JP2625897B2 - Coating method of cement base material - Google Patents

Description

Description of the Invention [Object of the Invention] (Field of Industrial Application) The present invention relates to a method for coating a cement-based substrate, and more particularly, to a method for applying a specific colored paint as a base coat, The present invention relates to a coating method for forming a coating material having extremely excellent durability by applying and curing a clear coating material containing a fluoroolefin-based copolymer, a curing agent and an ultraviolet absorber as essential components as a top coat. .

(Conventional technology and its problems) Cement-based materials such as concrete, asbestos slate, mortar, ALC plate, calcium silicate-based materials, gypsum / slag-based materials are widely used in construction and building material applications. Solution-type acrylic resin-based coloring paints have been applied for the purpose of imparting cosmetics and improving durability.
However, the coating film obtained by applying such a coating material has insufficient weather resistance, resulting in a decrease in gloss due to prolonged exposure, which impairs aesthetics. Cannot be sufficiently prevented.

In order to improve such drawbacks, there has been proposed a method of applying a color paint having a solution-type fluoroolefin copolymer as a base resin as a finish paint (Japanese Patent Publication No. Sho 62).
-16141 publication).

However, this coating method also has a disadvantage that gloss is reduced or discoloration is increased due to long-term exposure.

(Problems to be Solved by the Invention) The inventors of the present invention have conducted intensive studies to improve such disadvantages, and as a result, directly on a cement-based substrate or on a cement-based substrate on which an organic coating film was previously formed. A solution type comprising a specific solution type fluoroolefin copolymer resin-based coloring paint as a base and then a specific fluoroolefin type copolymer, a curing agent and an ultraviolet absorber as essential components as a finish paint. It has been found that a coating having extremely excellent durability can be obtained by applying the clear paint of the present invention, and the present invention has been completed.

[Configuration of the invention]

(Means for Solving the Problems) In summary of the present invention, the present invention relates to a method in which at least two per molecule are directly coated on a cement-based substrate or on a cement-based substrate on which an organic coating film is previously formed. A solution type comprising, as essential components, a fluoroolefin-based copolymer (A) soluble in a solvent containing a reactive functional group, a curing agent (B) capable of reacting with the reactive functional group, and a coloring material (C). Is applied and cured if necessary, and then, as a top coat, a fluoroolefin copolymer (D) soluble in a solvent containing at least two reactive functional groups per molecule. A cement type base, which is applied and cured by applying a solution type clear coating [II] comprising, as essential components, a curing agent (E) and an ultraviolet absorber (F) capable of reacting with the reactive functional group. Lumber The present invention relates to instrumentation method.

 Hereinafter, the configuration of the present invention will be described in detail.

First, a solvent-soluble fluoroolefin-based base resin component constituting a solution-type colored coating [I] used as a base coat or a solution-type clear coating [II] used as a top coat in the present invention. The copolymer (A) or (D) will be described.

The above-mentioned solvent-soluble fluoroolefin-based copolymer (A) or (D) refers to vinyl fluoride, vinylidene fluoride, trifluoroethylene, tetrafluoroethylene, bromotrifluoroethylene, chlorotrifluoroethylene, or pentane. A fluoroolefin unit such as fluoropropylene, hexafluoropropylene or (per) fluoroalkyl trifluorovinyl ether (where the number of carbon groups of the (per) fluoroalkyl group is 1 to 18) is contained as an essential component, and a hydroxyl group, Contains at least two reactive functional groups such as epoxy group, carboxyl group, trialkylsilyloxy group, trialkylsilyloxycarbonyl group, amino group, isocyanate group, amide group and carboxylic anhydride group on average in one molecule. Copolymer known and used Those that are soluble referred to finger to agents.

Such a fluoroolefin copolymer (A) or (D) is a fluoroolefin monomer (a) as described above, a vinyl monomer (b) containing a reactive functional group as described above, and A method of copolymerizing a monomer (c) copolymerizable therewith, by reacting a fluoroolefin copolymer containing a specific reactive functional group prepared by a prior method with a specific modifier. In the case of preparing a copolymer containing a hydroxyl group as a reactive functional group, for example, a method of converting into a fluoroolefin-based copolymer containing a different reactive functional group, a fluoroolefin and a carboxylic acid vinyl ester prepared in advance are used. The copolymer as an essential component can be prepared by a method of hydrolysis as disclosed in JP-A-59-219372 and JP-A-60-158209.

