JPH0463836B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention makes it possible to coat the surface of an uncured cement product with an uneven surface with a paint having excellent film performance without sagging or cracking, and shortens the construction period. , relates to a method for producing cement products with excellent long-term durability. <Prior art and problems> Building materials using cement products such as mortar, concrete, and slate are often used for exterior materials, block walls, and the like. Such cement products are usually coated with paint to give them an aesthetic appearance, and as the lifespan of buildings is extended, highly durable finishes are required, and with the mass production of building materials, paint finishes are becoming more and more popular. There is a growing demand for speed. However, a coating composition that satisfies these requirements has not yet been developed. In other words, conventional painting on uncured cement products has the disadvantage that coating defects such as peeling and discoloration may occur if the paint is not applied after the product has been left for a period of time or two to adjust the pH and moisture content of the surface of the cement product. It was hot. Furthermore, in order to prevent efflorescence and add durability, a top coat such as a solvent-based paint or a water-based paint may be applied, but if the time before applying the top coat is not selected appropriately, efflorescence can be prevented. Furthermore, since the undercoat film lacks solvent resistance, there are drawbacks such as reduced gloss and wrinkles in the paint film. In addition, recently, in order to impart flexibility to cement products, products having wavy or random uneven patterns formed on the surface of the products have become widely used. If a thick film of paint is applied to a cement product with such an uneven surface, the paint will sag and accumulate in the recesses, resulting in a thicker film than necessary, and conversely, the convex parts will become a thin film, making it difficult to form a uniform seam. This is difficult, and therefore has drawbacks such as the uneven shape of the surface of the cement product is impaired, shape retention is poor, and the coating film is cracked. In view of the above-mentioned prior art, the present invention is a method for producing cement products that can be coated with a paint that does not have the above-mentioned drawbacks and has excellent film performance, shortens the construction period, and has excellent long-term durability. The purpose is to provide the following. <Means for solving the problem> This purpose is to apply a copolymer emulsion resin of an alkyl ester of acrylic acid or methacrylic acid (a) to the surface of an uncured cement product having an uneven surface. Alkyl group has 1 to 8 carbon atoms) Solid content
...2 to 15% by weight () Bisphenol type epoxy emulsion resin solid content ...1 to 5% by weight () Hollow inorganic powder with average particle size of 30 to 300μ
...10 to 40% by weight () Cement ...20 to 60% by weight () 0.8 to 1.2 equivalents of polyamide resin or aliphatic polyvalent amine curing agent of the bisphenol type epoxy emulsion resin, and further filler if necessary, consisting of additives, and [()
An aqueous coating composition having a viscosity of 50 to 500 poise consisting of 100 parts by weight of a mixture having a weight ratio of +()]/() in the range of 0.15 to 0.28 and (b) 15 to 70 parts by weight of water is applied. A method for manufacturing a cement product having an uneven surface, characterized by curing and curing the cement product and the paint film at the same time, and then applying a top coat with a material containing a fluorine-containing copolymer having a hydroxyl group and a polyisocyanate compound as main components. This is achieved by With the method of the present invention, uncured cement products with uneven surfaces can be immediately coated, making it possible to apply on a factory line, reducing construction time, and creating a thick film without sagging or cracking at room temperature or forced drying. It is possible to obtain a coating film that can be painted, has good shape retention on the uneven surface, and has excellent long-term durability, adhesion, and alkali resistance. The present invention will be described in detail below. First, the aqueous coating composition used in the present invention will be explained. The alkyl group of the alkyl ester monomer having 1 to 8 carbon atoms of acrylic acid and the alkyl ester monomer having 1 to 8 carbon atoms of methacrylic acid, which are components of the copolymerized emulsion resin () of alkali acid or methacrylic acid alkyl ester, is Methyl, ethyl, n-butyl, isobutyl, tert-butyl, 2-ethylhexyl, benzyl,
Propyl, isopropyl, sec-butyl, etc. are typically used. Alkyl groups having 9 or more carbon atoms may generate a gel during emulsion polymerization, or the emulsion particles may become highly hydrophobic, making them unsuitable for the synthesis of emulsion resins for cement admixture. or,
For these acrylic acid (or methacrylic acid) alkyl esters, copolymer emulsion resins containing up to 30% by weight of styrene may be used. However, if styrene is used in an amount of 30% by weight or more, the weather resistance of the resulting emulsion coating film will be significantly reduced, making it undesirable for use as an outdoor emulsion resin that requires durability. Particularly preferred acrylic acid or acrylic methacrylate esters include methyl methacrylate, ethyl acrylate, butyl acrylate, and 2-acrylic acid.
