JP6239958B2 - Decorative building board - Google Patents

Description

  The present invention relates to a decorative building board obtained by painting a base material.

  Conventionally, a decorative building board obtained by coating a base material has been widely used as an outer wall material. The decorative building board is colored to express the design. Further, a clear layer is formed on the colored layer in order to protect the colored layer formed by the colored coating.

  A decorative building board is exposed to ultraviolet rays for a long time because of its use. When the colored layer is irradiated with ultraviolet rays for a long time, the colored layer is discolored and faded. For this reason, an ultraviolet absorber is contained in the clear layer on the colored layer (see, for example, FIG. 2 of Patent Document 1).

Japanese Patent Laid-Open No. 10-230213

  As described above, the color of the coating film has been originally maintained for a long time when the base material is applied.

  However, discoloration of the coating film inevitably occurs, and no attempt has been made to effectively utilize this discoloration.

  This invention is made | formed in view of said point, It aims at providing the decorative building board provided with the colored coating film and can utilize effectively the discoloration of this coating film. It is.

Decorative building board according to the present onset Ming, a decorative building board obtained by performing a coating to a substrate,
A colored coating film containing an organic pigment and a photocatalytic material is provided .
On the base material, a colored layer, the colored coating film, and an organic clear layer are sequentially laminated,
The colored coating film covers a part of the colored layer .

Repainting timing determination method according to the present onset Ming, said a repainting timing determination method of the organic clear layer, and the permissible range of color values of the colored coating in cosmetic building board according to the second embodiment,
Measure the color value of the colored coating film,
When the color value of the colored coating film is within the allowable range, it is determined that repainting of the organic clear layer is unnecessary,
When the color value of the colored coating film is outside the allowable range, it is determined that the organic clear layer needs to be repainted.

  In the present invention, since the colored coating film contains an organic pigment and a photocatalytic material, discoloration of the colored coating film is promoted, and this discoloration color can be effectively utilized.

1 is a schematic cross-sectional view showing a first embodiment of the present invention. It is a schematic sectional drawing which shows 2nd embodiment of this invention. 6 is a graph showing the results of Test 1. 6 is a graph showing the results of Test 2.

  A decorative building board 1 according to the present invention is a decorative building board 1 obtained by painting a base material 11, and includes a colored coating film 13 containing an organic pigment and a photocatalytic material.

  In the decorative building board 1, the colored layer 12, the colored coating film 13, and the organic clear layer 14 are sequentially laminated on the base material 11, and the colored coating film 13 covers a part of the colored layer 12.

  In the decorative building board 1, the organic layer 15, the inorganic layer 16, and the colored coating film 13 may be sequentially laminated on the base material 11.

  The method for determining the repainting time of the organic clear layer 14 in the decorative building board 1 is to set the allowable range of the color value of the colored coating film 13, measure the color value of the colored coating film 13, and When the color value is within the allowable range, it is determined that repainting of the organic clear layer 14 is unnecessary, and when the color of the colored coating film 13 is out of the allowable range, repainting of the organic clear layer 14 is necessary. Is determined.

  Hereinafter, modes for carrying out the present invention will be described.

  The decorative building board 1 of 1st embodiment is equipped with the base material 11 and the colored coating film 13 as shown in FIG.

  The decorative building board 1 may further include one or more layers other than the colored coating film 13. In the present embodiment, a sealer coating 11 a and a colored layer 12 are sequentially laminated between the base material 11 and the colored coating 13. An organic clear layer 14 is formed on the colored coating film 13.

