JP2007120281A - Wall face structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the beautiful appearance of a decorative coating layer and avoid defects such as cracks, in a wall face structure comprising a plurality of building boards and the decorative coating layer provided thereon. <P>SOLUTION: The decorative coating layer comprises an undercoating film and a topcoating film. The undercoating film is formed of an undercoating containing an epoxy group containing synthetic resin emulsion having a glass transition temperature of -40 to 40°C. The topcoating film is formed of a topcoating including a multi-layer structure type synthetic resin emulsion (A) consisting of an outer layer of a carboxyl group containing acrylic resin having a glass transition temperature of 20 to 100°C and an inner layer including a silicone resin derived from a cyclosiloxane compound and an acrylic resin having a glass transition temperature of -60 to 20°C, a pigment and/or an aggregate (B). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a novel wall surface structure.

  Conventionally, various building boards have been used as building wall materials. In order to give aesthetics to the wall composed of such building boards, it is common to finish the base material on joints between the installed boards and then apply a decorative coating material to finish. Has been adopted. However, in this method, cracks or the like may occur in the decorative coating film due to the displacement of the board due to vibration, temperature change, or the like.

As a technique for improving the above problem, for example, Patent Document 1 describes that a small hole is provided in a butt portion of a gypsum board, and urethane foam resin is injected from the small hole, and then surface decorative coating is performed. . The method of Patent Document 1 utilizes the elasticity of a foamed urethane resin in order to suppress the occurrence of cracks at joints. However, the ground treatment process becomes complicated and is not very practical in terms of work efficiency.
On the other hand, by devising the composition of the decorative coating material, there is a movement to impart a crack suppressing effect to the decorative coating material itself and simplify the ground treatment (Patent Document 2 and the like). For example, the decorative coating material described in Patent Document 2 is mainly composed of a synthetic resin emulsion, an inorganic filler, carbon fiber, and synthetic fiber, and aimed at a crack suppression effect due to the combined action of carbon fiber and synthetic fiber. Is. However, in the cosmetic coating material of Patent Document 2, since black carbon fiber is included as an essential component, there is room for improvement in terms of aesthetics.

JP-A-2-66252 JP 2001-288869 A

  The present invention has been made in view of the above-described problems, and is composed of a plurality of building boards, and in a wall structure having a decorative coating layer provided on the surface thereof, the aesthetics of the decorative coating layer are improved. The purpose is to suppress the occurrence of defects such as cracks while increasing.

  As a result of intensive studies to achieve the above object, the present inventor has conceived that a decorative coating layer having a specific undercoat coating film and a top coating film is provided, and the present invention is completed. It was.

That is, the present invention has the following characteristics.
1. In a wall structure composed of a plurality of building boards and provided with a decorative coating layer straddling the joints of the building boards, the decorative coating layer has a primer coating film and a top coating film. And
The primer coating film is formed by a primer comprising an epoxy group-containing synthetic resin emulsion having a glass transition temperature of −40 to 40 ° C.,
The top coating film is a carboxyl group-containing acrylic resin with an outer layer having a glass transition temperature of 20 to 100 ° C., and an inner layer contains a silicone resin derived from a cyclic siloxane compound and an acrylic resin with a glass transition temperature of −60 to 20 ° C. A wall surface structure characterized by being formed by a top coating material containing a multilayer structure type synthetic resin emulsion (A), a pigment and / or an aggregate (B).
2. The top coating material contains a crosslinking agent (C) having a functional group capable of reacting with a carboxyl group in addition to the component (A) and the component (B). Wall surface structure as described.

  In the wall surface structure of the present invention, the occurrence of cracks at joints and the like can be effectively suppressed. Furthermore, in the wall surface structure of the present invention, excellent aesthetics can be expressed, and the aesthetics can be maintained for a long time.

