JP2625927B2 - Coating method of cement base material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a method for coating a cement-based substrate, and more specifically, a specific fluoroolefin copolymer and a specific isocyanate compound are essential. The present invention relates to a novel method for coating a cement-based substrate, which can form a coating film having extremely excellent durability by applying a top coat as a component.

(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 for construction and building material applications, and provide cosmetics. For the purpose of improving durability and durability, an acrylic thermoplastic or thermosetting overcoat has been applied to the surface of the surface through an intermediate layer. However, such paints have a drawback that gloss is reduced in a relatively short period of time due to insufficient weather resistance, and cosmetics are impaired.

In order to improve such a drawback, a fluoroolefin-based copolymer containing a reactive functional group and a curing agent as a topcoat paint through an intermediate layer and a curing agent as a binder component,
A method of applying a highly weather-resistant paint has been proposed (JP-B-62-16141).

However, when the proposed paint is applied to a cement-based substrate, it is not possible to follow cracks generated in the cement-based substrate over time, and a sealer or a waterproof layer required for a top coat is required. The protection function has been significantly reduced,
It cannot achieve the purpose of improving the durability of the substrate.

(Problems to be Solved by the Invention) The present inventors have conducted intensive studies in order to improve the above-mentioned disadvantages of the prior art, and as a result, a cement-based substrate provided with a sealer and / or a waterproof layer has a specific property. By applying a top coat containing a fluoroolefin copolymer and a specific isocyanate compound as essential components, it has been found that a coating film having extremely excellent durability, particularly excellent crack followability, can be obtained. Reached.

[Configuration of the invention]

(Means for Solving the Problems) To summarize the present invention, the present invention relates to a coating method of applying and curing a topcoat paint on a cement-based substrate provided with a sealer and / or a waterproof layer, wherein the topcoat paint comprises: (A) a fluoroolefin-based copolymer having an average of at least two hydroxyl groups in one molecule; and (B) an isocyanate compound which is an adduct of a polyether polyol and a diisocyanate, as essential components. The present invention relates to a method for coating a cement base material, which is a feature of the invention.

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

First, the components of the top coat used in the coating method of the present invention will be described.

The (A) fluoroolefin-based copolymer constituting the top coating composition of the present invention is one having an average of at least two hydroxyl groups in one molecule. If the number of hydroxyl groups is less than this, the durability of the coating film decreases, which is not preferable.

As the (A) fluoroolefin-based copolymer component, a fluoroolefin is contained in an amount of 15 to 70% by weight, preferably 20 to 70% by weight.
1 to 30% by weight of a vinyl monomer having a hydroxyl group.
%, Preferably 3 to 20% by weight, and 5 to 84% by weight of another copolymerizable monomer.

If the amount of the fluoroolefin is less than the above-mentioned range, the durability is lowered, and if it is more than that, the workability of the paint is lowered, which is not preferable. If the amount of the hydroxyl group-containing vinyl monomer is less than the above-mentioned range, the solvent resistance and durability decrease, and if it is more than that, crack followability decreases, which is not preferable.

Examples of the fluoroolefin used in the present invention include vinyl fluoride, vinylidene fluoride, trifluoroethylene, tetrafluoroethylene, chlorotrifluoroethylene, bromotrifluoroethylene, pentafluoropropylene, hexafluoropropylene, and trifluoromethyl trifluoroethylene. Perfluoroalkyl perfluorovinyl ether such as fluorovinyl ether, pentafluoroethyl trifluorovinyl ether or heptafluoropropyl trifluorovinyl ether, and the like, preferably vinyl fluoride, vinylidene fluoride, tetrafluoroethylene, chlorotrifluoroethylene , Hexafluoropropylene and (per) fluoroalkyl trifluorovinyl ether (however, having 1 to 18 carbon atoms)