  The base material 11 is obtained, for example, by blending an inorganic filler, a fibrous material, or the like with a hydraulic glue used as a raw material for an inorganic cured body, and curing and curing it after molding. The hydraulic glue is not particularly limited, but can contain, for example, one or more materials selected from the group consisting of Portland cement, blast furnace cement, blast furnace slag, calcium silicate, and gypsum. The inorganic filler can contain, for example, one or more materials selected from the group consisting of fly ash, microsilica, and silica sand. The fibrous material can contain, for example, one or more materials selected from the group consisting of inorganic fibers such as pulp and synthetic fibers, and metal fibers such as steel fibers. The molding method is selected from, for example, extrusion molding, cast molding, papermaking molding, press molding, and the like. After the ceramic base material 11 is molded, autoclave curing, steam curing, room temperature curing, or the like is performed as necessary. In addition, the base material 11 may be selected from, for example, inorganic boards such as flexible boards, calcium silicate boards, gypsum slag perlite boards, wood chip cement boards, precast concrete boards, ALC boards, and gypsum boards.

  The sealer coating film 11 a is formed on the surface of the base material 11, and secures adhesion when the surface of the base material 11 has irregularities and the like and adhesion between the base material 11 and the colored layer 12.

  The sealer coating 11a is formed from a sealer paint. As the sealer coating, it is possible to use a permeable type undercoat made of a low molecular weight resin or an emulsion having a small particle diameter. Specifically, for example, an acrylic emulsion resin is prepared by adding a pigment such as titanium oxide, iron oxide pigment, carbon black, calcium carbonate, an organic solvent, an additive such as an antifoaming agent, water, etc., and stirring and dispersing. Sealed paint can be used.

The sealer coating film 11a is formed, for example, by applying a sealer paint on the surface of the substrate 11 and baking and drying. The application method of the sealer paint is selected from, for example, a spray gun, a roll coater, a flow coater, a curtain coater and the like. The coating amount of the sealer coating is preferably in the range of 50~170g / ^{m 2.} It is preferable to bake and dry the sealer paint at 80 to 120 ° C. for 1 to 3 minutes.

  The colored layer 12 is formed from, for example, an acrylic resin-based paint (hereinafter referred to as a colored paint). In particular, the colored paint is preferably an acrylic resin-based enamel paint that has a high base hiding power, excellent durability, has a wide variety of colors, and can contribute to an improvement in appearance design. Specifically, for example, an organic pigment and / or an inorganic pigment, an organic solvent, an antifoaming agent, an additive such as a thickener, water, etc. are added to an acrylic emulsion resin or an acrylic silicone emulsion resin, and the mixture is stirred and dispersed. The enamel paint prepared in this way can be used.

  When the colored paint is an enamel paint, it may contain a pigment. The pigment may be an organic pigment or an inorganic pigment or both. Examples of the organic pigments include rhodamine lake, methyl violet lake, quinoline yellow lake, malachite green lake, alizarin lake, carmine 6B, lakelet C, disazo yellow, lakelet 4R, chromophthal yellow 3G, chromophthal scarlet RN, nickel azo yellow, permanent. From the group consisting of Orange HL, Phthalocyanine Blue, Phthalocyanine Green, Flavanthrone Yellow, Thioindigo Bordeaux, Perinone Red, Dioxadone Violet, Quinacridone Red, Naphthol Yellow S, Pigrant Green B, Lumogen Yellow, Signal Red, Alkaline Blue and Aniline Black One or more selected materials may be included. In addition, the inorganic pigment can contain, for example, one or more materials selected from the group consisting of calcium carbonate, titanium oxide (titanium white), bitumen, ultramarine, iron oxide, aluminum paste, bronze powder, and carbon black. .

The colored layer 12 is formed, for example, by applying a colored paint on the surface of the sealer coating film 11a and then baking and drying as necessary. The method for applying the colored paint is selected from the group consisting of inkjet, spray gun, roll coater, flow coater, and curtain coater, for example. When the colored paint is applied by inkjet, a receiving layer may be formed as necessary. The coating amount of the colored coating material is preferably in the range of 75~140g / ^{m 2.} Baking and drying of the applied colored paint is preferably performed, for example, at 80 to 120 ° C. for 1 to 3 minutes using a jet dryer.

