JP2005162825A - Emulsion coating and method for producing inorganic decorative plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an emulsion coating which has good film formability, less liable to cause a blocking phenomenon, even when coated articles are highly loaded just after coated and dried, and can form coating films having excellent weather resistance and antifoulancy, and to provide a method for producing an inorganic decorative plate which uses the emulsion coating, less liable to cause a blocking phenomenon, even when coated articles are highly loaded just after coated and dried, and has excellent weather resistance and antifoulancy. <P>SOLUTION: This emulsion coating is characterized by containing a water-diluting synthetic resin emulsion in an amount of 95 to 45 mass % based on the solid content as a binder component and containing colloidal silica in an amount of 5 to 55 mass % based on the solid content. A method for producing an inorganic decorative plate, comprising forming a lower coating layer on the surface of an inorganic substrate and forming a surface coating film layer on the surface of the lower coating layer, is characterized by forming the surface coating film layer with the emulsion coating. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an emulsion paint and a method for producing an inorganic decorative board used as a building interior material or exterior material. More specifically, the film forming property is good, and even when a coated material immediately after coating and drying is highly loaded, blocking is performed. Phenomenon that does not easily occur, and can further form a coating film excellent in weather resistance and stain resistance, and by using the emulsion paint, it is excellent in blocking resistance even when highly loaded immediately after coating and drying. Furthermore, it is related with the manufacturing method of the inorganic decorative board excellent in the weather resistance and contamination | pollution property.

  Conventionally, organic solvent-diluted acrylic paints and acrylic urethane paints have been widely used as manufacturing methods for building interior materials and exterior materials of this type. However, environmental problems such as sick house syndrome and the diffusion of organic solvents into the atmosphere, etc. Therefore, the conversion to water-diluted paint is progressing at an accelerated pace. On the other hand, consumer needs have shown a significant increase in expectations for the long-term durability of these products.

  Considering the characteristics of the water-diluted emulsion paint under such circumstances, it is most important that the paint achieves good film formation. Regarding the coating film formation, the volume shrinkage proceeds with the volatilization of the solvent after the coating, and the distance between the emulsion particles simultaneously decreases, finally the closest packing of the particles occurs, and then the particles are fused. In order to achieve good film formation in such film formation, it is desirable that the glass transition point (or film forming temperature) of the polymer in the emulsion is low. If a good film is not formed, it becomes a defective film in which the film is cracked in a short time during practical use at a low temperature, or a film lacking the water permeation preventing ability.

  On the other hand, it is an inevitable production condition for building interior materials and exterior materials to be highly loaded immediately after the formation of the coating film (in a state where the plate temperature is high immediately after coating and drying). However, the water-diluted emulsion paint uses a low glass transition point (or film-forming temperature) as the polymer in the emulsion as described above from the viewpoint of ensuring film-forming properties, so that such production conditions are met. In many cases, it cannot be adequately handled, and when it is highly loaded as described above, indentation of the coating surface film, adhesion between the coating surface and the back surface of the substrate, or adhesion between the coating surfaces occurs, and it is applied when peeling off. Damage such as film peeling (so-called blocking phenomenon) often occurs. In order to eliminate such problems, it is essential that the polymer in the emulsion has a high glass transition point. As described above, the water-diluted emulsion paint is required to have completely opposite properties at the time of film formation and after the film formation.

  As a technical method corresponding to these completely contradictory properties, emulsions having a two-layer structure in which the outer shape of the particles in the emulsion is a low glass transition polymer and the inside of the particles is a high glass transition polymer, for example, a so-called core-shell structure emulsion (for example, And hydrazine compounds having a hydrazine residue, hydrazide residues having a hydrazide residue, or hydrazone compounds having a hydrazone residue. A crosslinkable emulsion (for example, see Patent Documents 4 to 5) that undergoes a crosslink reaction inside or between particles by a combination or the like is known, but has not yet satisfied both of the contradictory properties.

JP 2003-226835 A Japanese Patent Laid-Open No. 11-092708 Japanese Patent Laid-Open No. 11-090325 JP 2000-017198 A JP-A-08-117333

  The present invention has been made against the background of the problems of the prior art as described above, has good film-forming properties, does not easily cause a blocking phenomenon even when the coated material immediately after coating and drying is highly loaded, and is weather resistant. Emulsion paint that can form a coating film with excellent properties and stain resistance, and by using the emulsion paint, it is excellent in blocking resistance even if it is highly loaded immediately after coating and drying, and further in weather resistance and stain resistance It aims at providing the manufacturing method of the outstanding inorganic decorative board.

  As a result of repeating various studies to achieve the above object, the present inventors have achieved the above object by using a water-dilutable synthetic resin emulsion and colloidal silica as a binder component in a specific ratio. As a result, the present invention has been completed.