-ethylhexyl, and if necessary, it is also possible to copolymerize several weight percent of a functional group monomer such as acrylic acid, methacrylic acid, or 2-hydroxyethyl methacrylate. Since the copolymerized emulsion resin of acrylic acid (or methacrylic acid) alkyl ester used in the present invention is mixed with cement, it is preferable to have alkali resistance and excellent cement mixing stability. Nonionic surfactants are suitable as emulsifiers. Advantageously, these acrylic emulsion resins have a molecular weight of 50,000 to 300,000, preferably 100,000 to 200,000. Further, the minimum film forming temperature is preferably 5° C. or lower; if it is higher than that, cracks are likely to occur during film forming. In addition, acrylic emulsion resin has a solid content of 40
The viscosity in weight percent is preferably 100 cps or less. If it exceeds that range, it is necessary to increase the amount of water to lower the viscosity, which lowers the solids content and makes the coating film more likely to crack due to fading during drying. These resins are blended in the mixture (a) at a solid content of 2 to 15% by weight. If the resin content is less than 2% by weight, the initial hardness and weather resistance of the coating film will decrease, and efflorescence will likely occur. On the other hand, if the resin content exceeds 15% by weight, thick film coating (approximately 0.5 to 10 mm)
It is not possible to do so, and cracks are more likely to occur. The bisphenol type epoxy emulsion resin () is made by using an emulsifier to make a resin of aromatic diglycidyl ethers obtained from bisphenol A and epichlorohydrin and having an average molecular weight of 350 to 1000 into a water-dispersed type. The solid content used in the mixture (a) is 1 to 5% by weight. If the resin content is less than 1% by weight, the adhesion to the substrate will be reduced, and if it exceeds 5% by weight, the weather resistance of the formed coating film will be significantly reduced. Hollow inorganic powder () is a powder that is completely hollow inside and the hollow part is completely closed with a shell.
It is a powder in the form of closed or open cells with partition walls inside, similar to pumice, and its average particle size is 30~30.
A thickness of about 300μ is appropriate. When the average particle size is less than 30μ, cracking tends to occur and the strength of the coating film decreases, while when it exceeds 300μ, it tends to sag, and the coating film lacks smoothness, resulting in poor appearance. Examples of hollow inorganic powder include glass balloons,
Shirasu balloon, aluminosilicate balloon,
Typical examples include silica balloons, alumina balloons, zirconia balloons, and carbon balloons. Particularly from the viewpoint of coating film strength, it is desirable that the hydrostatic pressure at 50% break is 10 Kg/cm ² or more, and specific examples include glass balloons, aluminosilicate balloons, alumina balloons, and zirconia balloons. This hollow inorganic powder is blended to obtain coatings without sagging or cracking even in thick coatings, to improve brittleness, and to increase weight.
Furthermore, it has the effect of reducing the specific gravity of the coating composition and improving coating workability. In addition, ordinary pigments,
Fillers such as aggregate alone cannot prevent sagging and cracking when a thick film is applied to a cement product with an uneven surface. The hollow inorganic powder is blended in the mixture (a) at a ratio of 10 to 40% by weight, and the above effects can be obtained within this range. Examples of the cement include Portland cement, blast furnace cement, silica cement, alumina cement, etc., but the type thereof is not particularly limited. In the present invention, the cement is the above-mentioned mixture.
It is blended in (a) in a proportion of 20 to 60% by weight.
If the cement content is less than 20% by weight, cracking is likely to occur during pressure film, and adhesion is reduced. On the other hand, if it exceeds 60% by weight, the coating film becomes brittle and efflorescence is likely to occur. As the curing agent for epoxy resins, polyamide resins obtained by polycondensation of diamines or diamine derivatives with dibasic acids or dibasic acid derivatives, or resin group polyvalent amines such as ethylenediamine, diethylenetriamine, triethylenetetramine, etc. Alternatively, aliphatic polyvalent amines modified with phenol resins, epoxy resins, etc. are suitable. The amount of curing agent used is 0.8 to 1.2 of the epoxy group of the epoxy resin.