The hydroxyl group-containing vinyl monomer used in the present invention includes 2-hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether, 2-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, 3-hydroxybutyl vinyl ether, and 2-hydroxy- Hydroxyl-containing vinyl ethers such as 2-methylpropyl vinyl ether, 5-hydroxypentyl vinyl ether and 6-hydroxyhexyl vinyl ether; adducts of the above vinyl ethers with ε-caprolactone; 2-hydroxyethyl (meth) allyl ether;
Hydroxypropyl (meth) allyl ether, 2-hydroxypropyl (meth) allyl ether, 4-hydroxybutyl (meth) allyl ether, 3-hydroxybutyl (meth) allyl ether, 2-hydroxy-2-methylpropyl (meth) allyl Allyl ethers containing a hydroxyl group such as ether, 5-hydroxypentynyl (meth) allyl ether, 6-hydroxyhexyl (meth) allyl ether; and adducts of the above-mentioned allyl ethers and ε-caprolactone.

Other copolymerizable monomers include methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, tert-butyl vinyl ether, n-bentyl vinyl ether, n-hexyl vinyl ether, n -Octyl vinyl ether, 2-
Alkyl vinyl ethers or substituted alkyl vinyl ethers such as ethylhexyl vinyl ether, chloromethyl vinyl ether, chloroethyl vinyl ether, benzyl vinyl ether or phenylethyl vinyl ether; cycloalkyl vinyl ethers such as cyclopentyl vinyl ether, cyclohexyl vinyl ether or methylcyclohexyl vinyl ether; vinyl
2,2-dimethylpropanoate, vinyl 2,2-dimethylbutanoate, vinyl 2,2-dimethylpentanoate, vinyl 2,2-dimethylhexanoate, vinyl 2,2-dimethylbutanoate, vinyl 2-ethyl-2-methylbutanoate, vinyl 2-ethyl-2-methylpentanoate, vinyl 3-chloro-2,2-dimethylpropanoate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate , Vinyl caproate, vinyl caprylate,
Vinyl caprate, vinyl laurate, branched aliphatic carboxylic acid vinyl of C _9, branched aliphatic carboxylic acids vinyl C _10, C
₁₁ , branched vinyl aliphatic carboxylate, vinyl stearate vinyl cyclohexane carboxylate, methyl methyl cyclohexane carboxylate, vinyl benzoate, or P-tert
Carboxylic acid vinyl esters such as -butyl benzoate; methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, iso
-Propyl (meth) acrylate, n-butyl (meth)
Acrylate, iso-butyl (meth) acrylate, ter
such as t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, dibromopropyl (meth) acrylate or alkoxyalkyl (meth) acrylate Acrylic monomers; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3
-Hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, di-2-hydroxyethyl fumarate, mono-2-hydroxyethyl-monobultifumarate Or α, β such as polypropylene glycol or polyethylene glycol mono (meth) acrylate, Praxel FM, FA monomer (caprolactone-added monomer manufactured by Daicel Chemical Industries, Ltd.)
-Hydroxyalkyl esters of ethylenically unsaturated carboxylic acids or hydroxyl-containing monomers other than the above-mentioned hydroxyl-containing vinyl ethers and allyl ethers, such as adducts of these with ε-caprolactone; glycidyl (meth)
Epoxy group-containing monomers such as acrylate, (β-methyl) glycidyl (meth) acrylate and (meth) allyl glycidyl ether; diesters of an unsaturated dicarboxylic acid such as fumaric acid or itaconic acid with a monovalent alele; ) Acrylic acid; maleic acid, fumaric acid, itaconic acid, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3
Hydroxyl-containing monomers such as -hydroxypropyl (meth) acrylate, 2-hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether, 2-hydroxypropyl vinyl ether and 4-hydroxybutyl vinyl ether, and maleic acid, succinic acid, phthalic acid, hexahydro Acid group-containing monomers such as adducts of polycarboxylic acids such as phthalic acid with anhydrides; acid anhydride group-containing monomers such as maleic anhydride, itaconic anhydride and vinyl ester of trimellitic anhydride An aromatic vinyl monomer such as styrene, α-methylstyrene, P-tert-butylstil, vinyltoluene or an olefin other than a fluoroolefin such as (meth) acrylonitrile, vinyl chloride, vinylidene chloride; vinyltrimethoxysilane ,
Vinyltriethoxysilane, vinyltripropoxysilane, vinylmethyldiethoxysilane, vinyltris (β
-Methoxyethoxy) silane, allyltrimethoxysilane, trimethoxysilylethylvinylether, triethoxysilylethylvinylether, methyldimethoxysilylethylvinylether, trimethoxysilylpropylvinylether, triethoxysilylpropylvinylether, methyldimethoxysilylpropylvinylether, γ- ( There are vinyl monomers containing a hydrolyzable silyl group such as (meth) acryloyloxypropyltrimethoxysilane, γ- (meth) acryloyloxypropyltriethoxysilane or γ- (meth) acryloyloxypropylmethyldimethoxysilane. .