  That is, the emulsion paint of the present invention contains 95 to 45% by mass of a water-dilutable synthetic resin emulsion as a binder component based on the solid content and 5 to 55% by mass of colloidal silica based on the solid content. To do.

  Moreover, the manufacturing method of the inorganic decorative board of this invention forms a lower coating film layer on the surface of an inorganic base material, and manufactures the inorganic decorative board which forms a surface coating film layer on the surface of this lower coating film layer. In the method, the surface coating layer is formed using the emulsion paint of the present invention.

  The emulsion paint of the present invention has a good film formability, and even if the coated material immediately after coating and drying is highly loaded, it is difficult to cause a blocking phenomenon, and further, it forms a coating film having excellent weather resistance and stain resistance. Can do. In addition, the method for producing an inorganic decorative board of the present invention can produce an inorganic decorative board that is excellent in blocking resistance even when highly loaded immediately after coating and drying, and further excellent in weather resistance and stain resistance.

The present invention will be specifically described below.
The emulsion paint of the present invention contains a water-dilutable synthetic resin emulsion and colloidal silica as a binder component, and even if the coated product immediately after coating and drying is highly loaded without impairing the film formability of the emulsion varnish. It is difficult to cause a blocking phenomenon, and it is possible to form a coating film having excellent weather resistance and stain resistance.

  Regarding the binder component of the emulsion paint of the present invention, it is essential that the water-dilutable synthetic resin emulsion is contained in an amount of 95 to 45% by mass based on the solid content and the colloidal silica is contained in an amount of 5 to 55% by mass based on the solid content. . When a surface coating layer is formed using an emulsion coating with a colloidal silica content of less than 5% by weight based on the solid content of the binder component, the coating immediately after drying is insufficient because of insufficient blocking resistance. If the coated material immediately after drying is highly loaded, adhesion of the surface coating layer occurs, and there is a risk that damage such as peeling of the coating film occurs when it is peeled off. In this respect, the colloidal silica content is preferably 10% by mass or more based on the solid content of the binder component. Further, when the surface coating layer is formed using an emulsion paint having a colloidal silica content of more than 55% by mass based on the solid content of the binder component, the resulting surface coating layer has flexibility, feeling of flesh or water permeation inhibiting ability. Tends to decrease, which is not preferable. In this respect, the colloidal silica content is preferably 45% by mass or less based on the solid content of the binder component.

  In the emulsion paint of the present invention, it is preferable to use a copolymer of α and β unsaturated monomers as the water-dilutable synthetic resin emulsion, and representative examples thereof include vinyl acetate type, ethylene-vinyl acetate type. , Vinyl acetate-acrylic, styrene-acrylic, acrylic, acrylic silicon, acryl-fluorinated vinyl, fluorine-containing vinyl, and silicon-modified fluorine-containing vinyl. In addition, these synthetic resin emulsions include various types that have been conventionally used, such as those having a multilayer structure such as a core / shell structure, and those having a crosslinkable type by a combination of a carbonyl group-containing resin and a compound having a hydrazine residue. These synthetic resin emulsions can be used without any limitation. These synthetic resin emulsions may be single synthetic resin emulsions or a mixture of two or more synthetic resin emulsions. However, the ionicity of the emulsion is particularly preferably an anionic, nonionic or anionic-nonionic from the viewpoint of mixing stability with colloidal silica.

In the emulsion paint of the present invention, the colloidal silica is preferably such that the silica component particles of the colloidal silica are granular or pearl-like, and more preferably have a particle diameter in the range of 7 to 100 nm. For example, it is useful to use a dispersion obtained by colloidally dispersing anhydrous silicic acid ultrafine particles having a particle diameter in the range of 7 to 100 nm and having a SiO ₂ content of preferably 15 to 45% by mass. Can do. Further, as colloidal silica, those having an alkali side with a pH of 8.4 to 11.5 are excellent in miscibility with a synthetic resin emulsion (having an ionicity of anion to nonion) and storage stability after mixing. Therefore, it is preferable. When the colloidal silica has a pH of less than 8.4, particularly an acidic side, gelation or the like is caused in a short time when mixed with the ionic synthetic resin emulsion, and the stability tends to deteriorate. When the colloidal silica has a pH exceeding 11.5, the amount of the water-soluble component that is separated from the obtained surface coating layer increases, and the performance such as water resistance tends to decrease. The pH of the colloidal silica is more preferably in the range of 9.0 to 10.5 from the limitation of mixing stability and water-soluble content.

  In addition, when colloidal silica is mixed and used for a synthetic resin emulsion, the surface hydrophilicity of the obtained coating film may increase more than expected, and the tendency for warm water resistance and a weather resistance to fall may be seen. As a countermeasure against such a case, a synthetic resin emulsion having a carboxyl group is mixed with a so-called amino silane coupling agent in which one end of the molecule is an amino group and the other end is an alkoxysilyl group. After neutralization, the use of a paint having colloidal silica added therein eliminates the decrease in hot water resistance and weather resistance, but rather improves it.

