JP6030796B1 - Antiviral decorative board - Google Patents

Abstract

Disclosed is a decorative board capable of sufficiently exhibiting the function of a visible light responsive photocatalyst while maintaining good design properties. A visible light reflecting layer laminated on one or both surfaces of the substrate, an oxidation resistant resin layer made of an oxidation resistant resin disposed on the visible light reflecting layer, and the oxidation resistant material. A decorative board comprising a visible light responsive photocatalyst disposed on a conductive resin layer, wherein the visible light reflective layer has a reflectance of light of 430 to 500 nm in light of 60% or more. [Selection] Figure 1

Description

The present invention relates to an antiviral decorative board.

Conventionally, a decorative board provided with functionalities such as antifouling properties and antibacterial properties by adding or applying a visible light responsive photocatalyst such as a photocatalyst to a decorative board such as a melamine decorative board has been provided.

Patent Document 1 discloses an antifouling decorative board obtained by laminating a silicone resin-impregnated surface paper on a decorative paper for a decorative board, applying a photocatalytic coating agent after hot pressing.

Patent Document 2 discloses a technique for supporting a photocatalyst on a fluororesin as a binder.

JP 2003-276117 A Japanese Patent Laid-Open No. 07-171408

However, in the decorative board described in Patent Document 1, the design of the decorative board may be impaired by visualizing the functional material fixed in the vicinity of the surface. Therefore, the decorative board in which the visible light responsive photocatalyst is fixed in the vicinity of the surface has a problem that it is difficult to achieve both design and functionality.
Further, in the technique described in Patent Document 2, since the silicone resin and the fluororesin are devitrified due to turbidity, the design property of the pattern layer is lowered, and the reflectance of visible light is low due to scattering due to turbidity. There has been a problem that the function of the visible light responsive photocatalyst cannot be fully exploited.

This invention is made | formed in view of such a problem, and it aims at providing the decorative board which can fully exhibit the function of a visible light response type photocatalyst, maintaining a good design property. .

The decorative board of the present invention includes a substrate, a visible light reflecting layer laminated on one or both surfaces of the substrate,
The oxidation-resistant resin layer made of an oxidation-resistant resin disposed on the visible light reflection layer, and a visible light responsive photocatalyst disposed on the oxidation-resistant resin layer, the visible light reflection layer, The reflectance of light having a wavelength of 430 to 500 nm is 60% or more.

In the decorative board of the present invention, since the visible light responsive photocatalyst is disposed on the oxidation resistant resin layer, the oxidation resistant resin is hardly deteriorated by the action of the visible light responsive photocatalyst.
Furthermore, since a visible light reflecting layer having a reflectance of 60% or more of light having a wavelength of 430 to 500 nm is provided under the oxidation resistant resin layer on which the visible light responsive photocatalyst is disposed, once oxidation resistance is provided. Of the visible light that has passed through the resin layer, the wavelength component for which the visible light responsive photocatalyst is likely to be active is easily reflected, and the visible light responsive photocatalyst is not only reflected from the upper surface of the decorative board but also from the lower side by the reflected visible light. Can be activated. Therefore, the activity of the visible light responsive photocatalyst can be further increased, and excellent antibacterial and antiviral properties can be exhibited.

In the present specification, the visible light reflecting layer refers to a layer having a reflectance of light having a wavelength of 430 to 500 nm of 60% or more.
In the case of employing a composite in which patterned paper is impregnated and cured as the visible light reflecting layer, the reflectance is in a state where the resin is impregnated and cured, and not the reflectance of the patterned paper itself.
For the measurement of the visible light reflectance, the reflectance is measured in the range of at least 400 to 600 nm, a graph showing the relationship between the measurement wavelength and the reflectance as shown in FIG. 2 is drawn, and the reflectance is in the range of 430 to 500 nm. If it is 60% or more, it is interpreted that the requirement on reflectance is satisfied.
When the reflectance is measured every 5 nm or 10 nm, adjacent measurement points are connected to form a graph of measurement wavelength and reflectance.
The reflectance can also be measured when the patterned paper is impregnated with resin and cured, and after the visible light reflecting layer is exposed by polishing or peeling off the oxidation-resistant resin layer. It can be measured using a spectrocolorimeter.
Polishing can remove the oxidation-resistant resin layer by wet polishing with a diamond abrasive, a silicon carbide abrasive, an alumina abrasive or the like.

In the decorative board of the present invention, the visible light reflection layer is preferably a composite made of a pattern paper and a resin containing at least one selected from the group consisting of a white pigment, a white dye, and a fluorescent brightening agent. .
When the visible light reflection layer is a composite composed of a pattern paper and a resin whitened with at least one selected from the group consisting of a white pigment, a white dye, and a fluorescent brightening agent, the wavelength is 430 to 500 nm. Light can be sufficiently reflected, and the visible light responsive photocatalyst can be sufficiently activated.

In the decorative board of the present invention, the white pigment is preferably at least one selected from the group consisting of lead white, titanium oxide, zinc white, calcium carbonate, talc, silica and alumina.
This is because these white pigments easily reflect light having a wavelength of 430 to 500 nm, and a whitening layer can be formed on the surface of the pattern paper by printing or printing on the paper.

In the decorative board of the present invention, the fluorescent whitening agent is preferably at least one selected from the group consisting of a diaminostilbene type whitening agent, umbelliferone and esculin. These fluorescent brighteners can reflect light from 430 to 500 nm. Furthermore, these fluorescent brighteners absorb ultraviolet rays and exhibit fluorescence of 430 to 500 nm. Therefore, the activity of the visible light responsive photocatalyst can be further increased.
These white pigments, white dyes and fluorescent brighteners may be formed on pattern paper, impregnated, or printed on the surface by gravure printing or the like.

In the decorative board of the present invention, it is desirable that the visible light reflection layer is a composite made of a pattern paper containing glossy particles and a resin.

