Decorative board

Abstract

To provide a decorative laminate that has sufficiently enhanced surface hardness and maintains incombustibility without any special operation, such as baking finish to stick a special decorative sheet.SOLUTION: A decorative laminate includes two or more decorative layers on at least one surface of a base plate. An outermost decorative layer of the plurality of decorative layers and / or a decorative layer immediately below the outermost decorative layer is formed by a coating composition containing 35-90 mass% of glass beads in terms of a solid content.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a decorative board used for interior decoration and the like.

Background Art

[0002] Conventionally, various decorative boards have been used for interior finishing of buildings. Examples of decorative boards include those obtained by coating various paints such as urethane resin-based paints, acrylic resin-based paints, and epoxy resin-based paints on the surface of a substrate, and those obtained by adhering a sheet or film to the substrate. When a hard object hits these decorative boards, scratches and dents are likely to occur, and in many cases, it is difficult to repair them. Therefore, in order to maintain the design property for a long time, a high surface hardness is required. On the other hand, these decorative boards are required to meet the criteria for non-combustion certification under the Building Standards Act in order to ensure safety in the event of a fire or the like.

[0003] As a method for improving the surface hardness of a decorative board, there is a method of providing a sealer layer on a substrate (Patent Document 1). However, it has been difficult to obtain sufficient surface hardness only by providing a sealer layer. In order to obtain a higher surface hardness, there is also a method of applying a top coat in which glass beads are added to a high-density base paper and a coating film (Patent Document 2). However, this method has a problem that both the high-density base paper and the top coat are essential, and depending on the type of the substrate for laminating the sheet and the adhesive used when laminating the substrate and the sheet, non-combustibility cannot be ensured in the decorative board after lamination. There is also a method of obtaining a high-hardness coating film surface only with a top coat (Patent Document 3). However, this method requires a baking process, and since the substrate temperature at that time reaches 200 to 300°C, it has been difficult to apply it to a ceramic decorative board containing organic fibers such as pulp.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] Accordingly, an object of the present invention is to provide a decorative board having a sufficiently high surface hardness and ensuring non-combustibility without performing special operations such as baking treatment for adhering a special decorative sheet.

Means for Solving the Problems

[0006] Therefore, as a result of various studies by the present inventor to increase the surface hardness while ensuring non-combustibility, it has been found that by forming the outermost decorative layer and / or the decorative layer immediately thereunder among a plurality of decorative layers with a paint composition containing a specific amount of glass beads, a decorative board with significantly improved surface hardness and ensured non-combustibility can be obtained, and the present invention has been completed.

[0007] That is, the present invention provides the following inventions [1] to [5]. [1] A decorative board having two or more decorative layers on at least one surface of a substrate, wherein the outermost decorative layer and / or the decorative layer immediately thereunder among the plurality of decorative layers is formed of a paint composition containing 35% by mass or more and 90% by mass or less of glass beads per solid content. A decorative board characterized by that. [2] The decorative board according to [1], wherein the average particle diameter of the glass beads is 5 μm or more and 60 μm or less. [3] The decorative board according to [1] or [2], wherein the shape of the glass beads is spherical or irregular. [4] The decorative board according to any one of [1] to [3], wherein the decorative board is an interior decorative board. [5] The decorative board according to any one of [1] to [4], wherein the decorative board is a ceramic decorative board.

Effects of the Invention

[0008] The decorative board of the present invention has a sufficiently high surface hardness that is less likely to cause scratches and dents, and has non-combustible performance, so it is useful as an interior decorative board.

Embodiments for Carrying Out the Invention

[0009] The decorative board of the present invention is a decorative board having two or more decorative layers on at least one surface of a substrate, wherein the outermost decorative layer of the plurality of decorative layers and / or the decorative layer immediately below it is formed of a paint composition containing 35% by mass or more and 90% by mass or less of glass beads per solid content.

