JP7618074B2 - How to apply makeup - Google Patents

Description

The present invention relates to a decorative method that can be applied to buildings, etc.

Traditionally, concrete, mortar, and various plate-shaped wall materials have been used for the walls of buildings and the like. For example, plate-shaped wall materials that have been given a three-dimensional appearance by providing a concave-convex pattern on their surface and that are coated for protection and beauty are often used. Materials that are used for such coatings are those that can form highly durable coatings such as inorganic coatings, organic-inorganic composite coatings, and fluororesin coatings, from the viewpoints of extending life and reducing maintenance.

Walls constructed from such plate-like wall materials are exposed to the outdoors for long periods of time, and as a result, the surface of the plate-like wall material deteriorates due to the effects of sunlight, rainfall, temperature changes, dust, etc., and the initial aesthetic appeal of the plate-like wall material declines over time. Even for walls that are coated with a highly durable coating, it is difficult to avoid deterioration and loss of aesthetic appeal over time.

JP 2016-117795 A describes applying an undercoat paint containing an epoxy resin, an amine compound, a silane coupling agent, etc. to a coating such as an acrylic silicone resin. The patent publication indicates that such an undercoat paint exhibits good adhesion to a highly durable coating such as an acrylic silicone resin.

JP 2016-117795 A

However, even if the method described in the above patent document is used to apply cosmetic finish to deteriorated surfaces such as plate-like wall materials with uneven patterns, there is a risk of swelling and peeling over time, making it difficult to obtain practically satisfactory results.

The present invention has been made in consideration of the above-mentioned problems, and aims to provide a decorative method that can form a beautiful new coating on an existing wall surface that has an uneven pattern and is equipped with a highly durable existing coating, and that can maintain the finished state for a long period of time.

As a result of extensive research into achieving the above-mentioned objective, the inventor came up with the idea of a method of applying a specific undercoat material and a topcoat material in that order to an existing wall surface as described above, and thus completed the present invention.

That is, the present invention has the following features.
1. A decorative method for existing walls that have deteriorated over time,
The existing wall surface has an uneven pattern on its surface.
The present invention provides a method for manufacturing a steel sheet having an existing coating film, the method comprising the steps of: providing an existing coating film of at least one type selected from an inorganic coating film, an organic-inorganic composite coating film, and a fluororesin coating film;
For the above existing wall,
The composition comprises a resin component, and a powder (m) having an average particle diameter of 1 μm or less and/or a powder (n) having an oil absorption of 100 ml/100 g or more and an average particle diameter of 2 to 100 μm,
the resin component includes a compound having a reactive silyl group, the compound having a reactive silyl group being one or more selected from a tetraalkoxysilane compound, an alkylalkoxysilane compound, and a silane coupling agent;
The powder (n) is one or more selected from zeolite, sodium sulfate, alumina, allophane, diatomaceous earth, hydrous silicon dioxide, vermiculite, perlite, Oya stone powder, activated clay, charcoal, activated carbon, wood powder, and shirasu balloon;
The total amount of the powder (m) and the powder (n) is 10 to 250 parts by weight per 100 parts by weight of the solid content of the resin component, and a pigment volume concentration of 1 to 30% is applied as a base coat material, and after the coating is dried, a top coat material is applied. This is a cosmetic method characterized by the above.
The oil absorption amount is a value measured by the method of JIS K5101-13-1:2004 "Refined linseed oil method".
2. The decorative method according to 1., wherein the existing wall surface is composed of a plurality of plate-shaped wall materials having an uneven pattern on the surface and an existing coating.

According to the present invention, a beautiful new coating can be formed on an existing wall surface that has an uneven pattern and an existing coating, and the finished state can be maintained for a long period of time.

The following describes how to implement the present invention.

The present invention can be applied to existing wall surfaces of buildings, civil engineering structures, etc. Such existing wall surfaces are composed of at least a substrate and an existing coating. Substrates include, for example, concrete, mortar, metal, wood, glass, etc., or various plate-shaped wall materials. Among these, plate-shaped wall materials include, for example, inorganic hardened bodies mainly composed of cement, calcium silicate, lime, gypsum, etc. Specific examples of such plate-shaped wall materials include, for example, cement boards, extrusion molding boards, slate boards, PC boards, ALC boards, fiber-reinforced cement boards, siding boards, ceramic boards, calcium silicate boards, gypsum boards, hard wood chip cement boards, etc.

In the present invention, the existing wall surface is one having a concave-convex pattern on its surface. Various concave-convex patterns on existing wall surfaces can be used, such as tile patterns, brick patterns, geometric patterns, stripes, lattice patterns, polka dot patterns, sand wall patterns, citron skin patterns, ripple patterns, and other patterns that are designed to represent animals and plants. Specifically, the shape of the convex parts when the concave-convex pattern is viewed from the front can be, for example, a square, a rectangle, a circle, an oval, a triangle, a diamond, a polygon, or an indefinite shape. In addition, the cross-sectional shape of the convex parts in the concave-convex pattern can be, for example, a trapezoid, a square, a rectangle, a semicircle, a wave shape, a step shape, a triangle, a mountain shape, and other shapes. Examples of the concave parts in the concave-convex pattern include flat parts that form joints. The height difference between the concave parts and the convex parts can be constant or different in each area, but is preferably 20 mm or less, and more preferably about 1 to 15 mm. Such a concave-convex pattern may be applied to either one or both of the substrate and the existing coating.

In the present invention, the existing wall surface has at least one existing coating (hereinafter also referred to as "highly durable existing coating") selected from an inorganic coating, an organic-inorganic composite coating, and a fluororesin coating on the surface of the substrate. This existing coating is a highly durable coating that has already been applied to the substrate by on-site painting or factory painting (line painting). Examples of such existing coatings include colored coatings (enamel coatings, printed coatings, etc.), clear coatings, and laminated coatings of these, which are coatings formed by applying and curing various coating materials to the substrate. Such coating materials may be, for example, any of room temperature drying type, room temperature curing type, bake curing type, ultraviolet (UV) curing type, and electron beam curing type.

Examples of binders for such coating materials include inorganic binders such as silicone resin, alkoxysilane, colloidal silica, and silicate, organic-inorganic composite binders such as acrylic silicone resin, and fluororesins.

The present invention is particularly suitable when the existing coating on the outermost surface is one or more selected from inorganic coatings (coatings containing the above-mentioned inorganic binder), organic-inorganic composite coatings (coatings containing the above-mentioned organic-inorganic composite binder), fluororesin coatings (coatings containing the above-mentioned fluororesin), etc., and can also be suitably applied to these clear coatings. Such existing coatings may contain photocatalytic titanium oxide, etc.

The present invention can be applied as a renovation method for existing wall surfaces as described above that have deteriorated over time. The degree of deterioration is not particularly limited, but any wall surface that has been used for approximately five years or more (even eight years or more) can be subject to the present invention.

The existing wall surface of the present invention is preferably constructed by arranging multiple plate-shaped wall materials that have a textured pattern on their surface and a highly durable existing coating. The present invention can achieve advantageous effects when used on an existing wall surface that is constructed from multiple plate-shaped wall materials. It is desirable for the textured pattern to be applied to at least the plate-shaped wall materials themselves. The joints between the plate-shaped wall materials may be filled with a sealant or dry joint material.

The decorative method of the present invention involves applying (painting) a base coat and a top coat in that order to an existing wall surface that has deteriorated over time as described above.

In the present invention, a primer containing a resin component and a powder (m) having an average particle size of 1 μm or less and/or a powder (n) having an oil absorption of 100 ml/100 g or more in a specific ratio is used. In the present invention, the use of such a primer makes it possible to maintain the finish state of the new coating formed on the above-mentioned existing wall surface for a long period of time.

The resin component in the undercoat material can be, for example, a water-based resin such as a water-soluble resin or a water-dispersible resin, a non-aqueous resin such as a solvent-soluble resin or a non-water-dispersible resin, or a solventless resin.

When an aqueous resin is used as the resin component, an aqueous primer can be obtained. The aqueous primer contains water as a medium, and may further contain a water-soluble solvent such as a lower alcohol, a polyhydric alcohol, an ether compound, an ester compound, or an alkylene oxide-containing compound, as necessary.