In the decorative board of the present invention, the glossy particles are preferably metal particles or mica particles. This is because these glossy particles can easily reflect light of 430 to 500 nm, and can form a gloss layer on the surface of the patterned paper by being printed on paper or printing.
The metal particles are preferably at least one selected from the group consisting of gold, silver, copper, aluminum, chromium, and stainless steel. Since the metal particles made of these metals are excellent in corrosion resistance, it is possible to extend the life of the decorative board when used for the decorative board.

In the decorative board of the present invention, the visible light reflection layer preferably includes a metal layer.
When the visible light reflecting layer includes a metal layer, light having a wavelength of 430 to 500 nm can be sufficiently reflected, and the visible light responsive photocatalyst can be sufficiently activated.

In the decorative board of the present invention, the oxidation-resistant resin is preferably made of a silicone resin or a fluororesin.
Silicone resin or fluororesin is excellent in oxidation resistance and is suitable as a material constituting the oxidation resistant resin layer.

In the decorative board of the present invention, since the visible light responsive photocatalyst is disposed on the oxidation resistant resin layer, the oxidation resistant resin is hardly deteriorated by the action of the visible light responsive photocatalyst.
Furthermore, since a visible light reflecting layer having a reflectance of 60% or more of light having a wavelength of 430 to 500 nm is provided under the oxidation resistant resin layer on which the visible light responsive photocatalyst is disposed, once oxidation resistance is provided. Of the visible light that has passed through the resin layer, the wavelength component in which the visible light responsive photocatalyst is likely to be active is easily reflected, and the visible light responsive photocatalyst can be activated again by the reflected light. Therefore, the function of the visible light responsive photocatalyst can be fully exhibited, and excellent antibacterial and antiviral properties can be obtained.

FIG. 1 is a schematic cross-sectional view schematically showing a decorative board according to an embodiment of the present invention. FIG. 2 is a reflection spectrum of the visible light reflection layer in Example 1 and Comparative Example 1.

Hereinafter, the decorative board of the present invention will be described in detail.
FIG. 1 is a schematic cross-sectional view schematically showing a decorative board according to an embodiment of the present invention.

A decorative board 1 of the present invention includes a substrate 10, a visible light reflecting layer 11 laminated on the surface of the substrate 10, an oxidation resistant resin layer 12 disposed on the visible light reflecting layer 11, and an oxidation resistant resin. The visible light responsive photocatalyst 13 disposed on the layer 12 has a structure disposed. As shown in FIG. 1, visible light (visible light incident on the decorative board in FIG. 1 is indicated by a solid arrow) is reflected by the visible light reflecting layer 11, and the lower surface side of the visible light responsive photocatalyst 13 (the substrate 10). (In FIG. 1, visible light reflected by the visible light reflecting layer 11 is indicated by a broken-line arrow).

The visible light reflection layer constituting the decorative board of the present invention has a reflectance of light having a wavelength of 430 to 500 nm of 60% or more, more preferably 70% or more, and further preferably 80% or more.
When the reflectance of light having a wavelength of the visible light reflecting layer of 430 to 500 nm is 60% or more, among visible light that has once passed through the visible light responsive photocatalyst, there is a wavelength component in which the visible light responsive photocatalyst easily exhibits activity. The visible light responsive photocatalyst can be activated again by the reflected light.
The method for adjusting the reflectance of light having a wavelength of 430 to 500 nm in the visible light reflecting layer is not particularly limited, and examples thereof include a method for adjusting the color of the pattern paper constituting the visible light reflecting layer.

The light reflectance of the visible light reflecting layer can be measured by irradiating light toward the visible light reflecting layer and measuring the reflected light. Specifically, a spectrocolorimeter [suga It can be measured using SC-P] manufactured by Tester Co., Ltd.
The spectral colorimetry method is a (Sa), the effective wavelength width is 5 nm, the wavelength interval used for calculating the tristimulus value is 5 nm (W5), and the color matching function type is X ₁₀ Y ₁₀ Z ₁₀ color system. (CIE1964 color system), the measurement illuminant is the standard illuminant D65, and the geometric condition of irradiation and light reception is the geometric condition c (de: 8 °). The measurement hole is φ30 mm.
When the color of the pattern paper is no pattern and a single color, the measurement is performed at one point selected at random. On the other hand, when a pattern exists in the color of the pattern paper, the reflectance is measured at one point selected at random for each pattern (color) region. For example, in the case of a white and black checkered flag pattern, the reflectance is measured for one point in the white region and one point in the black region. If the reflectance of light having a wavelength in the white region of 430 to 500 nm is 60% or more, the effect of the present invention is exhibited in that region. Therefore, the reflectance of light having a wavelength of 430 to 500 nm in the black region is 60. Even if it is less than%, it is interpreted as utilizing the present invention.
Note that the reflectance of light having a wavelength of 430 to 500 nm is 60% or more means that the reflectance in the wavelength region of 430 to 500 nm is all 60% or more in the reflection spectrum measured under the above measurement conditions. means.
That is, in the case where there is a region where the reflectance is less than 60% in any region in the wavelength range of 430 to 500 nm, even if the reflectance in all regions other than the above region is 60% or more, It cannot be said that the reflectance of light at 430 to 500 nm is 60% or more.
The same applies when the reflectance is 70% or more and 80% or more.

The substrate used for the decorative board of the present invention is not particularly limited, and non-combustible base materials such as core paper and magnesia cement generally used for decorative boards, gypsum boards, metal plates, etc. may be used. it can. The core paper may be a single core or a laminate in which a plurality of core papers are stacked. The number of core papers is not particularly limited, but can be 1 to 20 sheets. As the core paper, for example, aluminum hydroxide paper can be used. As the core paper, kraft paper impregnated with thermosetting resins such as phenol resin, unsaturated polyester resin, and melamine resin can be used. Moreover, a core paper and a magnesia cement incombustible base material can be laminated to form a substrate.