[0010] As the substrate of the decorative board of the present invention, a substrate for an interior decorative board, particularly a substrate for a ceramic decorative board, is preferable in terms of having non-combustible performance. Examples of the substrate for a ceramic decorative board include fiber-reinforced cement boards (including calcium silicate boards) for forming wall surfaces of houses, etc., wood-based cement boards, wood wool cement laminated boards, volcanic glass multi-layer boards, extruded cement boards, slag gypsum boards, lightweight foamed concrete boards, glass boards, ceramic boards, etc. Among these substrates, a fiber-reinforced cement board is more preferable.

[0011] These substrates are preferably substrates that use hydraulic cement such as Portland cement as the main raw material for forming the matrix, use fibers other than asbestos as the fiber raw material, and use admixtures such as wollastonite and calcium carbonate powder as raw materials as needed. Specifically, substrates such as fiber-reinforced cement boards defined in JIS A 5430 are preferable. In particular, 0.8 calcium silicate boards and 1.0 calcium silicate boards, which are a type of fiber-reinforced cement board formed using a calcareous raw material and a siliceous raw material as raw materials for forming the matrix and subjected to autoclave curing in the curing process, are substrates with excellent flexibility, high strength, and a small rate of change in length due to water absorption, and are thus suitable as the substrate for the ceramic decorative board of the present invention.

[0012] Examples of the fiber raw 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; and inorganic fibers such as glass fibers, carbon fibers (carbon fibers), rock wool fibers, and whiskers. In the present invention, from the viewpoint of improving the reinforcement and toughness of the decorative board even when the autoclave curing is employed, it is preferable to use pulp. Here, the pulp refers to a state in which cellulose is extracted by mechanically or chemically treating plant raw materials such as wood, and is so-called cellulose pulp. The content ratio of fibers in the fiber-reinforced cement board, particularly organic fibers such as pulp, varies depending on the matrix, but from the viewpoint of ensuring strength and incombustibility, it is preferably 5 to 9% by mass, and more preferably 6 to 8% by mass. If the content ratio of organic fibers such as pulp is low, the mechanical strength of the decorative board decreases, and cracks are likely to occur due to heat load, drying, carbonation, or impact. Conversely, if the content ratio of organic fibers such as pulp is high, it becomes difficult to maintain incombustibility.

[0013] The hydraulic cement may be any one generally used in the art, and examples thereof include Portland cement. Examples of the various additives used as needed include those generally used in the art and are not particularly limited. Examples thereof include powders such as wollastonite, mica, and calcium carbonate, and waste powder of fiber-reinforced cement boards and gypsum boards. When autoclave curing is performed, from the viewpoint of further increasing the strength by hydrothermal reaction curing with lime in the cement, a siliceous raw material, for example, crystalline silica such as powdered silica, and amorphous silica such as fly ash are added, and if necessary, a calcareous raw material, for example, quicklime, slaked lime, etc. are also added and adjusted so that the molar ratio of CaO / SiO2 of the matrix component is 0.7 to 1.2 before use.

[0014] 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.

[0015] Also, in the present invention, the bulk density of the substrate is preferably 0.6 to 1.8 g / cm 3 from the viewpoints of light weight, mechanical strength, and workability, and more preferably 0.6 to 1.2 g / cm 3 from the viewpoints of light weight, mechanical strength, and workability.

[0016] Also, in the present invention, the total heat release amount of the substrate is preferably 5 MJ / m 2 or less, more preferably 4.7 MJ / m 2 or less, from the viewpoint of non-combustibility.

[0017] In the present invention, the thickness of the substrate or the decorative board is a value measured in accordance with JIS A 5430:2013, paragraph 9.2.2 b). The bulk density is a value measured in accordance with JIS A 5430:2013, paragraph 9.5. The total heat release amount of the substrate is a value measured in accordance with JIS A 5430:2013, Appendix JA.

