JP5985252B2 - Ceramic-based decorative board and manufacturing method thereof - Google Patents

Description

  The present invention relates to a ceramic-based decorative board having nonflammability and useful for interior and exterior use and a method for producing the same.

  In ceramic-type decorative boards such as calcium silicate, a multi-layered coating film made of an organic paint is formed on a ceramic-type board in order to impart weather resistance and appearance. A clear layer is provided on the uppermost part of the coating film in order to protect a decorative layer such as a colored layer and ensure a predetermined performance as a coating film. These organic coatings are basically flammable. On the other hand, the ceramics decorative board is made of calcium silicate and the like, and has non-flammable properties despite containing fibers such as pulp. Therefore, it is important to ensure nonflammable performance in ceramic-type decorative boards even if they have an organic coating film having good weather resistance and appearance.

  As means for ensuring the nonflammability of the decorative board provided with a clear layer, a method using inorganic sodium silicate and potassium silicate as a base treatment agent (Patent Document 1), fixed to the synthetic resin of the decorative layer and the top clear layer There have been reported a method (Patent Documents 2 and 3) in which an amount of a refractory is added, and a method (Patent Document 4) in which the amount of organic solid content in the organic coating film is constant.

JP 2011-246301 A JP 2011-92816 A JP 2011-94314 A JP 2011-163069 A

However, the method of using an inorganic material as a base treatment agent has a problem in the adhesion between the base material and the undercoat layer, and the method of blending a fireproofing agent in the synthetic resin has a problem in appearance characteristics and adhesion with other layers. In the method of limiting the organic solid content, the appearance characteristics and the like may be deteriorated.
Accordingly, an object of the present invention is to provide a ceramics decorative board with good adhesion and appearance of a coating film while ensuring sufficient nonflammability.

  Therefore, as a result of various studies to solve the above problems, the inventor polished the surface after forming the undercoat layer, and formed the uppermost clear layer with a roll coater. In addition to the above adjustment, the solvent clear layer can be formed thinly and uniformly, and as a result, it has been found that a ceramic decorative board having both sufficient incombustible performance and good appearance can be obtained, and the present invention has been completed.

That is, the present invention is a ceramic decorative plate, having an organic coating layer having an undercoat layer, a colored layer and a clear layer in this order on the surface of at least one side of the ceramic substrate,
(A) The undercoat layer is surface-polished and has a thickness of 5 to 100 μm,
(B) The thickness of the colored layer is 5 to 40 μm,
(C) The clear layer is composed of a 1 to 15 μm solvent clear layer and a UV clear layer applied with a roll coater, and the total film thickness is 30 to 100 μm.
(D) A ceramic-based decorative board characterized by having a total calorific value of 8 MJ / m ² or less according to a corn calorimeter exothermic test.

Further, the present invention is a method for producing a ceramics decorative board in which an undercoat layer, a colored layer and a clear layer are formed in this order on the surface of at least one side of a ceramics substrate,
(A) After forming the undercoat layer, the surface is polished, and the film thickness is 5 to 100 μm.
(B) The thickness of the colored layer is 5 to 40 μm,
(C) The clear layer is composed of a 1-15 μm solvent clear layer and a UV clear layer applied with a roll coater, and the total film thickness is 30-100 μm,
(D) The present invention provides a method for producing a ceramic-based decorative board having a total calorific value of 8 MJ / m ² or less according to a corn calorimeter exothermic test.

According to the present invention, since it has excellent adhesion, surface smoothness and the like, it has a good appearance and surface characteristics, and the total calorific value by a corn calorimeter exothermic test is 7.2 MJ / m ² or less, which is legally required. A ceramic decorative veneer that clearly clears 8 MJ / m ² or less can be provided.

