JP2003260410A - Method for producing decorative panel for construction - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a decorative panel for construction for which the types of coating materials and coating conditions can be easily changed and by which coating can be economically carried out at a high coating efficiency. <P>SOLUTION: An undercoating material is applied to the surface of a construction substrate 2 for forming an undercoating main material layer 41 and a hiding coating is applied to the layer 41 for forming a hiding layer 42, so that an undercoating layer 4 comprising the undercoating main material layer 41 and the hiding layer 42 can be formed. Further, a coloring coating is applied to the undercoating layer 4 to form a top coat layer 5. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a decorative board for construction such as interior material for construction and exterior material for construction. In particular,
Like brick, tile, masonry, multi-layer patterns, etc.
It is suitable for a method for producing a decorative board for construction used as an exterior material for construction having various relief patterns such as grooves and irregularities colored in various colors on the surface.

[0002]

2. Description of the Related Art Conventionally, there have been known many architectural decorative materials having various relief patterns such as grooves and irregularities colored in various colors on the surface thereof in order to improve the appearance of a building and a manufacturing method thereof. For example, Japanese Unexamined Patent Publication No. 7-89006 describes a method for producing a decorative board for construction that expresses the appearance of a stone surface such as natural stone by applying a paint mixed with granular aggregate on the surface by a spray coating method. ing.

Further, in the direction of JP-A-7-166110,
Architectural paint in which synthetic resin vehicle is mixed with round-cornered aggregate such as artificial sand, natural sand, crushed ceramics, crushed glass, and plastic beads, and construction in which this architectural paint is applied to the surface of the building substrate Cosmetic materials for use are described. In this publication, air spray coating, airless spray coating, flow coater coating and the like are shown as methods for applying the coating material.

Further, Japanese Patent Laid-Open No. 8-151541 discloses that
An architectural coating in which colored dispersed particles and flaky pigments are dispersed in a dispersion medium is described. In this publication, spray coating methods, roller coating methods, brush coating coating methods, iron coating coating methods and the like are shown as methods for applying the coating material.

Further, in Japanese Patent Laid-Open No. 7-62828, a construction decorative board having a convex portion of a building substrate having an uneven surface coated in two or more kinds of color tone, and two or more kinds of color tone on the convex portion. Describes a method for manufacturing a decorative board for construction, in which the coating composition is applied by an inkjet printer type coating machine.

[0006] As described above, as a coating method used in the method for manufacturing a decorative material for construction, a coating method in which a person directly applies a coating such as a brush coating method or a trowel coating method, or a coating method is sprayed from a nozzle. Spray painting methods such as air spray painting method and airless spray painting method
Flow coater coating method to apply paint by overflowing the container, roller coater coating method to apply paint to a roller and paint with this roller, inkjet printer method used for printers that print ink by spraying ink on paper etc. The coating method using an ink jet printer type coating machine, which has substantially the same structure as that of the printing machine, is often used.

[0007]

However, in the painting method in which a person directly applies the paint, since the person paints the decorative veneer for construction one by one, a skilled craftsman and an extremely large number of painting steps are required. It is not suitable for manufacturing industrial veneer for manufacturing. In the spray coating method, since the sprayed paint becomes a mist and scatters, the coating efficiency of the paint to the building substrate to be coated is about 40%, and the paint loss is large. In particular, since the top coating material is expensive, it is not suitable for the method of applying this top coating material.

Although the flow coater coating method and the roller coater coating method increase the coating efficiency on the building substrate,
It is not suitable for a method for manufacturing a decorative decorative board having a relief pattern. That is, when applying the coating material to the building substrate having a groove or an uneven pattern on the surface, in the flow coater coating method,
Since the paint applied to the convex part flows to the concave part, there is a difference in the coating amount between the concave part and the convex part, and it is difficult to apply it uniformly.In the case of the roller coater coating method, the paint contacts the roller. It is difficult to apply the coating material only to the convex portion and to the concave portion.

Further, as described above, since there is a difference in the coating amount of the paint, the building substrate is visible and ugly in a place where the coating amount is small. Therefore, in order to cover the surface of the building substrate so that it cannot be seen, it is necessary to apply an excessive amount of paint, which causes a problem of large loss of paint. Furthermore, when changing the type of paint or changing the coating conditions such as the coating amount, it takes time to replace the existing paint in the coating machine with new paint or to completely change to the new coating conditions. . Therefore, there is a problem that the time and the loss of the paint during this period are large.

The method of coating with an ink jet printer type coating machine is such that the paint can be applied to the required places as many times as necessary, and the surface having grooves or irregularities can be overpainted, or overpainted in a plurality of color tones. It is a very preferable method for painting. However, as can be said for all of the above-mentioned coating methods, when applying a colored paint to a building board, generally, an undercoat paint is applied to the surface of the building board to provide an undercoat layer, and Although the coloring paint is applied to provide the top coating layer, the top coating layer needs to be thick in order to completely hide the surface of the building substrate. Moreover, the colored paint used for this topcoat layer is expensive. Therefore, there is a demand to reduce the amount of this expensive colored paint as much as possible.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, to provide a method for manufacturing a decorative board for construction, in which the type of paint and the coating conditions can be easily changed, the painting efficiency is good, and the painting can be done at low cost. That is.

[0012]

The present invention has been made to achieve the above object, and the invention according to claim 1 is to apply an undercoat paint to the surface of a building substrate to form an undercoat main material layer. And, as a hiding layer by applying a hiding paint on this,
An undercoat coating layer consisting of this undercoat main material layer and a masking layer is provided, and a coloring paint is applied onto this undercoat coating layer to provide an overcoat coating layer.

A second aspect of the present invention is the method according to the first aspect, wherein the method of providing the top coating layer is a method of applying a colored coating material by an ink jet printer type coating machine.

A third aspect of the present invention relates to the first aspect of the present invention, wherein the concealing paint comprises a pigment which is substantially the same as the pigment contained in the undercoat paint and the colored paint.

A fourth aspect of the present invention relates to the first aspect of the present invention, wherein the method of providing the undercoat coating layer comprises an undercoat paint passage and a pigment injection passage opened at the tip of the undercoat paint passage. Using a coating machine equipped with a head consisting of an undercoat paint passage and a mixing section provided at the tip of the pigment injection path, apply the undercoat paint that has passed through the undercoat paint passage and the mixing section to the surface of the building substrate. As the undercoat main material layer, and then the undercoat paint that has passed through the undercoat paint passage,
This is a method in which the pigment that has passed through the pigment injection path is mixed almost uniformly in the mixing section to form a hiding paint, and this hiding paint is applied to form a hiding layer.