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

The wall surface structure of the present invention is composed of a plurality of building boards, and a decorative coating layer is provided across the joints of the building boards.
Examples of building boards include cement boards, extruded boards, slate boards, PC boards, ALC boards, fiber reinforced cement boards, metal siding boards, ceramic siding boards, ceramic boards, calcium silicate boards, plaster boards, plastics Examples include boards, hard wood cement boards, PVC extrusion siding boards, and plywood.

  A joint is formed between the building boards provided. This joint is filled with a sealing material and / or a putty material as necessary. Prior to filling the sealing material and / or putty material, a backup material filling or primer coating may be performed in advance. As the backup material, for example, a foamed polyethylene-based backup material or the like can be used. As the primer, for example, a synthetic rubber primer, an acrylic primer, a urethane primer, an epoxy primer, a silicone resin primer, a silane primer, or the like can be used.

The sealing material and / or putty material may be appropriately selected and used according to the shape of the end of the building board, the width and depth of the joint part to be formed, etc., and only one of them may be used However, both may be used in combination.
General sealants can be used, such as silicone sealants, modified silicone sealants, polysulfide sealants, modified polysulfide sealants, acrylic urethane sealants, polyurethane sealants, SBR. And the like, and butyl rubber sealing material. The filling method of the sealing material is not particularly limited, and for example, a known method using a gun or a spatula can be employed.

  Examples of putty materials include silicone-based putty materials, modified silicone-based putty materials, polysulfide-based putty materials, modified polysulfide-based putty materials, acrylic urethane-based putty materials, polyurethane-based putty materials, acrylic-based putty materials, SBR-based putty materials, Examples include butyl rubber-based putty materials. A spatula or the like may be used for filling the putty material. After filling the putty material, the surface can be polished.

  In the present invention, when the putty material is filled, a net-like body can be interposed in or on the putty material. By using such a net-like body, the tensile strength of the joint can be improved and the follow-up performance of the decorative coating film can be enhanced. As the network, a fibrous network made of various natural fibers and synthetic fibers is suitable.

  The decorative coating layer in the present invention has a primer coating film and a top coating film. Among these, the primer coating film is formed by a primer containing an epoxy group-containing synthetic resin emulsion. This primer coating film ensures the adhesion of the decorative coating layer to the base, improves the effect of preventing peeling and swelling over time, the surface condition of the base, and improves the finish of the top coating film Has effects and the like.

As the epoxy group-containing resin in the epoxy group-containing synthetic resin emulsion, an epoxy group-containing acrylic resin is suitable. As the epoxy group-containing acrylic resin, for example, an epoxy group-containing monomer such as glycidyl (meth) acrylate, (meth) acrylate methyl ester, and, if necessary, other monomers polymerized by a conventional method can be used. The glass transition temperature (hereinafter referred to as “Tg”) of the epoxy group-containing acrylic resin is −40 to 40 ° C., preferably −30 to 30 ° C. If the Tg of the epoxy group-containing acrylic resin is within such a range, sufficient physical properties can be secured in terms of adhesion and crack prevention. Note that Tg in the present invention is a value obtained by the Fox calculation formula.
The undercoat material may contain a synthetic resin emulsion other than the epoxy group-containing synthetic resin emulsion, a water-soluble resin, and the like. Moreover, a coloring pigment, an extender, etc. may be contained.

  The primer coating film can be formed by coating the primer with a known method. As a coating method, for example, spray coating, roller coating, brush coating, and the like are possible. The thickness of the primer coating film depends on the form of the primer, but in the case of a thin film type such as a sealer, it is about 0.01 to 0.2 mm, and in the case of a thick film type such as a surfacer, it is about 0.2 to 2 mm. is there. When a thick film type such as a surfacer is used as an undercoat material, a surface pattern such as a yuzu skin shape, a spray tile shape, or a ripple shape can be formed.

  Such a primer coating film may have elasticity. As an undercoat material having elasticity, a material having an elongation rate of 120% or more (preferably 120% to 800%) of the formed coating film according to JIS A6909 “elongation test at 20 ° C.” is used. it can.