  In the present embodiment, the colored coating film 13 is formed on the surface of the colored layer 12 and covers a part of the colored layer 12.

  The colored coating film 13 is formed from a colored coating film paint. The colored coating film contains an organic pigment and a photocatalytic material. In particular, the colored coating film paint is preferably an acrylic resin-based enamel paint containing an organic pigment and a photocatalytic material. Specifically, for example, an organic pigment and a photocatalyst material are blended into an acrylic emulsion resin or an acrylic silicone emulsion resin, and further, an organic solvent, an antifoaming agent, a thickener and other additives, water, etc. In addition, an enamel paint prepared by stirring and dispersing can be used as a colored coating film.

  Examples of the organic pigments include rhodamine lake, methyl violet lake, quinoline yellow lake, malachite green lake, alizarin lake, carmine 6B, lakelet C, disazo yellow, lakelet 4R, chromophthal yellow 3G, chromophthal scarlet RN, nickel azo yellow, permanent. From the group consisting of Orange HL, Phthalocyanine Blue, Phthalocyanine Green, Flavanthrone Yellow, Thioindigo Bordeaux, Perinone Red, Dioxadone Violet, Quinacridone Red, Naphthol Yellow S, Pigrant Green B, Lumogen Yellow, Signal Red, Alkaline Blue and Aniline Black One or more selected materials may be included. The photocatalytic material can contain, for example, one or more materials selected from the group consisting of titanium oxide, zinc oxide, cadmium sulfide, and tungsten oxide.

  When the colored paint used for forming the colored layer 12 contains an organic pigment, a paint prepared by adding a photocatalytic material to the colored paint may be used as the colored coating film. In this case, a difference in color between the colored layer 12 and the colored coating film 13 hardly occurs.

The colored coating film 13 is formed, for example, by applying a colored coating film coating on the surface of the colored layer 12 and baking and drying. The coating method of the colored coating film paint is selected from coating methods that can be applied to any location of the colored layer 12. The method for applying the colored coating film is selected from the group consisting of, for example, a spray gun, a roll coater, a flow coater, and a curtain coater. The coating amount of the colored coating paint is preferably in the range of 50~140g / ^{m 2.} Baking and drying of the applied colored coating film is preferably performed, for example, at 80 to 120 ° C. for 1 to 3 minutes using a jet dryer.

  The position and size of the colored coating film 13 are preferably determined so that the colored coating film 13 is not conspicuous in the appearance of the decorative building board 1. Specifically, for example, the colored coating film 13 is formed by applying a very small amount of a colored coating film paint to a small region on the surface of the colored layer 12, and then baking and drying. The application area is preferably in the range of about 1 cm × 1 cm.

  Since the colored coating film 13 contains a photocatalytic material, when the colored coating film 13 is irradiated with light, the action of the photocatalytic material promotes the oxidation of the organic pigment in the colored coating film 13. For this reason, compared with the colored layer 12 which does not contain a photocatalytic material, the discoloration of the colored coating film 13 proceeds very quickly.

  It is preferable that the colored coating film 13 contains a photocatalyst material in the range of 1 to 10% by mass. When the content of the photocatalytic material is 1% by mass or more, the organic pigment is easily oxidized. When the content of the photocatalytic material is 10% by mass or less, the colored coating film 13 is hardly peeled off from the colored layer 12.

  The organic clear layer 14 is formed by applying an organic clear coating on the surface of the colored layer 12 and the colored coating film 13. The organic clear paint is selected from, for example, an acrylic resin paint, an acrylic silicon resin paint, and a fluorine resin paint. The organic clear paint preferably contains an ultraviolet absorber. As the ultraviolet absorber, for example, a benzotriazole ultraviolet absorber can be used. For example, the organic clear coating is prepared by adding a benzotriazole ultraviolet absorber to an acrylic resin coating.