When a non-aqueous resin is used as the resin component, a non-aqueous primer can be obtained. A non-aqueous primer contains a non-aqueous solvent as a medium. Examples of non-aqueous solvents include aliphatic hydrocarbon solvents such as n-heptane, n-hexane, n-pentane, n-octane, n-nonane, n-decane, n-undecane, and n-dodecane, alicyclic hydrocarbon solvents such as methylcyclohexane and ethylcyclohexane, aliphatic hydrocarbon-containing mixed solvents such as mineral spirits, petroleum solvents such as petroleum ether, petroleum naphtha, solvent naphtha, and kerosene, as well as isoparaffin-based solvents, alcohol-based solvents, ether alcohol-based solvents, ether-based solvents, ester-based solvents, ether ester-based solvents, and ketone-based solvents. These can be used alone or in combination of two or more.

It is desirable for the non-aqueous undercoat material to contain a non-aqueous solvent with an aniline point of 12 to 70°C. It is believed that such a non-aqueous solvent contributes to improved adhesion by slightly swelling or dissolving the existing coating. Suitable non-aqueous solvents with an aniline point of 12 to 70°C include, for example, one or more selected from aliphatic hydrocarbon-containing mixed solvents such as mineral spirits, and petroleum-based solvents such as petroleum ether, petroleum naphtha, solvent naphtha, and kerosene. The aniline point is a value measured according to the method of JIS K2256.

The resin component in the primer is composed of one or more compounds, and it is desirable that at least one of the compounds is a compound having a reactive silyl group. By including a compound having a reactive silyl group as a constituent of the resin component in the primer, adhesion to existing coatings such as inorganic coatings, organic-inorganic composite coatings, and fluororesin coatings can be further improved, which is preferable in terms of improving the effects of the present invention. The mechanism of action is not limited to the following, but it is thought that the crosslinking reactivity of the reactive silyl group and the affinity to existing coatings, etc., contribute to this.

The reactive silyl group is, for example, an alkoxyl group, a hydroxyl group, a phenoxy group, a mercapto group, an amino group, a halogen, or one or more functional groups bonded to a silicon atom. Among these, an alkoxysilyl group in which an alkoxyl group is bonded to a silicon atom, and/or a silanol group in which a hydroxyl group is bonded to a silicon atom are preferred.

Examples of compounds having a reactive silyl group include tetraalkoxysilane compounds, alkylalkoxysilane compounds, silane coupling agents, reactive silyl group-containing vinyl compounds, and compounds derived from these (e.g., condensates, modified products, polymers, copolymers, etc.). These can be used alone or in combination of two or more.

Among these, examples of tetraalkoxysilane compounds include tetramethoxysilane, tetraethoxysilane, and tetrabutoxysilane.

Examples of alkylalkoxysilane compounds include methyltrimethoxysilane, methyltriethoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltributoxysilane, propyltrimethoxysilane, propyltriethoxysilane, butyltrimethoxysilane, butyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldibutoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, dipropyldimethoxysilane, dipropyldiethoxysilane, dibutyldimethoxysilane, dibutyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, diphenyldibutoxysilane, methylphenyldimethoxysilane, methylphenyldiethoxysilane, etc.

Examples of silane coupling agents include epoxy group-containing silane coupling agents such as γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropylmethyltriethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, amino group-containing silane coupling agents such as N-β(aminoethyl)γ-aminopropylmethyltriethoxysilane, γ-aminopropyltrimethoxysilane, and γ-aminopropyltriethoxysilane, as well as isocyanate group-containing silane coupling agents, isocyanurate group-containing silane coupling agents, and acid anhydride group (carboxyl group)-containing silane coupling agents.

Examples of reactive silyl group-containing vinyl compounds include γ-(meth)acryloxypropyltrimethoxysilane, γ-(meth)acryloxypropyltriethoxysilane, γ-(meth)acryloxypropylmethyldimethoxysilane, and γ-(meth)acryloxypropylmethyldiethoxysilane. Such reactive silyl group-containing vinyl compounds can be used in the form of resins (e.g., acrylic silicone resins, etc.) obtained by copolymerization with other monomers. Examples of such monomers include (meth)acrylic acid alkyl esters, hydroxyl group-containing monomers, carboxyl group-containing monomers, amino group-containing monomers, pyridine-based monomers, nitrile group-containing monomers, amide group-containing monomers, epoxy group-containing monomers, carbonyl group-containing monomers, fluorine-containing monomers, aromatic monomers, ultraviolet absorbing group-containing monomers, and light-stable group-containing monomers. These can be used alone or in combination of two or more. In the present invention, acrylic acid alkyl esters and methacrylic acid alkyl esters are collectively referred to as (meth)acrylic acid alkyl esters. A monomer is a general term for a compound that has a polymerizable unsaturated double bond.

The resin component in the primer can contain compounds other than those having reactive silyl groups. Examples of such compounds include various resins such as acrylic resin, polyester resin, polyether resin, polyurethane resin, fluororesin, vinyl acetate resin, epoxy resin, and polyvinyl chloride resin, as well as various compounds capable of producing these resins.

Examples of the resin components of the primer are shown below as modes (1) to (4).

(1) When a resin containing a reactive silyl group-containing vinyl compound in its resin components is used, for example, a resin obtained by copolymerizing at least a reactive silyl group-containing vinyl compound and a hydroxyl group-containing monomer, such a resin can be used in combination with, for example, a polyisocyanate compound (described later) or the like.

(2) When a resin containing a reactive silyl group-containing vinyl compound in its resin components is used, for example, a resin obtained by copolymerizing at least a reactive silyl group-containing vinyl compound and an epoxy group-containing monomer, such a resin can be used in combination with, for example, a polyamine compound (described later) or the like.

(3) The resin component in the primer may include a polyol compound, a polyisocyanate compound, and a compound having a reactive silyl group.

In this embodiment (3), examples of the polyol compound include polyether polyol, polyester polyol, acrylic polyol, polyisoprene polyol, carbonate polyol, etc., and one or more of these can be used. The hydroxyl value of the polyol compound is preferably 10 to 200 KOHmg/g, more preferably 20 to 100 KOHmg/g. The hydroxyl value is a value expressed by the number of mg of potassium hydroxide equivalent to the moles of hydroxyl groups contained in 1 g of resin solids.

In aspect (3), it is preferable that the polyol compound contains an acrylic polyol (a hydroxyl group-containing acrylic resin). The acrylic polyol can be a polymer of (meth)acrylic acid alkyl ester, a hydroxyl group-containing monomer, and other monomers as necessary, as resin components. The (meth)acrylic acid alkyl ester and the hydroxyl group-containing monomer can be the same as those described above. Examples of the other monomers include carboxyl group-containing monomers, amino group-containing monomers, pyridine monomers, nitrile group-containing monomers, amide group-containing monomers, epoxy group-containing monomers, carbonyl group-containing monomers, alkoxysilyl group-containing monomers, aromatic monomers, ultraviolet absorbing group-containing monomers, and light stable group-containing monomers. These can be used alone or in combination of two or more.

The polyisocyanate compound has two or more isocyanate groups in one molecule, and crosslinks with the polyol compound to form a polyurethane resin coating. Examples of polyisocyanate compounds include toluene diisocyanate (TDI), 4,4-diphenylmethane diisocyanate (pure-MDI), polymeric MDI, xylylene diisocyanate (XDI), hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), hydrogenated XDI, hydrogenated MDI, and derivatives thereof (e.g., compounds obtained by urethane reaction, allophanate reaction, isocyanurate reaction, etc.), and those having allophanate groups, and those having allophanate groups and isocyanurate groups can also be used. These can be used alone or in combination of two or more.

The mixing ratio of the polyisocyanate compound may be set taking into consideration the equivalent ratio of the isocyanate groups of the polyisocyanate compound to the hydroxyl groups of the hydroxyl group-containing resin, i.e., the NCO/OH ratio. The NCO/OH ratio is preferably 0.6 to 1.4, and more preferably 0.8 to 1.2. With such a ratio, the effects of the present invention can be fully obtained.

In embodiment (3), the compound having a reactive silyl group can be the same as those described above.

(4) The resin component in the primer may include an epoxy resin, a polyamine compound, and a compound having a reactive silyl group.

In this embodiment (4), an epoxy resin can be used. Examples of such epoxy resins include flexible epoxy resins and rigid epoxy resins. If the epoxy resin contains at least a flexible epoxy resin, this is preferable in terms of improving the effects of the present invention, and advantageous effects can be obtained even in cases where the existing wall surface is one in which a sealant is filled in the joints between plate-like wall materials.

