JP5409425B2 - Decorative plate and method for producing the same - Google Patents

Description

  The present invention relates to a decorative board and a method for producing the same, and more particularly to a decorative board having nonflammability and excellent surface smoothness, appearance, water resistance, weather resistance and handling properties, and a method for producing the same. The decorative board of the present invention is particularly useful as an exterior decorative board.

  Conventionally, when a fiber reinforced cement board is used as an exterior decorative board, the surface is painted to provide weather resistance and appearance. However, the coating film for maintaining such surface performance is a combustible material and does not have nonflammability. Therefore, the decorative plate of the prior art has been neglected in terms of incombustibility required for safety such as a fire, because importance is attached to weather resistance and appearance.

The following Patent Document 1 discloses an exterior material that is formed by providing a base material with a sealer coating, an enamel coating, and a clear coating in this order, and the clear coating used to form the clear coating is acrylic. In addition to being an emulsion paint, an exterior material having a resin solid content of 20 to 33% by mass and a paint viscosity of 5 to 80 mPa · s when the clear paint is applied is disclosed.
However, even in the technique disclosed in Patent Document 1, weather resistance and appearance are regarded as important, and no consideration is given to incombustibility.

JP 2008-246340 A

The object of the present invention is to provide a decorative board that solves the above-mentioned conventional problems, and that has both the weather resistance, the appearance, and the like that are conventionally required for a decorative board, and the non-flammability that is the opposite of the performance. There is.
More specifically, an object of the present invention is to provide a decorative board having nonflammability and excellent surface smoothness, appearance, water resistance, weather resistance and handling properties, and a method for producing the same.

As a result of intensive research, the present inventors have determined that the thickness, apparent density, and pulp content ratio of the fiber-reinforced cement board as a base material are within a specific range and a specific coating formed on the surface thereof. It was found that the above problems can be solved by setting the total amount of organic solids in the film within a certain range, and the present invention has been completed.
That is, the present invention is as follows.

1. At least one surface of the fiber reinforced cement board is subjected to an impregnation sealer treatment, and a surfacer coating film, an enamel coating film and a clear coating film are formed in this order on the impregnation sealer processing surface, and the following conditions (1) to (3 ), A decorative board characterized by satisfying all of
(1) The fiber reinforced cement board has a thickness of 3 to 6.5 mm, an apparent density of 1.4 to 1.8 g / cm ³ , and a content ratio of pulp as a reinforcing fiber of 5 to 8 % By mass. (2) The total amount of organic solids contained in the impregnated sealer component, the surfacer coating component, the enamel coating component and the clear coating component is 63 per unit area (m ² ) of the fiber-reinforced cement board. ~ 130 g.
(3) The total calorific value of the decorative board is 8 MJ / m ² or less.

2. The amount of organic solid in the component of the impregnated sealer is 3 to 10 g per unit area (m ² ) of the fiber-reinforced cement board,
The organic solid content of the surfacer coating film is 10 to 30 g per unit area (m ² ) of the fiber reinforced cement board,
An organic solid content of the enamel coating film is 25 to 45 g per unit area (m ² ) of the fiber-reinforced cement board, and
^2. The decorative board according to 1, wherein the clear coating film has an organic solid content of 25 to 45 g per unit area (m ² ) of the fiber-reinforced cement board.

3. Applying an impregnation sealer to at least one side of the fiber-reinforced cement board, and curing the impregnation sealer;
On the impregnated sealer-treated surface, a method for producing a decorative board comprising a step of forming a surfacer coating film, an enamel coating film and a clear coating film in this order,
The said manufacturing method characterized by the said decorative board satisfy | filling all the following conditions (1)-(3).
(1) The fiber reinforced cement board has a thickness of 3 to 6.5 mm, an apparent density of 1.4 to 1.8 g / cm ³ , and a content ratio of pulp as a reinforcing fiber of 5 to 8 % By mass. (2) The total amount of organic solids contained in the impregnated sealer component, the surfacer coating component, the enamel coating component and the clear coating component is 63 per unit area (m ² ) of the fiber-reinforced cement board. ~ 130 g.
(3) The total calorific value of the decorative board is 8 MJ / m ² or less.

  According to the present invention, the thickness, apparent density, and pulp content ratio of the fiber reinforced cement board as the base material are within a specific range, and the organic solid content in the specific coating film formed on the surface thereof Thus, a decorative board having nonflammability and excellent surface smoothness, appearance, water resistance, weather resistance and handling properties and a method for producing the same could be provided.