[0018] The decorative board of the present invention has two or more decorative layers on at least one surface of the substrate. In the case of an interior decorative board, particularly a ceramic decorative board, as the decorative layer, usually, a sealer layer, an undercoat layer, a coloring layer, a clear layer, etc. are applied from the surface of the substrate. Here, there may be a case where a clear layer is provided on the coloring layer, but there may also be a case where an enamel paint containing a pigment is adopted as the coloring layer and no clear layer is provided on its surface. In the present invention, the outermost decorative layer of the plurality of decorative layers and / or the decorative layer immediately thereunder are formed of a paint composition containing 35% by mass or more and 90% by mass or less of glass beads per solid content. Therefore, the outermost decorative layer of the present invention usually corresponds to the above-mentioned colored layer or clear layer. Further, the decorative layer immediately thereunder usually corresponds to a colored layer or an undercoat layer. Specifically, when forming the undercoat layer and / or the colored layer with a paint composition containing the glass beads, there may be a case of forming the colored layer and / or the clear layer with a paint composition containing the glass beads. However, when a printing layer is provided between the colored layer and the clear layer described later, it is assumed that the printing layer does not apply to the decorative layer immediately thereunder. Furthermore, it is also possible to overcoat a colored layer on the colored layer. In this case, a paint composition containing the glass beads may be used for either the colored layer on the substrate side or the colored layer on the surface side, or both the colored layer on the substrate side and the colored layer on the surface side. Further, it is also possible to provide a clear layer formed of a paint composition regardless of the presence or absence of the glass beads on the colored layer formed of the paint composition containing the glass beads. The content of the glass beads in the paint composition is the content of the glass beads per solid content of the paint composition used for forming each of the above layers.

[0019] Next, a sealer layer, an undercoat layer, a colored layer, and a clear layer, which are decorative layers, will be described. It is preferable to provide a sealer layer between the substrate of the decorative board and the undercoat layer. By providing the sealer layer, the surface layer of the substrate is strengthened, elution of alkali to the surface can be prevented, and the adhesion to the undercoat layer as the upper layer thereof is also improved. The sealer layer can be formed using a known sealer. For example, it is performed by applying a curable resin such as a moisture-curing urethane resin or an epoxy resin to the surface of the substrate and curing it. The sealer has good impregnation properties into the substrate, a high non-volatile content, and reacts with moisture in the substrate or atmospheric moisture to form a three-dimensional crosslink, and is a prepolymer having a free isocyanate group which is a reaction product of a polyisocyanate or a polyisocyanate and a polyol and a solvent such as butyl acetate as a main component, and a moisture-curing urethane-based one is suitable. Further, when yellowing as a decorative board becomes 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 viewpoint of recent VOC countermeasures, it is possible to use a solvent-free sealer or an aqueous sealer that does not contain a solvent, an inorganic sealer such as a silicate-based sealer such as lithium silicate or sodium silicate, or a silane compound-based sealer mainly composed of tetraethoxysilane or tetramethoxysilane. The formation of the sealer layer can be performed, for example, by heating the surface temperature of the fiber-reinforced cement board to 50 to 60°C, applying the sealer by a method such as a known roll coater or spray, and then curing it. The viscosity of the impregnating sealer can be appropriately determined in consideration of the type of impregnating sealer used and the coating method, and the curing can be performed, for example, by heating and drying. The organic solid content in the components of the impregnating sealer is preferably set to be 3 to 50 g per unit area (m 2 ) of the substrate.

[0020] The decorative board usually has a primer layer on the surface of the sealer layer. By forming the primer layer, uneven portions of various sizes and void portions existing on the surface of the substrate are filled with the paint, and the uneven feeling and the variation in gloss and color due to the suction spots of the paint are suppressed. In addition, the possibility of defects such as pinholes occurring in the decorative board can also be reduced.

[0021] The film thickness of the undercoat layer is preferably 5 to 100 μm in terms of the surface smoothness of the decorative board, the adhesion, formability, waterproofness, prevention of precipitation of base material components, prevention of coating film pinholes, coating film curability, surface foreign matter embedding property, and ease of film thickness management of the coating films above and below it. A more preferable film thickness is 20 to 90 μm, and even more preferably 25 to 70 μm. In this specification, the film thickness of the coating film layer formed of the paint composition containing glass beads is the thickness of the flat surface region that is not affected by the convex portions formed by the glass bead particles.