The invention according to claim 5 relates to the invention according to claim 1, wherein the undercoat main material layer is 70 to 90% of the thickness of the undercoat coating layer, and the hiding layer is of the thickness of the undercoat coating layer. It is 30 to 10%.

The building substrate used in the present invention may be any suitable one such as flexible board, calcium silicate board,
Gypsum slag perlite board, hard wood chip cement board, precast concrete board, ALC board, gypsum board, and other inorganic boards commonly used for construction boards, and inorganic and aluminum boards, steel sheets, stainless steel sheets, and other metal sheets. A composite plate with a hard Birni chloride plate or a plastic plate such as an acrylic plate is preferable.

These inorganic plates and composite plates may be plate-shaped members having a smooth surface, but they can be molded by a molding die having an inner surface with a concave-convex cormorant, or by means such as embossing or pressing. A plate-like body having a surface on which grooves or uneven patterns are formed on the surface, by combining the grooves or uneven patterns on the surface and a color colored in various colors by applying a coloring paint,
This is preferable because it is possible to express a considerably high degree of design. Further, a hard wood chip cement plate in which wood chips are mixed with cement has characteristics of wood and cement and is excellent in processability, and therefore, it is preferable in some cases.

Further, an undercoat paint is applied to the surface of this building substrate to form an undercoat main material layer, but the adhesion of the undercoat paint is poor as in the case of a wood board such as a flexible board or a hard wood chip cement board. There are cases. In such a case, it is advisable to coat the surface of this building substrate with a sealer and provide a sealer layer on the surface of the building substrate to improve the adhesion of the undercoat paint.

The undercoat paint used in the present invention is mainly composed of a binder, a solvent, and optionally a pigment. As a binder, acrylic resin type,
Examples thereof include an acrylic urethane resin type, an epoxy resin type, an acrylic epoxy resin type, a chlorinated polypropylene resin type, an alkali silicate type and an alkyl silicate type. As the solvent, a commonly used organic solvent type or aqueous type can be used. This solvent has a specific evaporation rate of 5 by a gravimetric method using 100% pure butyl acetate.
Those in the range of 0 to 380 are preferable. 80 is more preferable
~ 200.

Specifically, an aromatic hydrocarbon solvent such as toluene and xylene; an alcohol solvent such as ethyl alcohol, isopropyl alcohol and isobutyl alcohol; positive propyl acetate, normal butyl acetate, butyl acetate;
Typical examples thereof include ester solvents such as isobutyl acetate; aliphatic hydrocarbon solvents such as petroleum benzine and rubber volatile oil. It is also possible to use a solvent having a specific evaporation rate other than the above range in a range of 20% or less with respect to all the solvents mainly containing the above solvent.

A pigment may be added to the undercoat paint, and examples of the pigment include titanium oxide, iron oxide,
Various oxides such as complex oxides (nickel titanium type, chromium titanium type, bismuth vanadium type), carbon black, yellow lead, quinacridone, diketoprolopyrrole,
Representative examples thereof include various organic pigments such as benzimidazolone, isoindolinone, anthrapyramidine, phthalocyanine, frene and dioxazine.

In the present invention, a masking paint is applied on the undercoating main material layer to form a masking layer. The hiding paint used at this time contains a binder, a solvent and a pigment as main components, but preferably has a great hiding property. As the binder, pigment and solvent used in this concealing paint, those described in the undercoat paint can be used.

As such a hiding paint, as described in claim 3, when a hiding paint composed of a pigment which is substantially the same as the pigment contained in the after-mentioned overcoating layer is used as the undercoating paint, the undercoating agent coated with the undercoating paint is used. Adhesion to the material layer is good, it becomes difficult to distinguish the overcoat layer and the hiding layer, and the surface of the building substrate can be hidden with the almost same pigment contained in the hiding layer and the overcoat layer. It is preferable because the top coat layer can be thinned only by hiding the surface with the hiding layer.

As a method of applying the undercoat paint and the masking paint, a known coating method such as a spray coating method such as an air spray coating method and an airless spray coating method, a flow coater coating method, and a roller coating method can be adopted. However, when coating is performed by a coating method using a coating machine having a head, such as a spray coating machine or an inkjet printer type coating machine, the head of the coating machine is set as in the invention of claim 4. If a head having an undercoat passage, a pigment injection passage, and a mixing portion is used, the undercoat paint and the masking paint can be coated with the same coating machine, and it is possible to easily switch from the undercoating paint to the masking paint. It is preferable because the loss of the undercoat paint and the masking paint is reduced when changing to the undercoat paint and the masking paint.

Further, the undercoat coating layer is composed of the undercoat main material layer and the concealing layer. The composition ratio at this time is such that the undercoat main material layer is 7 times the thickness of the undercoat coating layer as in the invention of claim 5.
0 to 90%, and the hiding layer is 10 times the thickness of the undercoat coating layer.
-30% is preferable. The reason is that the undercoat main material layer is 90
%, The hiding power will be reduced and the coating layer will be 30%.
This is because if the above is the case, the cost will increase.

In the present invention, an overcoat coating layer is provided on this undercoat coating layer. The coloring paint used for this top coating layer contains a binder, a pigment, and a solvent as main components, and further contains, if necessary, an extender pigment, a dye, an electric conductivity adjusting agent, a surfactant, a water retention agent, etc. Composed. As the binder, pigment and solvent used in this colored paint, those described for the undercoat paint can be used. In this case, the preferable ratio of each component is that the binder is 1
~ 50 wt%, 0.1-20 wt% pigment, 49 solvent
~ 99% by weight.

The coloring paint may be applied by a known coating method such as a spray coating method such as an air spray coating method or an airless spray coating method, a flow coater coating method or a roll coater coating method. According to the invention as set forth in claim 2, the method of coating with an ink jet printer type coating machine can coat various kinds of paint in a necessary place in a necessary thickness, and also when changing colors or changing coating conditions. Is preferable because the loss of

The colored paint used when coating with the ink jet printer type coating machine has a pore size of about 1/10 of the diameter of the nozzle of the ink jet printer type coating machine after mixing and stirring the respective components. It is preferable to use after filtering with a filter as described below and refining because the nozzle is less likely to be clogged when the colored paint passes through.