The magnesia cement incombustible base material can be used as a substrate by using it alone or by laminating it at the center of the core paper. The magnesia cement incombustible base material is manufactured by mixing magnesium oxide (MgO) and magnesium chloride (MgCl ₂ ), adding aggregate and water, kneading, and forming into a plate shape. As the aggregate, inorganic fibers such as rock wool and glass wool, and organic fibers such as wood chips and pulp can be used. Moreover, in order to raise the intensity | strength of a magnesia cement incombustible base material, the glass fiber layer formed in mesh shape etc. can be provided as an intermediate | middle layer.

The method of forming the visible light reflecting layer on the substrate surface composed of a plurality of or a single core paper and / or magnesia cement incombustible substrate is not particularly limited, and can be performed by a general method. For example, it is possible to use a method in which a pattern paper with adjusted color is impregnated with melamine resin or the like (hereinafter also referred to as melamine resin-impregnated paper) is laminated on one or both sides of a substrate and hot-pressed. When the above method is used, the melamine resin or the like impregnated in the pattern paper penetrates into the core paper, where the curing reaction proceeds, and the adhesive strength of the pattern paper to the core paper is developed.
As the pattern paper adjusted in color, gravure printing, ink jet printing, silk screen printing at least one substance selected from the group consisting of white pigment, white dye or fluorescent whitening agent (also called whitening agent) Pattern paper printed with the above, pattern paper in which the whitening agent is incorporated, or pattern paper whose color is adjusted to white by impregnating the whitening agent.
At this time, when the color of the pattern paper is adjusted by printing, the visible light reflecting layer is formed on the substrate by arranging the printed surface (the color-adjusted surface) to be on the outside (opposite side of the substrate). Will be.
In the present invention, it is desirable to uniformly include a whitening agent on the entire surface of the pattern paper. That is, it is desirable that the whitening agent is printed uniformly on the entire surface of the pattern paper so as to be a single color without any pattern, or is uniformly engraved on the entire pattern paper, or uniformly impregnated on the pattern paper. . This is because the pattern paper formed in this manner reflects visible light uniformly, so that the visible light responsive photocatalyst can be sufficiently activated.

Examples of the resin that can be used for the visible light reflecting layer constituting the decorative board of the present invention include melamine resin, diallyl phthalate (DAP) resin, unsaturated polyester resin, olefin resin, vinyl chloride resin, acrylic resin, epoxy resin, and urethane. Resins, phenol resins, silicone resins, guanamine resins and the like can be mentioned. Among these, it is desirable to use melamine resin, diallyl phthalate (DAP) resin and unsaturated polyester resin.

Melamine resin is a resin with improved dimensional stability and toughness without impairing optical and visual properties such as translucency. As the melamine resin, known resins can be adopted as long as they are resins having melamine and its derivatives as monomers. The melamine resin may be a resin composed of a single monomer or a copolymer composed of a plurality of monomers. Examples of the melamine derivative include derivatives having a functional group such as an alkoxymethyl group such as an imino group, a methylol group, a methoxymethyl group, or a butoxymethyl group. Further, a compound obtained by reacting a lower alcohol with a melamine derivative having a methylol group and partially or completely etherified can be used as a monomer. Monomethylol melamine, dimethylol melamine, trimethylol melamine, tetramethylol melamine, pentamethylol melamine, hexamethylol melamine and other derivatives having a methylol group (hereinafter referred to as “methylolated melamine”) are copolymerized with melamine as a crosslinking agent. Can be used.

The melamine resin-impregnated paper is prepared by impregnating a melamine resin with a predetermined impregnation rate on a pattern paper with adjusted color, followed by heating and drying. The pattern paper can be impregnated with the melamine resin by immersing the pattern paper in a melamine resin-containing solution using, for example, an aqueous formaldehyde solution as a solvent. Further, in order to impart bending workability to the melamine resin-impregnated paper, it is possible to impregnate a solution containing a plasticizer together with the melamine resin. As the plasticizer, for example, ε-caprolactam, acetoguanamine, p-toluenesulfonic acid amide, urea and the like can be used. For example, titanium paper is used as the pattern paper. The basis weight of the pattern paper can be set to 80 to 150 g / m ² in consideration of the thickness and weight of the pattern paper. The temperature for heating and drying can be set to 100 to 150 ° C. in order to firmly fix the melamine resin to the pattern paper.
When adjusting the color white is the whiteness measured as defined in JIS Z 8715 (1999), it is desirable whiteness index _{W 10} is 60 or more, more desirably 70 or more.

The visible light reflecting layer constituting the decorative board of the present invention is preferably a composite composed of patterned paper containing glossy particles and a resin.
That is, it is desirable to use a pattern paper containing glossy particles as the pattern paper whose color is adjusted.
As the glossy particles, metal particles or mica particles are desirable.
Specific examples of patterned paper containing glossy particles include inks containing glossy particles printed on the surface of patterned paper, papers with glossy particles imprinted on the pattern paper, and gloss on the surface of patterned paper. The thing which sprayed the property particle etc. are mentioned.
The reflectance of the visible light reflecting layer can be adjusted by adjusting the color of the pattern paper with the glossy particles.
In the present invention, it is desirable to uniformly include the glossy particles on the entire surface of the pattern paper. That is, glossy particles are printed uniformly on the entire surface of the pattern paper so that there is no pattern and a single color, or the glossy particles are embedded on the entire surface of the pattern paper, or the glossy particles are applied to the pattern paper. It is desirable to uniformly impregnate the material. This is because visible light is uniformly reflected and the visible light responsive photocatalyst can be sufficiently activated.
In addition, when printing on the surface of a pattern paper with the ink containing a glossy particle, the printing method is not specifically limited, Gravure printing, inkjet printing, silk screen printing, etc. can be used. Note that it is desirable that the printing is performed uniformly on the entire surface of the pattern paper which is the front side.