The organic clear layer 14 is formed, for example, by applying an organic clear coating on the surface of the colored layer 12 and the colored coating film 13 and then baking and drying. The method for applying the organic clear paint is selected from, for example, a spray gun, a roll coater, a flow coater, a curtain coater, and the like. At this time, the coating amount of the organic clear coating is preferably within a range of 40 to 100 g / m ² . The organic clear coating is preferably baked and dried at 80 to 120 ° C. for 60 seconds or longer.

  In the decorative building board 1 formed as described above, initially, the organic clear layer 14 protects the colored layer 12 and the colored coating film 13, and these fading colors are unlikely to occur. However, when this decorative building board 1 is used over a long period of time, the organic clear layer 14 is worn out and deteriorates over time. If it does so, especially the colored coating film 13 contains a photocatalyst material, Therefore A discoloration color arises in the time earlier than the colored layer 12. FIG.

  When this effect is utilized, the user of the decorative building board 1 measures the color value of the colored coating film 13 and determines whether or not the colored coating film 13 is discolored, thereby determining the organic clear layer 14. The degree of deterioration can be determined. After the user determines that the organic clear layer 14 has deteriorated over time, the discoloration of the colored layer 12 can be prevented beforehand by repainting the organic clear layer 14.

  The method for determining the repainting time of the organic clear layer 14 in the decorative building board 1 according to the present embodiment will be described in detail.

  In this re-coating time determination method, an allowable range of color values of the colored coating film 13 is set, a color value of the colored coating film 13 is measured, and the color value of the colored coating film 13 is within the allowable range. In this case, it is determined that repainting of the organic clear layer 14 is unnecessary, and when the color value of the colored coating film 13 is outside the allowable range, it is determined that repainting of the organic clear layer 14 is necessary.

As the color specification value, an appropriate value that can serve as an index of color change of the colored layer 12 and the colored coating film 13 is selected. For example, the color difference from the standard color is selected as the color specification value. Examples of the standard color include the color of the colored coating film 13 in a state in which no discoloration occurs. The color difference (ΔL ^* ) is defined by the following equation, for example.
ΔL ^* = L ^* _1- L ^* ₀
L ^* ₀ is the L ^* value of the standard color of the colored coating film 13. Here, L ^* is the L ^* value of the L ^* a ^* b ^* color system defined in JIS Z 8729. The measurement time of the color specification value of the standard color is not particularly limited as long as no discoloration occurs in the colored coating film 13. L ^* ₁ is the L ^* value of the colored coating film 13 in which the discoloration has progressed.

In this embodiment, the color difference is ΔL ^* , but is not limited thereto, and may be ΔE ^* , for example.

  The allowable range of the color value is appropriately specified according to the configuration of each layer. Specifically, for example, the accelerated weather resistance test of the decorative building board 1 is performed, and the colored coating film 13 in a state where the colored layer 12 of the decorative building board 1 does not discolor and the discoloration of the colored coating film 13 occurs. The color value is measured, and this value is set as the allowable threshold value.

  In determining the repainting time of the organic clear layer 14, the user installs the decorative building board 1 outdoors and measures the color value of the colored coating film 13 regularly or irregularly. If the color value is within the allowable range, the user determines that repainting of the organic clear layer 14 is unnecessary, and continues to measure the color value.

  If the color value is outside the allowable range, the user determines that the organic clear layer 14 has deteriorated over time and needs to be repainted. In this case, the user can prevent discoloration of the colored layer 12 by recoating the organic clear layer 14.

  Next, a second embodiment of the decorative building board 1 will be described.

  In the decorative building board 1 of this embodiment, as shown in FIG. 2, an organic layer 15, an inorganic layer 16, and a colored coating film 13 are sequentially laminated on a base material 11. The colored coating film 13 contains an organic pigment and a photocatalytic material.

  The decorative building board 1 may further include one or more layers other than the organic layer 15, the inorganic clear layer 17, and the colored coating film 13. In the present embodiment, a sealer coating film 11 a is formed between the base material 11 and the organic layer 15. In addition, an inorganic clear layer 17 is formed on the colored coating film 13.