It is sectional drawing of one Embodiment of the decorative board of this invention.

  Hereinafter, the present invention will be described in more detail. FIG. 1 is a cross-sectional view of one embodiment of the decorative board of the present invention. In FIG. 1, a decorative board 10 of the present invention is obtained by applying an impregnation sealer treatment 104 to one side of a fiber reinforced cement board 102 as a base material, and applying a surfacer coating 106, an enamel coating 108 and a clear coating on the impregnated sealer treatment surface. The film 110 is formed in this order. Hereinafter, a base material and each coating film are demonstrated.

(Fiber reinforced cement board)
As a fiber reinforced cement board used as a base material of a decorative board, a fiber material, hydraulic cement is used as an essential raw material, and various additives are used as a raw material as necessary. Examples include those produced by forming into a plate shape by a papermaking method, and further, after pressure forming as necessary, and curing by curing at room temperature, high temperature and high humidity (steam), or by autoclave curing.
As the curing method, autoclave curing is preferable because the dimensional stability is increased.
The fiber reinforced cement board has high frost damage resistance and mechanical properties, and is particularly suitably used as a base material for an exterior decorative board.

Examples of the fiber 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, pulp is used as an essential component.
In the fiber reinforced cement board, the content ratio of the pulp needs to be 5 to 8% by mass, and more preferably 6.5 to 7.5% by mass. If it is less than 5 mass%, the mechanical strength of the decorative board is lowered, and cracking due to heat load, drying, carbonation or impact tends to occur. Conversely, when it exceeds 8 mass%, it will become 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 an air-cementing cement such as gypsum because of a decrease in 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. When performing autoclave curing, siliceous raw materials, for example, crystalline silica such as powdered meteorite, amorphous silica such as fly ash, etc., because the strength is further increased by hydrothermal reaction hardening with lime in cement. Are preferably mixed and used as necessary.

  In the present invention, the thickness of the fiber reinforced cement board needs to be 3 to 6.5 mm. If it is less than 3 mm, the impact resistance is deteriorated, and the surface smoothness is impaired by the strain after the construction, which makes it particularly unsuitable as an exterior decorative board. Conversely, when it exceeds 6.5 mm, mass will increase, workability will fall, and it will also lead to a raise of cost. The thickness of the fiber reinforced cement board is more preferably 3.5 to 5.5 mm.

Moreover, in this invention, the apparent density of a fiber reinforced cement board needs to be 1.4-1.8 g / cm < ³ >. If it is less than 1.4 g / cm ³ , the surface of the base material becomes rough, and the appearance of the sealer is deteriorated, which deteriorates the appearance after painting. In addition, frost damage resistance is reduced, and mechanical properties such as rigidity and breaking load are reduced. When it exceeds 1.8 g / cm < ³ >, mass will increase and workability will fall. The apparent density of the fiber reinforced cement board is more preferably 1.5 to 1.7 g / cm ³ .

In the present invention, the total calorific value of the fiber-reinforced cement board is preferably equal to or less than 5 MJ / m ^2, and even more preferably 4.7MJ / m ² or less. If it exceeds 5 MJ / m ² , it is necessary to reduce the organic solid content in the impregnated sealer, surfacer coating, enamel coating and clear coating, and water resistance and weather resistance are desired. It becomes difficult to maintain at the level.

In the present invention, the thickness of the fiber-reinforced cement board or decorative board is a value measured according to JIS A 5430: 2008, 10.2.2 paragraph b).
The apparent density is a value measured according to JIS A 5430: 2008, 10.5.
The total calorific value is a value measured according to JIS A 5430: 2008, 10.9 paragraph b).