The ink for adjusting the color of the pattern paper includes at least one solvent selected from water, an anti-drying agent (glycerin, glycol, etc.), and a penetrating agent (alcohol, glycol ether, etc.). It is desirable that the blended resin is mixed with a white pigment or glossy particles.

The white pigment is preferably composed of at least one selected from the group consisting of lead white, titanium oxide, zinc white, calcium carbonate, talc, silica and alumina.
The fluorescent whitening agent is preferably at least one selected from the group consisting of a diaminostilbene type whitening agent, umbelliferone and esculin.
As the glossy particles, metal particles and mica particles can be used.
The metal particles are preferably composed of at least one selected from the group consisting of gold, silver, copper, aluminum, chromium, and stainless steel.
The average particle diameter of the white pigment and the glossy particles is not particularly limited, but is preferably 0.1 to 10 μm.

The pattern paper used for the visible light reflecting layer constituting the decorative board of the present invention is preferably titanium paper containing titanium oxide, and more preferably titanium paper containing 5 to 20% by weight of titanium oxide.
If the pattern paper contains titanium oxide, the ink tends to adhere to the surface of the pattern paper.

The visible light reflecting layer constituting the decorative board of the present invention preferably includes a metal layer.
When the visible light reflecting layer includes a metal layer, light having a wavelength of 430 to 500 nm can be sufficiently reflected, and the visible light responsive photocatalyst can be sufficiently activated.
When the visible light reflecting layer includes a metal layer, the visible light reflecting layer may be composed only of a metal foil that becomes the metal layer, or may be a composite of a patterned paper and a resin provided with the metal layer.
As a structure of a decorative board in case a visible light reflection layer consists only of a metal layer, what provided the metal layer on the base material and provided the oxidation resistant resin layer on this metal layer is mentioned.
Moreover, as a pattern paper provided with the metal layer, the thing which vapor-deposited the metal film on the surface of the pattern paper, the thing which backed the pattern paper on the metal foil, etc. are mentioned.
As a metal which comprises a metal layer, the thing similar to the metal which comprises a metal particle can be used suitably.

In the decorative board of the present invention, an oxidation resistant resin layer is disposed on the visible light reflection layer.
The oxidation-resistant resin layer may be one obtained by impregnating an oxidation-resistant resin into overlay paper or the like, or may be composed of a film of an oxidation-resistant resin layer.
The oxidation resistant resin is not particularly limited as long as it is not easily deteriorated by the action of the visible light responsive photocatalyst, that is, a resin having oxidation resistance, but either a silicone resin or a fluororesin is desirable.
Silicone resin and fluororesin usually have low visible light reflectivity due to scattering due to turbidity, and the function of the visible light responsive photocatalyst cannot be fully exploited. However, in the decorative board of the present invention, the visible light responsive photocatalyst Since the visible light reflecting layer is provided below the oxidation resistant resin layer in which is disposed, the function of the visible light responsive photocatalyst can be sufficiently brought out.

The overlay paper constituting the oxidation-resistant resin layer preferably has an ash content of 0.1 to 5% by weight. When the ash content exceeds 5% by weight, the visible light permeability of the oxidation-resistant resin layer is lowered, and the function of the visible light responsive photocatalyst may be lowered.

As the silicone resin constituting the oxidation resistant resin layer, for example, a silicone resin, a modified silicone oil or the like can be used. As the modified silicone oil, a silicone oil having one or more functional groups in the molecule can be used. The position at which the functional group is introduced is not particularly limited, and the functional group may be introduced at any position of one end, both ends or side chains of the polysiloxane main chain. Moreover, as a functional group, a hydroxyl group, an amino group, a methoxy group, a hydrazino group, an epoxy group, a methacryl group, a carboxyl group, a carbinol group etc. can be introduce | transduced, for example.
As the fluororesin, a fluororesin emulsion can be used.

In the decorative board of the present invention, the oxidation-resistant resin layer may contain a silane coupling agent.
As the silane coupling agent, for example, those having a functional group such as vinyl group, propenyl group, butadienyl group, styryl group, acryloyl group, methacryloxy group, amino group, mercapto group, and isocyanate group are desirable. Examples of the silane coupling agent include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, allyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 2- (3,4 -Epoxycyclohexyl) ethyltrimethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane , 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, diallyldimethylsilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, etc. It is.

In the decorative board of the present invention, a visible light responsive photocatalyst is disposed on the oxidation resistant resin layer.
The visible light responsive photocatalyst is preferably a platinum-supported titania catalyst, a copper-supported titania catalyst, an iron-supported titania catalyst, a nitrogen-doped titania catalyst, a sulfur-doped titania catalyst, a carbon-doped titania catalyst, or a tungsten oxide, and a copper-supported titania. More preferably it is a catalyst. Examples of the copper-supported titania catalyst include anatase-type titanium oxide containing copper in a range of CuO / TiO ₂ (weight% ratio) = 1.0 to 3.5 described in JP-A-2006-232729. Photocatalyst composition in which cuprous oxide (copper oxide (I): Cu ₂ O) and titanium oxide described in Japanese Unexamined Patent Publication No. 2012-210557 are combined, and monovalent copper described in Japanese Patent Application Laid-Open No. 2013-166705 Titanium oxide carrying a mixture containing a compound and a divalent copper compound on the surface, and copper containing titanium oxide containing crystalline rutile-type titanium oxide and divalent copper compound described in International Publication No. 2013/094573 And titanium-containing compositions.