The ceramics decorative board of the present invention (hereinafter also simply referred to as a decorative board) is a ceramics decorative board, and has an undercoat layer, a colored layer and a clear layer in this order on the surface of at least one side of the ceramics substrate. Having a coating layer,
(A) The undercoat layer is surface-polished and has a thickness of 5 to 100 μm,
(B) The thickness of the colored layer is 5 to 40 μm,
(C) The clear layer is composed of a 1 to 15 μm solvent clear layer and a UV clear layer applied with a roll coater, and the total film thickness is 30 to 100 μm.
(D) A ceramic-based decorative board having a total calorific value of 8 MJ / m ² or less according to a corn calorimeter exothermic test.

As the ceramic board of the present invention (ceramic board, hereinafter also simply referred to as a board), a fiber reinforced cement board (including calcium silicate board) forming a wall surface of a house, etc., a wooden cement board, wood wool A cement laminated board, a volcanic glassy multilayer board, an extrusion-molded cement board, a slag gypsum board, a lightweight cellular concrete board, a glass board, and a ceramic board are mentioned.
Of these substrates, fiber reinforced cement boards are more preferred.

  These substrates use, for example, hydraulic cement such as Portland cement as the main raw material for forming the matrix, use fibers other than asbestos as the fiber raw material, and if necessary, wollastonite, calcium carbonate powder, etc. In particular, it is a substrate such as a fiber reinforced cement board defined in JIS A 5430. In particular, as a raw material for forming a matrix, a calcium silicate board or 1.0 silicate board which is a kind of fiber reinforced cement board obtained by performing autoclave curing in a curing process using a calcareous raw material and a silicate raw material. The calcium acid plate is a substrate excellent in flexibility and has a high strength and a small rate of change in length due to water absorption, and is therefore suitable as a substrate for the ceramics decorative board of the present invention.

Examples of the fiber raw material include chemical pulp, wood pulp, cellulose pulp, polypropylene fiber, rayon fiber, acrylic fiber, vinylon fiber, nylon fiber, polyester fiber, and other organic fibers, steel fibers (steel wire fibers), amorphous metal fibers, and the like. Inorganic fibers such as metal fibers, glass fibers, carbon fibers (carbon fibers), rock wool fibers, whiskers, etc. of the present invention can be mentioned. In the present invention, even if the autoclave curing is adopted, the decorative plate is reinforced. From the viewpoint of improving the properties and toughness, it is preferable to use pulp.
In the fiber reinforced cement board, the content ratio of fibers, particularly organic fibers such as pulp, varies depending on the matrix, but is preferably 5 to 9% by mass from the viewpoint of ensuring strength and incombustibility, and 6 to 8%. More preferably, it is mass%. When the content ratio of organic fibers such as pulp is small, the mechanical strength of the decorative board is lowered, and cracking due to heat load, drying, carbonation, and impact tends to occur. Conversely, if the content of organic fibers such as pulp is high, it becomes difficult to maintain nonflammability.

As hydraulic cement, what is generally used in this industry should just be mentioned, for example, Portland cement is mentioned. In the present invention, it is desirable not to use a pneumatic cement such as gypsum from the viewpoint of water resistance.
Various additives used as necessary include those commonly used in the industry, and are not particularly limited. For example, powders such as wollastonite, mica and calcium carbonate, fiber reinforced cement board Examples include waste powder. In addition, when performing autoclave curing, from the point of further increasing the strength by hydrothermal reaction hardening with lime in cement, siliceous raw materials, for example, crystalline silica such as powdered meteorite, amorphous silica such as fly ash, etc. Are preferably mixed and used as necessary.

  In the present invention, the thickness of the substrate is preferably 3 to 6.5 mm. When the thickness is too thin, the impact resistance is deteriorated, and the surface smoothness is impaired by the strain after the construction, which is particularly unsuitable as a decorative board. Conversely, when too thick, mass will increase, workability will fall, and it will also lead to a raise of cost. More preferably, the thickness of the substrate is 3.5 to 5.5 mm.