(Impregnation sealer treatment)
In the present invention, the impregnation sealer treatment is performed on the surface of the fiber reinforced cement board that is the base material of the decorative board. By performing the impregnating sealer treatment, the surface layer of the fiber reinforced cement board is strengthened, the elution of alkali to the surface can be prevented, and the adhesion with the surfacer coating film as an upper layer is also improved.
The impregnation sealer treatment can be performed using a known sealer, for example, by using a curable resin such as a moisture curable urethane resin or an epoxy resin, and applying and curing on the surface of the fiber reinforced cement board. Is called. The impregnation sealer has good impregnation into the fiber reinforced cement board, has a high non-volatile content, reacts with moisture in the fiber reinforced cement board and moisture in the atmosphere, and is three-dimensionally cross-linked, and has good water resistance etc. A moisture-curable urethane-based material mainly composed of a prepolymer having a free isocyanate group, which is a reaction product of a polyisocyanate and a polyol, 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 treatment can be performed, 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 3-10g per unit area (m < ² >) of the said fiber reinforced cement board. If it is less than 3 g, the surface layer of the fiber-reinforced cement board may not be strengthened so much. Moreover, there is a possibility that the adhesiveness with the surfacer coating film as the upper layer may be lowered. If it exceeds 10 g, excess organic solid content remains on the surface layer of the fiber reinforced cement board, and this organic solid layer may cause defects such as cohesive peeling in the sealer layer, foaming in the subsequent process, and aside. 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 3 to 8 g per unit area (m ² ) of the fiber reinforced cement board.

  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.

(Surfacer coating)
In the present invention, a surfacer coating film is formed on the impregnated sealer-treated surface. By forming a surfacer coating, large and small irregularities and voids on the surface of the fiber reinforced cement board are filled with paint, thereby suppressing irregularities and gloss / color variation due to paint suction spots. . In addition, the possibility of defects such as pinholes on the decorative board is reduced. Moreover, after forming a surfacer coating film, it is preferable to perform a grinding | polishing process. By performing the polishing treatment, the base becomes smooth and the design of each coating film formed thereon is not impaired, and a good appearance is provided.
The paint for forming the surfacer coating is preferably a paint containing a pigment at a high concentration, specifically, a two-component curable paint composed of components such as a pigment, an acrylic urethane resin, a solvent, and an additive. Can be used. Examples of the pigment include calcium carbonate and talc. These pigments are preferably contained in an amount of 30 to 35% by mass in the paint. Thereby, volume reduction after hardening of a coating material is prevented and polishability can also be improved. In addition, it is preferable to use a two-component curable coating material because the curing rate of the coating film can be controlled, so that separation of the pigment after coating can be prevented. After applying the paint, it is preferably cured to form a surfacer coating and then polished as described above. Examples of the application method include a method using a roll coater, a flow coater, etc. Among them, a roll coater is suitable in consideration of the effect of filling large and small uneven portions and voids on the surface of the fiber reinforced cement board with a paint. Yes. Apart from this, a flow coater is suitable from the viewpoint of applying the paint uniformly.

In this invention, it is preferable to set so that the amount of organic solids in the component of a surfacer coating film may be 10-30g per unit area (m < ² >) of the said fiber reinforced cement board. If it is less than 10 g, the wettability to the lower layer (fiber reinforced cement board) is lowered, and the adhesion may be lowered. Conversely, if it exceeds 30 g, foaming failure may occur after coating, or warpage may occur after drying. Moreover, the total calorific value increases, which may lead to deterioration of nonflammability. More preferably, the amount of organic solid content in the components of the surfacer coating film is set to 10 to ²⁰ g per unit area (m ² ) of the fiber reinforced cement board.

(Enamel coating)
In the present invention, an enamel coating film is formed on the surfacer coating film. The enamel coating film conceals the base color of the fiber-reinforced cement board as a base material, enables desired color addition, and can impart high designability.
Examples of the paint for forming the enamel coating film include inorganic pigments (for example, titanium yellow, graphite, etc.) having high concealability and weather resistance, acrylic resins, urethane resins or acrylic urethane resins, and other additives. Any known paint containing a wetting dispersant, an anti-settling agent, an antifoaming agent, a leveling agent, or the like, for example, butyl acetate, ethyl acetate or the like as a solvent may be used. The paint is preferably a two-component curable paint from the viewpoint of easily controlling the crosslinking reaction. As a method for applying the paint, a roll coater, a flow coater, or the like can be employed. For example, the temperature of the substrate can be heated to 50 to 60 ° C.

In this invention, it is preferable to set so that the amount of organic solids in the component of an enamel coating film may become 25-45g per unit area (m < ² >) of the said fiber reinforced cement board. If it is less than 25g, the said concealment property may deteriorate. On the other hand, if it exceeds 45 g, the total calorific value may increase and the nonflammability may decrease. In addition, poor foaming may occur after painting, which may impose restrictions on drying conditions. The organic solid content in the enamel coating component is more preferably set to be 25 to 35 g per unit area (m ² ) of the fiber reinforced cement board.