Specific examples of the vinyl monomer having a reactive functional group used when preparing the fluoroolefin copolymer (A) or (D) by the above method include 2
-Hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether, 2-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, 3-
Hydroxybutyl vinyl ether, 2-hydroxy-2
-Methylpropyl vinyl ether, 5-hydroxypentyl vinyl ether, 6-hydroxyhexyl vinyl ether, 2-hydroxyethyl allyl ether, 3-hydroxypropyl allyl ether, 4-hydroxybutyl allyl ether, 2-hydroxyethyl methacrylate or 2-hydroxyethyl acrylate Monomers containing a hydroxyl group such as 2-dimethylaminoethyl vinyl ether, 3-dimethylaminopropyl vinyl ether, 2-diethylaminoethyl vinyl ether, 3-diethylaminopropyl vinyl ether, 4-dimethylaminobutyl vinyl ether, p-dimethylaminoethylstyrene , P-diethylaminoethylstyrene, 2-dimethylaminoethyl methacrylate or 2-dimethylaminoethyl Monomers containing such amino group of acrylate, succinic acid mono-vinyl esters, adipic acid monovinyl ester, sebacic acid monovinyl ester,
Monomers containing a carboxyl group such as acrylic acid, methacrylic acid or crotonic acid; maleic anhydride,
Monomers containing carboxylic anhydride groups, such as itaconic anhydride or trimellitic anhydride monovinyl ester;
Monomers containing an epoxy group such as glycidyl vinyl ether, glycidyl acrylate or glycidyl methacrylate; monomers containing an isocyanate group such as vinyl isocyanate, allyl isocyanate or 2-isocyanatoethyl methacrylate;
Monomers containing an amide group such as acrylamide, methacrylamide, N-butoxymethylacrylamide or N-methylolacrylamide; 2-trimethylsilyloxyethyl vinyl ether, 3-trimethylsilyloxypropyl vinyl ether, 4-trimethylsilyloxybutyl vinyl ether, 2- Vinyl monomers containing a trialkylsilyloxy group, such as trimethylsilyloxyethyl methacrylate or 2-trimethylsilyloxyethyl acrylate; trialkylsilyloxy, such as vinyl 4-trimethylsilyloxycarbonylpentanoate, trimethylsilyl methacrylate or trimethylsilyl acrylate There are monomers containing a carbonyl group. Among these monomers, (meth) acrylic monomers have insufficient copolymerizability with fluoroolefins, so when these are used, they should be suppressed to an amount that does not lower the polymerization rate. preferable.

Specific examples of the monomers (c) copolymerizable with the monomers (a) and (b) include methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, and isobutyl vinyl ether. Alkyl vinyl ethers such as tert-butyl vinyl ether, n-pentyl vinyl ether, n-hexyl vinyl ether, n-octyl vinyl ether and 2-ethylhexyl vinyl ether; cycloalkyl vinyl ethers such as cyclopentyl vinyl ether, cyclohexyl vinyl ether or methylcyclohexyl vinyl ether; benzyl vinyl ether or Aralkyl vinyl ethers such as phenethyl vinyl ether; 2,2,3,3-tetrafluoropropyl vinyl ether 2,2,3,3,4,4,5,5-octafluoro-pentyl vinyl ether, 2,2,3,3,4,4,5,5,6,
(Per) fluoroalkyl such as 6,7,7,8,8,9,9-hexadecafluorononyl vinyl ether, perfluoromethyl vinyl ether, perfluoroethyl vinyl ether, perfluoropropyl vinyl ether, perfluorooctyl vinyl ether, perfluorocyclohexyl vinyl ether Vinyl ethers; vinyl acetate, isopropenyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caproate, vinyl versatate, vinyl laurate, vinyl stearate, vinyl benzoate, p-tert- Vinyl carboxylate esters such as vinyl butyl benzoate vinyl salicylate and vinyl cyclohexane carboxylate; furthermore, ethylene, vinyl chloride, vinylidene chloride, (meth) acrylonitrile, various (meth) Acrylic acid esters and the like are representative.

To obtain the fluoroolefin copolymer (A) or (D) from such monomers, the fluoroolefin (a) is 15 to 70% by weight, and the vinyl monomer (b) 1 having a reactive functional group To 30% by weight, copolymerizable monomers (c) 5 to 84% by weight, more preferably (a) 20 to 60% by weight.
% By weight, (b) 3 to 25% by weight, and (c) 10 to 77% by weight.