Among the above copolymerizable monomers, those selected from alkyl vinyl ethers, cycloalkyl vinyl ethers, and carboxylic acid vinyl esters are preferred. The above-mentioned unsaturated group-containing copolymerizable monomer may be appropriately determined for each monomer component and the amount used in view of the copolymer, coating workability, coating performance such as weather resistance, and the like.

The fluoroolefin copolymer component (A) of the present invention can be prepared by any known method such as solution (pressurization), bulk, suspension polymerization, etc. Is the most convenient.

As the radical polymerization initiator used at that time, acetyl peroxide, benzoyl peroxide, lauroyl peroxide, methyl ethyl ketone peroxide, cyclohexanone peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, di-tert-butyl peroxide , Dicumyl peroxide, tert-butyl peroxybenzoate, tert
-Peroxides such as butyl peroxyoctoate, tert-butyl peroxyacetate and tert-butyl peroxypivalate; azo compounds such as azobisisobutyronitrile or azobisisovaleronitrile are typical. It is listed as.

Further, as a solvent used at the time of polymerization, toluene,
Hydrocarbons such as xylene, cyclohexane, n-hexane and octane; ester systems such as methyl acetate, ethyl acetate, butyl acetate and ethylene glycol monoethyl ether acetate; such as acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone and cyclohexanone Ketones; amides such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone; or methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol, tert-butanol, ethylene glycol mono Representative examples include alcohol solvents such as alkyl ethers, and mixtures thereof.

In the polymerization, a chain transfer agent such as lauryl mercaptan, 2-mercaptoethanol, and α-methylstyrene dimer can also be used.

The weight average molecular weight of the (A) fluoroolefin-based copolymer component of the present invention is preferably in the range of 7,000 to 300,000, and if it is less than this, durability decreases, while if it is more than this, coating workability becomes poor. It is not practical because it gets worse.

Commercial products of the fluoroolefin copolymer component (A) include fluorate, K-700, K-701 (manufactured by Dainippon Ink and Chemicals, Inc.), Lumiflon LF-200 and LF-30.
2, LF-400, LF-601, LF-701 (manufactured by Asahi Glass Co., Ltd.), Serafulcoat (manufactured by Central Glass Co., Ltd.) and the like.

The (A) fluoroolefin-based copolymer component of the present invention has been described above mainly on the solvent-soluble type, but may be in the form of a non-aqueous dispersion dispersed in a solvent,
Further, it is needless to say that particles containing partially gelled particles may be used.

Next, the isocyanate compound component (B) constituting the top coat of the present invention is an adduct of a polyether polyol and a saturated hydrocarbon diisocyanate compound.

The polyether polyol has a number average molecular weight of 400
Preferably it is ~ 1,500. That is, in order for the (B) isocyanate compound component to have sufficient flexibility and crack followability, a molecular weight of 400 or more is required.
If it exceeds 500, the compatibility with the main component (A) of the fluoroolefin-based copolymer component is undesirably reduced.

On the other hand, the average number of hydroxyl groups in one molecule of the polyether polyol is preferably in the range of 2 to 3, and more preferably in the range of 2 to 2.5. That is, when the average number of hydroxyl groups is less than 2, in the combination with the main component (A) fluoroolefin copolymer component, it is no longer possible to obtain a crosslinked coating film,
Conversely, if the average number of hydroxyl groups exceeds 3, the crosslinking density tends to be too high and the flexibility tends to be impaired.