[0022] The paint composition for forming the undercoat layer is preferably an unsaturated polyester-based paint and / or an acrylate-based paint in terms of surface smoothness, chemical resistance, coating film adhesion, polishing processability, coating film hardness, ease of painting, and crack prevention. Specifically, allyl-based unsaturated polyesters such as epoxy acrylate, urethane acrylate, and diallyl phthalate, maleic acid-based unsaturated polyesters obtained by polycondensation of unsaturated dibasic acids such as maleic anhydride and fumaric acid with glycols, polyester monoacrylates having carboxyl groups or hydroxyl groups as functional groups, polyester diacrylates obtained from acrylic acid, dibasic acid, and dihydric alcohol, polyester polyacrylates such as polyester polyacrylates obtained from polyhydric alcohols with three or more valences, dibasic acids, and acrylic acid, oligomers such as epoxy acrylate oligomers and epoxy oligomers, acrylic polyethers, and polyether acrylates. Further, the paint composition for forming the undercoat layer is preferably an ultraviolet curable paint because of its ease of application, fast curing rate of the coating film, excellent grindability and durability of the coating film, and excellent adhesion to the substrate and the topcoat paint.

[0023] Examples of the coating method of the undercoat paint composition include methods using a roll coater or a flow coater. Among them, considering the effect of filling the large and small uneven portions and void portions present on the substrate surface with the paint, a roll coater is suitable. Also, from the viewpoint of uniformly applying the paint, a flow coater is suitable.

[0024] In the present invention, the amount of organic solid content contained in the undercoat layer is preferably 3 to 70 g, more preferably 10 to 65 g, and even more preferably 13 to 60 g per unit area (m 2 ) of the substrate. In this specification, the amount of organic solid content contained in the coating film layer can be obtained by coating amount (g / m 2 ) × solid content (%) of the coating composition × amount of organic component in the solid content of the coating composition.

[0025] For the undercoat painting to form the undercoat layer, it is possible to form the undercoat layer with a predetermined film thickness in one pass, or it is also possible to perform it two or more times to form the undercoat layer with a predetermined film thickness. For example, when forming the undercoat layer with a predetermined film thickness by performing the undercoat painting twice, first, the first undercoat painting is performed with an undercoat paint having a slightly high viscosity (200 to 600 dPa·s), and ultraviolet rays are irradiated while adjusting the irradiation amount of ultraviolet rays so that it is not completely cured. Next, after performing the second undercoat painting with an undercoat paint having a slightly low viscosity (20 to 60 dPa·s), ultraviolet rays are irradiated again to completely cure the entire undercoat paint. By doing so, the effect of filling the large and small uneven portions and void portions present on the substrate surface with the paint can be obtained in the first undercoat painting, and in the second undercoat painting, a smooth coating film surface of the undercoat layer can be obtained due to the self-leveling effect. Therefore, a good undercoat layer can be efficiently formed. Further, after completely curing the undercoat paint, polishing with a belt sander or the like can be performed to obtain an undercoat layer having a smoother surface.

[0026] On the surface of the undercoat layer, there is a colored layer. The film thickness of the colored layer is preferably 5 to 70 μm, more preferably 10 to 65 μm, and even more preferably 15 to 60 μm.

[0027] Examples of the inorganic coloring pigment contained in the coating composition for forming the colored layer include titanium oxide, zinc white, red iron oxide, yellow earth, chromium oxide green, ultramarine blue, carbon black, iron black, etc. It is more preferable to use one or a combination of two or more selected from these. Further, an organic pigment can be used in combination as needed. As the paint composition for forming the colored layer, an organic solvent-based paint or an aqueous paint can be used, and it is preferable to use a paint containing a resin such as an acrylic resin, a urethane resin, or an acrylic urethane resin having the above-described coloring pigment. Among them, an acrylic urethane resin paint is preferable, and it is more preferable to use a two-component curable acrylic urethane resin paint. Further, an epoxy resin paint, a polyurethane resin paint, a vinyl chloride resin paint, a vinylidene chloride resin paint, an acrylic silicone resin paint, a fluororesin paint, or the like may be used.

[0028] The method for forming the colored layer is not particularly limited, and it can be selected from known methods used in ordinary painting, such as a spray method, a roll coater method, a flow coater method, etc. Among them, coating by a roll coater or a flow coater is suitable, and when applying multiple coats in two or more steps, these methods may be appropriately combined and used.