If the amount of the fluoroolefin (a) is less than 15% by weight, the weather resistance is insufficient, and if it exceeds 70% by weight, the solubility of the obtained copolymer in a solvent is reduced, and there is a problem in workability. Occurs. When the amount of the monomer (b) containing a reactive functional group is less than 1% by weight, the thinner resistance of the cured coating film is inferior, and when it exceeds 30% by weight, the obtained copolymer is dissolved in a solvent. This is not preferable because the curing property is reduced or the amount of the curing agent to be blended is increased to cause a decrease in weather resistance. Further, the amount of the copolymerizable monomer (c) is 5% by weight.
If the amount is less than the above, the solubility of the obtained copolymer in the solvent is lowered, and if it exceeds 84% by weight, the weather resistance of the cured coating film is undesirably reduced.

Among the copolymerizable monomers (c), alkyl vinyl ethers, cycloalkyl vinyl ethers and vinyl carboxylate esters are preferred from the viewpoint of increasing the polymerization rate during the preparation of the copolymer and the weather resistance of the coating film. It is particularly preferable to use at least one selected from the group consisting of

In preparing the fluoroolefin-based copolymer (A) or (D) from the above-mentioned monomers, a known and commonly used radical polymerization initiator is used as a polymerization initiator to be used. Representative examples include azo compounds such as azobisisobutyronitrile and azobisisovaleronitrile; t-butylperoxypivalate, t-butylperoxybenzoate, and t-butylperoxy-2-.
Ethyl hexanoate, benzoyl peroxide, lauroyl peroxide, acetyl peroxide, di-t-butyl peroxide, dicumyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate And the like.

The amount of the radical polymerization initiator used is appropriately determined depending on the type of the polymerization initiator, the polymerization temperature, the molecular weight of the copolymer, and the like, but generally, 0.01 to 10 of the total amount of the monomers to be copolymerized.
It may be about weight%.

In order to produce a fluoroolefin-based copolymer (A) or (D) containing a reactive functional group using each of the above monomer components, emulsion polymerization, suspension polymerization, bulk polymerization, solution polymerization, etc. Known polymerization methods can be applied, but bulk polymerization and solution polymerization are preferred, and furthermore, the obtained copolymer is used as it is as a curable resin composition such as a base resin component for a solution type paint. From the viewpoint of obtaining the solution, the solution polymerization method is particularly preferable. Representative solvents used for producing the copolymer by the solution polymerization method include aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene; n-pentane, n-hexane, and n-octane. Aliphatic hydrocarbons; aliphatic hydrocarbons such as cyclopentane, cyclohexane, methylcyclohexane, and ethylcyclohexane; methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, n-pentanol, Pentanol, n-hexanol, n-octanol, 2-ethylhexanol, cyclohexanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether Le, alcohols such as propylene glycol monoethyl ether;
Dimethoxyethane, tetrahydrofuran, dioxane,
Ethers such as diisopropyl ether and di-n-butyl ether; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, methyl amyl ketone, cyclohexanone and isophorone; methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate; Esters such as n-butyl acetate, isobutyl acetate, amyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate; chloroform, methylene chloride,
Chlorinated hydrocarbons such as carbon tetrachloride, trichloroethane and tetrachloroethane; furthermore, N-methylpyrrolidone;
Examples include dimethylformamide, dimethylacetamide, and ethylene carbonate. Such solvents may be used alone or as a mixture of two or more kinds, but it is preferable to select such solvents so as to dissolve the formed copolymer. And the amount used is 100 total monomers
It may be about 5 to 1000 parts by weight based on parts by weight.

Among the above-mentioned solvents, an isocyanate group as a reactive functional group, a trialkylsilyloxy group, a copolymer containing a trialkylsilyloxycarbonyl group is prepared, or a polyisocyanate compound as described below is blended as a curing agent. In such cases, it is desirable to avoid the use of alcohol solvents.

As a specific example of preparing the fluoroolefin-based copolymer (A) of the present invention by the method of (i), (i) the hydroxyl-containing copolymer prepared by the above-mentioned method is mixed with a polycarboxylic anhydride or a polyisocyanate compound. (Ii) a carboxyl group-containing copolymer prepared by the above-mentioned method is reacted with a monoepoxy compound, a polyisocyanate compound or an aziridine compound to form a hydroxyl group, respectively. ,
Introducing an isocyanate group or an amino group,
(Iii) an epoxy group-containing copolymer prepared by the method described above, which reacts with a primary amine compound or a secondary amine compound to introduce a secondary or tertiary amino group, and (iv) the method described above. A carboxylic acid anhydride-containing copolymer prepared by the method described above, wherein a compound having one active hydrogen-containing group and one tertiary amino group in each molecule is reacted to introduce a tertiary amino group, v)
Reacting a hydroxyl-containing copolymer prepared by the method of the above with a trialkylchlorosilane compound in the presence of a base to introduce a trialkylsilyloxy group, (v
a method in which a carboxyl group-containing fluoroolefin-based copolymer prepared by the method i) is reacted with a trialkylchlorosilane compound in the presence of a base to introduce a trialkylsilyloxycarbonyl group, and the like. .