  In addition, as a particle dispersion state of colloidal silica, it is common to use a particle in which individual particles are in an independent dispersion state, but spherical particles of 10 to 50 nm have a length of 50 to 400 nm like a pearl necklace. A series of so-called pearl-like ones can also be used effectively. The pearl-like one is preferred in that a tendency of excellent film formability to be observed as compared with a case where individual particles are independently dispersed.

  The emulsion paint of the present invention can contain pigments and other various additives other than these binder components. Furthermore, the state of the surface coating film formed using the emulsion paint of the present invention may be in various forms from transparent to colored translucent to colored hiding. When the surface coating layer is formed using the emulsion paint of the present invention on the lower coating layer (a) or the lower coating layer (b) described later, the lower coating layer containing a coloring pigment or the like is used. It is used as a water-diluting paint in a so-called solid color form. When the surface coating layer is formed using the emulsion paint of the present invention on the lower coating layer (b), the lower coating layer (c) or the lower coating layer (d), the lower coating layer is It is used as a water-diluted paint in which a transparent or translucent clear or colored clear film is formed that is visible.

  In the emulsion paint of the present invention, known pigments can be used in a wide range for paint applications. Typical pigments include titanium oxide, iron oxide, composite oxides (nickel / titanium, chromium / titanium, bismuth / vanadium), carbon black and other inorganic color pigments, quinacridone, diketopyrrolopyrrole, Organic pigments such as benzimidazolone, isoindolinone, anthrapyrimidine, phthalocyanine, selenium and dioxazine, and extender pigments such as calcium carbonate, barium sulfate, kaolin, mica and talc can be mentioned.

  In the emulsion paint of the present invention, as a pigment or aggregate that can be added mainly for the purpose of adjusting the glossiness of the clears or imparting design properties, silicon oxide, polyacrylonitrile, polymethylmethacrylate Examples include transparent or colored plastic beads such as polyurethane and polyethylene, scale flakes such as aluminum flakes, metal-coated glass flakes, color-coated aluminum foil, and metal-coated mica, or fibrous pigments such as potassium titanate whiskers. Can do. Various modifications such as various pigment dispersants, suspending agents, UV absorbers, light stabilizers, film forming aids, thickeners, surface conditioners, antiseptic / antifungal agents, antifoaming agents, etc. It is also possible to mix the agent as appropriate.

  In addition, when forming a surface coating film layer using the emulsion paint of the present invention on the lower coating film layer (a) or the lower coating film layer (b) described later, the total solid content standard of the binder component and the pigment And binder component: pigment = 75 to 30% by mass: preferably 25 to 70% by mass. When the amount of the pigment is less than 25% by mass based on the total solid content of the binder component and the pigment, the concealability of the coating film formed using such an emulsion paint tends to be insufficient. Further, when the amount of the pigment exceeds 70% by mass based on the total solid content of the binder component and the pigment, the weather resistance and water permeation inhibiting ability of the coating film formed using such an emulsion paint tend to be reduced. is there. Therefore, the amount of the pigment is more preferably 35 to 65% by mass based on the total solid content of the binder component and the pigment.

  When forming the surface coating layer on the lower coating layer (b), the lower coating layer (c) or the lower coating layer (d) using the emulsion paint of the present invention, a binder component and a pigment are used. It is preferable that it is binder component: pigment = 99-55 mass%: 1-45 mass% on the basis of total solid content. When the amount of the pigment is less than 1% by mass on the basis of the total solid content of the binder component and the pigment, gloss adjustment and designability imparting of a coating film formed using such an emulsion paint are insufficient. When the amount of the pigment exceeds 45% by mass based on the total solid content of the binder component and the pigment, the coating film formed using such an emulsion paint has a concealing property, and the lower layer coating is formed. The visibility of the film layer tends to be lost. Therefore, the amount of the pigment is more preferably 5 to 40% by mass based on the total solid content of the binder component and the pigment. .

  As an inorganic base material used in the method for producing an inorganic decorative board of the present invention, flexible boards, calcium silicate boards, gypsum slag perlite boards, wood chip cement boards, precast concrete boards, ALC boards, gypsum boards, etc. The various inorganic board currently mentioned can be mentioned, They can be especially used without a restriction | limiting.