In the present invention, the apparent density of the substrate is preferably 0.6 to 1.8 g / cm ³ . When the density is too small, the surface of the base material becomes rough, and sealer sucking spots are generated, thereby deteriorating the appearance after painting. In addition, frost damage resistance is reduced, and mechanical properties such as rigidity and breaking load are reduced. If the density is too large, the mass increases and the workability decreases. The apparent density of the substrate is more preferably 0.7 to 1.2 g / cm ³ .

In the present invention, the total amount of heat generated by the substrate is preferably at most 5 MJ / m ^2, and even more preferably 4.7MJ / m ² or less. If it exceeds 5 MJ / m ² , it will be difficult to satisfy the non-flammability after making the decorative board, and it will be difficult to maintain the water resistance and weather resistance at desired levels.

In the present invention, the thickness of the substrate or decorative board is a value measured according to JIS A 5430: 2008, paragraph 10.2.2. The apparent density is a value measured according to JIS A 5430: 2008, 10.5.
The total heat generation amount of the substrate is a value measured according to JIS A 5430: 2008, 10.9 paragraph b).

  The decorative board of the present invention has an undercoat layer, a colored layer, and a clear layer in this order on the surface of at least one side of the substrate. These organic coating layers may be provided on only one surface (one surface) of the substrate or on both surfaces.

It is preferable to provide an impregnated sealer layer between the substrate and the undercoat layer, that is, on at least one surface of the substrate, if necessary. By providing the impregnated sealer layer, the surface layer of the substrate is strengthened, the elution of alkali to the surface can be prevented, and the adhesion with the undercoat layer serving as the upper layer is improved.
The impregnated sealer layer can be formed using a known sealer. For example, the impregnated sealer layer is formed by applying a curable resin such as a moisture curable urethane resin or an epoxy resin to the surface of the substrate and curing it. The impregnation sealer has good impregnation into the substrate, has a high non-volatile content, and reacts with moisture in the substrate or moisture in the atmosphere to form a three-dimensional cross-link. A moisture-curing urethane-based material mainly comprising a prepolymer having a free isocyanate group as a reaction product and a solvent such as butyl acetate is preferred. Moreover, 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). It should be noted that a solvent-free sealer that does not contain a solvent can be used from the viewpoint of VOC countermeasures in recent years.
The impregnation sealer layer can be formed, for example, by heating the surface temperature of the fiber reinforced cement board to 50 to 60 ° C., applying the impregnation sealer by a method such as a known roll coater or spray, and then curing. The viscosity of the impregnating sealer can be appropriately determined in consideration of the type of impregnating sealer to be used and the coating method, and the curing can be performed by, for example, drying by heating.

In this invention, it is preferable to set so that the amount of organic solids in the component of an impregnation sealer may be 3-100g per unit area (m < ² >) of a board | substrate. If the organic solid content is too small, the surface layer of the substrate may not be strengthened so much. In addition, the adhesion with the undercoat layer that is the upper layer may be lowered. If the amount of organic solids is too large, excess organic solids will remain on the surface layer of the substrate, and this organic solid layer can cause defects such as cohesive peeling in the sealer layer, foaming in the subsequent process, and side walls. There is sex. In addition, aside is a minute hole made by the gas in the foam breaking the coating in foaming. It is caused by a local thick film at the time of painting, and is mainly caused by a rapid temperature rise at the time of drying. . More preferably, the organic solid content in the impregnated sealer component is set to 20 to 70 g per unit area (m ² ) of the substrate.

  In the present invention, the amount of organic solids can be easily calculated from the composition of the coating stock solution, the amount of diluent used, and the actual coating amount.

  The decorative board of the present invention has an undercoat layer on the substrate surface or the impregnated sealer layer surface, the surface of the undercoat layer is polished, and it is important that the film thickness is 5 to 100 μm. By forming the undercoat layer, large and small uneven portions and void portions existing on the surface of the substrate are filled with the paint, and the uneven feeling and the gloss / color variation feeling due to the paint suction spots are suppressed. In addition, the possibility of defects such as pinholes on the decorative board is reduced. Further, after the undercoat layer is formed, the surface is polished. By performing the polishing treatment, the base becomes smooth, the design properties of each coating film formed thereon are not impaired, not only provide good appearance, but also a smooth thin solvent clear layer and UV clear layer Can be formed.

