall coverings in which a silver-based antibacterial agent is simply contained in the coating film by the conventional method, and decorative boards using paints containing fired dolomite have also been used in recent years. It cannot be said that there is sufficient antiviral activity in light of the evaluation method of. Furthermore, when a silver-based antiviral agent containing silver ions, which is recognized to have antiviral properties, is added to form a coating film, the silver ions eluted from the antiviral agent become oxides, resulting in darkening of the coating film. May occur. This phenomenon was remarkable when the alkali resistance test was carried out in the evaluation of the coating film performance, and the occurrence of darkening at a level visible to the naked eye was observed on the surface of the coating film in contact with the sodium hydroxide aqueous solution. In general, bright light-colored tints are preferred for interior decorative boards, and the occurrence of such darkening causes noticeable discoloration, which causes a problem that it is not suitable in terms of appearance.
Therefore, an object of the present invention is to provide a coating film and a decorative board which are excellent in antiviral activity, do not generate darkening due to silver ions, and have an excellent aesthetic appearance.

The present inventor has examined and evaluated the antiviral activity of various inorganic antibacterial agents and antiviral agents when dispersed in a coating film, and found that most of the antibacterial agents show significant antiviral activity. However, even silver-based antiviral agents, which have been considered to be effective in the past, did not show the expected antiviral activity. Under such circumstances, surprisingly, the coating film to which a large amount of soluble glass containing zinc oxide was added showed excellent antiviral activity and darkened as seen in silver-based antibacterial agents. The present invention was completed by finding that it did not occur.

That is, the present invention provides the following [1] to [5].

[1] An antiviral coating film containing zinc-containing soluble glass in an amount of 1.4% by mass or more and 7.0% by mass or less in terms of ZnO.
[2] An antiviral coating film containing zinc-containing soluble glass in an amount of 3.5% by mass or more and 7.0% by mass or less in terms of ZnO.
[3] A decorative board having the coating film according to [1] or [2] on a decorative layer formed on at least one surface of a substrate.
[4] The decorative board according to [3], which has the coating film according to [1] or [2] on the outermost surface topcoat layer of the decorative layer.
[5] The decorative board according to [3] or [4], which is a decorative board for interior decoration.

Since the coating film of the present invention has excellent antiviral activity and does not cause darkening due to silver ions and exhibits an excellent aesthetic appearance, a decorative board represented by an interior building material having this is a decorative board. It is possible to effectively suppress the infectivity of viruses and the like in the space where the above is constructed.

The antiviral coating film of the present invention contains zinc-containing soluble glass in an amount of 1.4% by mass or more and 7.0% by mass or less, preferably 3.5% by mass or more and 7.0% by mass or less in terms of ZnO. It is a feature.

The zinc-containing soluble glass used for the anti-virus coating is a glass composition that gradually dissolves in water to release the zinc component. For example, phosphoric acid-based glass and boric acid-based glass have anti-virus properties. It is a glass in which ZnO is contained as an active ingredient and the composition is adjusted so as to have a controlled dissolution rate with respect to water.

The ZnO content of the zinc-containing soluble glass is 10% by mass or more and 50% by mass from the viewpoint of preventing deterioration of the coating performance due to excessive addition of the zinc-containing soluble glass and appropriately controlling the dissolution rate in water. % Or less is preferable, and 20% by mass or more and 40% by mass or less is more preferable. For example, the phosphoric acid-based glass contains P ₂ O ₅ , ZnO, alkaline earth metal oxides (MgO, CaO, etc.), alkali metal oxides (Na ₂ O, K ₂ O, etc.) as main components, and Al ₂ Those containing O ₃ , SiO _2, etc. can be used, and the boric acid-based glass contains B ₂ O ₃ , ZnO, SiO ₂ , alkali metal oxides (Na ₂ O, K ₂ O, etc.) as main components, and further. Those containing Al ₂ O ₃ and alkaline earth metal oxides (MgO, CaO, etc.) can be used. In addition, a small amount of Ag ₂ O may be contained as an auxiliary component other than zinc. In this case, the Ag ₂ O content is preferably 0.01 to 0.5 parts by mass with respect to 100 parts by mass of the zinc-containing soluble glass. If _{the content of Ag 2} O is less than 0.01 parts _{by mass, improvement of the antiviral effect by Ag 2} O cannot be expected, and if it exceeds 0.5 parts by mass, discoloration of the coating film due to silver oxide becomes conspicuous, which is preferable. Absent.