In the present invention, a polyether polyol having an average number of hydroxyl groups of 2 and a polyether polyol having the same number of hydroxyl groups of 3 can be mixed at an arbitrary ratio to produce a polyether polyol adjusted to a desired average number of hydroxyl groups. Needless to say.

Examples of the saturated hydrocarbon diisocyanate compound as one component (essential pigment component) of the isocyanate compound component (B) of the present invention include 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, and 2,2,4.
Most preferred are alkylene diisocyanates such as -or 2,4,4-trimethylhexamethylene diisocyanate or 2,6-diisocyanate methyl caproate.

1,3- or 1,4-diisocyanatocyclohexane, 1,3- or 1,4-bis (isocyanatomethyl)
-Cyclohexane, dicyclohexylmethane-4,4'-
Diisocyanate or 3-isocyanatomethyl-3,
Cycloalkylene diisocyanates such as 5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate) can also be used as the saturated hydrocarbon diisocyanate compound, but such cycloalkylene diisocyanates generally have a hard structure and are particularly excellent in flexibility. In order to obtain an isocyanate compound, it is preferable to use an alkylene diisocyanate in combination of 30% by weight or more.

In order to prepare the (B) isocyanate compound component, the above-mentioned polyether polyol may be urethanized in an excess of a saturated hydrocarbon diisocyanate compound. At this time, the excess ratio may be urethanized so that the equivalent ratio (NCO / OH) of the isocyanate of the saturated hydrocarbon diisocyanate compound to the hydroxyl group of the polyether polyol is in the range of 5 to 20.

The cement-based substrate to which the coating method of the present invention is applied,
The term refers to various base materials prepared using the cement-based material as an essential component as described above.

In the present invention, the sealer previously applied to the cement-based substrate is to prevent the leaching of alkali from the cement-based substrate, to adhere the waterproof layer and the cement-based substrate, or to apply a topcoat paint. It is used to improve the adhesion between the coating layer and the cement-based substrate. Specific examples of such sealers include acrylic lacquer-type paint, acrylic urethane-based paint, acrylic emulsion paint, moisture-curable urethane resin paint, and chlorinated polyolefins such as chlorinated polyethylene and chlorinated polypropylene dissolved in a solvent. Lacquer-type paints, polyamine or polyamideamine-curable epoxy resin paints, and further, lacquer-type epoxy resin paints, and the like can be given. Such paints may be clear paints or enamel paints containing various pigments as described below.

Next, the waterproof layer used in the present invention refers to an organic coating applied to a relatively thick film in order to prevent deterioration of the base material due to intrusion of water such as rainwater from the surface of the coating, Representative materials used to form such a waterproof layer include acrylic emulsion paints, ethylene-vinyl acetate copolymer paints, vinyl chloride copolymer sol paints,
Various epoxy resin-based paints, acrylic urethane resin-based paints, and the like can be given.

In order to obtain a cement-based substrate to which a sealer and a waterproof layer are formed as described above (hereinafter referred to as a waterproof paint), only the sealer is applied.
Prescriptions, such as applying a waterproof paint after applying a sealer or applying only a waterproof paint, can be applied. Known methods such as brush coating, spray coating, and roller coating can be applied to obtain a cement-based substrate coated by such a method.
After coating, it can be dried by heating if necessary.

In the overcoat paint comprising the component (A) and the component (B) in the present invention, a coloring pigment and / or metal powder can be used as necessary. In this case, it is preferable to use 5-200 parts by weight based on 100 parts by weight of the fluoroolefin-based copolymer component (A) for the purpose of providing cosmetics and protecting the waterproof layer.

The top coating composition of the present invention may further contain various resins and solvents, if necessary, flow control agents, anti-separation agents, antioxidants, ultraviolet absorbers, light stabilizers or silane coupling agents. It goes without saying that various conventional additives can be added.