(Clear film)
In the present invention, a clear coating film is formed on the enamel coating film. The clear coating film functions as a protective layer and contributes to improvement of weather resistance. By using a matte additive in the clear coating and suppressing the surface gloss, it is possible to achieve a calm finish.
The paint for forming the clear coating film is not particularly limited. For example, a colorless transparent resin composed of a two-component curable resin such as acrylic silicone, urethane, or acrylic, a thermosetting resin, or the like Examples include a translucent resin containing a matting agent in the resin, and other additives such as a wetting and dispersing agent, an anti-settling agent, an antifoaming agent, and a leveling agent, and those containing, for example, butyl acetate and ethyl acetate as solvents. It is done. Among them, it is preferable to use an acrylic silicone resin that is excellent in weather resistance and stain resistance. In the present invention, the term “transparent or translucent” 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. 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 amount of organic solids in the component of a clear coating film may become 25-45g per unit area (m < ² >) of the said fiber reinforced cement board. If it is less than 25 g, the weather resistance may be lowered. On the other hand, if it exceeds 45 g, the total calorific value may increase and the nonflammability may decrease. In addition, the cost increases, the drying property decreases, and defects such as cracks may occur after the coating film is cured. More preferably, the organic solid content in the components of the clear coating film is set to 25 to 35 g per unit area (m ² ) of the fiber reinforced cement board.

In the present invention, the total amount of organic solids contained in the impregnated sealer component, the surfacer coating component, the enamel coating component and the clear coating component is 63 per unit area (m ² ) of the fiber reinforced cement board. Must be ~ 130g. If it is less than 63 g, the appearance, water resistance, weather resistance and handling properties that are the effects of the present invention cannot be satisfied at the same time. Moreover, when it exceeds 130 g, nonflammability may deteriorate and the external appearance after coating may deteriorate. Therefore, in order to provide a decorative board that has both performances such as weather resistance and appearance properties conventionally required for a decorative board and non-flammability, which is the opposite of the performance, It is necessary to set to 63 to 130 g per unit area (m ² ) of the reinforced cement board. A more preferable total amount of organic solids is 63 to 85 g.

  The decorative board of the present invention comprises a step of applying an impregnation sealer treatment to at least one surface of a fiber reinforced cement board and curing the impregnation sealer, and a surfacer coating film, an enamel coating film and a clear coating film on the impregnation sealer treatment surface. Forming in this order. The method for forming each coating film 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. 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.

Manufacture of fiber-reinforced cement board (base material) Raw material pulp: Canadian bleached kraft pulp (N-BKP)
Cement: Ordinary Portland cement powder manufactured by Taiheiyo Cement Co., Ltd .: Chichibu Mining Co., Ltd. (powder degree 3000 m ² / g)
Pulverized powder: pulverized product of fiber reinforced cement board Calcium carbonate: TM No. 1 Wollastonite manufactured by Yuesu Mining Co., Ltd .: KTP-N01 manufactured by Kansai Matec
Mica: SG-MU100 manufactured by Asahi Minesuesha

  Each raw material shown above was added and mixed with each compounding amount (mass%) shown in Table 1 to obtain a raw material slurry. Each of these raw material slurries was made with a round net-type paper making machine, and then pressed between the steel plates so as to have a predetermined thickness to obtain green plates. After surface pressing, the raw plate and the iron plate were separated and stacked, and then steam curing was performed at 60 ° C. for 1 hour and 30 minutes as a primary curing, followed by autoclave curing at 165 ° C. for 15 hours. Then, the fiber reinforced cement board which is a base material of a decorative board was obtained by drying.