The viscosity of the colored coating material in this case is preferably 4 to 15 cP (20 ° C.) (4 to 15 mPa · s (2
0 ° C.)), more preferably 5 to 12 cP (20 ° C.) (5
˜12 mPa · s (20 ° C.)). The reason is that the paint discharged from the nozzle is likely to become a normal paint droplet. Another property of the paint is that the surface tension is 2
0-60 dyn / cm (200-600 μN / cm),
The specific resistance is 200 to 3000 Ω · cm and the specific gravity is 0.8 to
3 is preferable.

The method of coating with this ink jet printer type coating machine may be performed with a conventional ink jet printer type coating machine as described in JP-A-7-62828. Further, various control methods for controlling the coating material in this inkjet printer type coating machine can be adopted. Typical examples of such control method include an on-demand method, a charge control method, and a method of ejecting ink by a thermal head.

Next, a method of coating with an ink jet printer type coating machine controlled by an on-demand system by opening / closing a solenoid valve will be described in detail with reference to FIGS. 10 and 11. FIG. 10 is a front view of a state in which paint is applied by an inkjet printer type coating machine, and FIG. 11 is a side view of FIG.

In FIGS. 10 and 11, reference numeral 100 is a plate to be coated. Reference numeral 200 denotes a conveyor on which the plate 100 is placed, and a printer head 300 of an inkjet printer is arranged above the conveyor 200. This printer head 300 has a conveyor 200
A plurality of nozzles 301 each having a diameter of 0.1 to 0.4 mm are arranged in parallel in a downward direction at a pitch of 1 to 5 mm over the entire width direction.

At this time, the printer head 300 may be arranged so as to correspond to the width direction of the conveyor 200 by itself, or the printer head 300 may be arranged in accordance with the size of the plate body 100 (that is, the width of the conveyor 200). A plurality of heads 300 may be arranged side by side in the traveling direction. A paint tank 400 is connected to the printer head 300, and the paint tank 4
The paint 401 stored in 00 can be sent to the printer head 300 by the pump 500 and the relief valve 501.

Reference numeral 302 is a valve for individually opening and closing a plurality of nozzles 301 provided below the printer head 300. The opening and closing of the valve 302 can be individually controlled by the valve control device 600. Reference numeral 700 denotes a pattern data storage unit in which a pattern to be printed and a pattern pattern corresponding to the pattern are recorded.
Reference numeral 01 is a control unit (computer) that issues a control signal to the valve control device 600 based on the pattern data input from the storage unit 700.

Reference numeral 800 denotes a photoelectric tube type sensor in which a light projector 801 and a light receiver 802 are provided on both sides of a substrate transfer path on the conveyor 200. The photoelectric tube type sensor 800 is
The plate body 100 passing on the conveyor 200 can be detected. Then, the detection signal detected by the photo-electric tube type sensor 800 is transmitted to the control unit 701.

Reference numeral 205 is a drive roll 2 of the conveyor 200.
An encoder connected to 06, for example, 200
A pulse is transmitted to the control unit 701 at every minimum rotation angle of 360 degrees of 0/0. In the above description, the printer head 300 is fixed, but a method in which the printer head 300 is controlled and operated in the width direction or the traveling direction of the architectural substrate 100 provided with the undercoat coating layer may be used.

Next, a method of applying the top coat with this ink jet printer type coating machine will be described. First, the pump 6 is operated to turn on the paint 40 in the paint tank 400.
1 is sent to the printer head 300, and the paint 401 is sprayed from the nozzle 301 whenever the valve 302 is opened.

Next, the plate 100 is placed on the conveyor 200 and passed under the printer head 300. Then, the photoelectric tube type sensor 800 detects the plate body 100 passing under the coating machine, and the control unit 70 outputs this detection signal.
Send to 1. The control unit 701 informs the storage unit 700 of the signal from the photoelectric tube type sensor 800, and the pattern data recorded in the storage unit 700 is controlled by the control unit 70.
Send to 1.

Then, the control unit 701 causes the storage unit 70 to
According to the pattern data recorded in 0, the valve 30
It issues a command to the valve controller 600 to open and close 2. In the valve control device 600, this control unit 701
The valve 302 is opened / closed in accordance with the command. Valve 30
When 2 opens, the paint 401 is sprayed from the nozzle 301,
A pattern corresponding to the pattern data is applied on the plate 100.

At this time, since the conveyor 200 is moved accurately by the encoder 205, the paint 401 can be applied on the plate 100 at a predetermined location and a predetermined thickness. A plurality of the paint tanks 400 and the printer head 300 are provided, and the plurality of paint tanks 400
Different kinds of paints are put in the respective paint tanks, and different paints are sent from the paint tanks 400 to the printer heads 300, and the paints are separately sprayed onto the plate body 100 from the printer heads 300 for coating. By doing so, it is possible to apply a plurality of paints.

As described above, when the coating machine of the ink jet printer type is used, various kinds of coating materials can be coated at a predetermined position with a predetermined thickness, so that even if there are grooves or irregularities on the surface, good coating can be performed.

In the present invention, as described above, the undercoat coating layer and the topcoat coating layer are provided, but a clear layer may be provided on the topcoat coating layer. Providing this clear layer is preferable because it increases the gloss. To provide this clear layer, a clear paint may be applied on the top coat layer.

As the clear paint used at this time,
Acrylic copolymers with hydrolyzable silyl groups in the side chains and fluorine-containing copolymers with hydrolyzable silyl groups in the side chains, and transparent or translucent synthesis by adding siloxane compounds etc. to the above copolymers A paint containing a resin and a solvent as main components is preferable. Further, in this clear paint, extender pigments containing a matting agent, coloring pigments, color mica, urethane-based or acrylic-colored beads, urethane-based or acrylic-based transparent or translucent transparent coatings Plastic beads,
Various pigments such as flake graphite, flake iron oxide, plated glass flake, plated mica, pearl pigment, and aluminum flake may be blended.

If desired, a curing catalyst may be added to the clear paint. As such a curing catalyst, inorganic acids such as hydrochloric acid and sulfuric acid, organic acids such as acetic acid and toluenesulfonic acid, and organic bases such as aminos and amines,
Organic metal salts such as carboxylic acid salts of tin, aluminum, boron and silicon, alkyl metal carboxylate salts, alkyl metal oxides, metal acid alkyl esters, metal alkoxides and the like can be used.