It is necessary to use equivalent amounts. If the amount is less than 0.8 equivalents or more than 1.2 equivalents, the original properties of the epoxy resin, such as adhesion and flexibility, will be significantly reduced, and other performances such as durability will also be deteriorated, which is undesirable. Additives for the aqueous coating composition used in the present invention include, for example, dispersants for improving pigment dispersibility, coating workability, storage stability, etc.
Examples include antifoaming agents, thickeners, preservatives, antifungal agents, and film-forming aids for improving the film-forming properties of coatings. In addition, various coloring pigments are used for coloring, extender pigments such as calcium carbonate, barium sulfate, talc, clay, etc. are used to improve the brittleness of the coating film, and particle size of silica sand, etc.
Add filler such as aggregate of 300 μ or less to the above mixture (a)
It is also possible to incorporate it within the range of 40% by weight or less. The weight ratio of the sum of the solid content of () copolymerized emulsion resin of acrylic acid (or methacrylic acid) alkyl ester and the solid content of () epoxy emulsion resin in the above mixture (a) and () cement is [( )+()]/()=0.15 to 0.28.
If this ratio is less than 0.15, the initial hardness of the coating film will not be achieved and efflorescence will occur, making it impossible to form a pressure film with good coating performance.On the other hand, if this ratio is greater than 0.28 In some cases, when the film is thick, cracks tend to occur. Said [()+()]/[()+()+()
The weight ratio of
is preferred. The aqueous coating composition of the present invention comprises 100% of the above mixture (a)
The viscosity of the aqueous coating composition is 50 to 500 poise by blending 15 to 70 parts by weight of water. This is because, within this range, cement hardenability and painting workability are good. 15 to 70 parts by weight of water (b) are added to the coating composition of the invention. If the amount of water is less than 15 parts by weight, the emulsion will tend to coagulate when mixed with cement, while if it exceeds 70 parts by weight, the solid content will decrease and the emulsion will become loose and crack when drying. The present inventors used vinyl acetate emulsion resins such as vinyl acetate resin, vinyl acetate-acrylic resin, ethylene-vinyl acetate resin, styrene-butadiene emulsion resins, etc. as the emulsion resins that are the components () and () above. We also investigated emulsion resins that are typically used in the paint industry, but for example, the former has poor weather resistance, alkali resistance, and long-term durability, and the latter has poor weather resistance. was found to be inappropriate. Next, the top coating used in the present invention will be explained. The top coating is a two-component coating whose main components are a fluorine-containing copolymer having hydroxyl groups and a polyisocyanate compound. As the fluorine-containing copolymer having a hydroxyl group (hereinafter referred to as "fluorine-containing copolymer" for convenience), a fluorine-containing copolymer having a hydroxyl group and having fluoroolefin and cyclohexyl vinyl ether as constituent components is desirable. In particular, the copolymer described in JP-A No. 57-34107 is preferred because it not only has long-term weather resistance but also has extremely low moisture permeability and can be cured at room temperature or by baking at a low temperature. It can be used for That is, the copolymer that can be suitably used in the present invention contains fluoroolefin, cyclohexyl vinyl ether, alkyl vinyl ether, and hydroxyalkyl vinyl ether as essential components, and has a content of 40 to 60 mol % and 5 mol %, respectively.