  The top coating film in the decorative coating layer is formed by a multi-layer structure type synthetic resin emulsion (A) and a top coating material containing a pigment and / or an aggregate (B). Among them, the multilayer structure type synthetic resin emulsion (A) (hereinafter referred to as “component (A)”) is a silicone resin derived from a cyclic siloxane compound in the inner layer, which is a carboxyl group-containing acrylic resin having a Tg of 20 to 100 ° C. And an acrylic resin having a Tg of 60 to 20 ° C. In the present invention, by using such a component (A) in the top coating material, the followability to the base is increased, and a coating film having excellent crack prevention properties can be formed. Furthermore, since the anti-contamination performance can be enhanced, it is advantageous in that the initial aesthetics can be maintained. The weight ratio of the outer layer to the inner layer in the component (A) is usually 80:20 to 20:80, preferably 70:30 to 30:70.

  In order to generate a carboxyl group in the outer layer of the component (A), a carboxyl group-containing monomer may be used as a monomer constituting the outer layer. Examples of the carboxyl group-containing monomer include acrylic acid, methacrylic acid, crotonic acid, maleic acid or a monoalkyl ester thereof, itaconic acid or a monoalkyl ester thereof, fumaric acid or a monoalkyl ester thereof. Among these, at least one selected from acrylic acid and methacrylic acid is particularly preferable. The usage-amount of a carboxyl group-containing monomer is 0.1 to 40 weight% normally with respect to the resin solid content of (A) component, Preferably it is 0.5 to 20 weight%. Such a carboxyl group contributes to improvement in adhesion.

  The outer layer of the component (A) is a copolymer of the above carboxyl group-containing monomer, (meth) acrylic acid ester, and other monomers as required. Examples of (meth) acrylic acid esters include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, n-amyl (meth) acrylate, isoamyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, octadecyl ( Examples include meth) acrylate, cyclohexyl (meth) acrylate, phenyl (meth) acrylate, and benzyl (meth) acrylate. Examples of other monomers include amino group-containing monomers, pyridine monomers, hydroxyl group-containing monomers, nitrile group-containing monomers, amide group-containing monomers, epoxy group-containing monomers, carbonyl group-containing monomers, alkoxysilyl group-containing monomers, aromatic monomers, etc. Is mentioned. Among these, if t-butyl (meth) acrylate is used as the (meth) acrylic acid ester, the adhesion is enhanced, and the occurrence of swelling and peeling of the coating film can be prevented, which is advantageous in terms of maintaining aesthetics.

  (A) Tg of the outer layer of a component is 20-100 degreeC normally, Preferably it is 30-90 degreeC. When the Tg of the outer layer is too lower than such a range, sufficient physical properties cannot be obtained in terms of stain resistance. Conversely, when the Tg is too high, the followability to the ground is lowered.

  The inner layer of the component (A) includes a silicone resin derived from a cyclic siloxane compound and an acrylic resin having a Tg of 60 to 20 ° C. In the present invention, since the inner layer of the component (A) is composed of such two types of specific resins, it is possible to exhibit excellent performance in the followability to the ground without lowering the stain resistance. . When the inner layer of the component (A) is composed of only one of these resins, it becomes difficult to achieve both contamination resistance and followability to the ground. The weight ratio of the silicone resin and the acrylic resin in the inner layer is usually 70:30 to 1:99, preferably 60:40 to 3:97.

  Among these, the silicone resin is obtained by polymerizing a cyclic siloxane compound. Examples of the cyclic siloxane compound include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and the like. When polymerizing such a cyclic siloxane compound, a linear siloxane compound, a branched siloxane compound, an alkoxysilane compound, or the like can also be used. Of these, as the alkoxysilane compound, a silane compound having one or more alkoxyl groups in the molecule can be used. For example, tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, vinylmethyldimethoxysilane, γ- Silane coupling agents such as (meth) acryloyloxytrimethoxysilane and 3-mercaptopropyltrimethoxysilane can be used. The average molecular weight of the silicone resin is usually 10,000 or more, preferably 50,000 or more.