  The film thickness of the undercoat layer is 5 to 100 μm, and the surface smoothness of the decorative board and the adhesion to the upper and lower coating films, formability, waterproofness, prevention of deposition of base material components, coating film pinholes Are important in terms of prevention of coating, film curability, surface foreign matter burying property, and ease of film thickness control. If the thickness is less than 5 μm, the adhesion between the upper layer and the lower layer may decrease, and if it exceeds 100 μm, the total calorific value increases, which may lead to deterioration of incombustibility. A preferable coating film is 20-90 micrometers, More preferably, it is 25-70 micrometers.

  The paint for forming the undercoat layer is preferably an unsaturated polyester-based paint from the viewpoint of surface smoothness, chemical resistance, coating film adhesion, polishing processability, coating film hardness, coating ease, and crack resistance. Specifically, allyl unsaturated polyesters such as epoxy acrylate, urethane acrylate, diallyl phthalate, maleic unsaturated polyesters by polycondensation of unsaturated dibasic acids such as maleic anhydride and fumaric acid with glycols, etc. Is mentioned. Moreover, it is preferable that the coating material is a two-component curable coating material because the curing rate of the coating film can be controlled. After applying the paint, it is cured to form an undercoat layer and then polished as described above. Examples of the coating method include a method using a roll coater, a flow coater, and the like. Among these, a roll coater is suitable in consideration of the effect of filling large and small uneven portions and void portions on the substrate surface with a paint. Apart from this, a flow coater is suitable from the viewpoint of applying the paint uniformly.

In the present invention, the organic solid content in the component of the undercoat layer is preferably set to ^{2 to} 50 g per unit area (m ² ) of the substrate, and more preferably 10 to 40 g.

  Examples of the polishing means after forming the undercoat layer include buffing, platen polishing, polisher polishing, blast polishing, etching polishing, grinding wheel polishing, felt polishing, brush polishing, laser polishing, cutting with an end mill or a bite, etc. Platen polishing is preferable from the viewpoint of smoothing the surface of the layer and polishing properties. In the platen polishing, an endless belt-like polishing paper that is driven to rotate is pressed against the object to be polished with a soft pad, and the object to be polished is advanced and polished. The undercoat layer is preferably polished within a range of 100 μm or less, and the final undercoat layer thickness is preferably 5 to 100 μm.

  The decorative board of the present invention has a colored layer having a thickness of 5 to 40 μm as an upper layer of the undercoat layer. By forming the colored layer, the decorative board of the present invention has a good appearance, cosmetics (designability), smoothness, and a base concealing property (so that the color of the base material itself does not affect the appearance of the decorative board) Concealment). Moreover, the film thickness of a colored layer needs to be 5-40 micrometers from the point of an external appearance, provision of cosmetics, and ensuring nonflammability, 10-40 micrometers is more preferable, and 15-35 micrometers is more preferable. If the colored layer exceeds 40 μm, the coating layer will be biased in the colored layer formation process, resulting in unevenness in the colored layer, and bubble traces tend to remain inside or on the colored layer. Tends to be uneven and the appearance tends to deteriorate.

The paint used for forming the colored layer is preferably a paint containing a pigment in a high concentration, specifically, a pigment such as titanium amount or graphite; a resin such as acrylic resin, urethane resin or acrylic urethane resin; solvent; addition A paint containing a component such as an agent is preferred, and a two-component curable paint is more preferred.
The pigment is preferably contained in the paint in an amount of 30 to 50% by mass, thereby obtaining good colorability and ensuring nonflammability. The colored layer may be formed by a roll coater or a flow coater. The amount of organic solids in the colored layer is preferably 3 to 60 g, more preferably 20 to 50 g per unit area (m ² ) from the viewpoint of securing colorability and nonflammability.
In addition, after the colored layer is formed, it is preferable to polish the surface by buff polishing, platen polishing, polisher polishing, or the like from the viewpoints of clear layer formation and cosmetic properties.