  As the base material 11 and the sealer coating film 11a, the same materials as the base material and the sealer coating film of the decorative building board 1 according to the first embodiment can be used.

  The organic layer 15 is formed from an organic paint (hereinafter referred to as an organic paint). The organic paint is preferably an acrylic resin-based enamel paint that has a high foundation hiding power, is excellent in durability, has a wide variety of colors, and can contribute to improvement in appearance design. Specifically, for example, pigments such as titanium oxide, iron oxide pigments, carbon black, barium sulfate, organic solvents, antifoaming agents, thickeners and other additives to acrylic emulsion resins and acrylic silicone emulsion resins, An organic paint prepared by adding water or the like and stirring and dispersing can be used.

The organic layer 15 is formed, for example, by applying an organic paint on the surface of the sealer coating 11a and baking and drying. The coating method of the organic paint is selected from, for example, a spray gun, a roll coater, a flow coater, a curtain coater and the like. At this time, the coating amount of the organic paint is preferably in the range of 50 to 170 g / m ² . Moreover, it is preferable to carry out baking and drying of the organic coating at 80 to 120 ° C. for 1 to 3 minutes.

  The inorganic layer 16 is formed from an inorganic paint (hereinafter referred to as an inorganic paint). Any appropriate inorganic paint can be used. Specifically, as an inorganic coating material, for example, a silicon alkoxide coating material prepared by adding a condensation reaction catalyst such as polyorganosiloxane or alkyl titanate to a silica dispersion oligomer solution of organosilane, or further adding silica. Can be used.

The inorganic layer 16 is formed, for example, by applying an inorganic paint on the surface of the organic layer 15 and baking and drying. The method for applying the inorganic paint is selected from the group consisting of a spray gun, a roll coater, a flow coater, and a curtain coater, for example. The coating amount after drying of the inorganic paint is preferably within the range of 4 to 25 g / m ² . Baking and drying of the inorganic coating material is preferably performed, for example, in a range of 80 to 160 ° C. for 60 seconds or more using a jet dryer.

  The colored coating film 13 is formed from a colored coating film paint. The colored coating film contains an organic pigment and a photocatalytic material. In particular, the colored coating film paint is preferably an acrylic resin-based enamel paint containing an organic pigment and a photocatalytic material. Specifically, for example, an enamel prepared by adding an organic pigment, an organic solvent, an antifoaming agent, an additive such as a thickener, water, and the like to an acrylic emulsion resin or an acrylic silicone emulsion resin and stirring and dispersing it. It can be used as a paint.

  Examples of the organic pigments include rhodamine lake, methyl violet lake, quinoline yellow lake, malachite green lake, alizarin lake, carmine 6B, lakelet C, disazo yellow, lakelet 4R, chromophthal yellow 3G, chromophthal scarlet RN, nickel azo yellow, permanent. From the group consisting of Orange HL, Phthalocyanine Blue, Phthalocyanine Green, Flavanthrone Yellow, Thioindigo Bordeaux, Perinone Red, Dioxadone Violet, Quinacridone Red, Naphthol Yellow S, Pigrant Green B, Lumogen Yellow, Signal Red, Alkaline Blue, Aniline Black One or more selected materials may be included.

  The photocatalytic material can contain, for example, one or more materials selected from the group consisting of titanium oxide, zinc oxide, cadmium sulfide, and tungsten oxide.

  It is preferable that content of the photocatalyst material which the colored coating film 13 contains exists in the range of 5-10 mass%. When the content of the photocatalytic material is 5% by mass or more, a change in color can be promoted. When content of a photocatalyst material is 10 mass% or less, peeling of the colored coating film 13 can be suppressed for a long period of time.