Further, it is preferable to mix an aggregate in the clear coating, because an appropriate gloss is obtained and the weather resistance is improved. The clear paint containing this aggregate is
Although the clear paint may be mixed with an aggregate, it is preferable to mix the aggregate with a transparent or translucent synthetic resin paint.

Examples of the transparent or translucent synthetic resin coating used for the clear coating containing the aggregate include acrylic resin, vinyl acetate resin, styrene resin, vinyl chloride resin, vinylidene chloride resin, alkyd resin, urethane resin, A paint prepared by dissolving a transparent or translucent synthetic resin, which is generally used as a paint, such as an epoxy resin, a melamine resin, or a urea resin, in an organic solvent or forming an emulsion is preferable.

The aggregate to be incorporated in the transparent or semi-transparent synthetic resin paint preferably has an average particle size of 30 to 100 μm. The reason is that when it is less than 30 μm, it lacks in brightness and gives a heavy impression.
If it exceeds, a large amount of compounding is required to achieve the purpose of lowering the gloss, and the performance of the coating film itself may be deteriorated. The particle size of the aggregate has a distribution, but this is not a limitation.

As the type of aggregate, it is possible to use sand, plastic beads, crushed glass or flake, granular or scale-like particles such as mica flakes. The color of the aggregate is not particularly limited, but a color different from the hiding paint,
Alternatively, those colored in different colors are preferable because the appearance is improved. In particular, a mixture of aggregates of a plurality of colors is preferable because it is conspicuous and beautiful and the effect is large.

The amount of the aggregate used is preferably 0.5 to 5 parts by weight with respect to 100 parts by weight of the transparent or translucent synthetic resin paint. The reason for this is that if it is less than 0.5 parts by weight, it shines brightly, so it is not possible to obtain the initial effect of the clear layer of lowering the gloss and obtaining an appropriate gloss,
Also, if it exceeds 5 parts by weight, the coating film performance may be deteriorated.

Further, coloring agents such as pigments and dyes, some extender pigments, plasticizers, antioxidants, ultraviolet absorbers, leveling agents, thickeners, and other additives are added to the extent that transparency or translucency is not impaired. You may mix the agent. As a method for applying this clear paint, there are known coating methods such as an air spray coating method, an airless spray coating method, a flow coater coating method, a roll coating method and a method of coating with an inkjet printer type coating machine which are usually performed. Can be adopted. The coating amount is preferably about 80 to 150 g / m ² .

(Operation) In the invention of claim 1, an undercoat paint is applied to the surface of the building substrate to form an undercoat main material layer,
As a concealment layer by applying a concealing paint on this, a base coat layer consisting of this base coat main material layer and a cover layer is provided, and a color coat is applied on the base coat layer to provide a top coat layer, Due to the concealment layer coated with the concealing paint and the overcoat coating layer coated with the coloring paint, the surface of the building board becomes difficult to see from the top of the building decorative board, and a beautiful building decorative board is obtained.

Further, since the surface of the decorative veneer for construction is hardly visible due to the concealing layer, the thickness of the expensive top coating layer can be made thinner than before, and the decorative veneer for construction can be manufactured at low cost.

According to the second aspect of the present invention, the method of forming the overcoat coating layer is a method of applying the colored coating material with an ink jet printer type coating machine. The necessary paint can be applied to the part to the required thickness. As a result, extra colored paint is not applied or colored paint is not applied to unnecessary places, the desired painting can be done with a small amount of colored paint, and when changing colors or changing coating conditions, The loss of time and the loss of paint can be minimized.

According to the third aspect of the present invention, since the hiding paint is composed of the undercoating paint and a pigment which is substantially the same as the pigment contained in the coloring paint, the hiding paint and the undercoating paint have good adhesion, and the topcoating is performed. It becomes difficult to distinguish it from the colored paint in the paint layer, and the covert paint and the approximately the same pigment contained in the topcoat paint layer can make the surface of the building board difficult to see efficiently from the surface of the decorative decorative board for construction. .

According to a fourth aspect of the present invention, the method of providing the undercoat coating layer is such that the undercoat paint passage, the pigment injection passage opened at the tip of the undercoat paint passage, the undercoat paint passage and the tip of the pigment injection passage. Using a coating machine equipped with a head consisting of a mixing section provided in, on the surface of the building substrate, the undercoat paint passage and the undercoat paint that has passed through the mixing section is applied as the undercoat main material layer, and then, The undercoating paint that has passed through the undercoating paint passage and the pigment that has passed through the pigment injection passage are mixed almost uniformly in the mixing section to form a hiding paint, and this hiding paint is applied to form a hiding layer. An undercoating main material layer and a masking layer can be provided by a machine, the undercoating paint can be smoothly switched to the masking paint, and the loss of the undercoating paint and the masking paint can be reduced.

In the invention of claim 5, the undercoat main material layer is 70 to 90% of the thickness of the undercoat coating layer, and the concealing layer is 30 to 10% of the thickness of the undercoat coating layer. In addition, sufficient concealing property can be obtained, the top coating layer can be thinned, and the decorative board for construction can be manufactured at low cost.

[0058]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described with reference to examples. (Embodiment 1) FIGS. 1 and 2 show an embodiment of the present invention. FIG. 1 (a) is a perspective view showing a decorative board for construction, and (b).
2A is a sectional view taken along the line AA in FIG. 2A, and FIG. 2 is a sectional view showing the head of an air spray type coating machine used when the undercoat coating layer is provided.

In FIG. 1 and FIG. 2, reference numeral 1 denotes a decorative veneer for a building. As shown in FIG. 1, the decorative veneer for a building 1 is a hard wood chip cement plate having a grid-like concavo-convex pattern on its surface. Substrate 2, sealer layer 3 provided on the surface of building substrate 2, undercoat coating layer 4 provided on this sealer layer 3, and topcoat coating layer provided on this undercoat coating layer 4. 5 and a clear layer 6. The undercoat coating layer 4 is composed of an undercoat main material layer 41 and a masking layer 42.

Reference numeral 7 denotes a head of an air spray type coating machine used for providing an undercoat coating layer. The head 7 has an undercoat paint passage 71 and a tip of the undercoat paint passage 71, as shown in FIG. It is composed of a pigment injection passage 72 that is open to the portion, the undercoat paint passage 71, and a mixing portion 73 provided at the tip of the pigment injection passage 72.