[0029] In the present invention, the organic solid content in the components of the colored layer is preferably set to be 5 to 40 g per unit area (m 2 ) of the substrate, more preferably 10 to 35 g, and even more preferably 10 to 30 g.

[0030] The decorative panel may be provided with a clear layer on the surface of the colored layer. The film thickness of the clear layer is preferably 1 to 70 μm, more preferably 1 to 65 μm, and even more preferably 3 to 60 μm.

[0031] As the paint composition for forming the clear layer, an organic solvent-based paint or an aqueous paint can be used. For example, a two-component curable resin such as an acrylic silicone-based, urethane-based, acrylic-based, or acrylic urethane-based resin, a thermosetting resin, etc., a colorless transparent resin, and as other additives, for example, a wetting dispersant, an anti-settling agent, an antifoaming agent, a leveling agent, etc., and as a solvent, for example, butyl acetate, ethyl acetate, etc. are included. Among them, it is preferable to use a clear paint using an acrylic silicone-based or acrylic urethane-based resin excellent in weather resistance and stain resistance.

[0032] As a coating method for forming the clear layer, existing methods such as a flow coater, a roll coater, and a spray coater can be applied. The coating amount in the dry coating film of the clear layer is preferably 1 to 160 g, more preferably 2 to 140 g, per unit area (m 2 ) of the substrate. Further, from the viewpoint of ensuring nonflammability, the organic solid content in the clear layer is preferably 1 to 45 g, more preferably 2 to 35 g, further preferably 3 to 30 g, per unit area (m 2 ) of the substrate.

[0033] In the present invention, it is characterized in that the outermost decorative layer of the plurality of decorative layers and / or the decorative layer immediately therebelow are formed of a coating composition containing 35% by mass or more and 90% by mass or less of glass beads per solid content. Specifically, as described above, when forming the undercoat layer and / or the colored layer with a coating composition containing glass beads, there may be cases where the colored layer and / or the clear layer are formed with a coating composition containing glass beads. Among these, in order to maintain better hardness of the decorative board coating film, it is more preferable to form the colored layer and / or the clear layer with a coating composition containing glass beads, and it is even more preferable to form both the colored layer and the clear layer with a coating composition containing glass beads. In addition, by forming the colored layer or the clear layer with a coating composition containing glass beads on the colored layer formed with an existing coating composition not containing glass beads, the surface hardness can be improved compared to the colored layer formed with an existing coating composition not containing glass beads.

[0034] The glass beads to be contained in the coating composition used for forming these decorative layers may be beads of silicate glass, and the shape may be spherical or irregular. These glass beads may be of any type, not only for fillers, but also for road marking paints, blasting, grinding and dispersing, etc., and two or more types may be used in combination. Examples of commercially available glass beads include CF0002, CF0003, CF00017, CF0018, CF0027, CF00033, CF0093 (manufactured by Takara Standard Co., Ltd.), GB301S, GB731, GB210, EGB063Z, EGB731, EGB210, EMB-20, EMB-10 (manufactured by Potters Ballotini Co., Ltd.), UBS-0020L, UBS-0030L, UBS-02L, UBS-0010E, UBS-0020E, UBS-0030E, UB-02E (manufactured by Unitika Ltd.), etc. Glass beads whose surfaces have been surface-treated with a silane coupling agent such as aminosilane, glycidoxysilane, or acryl silane may also be used. In addition, from the viewpoint of the effect of improving the hardness of the decorative board coating film, the average particle diameter of the glass beads is preferably 5 μm or more and 60 μm or less, more preferably 5 μm or more and 50 μm or less, still more preferably 5 μm or more and 45 μm or less, and even more preferably 10 μm or more and 40 μm or less. Here, the average particle diameter of the glass beads is, for example, the average particle diameter measured by adopting a measurement method using image analysis based on an image of an electron microscope, a sieving method, a Coulter counter method, an electrical sensing zone method, a sedimentation method, or the like. In this specification, the average particle diameter (primary particle diameter) of the glass beads was specified by observation with a scanning electron microscope (SEM). Specifically, 50 randomly selected glass beads were observed with a scanning electron microscope, and the maximum diameter was taken as the particle diameter of the glass beads, and the average value of these was taken as the average particle diameter. The above maximum diameter was determined by drawing a straight line connecting any two points on the outer periphery of the glass beads in the SEM image, identifying the location where the length of the straight line was the maximum, and measuring the length of the straight line at that location as the maximum diameter.