As representative examples of the lower coating layer formed on the substrate, the following lower coating layers (a) to (d) in various forms can be mentioned.
As the lower layer coating film layer (a) of the first example, there can be mentioned one obtained by first applying only an undercoat to the substrate. The purpose of the undercoat is to ensure adhesion to the substrate and at the same time to ensure interlayer adhesion to the surface coating layer (or the next process film). As an undercoat used for the formation of the lower coating layer (a), an isocyanate prepolymer type, an epoxy resin type, an acrylic resin type or the like each alone or a mixed solution of two or more of these, or an isocyanate compound and a polyol A mixture of epoxy resin, epoxy resin, acrylic resin, alkali silicate, or the like, or a water dilution type of a mixture of two or more of these can be used effectively. From the above, a water dilution type having a small amount of solvent volatilization is more preferable. Further, as these undercoat paints, those having no pigment at all and those containing a large amount of pigment can be used mainly for the purpose of quality such as the strength of the base material and the finished appearance of the decorative decorative board.

As pigments that can be used in the above-mentioned undercoat paint, a wide range of known pigments can be used for paint applications. Typical pigments include inorganic color pigments such as titanium oxide, iron oxide, and carbon black, organic color pigments such as phthalocyanine blue, Hansa Yellow, and permanent red, as well as calcium carbonate, barium sulfate, kaolin, mica, and talc. The extender pigments can be mentioned. In such undercoat paint, it is preferable that resin: pigment = 100-30% by mass: 0-70% by mass based on the total solid content of the resin and pigment of the undercoat paint. The lower coating layer (a) is prepared by applying a conventional coating method, such as an airless spray, a roll coater, a flow coater, a shower coater and an air knife. For example, a wet coating amount of 35 to 100 g / m ² can be applied and dried at a temperature of 60 to 130 ° C. for 30 seconds to 5 minutes.

  The lower coating layer (b) of the second example is obtained by further forming an intermediate coating layer on the lower coating layer (a). The purpose of the intermediate coating layer is to ensure the feeling of fleshiness and smoothness of the decorative plate obtained by the production method of the present invention, or the interlayer adhesion with the surface coating layer, and in some cases, the decorative plate It is to determine the finished color. As the intermediate coating material used for forming the intermediate coating layer, known coating materials used for building materials can be widely used. Typical examples of the paint include vinyl acetate-based, acrylic-based, acrylic urethane-based, acrylic silicon-based resins, or a solvent solution or a water-diluted paint of a mixture of two or more types. Of course, from the viewpoint of environmental problems, a water dilution type paint is more preferable. Further, these intermediate coatings can be used from those containing no pigment to those containing a large amount of pigment.

As pigments that can be used in the above-mentioned intermediate coating, a wide range of known pigments can be used for coating applications. Typical pigments include titanium oxide, iron oxide, composite oxides (nickel / titanium, chromium / titanium, bismuth / vanadium), carbon black and other inorganic color pigments, quinacridone, diketopyrrolopyrrole, Organic pigments such as benzimidazolone, isoindolinone, anthrapyrimidine, phthalocyanine, selenium and dioxazine, and extender pigments such as calcium carbonate, barium sulfate, kaolin, mica and talc can be mentioned. In such an intermediate coating, it is preferable that resin: pigment = 70-25% by mass: 30-75% by mass based on the total solid content of the resin and pigment of the intermediate coating. The intermediate coating film has a wet coating amount of 55 by applying a conventional coating method such as an airless spray, a roll coater, a flow coater, etc., to the intermediate coating having a heating residue of approximately 25 to 65% by mass at the time of coating. It can apply | coat so that it may become -130g / m < ² >, and it can dry and form for 40 seconds-5 minutes under the temperature of 60-130 degreeC.

The lower layer coating layer (c) of the third example is formed on the convex portion only by using the embossed shape provided on the surface of the base material on the intermediate coating layer of the lower layer coating layer (b). Painted in a different color from the intermediate coating layer. The purpose of this different color coating layer is to impart design properties to the decorative board. As the paint used for the formation of the different color coating layer, a paint having the same category as the paint used in the formation of the lower coating layer (b) can be used. However, the coating film formation process is different, and in many cases, only embossed convex portions are painted with a roll coater. This paint layer of different color is coated with a coating residue of approximately 30 to 70% by mass so that the wet coating amount is 20 to 70 g / m ² at a temperature of 60 to 130 ° C. It can be formed by drying for 40 seconds to 5 minutes. In some cases, a so-called wet-on-wet drying method that does not include a drying step between the following steps may be employed.

The lower layer coating layer (d) of the fourth example is obtained by further patterning the above lower layer coating layer (b) or (c) by various methods, and the purpose thereof is to design the decorative board. Is to grant. Typical examples of various patterning methods include flexographic printing, gravure offset printing, silk screen printing, thermal transfer printing, ink jet printing, and other printing methods and computer controlled paints from various nozzles. May be intermittently discharged and partially colored in a different color to form a pattern, and the ink or paint used for patterning is preferably an acrylic resin type or an acrylic silicon type from the viewpoint of durability or the like. However, in the case of ink, it may be used in a state in which a color pigment or the like is dispersed only with a dispersant and does not contain any resin. Color pigments used include titanium oxide, iron oxide, composite oxides (nickel / titanium, chromium / titanium, bismuth / vanadium), carbon black and other inorganic pigments, quinacridone, diketopyrrolopyrrole, Organic compounds such as benzimidazolone, isoindolinone, anthrapyrimidine, phthalocyanine, selenium and dioxazine, which are excellent in weather resistance, are preferable. These inks or paints having a heating residue of approximately 10 to 75% by mass are applied and patterned by various patterning techniques so that the wet coating amount is 10 to 50 g / m ² .