  (A) Tg of the acrylic resin which comprises the inner layer of a component is set to -60-20 degreeC (preferably -50-10 degreeC). When the Tg is too low, the stain resistance is insufficient, and when it is too high, the followability to the ground is lowered. The acrylic resin constituting the inner layer of the component (A) can be obtained by copolymerizing (meth) acrylic acid ester and other monomers as necessary so that Tg is in such a range.

  The form of these two kinds of resins in the inner layer of the component (A) is not particularly limited, and may be a form in which the two are uniformly mixed with each other. The form in which the silicone resin is inside and the acrylic resin is outside, the acrylic resin May be a form in which the internal / silicone resin is present outside, a form in which the silicone resin is dispersed in the acrylic resin, a form in which the acrylic resin is dispersed in the silicone resin, and the like.

  (A) Although the manufacturing method of a component is not specifically limited, For example, after carrying out the emulsion polymerization of the acrylic resin which comprises an inner layer in presence of the aqueous dispersion of a silicone resin, the method of carrying out the emulsion polymerization of the acrylic resin which comprises an outer layer, etc. Can be adopted.

  The pigment and / or aggregate (B) (hereinafter referred to as “component (B)”) in the top coating material is a component that imparts aesthetics to the top coating film. In the present invention, by adjusting the type and mixing ratio of the component (B), a desired color / uneven pattern or the like can be imparted.

  Among these, examples of the pigment include titanium oxide, zinc oxide, carbon black, lamp black, bone black, graphite, black iron oxide, copper chrome black, cobalt black, copper manganese iron black, bengara, molybdate orange, permanent red. , Permanent carmine, anthraquinone red, perylene red, quinacridone red, yellow iron oxide, titanium yellow, first yellow, benzimidazolone yellow, chrome green, cobalt green, phthalocyanine green, ultramarine, bitumen, cobalt blue, phthalocyanine blue, quinacridone violet, Dioxazine violet, heavy calcium carbonate, precipitated calcium carbonate, kaolin, talc, clay, clay, china clay, barium sulfate, barium carbonate, Stone powder, diatomaceous earth, aluminum pigments, pearl pigments and the like. The particle diameter of these pigments is usually less than 50 μm (preferably 40 μm or less). The pigment ratio in the top coating material is usually 5 to 500 parts by weight (preferably 10 to 400 parts by weight) with respect to 100 parts by weight of the solid content of the component (A).

  In the top coating material of the present invention, an elastic-type matte paint can be obtained by setting the pigment ratio high within the above range. In such a case, the pigment ratio may be set to about 100 to 500 parts by weight (preferably 150 to 400 parts by weight) with respect to 100 parts by weight of the solid content of the component (A).

The “matte” referred to here includes not only what is generally called matte but also what is called three-minute gloss, five-minute gloss, and the like. Specifically, in the present invention, the gloss can be defined by the specular gloss. The specular gloss in the matte paint described above is usually 40 or less, preferably 20 or less, and more preferably 10 or less. The gloss of the matte paint can be adjusted as appropriate depending on the type, particle diameter, mixing ratio, etc. of the extender pigment to be blended in the matte paint.
Here, the specular glossiness is a value measured according to JIS K5600-4-7 “Specular glossiness”. Specifically, paint gloss is applied to one side of a glass plate using a film applicator with a clearance of 150 μm, the specular gloss when the coated surface is horizontally placed and dried at a temperature of 23 ° C. and a relative humidity of 50% for 48 hours. This is a value obtained by measuring (measuring angle 60 degrees).

  In such a matte paint, the pigment having an oil absorption of 60 ml / 100 g or less (preferably 50 ml / 100 g or less) is 50 volume% or more (preferably 60 volume% or more, more preferably 70 volume% or more) of the whole pigment component. It is desirable to prepare so that it may become. Such preparation makes it possible to ensure sufficient followability to the ground. The oil absorption amount (ml / 100 g) is a value obtained by the method defined in JIS K 5101-13-2: 2004, and is expressed in ml of boiled linseed oil with respect to 100 g of the granular material. is there.