  In the decorative board of this invention, you may provide a printing layer between a colored layer and a clear layer as needed. By providing the printed layer, it is possible to impart even better appearance and cosmetic properties to the decorative board.

The paint for forming the printing layer may be any paint that can form shapes such as patterns and letters. For example, a paint containing a resin such as a pigment, an acrylic resin, a urethane resin, or an acrylic urethane resin, a solvent, and an additive. Is mentioned. The application means is preferably gravure printing, gravure offset printing, inkjet, screen printing, rotary screen printing, letterpress printing, or pad printing. The film thickness of the printing layer is preferably from 0.1 to 5 μm, more preferably from 0.1 to 2 μm, and even more preferably from 0.3 to 2 μm from the viewpoint of ensuring the formability of the pattern and the like and nonflammability. The amount of organic solid content in the printed layer is preferably 0.03 to 10 g, more preferably 0.1 to 7 g per unit area (m ² ). Further, it is preferable not to polish after the formation of the printing layer.

  In the decorative board of the present invention, it is important to form a clear layer having a total film thickness of 30 to 100 μm composed of a solvent clear layer and a UV clear layer in a film thickness of 1 to 15 μm on the colored layer or the printed layer. Yes, the solvent clear layer is applied by a roll coater. The solvent clear layer has good adhesion with the colored layer or the printing layer, but the coating film performance is not always sufficient. On the other hand, the UV clear layer has the property that the coating film performance is good but the adhesion with the printing layer is insufficient. Therefore, it is preferable to form the solvent clear layer on the colored layer or the print layer and form the UV clear layer thereon. Moreover, in order to obtain the surface smoothness as a decorative board, it is necessary to ensure high surface smoothness at the stage of forming the solvent clear layer. Furthermore, since a decorative sheet with a glossy surface gives a product a feeling of richness and luxury by a UV clear layer having a certain thickness, the method of thinning the UV clear layer has a great influence on the appearance of the product. Therefore, it was possible to form a solvent clear layer that was thinner and superior in surface smoothness by roll coater coating.

  When the film thickness of the solvent clear layer is less than 1 μm, good surface smoothness cannot be obtained, uniform application is difficult, and the adhesion of the UV clear layer becomes insufficient. On the other hand, if the film thickness exceeds 15 μm, the film thickness of the entire clear layer increases, and it is not sufficient to ensure nonflammability. The film thickness of a more preferable solvent clear layer is 1-10 micrometers, More preferably, it is 1-8 micrometers, More preferably, it is 2-7 micrometers.

The total film thickness of the solvent clear layer and the UV clear layer is 30 to 100 μm, preferably 30 to 80 μm, and more preferably 30 to 60 μm. If it is less than 30 μm, sufficient strength cannot be obtained, and the coated surface is difficult to be smooth, so that the design property tends to be reduced. On the other hand, if it exceeds 100 μm, it is difficult to ensure sufficient nonflammability.

  In addition, the solvent clear layer has a thin film thickness, improved adhesion due to the paint rubbing effect on the coating layer surface formed in the previous process, ease of application amount management, filling effect in fine holes, unevenness It is applied by a roll coater from the standpoint of followability and ease of application of low viscosity paint.

  The clear layer is not particularly limited as a paint for forming the solvent clear layer as a protective layer, and examples thereof include two-component curable resins such as acrylic silicone, urethane, and acrylic, and thermosetting resins. A colorless transparent resin comprising the above or a translucent resin containing a matting agent in the resin, and other additives such as wetting and dispersing agents, anti-settling agents, antifoaming agents, and leveling agents, and solvents such as butyl acetate and acetic acid The thing containing ethyl etc. is mentioned. Among them, it is preferable to use an acrylic silicone type resin or an acrylic urethane type resin that is excellent in weather resistance and stain resistance. The term “transparent or translucent” as used in the present invention means that the total light transmittance is 40% or more, more preferably 50% or more. The total light transmittance can be measured by a conventionally known method using a haze meter or the like. A roll coater method is used as a coating method.