Next, a method of manufacturing the decorative board 1 for construction will be described. An ethylene vinyl acetate copolymer resin-based sealer is applied to the surface of the building substrate 2 with an air spray coater and dried to form a sealer layer 3 on the entire surface of the building substrate 2. Next, an acrylic resin emulsion base coat is applied on the sealer layer 3 in an amount of about 90 g.
/ M ² to be coated with an air spray coating machine and dried to form an undercoat main material layer 41.

Next, a pigment is added to the acrylic resin emulsion-based undercoat paint on the undercoat main material layer 41,
The hiding paint that was stirred and made uniform was applied in an amount of 20 g / m ²
Then, the hiding layer 42 is provided by coating with an air spray coating machine and drying. In this way, the undercoat coating layer 4 including the undercoat main material layer 41 and the masking layer 42 was provided.

The method of providing the undercoat coating layer 4 in this case will be described in more detail. The head 7 shown in FIG. 2 is attached to the tip of the air spray coating machine, the undercoat paint is passed through the undercoat paint passage 71 and the mixing portion 73, and the undercoat paint is sprayed and applied on the sealer layer 3 and then dried. hand,
The undercoating main material layer 41 is provided, and then the undercoating paint is supplied from the undercoating paint passage 71 and the pigment is supplied from the pigment injection passage 72, respectively, and the mixture is uniformly stirred in the mixing section 73 to form a hiding paint. Is sprayed onto the undercoat main material layer 41, and is then dried to form a concealing layer 42, and the undercoat coating layer 4 including the undercoat main material layer 41 and the concealing layer 42 is provided.

Thus, using this head 7,
The undercoating paint and the masking paint can be applied by the same air spray coating machine to provide the undercoating main material layer 41 and the masking layer 42, and the switching from the undercoating paint to the masking paint can be performed smoothly. Less paint and concealment paint loss.

Next, a colored opaque acrylic resin emulsion-based coloring paint was applied by an ink jet printer type coating machine so that the applied amount was 40 g / m ² .
The top coat layer 5 is provided by drying. The pigment contained in this colored and opaque color paint is substantially the same as the pigment contained in the hiding paint.

Further, a transparent acrylic resin emulsion (solid
Silica sand (average particle size) for 100 parts by weight of 50% by weight
40 μm) 4.0 parts by weight, and uniformly stirred to
Manufacture a clear paint and apply this clear paint with an air spray.
With coating machine, coating amount 140g / m ²So that it becomes warm
Provide a clear layer 5 by drying at a temperature of 80 ° C. for 20 minutes
The architectural decorative material 1 is manufactured.

(Embodiment 2) FIG. 3 shows another embodiment of the present invention and is a sectional view showing a part of a decorative board for construction.

Comparing Example 2 shown in FIG. 3 with Example 1 shown in FIGS. 1 and 2, only the clear layer 6a is different. Therefore, the clear layer 6a will be mainly described. That is, the architectural decorative board 1a according to the second embodiment.
As shown in FIG. 3, the building board 2a is a hard wood chip cement board having an uneven pattern on the surface, and the building board 2a.
A sealer layer 3a provided on the surface of the undercoat layer, an undercoat coating layer 4a provided on the sealer layer 3a, an overcoat coating layer 5a provided on the undercoat coating layer 4a, and a clear layer 6a. .

The undercoat coating layer 4a comprises an undercoat main material layer 41a and a masking layer 42a. Also, the clear layer 6a
Is a layer formed by applying a clear coating consisting of 100 parts by weight of a transparent acrylic resin emulsion (solid content 50% by weight) and 2.0 parts by weight of spherical acrylic resin beads (average particle size 70 μm).

Next, a method of manufacturing the decorative decorative board 1a will be described. In the same manner as in Example 1, the sealer layer 3a is provided on the building substrate 2a, the undercoat coating layer 4a is provided on the sealer layer 3a, and the overcoat coating layer 5a is provided thereon.

Next, to 100 parts by weight of a transparent acrylic resin emulsion (solid content 50% by weight), 2.0 parts by weight of spherical acrylic resin beads (average particle size 70 μm) were added,
Stir until it becomes almost uniform to produce a clear paint, and apply this clear paint with an air spray coating machine at a coating amount of 130 g.
/ M ² and then dried in the same manner as in Example 1 to form a clear layer 6a, thereby manufacturing a decorative board 1a for construction.

(Evaluation) The decorative decorative boards 1, 1a (thickness: 15 mm) manufactured in Examples 1 and 2 are excellent decorative materials for outer wall, which are excellent in design and weight and have moderate luster. . In addition, the architectural decorative boards 1, 1a are concealing layers 42,
Since the pigment contained in 42a and the pigment contained in the top coating layer 5, 5a are substantially the same, it is difficult to distinguish the hiding layers 42, 42a from the top coating layer 5, 5a, and the hiding layer 42 , 42a and the pigments contained in the top coating layers 5, 5a make the surfaces of the building substrates 2, 2a invisible and are very beautiful decorative boards for construction 1, 1a.

Further, the thickness of the overcoat coating layers 5, 5a can be reduced only by the hiding by the hiding layers 42, 42a, the amount of expensive coloring paint can be reduced by that much, and the architectural decorative boards 1, 1a. Can be manufactured at low cost. Further, a test piece having a size of about 70 mm × about 150 mm was taken from the architectural decorative materials 1 and 1a, and the glossiness of the test piece was measured to be 3.6 and 5.7.

Next, this test piece was tested at Miyakojima in accordance with JIS-
An outdoor exposure test was conducted for 2 years in accordance with the method shown in Z-2381 (general rules for outdoor exposure test method). The test results show that the decorative sheets 1 and 1a for construction shown in Examples 1 and 2 have a gloss of 2.6 and 4.3, which are slightly less glossy than before the outdoor exposure test, but with the naked eye. It is a decorative veneer for construction, which is almost indistinguishable, has no chalking, and has excellent weather resistance.

(Embodiment 3) FIGS. 4 to 7 show another embodiment of the present invention. FIG. 4 is a perspective view of a decorative board for construction, and FIG.
4 is a sectional view taken along the line BB in FIG. 4, FIG. 6 is a front view showing a state in which an overcoat coating layer is provided on an inkjet printer type coating machine, and FIG. 7 is a side view of FIG.