Coating Each coating was formed using the following paint.
Impregnation sealer: A one-pack type urethane resin impregnation sealer was used. As a thinner, urethane thinner SE manufactured by Chugoku Paint Co., Ltd. was used, the dilution ratio was 1 to 2 times, and the organic solid content at that time was 15 to 25% by mass.
Surfacer coating film-forming paint: A two-component acrylic urethane resin paint was used. The blending mass ratio is acrylic urethane-based resin: urethane-based curing agent: thinner (retarder thinner manufactured by China Paint Co., Ltd.) = 16: 1: 3-4, and the organic solid content at that time is 16.5-17.5% by mass. It was.
Enamel coating film-forming paint: A two-component acrylic urethane resin paint was used. The blending mass ratio is acrylic urethane-based resin paint: urethane-based curing agent: thinner (retarder thinner manufactured by China Paint Co., Ltd.) = 8: 1: 0.5 to 0.7, and the organic solid content at that time is 26.0. The content was 27.0% by mass.
Clear film-forming paint: A two-component acrylic silicone resin paint was used. The blending mass ratio is acrylic silicone resin: curing agent: thinner (urethane thinner SE manufactured by China Paint Co., Ltd.) = 10: 1: 0.6 to 1.0, and the organic solid content at that time is 31.0 to 32. The content was 0% by mass.

Example 1
First, the base material having a thickness of 5.0 mm and an apparent density of 1.6 g / cm ³ prepared above was heated to 50 to 60 ° C. with a pre-heater, and then the impregnation sealer was applied with a roll coater to a coating amount of 20 g / m ^2. The coating was applied so that the organic solid content was 4.0 g / m ^2, and the reaction was cured by moisture in the substrate. Subsequently, the paint for forming the surfacer coating film is first coated with a roll coater so that the coating amount becomes 20 g / m ² (organic solid content: 3.5 g / m ² ), and further, the coating amount is applied with a flow coater. Was 60 g / m ² (organic solid content 10.0 g / m ² ). Then, after forming a coating film by normal temperature drying, the coating film was grind | polished with the buff grinder and the surfacer coating film was formed. Polishing was performed first with # 320 and then with # 1000. The organic solid content of the surfacer coating after polishing was 11.5 g / m ² . The organic solid content of the surfacer coating after polishing was calculated from the rate of decrease in the thickness of the coating before and after polishing. That is, since the coating thickness before polishing was 26 μm and the coating thickness after polishing was 22 μm, the reduction rate of the coating thickness was 15%. Therefore, the organic solid content after polishing was 13.5 × (1−0.15) = 11.5 g / m ² . Next, on the surface of the surfacer coating film, an enamel coating film-forming paint is first applied with a roll coater so that the coating amount is 20 g / m ² (organic solid content: 5.4 g / m ² ), and further on it. After coating with a flow coater such that the coating amount was 80 g / m ² (organic solid content: 20.8 g / m ² ), the coating was dried at 70 ° C. for 2 minutes using a jet dryer to form an enamel coating film. Subsequently, after applying the clear coating film-forming coating on the surface of the enamel coating film with a flow coater so that the coating amount becomes 80 g / m ² (organic solid content: 25.2 g / m ² ), first, the coating is first carried out at 80 ° C. The film was dried for 20 minutes, and further dried at 50 ° C. for 20 minutes to form a clear coating film to produce a decorative board.

Example 2
A base material having a pulp content of 7.0% by mass and a calcium carbonate content of 26.0% by mass was used, and an impregnated sealer was applied with a roll coater to a coating amount of 40 g / m ² (organic solid content: 8. 0g / m ² ), and the paint for forming the surfacer coating film is applied with a roll coater so that the coating amount is 20 g / m ² (organic solid content: 3.5 g / m ² ). The coating amount is 80 g / m ² (organic solid content: 13.3 g / m ² ) with a coater, and the polished surfacer coating has an organic solid content of 14.5 g / m ^2. The forming coating is applied with a roll coater so that the coating amount is 20 g / m ² (organic solid content: 5.3 g / m ² ), and further, the coating amount is 100 g / m ² (organic solid content: 26 with a flow coater). .5g / m ²⁾ to become Painted, clear paint film-forming coating material to the coating amount is 20 g / m ² (organic solid content: 6.3g / m ²⁾ by a roll coater and was coated so that further flow coater in the coating amount is 80 g / m ^{2 A} decorative board was produced under the same conditions as in Example 1 except that coating was performed so that the organic solid content was 25.2 g / m ² .