Examples of flexible epoxy resins include aliphatic modified epoxy resins, butadiene-based epoxy resins, ε-caprolactone modified epoxy resins, thiol-based epoxy resins, amine modified epoxy resins, rubber modified epoxy resins, urethane modified epoxy resins, polyol modified epoxy resins, and fatty acid modified epoxy resins. These can be used alone or in combination of two or more. Of these, fatty acid modified epoxy resins are preferred.

The ratio of the flexible epoxy resin in the epoxy resin of embodiment (4) (converted into solid content) is preferably 50% by weight or more, more preferably 70 to 100% by weight, from the viewpoints of adhesion to the base, conformability, etc.

Fatty acid modified epoxy resins are obtained by subjecting an aliphatic polybasic acid compound to an addition reaction with an epoxy resin. For example, an esterification reaction can be used for the addition reaction. Examples of the epoxy resins used here include bisphenol A type epoxy resins, bisphenol F type epoxy resins, and various other epoxy resins such as those exemplified by the hard epoxy resins described below. Examples of the aliphatic polybasic acid compounds include maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, citraconic acid, tetrahydrophthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic acid, hexahydrophthalic anhydride, cyclohexanedicarboxylic acid, succinic acid, malonic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, 1,12-docane diacid, and dimer acid. Among these, dimer acid is preferred.

Dimer acids are dimers of unsaturated fatty acids. Examples of unsaturated fatty acids that make up dimer acids include oleic acid, elaidic acid, cetoleic acid, sorbic acid, linoleic acid, linoleic acid, arachidonic acid, soybean oil fatty acids, tall oil fatty acids, and linseed oil fatty acids.

Dimer acid modified epoxy resin obtained by addition reaction of dimer acid with epoxy resin is suitable as an epoxy resin for undercoat materials. The ratio of dimer acid modified epoxy resin in the epoxy resin of the undercoat material (converted into solid content) is preferably 50% by weight or more, more preferably 70 to 100% by weight, from the viewpoint of adhesion to the base, conformability, etc.

Examples of hard epoxy resins include bisphenol type epoxy resins such as bisphenol A type epoxy resins and bisphenol F type epoxy resins, phenol novolac type epoxy resins such as phenol novolac type bisphenol A epoxy resins and phenol novolac type bisphenol F epoxy resins, novolac type epoxy resins such as cresol novolac type epoxy resins and bisphenol A novolac type epoxy resins, alicyclic epoxy resins, hydrogenated bisphenol A type epoxy resins, glycidyl ether type epoxy resins, bisphenol S type epoxy resins, biphenyl type epoxy resins, dicyclo type epoxy resins, naphthalene type epoxy resins, etc. These can be used alone or in combination of two or more.

The epoxy resin of embodiment (4) preferably has an epoxy equivalent (per solid content) of 300 to 3000 g/eq, more preferably 400 to 2000 g/eq, even more preferably 450 to 1500 g/eq, and particularly preferably 500 to 1100 g/eq. When the epoxy equivalent is equal to or greater than the lower limit, it is suitable in terms of conformability to the substrate, adhesion, etc. When the epoxy equivalent is equal to or less than the upper limit, it is suitable in terms of blister resistance, adhesion, suitability as a topcoat material, etc. The epoxy equivalent is the value obtained by dividing the molecular weight of the epoxy resin by the number of epoxy groups.

The polyamine compound in aspect (4) has two or more amino groups in one molecule and forms an epoxy resin coating by crosslinking with the epoxy resin. Examples of polyamine compounds include polyamine compounds such as aliphatic polyamines, alicyclic polyamines, aromatic polyamines, heterocyclic polyamines, aliphatic polyamides, alicyclic polyamides, aromatic polyamides, aliphatic polyamidoamines, alicyclic polyamidoamines, and aromatic polyamidoamines. These can be used alone or in combination of two or more. Among these, one or more polyamine compounds selected from aliphatic polyamines, aliphatic polyamides, and aliphatic polyamidoamines can be preferably used.

Such polyamine compounds preferably have an active hydrogen equivalent (per solid content) of 40 to 200 g/eq, more preferably 50 to 150 g/eq, and even more preferably 60 to 95 g/eq. By having the active hydrogen equivalent within the above range, sufficient effects can be obtained in terms of adhesion, etc. The active hydrogen equivalent is the value obtained by dividing the molecular weight of the polyamine compound by the number of hydrogen atoms in the amino group.

In aspect (4), the epoxy resin and polyamine compound can be used by setting each material so that the active hydrogen equivalent of the polyamine compound and the epoxy equivalent of the epoxy resin are combined in a ratio of [active hydrogen equivalent of polyamine compound/epoxy equivalent of epoxy resin] of preferably less than 0.4, more preferably 0.01 to 0.3, even more preferably 0.03 to 0.25, and particularly preferably 0.05 to 0.2. By using a combination of epoxy resin and polyamine compounds that satisfy such conditions, more favorable effects can be obtained in terms of adhesion, etc.

The compounding ratio of epoxy resin to polyamine compound is preferably set so that [(amount of polyamine compound/active hydrogen equivalent of polyamine compound)/(amount of epoxy resin/epoxy equivalent of epoxy resin)] is 1.0 or less, more preferably 0.2 to 1.0, even more preferably 0.4 to 0.98, particularly preferably 0.6 to 0.95, and most preferably 0.7 to 0.9. The amount and active hydrogen equivalent of the amine curing agent, and the amount and epoxy equivalent of the epoxy resin are all based on the solid content. When the compounding ratio of epoxy resin to polyamine compound is equal to or less than the upper limit, it is suitable in terms of adhesion, base followability, suitability as a topcoat material, etc., and when it is equal to or more than the lower limit, it is suitable in terms of curing property, adhesion, etc.

In aspect (4), the compound having a reactive silyl group can be the same as that described above. In aspect (4), a silane coupling agent is preferred, and in particular, one or more selected from an epoxy group-containing silane coupling agent and an amino group-containing silane coupling agent can be preferably used.

In aspect (4), the solids weight ratio of the polyamine compound to the silane coupling agent (polyamine compound:silane coupling agent) is preferably 10:90 to 90:10, more preferably 12:88 to 80:20, even more preferably 14:86 to 65:35, and particularly preferably 15:85 to 50:50. By using both components in such a ratio, adhesion can be further improved. This is particularly suitable for water-based primers.

The undercoat material in the present invention can contain a compound having a reactive silyl group within the range of 0.1 to 30% by weight, more preferably 0.2 to 25% by weight, and even more preferably 0.3 to 20% by weight, calculated as _SiO 2 in the solid content of the resin component. By having the mixture ratio of the compound having a reactive silyl group within such a range, the adhesion between the existing coating and the undercoat material coating, and the adhesion between the undercoat material coating and the topcoat material coating can be further improved, and it is also suitable in terms of preventing cracking of the undercoat material coating and the topcoat material coating.

The _SiO2 equivalent is the weight of silica ( _SiO2 ) that remains when a compound having an Si-O bond is completely hydrolyzed and then baked at 900°C. Generally, tetraalkoxysilanes, alkylalkoxysilanes, etc. react with water to undergo a hydrolysis reaction to become silanols, which then have the property of undergoing a condensation reaction between silanols or between silanols and alkoxy. When this reaction is carried to its ultimate state, it becomes silica ( _SiO2 ). These reactions are as follows:
RO(Si(OR) ₂ O) _n R+(n+1)H ₂ O→nSiO ₂ +(2n+2)ROH
(R represents an alkyl group; n represents an integer.)
The _SiO2 equivalent in the present invention is the amount of the remaining silica component calculated based on this reaction formula.

The undercoat material contains powder (m) (hereinafter also referred to as "(m) component") with an average particle size of 1 μm or less and/or powder (n) (hereinafter also referred to as "(n) component") with an oil absorption of 100 ml/100 g or more. In the present invention, the use of such an undercoat material makes it possible to maintain the finish state of the new coating formed on the above-mentioned existing wall surface for a long period of time. The reasons for this effect are not limited to the following, but are presumed to be due to the action of the specific powder in the undercoat material giving the undercoat material viscosity, making it easier for the undercoat material to be applied evenly along the unevenness of the existing wall surface, and further, the strength of the undercoat material coating is increased due to the cohesive force of the specific powder, etc., improving adhesion to the highly durable existing coating and improving resistance to various deterioration factors.