  Moreover, the colored coating film paint may contain not only an organic pigment but also an inorganic pigment. The inorganic pigment can contain, for example, one or more materials selected from the group consisting of calcium carbonate, titanium oxide (titanium white), bitumen, ultramarine, iron oxide, aluminum paste, bronze powder, and carbon black.

The colored coating film 13 is formed, for example, by applying a colored coating film coating on the surface of the inorganic layer 16 and then baking and drying. The method for applying the colored coating film paint is selected from the group consisting of a spray gun, a roll coater, a flow coater, and a curtain coater, for example. The coating amount of the colored coating paint is preferably in the range of 40~170g / ^{m 2.} The applied colored coating film is preferably performed at 80 to 120 ° C. for 1 to 3 minutes using, for example, a jet dryer.

  In the present embodiment, the colored coating film 13 is formed on the surface of the inorganic layer 16 and covers the entire inorganic layer 16. For this reason, since the colored coating film 13 is not in direct contact with the organic layer 15, it is possible to prevent deterioration of the organic layer 15 and peeling of the colored coating film 13 due to photocatalytic action.

  The inorganic clear layer 17 is formed from an inorganic clear coating (hereinafter referred to as an inorganic clear coating). An appropriate inorganic clear coating can be used. Specifically, for example, as an inorganic clear coating, a silicon alkoxide system prepared by adding a condensation reaction catalyst such as polyorganosiloxane or alkyl titanate to a silica-dispersed oligomer solution of organosilane, or further adding silica. A paint can be used.

  When the inorganic paint used for forming the inorganic layer 16 is a clear paint, this inorganic paint may be used as the inorganic clear paint.

The inorganic clear layer 17 is formed, for example, by applying an inorganic clear coating on the surface of the colored coating film 13 and baking and drying. The method for applying the inorganic clear paint is selected from, for example, a spray gun, a roll coater, a flow coater, a curtain coater, and the like. At this time, the coating amount of the inorganic clear coating after drying is preferably in the range of 4 to 25 g / m ² . Baking and drying of the applied inorganic coating is preferably performed, for example, within a range of 80 to 160 ° C. for 60 seconds or more using a jet dryer.

  By forming the inorganic clear layer 17 on the colored coating film 13, the weather resistance of the decorative building board 1 can be improved.

  In the decorative building board 1 formed as described above, since the colored coating film 13 contains a photocatalytic material and an organic pigment, the organic pigment is oxidized by the photocatalytic material when the colored coating film 13 is irradiated with ultraviolet rays. . When the organic pigment is oxidized, the colored coating film 13 is discolored and the design of the decorative building board 1 by the colored coating film 13 is changed.

  This embodiment can provide the decorative building board 1 in which a design changes with progress of time by positively utilizing the discoloration of the colored coating film 13 by a photocatalytic action.

  Hereinafter, tests conducted for verifying the effects of the present invention will be described.

(Test 1)
As shown in FIG. 1, the decorative building board in Test 1 (referred to as a decorative building board A) is formed by sequentially laminating a sealer coating 11 a, a colored layer 12, a colored coating 13, and an organic clear layer 14 on a substrate 11. Manufactured by.

  Here, as the base material 11, a cement substrate was used, which was applied with sealer coating.

  The colored layer 12 was formed from an acrylic resin paint containing an organic pigment based on an acrylic emulsion (AcEm). In this paint, 100 parts by weight of the acrylic emulsion resin is added with 33 parts by weight of an organic pigment (made of phthalocyanine green), 13 parts by weight of an additive (made of a thickener and a matting agent), and 26 parts by weight of water, followed by mixing and stirring. Prepared.

  Then, this paint was spray-coated, and a heating layer was formed under conditions of 110 ° C. for 60 seconds to form a colored layer 12 having a thickness of 50 μm.

The colored coating film 13 was obtained by adding 5 parts by weight of a TiO ₂ solution as a photocatalyst material to the acrylic resin paint used for the colored layer 12. Then, this paint was applied by brushing to a very small area of the colored layer 12 so as not to stand out in appearance. This was heated and formed under conditions of 110 ° C. for 60 seconds or more to form a colored coating film 13 having a thickness of 25 μm.