In FIGS. 4 to 7, reference numeral 1b is a decorative board for construction, and the decorative board 1b for construction is a building of a calcium silicate board having unevenness of a tile pattern on the surface as shown in FIGS. 4 and 5. Substrate 2b, sealer layer 3b provided on the entire surface thereof, undercoat coating layer 4b provided on this sealer layer 3b, and undercoat coating layer 4b provided on the convex portion of the tile pattern. It comprises an overcoat coating layer 5b, a topcoat coating layer 5b provided on the convex portion of this tile pattern, and a clear layer 6b provided on the undercoat coating layer 4b provided in the concave portion. The undercoat coating layer 4b is composed of an undercoat main material layer 41b and a masking layer 42b.

Reference numeral 8b is an ink jet printer type coating machine, and this ink jet printer type coating machine 8b is a device as shown in FIGS. That is, the inkjet printer type coating machine 8b is provided with a conveyor 81b for carrying and carrying the building substrate 2b provided with the sealer layer 3b and the undercoat coating layer 4b, and the printer mounted above the conveyor 81b. At the lower end of the head 82b and the printer head 82b, a plurality of nozzles 83b provided in the entire width direction of the conveyor 81b are arranged in parallel downward at a pitch of 3 mm. The diameter of this nozzle 83b is 0.3.
mm.

A paint tank 85b is connected to the printer head 82b, and the paint 86 in the paint tank 85b is connected to the paint tank 85b.
b can be sent to the printer head 82b by a pump 87b and a relief valve 88b. 9b
Is a valve control device, and this valve control device 9b is
The valve 91b for opening and closing each nozzle 83b of the printer head 82b can be individually controlled.

Reference numeral 92b is pattern data in which a color tone pattern corresponding to the color tone to be painted is input. 93
Reference numeral b is a computer that issues a control signal to the valve control device 9b based on the pattern data 92b input in advance.

Reference numeral 94b is a photoelectric tube type sensor consisting of a projector 941b and a light receiver 942b provided on both sides of the conveyor 81b. The photoelectric tube type sensor 94b is
The building board 2b being conveyed by the conveyor 81b is detected, and the signal detected by the photoelectric tube type sensor 94b is transmitted to the computer 93b. 95
Reference numeral b is an encoder connected to the drive roll 811b of the conveyor 81b, and is adapted to transmit a pulse to the computer 93b at every minimum rotation angle, for example, every 360/2000 minimum rotation angle.

Next, a method of manufacturing the decorative decorative board 1b will be described. (Production of Sealer) A cooled diphenyl methane diisocyanate compound was dissolved in a mixed solvent (butyl acetate / xylene = 1/1) to give a solid content of 15.
Produce 0% sealer.

(Production of Undercoat Paint) 3 parts of an acrylic resin varnish containing an alkoxysilyl group (Kanefuchi Chemical Industry Co., Ltd., trade name “Zemlac AM1532”, NV: 51 ± 3%)
8.5 parts by weight, titanium white 10.3 parts by weight, iron oxide yellow 0.15 parts by weight, carbon black 0.15 parts by weight,
3.1 parts by weight of mica, 6.2 parts by weight of barium sulfate,
Butyl acetate 15.3 parts by weight, xylene 15.3 parts by weight, organic carboxylic acid ester 0.8 parts by weight, organic tin compound solvent solution 3.1 parts by weight are mixed almost uniformly to produce an undercoat paint. To do.

(Manufacture of hiding paint) Alkoxysilyl group-containing acrylic resin varnish (Kanefuchi Chemical Industry Co., Ltd., trade name "Zemlac AM1532", NV: 51 ± 3%) was used.
5 parts by weight, titanium white 17.3 parts by weight, iron oxide yellow 0.
15 parts by weight, iron oxide rust 0.1 parts by weight, iron oxide red rust 0.1 parts by weight, carbon black 0.15 parts by weight, mica 3.1 parts by weight, barium sulfate 6.2 parts by weight, Butyl acetate (15.3 parts by weight), xylene (15.3 parts by weight), organic carboxylic acid ester (0.8 parts by weight), and organic tin compound solvent solution (3.1 parts by weight) were mixed substantially uniformly to produce a hiding paint. To do.

(Production of Colored Paint) 2.9 parts by weight of terpen soluble acrylic resin varnish (manufactured by Dainippon Ink and Chemicals, Inc., trade name "Acridic 56-1128", NV: 50 ± 2%), terpen 11.5 parts by weight of soluble type alkoxysilyl group-containing acrylic resin varnish (manufactured by Japan Yupica, trade name "Yupica coat B2928", NV: 60 ± 2%), 0.5 parts by weight of red iron oxide, and carbon black 1.0 parts by weight, toluene 17.6 parts by weight, isopropyl alcohol 0.2 parts by weight, rubber volatile oil (specific evaporation rate 100) 66.1 parts by weight, organic carboxylic acid ester 0.2 parts by weight. Mix almost uniformly to obtain a viscosity of 5.7 cP (20
) To produce a colored paint.

(Production of clear coating) Alkoxysilyl group-containing fluororesin copolymer resin varnish (manufactured by Daikin Industries, Ltd., trade name "Zeffle 420S-2", NV: 57-6)
2%), 23 parts by weight of an alkoxysilane group-containing acrylic copolymer resin varnish (manufactured by Nippon Yupica Co., Ltd., trade name "Yupicacoat B3027", NV: 53%), 26 parts by weight of isopropyl alcohol and water. 0.26 parts by weight are mixed and hydrolyzed by stirring at 20 ° C. for 3 hours.

Next, ethyl silicate was added to this solution.
By weight, 0.25 parts by weight of water, 0.1 parts by weight of acetylacetone aluminum and 0.1 parts by weight of ethoxyboron are mixed and stirred at 20 ° C. for 2 hours to obtain a blend. 100 parts by weight of this compound, and the product name "KBM # 603"
By weight, 20 parts by weight of xylene, 20 parts by weight of butyl acetate and 10 parts by weight of isopropyl alcohol are uniformly mixed to produce a clear paint.

(Manufacturing of a decorative board for construction) A sealer was coated on a construction substrate 2b having a tile pattern unevenness on the surface with an airless spray coating machine to a coating amount of about 70 g / m ² (wet).
So that the entire surface is coated with the sealer layer 3b on the surface of the building substrate 2b. Next, this sealer layer 3b
The undercoat paint is applied to the entire surface by an airless spray coater so that the applied amount is about 80 g / m ² (wet), and dried to provide the undercoat main material layer 41b on the sealer layer 3b. .