The average particle size of the (m) component is 1 μm or less, preferably 0.1 to 0.9 μm, and more preferably 0.2 to 0.8 μm. The (m) component having such an average particle size is considered to contribute to imparting viscosity to the primer due to the large specific surface area of the powder. By having the average particle size of the (m) component be equal to or greater than the lower limit, the viscosity of the primer can be appropriately controlled, the workability during application of the primer is sufficiently ensured, and the primer can be easily applied evenly along the unevenness of the existing wall surface. The average particle size is the average value measured using a laser diffraction particle size distribution measuring device (measurement conditions: distribution standard: volume, refractive index: 1.60-0.10i).

As the (m) component, various powders can be used without any particular limitations as long as they satisfy the above physical properties. Examples of the (m) component include titanium oxide, zinc oxide, aluminum oxide, magnesium oxide, calcium carbonate, glass powder, hollow resin particles, and various color pigments. These can be used alone or in combination of two or more. The oil absorption of the (m) component is preferably 500 ml/100 g or less, more preferably 5 to 200 ml/100 g, and even more preferably 8 to 80 ml/100 g. The oil absorption is a value measured according to JIS K5101-13-1:2004 "Refined linseed oil method".

The oil absorption of the (n) component is 100 ml/100 g or more, preferably 150 ml/100 g or more, more preferably 200 ml/100 g or more. The upper limit of the oil absorption of the (n) component is preferably 500 ml/100 g or less, more preferably 450 ml/100 g or less. The (n) component having such an oil absorption is thought to contribute to imparting viscosity to the undercoat material by absorbing the medium and resin components in the undercoat material. By having the oil absorption of the (n) component be equal to or less than the above upper limit, the viscosity of the undercoat material can be appropriately controlled, workability during application of the undercoat material is sufficiently ensured, and the undercoat material can be easily applied evenly along the unevenness of the existing wall surface.

As long as the above physical properties are satisfied, the material of the (n) component is not particularly limited and various powders can be used. Examples of the (n) component include zeolite, sodium sulfate, alumina, allophane, diatomaceous earth, hydrous silicon dioxide, vermiculite, perlite, Oya stone powder, activated clay, charcoal, activated carbon, wood powder, and shirasu balloons. These can be used alone or in combination of two or more. The average particle size of the (n) component is preferably 0.5 μm or more, more preferably 1 to 100 μm, and even more preferably 2 to 80 μm.

The total amount of the (m) and (n) components is 10 to 250 parts by weight, preferably 25 to 220 parts by weight, and more preferably 35 to 200 parts by weight, per 100 parts by weight of the solid content of the resin component. By using such a ratio of the (m) and (n) components, the above-mentioned powder action is fully exerted, and the finished state of the newly installed coating can be maintained for a long period of time. If the amount of the (m) and (n) components is less than the above lower limit, the action of imparting viscosity and improving strength in the primer will be insufficient, making it difficult to apply the primer evenly or insufficient adhesion, making it difficult to obtain the effects of the present invention. If the amount of the (m) and (n) components is more than the above upper limit, it will be difficult to obtain a viscosity suitable for applying the primer evenly, and the ratio of the resin component will be relatively low, which may result in insufficient adhesion.

In the primer, one or more types of powder (o) other than the components (m) and (n) (e.g., color pigments, extender pigments, etc. that do not satisfy the above physical property values) can also be used as long as the effect of the present invention is not significantly impaired.

The total amount of the (m) component, (n) component, and other powder (o) in the undercoat material, i.e., the total amount of all powder, is preferably 10 to 250 parts by weight, more preferably 25 to 220 parts by weight, and even more preferably 35 to 200 parts by weight, per 100 parts by weight of the solid content of the resin component. The total amount of the (m) component and the (n) component in the total amount of all powder is preferably 35% by weight or more, more preferably 45% by weight or more, even more preferably 55% by weight or more, and particularly preferably 65 to 100% by weight. Thus, an undercoat material in which the total amount of all powder is within the above range and the total powder contains a high ratio of the (m) component and the (n) component is preferable for fully obtaining the effects of the present invention, and is particularly suitable in that it can form a beautiful new coating while making use of the uneven pattern of the existing wall surface, and can maintain the finished state for a long period of time.

When the primer contains pigments such as components (m), (n), and (o), the pigment volume concentration of the primer is preferably 1-30%, more preferably 3-25%, even more preferably 5-23%, and particularly preferably 8-20%. By having the pigment volume concentration within the above range, it is possible to enhance the effect of forming a primer coating with excellent adhesion while making use of the shape of the base. Note that the pigment volume concentration is the volume percentage of the pigment contained in the dry coating film, and is a value calculated from the weight parts and specific gravity of the resin components and pigments that make up the primer. Note that the specific gravity of the resin components is 1.

The undercoat material may contain a thickener. Examples of thickeners include organic bentonite, fine silica, surface-treated calcium carbonate, amide wax, hydrogenated castor oil wax, benzylidene sorbitol, metal soap, polyethylene oxide, polymerized vegetable oil, polycarboxylic acid amine salts, xanthan gum, guar gum, polyacrylic acid compounds, polyvinyl alcohol, polyethylene oxide, and urethane-modified polyether compounds. These may be used alone or in combination of two or more.

The amount of thickener mixed (solid content) is preferably 0.1 to 10 parts by weight, more preferably 0.2 to 5 parts by weight, per 100 parts by weight of the solid content of the resin component. If the amount of thickener mixed is within this range, combined with the action of the above-mentioned (m) and (n) components, the primer will be more likely to be applied evenly along the irregularities of the existing wall surface, sufficient adhesion can be ensured, and the effects of the present invention can be stably obtained.

The non-volatile content of the primer (at the time of application) is preferably 30-90% by weight, preferably 40-80% by weight, and more preferably 45-75% by weight. This ratio of non-volatile content of the primer increases the effect of applying the primer evenly along the irregularities of the existing wall surface. The non-volatile content is a value measured using the method of JIS K5601-1-2, and the heating temperature is 105°C and the heating time is 60 minutes.

The undercoat material may contain various components other than those mentioned above, so long as the effects of the present invention are not significantly impaired. Examples of such components include aggregates, dyes, dehydrating agents, leveling agents, wetting agents, plasticizers, film-forming aids, antifreeze agents, preservatives, antifungal agents, anti-algae agents, antibacterial agents, dispersants, defoamers, adsorbents, fibers, crosslinking agents, UV absorbers, light stabilizers, antioxidants, and curing catalysts. Examples of the curing catalysts include organotin compounds, organoaluminum compounds, organotitanate compounds, acidic compounds, amine compounds, and alkaline compounds. The undercoat material of the present invention can be manufactured by uniformly mixing the above-mentioned various components by a conventional method. The form of the undercoat material can be, for example, a one-component type, a two-component type, or a multi-component type.

In the present invention, a primer that forms a coating with a different color tone and/or gloss from the existing wall surface can be used as the primer. In the present invention, by using such a primer, it is possible to fully confirm that a primer coating has been formed evenly along the unevenness of the existing wall surface over the entire uneven pattern of the existing wall surface, i.e., the entire existing wall surface including the concave and convex parts of the uneven pattern, as well as the boundaries between the concave and convex parts, and the like, and the effects of the present invention can be obtained even more stably.

The undercoat material that forms a coating with a different color tone from the existing wall surface is sufficient if the color tone of the coating (undercoat material coating) formed after application of the undercoat material can be visually recognized as being different from the color tone of the existing wall surface. For such undercoat materials, the color difference (ΔE) between the existing wall surface and the undercoat material coating is preferably 3 or more, more preferably 5 or more, and even more preferably 10 or more. For existing wall surfaces that have multiple areas with different color tones (e.g., spotted patterns, lattice patterns, etc.), it is sufficient if the color tone of the undercoat material coating is different from the color tone of the area that occupies the largest area of those areas.

The color difference (ΔE) is a value measured using a colorimeter. Specifically, it can be calculated by the following formula from the L ^* value, a ^* value, and b ^* value (average value of 10 measurement points) of the existing wall surface and the primer coating film. The L ^* value, a ^* value, and b ^* value of the primer coating film can be measured for the primer coating film formed on the existing wall surface.
<Formula> △E={(L ^* ₂ - L ^* ₁ ) ² + (a ^* ₂ - ^{a *} ₁ ) ² + (b ^* ₂ - ^{b *} ₁ ) ² } ^0.5
(In the formula, L ^* ₁ , a ^* ₁ , and b ^* ₁ are the L ^* , a ^* , and b ^* of the existing wall surface, respectively. L ^* ₂ , a ^* ₂ , and b ^* ₂ are the L ^* , a ^* , and b ^* of the undercoat coating, respectively.)