  Further, an organic clear layer 14 was formed by applying a clear paint based on an acrylic emulsion to the colored layer 12 and the colored coating film 13 and heating to form a film.

  The decorative building board A was produced as described above.

  Subsequently, an air exposure test was performed using the decorative building board A. A color difference meter “CR-400” manufactured by Konica Minolta Holdings, Inc. was used to measure the color values of the colored coating film and the colored layer of the decorative building board A.

In the atmospheric exposure test, a decorative building board was installed at an inclination of 20 ° on the south surface, and an exposure test was conducted for 4 years. In the test, first, the L ^* value of the colored coating film and the colored layer of the decorative building board A was measured, and this was used as the reference value L ^* ₀ . And the color difference (DELTA ⁾ L ^* was computed by measuring L ^* value of the colored coating film and colored layer of the decorative building board A every year, and subtracting L ^* ₀ .

  The results are shown in Table 1 and FIG.

From Table 1 and FIG. 3, the value of ΔL ^* of the colored coating film of the decorative building board A is much larger than that of the colored layer. That is, it can be understood that the colored coating film of the decorative building board A is very easily changed in color as compared with the colored layer of the decorative building board B.

  From this, the repainting time of the organic clear layer can be determined by measuring the color value of the colored coating film in the decorative building board of the present invention.

(Test 2)
As shown in FIG. 2, the decorative building board in Test 2 (referred to as a decorative building board C) has a sealer coating film 11 a, an organic layer 15, an inorganic layer 16, a colored coating film 13, and an inorganic clear layer on a substrate 11. 17 was manufactured by sequentially laminating.

  Here, as the base material 11, a cement substrate was used, which was applied with sealer coating.

  Subsequently, an acrylic resin paint based on an acrylic emulsion (AcEm), which is an organic substance, was applied to the substrate 11 and heated to form an organic layer 15.

  Then, an inorganic coating was applied to the organic layer 15 to form an inorganic layer 16. The inorganic paint was formed as follows.

  First, in a flask equipped with a stirrer, a heating jacket, a condenser and a thermometer, methanol-dispersed colloidal silica sol (“MA-ST” manufactured by Nissan Chemical Industries, Ltd .; particle diameter 10-20 mμ, solid content 30%) 100 parts by weight, methyltri 68 parts by weight of methoxysilane and 10.8 parts by weight of water were charged, and a partial hydrolysis reaction was carried out at a temperature of 65 ° C. for about 5 hours with stirring, followed by cooling to prepare an A component having a solid content of 36%.

  Also, weigh a mixed solution of 220 parts by weight of methyltriisopropoxysilane and 150 parts by weight of toluene into a flask equipped with a stirrer, a heating jacket, a condenser, a dropping funnel and a thermometer, and mix 108 parts of 1% aqueous hydrochloric acid with the above. Methyl triisopropoxysilane was hydrolyzed by adding dropwise to the solution in 20 minutes. Stirring was stopped 40 minutes after the dropping, the lower layer water / isopropyl alcohol mixed solution containing a small amount of hydrochloric acid separated into two layers was separated, and the remaining toluene resin solution hydrochloric acid was removed by washing with water. Toluene was removed under reduced pressure, and then diluted with isopropyl alcohol to prepare a B component which was a 40% isopropyl alcohol solution of silanol group-containing organopolysiloxane having an average molecular weight of about 2000.

  Further, N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane was used as the C component.

  Then, 70 parts by weight of the component A, 30 parts by weight of the component B and 1 part by weight of the component C are mixed and stirred, spray-coated, and cured at 120 ° C. for 30 minutes to form an inorganic layer 16 having a thickness of 10 μm. did.