The zinc-containing soluble glass content in the coating film is 1.4% by mass or more and 7.0% by mass or less in terms of ZnO in the anti-virus coating film. If it is less than 1.4% by mass, sufficient antiviral activity cannot be obtained, and if it exceeds 7.0% by mass, the surface of the coating film becomes conspicuously rough, resulting in poor appearance and deterioration of coating film performance, which is not preferable. The preferable zinc-containing soluble glass content is 3.5% by mass or more and 7.0% by mass or less, more preferably 3.8% by mass or more and 7.0% by mass or less, and further preferably 5.0% by mass. It is 7.0% by mass or less.
Zinc-containing soluble glass is known to exhibit antibacterial properties by containing about 0.5 to 3.0% by mass of solid content in a composition such as a coating film, but exhibits antiviral activity. Is not known. Further, the stability when a zinc-containing soluble glass is contained in a coating film in a large amount of 10% by mass or more (3.0% by mass or more in terms of ZnO) as in the present invention is not known.

The average particle size of the zinc-containing soluble glass in the coating film is preferably 10.0 μm or less from the viewpoint of the uniformity of the coating film and the prevention of roughness on the surface of the coating film.

The paint on which the antiviral coating film of the present invention is based includes a radical oligomer-based paint, a monomer radical-based paint, an acrylic urethane resin paint, an acrylic resin paint, an epoxy resin paint, a polyurethane resin paint, a vinyl chloride resin paint, and a vinylidene chloride resin. Examples thereof include paints, acrylic silicone resin paints, and fluororesin paints.

Examples of the radical oligomer-based paint and the monomer radical-based paint are preferably epoxy-based acrylate, urethane-based acrylate, ester-based acrylate, acrylic-based acrylate, silicon-based acrylate, and unsaturated polyester-based paint, and specifically, epoxy acrylate and urethane acrylate. , Allyl-based unsaturated polyester such as phthalic acid diallyl ester, maleic acid-based unsaturated polyester by polycondensation of unsaturated dibasic acid such as maleic anhydride and fumaric acid with glycols, having carboxyl group and hydroxyl group as functional groups Polyester monoacrylate, polyester diacrylate obtained from acrylic acid, dibasic acid and divalent alcohol, polyester acrylate such as polyester polyacrylate obtained from trivalent or higher polyhydric alcohol and dibasic acid and acrylic acid, epoxy acrylate oligomer, Examples thereof include oligomers such as epoxy oligomers, acrylic polyethers, and polyether acrylates.

In the case of the coating film of the top coat layer, an acrylic urethane resin paint is preferable, and a two-component curable acrylic urethane resin paint is more preferable. In addition, acrylic resin paint, epoxy resin paint, polyurethane resin paint, vinyl chloride resin paint, vinylidene chloride resin paint, acrylic silicone resin paint, fluororesin paint, etc. are laminated in a single layer with the same paint, or It is preferable to laminate coatings of different paints to form a topcoat layer.

In addition, an inorganic dispersion filler can be contained in the coating film in order to uniformly disperse the zinc-containing soluble glass in the coating film. Examples of the inorganic dispersion filler include barium, silica, zeolite, kaolin, talc, zinc oxide and the like, and among them, barium or a salt thereof is particularly preferable. Examples of barium or a salt thereof include barium chloride, barium nitrate, barium sulfate, barium carbonate, barium hydroxide, barium peroxide, barium fluoride and the like, and barium sulfate is particularly preferable.
The average particle size of the inorganic dispersion filler is not particularly limited, but from the viewpoint of being easy to handle in various processing, an average particle size of 0.1 to 8 μm is preferable, but an average particle size of 0.8 to 1.8 μm is preferable. More preferred.
Further, as the dispersion medium, an organic solvent-based coating material using an ester-based solvent such as butyl acetate can also be used.

In order to form the antiviral coating film of the present invention, zinc-containing soluble glass may be dispersed in the paint, applied to the surface of a substrate such as a ceramic board, and cured. When the zinc-containing soluble glass is dispersed in the paint, a dispersion is prepared in advance by dispersing the zinc-containing soluble glass in an alcohol-based dispersion medium such as an ester-based dispersion medium or isopropyl alcohol at a high concentration, and this dispersion is mixed and dispersed in the paint. Is preferable. By using the dispersion liquid, the zinc-containing soluble glass can be easily uniformly dispersed in the paint, and the occurrence of aggregation and precipitation can be suppressed. The concentration of the dispersion is preferably 20 to 60% by mass, and a small amount of an inorganic filler can be added as a dispersion aid. Further, as the dispersion means, it is preferable to forcibly disperse using a homogenizer or the like in terms of uniformly and stably dispersing the zinc-containing soluble glass in the coating film and improving the finish.