~45 mol%, 5-45 mol% and 3-15 mol%, preferably 45-55 mol%, 10-30 respectively
mol%, 10 to 35 mol% and 5 to 13 mol%, with a weight average molecular weight of about 1 to 10
10,000 is appropriate. Incidentally, if the fluoroolefin content is too low, the weather resistance will deteriorate, and if the fluoroolefin content is too high, there will be difficulties in manufacturing. Furthermore, if the cyclohexyl vinyl ether content is too low, the hardness of the coating film will decrease, and if the alkyl vinyl ether content is too low, the flexibility will decrease. In addition, if the hydroxyalkyl vinyl ether content is too low, the mechanical strength and adhesion of the coating film will decrease, while if it is too high, the solubility of the copolymer will change and it will only work with certain solvents such as alcohols. It is not preferable because it becomes insoluble and its applicability as a solvent-based paint base is restricted. In the fluorine-containing copolymer, the fluoroolefin is preferably perhaloolefin, particularly chlorotrifluoroethylene or tetrafluoroethylene. Further, as the alkyl vinyl ether, those containing a linear or branched alkyl group having 2 to 8 carbon atoms, particularly those in which the alkyl group has 2 to 4 carbon atoms, are suitable. Further, the fluorine-containing copolymer may contain comonomers other than the four essential components in an amount not exceeding 30 mol%. Such comonomers include olefins such as ethylene, propylene, and isobutylene; haloolefins such as beer chloride and vinylidene chloride; unsaturated carboxylic acid esters such as methyl methacrylate; vinyl acetate, vinyl n-butyrate, etc. Vinyl carboxylates; unsaturated caronic acids such as fumaric acid, maleic acid, acrylic acid, and methacrylic acid; The above-mentioned fluorine-containing copolymer is produced by causing a copolymerization reaction by causing a polymerization initiator or a polymerization initiation source such as ionizing radiation to act on a monomer mixture of a predetermined ratio in the presence or absence of a polymerization medium. Manufactured by. As such fluorine-containing copolymers, Lumiflon LF100, Lumiflon LF200, Lumiflon
LF210, Lumiflon LF300, Lumiflon LF400,
Lumiflon LF510, Lumiflon LF700 (both brand names manufactured by Asahi Glass Co., Ltd.), etc. are commercially available. Further, polyisocyanate is a compound having two or more isocyanate groups in one molecule, and is used as a curing agent. Examples of the polyisocyanate include hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, 4,4'-
methylene bis(cyclohexyl isocyanate),
Aliphatic or aliphatic diisocyanates, such as hydrogenated diphenylene diisocyanate and hydrogenated xylylene diisocyanate, or their biuret forms, dimers, trimers, or excess of these isocyanate compounds, and ethylene glycol, glycerin, and trimethylolpropane. Typical examples include reaction products with low-molecular-weight polyols such as , pentaerythritol, and the like. The room-temperature-curable top coating used in the present invention combines the above-described fluorine-containing copolymer and polyisocyanate in an equivalent ratio of isocyanate groups in the polyisocyanate to hydroxyl groups in the fluorine-containing copolymer (NCO/ The main component is a mixture of OH) in a ratio of [(0.8 to 1.6)/1], and to this, xylene, toluene, ethyl acetate, butyl acetate,
Methyl ethyl ketone, methyl isobutyl ketone,
Formulated with various organic solvents commonly used for paints such as n-heptane, n-hexane, and ethylene glycol monoethyl ether acetate, as well as various coloring pigments, extender pigments, additives, etc. as necessary. It is what it is. In the present invention, the top coat can be applied directly onto the cured coating film of the aqueous coating composition, but a primer may be interposed as necessary to further improve the adhesion of the top coat. As the primer, a two-component epoxy resin paint whose main components are an epoxy resin synthesized by a condensation reaction of bisphenol A and epichlorohydrin and a curing agent for the epoxy resin can be suitably used. Commercially available epoxy resins include Epikote #815, #823, %1001 (all product names manufactured by Ciel Chemical Co., Ltd.), and Epitote DTY-11×70.