  The colored coating film 13 was formed from an acrylic resin paint based on an acrylic emulsion (AcEm). This paint contains an organic pigment and a photocatalytic material.

  This paint is composed of 33 parts by weight of an organic pigment (made of phthalocyanine green), 5 parts by weight of a photocatalytic material (titanium oxide), and 13 parts by weight of an additive (made of a thickener and a matting agent) with respect to 100 parts by weight of the acrylic emulsion resin. The mixture was prepared by adding 26 parts by weight of water and mixing and stirring.

  Then, this paint was applied by spraying, and heated to form a film at 110 ° C. for 60 seconds to form a colored coating film 13 having a thickness of 25 μm.

  The inorganic clear layer 17 was formed by applying the same paint as that used for the inorganic layer 16 to the colored coating film 13 and then heating to form a film.

  A comparative decorative building board (referred to as a decorative building board D) was also produced. The decorative building board D was produced by sequentially laminating a sealer coating 11a, an organic layer 15, an inorganic layer 16, a colored coating 13 and an inorganic clear layer 17 on a base material 11.

  In producing this decorative building board D, the colored coating film 13 was formed without adding a photocatalytic material to the paint. Otherwise, the decorative building board D was produced in the same manner as the decorative building board C.

  And about the decorative building board C and the decorative building board D, the atmospheric exposure test was done.

In the air exposure test, the decorative building boards C and D were installed with an inclination of 20 ° on the south surface, and the exposure test was conducted for 2 years. In the test, the color difference ΔE ^* of the colored coating film was measured every six months using a color difference meter “CR-400” manufactured by Konica Minolta Holdings. Here, ΔE ^* is Δ defined by the following equation.
ΔE ^* = [(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² ] ^1/2
ΔL ^* , Δa ^* , Δb ^* are defined by the following equations.
ΔL ^* = L ^* _1- L ^* ₀
Δa ^* = a ^* ₁₋ a ^* ₀
Δb ^* = b ^* _1- b ^* ₀
L ^* ₀ , a ^* ₀ , and b ^* ₀ in the above formula are measured values of L ^* of the colored coating film at the start of the exposure test. L ^* ₁ , a ^* ₁ , and b ^* ₁ in the above formula are the L ^* value, a ^* value, and b ^* value of the colored coating film during the exposure test. Here, L ^* , a ^* , and b ^* are the L ^* value, a ^* value, and b ^* value of the L ^* a ^* b ^* color system defined in JIS Z 8729.

  The results of Test 2 are shown in Table 2 and FIG.

From Table 2 and FIG. 4, the colored coating film of the decorative building board C exposed for two years has a ΔE ^* of 4.9 larger than the colored coating film of the decorative building board D. That is, it can be seen that the color coating of the decorative building board C is more likely to change in color than the colored coating of the decorative building board D. That is, by forming the colored coating film containing the photocatalytic material on the entire surface like the decorative building board C, the color of the decorative building board is changed earlier than usual, so the user changes the color at an early stage. You can enjoy the change of the exterior design with the decorative building board.

DESCRIPTION OF SYMBOLS 1 Cosmetic building board 11 Base material 12 Colored layer 13 Colored coating film 14 Organic clear layer 15 Organic layer 16 Inorganic layer

Claims (2)

A decorative building board obtained by painting a base material,
A colored coating film containing an organic pigment and a photocatalytic material is provided .
On the base material, a colored layer, the colored coating film, and an organic clear layer are sequentially laminated,
The decorative building board, wherein the colored coating film covers a part of the colored layer . A method for determining a repainting time of the organic clear layer in the decorative building board according to claim 1,
Set the allowable range of color values for the colored coating,
Measure the color value of the colored coating film,
When the color value of the colored coating film is within the allowable range, it is determined that repainting of the organic clear layer is unnecessary,
A method for determining the repainting time of the organic clear layer, wherein it is determined that the repainting of the organic clear layer is necessary when the color value of the colored coating film is outside the allowable range.

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