The antiviral activity of the antiviral coating film of the present invention preferably has an antiviral activity value of 2.0 or more, and more preferably 3.0 or more. The antiviral activity value Mv was calculated from the following formula based on the virus infectious titer obtained by the evaluation test.
Virus infection value per test piece V = (virus infection value / mL) x (washout amount)
Antiviral activity value Mv = Log (V ₀ ) -Log (V ₁ )
Log (V ₀ ): Common logarithmic value of virus infectious titer V of antiviral-processed test piece _{Log (V 1): Common logarithmic value of virus infectious titer V of antiviral-processed test piece}

The antiviral coating film of the present invention can be applied to the surface of various building materials, equipment and the like, but it is preferably applied to a decorative board, particularly an interior decorative board. Therefore, according to the present invention, there is provided a decorative board characterized by having the antiviral coating film on the decorative layer formed on at least one surface of the substrate.

In the decorative board, the antiviral coating film may be formed on either the topcoat layer or the undercoat layer of the decorative layer, but the antiviral activity is obtained by forming the antiviral coating film on the topcoat layer, that is, the outermost surface topcoat layer of the decorative layer. It is preferable in that respect. Further, the decorative board is more preferably an interior decorative board, and further preferably a ceramic interior decorative board. The decorative board is preferably an interior non-combustible decorative board, particularly an interior non-combustible decorative board having a heat generation amount of 7.2 MJ or less for 20 minutes in the heat generation test specified in JIS A 5430 Annex JA. As the decorative board, plywood, resin board, various ceramic boards and the like can be applied, and among them, nonflammable boards such as fiber-reinforced cement board, gypsum board and fiber-mixed gypsum board are more preferable.

Next, the present invention will be described in more detail with reference to examples.

(1) Fiber reinforced cement board (board)
As the substrate, a calcium silicate board (corresponding to "Calcium silicate board type 2 0.8 calcium silicate board (0.8 FK)" in JIS A 5430 Table 1) was used.

(2) Paint The coating film was formed by using the following paint.
Impregnated sealer: Urethane sealer Undercoat paint: Acrylic epoxy UV curable paint (UV curable seal)
Topcoat paint: Two-component curable acrylic urethane paint (solid content concentration approx. 50%: light gray color)

Example 1
(A) Substrate adjustment The surface side of the substrate (the surface on which the coating film is to be applied) is polished with a belt sander to improve smoothness, and then an impregnated sealer is applied ^{at about 100 g / m 2 using a roll coater.} did.
^{(B) Formation of Undercoat Coating Film Approximately 150 g / m 2} of undercoat paint is applied to the surface coated with the impregnated sealer in (A) in two steps using a roll coater, and the undercoat paint is cured by ultraviolet irradiation. To form an undercoat coating film.
(C) Adjustment of Surface Coating Film Forming Paint As an antiviral agent, a dispersion liquid in which zinc-containing soluble glass powder having a ZnO content of about 30% by mass in solid content is dispersed in butyl acetate at a concentration of 50% by mass is prepared. This antiviral agent was added little by little to the topcoat paint and sufficiently dispersed using a homogenizer under the condition of 7,500 rpm to prepare a surface coating film forming paint. At this time, the antiviral agent was added so as to be 30% by mass (solid content) by external division with respect to 100 parts by mass of the solid content of the topcoat paint.
^{(D) Formation of surface coating film Approximately 100 g / m 2} of the surface coating film forming coating film (C) of (C) is applied onto the undercoat film formed in (B) above using a flow coater, and then a hot air dryer. A surface coating film layer was formed by heating, drying and curing in an atmosphere of 100 ° C. for 30 minutes to obtain a decorative plate.

Examples 2 to 6 and Comparative Examples 1 to 3
Cosmetics of Examples 2 to 6 and Comparative Examples 1 to 3 by the same steps as in Example 1 except that the amounts and types of antiviral agents and antibacterial agents added to the surface coating film forming paint were changed as shown in Table 1. I got a board.

Test Example 1 (influenza virus: with envelope)
The virus infectious titer against influenza virus was evaluated using the coating film surfaces of the decorative boards of Examples 1 to 6 and Comparative Examples 1 to 3 as test specimens.
Virus solution prepared to be about 10 ⁸ PFU / mL or more in MEM medium _{(Influenza A virus (H 3 N} 2): ATCC VR-1679) , and testing those diluted 10-fold with sterile distilled water virus It was made into a liquid. Each 5 cm square sample was inoculated with 0.4 mL of the test virus solution, covered with a 4 cm square PE film, adhered to the sample, and left at 25 ° C. for 24 hours. Then, 10 mL of the wash-out solution was added, and the virus was washed out from the sample by pipetting. The virus infectious titer in the washout solution was measured, and the common logarithmic value of the infectious titer per sample was calculated. The comparative control was a decorative board (unprocessed) prepared in the same manner as in Example 1 except that no antiviral agent and antibacterial agent were added, and measurements were taken 24 hours later and immediately after inoculation. As the wash-out solution, SCDLP medium was used. The virus infectivity titer was measured by the Plaque assay. (Reference standards: ISO18184, JIS L 1922, JIS Z 2801)

The results are shown in Table 2.