Example 3
Amount pulp is 5.0%, the amount thickness at 28.0 wt% calcium carbonate using the substrate is 3 mm, the coating amount of the impregnating sealer by a roll coater 40 g / m ² (organic (Solid content: 8.0 g / m ² ) and coated with a surface coater coating composition with a roll coater so that the coating amount is 40 g / m ² (organic solid content: 6.8 g / m ² ). The coating was further applied with a flow coater so that the coating amount was 160 g / m ² (organic solid content: 27.2 g / m ² ), and the organic solid content of the surfacer coating after polishing was 28.9 g / m ^2. Then, the enamel coating film-forming paint is applied with a roll coater so that the coating amount is 40 g / m ² (organic solid content: 10.6 g / m ² ), and further, the coating amount is 120 g / m ² ( Organic solid content: 31.8 / M ²⁾ and was applied so that, clear paint film-forming coating material a coating weight of 20 g / m ² (organic solid content in a roll coater: 6.3g / m ²⁾ and was applied so that further flow coater A decorative board was produced under the same conditions as in Example 1 except that the coating amount was 120 g / m ² (organic solid content: 37.8 g / m ² ).

Example 4
A decorative board was produced under the same conditions as in Example 1 except that a substrate having an apparent density of 1.45 g / cm ³ was used.

Example 5
Using a base material with an apparent density of 1.75 g / cm ³ , paint the surfacer coating film with a flow coater so that the coating amount is 60 g / m ² (organic solid content: 10.2 g / m ² ). and organic solid content of the surfacer coating after polishing and 8.7 g / m ^2, the coating amount of the enamel coating the coating material for forming a roll coater 20 g / m ² (organic solid content: 5.3g / m ²⁾ Furthermore, the coating amount is 100 g / m ² (organic solid content: 26.5 g / m ² ) with a flow coater, and the coating amount for the clear coating film is applied with a roll coater. A decorative board was produced under the same conditions as in Example 1 except that the coating was applied so as to be 70 g / m ² (organic solid content: 22.1 g / m ² ).

Example 6
Amount pulp is 5.0%, the amount thickness at 28.0 wt% calcium carbonate using the substrate is 3 mm, the coating amount of the impregnating sealer by a roll coater 10 g / m ² (organic (Solid content: 2.0 g / m ² ) and coated with a surface coater coating composition using a roll coater so that the coating amount is 40 g / m ² (organic solid content: 6.8 g / m ² ). The coating was further applied with a flow coater so that the coating amount was 160 g / m ² (organic solid content: 27.2 g / m ² ), and the organic solid content of the surfacer coating after polishing was 28.9 g / m ^2. The enamel coating film-forming paint was applied with a roll coater so that the coating amount was 40 g / m ² (organic solid content: 10.6 g / m ² ), and further, the coating amount was 140 g / m ² ( Organic solid content: 37.1 / M ²⁾ and was applied so that, clear paint film-forming coating material to the coating amount is 80 g / m ² (organic solid content in flow coater: 25.2g / m ²⁾ and except for painting so that the embodiment 1 A decorative board was produced under the same conditions as those described above.

Comparative Example 1
The paint for forming the surfacer coating film is applied only with a roll coater so that the coating amount is 30 g / m ² (organic solid content: 5.3 g / m ² ), and the organic solid content of the surfacer coating after polishing is 4. A decorative board was produced under the same conditions as in Example 1 except that the amount was 1 g / m ² .

Comparative Example 2
The paint for forming the surfacer coating film is applied with a roll coater so that the coating amount is 40 g / m ² (organic solid content: 6.8 g / m ² ), and further, the coating amount is 180 g / m ² (organic solid) with a flow coater. content: 30.6g / m ²⁾ and was applied so that, except for organic solid content of the surfacer coating after polishing became 31.8 g / m ² by the same conditions as in example 1, producing a veneer did.

Comparative Example 3
Amount pulp is 5.0%, the amount thickness at 28.0 wt% calcium carbonate using the substrate is 3 mm, the coating amount is 60 g / m ² (organic impregnation sealer by a roll coater (Solid content: 12.0 g / m ² ) and coated with a surface coater coating composition with a roll coater so that the coating amount is 60 g / m ² (organic solid content: 10.2 g / m ² ). The coating was further applied with a flow coater so that the coating amount was 120 g / m ² (organic solid content: 20.4 g / m ² ), and the organic solid content of the surfacer coating after polishing was 22.1 g / m ^2. The enamel coating film-forming paint was applied with a roll coater so that the coating amount was 60 g / m ² (organic solid content: 15.9 g / m ² ), and further, the coating amount was 120 g / m ² ( Organic solid content: 31 8 g / m ²⁾ and was applied so that, clear paint film-forming coating material to the amount of coating rubber roll coater 40 g / m ² (organic solid content: 12.6g / m ²⁾ and was applied so that further flow A decorative board was produced under the same conditions as in Example 1 except that the coating amount was 120 g / m ² (organic solid content: 37.8 g / m ² ) with a coater.