{Product name manufactured by Toto Kasei Co., Ltd.), Adekal Resin EP-5100
-75X, EP-4200 (all product names manufactured by Asahi Denka Industries, Ltd.), Sumiepoxy ESA-011, ELA-115 (all product names manufactured by Sumitomo Chemical Industries, Ltd.), Araldite
6071, GY252 (all product names manufactured by Ciba Geigy), etc. Further, as the curing agent, ordinary polyamide resins, aliphatic polyvalent amines, or those modified with phenol resins, epoxy resins, etc. can be used. The amount of curing agent used is preferably 0.8 to 1.2 equivalents of the epoxy groups in the epoxy resin. Two-component epoxy resin paints are made by blending these with high-quality organic solvents and, if necessary, various coloring pigments, extender pigments, additives, and the like. Next, the method for manufacturing the cement product of the present invention will be explained. The above-mentioned water-based coating composition can be applied to a cement product with an uneven surface immediately after press molding and a cement product with an uncured uneven surface that has been primarily cured for demolding using a conventional coating method, such as spray coating, roller coating, or flow coating. Paint to a film thickness of approximately 0.5 to 10 mm. In the method of the invention, the coated substrate is then cured and cured. Examples of curing methods include the following methods, and any one or a combination of these methods may be used. (1) Natural curing (natural curing in atmospheric atmosphere), (2) Underwater curing (temperature 5~
(3) Steam curing (temperature 40-60℃)
℃ and humidity of 95 to 100% for 2 hours or more, followed by natural curing or autoclave curing as necessary). Pretreatments for these curing methods in the method of the present invention include the following. (1) A method of applying an aqueous coating composition to an uncured cement product, drying it to the touch, heating and drying it in an atmosphere of 60 to 100°C for 5 to 60 minutes, and subjecting it to the above-mentioned natural curing, water curing, or steam curing. (2) A method in which an acetic acid coating composition is applied to an uncured cement product, left to stand for 1 to 3 hours in an atmosphere of 30 to 50°C, and then subjected to the above-mentioned natural curing, water curing, or steam curing. (3) A method in which a vinegar-based coating composition is applied to an uncured cement product, left in the atmosphere for 3 hours or more, and then cured in water or in steam. In this way, the coating film of the cement product and the aqueous coating composition is cured and cured, and then, if necessary, a primer is applied to a dry film thickness of approximately 10 to 20 μm. After drying, a top coat is applied to a dry film thickness of approximately 15 μm. Paint by spray painting, roller painting, brush painting, etc. to a thickness of ~70μ and dry at room temperature or force dry at a temperature of 100℃ or less. <Effects of the Invention> Immediately applying an aqueous coating composition to an uncured cement product having an uneven surface by the method of the present invention,
Since it is cured and cured at the same time, it can be painted on a factory line, reducing construction time. Furthermore, by the method of the present invention, it is possible to apply a thick film without causing sagging, cracking, etc. and therefore without damaging the shape of the uneven surface, and it has long-term durability.
A coating film with excellent adhesion and alkali resistance can be obtained. <Examples> The present invention will be described in more detail below with reference to Examples. In addition, "part" and "%" indicate a weight basis. <Preparation of fluorine-containing copolymer solution> () Preparation of fluorine-containing copolymer solution (a) Tetrafluoroethylene 50 mol%, cyclohexyl vinyl ether 25 mol%, ethyl vinyl ether 12 mol%, hydroxybutyl vinyl ether 13 mol% A 50% xylene solution of a fluorine-containing copolymer (Tg 45°C, hydroxyl value 68) was prepared by polymerizing the monomer consisting of
[Hereinafter referred to as fluorine-containing copolymer solution (a)] () Preparation of fluorine-containing copolymer solution (b) Chlorotrifluoroethylene 52 mol%, cyclohexyl vinyl ether 17 mol%, ethyl vinyl ether 22 mol%, hydroxybutyl A monomer consisting of 9 mol % of vinyl ether was polymerized according to the method described in JP-A-57-34107 to prepare a 50% xylene solution of a fluorine-containing copolymer (Tg 35, hydroxyl value 40).
[Hereinafter referred to as fluorine-containing copolymer solution (b)] <Preparation of top coat> () Preparation of top coat (A) 100 parts of fluorine-containing copolymer solution (a), xylene
Trimer of base ingredient consisting of 10 parts and hexamethylene diisocyanate ["Coronate EH"]
(trade name manufactured by Nippon Polyurethane Co., Ltd.)] and a curing agent component consisting of 12 parts of butyl acetate were mixed immediately before painting to prepare a top paint. [Hereinafter referred to as top coat (A)] () Preparation of top coat (B) 100 parts of fluorine-containing copolymer solution (a), xylene
Main ingredient consisting of 10 parts and "Coronate EH"
A curing agent component consisting of 7 parts and 7 parts of butyl acetate was mixed immediately before coating to prepare a top coat. [Hereinafter referred to as top coat (B)] <Preparation of primer> 70% solution of bisphenol A type epoxy resin ["Epicoat #1001" (trade name manufactured by Ciel Chemical Co., Ltd.)]