In the method for producing an inorganic decorative board of the present invention, the above-described emulsion paint of the present invention is applied to the surface of the lower coating layer formed as described above to form a surface coating layer.
As described above, when forming the surface coating layer using the emulsion paint of the present invention on the lower coating layer (a) or the lower coating layer (b), a coloring pigment or the like was blended. It is preferable to use it as a water-diluted paint having a so-called solid color that conceals the lower coating layer. When the surface coating layer is formed using the emulsion paint of the present invention on the lower coating layer (b), the lower coating layer (c) or the lower coating layer (d), the lower coating layer is It is preferably used as a water-diluted coating material on which a visible transparent or translucent clear or colored clear film is formed.

  In addition, as described above, when the surface coating layer is formed using the emulsion coating of the present invention on the lower coating layer (a) or the lower coating layer (b) described later, a binder component, a pigment, It is preferable that it is binder component: pigment = 75-30 mass%: 25-70 mass% on the basis of the total solid content. It is more preferable that the amount of the pigment is 35 to 65% by mass based on the total solid content of the binder component and the pigment.

  In addition, as described above, when the surface coating layer is formed on the lower coating layer (b), the lower coating layer (c) or the lower coating layer (d) using the emulsion coating of the present invention. The binder component: pigment = 99 to 55% by mass: 1 to 45% by mass based on the total solid content of the binder component and the pigment is preferable. It is more preferable that the amount of the pigment is 5 to 40% by mass based on the total solid content of the binder component and the pigment. .

In the method for producing an inorganic decorative board of the present invention, the emulsion paint of the present invention having a heating residue of approximately 15 to 60% by mass during coating is applied by a conventional coating method such as an airless spray, roll coater, flow coater, etc. It can apply | coat to the surface of a lower layer coating layer so that it may become 35-150 g / m < ² > of wet coating amount, and it can be made to dry for 40 seconds-15 minutes at the temperature of 60-160 degreeC, and an inorganic decorative board can be formed.

  The inorganic decorative board produced by the method for producing an inorganic decorative board of the present invention is excellent in blocking resistance even if it is highly loaded immediately after coating and drying of the coating film for forming a surface coating layer, and is also excellent in weather resistance and stain resistance. Has characteristics.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.
<Examples 1-5 and Comparative Examples 1-3>
In order to produce the building materials for the applications shown in Table 1, the base coat shown in Table 1 is applied to the surface of the base material of the type shown in Table 1, Examples 2-5 and Comparative Examples 2-3. The first intermediate coating shown in Table 1 was carried out on the undercoat, and Examples 4 to 5 and Comparative Example 3 were subjected to the second intermediate shown in Table 1 on the first intermediate coating. Coating was carried out, and for Example 5 and Comparative Example 3, patterning was carried out on the second intermediate coating, and finally, the top coating shown in Table 1 was carried out for all Examples and Comparative Examples. .

  Each of the undercoat, the first intermediate coat, the second intermediate coat, the patterning, the paint used in the top coat, the composition of the ink, and the coating conditions were as follows. In the following description, “parts” and “%” are based on mass.

<Undercoating 1>
Acrylic copolymer consisting of methyl methacrylate / butyl acrylate / styrene / acrylic acid = 45/31/22/2: 30 parts, titanium white: 5 parts, dispersant / film-forming aid / thickening agent, etc .: 7 parts Water: 58 parts of paint was applied with a double roll coater at a coating viscosity of 9 seconds / FC # 4 so that the coating amount was 60 g / m ² (wet), and then heat-treated at 100 ° C. for 70 seconds. A coating film was formed.

<Undercoating 2>
Epurgeon EA-7 (epoxy resin aqueous emulsion manufactured by Nippon NSC Co., Ltd., solid content 61 ± 1%, epoxy equivalent 300-340): 15 parts, Epurgeon EB-1 (modified NPS manufactured by Nippon NSC Co., Ltd.) Resin aqueous emulsion, solid content 40 ± 1%, amine value 107-108): 15 parts and water: 70 parts of paint with a coating viscosity of 8.5 seconds / FC # 4 and a coating amount of 50 g / m ² (wet ) And then heat-treated at 140 ° C. for 4 minutes to form a coating film.