Next, on the undercoating main material layer 41b, an airless spray coating machine was used to coat the hiding paint with an amount of about 30 g.
/ M ² (wet), the whole surface is coated and dried to provide a concealing layer 42b on the undercoating main material layer 41b. In this way, the undercoat main material layer 41b and the hiding layer 42
An undercoat coating layer 4b consisting of b is provided.

Next, an overcoat coating layer 5b is provided on the undercoat coating layer 4b on the convex portion of the tile pattern by an ink jet printer type coating machine. A method for providing the top coat layer 5b with this inkjet printer type coating machine will be described in detail. The colored paint is put in the paint tank 85b in advance, the pump 87b is operated, and the valve control device 9 is operated from the nozzle 83b of the printer head 82b.
When the valve 91b is opened at b, the colored paint is sprayed.

When the building substrate 2b provided with the sealer layer 3b and the undercoat coating layer 4b (hereinafter referred to as the building substrate 2b) is placed on the conveyor 81b, it passes under the printer head 82b. When the tip of the building board 2b passes in front of the phototube sensor 94b, the phototube sensor 94b detects that the building board 2b has arrived and sends a detection signal to the computer 93b. On the other hand, as the conveyor 81b moves, the drive roll 8
A pulse is transmitted to the computer 93b from an encoder 95b provided in 11b.

The computer 93b starts counting the pulses by the signal from the photoelectric tube type sensor 94b, and when the number of pulses reaches a preset area stored in advance,
Depending on the number of pulses, a control signal based on the pattern data 92b of the color tone pattern input in advance is sequentially instructed to be transmitted to the valve control device 9b, whereby the valve control device 9b individually controls the opening and closing of the valve 91b, and the valve 91b. When is opened, the colored paint on the printer head 82b is sprayed from the nozzle 83b onto the building substrate 2b, and the color tone based on the pattern data 92b is applied to the convex portion of the tile pattern. In this way, the amount of color paint applied is approximately 22 g / m.
² is applied to the convex portion of the tile pattern and dried to form the top coating layer 5b on the under coating layer 4b.

As described above, since the overcoat coating layer 5b is provided by the ink jet printer type coating machine 8b, the colored paint can be provided in a predetermined thickness only on the convex portions of the tile pattern on the surface, and the expensive colored paint is lost. It can be painted beautifully. Then, an airless spray coating machine is used to coat the overcoat coating layer 5b coated on the convex portion of the tile pattern and the undercoat coating layer 4b coated on the concave portion of the tile pattern with the coating amount of the concealment coating material. The clear layer 6 is coated and dried to a weight of about 70 g / m ² (wet).
b is provided.

(Evaluation) The architectural decorative board thus obtained has a color difference between the convex portion and the concave portion of the tile pattern, and it looks as if the tiles of high-grade pottery were stuck on the entire surface, which was extremely high-grade. The appearance can be obtained and this architectural decorative board 1b
Is a pigment contained in the hiding layer 42b (titanium white, iron oxide yellow,
As iron oxide rust, iron oxide red, carbon black) and the pigment (iron oxide red, carbon black) contained in the top coat layer 5b, iron oxide red and carbon black with dark colors are almost the same, Concealment layer 42b and top coat layer 5
It is difficult to distinguish it from b, and the surface of the convex portion of the tile pattern of the building board 2b cannot be seen due to the pigment contained in the concealing layer 42b and the top coating layer 5b. 1, 1a.

Next, with respect to the hot water resistance measured by JIS-K-5400, there was no change when the test piece was immersed in tap water at 60 ° C. for 7 days and the abnormality of the coating film was visually observed. Regarding the weather resistance, the test piece was left to stand for 3000 hours with a sunshine weather-autometer, but there was no change in the appearance of the coating film.
%Met. Further, frost damage resistance was measured by the ASTM-C666A method, but no crack was generated. In this way, this architectural decorative board 1b has extremely good properties.

(Embodiment 4) FIGS. 8 and 9 show still another embodiment of the present invention. FIG. 8 (a) is a front view of a decorative board for construction, and (b) is C of (a). FIG. 9 is a perspective view of a portion, and FIG. 9 is a side view showing a state in which an overcoat coating layer is provided on an inkjet printer type coating machine.

Embodiment 4 shown in FIGS. 8 and 9 is shown in FIGS.
In comparison with Example 3 shown in FIG.
The difference is that these three kinds of colored paints are separately applied to the convex portions of the tile pattern of the building substrate 2c having a tile pattern surface to form a beautiful architectural decorative board 1c having a spot pattern. Therefore, this different part will be mainly described. Three different types of colored paints are used for the inkjet printer type coating machine 8b.

That is, the three types of colored paints are separately stored in the paint tanks 85c-1, 85c-2, 85c-3. Also, the printer heads 82c-1 and 82c
c-2 and 82c3 are provided side by side in three rows in the traveling direction. And each printer head 82c-
A plurality of nozzle groups 83c are provided at 1, 82c-2, 82c3.
-1, 83c-2, 83c-3 are attached.

Then, the colored paint in the paint tank 85c-1 is supplied from the first printer head 82c-1 to the first nozzle group 83c-1, and the colored paint in the paint tank 85c-2 is supplied to the second printer head 82c. -2 to the second nozzle group 83c-2, and the colored paint in the paint tank 85c-3 is supplied from the third printer head 82c to the third nozzle group 83c-3.

Next, the manufacturing method and operation of the architectural decorative board 1c using this ink jet printer type coating machine 8c will be described. When the method shown in this Example 4 is compared with the method shown in Example 3, the colored paints in the paint tanks 85c-1, 85c-2, 85c-3 are based on the pattern data of the color tone pattern input in advance. The difference is that the nozzles 83d-1, 83d-2, and 83d-3 are sprayed onto the building substrate 2b, and the color tone based on the pattern data 92c is applied to the convex portion of the tile pattern. Since the other points are substantially the same as those in the third embodiment, the description thereof will be omitted.

In this way, the architectural decorative board 1c manufactured by the ink jet printer type coating machine 8b is
As shown in FIG. 9, portions 99c-1, 99c-2, and 99c-3 colored with three kinds of colored paint on the convex portion of the tile pattern.
However, it is a very beautiful architectural decorative board 1c in which exactly three types of tiles are scattered and applied in a spotted pattern.