Main component consisting of 100 parts, titanium dioxide 5 parts, talc 40 parts, organic bentonite 0.5 parts, xylene 10 parts and polyamide resin ["Thomide #410" (product name manufactured by Fuji Kasei Kogyo Co., Ltd.]) 18 parts, xylene 12 parts The following curing agent components were mixed immediately before painting to prepare a primer. Examples 1 to 4 and Comparative Examples 1 to 6 The aqueous coating compositions shown in Table 1 were coated with an average height difference of about 7 mm.
The cement composition was spray-coated onto the surface of an uncured cement board press-formed to have a wavy uneven surface to a dry film thickness of approximately 2.0 mm, and the cement board and coating were coated using the curing method shown in Table 1. Cured and hardened. In addition, the natural curing in the table is left in the atmosphere for 10 days.
Water curing was performed by immersing in water at 20°C for one day and then leaving it in the air for one week, and steam curing was performed at a temperature of 40°C and humidity of 98% for 12 hours. Next, in Examples 1 and 4 and Comparative Examples 1 to 5, a primer was spray coated to a dry film thickness of about 15 μm and allowed to air dry. Next, for Examples 1 to 4 and Comparative Examples 1 to 5, the top coat paints shown in Table 1 were spray coated to a dry film thickness of about 30 μm, and dried for 30.2 hours. In Comparative Example 6, no primer or top coat was applied. The test results for the adhesion, efflorescence acceleration, freeze-thaw cycle, accelerated weather resistance, and coating film appearance of the obtained colored cement board are shown in the lower row of Table 1. The test method and evaluation were performed as follows. (1) Adhesion Test method: 2mm cellophane tape peeling test of coating film Evaluation: ◎...50/50, ○...49/50 to 40/50, ×
...39/50 or less (2) Efflorescens acceleration test Test method: 30 cycles in saturated slaked lime atmosphere [5℃ x 16 hours → 20℃ x 8 hours] Evaluation: ◎...No abnormality at all, ○...Extremely low Partial abnormality, ×... General abnormality (3) Freeze-thaw cycle test Test method: [-20℃ x 16 hours freezing → Room temperature x 8 hours] 40 cycles Evaluation: ◎...No abnormality at all, ○...Very partially There is an abnormality, ×... There is an abnormality on the entire surface (with cracks) (4) Accelerated weathering test Test method: Sunshine carbon irradiation for 500 hours Evaluation: ◎... No abnormality at all, ○... There is a very small abnormality, ×... Full surface Abnormality (with yoking) (5) Paint film appearance Test method: Visual judgment (however, the water-based coating composition paint film after curing and curing is judged) Evaluation: ◎...Uniform coating film formation, ◎...Very slight sagging in some parts , Cracking, ×...Many sagging and cracking As is clear from Table 1, the coating film obtained by the method of the present invention had excellent coating performance. On the other hand, Comparative Example 1 in which cement was added in excess as an aqueous coating composition, Comparative Example 2 in which hollow inorganic powder was not included, Comparative Example 3 in which epoxy resin was not included, and Comparative Example 4 in which acrylic resin was not included were all resistant to efflorescence. Comparative Example 5 had poor sensitivity, freeze-thaw resistance, etc., and also used vinyl acetate resin instead of acrylic resin.
In Comparative Example 6, in which no top coat was applied, poor weather resistance was obtained.

【table】

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Claims (1)

[Claims] 1. The following components are applied to the surface of an uncured cement product having an uneven surface: (a) () A copolymer emulsion resin of acrylic acid or methacrylic acid alkyl ester (the alkyl group has 1 to 8 carbon atoms). solid content)
...2 to 15% by weight () Bisphenol type epoxy emulsion resin solid content ...1 to 5% by weight () Hollow inorganic powder with average particle size of 30 to 300μ
...10 to 40% by weight () Cement ...20 to 60% by weight () 0.8 to 1.2 equivalents of polyamide resin or aliphatic polyvalent amine curing agent of the bisphenol type epoxy emulsion resin (), and further filling if necessary and additives, and the weight ratio of [()+()]/() is 0.15~
An aqueous coating composition having a viscosity of 50 to 500 poise is applied, consisting of 100 parts by weight of the mixture in the range of 0.28 and (b) 15 to 70 parts by weight of water, and the cement product and the coating are simultaneously cured and cured, and then 1. A method for producing a cement product having an uneven surface, the method comprising applying a top coat of paint mainly composed of a fluorine-containing copolymer and a polyisocyanate compound.