Comparative Example 4
A decorative board was produced under the same conditions as in Example 1 except that a pulp blending amount of 8.0% by mass, a calcium carbonate blending amount of 25.0% by mass and a thickness of 5 mm were used.

Comparative Example 5
A decorative board was produced under the same conditions as in Example 1 except that a substrate having an apparent density of 1.35 g / cm ³ was used.

Comparative Example 6
A decorative board was produced under the same conditions as in Example 1 except that a base material containing 4.5% by mass of pulp and 28.5% by mass of calcium carbonate was used.

Comparative Example 7
A decorative board was produced under the same conditions as in Example 1 except that a substrate having a thickness of 2.5 mm was used.

Comparative Example 8
A decorative board was produced under the same conditions as in Example 1 except that a substrate having an apparent density of 1.9 g / cm ³ was used.

Evaluation The following evaluation was performed about each obtained decorative board.
1. Apparent density: Measured according to JIS A 5430: 2008, 10.5.
2. Total calorific value: Measured according to JIS A 5430: 2008, 10.9 paragraph b).
・ Test equipment: Corn calorimeter 3 from Toyo Seiki Seisakusho Co., Ltd.
・ Measure the total calorific value after heating for 20 minutes.
-The total calorific value of the coating film was measured by using a stainless steel plate as a base instead of the base material and coating each paint.
-As evaluation criteria, the thing whose total calorific value of a decorative board is 8.0 MJ / m < ² > or less was made into (circle), and the thing exceeding 8.0 MJ / m < ² > was made into x.
3. Water resistance: In accordance with JIS K 5600-6-2 liquid resistance (water immersion method), immersed in water at 40 ° C. for 30 days, dried at 60 ° C. for 24 hours, allowed to cool to room temperature, and then adhered. It was evaluated by testing. The adhesion test was based on the adhesion (cross-cut method) of JIS K 5600-5-6, the number of cuts was 5 in each direction of the lattice pattern, and the interval between the cuts was 4 mm. As evaluation criteria, among the 16 squares, those having no deficiency were marked with ◯, those with 1 to 3 deficiencies were marked with Δ, and those with 4 or more deficiencies were marked with ×. In addition, about 1 mass, what peeled the area of 50% or more was handled as a defect mass.
4). The weather resistance was evaluated by observing the appearance after 1000 hours of the test using an accelerated weather resistance tester (Isuperki UV Tester UV-W231 manufactured by Iwasaki Electric Co., Ltd.). The test conditions were a metal halide lamp with an irradiance of 75 mW / cm ² as a light source, and the irradiation was repeated for 4 hours → no irradiation for 4 hours (with watering). As evaluation criteria, a color difference (ΔE ^* ab) on the decorative surface before and after the test is 1 or less, and there is no cracking, swelling, peeling, choking (reduction of pigments contained in the enamel coating film), etc. A sample having a color difference exceeding 1 but 3 or less and having no cracking, swelling, peeling, choking, etc. was marked with Δ, and a sample having a color difference exceeding 3, or having cracking, swelling, peeling, choking, etc.
5. As an evaluation standard for the appearance after painting, when the surface is observed using a 10-fold magnifier, the foam marks and cracks are not confirmed at all, and the foam is slightly observed but the cracks are not confirmed at all. Δ, the case where foaming and cracks were clearly seen was marked with ×.
6). The evaluation criteria for handling ability are that the decorative board can be handled by itself without any problems, and those that do not cause defects such as chipping or cracking during construction, the decorative board is heavy or thin, etc. Although it is possible to handle by itself, it is difficult to handle, and it is difficult to handle because it is not easy to handle due to chipping or cracking during construction, because the decorative board is very heavy or very thin In the construction, x indicates a chip that causes a defect such as chipping or cracking.
7). The appearance after the construction was evaluated by observing the surface state of the decorative board after the adhesive was cured after the decorative board was attached to the base by an adhesive method using an adhesive and a double-sided tape. As the evaluation criteria, the case where there was no change from before construction was indicated as ◯, the case where slight distortion or undulation was observed was indicated as △, and the case where obvious distortion or undulation was observed was indicated as x.
The results are shown in Table 1.