Weight average molecular weight of the fluoroolefin copolymer (A) or (D) thus obtained (ら れ る)
Is 7,000-300,000, more preferably 10,000-250,00
It is 0. If ▼ is less than 7,000, the curability and stain resistance are poor, and the adhesion after exposure is undesirably reduced. When ▼ is more than 300,000, the viscosity of the paint becomes high, so that the coating workability and finish appearance deteriorate, and the pot life of the paint becomes extremely short, which is not preferable. The copolymer (A) or (D) has at least two reactive functional groups per molecule from the viewpoint of curability, and more preferably 3 reactive functional groups.
Those having from 60 to 60 are particularly preferred.

Next, curing agents (B) and (E) capable of reacting with the reactive functional groups constituting the colored coating [I] and the clear coating [II].
As typical examples, a polyisocyanate compound, a blocked polyisocyanate compound, an amino resin or a polycarboxylic anhydride compound is used when the reactive functional group is a hydroxyl group, and a polyisocyanate compound is used when the reactive functional group is a carboxyl group. Epoxy compounds, polyaziridine compounds polyisocyanate compounds or blocked polyisocyanate compounds, polyepoxy compounds when the reactive functional group is an amino group, compounds using an epoxy group and a hydrolyzable silyl group in one molecule, block polyisocyanate Isocyanate compound or polyisocyanate compound, if the reactive functional group is an epoxy group, polycarboxy compound, polycarboxylic anhydride compound, polyketimine compound or polyaldimine compound, the reactive functional group is a trialkylsilyloxy group Place A polyisocyanate compound, a blocked polyisocyanate compound, an amino resin or a polycarboxylic acid anhydride compound, and when the reactive functional group is a trialkylsilyloxycarbonyl compound, a polyepoxy compound, a polyaziridine compound, a polyisocyanate compound or a block. When the reactive functional group is an amide group, a polyisocyanate compound, an amino resin or a blocked polyisocyanate compound can be blended.

Further, when the reactive functional group is a trialkylsilyloxy group, the silyloxy group is hydrolyzed by moisture in the air to form a hydroxyl group after coating, and is cured by a curing agent capable of reacting with the hydroxyl group as described above. It is possible. Further, when the reactive functional group is a trialkylsilyloxycarbonyl group, the trialkylsilyloxycarbonyl group is hydrolyzed by moisture in the air after painting to generate a carboxyl group, and thus reacts with the carboxyl group as described above. The resulting curing agent can be blended and cured.

When the reactive functional group is a hydroxyl group, a carboxyl group, a trialkylsilyloxy group, or a trialkylsilyloxycarbonyl group, an alkoxide or complex compound of a metal such as aluminum, titanium, zirconium, or silicon is compounded as a curing agent. You can also.

Representative examples of the polyisocyanate compounds as the above-mentioned curing agents (B) and (E) include aliphatic diisocyanates such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate; and cycloaliphatic aliphatic acids such as xylylene diisocyanate and isophorone diisocyanate. Diisocyanates; or organic diisocyanates such as tolylene diisocyanate, aromatic diisocyanates such as 4,4'-diphenylmethane diisocyanate, or adducts of these organic diisoanates with polyhydric alcohols; and polymers or isocyanates of the organic diisocyanates. -A biuret compound or the like can be mentioned, but an aliphatic, alicyclic or aralkyl isocyanate compound is particularly preferred from the viewpoint of weather resistance. Examples of typical commercial products of such various polyisocyanate compounds include "Varnock, DN-950, -980,
-981 "(product of Dainippon Ink and Chemicals, Inc.)," Dismodule N "(product of Bayer AG, West Germany)," Takenate D-140N "(product of Takeda Pharmaceutical Co., Ltd.)," Coronate EH "[Japan Polyurethane Industry Co., Ltd.)
"Duranate 24A-90cx" (a product of Asahi Kasei Corporation) or a vinyl polymer containing an isocyanate group.

On the other hand, typical examples of the blocked polyisocyanate compound include those obtained by blocking various polyisocyanate compounds as described above with a known and commonly used blocking agent, and representative commercially available products of such blocked polyisocyanate compounds. For example, "Barnock B7-
671 "(product of Dainippon Ink and Chemicals, Inc.)," Takenate B-815-N "(product of Takeda Pharmaceutical Co., Ltd.)," ADDITOL VXL-80 "(Hoechst Gosei Co., Ltd.)
Product] or "Coronate 2507" (product of Nippon Polyurethane Industry Co., Ltd.), or a vinyl polymer having a blocked isocyanate group.