The primer material that forms a coating with a different gloss from the existing wall surface may be one in which the gloss of the coating (primer material coating) is visually recognizable as being different from the gloss of the existing wall surface. For such primer materials, the difference in gloss between the existing wall surface and the primer material coating is preferably 5 or more, more preferably 10 or more, and even more preferably 15 or more. For an existing wall surface that has multiple areas with different gloss, it is sufficient that the gloss of the primer material coating is different from the gloss of the area that occupies the largest area among those areas.

Glossiness is a value measured using a glossmeter. Specifically, it can be determined from the 60-degree specular glossiness (average value of 10 measurement points) of both the existing wall surface and the primer coating. The glossiness of the primer coating can be measured for the primer coating formed on the existing wall surface.

The color tone and gloss of the primer coating can be set, for example, by adjusting the type and ratio of the resin components, the type and ratio of the powder, etc. The gloss can also be adjusted, for example, by combining two or more types of resin.

The primer can be applied directly to the existing wall surface, but various pre-treatments can also be carried out as necessary. Pre-treatments include, for example, removing any existing coating that has deteriorated significantly, removing contaminants with high-pressure water washing, repairing with putty or filler, restoring the surface shape, etc. When applying new sealant to an existing wall surface, it is advisable to apply the primer approximately 2 to 10 days after applying the sealant.

A known painting tool can be used to apply the undercoat material, such as a spray, roller, brush, or trowel.
The amount of the primer applied may be appropriately determined depending on the surface shape of the existing wall surface, the painting equipment used, etc., but is preferably 0.03 to 0.5 kg/m ² , more preferably 0.05 to 0.3 kg/m ^2. The primer can also be appropriately diluted when painting.

The viscosity of the primer when applied is preferably 0.1 to 10 Pa·s, more preferably 0.2 to 5 Pa·s. By keeping the viscosity of the primer within this range, the effects of the present invention can be stably obtained. Note that the viscosity referred to here is the value determined by measuring the viscosity at 20 rpm (the guideline value at the fourth revolution) using a BH type viscometer, and the measurement temperature is 23°C.

The drying time for the primer is preferably at least 1 hour at room temperature (0 to 40°C), and more preferably about 2 to 200 hours.

In the present invention, the topcoat material is applied after the above-mentioned undercoat material is applied and dried. As the topcoat material in the present invention, a material that can utilize the uneven pattern of the existing wall surface is suitable. Specifically, usable topcoat materials include, for example, transparent topcoat materials and colored topcoat materials. Transparent topcoat materials contain resin components, and the coating exhibits transparency. Transparent topcoat materials may be those that form colored transparent coatings, and such transparent topcoat materials may contain, in addition to resin components, colored pigments, etc., within the range that does not impair transparency. Colored topcoat materials include those that contain resin components and colored pigments.

Various resins can be used as the resin component in the topcoat material. Examples of the resin include vinyl acetate resin, polyester resin, alkyd resin, vinyl chloride resin, epoxy resin, acrylic resin, urethane resin, acrylic silicone resin, fluororesin, etc., or composite resins of these. Among these, one or more types selected from acrylic resin, urethane resin, acrylic silicone resin, fluororesin, etc. are suitable. In addition, the form of such a resin component includes water-soluble resin, water-dispersible resin (resin emulsion), solvent-soluble resin, solventless resin, non-aqueous dispersion resin, powder resin, etc., among which, one or more types selected from water-soluble resin, water-dispersible resin, solvent-soluble resin, and non-aqueous dispersion resin are suitable. In addition, these resin components may have crosslinking reactivity. When a resin component having crosslinking reactivity is used, the durability, water resistance, weather resistance, chemical resistance, adhesion, etc. of the coating can be improved.

As coloring pigments, for example, known inorganic coloring pigments, organic coloring pigments, etc. can be used. By using one or more of these coloring pigments appropriately, the topcoat material can be set to the desired color tone. The mixing ratio of the coloring pigment in the coloring topcoat material is preferably 1 to 500 parts by weight, more preferably 5 to 200 parts by weight, and even more preferably 10 to 150 parts by weight, per 100 parts by weight of the solid content of the resin component.

Such a topcoat material may contain various components other than the above-mentioned components, so long as the effect of the present invention is not significantly impaired. Examples of such components include thickeners, film-forming agents, leveling agents, wetting agents, plasticizers, antifreeze agents, pH adjusters, body pigments, preservatives, antifungal agents, antialgae agents, antibacterial agents, dispersants, defoamers, adsorbents, fibers, crosslinking agents, coupling agents, UV absorbers, light stabilizers, antioxidants, low-pollution agents, hydrophilizing agents, water repellents, catalysts, solvents, and water. The topcoat material of the present invention can be manufactured by uniformly mixing the above-mentioned resin components, coloring pigments, and the various components described above as necessary by a conventional method. The form of the topcoat material can be, for example, a one-component type, a two-component type, or a multi-component type having more than one component. In addition, the degree of gloss of the topcoat material can be, for example, glossy, 70% gloss, 50% gloss, 30% gloss, matte, etc.

Specific examples of topcoat materials include weather-resistant topcoat paints for architecture (JIS K5658:2010), weather-resistant paints for steel structures (JIS K5659:2008), glossy synthetic resin emulsion paints (JIS K5660:2008), synthetic resin emulsion paints (JIS K5663:2008), multicolored pattern paints (JIS K5667:2003), synthetic resin emulsion pattern paints (JIS K5668:2010), acrylic resin-based non-aqueous dispersion paints (JIS K5670:2008), and high solar reflectance paints for roofs (JIS K5675:2011).

In painting the topcoat material, a known painting tool can be used. Examples of the painting tool that can be used include a spray, a roller, and a brush.
The amount of topcoat material to be applied may be set appropriately depending on the surface shape of the existing wall surface, the type of topcoat material, the type of painting equipment, etc., but is preferably 0.05 to 0.5 kg/m ² , more preferably 0.1 to 0.4 kg/m ^2. When painting, the topcoat material can also be appropriately diluted as necessary.

In the present invention, one or more types of topcoat materials can be used. When using two or more types of topcoat materials, it is possible to achieve a multi-colored appearance by using topcoats with different color tones and applying different colors.

The following examples will clarify the features of the present invention.

[Test Example 1]
In Test Example 1, the following undercoat materials 1-1 to 1-11 were prepared as undercoat materials, and tests were conducted using these undercoat materials.

(Undercoat material 1-1)
a base material including a non-aqueous dispersion type acrylic polyol {hydroxyl value: 50 KOHmg/g, weight average molecular weight: 70000, glass transition temperature: 38°C, solid content: 50% by weight, medium: mineral spirits (aniline point: 42°C)}, powder m1 (titanium oxide, average particle size: 0.3 μm, oil absorption: 13 ml/100 g, specific gravity: 4.2), amide wax, solvent naphtha (aniline point: 13°C), and a silicone-based defoaming agent;
A mixture of a polyisocyanate compound (1,6-diisocyanatohexane derivative, solid content: 100% by weight), a tetraalkoxysilane compound (isobutyl alcohol modified product of tetramethoxysilane condensate), and a hardener containing mineral spirits (NCO/OH ratio: 1.0).
Pigment volume concentration: 14%, non-volatile content of primer: 61% by weight, ratio of compound having reactive silyl group in resin solids: 0.5% by weight ( _SiO2 equivalent), powder amount: 70 parts by weight per 100 parts by weight of resin solids, thickener amount (solids): 1 part by weight per 100 parts by weight of resin solids.

(Undercoat material 1-2)
A base material including a non-aqueous dispersion type acrylic polyol (same as above), powder m1 (same as above), amide wax, solvent naphtha, and a silicone-based defoaming agent;
A mixture of a polyisocyanate compound (same as above), a tetraalkoxysilane compound (same as above), and a hardener containing mineral spirits (NCO/OH ratio: 1.0).
Pigment volume concentration: 22%, non-volatile content of primer: 63% by weight, ratio of compound having reactive silyl group in resin solids: 0.5% by weight ( _SiO2 equivalent), powder amount: 120 parts by weight per 100 parts by weight of resin solids, thickener amount (solids): 0.8 parts by weight per 100 parts by weight of resin solids.