As described above, since the top coating layer 5b is provided by the ink jet printer type coating machine 8b, a plurality of colored paints can be provided in a predetermined thickness only on the convex portion of the tile pattern on the surface. It is possible to paint without any loss, and it is possible to manufacture an extremely beautiful decorative board for construction 1c having an appearance in which three types of tiles of different colors are attached in a spot pattern.

[0102]

As described in detail above, according to the first aspect of the invention, the undercoating paint is applied to the surface of the building substrate to form the undercoating main material layer, and the hiding paint is applied on this to form the hiding layer. As, the undercoat coating layer consisting of this undercoat main material layer and the hiding layer is provided, and since the topcoat coating layer is formed by applying the coloring paint on this undercoating layer, the hiding layer and the coloring paint coated with the hiding paint are provided. The applied top coat layer makes it difficult to see the surface of the building board from above the building decorative board,
You can obtain a beautiful architectural veneer, and the surface of the architectural veneer is hard to see due to this concealment layer, so the thickness of the expensive top coat layer can be made thinner than before, and It can be manufactured at low cost.

According to the second aspect of the present invention, since the method of forming the overcoat coating layer is a method of applying the colored coating material with an ink jet printer type coating machine, the required colored coating material is applied in a predetermined thickness only in a necessary place on the surface. It can be painted and a beautiful decorative board for construction can be obtained, and the loss of time and the loss of paint can be minimized when changing colors or changing coating conditions.

According to the third aspect of the present invention, since the hiding paint is composed of the undercoating paint and a pigment substantially the same as the pigment contained in the coloring paint, the hiding paint and the undercoating paint have good adhesion and hiding power. It becomes difficult to distinguish the paint from the colored paint in the top coating layer, and the almost same pigment contained in the concealing paint and the top coating layer makes it possible to efficiently see the surface of the building board from the surface of the building decorative board. Can be difficult.

According to a fourth aspect of the present invention, a method of providing an undercoat coating layer is such that an undercoat paint passage, a pigment injection passage opened at the tip of the undercoat paint passage, an undercoat paint passage and a tip of the pigment injection passage. Using a coating machine equipped with a head consisting of a mixing section provided on the
The undercoat paint that has passed through the undercoat paint passage and the mixing section is applied to form the undercoat main material layer.Next, the undercoat paint that has passed through the undercoat paint passage and the pigment that has passed through the pigment injection path are made substantially uniform in the mixing section. This is a method of mixing to form a hiding paint, and this hiding paint is applied to form a hiding layer.Therefore, the undercoating main material layer and the hiding layer can be provided with the same coating machine, and switching from the undercoating paint to the hiding paint It goes smoothly and there is less loss of undercoat and concealment paint.

In the invention of claim 5, the undercoating main material layer is 70 to 90% of the thickness of the undercoating coating layer, and the concealing layer is 30 to 10% of the thickness of the undercoating coating layer. Even if it is not increased, sufficient concealing property can be obtained, the amount of expensive pigment can be reduced, and the decorative veneer for construction can be manufactured at low cost.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, in which (a) is a perspective view showing a decorative board for construction, and (b) is a sectional view taken along line AA of (a).

FIG. 2 is a cross-sectional view showing a head of an air spray type coating machine used when providing an undercoat coating layer.

FIG. 3 shows another embodiment of the present invention and is a sectional view showing a part of a decorative board for construction.

FIG. 4 shows another embodiment of the present invention and is a perspective view of a decorative board for construction.

5 is a cross-sectional view taken along the line BB of FIG.

FIG. 6 is a front view showing a state in which an upper coating layer is provided on an inkjet printer type coating machine.

FIG. 7 is a side view of FIG.

FIG. 8 shows still another embodiment of the present invention, in which (a)
Is a front view of a decorative board for construction, and (b) is a perspective view of a portion C of (a).

FIG. 9 is a side view showing a state in which a top coating layer is provided on an inkjet printer type coating machine.

FIG. 10 is a front view showing a state in which paint is being applied by a conventional inkjet printer type coating machine.

11 is a side view of FIG.

[Explanation of symbols]

1, 1a, 1b, 1c Decorative board for construction 2, 2a, 2b, 2c Building board 3, 3a, 3b sealer layer 4, 4a, 4b Undercoat coating layer 41, 41a, 41b Undercoat main material layer 42, 42a, 42b Hiding layer 5, 5a, 5b, 5c Top coat layer

Continued front page    F-term (reference) 4D075 AC06 AC09 AE03 AE27 BB16Y                       BB92Y CA32 CA38 CB04                       CB07 CB36 DA06 DA07 DB02                       DB04 DB07 DB12 DB38 DB43                       DC01 EA06 EA07 EA13 EA43                       EB13 EB14 EB15 EB16 EB19                       EB22 EB32 EB33 EB36 EB38                       EB43 EC11

Claims (5)

[Claims] 1. An undercoat coating layer comprising a base material layer and a hiding layer, the undercoating material being applied to the surface of a building substrate to form an undercoating main material layer, and the hiding coating being applied thereon to serve as a hiding layer. And a colored paint is applied on the undercoating layer to form a topcoating layer. 2. The method for manufacturing a decorative board for construction according to claim 1, wherein the method of providing the top coating layer is a method of applying a colored coating material with an inkjet printer type coating machine. 3. The method for manufacturing a decorative board for construction according to claim 1, wherein the concealing paint comprises a pigment which is substantially the same as the pigment contained in the undercoat paint and the coloring paint. 4. The method of providing the undercoat coating layer comprises: an undercoat paint passage, a pigment injection passage opening at the tip of the undercoat paint passage, and a mixing provided at the tip of the undercoat paint passage and the pigment injection passage. Using a coating machine equipped with a head consisting of a part and a part, apply the undercoat paint that has passed through the undercoat paint passage and the mixing part to the surface of the building substrate to form the undercoat main material layer, and then pass through the undercoat paint passage. 2. The method of mixing a subbing paint prepared as described above and a pigment which has passed through a pigment injection passage substantially uniformly in a mixing section to form a hiding paint, and applying the hiding paint to form a hiding layer. For manufacturing a decorative veneer for a building. 5. The undercoating main material layer is 70 to 90% of the thickness of the undercoating coating layer, and the concealing layer is 30 to 10% of the thickness of the undercoating coating layer. Manufacturing method of decorative board for construction.