Specific examples of the polycarboxylic anhydride compound include trimellitic anhydride, pyromellitic anhydride, and vinyl polymers containing a carboxylic anhydride group.

Specific examples of the polyepoxy compound include ethylene glycol diglycidyl ether, glycerin polyglycidyl ether, sorbitol polyglycidyl ether, glycidyl phthalate, and a vinyl polymer containing an epoxy group.

Specific examples of the compound in which an epoxy group and a hydrolyzable silyl group are used in one molecule include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriisopropenyloxysilane or glycidyl methacrylate and γ-glycidoxypropyltrimethoxysilane. There is an acrylic copolymer containing methacryloxypropyltrimethoxysilane as an essential monomer component.

Representative aminoplasts include melamine,
Urea, acetoguanamine, benzoguanamine, or condensate obtained by reacting an amino group-containing compound component such as spiroguanamine with an aldehyde compound component such as formaldehyde, paraformaldehyde, acetaldehyde or glyoxal by a known and common method, or Examples thereof include those obtained by etherifying each of these condensates with an alcohol. Of course, any of those usually used for paints can be used.

Among them, those partially or completely etherified with alcohols of C _{1 to} C ₄ are preferable. Specific examples of such aminoplasts include hexamethyl etherified methylol melamine, hexabutyl etherified methylol melamine, and methyl butyl mixed. Etherified methylol melamine, methyl etherified methylol melamine,
Examples thereof include butyl etherified methylol melamine, iso-butyl etherified methylol melamine, and condensates thereof.

Specific examples of the polyaziridine compound, the molar ratio of ethylene glycol diacrylate and ethylene imine 1: 2
Adducts, adducts of trimethylolpropane triacrylate and ethyleneimine at a molar ratio of 1: 3, and vinyl polymers containing an aziridinyl group are exemplified.

Next, typical examples of the coloring material (C) used in preparing the coloring paint [I] used in the present invention include organic blacks such as carbon black, phthalocyanine blue, phthalocyanine green, and quinacridone red. Pigment, titanium oxide, iron oxide, titanium-barium-nickel composite oxide, titanium-antimony-chromium composite oxide, titanium-cobalt-nickel-zinc composite oxide,
Inorganic pigments such as a cobalt-aluminum composite oxide, a copper-chromium composite oxide, barium sulfate, potassium carbonate, talc, and barium carbonate are exemplified. These may be used alone or in combination of two or more. These coloring materials (C) are used from the viewpoint of imparting aesthetic properties and preventing the adhesion of the coating film from being reduced with time due to exposure.

The coloring paint used in the present invention is a solution type, and is a fluoroolefin copolymer (A) and a curing agent (B).
Is used completely or mostly in a state of being dissolved in an organic solvent. Typical solvents used for this purpose include the various solvents described above used in preparing a fluoroolefin-based copolymer.

In preparing the colored coating [I] in the present invention,
Known additives such as a leveling agent, an anti-separation agent, a pigment dispersant, a curing catalyst as described above, an antioxidant and an ultraviolet absorber as described later can be added.

In order to prepare the coloring paint [I] from the above-mentioned respective components, a mixture comprising the fluoroolefin-based copolymer (A), the coloring material (C) and the solvent is used by using a pigment disperser such as a sand mill. After the coloring base is prepared by the above method, a curing agent may be blended.

Next, the clear paint [II] used in the present invention will be described.

The fluoroolefin-based copolymer (D) constituting the clear coating material [II] of the present invention contains various fluoroolefin units as essential constituents, as described above, similar to the fluoroolefin-based copolymer (A), Further, it is a copolymer containing on average at least two reactive functional groups in one molecule as described above, and is soluble in known and commonly used solvents.

Specific examples of the fluoroolefin-based copolymer (D) are as described above.

Further, it has already been described that the curing agent (E) constituting the clear coating material [II] used in the present invention is the same as the curing agent (B) constituting the colored coating material [I].