  The paint for forming the UV clear layer is not particularly limited, but acrylic urethane, polyester resin, alkyd resin, polyether resin, acrylic resin, epoxy resin, urethane resin, silicon resin, polybutadiene A colorless transparent resin comprising a UV curable resin such as a mixture of an ultraviolet polymerizable compound having an unsaturated double bond capable of radical polymerization such as a resin system and a photoinitiator, or a mixture of a cationic ring-opening polymerizable compound and a photoinitiator, or A translucent resin is preferred. Examples of the paint include those containing, for example, a wetting and dispersing agent, an anti-settling agent, an antifoaming agent, and a leveling agent as other additives, and those containing, for example, butyl acetate and ethyl acetate as solvents. The coating method is preferably a flow coater method, but other methods such as a roll coater method and a spray method may also be used.

In this invention, it is preferable to set so that the organic solid content in the component of a clear layer may be 20-100g per unit area (m < ² >) of a board | substrate, and also 20-80g.

The decorative board of the present invention is a manufacturing method in which an undercoat layer, a colored layer and a clear layer are formed in this order on the surface of at least one side of a ceramic substrate,
(A) After forming the undercoat layer, the surface is polished, and the film thickness is 5 to 100 μm.
(B) The thickness of the colored layer is 5 to 40 μm,
(C) The clear layer is composed of a 1-15 μm solvent clear layer and a UV clear layer applied with a roll coater, and the total film thickness is 30-100 μm,
(D) It can be manufactured by a manufacturing method in which the total calorific value by a corn calorimeter exothermic test is 8 MJ / m ² or less. The method for forming each coating layer is as described above.

The decorative board of the present invention needs to have a total calorific value of 8 MJ / m ² or less by a corn calorimeter exothermic test. Satisfying this requirement satisfies exothermic first grade (heating time 20 minutes) defined in JIS A 5430: 2008, and exhibits high nonflammability. A more preferable total calorific value is 7.2 MJ / m ² or less.
In addition, when piled up the manufactured decorative board for storage and transportation, it is preferable to cool the board temperature to 40 ° C. or lower in order to avoid so-called blocking.

  EXAMPLES Hereinafter, although an Example and a comparative example further demonstrate this invention, this invention is not restrict | limited to the following example.

(1) Fiber reinforced cement board (substrate)
Hilac M (manufactured by A & A Materials Co., Ltd.) was used as the substrate. Hilac M is a fiber reinforced cement board corresponding to “calcium silicate board type 2 1.0 calcium silicate board” in Table 1 of JIS A 5430. Hilac M used in Examples and Comparative Examples is a mixture of 7% by mass of pulp as an organic fiber raw material.

(2) Formation of each layer Each coating film was formed using the following paint.
Impregnated sealer layer: DIC Corporation UC Sealer W004K
Undercoat layer: DIC Corporation SKS-WP
Colored layer: China Paint Co., Ltd. EP Coat No. 300U white FTX
Printing layer: DIC Color Co., Ltd. GO ink Solvent clear layer: China Paint Co., Ltd. EP Coat No. 300-60 clear UV clear layer: China Paint Co., Ltd. 230 SX