In the decorative board of the present invention, it is desirable that an aggregate in which primary particles of the visible light responsive photocatalyst are aggregated is supported on the oxidation resistant resin layer. If the aggregates of primary particles of visible light responsive photocatalysts are supported on the oxidation-resistant resin layer, bacteria and viruses are trapped between the primary particles of visible light responsive photocatalysts. Easy to deactivate. In particular, when a fluid such as an airflow or liquid containing splashed bacteria or viruses comes in contact with the surface of the decorative board, these splashed bacteria or viruses have kinetic energy, so they are sufficiently responsive to visible light responsive photocatalysts. In the decorative board in which the aggregates of the primary particles of the visible light responsive photocatalyst are supported on the oxidation-resistant resin layer, the visible light responsive photocatalyst is detached from the surface of the decorative board. Since the aggregates are supported on the oxidation-resistant resin layer, bacteria and viruses can be trapped between the primary particles of the visible light responsive photocatalyst to ensure sufficient reaction time. Compared to the case where the primary particles are singly supported on the oxidation-resistant resin layer, the antibacterial and antiviral effects are excellent.
Furthermore, when a photocatalyst (titanium oxide) is used as a visible light responsive photocatalyst, the aggregate of the photocatalyst is hydrophilic, and liquids such as water containing bacteria and viruses are sucked into the gaps between the photocatalyst particles by capillary action. This makes it easier to inactivate bacteria and viruses in the liquid.
Further, by aggregating the visible light responsive photocatalyst, whitening can be easily suppressed without reducing the function. For this reason, whitening can be prevented even if the amount of the visible light responsive photocatalyst is increased or the thickness of the visible light responsive photocatalyst carrying layer is increased.
The average particle diameter of the primary particles is desirably 10 nm to 200 nm. The average particle diameter of the aggregate in which the primary particles are aggregated is desirably 50 nm to 1000 nm. The average particle size is determined by measuring the particle size (diameter) of any 10 primary particles or aggregated particles from an image taken with an electron microscope.

In the decorative board of the present invention, the visible light responsive photocatalyst carrying amount (abundance) is preferably 0.02 to 2.20 g / m ² . When the visible light responsive photocatalyst is an aggregate, whitening does not occur as long as the supported amount is 2.20 g / m ² or less. Moreover, if it is 0.02 g / m < ² > or more, a virus can be inactivated.
The loading amount of the visible light responsive photocatalyst is more preferably 0.02 to 0.21 g / m ² . This is because the virus can be deactivated and whitening can be prevented within this range without aggregating the visible light responsive photocatalyst.
In addition, the amount (abundance) of the visible light responsive photocatalyst present on the oxidation-resistant resin layer is obtained by eluting the visible light responsive photocatalyst from the surface of the decorative board using hot concentrated sulfuric acid or a dissolved alkali salt. It can be calculated by analyzing the obtained eluate by ICP (inductively coupled plasma) emission spectroscopy.

In the decorative board of the present invention, the ceramic particles may be exposed on the oxidation-resistant resin layer, and the visible light responsive photocatalyst may be supported on the exposed surface of the ceramic particles.
When the visible light responsive photocatalyst is supported on the exposed surface of the ceramic particles, the visible light responsive photocatalyst does not directly contact the oxidation resistant resin layer. Therefore, it is possible to prevent deterioration of the oxidation-resistant resin layer due to the visible light-responsive photocatalyst, and to prevent the visible-light-responsive photocatalyst from falling off due to discoloration of the oxidation-resistant resin layer or deterioration of the oxidation-resistant resin layer. can do. In addition, when the visible light responsive photocatalyst is supported on the exposed surface of the ceramic particles, the visible light responsive photocatalyst is not buried in the oxidation-resistant resin layer, and is exposed on the decorative plate surface. The original functions as a visible light responsive photocatalyst such as antibacterial property and antiviral property can be exhibited, and the effect can be maintained for a long time.
The ceramic particles are not particularly limited as long as the particles have an isoelectric point higher than that of the visible light responsive photocatalyst and can carry the visible light responsive photocatalyst, but are aluminum oxide-containing particles. Is desirable. Specifically, it is desirable to use particles made of either alumina or strontium aluminate as the ceramic particles.

In the decorative board of the present invention, the average particle size of the ceramic particles is preferably 0.1 to 55 μm, and more preferably 0.5 to 5 μm. If the average particle diameter of the ceramic particles is less than 0.1 μm, the ceramic particles tend to be embedded in the oxidation-resistant resin layer, and the visible light responsive photocatalyst tends to be less likely to be supported on the ceramic particles. When the diameter exceeds 55 μm, ceramic particles fall off or irregularities are formed in the oxidation-resistant resin layer, so that there is a tendency for defects in the appearance and design properties of the decorative board. When the average particle diameter of the ceramic particles is 0.5 to 5 μm, the functionality as a visible light responsive photocatalyst is exhibited, and there is no problem in the appearance and design of the decorative board.
The ceramic particles are placed on the surface of the film, and the ceramic particles are placed on the oxidation-resistant resin layer so that the ceramic particles are in contact with the surface of the oxidation-resistant resin layer. Can be transferred and carried on the surface of the oxidation-resistant resin layer.
The surface of the film is preferably roughened so that the arithmetic average roughness Ra specified in JIS B 0601 (2013) is about 0.01 to 100 μm.

The decorative board of the present invention may have a dried inorganic sol or a dried organic sol on the surface of the oxidation-resistant resin layer. By fixing the visible light responsive photocatalyst through the dried inorganic sol or the dried organic sol, the visible responsive photocatalyst can be more firmly fixed. As the inorganic sol, silica sol, alumina sol, silica-alumina sol, titania sol and the like can be used, and it is desirable to use silica sol. As the organic sol, a thermosetting resin such as a silicone resin can be used, and a fluororesin can also be used. Among these, it is desirable to use a silicone resin. By using silica or silicone resin as the sol, the adhesion between the visible light responsive photocatalyst and the oxidation-resistant resin layer can be improved, the falling off of the visible light responsive photocatalyst is suppressed, and the functionality is maintained. .