<Undercoating 3>
Acrylic copolymer consisting of methyl methacrylate / 2-ethylhexyl acrylate / methacrylic acid = 64/33/3: 11.5 parts, the above-mentioned Epoxy EA-7: 9 parts, the above-mentioned Epoxy EB-1: 8 parts, titanium White: 10 parts, Calcium carbonate: 28 parts, Dispersant, film-forming aid, thickener, etc .: 6 parts and water: 27.5 parts, a coating viscosity of 9.5 seconds / FC # 4 The coating amount was 100 g / m ² (wet) by airless spraying, followed by heat treatment at 130 ° C. for 210 seconds to form a coating film.

<Undercoating 4>
Acrylic copolymer consisting of methyl methacrylate / butyl acrylate / styrene / acrylic acid = 45/31/22/2: 30 parts, titanium white: 5 parts, dispersant / film-forming aid / thickening agent, etc .: 7 parts Water: 58 parts of paint was applied with a double roll coater at a coating viscosity of 9 seconds / FC # 4 and a coating amount of 60 g / m ² (wet), and then heat-treated at 100 ° C. for 4 minutes. A coating film was formed.

<Intermediate coating 1>
Acrylic copolymer consisting of methyl methacrylate / butyl acrylate / hydroxyethyl methacrylate / methacrylic acid = 80/18/1/1: 15 parts, titanium white: 12 parts, yellow iron oxide: 0.035 part, calcium carbonate: 10 parts , Mica: 7 parts, dispersant / film forming aid / thickening agent, etc .: 8.5 parts and water: 47.5 parts, a coating viscosity of 16 seconds / ZC # 4 and a coating amount of 65 g / m ² (wet) was applied by a double roll coater, and then heat-treated at 130 ° C. for 70 seconds to form a coating film.

<Intermediate coating 2>
Acrylic copolymer consisting of methyl methacrylate / butyl acrylate / 2-ethylhexyl acrylate / acrylic acid = 66.5 / 6.06.0 / 1.5 (hereinafter referred to as acrylic copolymer A): 20 parts Titanium white: 16 parts, red iron oxide: 0.75 parts, yellow iron oxide: 3.0 parts, carbon black: 0.25 parts, barium sulfate: 9 parts, dispersant, film-forming aid, thickener, etc. A coating consisting of 9 parts and water: 42 parts was applied with a two-roll coater so that the coating viscosity was 16 seconds / ZC # 4 and the coating amount was 60 g / m ² (wet), and then 100 ° C. for 100 seconds. A heat treatment was performed to form a coating film.

<Intermediate coating 3>
Acrylic copolymer A: 20 parts, titanium white: 16 parts, red iron oxide: 0.75 parts, yellow iron oxide: 3.0 parts, carbon black: 0.25 parts, barium sulfate: 9 parts, dispersed By airless spraying, a coating composition consisting of 9 parts and water: 42 parts of coating agent, film forming aid, thickener, etc. is applied at a coating viscosity of 18 seconds / FC # 4 and a coating amount of 80 g / m ² (wet). After coating, a heat treatment was performed at 100 ° C. for 120 seconds to form a coating film.

<Intermediate coating 4>
Acrylic copolymer A: 20 parts, titanium white: 16 parts, red iron oxide: 0.75 parts, yellow iron oxide: 3.0 parts, carbon black: 0.25 parts, barium sulfate: 9 parts, dispersed A coating material consisting of 9 parts and water: 42 parts by airless spray with a coating viscosity of 16 seconds / FC # 4 and a coating weight of 80 g / m ² (wet). After coating, a heat treatment was performed at 100 ° C. for 120 seconds to form a coating film.

<Intermediate coating 5>
Acrylic copolymer A: 28 parts, Titanium white: 18 parts, Red iron oxide: 0.25 part, Yellow iron oxide: 1 part, Carbon black: 0.05 part, Dispersant / film forming aid / increase A paint consisting of 6.7 parts of a viscous agent and 46 parts of water and 46 parts of water was applied by a double roll coater so that the coating viscosity was 25 seconds / ZC # 4 and the coating amount was 40 g / m ² (wet). In this coating, a drying process was not provided, and a wet-on-wet system with top coating was adopted.

<Pattern 1>
Acrylic copolymer composed of methyl methacrylate / 2-ethylhexyl acrylate / styrene = 56/33/11 (hereinafter referred to as acrylic copolymer B): 4 parts, yellow iron oxide: 13.0 parts, red iron oxide: 7 Part, carbon black 0.4 part, dispersant, film-forming aid, thickener, UV absorber, etc .: 17 parts and water: 58.6 parts, an ink composition having a coating viscosity of 15 seconds / FC # 4 The pattern was formed by gravure offset printing so that the coating amount was 20 g / m ² (wet). In this patterning, a drying process was not provided, and a wet-on-wet system with top coating was adopted.