The ultraviolet absorber (F) constituting the clear paint [II] used in the present invention is not particularly limited as long as it has compatibility with both components (D) and (E).
A typical example is 2- (2'-hydroxy-
5'-methylphenyl) benzotriazole, 2-
(2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2-
(2'-hydroxy-4'-n-octoxyphenyl)
Benzotriazole, 2- [2'-hydroxy-3 ',
5'-bis (α, α-dimethylbenzyl) phenyl] -2
H-benzotriazole, 2- (2'-hydroxy-
5'-t-octylphenyl) benzotriazole, 2
-(3 ', 5'-di-tert-butyl-2'-hydroxyphenyl) benzotriazole, 2 (3'-tert-butyl-
5'-methyl-2'-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3 ', 5'-di-t-amyl-2'-hydroxyphenyl) benzotriazole,
2- (2'-hydroxy-5'-t-butylphenyl)
Benzotriazole compounds such as benzotriazole and 2- (2 ', 4'-hydroxyphenyl) benzotriazole; 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, and 2,2'-dihydroxy-4-methoxy Benzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-octadecyl Oxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 4-decyloxy-2-hydroxybenzophenone, 2-hydroxy-4-benzoxybenzophenone,
Benzophenone-based compounds such as -hydroxy-4-methoxy-2'-carboxybenzophenone; phenyl salicylate, p-octylphenyl salicylate, p-
salicylic acid ester compounds such as t-butylphenyl salicylate; N- (2-ethoxyphenyl) -N'-
(4-isododecylphenyl) ethanediamide, N-
Oxalylanilide-based compounds such as (2-ethoxyphenyl) -N '-(2-ethyl) ethanediamide; 2-cyano-3,3-diphenylacrylate octyl, 2-cyano-
Ethyl 3,3-diphenylacrylate, 2-cyano-3-
Phenyl-3 (3,4-dimethylphenyl) acrylic acid 2
Such as -ethylhexyl, 2-ethylhexyl 2-cyano-3- (p-methoxyphenyl) -3- (3,4-dimethylphenyl) acrylate, p-methoxy-α- (3,4-xylyl) benzylidenemalononitrile Unsaturated nitrile compounds; other resorcinol monobenzoates,
2,4-di-t-butylphenyl-3 ', 5'-di-t-butyl-4-hydroxybenzoate, [2,2-thiobis (4-t-octylphenolate)]-n-butylamine-nickel (II) complexes and nickel dibutyl dithiocarbonate. Among the ultraviolet absorbers as described above,
It is particularly preferable to use a benzotriazole-based compound or a hydroxybenzophenone-based compound from the viewpoint of improving the durability.

In order to obtain the clear coating material [II] from the components (D), (E) and (F), 1 to 100 parts by weight of the component (E) is used with respect to 100 parts by weight of the component (D). And more preferably 2 to 70 parts by weight, and 0.1 to 20 parts by weight of the component (F) based on 100 parts by weight of the total of both the components (D) and (E).
More preferably, 0.3 to 15 parts by weight may be blended.

In the present invention, the durability can be further improved by further adding an antioxidant to the clear paint [I]. Such antioxidants include:
There is no particular limitation as long as it is compatible with the component (D) and the component (E).
Methylene bis- (2,6-di-t-butylphenol),
2,2'-methylenebis- (4-methyl-6-t-butylphenol), 1,3,5-trimethyl-2,4,6-tris (3,
5-di-t-butyl-4-hydroxybenzyl) benzene, 1,1,3-tris- (2-methyl-5-t-butyl-
4-hydroxyphenyl) propane, 2,2'-ethylidenebis- (4,6-di-t-butylphenol), triethylene glycol-bis-3- (3-t-butyl-4-
(Hydroxy-5-methylphenyl) propionate, 3
-(3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) octadecyl propionate, 2,2'-methylenebis (4-ethyl-6-tert-butylphenol), pentaerythrityl-tetrakis- [3 -(3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,
6-di-t-butyl-4-methylphenol, 4,4'-butylidenebis- (3-methyl-6-t-butylphenol), 1,6-hexanediolbis-3- (3 ', 5'-
Hindered phenolic compounds such as di-t-butyl-4'-hydroxyphenyl) propionate;
2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis (2,2,6,6-tetramethyl-4-piperidyl)
Sebacate, 1- [2- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-t-butyl-4- (Hydroxyphenyl) propionyloxy] -2,2,6,6-tetramethylpiperidine, 8-benzyl-7,7,9,9-tetramethyl-3-octyl-1,3,8-triazaspiro [4,5]
Undecane-2,4-dione, 4-benzoyloxy-2,
Hindered amine compounds such as 2,6,6-tetramethylpiperidine; dilaurylthiodipropionate, distearylthiodipropionate, pentaerythritol-tetrakis- (3-laurylthiopropionate, dimyristylthiodipropionate) Among these antioxidants, a hindered amine compound or a hindered phenol compound is particularly preferable from the viewpoint of the effect of improving durability.