In the decorative board of the present invention, a titanium peroxide layer may be formed on the oxidation-resistant resin layer, and a visible light responsive photocatalyst may be supported on the titanium peroxide layer. The visible light responsive photocatalyst is more preferably an aggregate in which a plurality of particles are aggregated.
When the titanium peroxide layer is formed on the oxidation resistant resin layer, the visible light responsive photocatalyst does not directly contact the oxidation resistant resin layer as in the case where the ceramic particles are provided. Therefore, it is possible to prevent deterioration of the oxidation-resistant resin layer due to the visible light-responsive photocatalyst, and to prevent the visible-light-responsive photocatalyst from falling off due to discoloration of the oxidation-resistant resin layer or deterioration of the oxidation-resistant resin layer. can do.

In the decorative board of the present invention, the titanium peroxide constituting the titanium peroxide layer is preferably amorphous titanium peroxide. Amorphous titanium peroxide is in an amorphous state at room temperature and is not crystallized in anatase titanium oxide. When a titanium peroxide layer is formed using a sol containing amorphous titanium peroxide, it is possible to produce a uniform and flat thin film with excellent adhesion, high film formability, and a dried film. It has an excellent property that it does not dissolve in water.

In the decorative board of the present invention, the thickness of the titanium peroxide layer is preferably 0.1 to 500 μm. By setting the thickness of the titanium peroxide layer within the above range, the visible light responsive photocatalyst can be brought into close contact with the oxidation resistant resin layer, and the characteristics of the visible light responsive photocatalyst are sufficiently exhibited. In particular, the thickness of the titanium peroxide layer is optimally 0.2 μm to 200 μm from the viewpoint of adhesion.

Next, the manufacturing method of the decorative board of this invention is demonstrated.
First, a visible light reflection layer and an oxidation-resistant resin layer are formed on a substrate surface made of at least one selected from the group consisting of a core paper, a magnesia cement incombustible base material, a gypsum board, and a metal plate. The substrate, the manufacturing method thereof, the visible light reflection layer, and the oxidation-resistant resin layer have been described in the description of the decorative board of the present invention, and are omitted here.

As described in the decorative board of the present invention, the method for forming the visible light reflection layer and the oxidation resistant resin layer on the substrate surface is not particularly limited, and can be performed by a general method. As a specific method for forming the visible light reflection layer and the oxidation-resistant resin layer, for example, melamine resin or the like is applied to a pattern paper that is whitened or glossed on one or both sides of a substrate made of a core paper laminate and adjusted in color. A first laminating step of laminating a melamine resin impregnated paper impregnated with a melamine resin, a second laminating step of laminating an oxidation resistant resin sheet impregnated with an oxidation resistant resin on an overlay paper on the melamine resin impregnated paper, and a melamine resin Examples thereof include a method including a hot press forming step of hot press forming a substrate on which impregnated paper and an oxidation resistant resin sheet are laminated. When the above method is used, the melamine resin of the melamine resin impregnated paper penetrates into the core paper, where the curing reaction proceeds, and the adhesive strength of the melamine resin impregnated paper to the core paper is expressed, and the melamine resin impregnated paper and the heat resistance The resin sheet is pressure-bonded, and a visible light reflection layer and a heat-resistant resin layer are formed on the substrate.
At this time, the reflectance (and reflection spectrum of visible light) corresponding to the color pattern printed on the pattern paper is arranged by arranging the surface on which the color pattern of the pattern paper is printed on the outer side (the side opposite to the substrate). ) Having a visible light reflecting layer.

The melamine resin-impregnated paper only needs to have a color pattern such that the reflectance of light having a wavelength of 430 to 500 nm is 60%, and such a color pattern may be printed on the pattern paper. In addition to the resin, a melamine resin-impregnated paper may be configured by adding a metal layer or the like. As the melamine resin-impregnated paper composed of a metal layer, pattern paper and resin, for example, a metal foil-pattern paper composite in which a metal foil serving as a metal layer is lined with a pattern paper may be impregnated with melamine resin. .

Examples of a method for obtaining an oxidation-resistant resin sheet containing an oxidation-resistant resin include a method of impregnating a sol solution containing an oxidation-resistant resin or the like into an overlay paper or the like having a low ash content, and drying.

In the above manufacturing method, a method of simultaneously forming a visible light reflecting layer and an oxidation resistant resin layer by laminating both melamine resin impregnated paper and an oxidation resistant resin sheet on a substrate and thermocompression bonding is described. However, the visible light reflection layer and the oxidation-resistant resin layer may be formed separately, for example, by laminating the melamine resin-impregnated paper on one or both sides of the substrate made of a core paper laminate, A process in which a paper-laminated substrate is hot-press-molded, an oxidation-resistant resin sheet is laminated on the surface of the hot-pressed substrate (that is, the surface of the visible light reflecting layer), and the oxidation-resistant resin sheet is laminated. The decorative board of the present invention can also be produced by a step of further thermo-thermoforming.

As a heating condition at the time of hot pressing, the temperature of the decorative board can be 125 to 150 ° C., and as a pressing condition, 1.96 to 9.80 MPa (20 to 100 kg / cm ² ). Can do. When the temperature is less than 125 ° C. or when the pressure is less than 1.96 MPa, the adhesion of the melamine resin-impregnated paper to the substrate is insufficient, and peeling easily occurs. On the other hand, when the temperature exceeds 150 ° C. or when the pressure exceeds 9.80 MPa, cracks may occur.

When a silane coupling agent is included in the oxidation resistant resin layer, a method of impregnating the oxidation resistant resin layer with the silane coupling agent by including the silane coupling agent in the oxidation resistant resin solution Can be used.
Further, after forming a visible light reflecting layer impregnated with a resin such as melamine resin, a silane coupling agent layer may be formed by coating or the like, and an oxidation resistant resin layer may be formed thereon.
By including a silane coupling agent in the oxidation resistant resin layer, the adhesion between the visible light reflective layer impregnated with a resin such as a melamine resin and the oxidation resistant resin layer can be improved.