From Table 2, the silver-based antibacterial agent and the silver-based antibacterial-antiviral agent against influenza virus showed almost no antiviral activity despite the high concentration of addition, whereas they contained zinc. The coating film to which the sex glass was added showed excellent antiviral activity of Mv = 4.0 or more. According to the evaluation criteria of JIS L 1922, when the antiviral activity value Mv is 2.0 or more, it is evaluated as having antiviral property, and when it is 3.0 or more, it is evaluated as having sufficient antiviral property.

Test Example 2 (feline calicivirus (norovirus substitute): no envelope)
Similar to Test Example 1, the virus infectious titer against feline calicivirus (norovirus substitute) was evaluated.
Virus solution prepared to be about 10 ⁸ PFU / mL or more in MEM medium: a (Feline calicivirus Feline calicivirus ATCC VR-782), was a material obtained by diluting 10-fold with sterilized distilled water as a test virus solution. Each 5 cm square sample was inoculated with 0.4 mL of the test virus solution, covered with a 4 cm square PE film, adhered to the sample, and left at 25 ° C. for 24 hours. Then, 10 mL of the wash-out solution was added, and the virus was washed out from the sample by pipetting. The virus infectious titer in the washout solution was measured, and the common logarithmic value of the infectious titer per sample was calculated. The comparative control was "raw", and measurements were taken 24 hours later and immediately after inoculation. As the wash-out solution, SCDLP medium to which serum was added so as to have a final concentration of 10% was used. The virus infectivity titer was measured by the Plaque assay. (Reference standards: ISO18184, JIS L 1922, JIS Z 2801)

The results are shown in Table 3.

From Table 3, silver-based antibacterial agents and silver-based antibacterial-antiviral agents showed almost no antiviral activity against feline calicivirus, whereas zinc-containing soluble glass was added in an amount of 15% by mass in solid content. In Example 4, Mv = 2.8, indicating effective antiviral activity. Further, in Examples 1 to 3 in which zinc-containing soluble glass was added in an amount of 20% by mass or more in terms of solid content, the Mv value greatly exceeded 3.0, and excellent antiviral activity was observed. Since feline calicivirus does not have an envelope like norovirus, it is said that it is less likely to be inactivated than influenza virus having an envelope. Based on the test results of Examples 1 to 6, the relationship between the ZnO content in the coating film and the antiviral activity value Mv is shown in FIG. Effective antiviral activity can be obtained in the range of ZnO content in which the value of antiviral activity value Mv is 2.0 or more, and this range of ZnO content can be said to be a preferable range.

A sodium hydroxide aqueous solution having a mass fraction of 5% was added dropwise to the coating films of the decorative boards of Examples 1 to 6 and Comparative Examples 1 to 3, and the discolored state after 24 hours was observed. A light gray color was used as the base topcoat to make it easier to observe the presence or absence of discoloration of the coating film. As a result, in Comparative Examples 1 to 3 to which the silver-based antibacterial agent was added, conspicuous darkening occurred in the portion in contact with the sodium hydroxide aqueous solution. On the other hand, in Examples 1 to 6 using the zinc-containing soluble glass, although the color was slightly discolored to white, the influence was slight, and the level was not a problem in use as an interior material.

Further, in Examples 1 to 6, there was no problem in other coating film performance, and the finish was beautiful in appearance, but in Comparative Example 3 in which the antibacterial agent was added as a powder to the topcoat paint, the antibacterial effect was obtained. The dispersion of the agent was poor, the surface of the obtained coating film was very rough, and the finish was not suitable as a decorative board from the viewpoint of aesthetics.

Furthermore, as a result of evaluating the nonflammability of the decorative boards of Examples 1 to 6 by the heat generation test specified in JIS A 5430 Annex JA, the calorific value for 20 minutes was in the range of 5.0 to 6.7 MJ, and the non-combustible decorative boards. It was confirmed that it has sufficient performance.

As described above, the coating film of the present invention has excellent antiviral activity and does not cause darkening due to silver ions and exhibits an excellent aesthetic appearance. Can be suppressed.

Claims (5)

An antiviral coating film containing zinc-containing soluble glass in an amount of 1.4% by mass or more and 7.0% by mass or less in terms of ZnO (excluding cases containing 10 to 50 mol% of copper-containing oxide) . The antiviral coating film according to claim 1, wherein the content of the zinc-containing soluble glass is 3.5% by mass or more and 7.0% by mass or less in terms of ZnO. A decorative board according to claim 1 or 2, wherein the decorative layer formed on at least one surface of the substrate has the coating film according to claim 1. The decorative board according to claim 3, wherein the outermost surface topcoat layer of the decorative layer has the coating film according to claim 1 or 2. The decorative board according to claim 3 or 4, which is a decorative board for interior decoration.