(Undercoat material 1-3)
A base material including a non-aqueous dispersion type acrylic polyol (same as above), powder n1 (hydrated silicon dioxide, average particle size: 6 μm, oil absorption: 340 ml/100 g, specific gravity: 2.0), amide wax, solvent naphtha, and a silicone-based defoaming agent;
A mixture of a polyisocyanate compound (same as above), a tetraalkoxysilane compound (same as above), and a hardener containing mineral spirits (NCO/OH ratio: 1.0).
Pigment volume concentration: 7%, non-volatile content of primer: 59% by weight, ratio of compound having reactive silyl group in resin solids: 0.5% by weight ( _SiO2 equivalent), powder amount: 15 parts by weight per 100 parts by weight of resin solids, thickener amount (solids): 1.2 parts by weight per 100 parts by weight of resin solids.

(Undercoat material 1-4)
A base material including a non-aqueous dispersion type acrylic polyol (same as above), powder n1 (same as above), amide wax, solvent naphtha, and a silicone-based defoaming agent;
A mixture of a polyisocyanate compound (same as above), a tetraalkoxysilane compound (same as above), and a hardener containing mineral spirits (NCO/OH ratio: 1.0).
Pigment volume concentration: 13%, non-volatile content of primer: 57% by weight, ratio of compound having reactive silyl group in resin solids: 0.5% by weight ( _SiO2 equivalent), powder amount: 30 parts by weight per 100 parts by weight of resin solids, thickener amount (solids): 1 part by weight per 100 parts by weight of resin solids.

(Undercoat 1-5)
A base material including a non-aqueous dispersion type acrylic polyol (same as above), powder n1 (same as above), amide wax, solvent naphtha, and a silicone-based defoaming agent;
A mixture of a polyisocyanate compound (same as above), a tetraalkoxysilane compound (same as above), and a hardener containing mineral spirits (NCO/OH ratio: 1.0).
Pigment volume concentration: 20%, non-volatile content of primer: 58% by weight, ratio of compound having reactive silyl group in resin solids: 0.5% by weight ( _SiO2 equivalent), powder amount: 50 parts by weight per 100 parts by weight of resin solids, thickener amount (solids): 0.8 parts by weight per 100 parts by weight of resin solids.

(Undercoat material 1-6)
A base material including a non-aqueous dispersion type acrylic polyol (same as above), powder n1 (same as above), amide wax, solvent naphtha, and a silicone-based defoaming agent;
A mixture of a polyisocyanate compound (same as above), a tetraalkoxysilane compound (same as above), and a hardener containing mineral spirits (NCO/OH ratio: 1.0).
Pigment volume concentration: 25%, non-volatile content of primer: 58% by weight, ratio of compound having reactive silyl group in resin solids: 0.5% by weight ( _SiO2 equivalent), powder amount: 66 parts by weight per 100 parts by weight of resin solids, thickener amount (solids): 0.6 parts by weight per 100 parts by weight of resin solids.

(Undercoat material 1-7)
A base material including a non-aqueous dispersion type acrylic polyol (same as above), powder n2 (hydrated silicon dioxide, average particle size: 10 μm, oil absorption: 310 ml/100 g, specific gravity: 2.0), amide wax, solvent naphtha, and a silicone-based defoaming agent;
A mixture of a polyisocyanate compound (same as above), a tetraalkoxysilane compound (same as above), and a hardener containing mineral spirits (NCO/OH ratio: 1.0).
Pigment volume concentration: 25%, non-volatile content of primer: 58% by weight, ratio of compound having reactive silyl group in resin solids: 0.5% by weight ( _SiO2 equivalent), powder amount: 66 parts by weight per 100 parts by weight of resin solids, thickener amount (solids): 0.6 parts by weight per 100 parts by weight of resin solids.

(Undercoat material 1-8)
A base material including a non-aqueous dispersion type acrylic polyol (same as above), powder m1 (same as above), powder n2 (same as above), amide wax, solvent naphtha, and a silicone-based defoaming agent;
A mixture of a polyisocyanate compound (same as above), a tetraalkoxysilane compound (same as above), and a hardener containing mineral spirits (NCO/OH ratio 1.0).
Pigment volume concentration: 24%, non-volatile content of primer: 58% by weight, ratio of compound having reactive silyl group in resin solids: 0.5% by weight ( _SiO2 equivalent), powder amount: 50 parts by weight of powder m1 and 40 parts by weight of powder n2 per 100 parts by weight of resin solids, thickener amount (solids): 0.8 parts by weight per 100 parts by weight of resin solids.

(Undercoat 1-9)
A base material including a non-aqueous dispersion type acrylic polyol (same as above), powder m1 (same as above), amide wax, solvent naphtha, and a silicone-based defoaming agent;
A mixture of a polyisocyanate compound (same as above), a tetraalkoxysilane compound (same as above), and a hardener containing mineral spirits (NCO/OH ratio: 1.0).
Pigment volume concentration: 14%, non-volatile content of primer: 61% by weight, ratio of compound having reactive silyl group in resin solids: 3% by weight ( _SiO2 equivalent), powder amount: 70 parts by weight per 100 parts by weight of resin solids, thickener amount (solids): 1 part by weight per 100 parts by weight of resin solids.

(Undercoat material 1-10)
A base material including a non-aqueous dispersion type acrylic polyol (same as above), powder O1 (calcium carbonate, average particle size: 6 μm, oil absorption: 20 ml/100 g, specific gravity: 2.6), amide wax, solvent naphtha, and a silicone-based defoaming agent;
A mixture of a polyisocyanate compound (same as above), a tetraalkoxysilane compound (same as above), and a hardener containing mineral spirits (NCO/OH ratio: 1.0).
Pigment volume concentration: 7%, non-volatile content of primer: 61% by weight, ratio of compound having reactive silyl group in resin solids: 0.5% by weight ( _SiO2 equivalent), powder amount: 20 parts by weight per 100 parts by weight of resin solids, thickener amount (solids): 1.5 parts by weight per 100 parts by weight of resin solids.

(Undercoat material 1-11)
A base material including a non-aqueous dispersion type acrylic polyol (same as above), powder o2 (calcium carbonate, average particle size: 24 μm, oil absorption: 20 ml/100 g, specific gravity: 2.6), amide wax, solvent naphtha, and a silicone-based defoaming agent;
A mixture of a polyisocyanate compound (same as above), a tetraalkoxysilane compound (same as above), and a hardener containing mineral spirits (NCO/OH ratio: 1.0).
Pigment volume concentration: 7%, non-volatile content of primer: 61% by weight, ratio of compound having reactive silyl group in resin solids: 0.5% by weight ( _SiO2 equivalent), powder amount: 20 parts by weight per 100 parts by weight of resin solids, thickener amount (solids): 1.5 parts by weight per 100 parts by weight of resin solids.

(Test Example 1-1)
○ Test i
As the existing wall surface, a brown ceramic siding boat deteriorated by outdoor exposure (having tile-like convex and concave portions (joints) on the surface, an amorphous uneven pattern on the convex portions, and an inorganic clear coating as the outermost coating film) was prepared. The entire surface of this existing wall surface was spray-painted with the undercoat material 1-1 at a coating amount of 0.1 kg/ ^m2 and dried. Here, the coating of the undercoat material 1-1 is significantly different in color from the existing wall surface (color difference 40), and it was easy to confirm that the undercoat material coating was formed evenly over the entire uneven pattern of the existing wall surface while making use of the uneven pattern. Next, a topcoat material (light brown acrylic silicone resin paint) was spray-painted at a coating amount of 0.2 kg/ ^m2 , and the test specimen was prepared by drying and curing for 7 days. In addition, all painting and curing processes were performed under standard conditions (temperature 23 ° C, relative humidity 50%).

The specimens prepared by the above method were exposed for 500 hours in an accelerated weather resistance tester (Metal Weather; manufactured by Daipla Wintes Co., Ltd.), after which the appearance of the specimen surface was observed for changes (floating and peeling). Next, cross-cuts were made in the coating at each location of the uneven pattern with a utility knife, and tape was applied to the cross-cut areas and peeled off to confirm adhesion. As a result, in Test Example 1-1, there was no change in appearance due to the accelerated weather resistance test, and no peeling was observed in any location.

Test II
As an existing wall surface, a brown ceramic siding board deteriorated by outdoor exposure (having tile-like convex and concave portions (joints) on the surface, with an irregular uneven pattern on the convex portions, and a fluororesin clear coating as the outermost coating) was prepared. Using this existing wall surface, a test specimen was prepared in the same manner as in Test i, and the test was conducted.

Test iii
As an existing wall surface, a brown ceramic siding board deteriorated by outdoor exposure (having tile-like convex and concave portions (joints) on the surface, with an irregular uneven pattern on the convex portions, and an acrylic silicone resin colored coating as the top layer coating) was prepared. Using this existing wall surface, a test specimen was prepared in the same manner as in Test i, and the test was conducted.