The visible light responsive photocatalyst can be fixed on the oxidation resistant resin layer by applying the visible light responsive photocatalyst to an uncured oxidation resistant resin film or an overlay paper impregnated with an oxidation resistant resin. Then, a method of laminating with a paper impregnated with a pattern paper adjusted so that the reflectance of light at 430 to 500 nm after curing is 60% or more, and heating and pressing, a visible light responsive photocatalyst and inorganic There is a method in which a mixed solution of sol is applied to an oxidation resistant resin layer and dried, and an inorganic sol is gelled to fix a visible light responsive photocatalyst.
As a method of immobilizing a visible light responsive photocatalyst on an oxidation resistant resin layer with a dried inorganic sol, a substrate having an oxidation resistant resin layer is impregnated in a solution containing the visible light responsive photocatalyst and the inorganic sol. And a method of drying, a method of applying a solution containing a visible light responsive photocatalyst and an inorganic sol on the oxidation-resistant resin layer, and drying.
Immobilization of the visible light responsive photocatalyst can be reinforced by supporting the visible light responsive photocatalyst on the oxidation-resistant resin layer through the dried inorganic sol. As the inorganic sol, silica sol, alumina sol, silica-alumina sol, titania sol and the like can be used, and it is desirable to use silica sol.

In the visible light responsive photocatalyst, primary particles may be used as they are, or aggregated secondary particles may be used. In order to agglomerate the visible light responsive photocatalyst, the solution containing the visible light responsive photocatalyst may contain an aggregating agent. This is because the colloidal visible light responsive photocatalyst can be agglomerated by the aggregating agent. As the flocculant, polydiallyldimethylammonium chloride (manufactured by Aldrich Chemical Company, Inc.), anionic polyacrylamide (manufactured by High Holder 351 Kurita Kogyo Co., Ltd.) and the like can be used.

Example 1
(Melamine resin impregnated paper manufacturing process for visible light reflection layer)
On one surface of titanium paper having a thickness of 0.2 mm (titanium oxide content: 15% by weight), 30 parts by weight of titanium oxide, 10 parts by weight of styrene-acrylonitrile copolymer, 1 part by weight of aminomethylpropanol, 69 parts by weight of water Gravure printing on the entire surface with white ink. The titanium paper is impregnated with the melamine resin in the melamine resin solution so that the temperature of the solution is 20 ° C. and the immersion time is 2 minutes.
The titanium paper impregnated with the melamine resin solution was dried with a dryer at a temperature of 100 ° C. for 30 seconds. After drying, it is cut into 910 mm × 1820 mm to obtain a melamine resin-impregnated paper for visible light reflection layer.

(Oxidation resistant resin sheet production process)
Acrylic silicone resin emulsion (PCU-103 manufactured by Titanium Industry Co., Ltd.) is applied to overlay paper (talc content 0.5% by weight) with a thickness of 0.2 mm so that the solid weight is 77 g / m ^2. To impregnate. The overlay paper impregnated with the acrylic silicone resin emulsion is dried with a dryer at a temperature of 100 ° C. for 30 seconds. After drying, it is cut into 910 mm × 1820 mm to obtain an oxidation resistant resin sheet.

(Combination process)
Four sheets of phenol resin impregnated core paper having a thickness of 0.3 mm are laminated, and the melamine resin impregnated paper for visible light reflecting layer is placed thereon so that the color surface printed on the titanium paper is opposite to the core paper. A release cushion material made of PET is interposed between the press surface of the press machine and the melamine resin impregnated paper for the visible light reflection layer, and the temperature is 143 ° C., the press pressure is 80 kg / cm ² , and the press time (increase) Thermocompression bonding is performed in 50 minutes (including the warm time) (first lamination step).
Further, an oxidation-resistant resin sheet is laminated thereon, and a PET release cushioning material is interposed between the oxidation-resistant resin sheet and the press, and the temperature is 143 ° C., the pressing pressure is 80 kg / cm ² , and the pressing time is Thermocompression bonding is performed in 50 minutes (including the temperature raising time) (second lamination step).
Thereby, a visible light reflection layer and an oxidation resistant resin layer are formed on one surface of the substrate.

(Photocatalyst loading process)
A slurry in which a photocatalyst of Cu—TiO _{2 having} an average particle diameter of 100 nm is dispersed in water (solid content concentration: 25% by weight) and silica sol (SiO ₂ concentration: 3% by weight) are in a weight ratio of 4.5: 5.5. A methanol mixed solution (photocatalyst concentration 0.05% by weight) containing (solid weight) is prepared. The methanol mixed solution is applied to the surface of the oxidation-resistant resin layer of the substrate obtained in the above step using a spray, and dried at 25 ° C. for 12 hours, whereby the photocatalyst is supported via a silica sol dry body. Completes the production of finished decorative panels.
The solid content weight of the photocatalyst carried on the decorative plate is 0.11 g / m ² .

(Example 2)
(Melamine resin impregnated paper manufacturing process for visible light reflection layer)
Except that the white ink prepared in Example 1 was changed to an aluminum paste (trade name FD-512, manufactured by Asahi Kasei), the same procedure as in Example 1 was followed. A decorative board according to Example 2 is manufactured by performing two lamination steps and a photocatalyst supporting step.

Example 3
Instead of gravure printing with white ink, titanium is immersed in a 1 × 10 ⁻⁵ mol / liter aqueous solution of diaminostilbene disulfonic acid as a fluorescent whitening agent and dried at 100 ° C. for 30 seconds with a dryer. A decorative board according to Example 3 is manufactured by performing the oxidation-resistant resin sheet manufacturing process, the first laminating process, the second laminating process, and the photocatalyst supporting process in the same procedure as in Example 1, except that the color of the paper is adjusted. To do.