[0035] The content per solid content of glass beads in the paint composition forming the outermost decorative layer or the decorative layer immediately below it is 35% by mass or more and 90% by mass or less from the viewpoint of improving the coating film hardness of the decorative board. If it is less than 35% by mass, a sufficient effect of improving the coating film hardness cannot be obtained, and if it exceeds 90% by mass, it becomes difficult to form the decorative layer. The preferable content per solid content of glass beads in the paint composition forming each decorative layer is 37% by mass or more and 85% by mass or less, more preferably 40% by mass or more and 85% by mass or less, still more preferably 45% by mass or more and 85% by mass or less, and even more preferably 50% by mass or more and 80% by mass or less. More specifically, when the paint composition forming the colored layer contains glass beads, the preferable amount is such that the content per solid content of glass beads is 35% by mass or more and 70% by mass or less, more preferably 45% by mass or more and 60% by mass or less, and even more preferably 50% by mass or more and 55% by mass or less. When the paint composition forming the clear layer contains glass beads, the preferable content per solid content of glass beads is 50% by mass or more and 90% by mass or less, more preferably 60% by mass or more and 85% by mass or less, and even more preferably 65% by mass or more and 80% by mass or less. Also, from the viewpoint of improving the coating film hardness of the decorative board, the total content per solid content of glass beads in the paint composition forming both the outermost decorative layer and the decorative layer immediately below it is preferably 30% by mass or more and 85% by mass or less, more preferably 30% by mass or more and 80% by mass or less, still more preferably 30% by mass or more and 75% by mass or less, and even more preferably 30% by mass or more and 70% by mass or less.

[0036] In addition, in the decorative board of the present invention, a printing layer can also be provided between the colored layer and the clear layer. By providing the printing layer, patterns such as wood grain or stone grain can be imparted to the decorative board. As the method of printing, existing methods such as gravure printing, gravure offset printing, inkjet printing, screen printing, rotary screen printing, relief printing, pad printing, etc. can be applied.

[0037] The decorative board of the present invention preferably has a total calorific value of 8 MJ / m 2 or less in the cone calorimeter heat release test. By satisfying this requirement, it meets the heat release grade 1 (heating time: 20 minutes) specified in JIS A 5430:2013, Annex JA, and exhibits high non-combustibility. A more preferable total calorific value is 7.2 MJ / m 2 or less.

Examples

[0038] Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples at all.

[0039] [Materials Used] (1) Glass beads (silicate glass), average particle diameters of 10 μm, 20 μm, and 40 μm (2) Glass beads (silicate glass, amino silane surface-treated), average particle diameter of 10 μm (3) Substrate 0.8 calcium silicate board

[0040] (4) Paint a. Urethane-based sealer (impregnating sealer) b. Acrylic epoxy-based UV curable paint (UV primer paint) c. Enamel paint (forming a colored layer) The enamel paint is a two-component curable acrylic urethane-based paint. d. Clear paint (forming a clear layer) The clear paint is a two-component curable acrylic urethane-based paint.

[0041] [Method for Forming Decorative Layer] Example 1 After polishing and smoothing the surface of the substrate using a belt sander, an impregnating sealer was applied at about 30 g / m 2 using a roll coater. On the impregnating sealer layer, about 120 g / m 2 of the primer paint was applied in two portions, cured by ultraviolet irradiation, and then polished using a belt sander to form a smooth primer layer. On top of the undercoat layer, apply enamel paint containing glass beads at a rate of approximately 100 g / m using a flow coater. 2 After application, the coating was dried and cured in a dryer at 90° C. for 20 minutes to form a colored layer, thereby obtaining a decorative board.

[0042] Example 2 After forming a primer layer in the same manner as in Example 1, an enamel paint not containing glass beads was applied on the primer layer at a rate of about 100 g / m using a flow coater. 2 After coating, the coating was dried and cured in a dryer at 90° C. for 20 minutes to form a colored layer, and a colored layer containing glass beads was further formed in the same process as for the colored layer, to obtain a decorative board.