The test results are shown in Table 1. In Table 1, the condition after the primer coating was rated as follows: "A" indicates that the color difference between the existing wall surface and the primer coating was 10 or more, or the gloss difference was 15 or more; "B" indicates that the color difference between the existing wall surface and the primer coating was 5 to 10 or less, or the gloss difference was 10 to 15; "C" indicates that the color difference between the existing wall surface and the primer coating was 3 to 5 or less, or the gloss difference was 5 to 10; and "D" indicates that the color difference between the existing wall surface and the primer coating was less than 3 or the gloss difference was less than 5. The accelerated weather resistance test was rated as follows: "A" indicates that there was no change in appearance and no peeling was observed in any part; and "D" indicates that there was a clear change in appearance or a lot of peeling.

(Test Example 1-2)
Except for using the undercoat material 1-2 instead of the undercoat material 1-1, a test specimen was prepared in the same manner as in Test Example 1-1, and the test was carried out. After the undercoat material 1-2 was applied, the coating of the undercoat material 1-2 was significantly different in color from the existing wall surface, and it was easy to confirm that the undercoat material coating was formed evenly over the entire uneven pattern of the existing wall surface while making use of the uneven pattern. The test results are shown in Table 1.

(Test Example 1-3)
Except for using the undercoat material 1-3 instead of the undercoat material 1-1, a test specimen was prepared in the same manner as in Test Example 1-1, and the test was carried out. After the undercoat material 1-3 was applied, the coating of the undercoat material 1-3 had a significantly different glossiness from the existing wall surface, and it was easy to confirm that the undercoat material coating was formed evenly over the entire uneven pattern of the existing wall surface while making use of the uneven pattern. The test results are shown in Table 1.

(Test Example 1-4)
Except for using the undercoat material 1-4 instead of the undercoat material 1-1, a test specimen was prepared in the same manner as in Test Example 1-1, and the test was carried out. After the undercoat material 1-4 was applied, the coating of the undercoat material 1-4 had a significantly different glossiness from the existing wall surface, and it was easy to confirm that the undercoat material coating was formed evenly over the entire uneven pattern of the existing wall surface while making use of the uneven pattern. The test results are shown in Table 1.

(Test Example 1-5)
Except for using the undercoat material 1-5 instead of the undercoat material 1-1, a test specimen was prepared in the same manner as in Test Example 1-1, and the test was carried out. After the undercoat material 1-5 was applied, the coating of the undercoat material 1-5 had a significantly different glossiness from the existing wall surface, and it was easy to confirm that the undercoat material coating was formed evenly over the entire uneven pattern of the existing wall surface while making use of the uneven pattern. The test results are shown in Table 1.

(Test Example 1-6)
Except for using the undercoat material 1-6 instead of the undercoat material 1-1, a test specimen was prepared in the same manner as in Test Example 1-1, and the test was carried out. After the undercoat material 1-6 was applied, the coating of the undercoat material 1-6 had a significantly different glossiness from the existing wall surface, and it was easy to confirm that the undercoat material coating was formed evenly over the entire uneven pattern of the existing wall surface while making use of the uneven pattern. The test results are shown in Table 1.

(Test Example 1-7)
Except for using the undercoat material 1-7 instead of the undercoat material 1-1, a test specimen was prepared in the same manner as in Test Example 1-1, and the test was carried out. After the undercoat material 1-7 was applied, the coating of the undercoat material 1-7 had a significantly different glossiness from the existing wall surface, and it was easy to confirm that the undercoat material coating was formed evenly over the entire uneven pattern of the existing wall surface while making use of the uneven pattern. The test results are shown in Table 1.

(Test Example 1-8)
Except for using the undercoat material 1-8 instead of the undercoat material 1-1, a test specimen was prepared in the same manner as in Test Example 1-1, and the test was carried out. After the undercoat material 1-8 was applied, the coating of the undercoat material 1-8 was significantly different in color tone and gloss from the existing wall surface, and it was easy to confirm that the undercoat material coating was formed evenly over the entire uneven pattern of the existing wall surface while making use of the uneven pattern. The test results are shown in Table 1.

(Test Example 1-9)
Except for using the undercoat material 1-9 instead of the undercoat material 1-1, a test specimen was prepared in the same manner as in Test Example 1-1, and the test was carried out. After the undercoat material 1-9 was applied, the coating of the undercoat material 1-9 was significantly different in color from the existing wall surface, and it was easy to confirm that the undercoat material coating was formed evenly over the entire uneven pattern of the existing wall surface while making use of the uneven pattern. The test results are shown in Table 1.

(Test Example 1-10)
Except for using the undercoat material 1-10 instead of the undercoat material 1-1, a test specimen was prepared in the same manner as in Test Example 1-1 and tested. After the undercoat material 1-10 was applied, the undercoat material 1-10 coating did not show any difference in color tone from the existing wall surface, and the gloss level was also not very different, so it was not easy to confirm that the undercoat material coating was formed evenly over the entire uneven pattern of the existing wall surface. The test results are shown in Table 1.

(Test Example 1-11)
Except for using the undercoat material 1-11 instead of the undercoat material 1-1, a test specimen was prepared in the same manner as in Test Example 1-1 and tested. After the undercoat material 1-11 was applied, the coating of the undercoat material 1-11 had no difference in color tone from the existing wall surface, and no significant difference in gloss was observed, so it was not easy to confirm that the undercoat material coating had been formed evenly over the entire uneven pattern of the existing wall surface. The test results are shown in Table 1.

Test Examples 1-1 to 1-9 correspond to working examples, and generally showed better results than Test Examples 1-10 and 1-11 (corresponding to comparative examples).

[Test Example 2]
In Test Example 2, the following base materials Q1 to Q7 and hardeners R1 to R5 were combined to prepare undercoat materials 2-1 to 2-12, and tests were conducted using these undercoat materials.

(Main agent Q1)
75 parts by weight of epoxy resin a {dimer acid modified epoxy resin solution, solid content: 60% by weight, epoxy equivalent (per solid content): 780 g/eq, medium: mineral spirits (aniline point 42° C.) and solvent naphtha (aniline point 13° C.)}, 18 parts by weight of powder m1 (titanium oxide, average particle size: 0.3 μm , oil absorption: 13 ml/100 g, specific gravity: 4.2), 4 parts by weight of solvent naphtha (same as above), and 4 parts by weight of additives (dispersant, thickener, and defoamer) were uniformly mixed in a conventional manner to produce main agent Q1.

(Main agent Q2)
62 parts by weight of epoxy resin a (same as above), 30 parts by weight of powder m1 (same as above), 4 parts by weight of solvent naphtha (same as above), and 4 parts by weight of additives (dispersant, thickener, and defoamer) were uniformly mixed in a conventional manner to produce main agent Q2.

(Main agent Q3)
55 parts by weight of epoxy resin a (same as above), 35 parts by weight of powder m1 (same as above), 6 parts by weight of solvent naphtha (same as above), and 4 parts by weight of additives (dispersant, thickener, and defoamer) were uniformly mixed in a conventional manner to produce main agent Q3.

(Main agent Q4)
38 parts by weight of epoxy resin a (same as above), 15 parts by weight of powder m1 (same as above), 30 parts by weight of heavy calcium carbonate (specific gravity 2.7), 12 parts by weight of solvent naphtha (same as above), and 5 parts by weight of additives (dispersant, thickener, and defoamer) were uniformly mixed in a conventional manner to produce main agent Q4.

(Main agent Q5)
65 parts by weight of epoxy resin a (same as above), 29 parts by weight of solvent naphtha (same as above), and 6 parts by weight of additives (thickener and defoamer) were uniformly mixed in a conventional manner to produce base agent Q5.

(Main agent Q6)
40 parts by weight of epoxy resin a (same as above), 50 parts by weight of solvent naphtha (same as above), and 10 parts by weight of additives (thickener and defoamer) were uniformly mixed in a conventional manner to produce base agent Q6.

(Main agent Q7)
65 parts by weight of epoxy resin a (same as above), 18 parts by weight of powder o1 (calcium carbonate, average particle size: 6 μm, oil absorption: 20 ml/100 g, specific gravity: 2.6), 12 parts by weight of solvent naphtha (same as above), and 5 parts by weight of additives (thickener and defoamer) were uniformly mixed in a conventional manner to produce main agent Q7.