Example 4
In the above (first laminating step), the makeup according to Example 4 is performed in the same procedure as in Example 1 except that an aluminum foil having a thickness of 200 μm is further laminated on the melamine resin-impregnated paper for the visible light reflecting layer and thermocompression bonded. Manufacture a board.

(Comparative Example 1)
Manufacture of a decorative board is completed in the same procedure as Example 1 except having changed the color printed on the titanium paper used by (primary melamine impregnation process) to the wood grain.

(Evaluation of reflectance of visible light reflection layer)
Using the spectrocolorimeter [SC-P manufactured by Suga Test Instruments Co., Ltd.] with respect to the surface of the decorative board according to Example 1 and Comparative Example 1 (the surface on the side where the pattern was printed on the titanium paper), The reflectance of the visible light reflection layer is measured under the conditions. The reflectance is measured after the first stacking step and before the second stacking step in both the example and the comparative example.
The measurement method is spectral colorimetry method a (Sa), the effective wavelength width is 5 nm, the wavelength interval used for calculating the tristimulus values is 5 nm (W5), and the color matching function type is X ₁₀ Y ₁₀ Z ₁₀ color system. (CIE1964 color system), the measurement illuminant is the standard illuminant D65, the geometric condition of irradiation and light reception is the geometric condition c (de: 8 °), and the measurement hole is φ30 mm × 5 locations (selected at random). The measured reflection spectrum (average spectrum) is shown in FIG.
In addition, the whiteness index and the color index specified in JIS Z 8715 (1999) under the same conditions are W ₁₀ = 71, T _{W, 10} = 0.3 in Example 1, and W ₁₀ = − in Comparative Example 1. 65, T _{W, 10} = −25.2.

(Antiviral evaluation)
In order to evaluate the antiviral properties of the decorative plates obtained in Example 1 and Comparative Example 1, the antiviral properties are measured according to the antiviral test method of the visible light responsive photocatalytic material. The measurement result is expressed as the concentration of virus inactivated against E. coli. Here, the concentration of virus inactivated against E. coli (virus inactivity) is used as an indicator of virus concentration. Virus inactivity is an antiviral test using bacteriophage, and the concentration of virus capable of infecting E. coli is measured by using phage virus Qβ concentration: 8.3 million / ml. It is the result of having calculated the density | concentration of the virus inactivated with respect to it. That is, the virus inactivity is a degree of concentration at which E. coli cannot be infected with respect to the phage virus Qβ concentration, and (phage virus Qβ concentration−virus concentration capable of infecting E. coli) / (phage virus Qβ concentration) × 100. It can be said that the higher the virus inactivation value, the better the antiviral properties.
The concentration of virus capable of infecting E. coli is measured as follows. A test solution having a known phage virus concentration (8.3 million pieces / milliliter) is dropped on a decorative plate and irradiated with light according to JIS R1756 to inactivate the virus, and then the decorative plate is washed with a predetermined amount of water. This is diluted 1000 times, transplanted and cultured in an E. coli medium, and the number of inactivated viruses is counted. The concentration of virus capable of infecting E. coli is calculated from the number of inactivated viruses, the amount of water used for washing, and the dilution rate. The results are shown in Table 1.
Table 1 describes the reflectance in visible light (430 to 500 nm), virus inactivity, and virus inactivity.
The virus inactivity is a numerical value (negative value) represented by the common logarithm log (1-X) where the amount of the original virus is 1 and the amount of virus inactivated after virus inactivation is X. The greater the absolute value, the higher the ability to inactivate the virus. For example, when 99.9% of the original virus is inactivated, the virus inactivity is expressed as log (1−0.999) = − 3.00. The ratio of the amount of virus inactivated after virus inactivation treatment to the total amount of virus before virus inactivation treatment in% (in this case, 99.9%) is referred to as virus inactivity.

From the results shown in Table 1, the decorative plates according to Examples 1 to 4 are white or metallic in color, and the deterioration of the design due to the turbidity of the oxidation-resistant resin is not recognized, so that good design properties can be maintained. It was found that the function of the visible light responsive photocatalyst can be sufficiently exhibited.

DESCRIPTION OF SYMBOLS 1 Decorative board 10 Substrate 11 Visible light reflective layer 12 Oxidation resistant resin layer 13 Visible light responsive photocatalyst

Claims (8)

A substrate,
A visible light reflective layer laminated on one or both sides of the substrate;
An oxidation-resistant resin layer made of an oxidation-resistant resin disposed on the visible light reflection layer;
A visible light responsive photocatalyst disposed on the oxidation resistant resin layer,
The anti-viral decorative board, wherein the visible light reflection layer has a reflectance of light of 430 to 500 nm in light of 60% or more. 2. The antiviral property according to claim 1, wherein the visible light reflection layer is a composite made of a resin and a patterned paper containing at least one selected from the group consisting of a white pigment, a white dye, and a fluorescent brightening agent . Decorative board. The antiviral decorative board according to claim 2, wherein the white pigment is at least one selected from the group consisting of lead white, titanium oxide, zinc white, calcium carbonate, talc, silica and alumina. The antiviral decorative board according to claim 2, wherein the fluorescent whitening agent is at least one selected from the group consisting of a diaminostilbene type whitening agent, umbelliferone and esculin. 2. The antiviral decorative board according to claim 1, wherein the visible light reflection layer is a composite made of a pattern paper containing glossy particles and a resin. 6. The antiviral decorative board according to claim 5, wherein the glossy particles are metal particles or mica particles. The antiviral decorative board according to claim 1, wherein the visible light reflection layer includes a metal layer. The antiviral decorative board according to any one of claims 1 to 7, wherein the oxidation resistant resin is made of a silicone resin or a fluororesin.

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