[0043] Example 4 After forming a primer layer by the same process as in Example 1, enamel paint containing glass beads was applied on the primer layer at a rate of about 100 g / m using a flow coater. 2 The paint is then dried and hardened in a dryer at 90°C for 20 minutes to form a colored layer. After that, a flow coater is used to apply approximately 75 g / m of clear paint that does not contain glass beads. 2 The paint was applied, dried and hardened in a dryer at 90°C for 20 minutes to form a clear layer, and a decorative panel was obtained.

[0044] Example 11 After forming a primer layer by the same process as in Example 1, enamel paint containing glass beads was applied on the primer layer at a rate of about 100 g / m using a flow coater. 2 The paint is then dried and hardened in a dryer at 90°C for 20 minutes to form a colored layer. After that, a clear paint that does not contain glass beads is applied at a rate of approximately 10 g / m using a roll coater. 2 The paint was applied, dried and hardened in a dryer at 90°C for 20 minutes to form a clear layer, and a decorative panel was obtained.

[0045] Examples 3, 5 to 10, 12 to 17 and Comparative Example 1 Decorative panels were obtained by the same process as in Examples 1, 2 and 4 described above, adjusting the type and content of glass beads, and the type and amount of paint applied.

[0046] [Test Method] The hardness of the coating film surface was measured according to the "Pencil Scratch Test of JIS K 5400". The hardness was considered qualified if it was 7H or higher. According to the heat generation test (cone calorimeter heat generation test) specified in "JIS A 5430:2013, Annex JA", the total heat generation at 20 minutes of heating time was measured. For the appearance, the state of unevenness, streaks, etc. of the outermost decorative layer was observed with the naked eye at a distance of 1 m. When it was good, it was evaluated as ○, and when there was no problem in use but it was slightly concerning, it was regarded as △.

[0047] [Results] The measurement results are shown in Tables 1 and 2. The glass bead content in the table indicates the glass bead content (mass%) per solid content in the paint composition for forming each coating film.

[0048] [Table 1]

[0049] [Table 2]

[0050] From Table 1, when a paint composition without adding glass beads as in Comparative Example 1 was used, the hardness of the coating film of the decorative board was 3H, whereas when the outermost decorative layer (clear layer) and / or the decorative layer (colored layer) immediately below it was formed with a paint composition containing 35 - 90 mass% of glass beads (average particle diameter 20 μm), the hardness of the coating film of the decorative board became 7H or higher, indicating a remarkable improvement. Also, from Table 2, the same effect can be obtained if the average particle diameter of the contained glass beads is 10 - 40 μm. When the average particle diameter of the glass beads is 40 μm, the hardness of the coating film of the decorative board becomes 9H, but due to the large particle diameter, it is slightly lacking in the beauty of the appearance. Furthermore, when both the colored layer and the clear layer are formed with a paint composition containing glass beads, it can be seen that the hardness of the coating film of the decorative board is improved, and in more remarkable improvement examples, a coating film hardness of 9H is obtained. Regarding the exothermic test results, even in Example 8 with the largest amount of organic solid content, it is about 6.6 MJ / m 2 and similarly, the primary exothermic property is sufficiently satisfied for examples with less organic solid content than that.

Claims

1. A decorative panel having two or more decorative layers on at least one surface of a substrate, wherein the outermost decorative layer of the plurality of decorative layers and / or the decorative layer immediately below it is formed of a paint composition containing 35 mass % or more and 90 mass% or less of glass beads per solid content, characterized in that it is a decorative panel, wherein the average particle diameter of the glass beads is 10 μm or more and 40 μm or less, and the film thickness of the plurality of decorative layers is 15 to 60 μm. A decorative panel.

2. The decorative panel according to claim 1, wherein the shape of the glass beads is spherical or irregular.

3. The decorative panel according to claim 1 or 2, wherein the decorative panel is an interior decorative panel.

4. The decorative panel according to any one of claims 1 to 3, wherein the decorative panel is a ceramic decorative panel.

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