When such an antioxidant is added, (D), (E)
It is sufficient to add about 0.1 to 10 parts by weight based on 100 parts by weight in total.

Further, the clear coating material [II] used in the present invention may contain a leveling agent, a curing catalyst and other known and commonly used additives.

The cement-based substrate to which the coating method of the present invention is applied includes various bases prepared using a cement-based material such as concrete, asbestos slate, mortar, calcium silicate plate, ALC plate, and gypsum / slag-based material as essential components. Materials.

In the coating method of the present invention, such a cement-based substrate or a cement-based substrate on which an organic coating film is formed in advance,
A color paint (I) based on a solution-type fluoroolefin copolymer as a color paint is applied by a known and common method such as spray coating, roller coating, brush coating, and the like.
The topcoat may be applied as it is undried, or dried at room temperature, or dried by heating at a temperature of about 60 to 250 ° C., and then the solution-type clear coating as a topcoat (I
I] may be applied by a known and commonly used method as described above.

In the coating method of the present invention, when using a base material that easily oozes out an alkali component, an undercoat paint such as a sealer is used in advance to prevent oozing of the alkali component or to improve the adhesion to the base material. It is particularly preferable to form an organic coating film by painting. Representative examples of such undercoat paints include acrylic lacquer paints and acrylic paints.
Various acrylic solution-type paints such as urethane paints, acrylic-epoxy paints, acrylic-melamine paints,
Acrylic emulsion paints, lacquer paints mainly composed of chlorinated polyolefins such as chlorinated polyethylene or chlorinated polypropylene, moisture-curable urethane resin paints and various epoxy resin paints are available.

After the top coat is applied as described above, the top coat may be cured at room temperature depending on the type of the curing agent to cure (in some cases simultaneously with the solution type acrylic resin-based colored coating), Forced drying or baking may be performed at a temperature of about 250 ° C.

〔Example〕

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, “parts” are based on weight.

(I) Fluoroolefin-based copolymer (A) and (D) Solution V-1 of a polymer having the composition and properties as shown in Table 1 as the fluoroolefin-based copolymer (A) and (D) component ~ V-5 was used.

(Ii) Preparation of Colored Paint [I] A glass bead was prepared by mixing a mixture of the fluoroolefin-based copolymer, colorant, and curing catalyst and other additives shown in Table 1 in the ratio shown in Table 2. Was dispersed using a sand mill for 1 hour, and a curing agent was added at the ratio shown in Table 2, and toluene / xylene / butyl acetate / cellosolve acetate = 30/30/30/10 (weight ratio) The resulting mixture was diluted with a mixed solvent to a viscosity allowing air spraying to prepare coloring paints I-1 to I-7.

(Iii) Preparation of clear paint [II] The fluoroolefin-based copolymer, ultraviolet absorber, antioxidant, curing agent and curing catalyst shown in Table 1 were mixed in the proportions shown in Table 3, and toluene was further added. / Xylene / Butyl acetate / Cellosolve acetate = 30/30/30/10 (weight ratio) was diluted to a viscosity allowing air spraying with a mixed solvent to prepare clear paints II-1 to II-7.

The above-mentioned colored paint [I] was air-sprayed on various cement-based substrates shown in Table 4 or a cement-based substrate on which an organic-based coating film was previously formed, and dried under the conditions shown in Table 4. , Air spray the clear coating [II],
The composition was cured under the conditions shown in Table 4 to obtain a coated product.

The coated material thus obtained was subjected to a Dupanel light control weatherometer (accelerated weathering tester manufactured by Suga Test Instruments Co., Ltd., test conditions: UV irradiation 70 ° C.-8 hours, condensation 50 ° C.-4)
The exposure was repeated for 6000 hours with the time being one cycle, and the gloss and color change were examined.

Further, the coated article after the exposure was subjected to the following heating / cooling repetition test for 10 cycles, and the state change of the coating film was examined.
The results are shown in Table 5.

<Hot and cold repeated test> Comparative Example 1 A concrete plate coated with a colored coating I-2 as a top coat was prepared in the same manner as in Example 2 except that the clear coating II-2 was not applied. This panel was subjected to the same accelerated weathering test as in the example, and after exposure for 6000 hours, the gloss retention was 25% and significant choking was observed.

Comparative Example 2 A colored concrete I-1 was applied as a top coat in the same manner as in Example 6 except that the clear paint II-5 was not applied, followed by drying at 25 ° C. for 10 days to prepare a painted concrete plate. This panel was subjected to the same accelerated weathering test as in the example, and after 6,000 hours of exposure, the gloss retention decreased to 40%.