The decorative boards of Examples 1 to 6 have specific thicknesses that are formed on the surface of the fiber-reinforced cement board as a base material, the thickness, the apparent density, and the pulp content ratio within the range defined by the present invention. Since the total amount of organic solids in the coating film was set within the range specified in the present invention, it was found that it has nonflammability and is excellent in surface smoothness, appearance, water resistance, weather resistance and handling properties. .
On the other hand, in the decorative board of Comparative Example 1, the total amount of organic solids contained in the impregnated sealer component, the surfacer coating component, the enamel coating component and the clear coating component is the unit of the fiber reinforced cement plate. Since it was 60 g per area (m ² ) and out of the scope of the present invention, the water resistance deteriorated.
The decorative board of Comparative Example 2 could not acquire nonflammability because the total calorific value of the decorative board exceeded 8.0 MJ / m ² . Moreover, since the total amount of organic solids contained in the components of the surfacer coating film is 31.8 g per unit area (m ² ) of the fiber reinforced cement board, which is outside the scope of the present invention, the appearance after coating is also deteriorated. did.
In the decorative board of Comparative Example 3, the total amount of organic solids contained in the impregnated sealer component, the surfacer coating component, the enamel coating component and the clear coating component is the unit area (m ² ) Was 132 g per unit, which is outside the scope of the present invention, so that nonflammability could not be obtained. In addition, the appearance after painting deteriorated.
The decorative board of Comparative Example 4 could not acquire nonflammability because the total calorific value of the decorative board exceeded 8.0 MJ / m ² .
In the decorative board of Comparative Example 5, the apparent density of the base material was 1.35 g / cm ³ , which was outside the scope of the present invention, so that the appearance after painting deteriorated.
Since the decorative board of Comparative Example 6 had a pulp content of 4.5% and was outside the scope of the present invention, the appearance after coating deteriorated.
Since the decorative board of Comparative Example 7 has a base material thickness of 2.5 mm and is outside the scope of the present invention, handling properties and appearance after construction deteriorated.
The decorative board of Comparative Example 8 had an apparent density of 1.9 g / cm ^{3 and} was outside the scope of the present invention, so the handling properties were deteriorated.

Claims (3)

At least one surface of the fiber reinforced cement board is subjected to an impregnation sealer treatment, and a surfacer coating film, an enamel coating film and a clear coating film are formed in this order on the impregnation sealer processing surface, and the following conditions (1) to (3 ), A decorative board characterized by satisfying all of
(1) The fiber reinforced cement board has a thickness of 3 to 6.5 mm, an apparent density of 1.4 to 1.8 g / cm ³ , and a content ratio of pulp as a reinforcing fiber of 5 to 8 % By mass. (2) The total amount of organic solids contained in the impregnated sealer component, the surfacer coating component, the enamel coating component and the clear coating component is 63 per unit area (m ² ) of the fiber-reinforced cement board. ~ 130 g.
(3) The total calorific value of the decorative board is 8 MJ / m ² or less. The amount of organic solid in the component of the impregnated sealer is 3 to 10 g per unit area (m ² ) of the fiber-reinforced cement board,
The organic solid content of the surfacer coating film is 10 to 30 g per unit area (m ² ) of the fiber reinforced cement board,
An organic solid content of the enamel coating film is 25 to 45 g per unit area (m ² ) of the fiber-reinforced cement board, and
^2. The decorative board according to claim 1, wherein the clear solid coating has an organic solid content of 25 to 45 g per unit area (m ² ) of the fiber-reinforced cement board. Applying an impregnation sealer to at least one side of the fiber-reinforced cement board, and curing the impregnation sealer;
On the impregnated sealer-treated surface, a method for producing a decorative board comprising a step of forming a surfacer coating film, an enamel coating film and a clear coating film in this order,
The said manufacturing method characterized by the said decorative board satisfy | filling all the following conditions (1)-(3).
(1) The fiber reinforced cement board has a thickness of 3 to 6.5 mm, an apparent density of 1.4 to 1.8 g / cm ³ , and a content ratio of pulp as a reinforcing fiber of 5 to 8 % By mass. (2) The total amount of organic solids contained in the impregnated sealer component, the surfacer coating component, the enamel coating component and the clear coating component is 63 per unit area (m ² ) of the fiber-reinforced cement board. ~ 130 g.
(3) The total calorific value of the decorative board is 8 MJ / m ² or less.

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