Example 1
An impregnating sealer was applied to the front and back surfaces of the substrate using a roll coater at 75 g / m ² to form an impregnated sealer layer having an organic solid content of 30 g / m ^{2 over the} entire front and back surfaces of the substrate.
Next, after applying 120 g / m ² of the undercoat paint on the substrate surface side using a roll coater, the paint film is cured by ultraviolet irradiation, and the surface of the undercoat paint is polished smoothly by a platen polishing machine, An undercoat coating layer having an organic solid content of 25 g / m ² at 51 μm was formed.
Furthermore, 110 g / m ² of enamel paint from China Paint Co., Ltd. was applied as a colored layer from above the undercoat layer using a roll coater and flow coater, and after standing, the coating film was cured with a hot air dryer, The surface of the colored layer was polished using a polishing machine to form a colored layer having a coating thickness of 28 μm and an organic solid content of 30 g / m ² .
Next, as a printing layer, a printing layer having a thickness of 1 μm or less and an organic solid content of 5 g / m ² was formed on the surface of the colored layer using a gravure offset printer. Further, 13 g / m ^{2 of} solvent clear paint was applied to the printed surface using a roll coater, and after standing, the coating film was cured in a hot air drying oven, and then the surface of the solvent clear layer was buffed and polished by a polisher. And a solvent clear layer having a coating film thickness of 6 μm and an organic solid content of 8 g / m ² was formed.
Furthermore, a UV clear coating was applied to the surface of the solvent clear layer using a flow coater at 50 g / m ² and allowed to stand, and then the coating film was cured by an ultraviolet irradiation device, the coating thickness was 44 μm and the organic solid content was A decorative plate was prepared by forming a 44 g / m ² UV clear layer.

Example 2
Using the same paint and coating method as in Example 1, an undercoat layer having an undercoat layer thickness of 61 μm and an organic solid content of the undercoat layer of 30 g / m ² was formed. A decorative board having a thickness of 5 μm, an organic solid content of the solvent clear layer of 5 g / m ² , a coating thickness of the UV clear layer of 47 μm and an organic solid content of the UV clear layer of 47 g / m ² was prepared. The structure of the other coating layer is the same as in Example 1.

Example 3
An impregnated sealer layer was formed in the same manner as in Examples 1 and 2. For the undercoat layer, the polishing amount of the undercoat layer by a platen polishing machine was increased from that in Example 1, and the coating thickness of the undercoat layer was 31 μm and the organic solid content was 15 g. The undercoat layer was / m ² . In addition, a decorative layer having a colored layer of 27 μm and an organic solid content of 29 g / m ² , a solvent clear layer of 5 μm and an organic solid content of 7 g / m ² , a UV clear layer of 53 μm and an organic solid content of 53 g / m ² was prepared. . Others are the same as in the first embodiment.

Example 4
For the undercoat layer after the impregnation sealer layer was formed, the coating thickness was adjusted by polishing in the same manner as in Example 3, so that the coating thickness was 26 μm and the organic solid content was 13 g / m ² . A decorative board having a solvent clear layer of 5 μm and an organic solid content of 7 g / m ² and a UV clear layer of 47 μm and an organic solid content of 47 g / m ² was prepared. Others are the same as in the first embodiment.

Example 5 (example in which the undercoat layer is thin)
For the undercoat layer, the coating thickness was 15 μm and the organic solid content was 7 g / m ² in the same manner as in Examples 3-4. Others are the same as in the first embodiment.

Example 6 (example where the colored layer is thin)
A decorative plate was prepared in the same manner as in Example 1 with an enamel coating amount of 55 g / m ² for the colored layer. The coating thickness of the colored layer was 15 μm and the organic solid content was 16 g / m ² . Others are the same as in the first embodiment.

Example 7 (Example of a solvent clear layer of about 10 μm)
For the solvent clear layer, a solvent clear coating was applied with a roll coater at 25 g / m ² , and the surface was polished after the coating was cured to form a solvent clear layer having a coating thickness of 10 μm and an organic solid content of 13 g / m ² . . Others are the same as in the first embodiment.

Comparative Example 1 (Applied except for roll coater)
The construction from the impregnated sealer layer to the printed layer is the same as in Example 4, and the solvent clear layer is coated at 80 g / m ^{2 with} a flow coater, the surface is polished after curing, and the coating thickness is 21 μm and the organic solid A solvent clear layer having an amount of 28 g / m ² was formed. Further, for the UV clear layer, a decorative board having a coating thickness of 90 μm and an organic solid content of 90 g / m ² was prepared.