  On the other hand, as the aggregate, at least one selected from natural aggregates such as natural stones, pulverized natural stones, and artificial aggregates such as colored aggregates can be suitably used. Specifically, for example, marble, granite, serpentinite, granite, fluorite, cryolite, feldspar, limestone, quartzite, quartz sand, crushed stone, mica, siliceous shale, and pulverized products thereof, ceramic pulverized product, ceramic pulverized product Products, glass pulverized products, glass beads, glass flakes, resin pulverized products, resin beads, rubber grains, shell pieces, plastic pieces and the like. Those obtained by coloring them can also be used. The particle diameter of the aggregate is usually about 0.05 to 5 mm. The aggregate ratio in the top coating material is usually 10 to 1000 parts by weight (preferably 50 to 500 parts by weight) with respect to 100 parts by weight of the solid content of the component (A). The total ratio of the pigment and the aggregate may be about 5 to 1000 parts by weight (preferably 10 to 500 parts by weight) with respect to 100 parts by weight of the solid content of the component (A).

  In addition to the above-described components, the top coating material preferably contains a crosslinking agent (C) having a functional group capable of reacting with a carboxyl group (hereinafter referred to as “component (C)”). In this invention, generation | occurrence | production of the swelling of a coating film, peeling, etc. can be prevented more reliably by using such (C) component. Furthermore, the tackiness of the coating film surface is reduced and the stain resistance is increased.

Examples of the functional group capable of reacting with a carboxyl group in the component (C) include a carbodiimide group, an epoxy group, an aziridine group, and an oxazoline group. These can be used alone or in combination of two or more. Among these, an epoxy group is particularly preferable in the present invention.
Examples of the reactive compound having an epoxy group include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, glycerol polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol poly Examples thereof include glycidyl ether, diglycerol polyglycidyl ether, polyhydroxyalkane polyglycidyl ether, and sorbitol polyglycidyl ether. In addition, water-soluble resins and emulsions composed of polymers (homopolymers or copolymers) of epoxy group-containing monomers can also be mentioned. These can be used alone or in combination of two or more.

  The proportion of component (C) depends on the degree of reactivity of component (C) used, but is usually 0.1 to 50 parts by weight (preferably 0 to 100 parts by weight of resin solids of component (A)). .3 to 20 parts by weight, more preferably 0.5 to 10 parts by weight)

  In the top coating material, in addition to the above-mentioned components, components that can be used in ordinary paints can also be included. Examples of such components include fibers, thickeners, film-forming aids, leveling agents, wetting agents, plasticizers, antifreezing agents, pH adjusting agents, antiseptics, antifungal agents, algaeproofing agents, and antibacterial agents. , Dispersants, antifoaming agents, adsorbents, crosslinking agents, ultraviolet absorbers, antioxidants, catalysts and the like. The top coating material can be produced by uniformly mixing the above components by a conventional method.

  The top coat film can be formed by coating the above coat material on the under coat film by a known method. The coating method can be appropriately selected depending on the type of the top coating material. For example, trowel coating, spray coating, roller coating, brush coating, or the like can be employed. The thickness of the top coating film is not particularly limited and can be appropriately set. When the component (B) is composed of only a pigment, about 0.02 to 2 mm, and the aggregate is included as the component (B). In the case, it is about 0.5 to 10 mm.

  If necessary, a clear layer can be provided on the decorative coating layer. Such a clear layer can be formed by, for example, a clear paint using an acrylic resin, a urethane resin, an acrylic silicon resin, a fluorine resin, or the like as a binder. The gloss level of such a clear layer can be adjusted with a known matting agent or the like. Moreover, as long as the effect of this invention is not inhibited, coloring can also be given.