Comparative Example 3 A slate plate coated with a colored coating I-7 as a top coat was prepared in the same manner as in Example 9 except that the clear coating II-7 was not applied. This panel was subjected to the same accelerated weathering test as in the example, and exposed for 6,000 hours.
The gloss retention was 25%, and significant choking was observed.

Comparative Example 4 A colored paint I-4 was applied as a top coat in the same manner as in Example 4 except that the clear paint II-4 was not applied, followed by baking at 80 ° C. for 30 minutes to obtain a painted concrete plate.
After the panel was left at room temperature for 10 days, it was subjected to the same accelerated weathering test as in the example, and was exposed for 6000 hours. As a result, the gloss retention decreased to 35%. The color difference ΔE was 11.5.

[Effects of the Invention] The coating method of the cement-based substrate of the present invention, that is, a cement-based substrate or a cement-based substrate on which an organic-based coating film is formed in advance, a fluoroolefin-based copolymer as a base coat, a curing agent, and By applying a color paint containing a colorant and then applying a clear paint containing a fluoroolefin copolymer, a curing agent and an ultraviolet absorber as a top coat, it is extremely durable on a cement base material. And a coating film excellent in cosmetics can be formed.

Therefore, the coating method of the present invention is applied to various types of cement-based substrates, and can improve the aesthetic appearance and durability of the cement-based substrates over a long period of time.

Claims (11)

(57) [Claims] 1. A fluoroolefin copolymer (A) which is soluble in a solvent containing at least two reactive functional groups per molecule as a base coat on a cement-based substrate, and which is capable of reacting with said reactive functional group. After applying a solution-type coloring paint [I] containing the agent (B) and the coloring material (C) as essential components and curing it as required, at least two reactive resins per molecule are used as a top coat. A fluoroolefin-based copolymer (D) soluble in a solvent containing a functional group,
A cement-based base, which is cured by applying a solution-type clear paint [II] comprising as essential components a curing agent (E) and an ultraviolet absorber (F) capable of reacting with the reactive functional group. How to paint the material. 2. A fluoroolefin-based copolymer (A) which is soluble in a solvent containing at least two reactive functional groups per molecule as a base coat on a cement-based substrate on which an organic coating has been formed in advance. After applying a coloring paint [I] containing a curing agent (B) and a coloring material (C) which are capable of reacting with a reactive functional group as essential components and curing it as necessary, a top coat per molecule is obtained. Essential components include a fluoroolefin-based copolymer (D) soluble in a solvent containing at least two reactive functional groups, a curing agent (E) capable of reacting with the reactive functional groups, and an ultraviolet absorber (F). A method for coating a cement-based substrate, characterized by applying and curing a clear paint [II] comprising: 3. The fluoroolefin-based copolymer (A)
Or (D) is (a) 15 to 70% by weight of a fluoroolefin, and (b) 1 to 5 vinyl monomers having a reactive functional group.
3. The coating method according to claim 1, wherein 30 parts by weight and (c) 5 to 84 parts by weight of another copolymerizable monomer are copolymerized. 4. The fluoroolefin (a) is selected from the group consisting of tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, vinyldene fluoride, vinyl fluoride, and (per) fluoroalkyl trifluorovinyl ether (provided that the number of carbon atoms of the alkyl group is The coating method according to claim 3, wherein the coating method is at least one selected from the group consisting of (1) to (18). 5. The reactive functional group is at least one selected from the group consisting of a hydroxyl group, a carboxyl group, an amino group, an epoxy group, an amide group, an isocyanate group, a carboxylic anhydride group, a silyloxy group and a silyloxycarbonyl group. The coating method according to claim 1. 6. The coating method according to claim 3, wherein the other copolymerizable monomer (c) is at least one selected from the group consisting of alkyl vinyl ethers, cycloalkyl vinyl ethers, and carboxylic acid vinyl esters. 7. The fluoroolefin-based copolymer (A)
3. The coating method according to claim 1, wherein the weight average molecular weight of (D) is from 7,000 to 300,000. 8. The curing agent (B) or (E) comprises a polyisocyanate compound, a blocked polyisocyanate compound, an amino resin, a polyepoxy compound or a compound having both an epoxy group and a hydrolyzable silyl group in one molecule. The coating method according to claim 1, wherein the coating method is at least one selected from the group consisting of: 9. The coating method according to claim 1, wherein the ultraviolet absorber (F) is a benzotriazole compound. 10. The coating method according to claim 1, wherein the ultraviolet absorbent (F) is a hydroxybenzophenone compound. 11. The coating method according to claim 1, wherein the clear paint (II) contains an antioxidant.