Comparative Example 2 (example in which the clear layer was formed only with solvent clear)
The configuration from the impregnated sealer layer to the printed layer was the same as in Comparative Example 1. The solvent clear layer was coated with 150 g / m ² using a flow coater, and a solvent clear layer having an organic solid content of 45 μm and an organic solid content of 60 g / m ² was formed on the surface of the printed layer to obtain a decorative board.

Comparative Example 3 (example where the undercoat layer is thick, no polishing)
An impregnated sealer layer was formed in the same manner as in Example 4, and then an undercoat was applied to the surface side of the substrate at 120 g / m ² using a roll coater. After curing the undercoat paint by ultraviolet irradiation, an undercoat paint film having a thickness of 110 μm and an organic solid content of 60 g / m ² was formed without polishing the undercoat paint film. A decorative board was prepared in the same manner as in Example 4 from the colored layer to the UV clear layer.

Comparative example 4 (example with thick colored layer)
After the impregnated sealer layer and the undercoat layer were formed in the same manner as in Example 4, an enamel coating was applied as a colored layer at 200 g / m ² using a roll coater and a flow coater. After the coating was cured, buffing was performed to form a colored layer having a coating thickness of 50 μm and an organic solid content of 54 g / m ² . The printing layer, solvent clear layer, and UV clear layer are all the same as in Example 4.

(3) Evaluation Specific gravity: Measured according to JIS A5430-10-5.
Total calorific value: Measured according to a cone calorimeter [exothermic test by exothermic test equipment for fireproof materials (Building Materials Testing Center) (conforms to ISO 5660 Part 1)].
Appearance: GOOD by visual observation, ◯, unsatisfactory by x, and intermediate between these, Δ.
Pencil hardness: Measured according to JIS K5600-5-4.

  The obtained evaluation results are shown in Table 1.

As is apparent from Table 1, an undercoat layer, a colored layer, and a clear layer are formed on the surface of the fiber reinforced cement board, each layer has a predetermined thickness, the undercoat layer is polished, and the clear layer is 1 to 15 μm with a roll coater. By using the solvent clear layer and the UV clear layer, a ceramic-type decorative board having excellent appearance and strength and excellent incombustibility with a total calorific value of 7.2 MJ / m ² or less can be obtained.
On the other hand, Comparative Example 1 having a thick solvent clear layer of 21 μm has a total calorific value as high as 8.2 MJ / m ^2, and Comparative Example 2 having only the solvent clear layer without providing the UV clear layer (the flow layer is a clear coater). In the case of coating), the appearance was not good and the surface strength was insufficient.

Claims (6)

A method for manufacturing a ceramic decorative panel, in which an undercoat layer, a colored layer, and a clear layer are formed in this order on the surface of at least one side of a ceramic substrate,
(A) After forming the undercoat layer, the surface is polished, and the film thickness is 5 to 100 μm.
(B) The thickness of the colored layer is 5 to 40 μm,
(C) The clear layer is composed of a 1-15 μm solvent clear layer coated with a roll coater and a UV clear layer , a solvent clear layer is formed on the colored layer, and a UV clear layer is formed thereon. The film thickness is 30 to 100 μm,
(D) A method for producing a ceramic decorative veneer having a total calorific value of 8 MJ / m ² or less by a corn calorimeter exothermic test. Method of manufacturing a ceramic-based decorative board according to claim 1, wherein polishing the colored layer forming after surface. (D) The method according to claim 1 or 2 , wherein the total calorific value by a corn calorimeter exothermic test is 7.2 MJ / m ² or less. The manufacturing method of the ceramics type decorative board according to any one of claims 1 to 3 , wherein an impregnated sealer layer is provided between the ceramics type substrate surface and the undercoat layer. The manufacturing method of the ceramics type decorative board in any one of Claims 1-4 which provide a printing layer between (b) a colored layer and (c) a clear layer. The method for producing a ceramics decorative board according to any one of claims 1 to 5, wherein the solvent clear layer is an acrylic silicone or acrylic urethane resin.