<Top coat 1>
Acrylic copolymer consisting of methyl methacrylate / butyl acrylate / hydroxyethyl methacrylate / methacrylic acid = 80/18/1/1: 15 parts, titanium white: 12 parts, yellow iron oxide: 0.035 part, calcium carbonate: 10 parts , Mica: 7 parts, dispersant, film-forming aid, thickener, etc .: 8.5 parts, water: 47.5 parts, and Snowtex 40 (Nissan Chemical Industries, Ltd. colloidal silica, silicic acid content 40 -41%, particle size 10-20 nm): 10 parts of the emulsion paint of the present invention (synthetic resin emulsion: colloidal silica = approximately 79:21 on a solid basis) was applied at a coating viscosity of 20 seconds / FC # 4 A surface coat layer was formed by coating with a roll coater so that the amount was 45 g / m ² (wet), and then heat-treating at 130 ° C. for 70 seconds in a jet furnace.

<Top coat 2>
Acrylic copolymer consisting of methyl methacrylate / butyl acrylate / hydroxyethyl methacrylate / methacrylic acid = 80/18/1/1: 15 parts, titanium white: 12 parts, yellow iron oxide: 0.035 part, calcium carbonate: 10 parts , Mica: 7 parts, dispersant / film-forming aid / thickener, etc .: 8.5 parts, water: 47.5 parts and the above-mentioned SNOWTEX 40:10 parts of the emulsion paint of the present invention (based on solid content) And a synthetic resin emulsion: colloidal silica = approx. 79:21) is applied by a two-roll coater so that the coating viscosity is 12 seconds / FC # 4 and the coating amount is 55 g / m ² (wet). The film was heated at 110 ° C. for 100 seconds to form a surface coating layer.

<Top coat 3>
Acrylic copolymer A: 28 parts, Titanium white: 18 parts, Red iron oxide: 0.25 part, Yellow iron oxide: 1 part, Carbon black: 0.05 part, Dispersant / film forming aid / increase An emulsion paint of the present invention (synthetic resin emulsion: colloidal silica = about 82:18 based on solid content) comprising 6.7 parts of a sticking agent, etc., water: 46 parts and the above-mentioned Snowtex 40:15 parts, and a coating viscosity of 18 The coating was applied with a flow coater so that the coating amount was 70 g / m ² (wet) per second / FC # 4, and then heat-treated at 120 ° C. for 120 seconds in a jet furnace to form a surface coating layer.

<Top coating 4>
Acrylic copolymer B: 22 parts, Udouble E-670 (HAC-containing highly weatherable acrylic emulsion manufactured by Nippon Shokubai Co., Ltd., solid content: 45.5 ± 1.5%, ionicity: anion): 21 parts, Matting agent (silicic anhydride) 1.5 parts, UV absorber, film-forming aid, thickener, etc .: 8 parts, water: 47.5 parts and colloidal silica-treated product: 30 parts of emulsion paint of the present invention (Synthetic resin emulsion: colloidal silica = 86: 14 on a solid basis) was applied by airless spraying so that the coating viscosity was 15 seconds / FC # 4 and the coating amount was 70 g / m ² (wet), and then hot air A surface coating layer was formed by heat treatment at 120 ° C. for 6 minutes in an oven.

  The colloidal silica-treated product is 4.4 parts water: Primal ASE 60 (Rohm & Haas polyacrylic acid resin emulsion, solid content 28 ± 1%, pH 1.8-4.5): 0.5 parts Silane coupling agent, KBE903 (γ-aminopropyltriethoxysilane manufactured by Shin-Etsu Chemical Co., Ltd.): 0.1 part of the mixture and neutralized with stirring, and Snowtex N (Nissan Chemical Industry Co., Ltd.) Colloidal silica made, silicic acid content 20 to 21%, particle size 10 to 20 nm): 25 parts added and stirred to be uniform.

<Top coat 5>
Acrylic copolymer B: 14 parts, Polydelex G621 (Asahi Kasei Co., Ltd. acrylic silicone resin emulsion, solid content 41.5 ± 1.0%, ionicity: anion): 47 parts, matting agent (Silic anhydride, transparent plastic beads, etc.): 7 parts, UV absorber, film-forming aid, thickener, etc .: 10.5 parts, water: 21.5 parts and the above colloidal silica treated product: 30 parts An airless spray of the emulsion paint of the present invention (synthetic resin emulsion on the basis of solid content: colloidal silica = about 87:13) with a coating viscosity of 16 seconds / FC # 4 and a coating amount of 80 g / m ² (wet) And then heat-treated at 110 ° C. for 11 minutes in a hot air oven to form a surface coating layer.