  FIG. 1 shows an example (cross-sectional view) of the wall surface structure of the present invention. In FIG. 1, putty material 2 is filled in joint portions of two side-by-side building boards 1, and a decorative coating layer 3 is provided thereon. The decorative coating layer 3 is formed by laminating a primer coating film 4 and a top coating film 5. In addition, the wall surface structure of this invention is not limited to the aspect shown in FIG. 1, A certain layer (a surface treatment layer, an old coating film layer, etc.) exists between the building board 1 and the decorative coating layer 3. It may be interposed.

  Examples are given below to clarify the features of the present invention.

(Manufacture of top coating materials)
According to the formulation shown in Table 1, the top coating material was manufactured by mixing and stirring each raw material by a conventional method. The following were used as raw materials.

Resin 1: Multi-layer structure type synthetic resin emulsion outer layer; acrylic resin (Tg 45 ° C., component: t-butyl methacrylate, n-butyl methacrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methacrylic acid),
Inner layer: silicone resin (components: hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane), acrylic resin (Tg-50 ° C, components: n-butyl methacrylate, n-butyl acrylate, 2- Ethylhexyl acrylate), weight ratio of silicone resin to inner layer acrylic resin 18:82,
Weight ratio of outer layer to inner layer 45:55, solid content 50% by weight, carboxyl group-containing monomer 3% by weight (in solid content)

Resin 2: Multi-layer structure type synthetic resin emulsion outer layer; acrylic resin (Tg 45 ° C., component: methyl methacrylate, n-butyl methacrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methacrylic acid),
Inner layer: silicone resin (components: hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane), acrylic resin (Tg-50 ° C, components: n-butyl methacrylate, n-butyl acrylate, 2- Ethylhexyl acrylate), weight ratio of silicone resin to inner layer acrylic resin 18:82,
Weight ratio of outer layer to inner layer 45:55, solid content 50% by weight, carboxyl group-containing monomer 3% by weight (in solid content)

Resin 3: Multi-layer structure type synthetic resin emulsion outer layer; acrylic resin (Tg 45 ° C., component: t-butyl methacrylate, n-butyl methacrylate, n-butyl acrylate, 2-ethylhexyl acrylate, diacetone acrylamide, methacrylic acid),
Inner layer: silicone resin (components: hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane), acrylic resin (Tg-50 ° C, components: n-butyl methacrylate, n-butyl acrylate, 2- Ethylhexyl acrylate), weight ratio of silicone resin to inner layer acrylic resin 18:82,
Weight ratio of outer layer to inner layer 45:55, solid content 50% by weight, carboxyl group-containing monomer 3% by weight (in solid content)

Resin 4: Multi-layer structure type synthetic resin emulsion outer layer; acrylic resin (Tg 45 ° C., component: t-butyl methacrylate, n-butyl methacrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methacrylic acid),
Inner layer: acrylic resin (Tg-50 ° C., constituent components: n-butyl methacrylate, n-butyl acrylate, 2-ethylhexyl acrylate),
Weight ratio of outer layer to inner layer 50:50, solid content 50% by weight, carboxyl group-containing monomer 3% by weight (in solid content)

Resin 5: multilayer structure type synthetic resin emulsion outer layer; acrylic resin (Tg 45 ° C., component: t-butyl methacrylate, n-butyl methacrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methacrylic acid),
Inner layer: silicone resin (component: hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane),
Weight ratio of outer layer to inner layer 50:50, solid content 50% by weight, carboxyl group-containing monomer 3% by weight (in solid content)

Resin 6: Acrylic resin emulsion (Tg 12 ° C., component: t-butyl methacrylate, n-butyl methacrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methacrylic acid, solid content 50% by weight, carboxyl group-containing monomer 3% by weight (In solid content)