(Main agent Q8)
60 parts by weight of epoxy resin b {aqueous epoxy resin (water dispersion of bisphenol A type epoxy resin), solid content: 45% by weight, epoxy equivalent (per solid content): 510 g/eq, medium: water}, 25 parts by weight of powder m1 (same as above), 3 parts by weight of an ether-based solvent, and 2 parts by weight of additives (dispersant, thickener, and defoamer) were uniformly mixed in a conventional manner to produce main agent Q8.

(Curing agent R1)
Curing agent R1 was produced by uniformly mixing 15 parts by weight of polyamine compound a {aliphatic polyamide amine, solid content: 100% by weight, active hydrogen equivalent (per solid content): 80 g/eq}, 4 parts by weight of a silane compound {N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane}, 16 parts by weight of an alcohol-based solvent, and 65 parts by weight of solvent naphtha (same as above) in a conventional manner.

(Curing agent R2)
15 parts by weight of polyamine compound a (same as above), 16 parts by weight of alcohol-based solvent, and 69 parts by weight of solvent naphtha (same as above) were uniformly mixed in a conventional manner to produce hardener R2.

(Curing agent R3)
25 parts by weight of polyamine compound b {aliphatic polyamide amine, solid content: 100% by weight, active hydrogen equivalent (per solid content): 180 g/eq}, 4 parts by weight of silane compound (same as above), 11 parts by weight of alcohol-based solvent, and 60 parts by weight of solvent naphtha (same as above) were uniformly mixed in a conventional manner to produce curing agent R3.

(Curing agent R4)
35 parts by weight of polyamine compound c {water-soluble modified aliphatic polyamine resin, solid content: 80% by weight, active hydrogen equivalent (per solid content): 140 g/eq, medium: water} and 65 parts by weight of the silane compound (same as above) were uniformly mixed in a conventional manner to produce curing agent R4.

(Hardening agent R5)
75 parts by weight of the polyamine compound c (same as above) and 25 parts by weight of the silane compound (same as above) were uniformly mixed in a conventional manner to prepare a curing agent R5.

(Undercoat material 2-1)
The above-mentioned base agent Q1 (100 parts by weight) and the above-mentioned curing agent R1 (25 parts by weight) were uniformly mixed to prepare the undercoat material 2-1. The characteristic values of this undercoat material are as shown in Table 1.
The compounding ratio of epoxy resin to amine curing agent [(amount of polyamine compound/active hydrogen equivalent of polyamine compound)/(amount of epoxy resin/epoxy equivalent of epoxy resin)] (referred to as "compounding ratio" in Table 1) was 0.81,
Pigment volume concentration is 8%,
The non-volatile content of the primer (referred to as "non-volatile content" in Table 2) was 54% by weight.
The ratio of the compound having a reactive silyl group in the resin solid content ( _SiO2 equivalent, indicated as " _SiO2 equivalent amount" in Table 2) is 0.5% by weight,
The amount of powder is 36 parts by weight per 100 parts by weight of the solid content of the resin component.
The amount of the thickener (solid content) was 1.6 parts by weight per 100 parts by weight of the solid content of the resin component.

(Undercoat material 2-2)
The above-mentioned base agent Q2 (100 parts by weight) and the above-mentioned curing agent R1 (20 parts by weight) were uniformly mixed to prepare the undercoat material 2-2. The characteristic values of this undercoat material 2-2 are as shown in Table 2.

(Undercoat material 2-3)
The above-mentioned base agent Q3 (100 parts by weight) and the above-mentioned curing agent R1 (18 parts by weight) were uniformly mixed to prepare the undercoat material 2-3. The characteristic values of this undercoat material 2-3 are as shown in Table 2.

(Undercoat material 2-4)
The above-mentioned base agent Q2 (100 parts by weight) and the above-mentioned curing agent R1 (22 parts by weight) were uniformly mixed to prepare the undercoat material 2-4. The characteristic values of this undercoat material 2-4 are as shown in Table 2.

(Undercoat 2-5)
The above-mentioned base agent Q2 (100 parts by weight) and the above-mentioned curing agent R1 (30 parts by weight) were uniformly mixed to prepare the undercoat material 2-5. The characteristic values of this undercoat material 2-5 are as shown in Table 2.

(Undercoat material 2-6)
The above-mentioned base agent Q2 (100 parts by weight) and the above-mentioned curing agent R2 (20 parts by weight) were uniformly mixed to prepare the undercoat material 2-6. The characteristic values of this undercoat material 2-6 are as shown in Table 2.

(Undercoat material 2-7)
The above-mentioned base agent Q2 (100 parts by weight) and the above-mentioned curing agent R3 (28 parts by weight) were uniformly mixed to prepare the undercoat material 2-7. The characteristic values of this undercoat material 2-7 are as shown in Table 2.

(Undercoat material 2-8)
The above-mentioned base agent Q4 (100 parts by weight) and the above-mentioned curing agent R3 (16 parts by weight) were uniformly mixed to prepare the undercoat material 2-8. The characteristic values of this undercoat material 2-8 are as shown in Table 2.

(Undercoat material 2-9)
The above-mentioned base agent Q5 (100 parts by weight) and the above-mentioned curing agent R3 (28 parts by weight) were uniformly mixed to prepare the undercoat material 2-9. The characteristic values of this undercoat material 2-9 are as shown in Table 2.

(Undercoat material 2-10)
The above-mentioned base agent Q6 (100 parts by weight) and the above-mentioned curing agent R3 (17 parts by weight) were uniformly mixed to prepare the undercoat material 2-10. The characteristic values of this undercoat material 2-10 are as shown in Table 2.

(Undercoat material 2-11)
The above-mentioned base agent Q7 (100 parts by weight) and the above-mentioned curing agent R3 (28 parts by weight) were uniformly mixed to prepare the undercoat material 2-11. The characteristic values of this undercoat material 2-11 are as shown in Table 2.

(Undercoat material 2-12)
The above-mentioned base agent Q8 (100 parts by weight) and the above-mentioned curing agent R4 (20 parts by weight) were uniformly mixed to prepare the undercoat material 2-12. The characteristic values of this undercoat material 2-12 are as shown in Table 2.

(Undercoat material 2-13)
The above-mentioned base agent Q8 (100 parts by weight) and the above-mentioned curing agent R5 (10 parts by weight) were uniformly mixed to prepare the undercoat material 2-13. The characteristic values of this undercoat material 2-13 are as shown in Table 2.

(Test Examples 2-1 to 2-13)
Except for using the undercoat material 2-1 to 2-13 instead of the undercoat material 1-1, the test specimens were prepared in the same manner as in Test Example 1-1 and tested. The test results are shown in Table 3. Among them, for Test Examples 2-1 to 2-8, 2-12, and 2-13 (corresponding to the examples), the color tone of the undercoat material coating was different from the color tone of the existing wall surface, and it was easy to confirm that the undercoat material coating was formed evenly over the entire uneven pattern of the existing wall surface, and the results were generally good compared to Test Examples 2-9, 2-10, and 2-11 (corresponding to the comparative examples).

Claims (2)

A decorative method for existing walls that have deteriorated over time, comprising the steps of:
The existing wall surface has an uneven pattern on its surface.
The present invention provides a method for manufacturing a steel sheet having an existing coating film, the method comprising the steps of: providing an existing coating film of at least one type selected from an inorganic coating film, an organic-inorganic composite coating film, and a fluororesin coating film;
For the above existing wall,
The composition comprises a resin component, and a powder (m) having an average particle diameter of 1 μm or less and/or a powder (n) having an oil absorption of 100 ml/100 g or more and an average particle diameter of 2 to 100 μm,
the resin component includes a compound having a reactive silyl group, the compound having a reactive silyl group being one or more selected from a tetraalkoxysilane compound, an alkylalkoxysilane compound, and a silane coupling agent;
The powder (n) is one or more selected from zeolite, sodium sulfate, alumina, allophane, diatomaceous earth, hydrous silicon dioxide, vermiculite, perlite, Oya stone powder, activated clay, charcoal, activated carbon, wood powder, and shirasu balloon;
The total amount of the powder (m) and the powder (n) is 10 to 250 parts by weight per 100 parts by weight of the solid content of the resin component, and a pigment volume concentration of 1 to 30% is applied as a base coat material, and after the coating is dried, a top coat material is applied. This is a cosmetic method characterized by the above.
The oil absorption amount is a value measured by the method of JIS K5101-13-1:2004 "Refined linseed oil method". 2. The decorative method according to claim 1, wherein the existing wall surface is constituted by a plurality of plate-shaped wall materials having an uneven pattern on a surface and an existing coating.