<Top coat 6>
Acrylic copolymer consisting of methyl methacrylate / butyl acrylate / hydroxyethyl methacrylate / methacrylic acid = 80/18/1/1: 15 parts, titanium white: 12 parts, yellow iron oxide: 0.035 part, calcium carbonate: 10 parts , Mica: 7 parts, dispersant / film forming aid / thickening agent, etc .: 8.5 parts and water: 47.5 parts paint with a coating viscosity of 20 seconds / FC # 4 and a coating amount of 45 g / m ² (wet) was applied by a roll coater, and then heat-treated at 120 ° C. for 120 seconds in a jet furnace to form a surface coating layer.

<Top coat 7>
Acrylic copolymer A: 28 parts, Titanium white: 18 parts, Red iron oxide: 0.25 part, Yellow iron oxide: 1 part, Carbon black: 0.05 part, Dispersant / film forming aid / increase A paint consisting of 6.7 parts of a sticking agent and 46 parts of water and 46 parts of water was applied by a flow coater so that the coating viscosity was 18 seconds / FC # 4 and the coating amount was 80 g / m ² (wet), and then in a jet furnace The surface coating layer was formed by heat treatment at 120 ° C. for 120 seconds.

<Topcoat 8>
Acrylic copolymer B: 14 parts, Polydelex G621: 47 parts, matting agent (anhydrous silicic acid, transparent plastic beads, etc.): 7 parts, UV absorber, film forming aid, thickener Etc .: 10.5 parts of water and 21.5 parts of water are applied by airless spray so that the coating viscosity is 16 seconds / FC # 4 and the coating amount is 80 g / m ² (wet). A surface coating layer was formed by heat treatment at 110 ° C. for 11 minutes.

  About each inorganic decorative board obtained in Examples 1-5 and Comparative Examples 1-4, the following various characteristics were evaluated by the following method and the following criteria, respectively. The evaluation results were as shown in Table 2.

<Evaluation of blocking properties>
Loading was performed under the loading conditions shown in Table 2, and the state after 20 hours of loading was visually evaluated according to the following evaluation criteria.
○: No change
Δ: There is a minute peeling of the coating film or a slight gloss abnormality in the concentrated load pressure contact part.
×: Clear coating film peeling or gloss abnormal part.

<Evaluation of adhesion>
In accordance with JIS K 5400 8.5.2 Cross-cut tape method, 25 squares are cut with a cutter knife at intervals of 4 mm, cellophane tape is applied and peeled off rapidly, and the remaining number in 25 is counted. .

<Evaluation of hot water resistance>
The test piece was immersed in warm water at 50 ° C. for 5 days, taken out, and allowed to stand for 24 hours. The whitening state of the coating film was visually evaluated according to the following evaluation criteria.
○: No change △: Minor change such as whitening ×: Large change such as whitening

<Evaluation of frost resistance>
The test piece was placed in a freezing cycle tester, the number of cycles shown in Table 2 was repeated according to ASTM C 666 method A, and the appearance of the coating after the test was visually evaluated according to the following evaluation criteria.
○: No change in cracks, etc. Δ: Minor crack generation or partial peeling of coating film ×: Significant cracking, peeling of coating film

<Evaluation of weather resistance>
Using the super accelerated weathering tester “Metal Weather” manufactured by Daipura Wintes Co., Ltd., the contents of one cycle are L → R → Shower → D → Shower, and the number of cycles shown in Table 2 is repeated. The appearance was visually observed and the gloss retention was measured and evaluated according to the following evaluation criteria.
Note that L means irradiation for 16 hours at a wavelength of 295 to 780 nm, light energy of 63 mW / cm ² , temperature of 65 ° C. and humidity of 70%, and R means standing at temperature of 65 ° C. and humidity of 70% for 2 hours without irradiation. The shower means pure water for 10 seconds, and D means that the temperature is 30 ° C. and the humidity is 98% or more, and it is left for 6 hours without irradiation.
○: No change in coating film appearance and gloss retention of 70% or more,
Δ: coating film appearance change is minor, gloss retention 55-69%,
X: The coating film changes significantly or the gloss retention is 54% or less.

Claims (4)

An emulsion paint comprising 95 to 45% by mass of a water-dilutable synthetic resin emulsion as a binder component on a solids basis and 5 to 55% by mass of colloidal silica on a solids basis. The synthetic resin component of the water-dilutable synthetic resin emulsion is a copolymer of α and β unsaturated monomers, and the ionicity is anionic, anionic-nonionic or nonionic. Emulsion paint. The emulsion paint according to claim 1 or 2, wherein the silica component particles of the colloidal silica are granular or pearl-like, and the pH of the colloidal silica is 8.4 to 11.5. In the manufacturing method of the inorganic decorative board which consists of forming a lower layer coating film layer on the surface of an inorganic base material, and forming a surface coating layer on the surface of this lower layer coating layer layer, In any one of Claims 1-3. A method for producing an inorganic decorative board, comprising forming the surface coating layer using an emulsion paint.