・ Crosslinking agent 1: Epoxy group-containing compound (polyhydroxyalkane polyglycidyl ether)
Crosslinking agent 2: hydrazine compound (adipic acid dihydrazide)
Pigment 1: White pigment (titanium oxide, average particle size 0.2 μm, specific gravity 4.2, oil absorption 13 ml / 100 g)
Pigment 2: yellow pigment (yellow iron oxide, average particle size 0.8 μm, specific gravity 4.4, oil absorption 35 ml / 100 g)
Pigment 3: extender pigment (heavy calcium carbonate, average particle size 5 μm, specific gravity 2.7, oil absorption 15 ml / 100 g)
Pigment 4: extender pigment (silica powder, average particle size 18 μm, specific gravity 2.7, oil absorption 10 ml / 100 g)
Pigment 5: extender pigment (diatomaceous earth, average particle size 9 μm, specific gravity 2.3, oil absorption 170 ml / 100 g)
Aggregate: colored aggregate mixture having a particle diameter of 0.1 to 2 mm (white: grey: black = 3: 3: 1)
・ Film-forming auxiliary: 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate ・ Dispersant: polycarboxylic acid-based dispersant (solid content 30% by weight)
・ Thickener: Polyurethane thickener (solid content 30% by weight)
-Antifoaming agent: Silicon-based antifoaming agent (solid content 50% by weight)

(Test specimen production)
Two slate plates of 300 x 150 x 6 mm were butted together, and the acrylic putty material was filled in the gap between the butted parts and dried for 24 hours in the standard state (temperature 23 degrees, relative humidity 50%). An epoxy-based primer having an epoxy group-containing acrylic resin emulsion (Tg 20 ° C.) as a binder was spray-coated so that the coating thickness was 0.02 mm. After drying for 3 hours in the standard state, each top coating material was spray-coated so that the thickness of the coating film was 0.1 mm (the top coating material 3 was 1.0 mm), and the test sample was cured for 14 days in the standard state.

(Heating / cooling repeated test)
About the produced test body, after carrying out a total of 10 cycles of hot and cold repeated tests in which water immersion (23 ° C.) 18 hours → −20 ° C. 3 hours → 80 ° C. 3 hours is 1 cycle, occurrence of abnormalities on the surface of the decorative coating ( The presence or absence of cracks, blisters, and peeling) was confirmed visually. Evaluation is “◎” when no abnormality occurred, “○” when almost no abnormality occurred, “△” when abnormality occurred partially, and “ ×

(Contamination resistance test)
The prepared test body was placed horizontally, the dirt component (black cinnabar sand) was sprayed on the surface of the coating film and allowed to stand for 2 hours, and then the test plate was set up vertically, and the degree of the dirt component remaining was confirmed. The evaluation was performed in a four-step evaluation (excellent: ◎>◯>Δ> ×: inferior) where “と す る” indicates that the dirt was removed and “×” indicates that the dirt remained significantly.

(Test results)
The test results are shown in Table 2. In Examples 1-8, good results could be obtained in any test. Among these, Examples 2 to 4 and 6 were particularly excellent.

It is sectional drawing which shows an example of this invention wall surface structure.

Explanation of symbols

1: Building board 2: Putty material 3: Makeup coating film layer 4: Undercoat material coating film 5: Topcoat coating film

Claims (2)

In a wall structure composed of a plurality of building boards and provided with a decorative coating layer straddling the joints of the building boards, the decorative coating layer has a primer coating film and a top coating film. And
The primer coating film is formed by a primer comprising an epoxy group-containing synthetic resin emulsion having a glass transition temperature of −40 to 40 ° C.,
The top coating film is a carboxyl group-containing acrylic resin with an outer layer having a glass transition temperature of 20 to 100 ° C., and an inner layer contains a silicone resin derived from a cyclic siloxane compound and an acrylic resin with a glass transition temperature of −60 to 20 ° C. A wall surface structure characterized by being formed by a top coating material containing a multilayer structure type synthetic resin emulsion (A), a pigment and / or an aggregate (B).   The wall structure according to claim 1, wherein the top coating material contains a crosslinking agent (C) having a functional group capable of reacting with a carboxyl group in addition to the component (A) and the component (B).

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