Typical examples of the various resins include fibrous resins such as nitrocellulose and cellulose acetate butyrate, vinyl chloride / vinyl acetate copolymer resins, ketone resins, and the like.
Examples include petroleum resins, acrylic polymers, oil-free alkyd resins, alkyd resins, and epoxy resins.

As the solvents, the same solvents as those used in preparing the fluoroolefin-based copolymer of the present invention and the mixtures thereof can be used.

As a method of applying the top coat of the present invention obtained as described above to a cement-based substrate provided with a sealer and / or a waterproof layer, a conventional method such as air spray, airless spray, electrostatic coating, or roll coater is used. Method may be used. And after painting, let it dry at room temperature for several days, or at a temperature of 60-150 ° C for 10-30
By heating for minutes, a cured coating can be obtained.

(Examples) Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

In the following, all parts and percentages are by weight unless otherwise specified.

Reference Example 1 (Preparation Example of Fluoroolefin Copolymer) In a stainless steel autoclave of 2 sufficiently substituted with nitrogen, p-tert-butyl benzoate vinyl ester was added.
390 parts of Beoba 9 (Netherlands Shell Co., vinyl esters to C ₁₀ comprising branched fatty acid) 100 parts of 4-hydroxybutyl vinyl ether 110 parts, 430 parts of butyl acetate, azobisisovaleronitrile (ABVN) 15 parts of tertiary Lebutylbutyl peroxy octoate (TBPO) 10 parts, Sanol LS-
765 [manufactured by Sankyo Co., Ltd., amine compound] 3 parts were charged.

Then liquefied and collected chlorotrifluoroethylene 400
The mixture was allowed to react at 60 ° C. for 15 hours with stirring to reach a nonvolatile content (NV) of 67%. After cooling to room temperature, 175 parts of xylene was added, and a NV60% fluoroolefin copolymer was added. Obtained. This has a weight average molecular weight of 140,000, and is hereinafter abbreviated as copolymer A-1.

<Reference Example 2> (Preparation Example of Fluoroolefin Copolymer) Except that the vinyl monomer in Reference Example 1 was changed to Vover 9 250 parts 4-hydroxybutyl vinyl ether 100 parts ethyl vinyl ether 150 parts chlorotrifluoroethylene 500 parts After reacting in the same way and reaching NV 68%,
After cooling to room temperature, 194 parts of xylene was added to obtain an NV60% fluoroolefin copolymer. It has a weight average molecular weight of 120,000 and is hereinafter abbreviated as copolymer A-2.

<Reference Example 3> (Preparation Example of Fluoroolefin Copolymer) In the same manner as in Reference Example 1, except that the vinyl monomer was changed to 410 parts of cyclohexyl vinyl ether, 100 parts of 4-hydroxybutyl vinyl ether and 490 parts of chlorotrifluoroethylene. After reacting and reaching NV 68%,
After cooling to room temperature, 194 parts of xylene was added to obtain an NV60% fluoroolefin copolymer. It has a weight average molecular weight of 140,000, and is hereinafter abbreviated as copolymer A-3.

<Reference Example 4> (Preparation example of isocyanate compound) "Hiplox DP-1000" [Dainippon Ink Co., Ltd.] was placed in a glass four-necked flask equipped with a stirrer, a thermometer, a nitrogen gas inlet tube, and a waste gas port. Chemical Industry Co., Ltd., polyether polyol, number average molecular weight 1000, average number of hydroxyl groups in one molecule 2.0] 700 parts and "HIPROX TG-700"
[Dainippon Ink Chemical Industry Co., Ltd., polyether polyol, number average molecular weight 700, average number of hydroxyl groups in one molecule 3.0]
350 parts, and hexamethylene diisocyanate 2300
The part was heated under a nitrogen gas atmosphere at 90 to 100 ° C. for 7 hours to complete the urethanization reaction (NCO / OH equivalent ratio 11.0).

After the reaction mixture was cooled to room temperature, 1000 g of the mixture was distilled at 150 ° C. in a thin film evaporator under a reduced pressure of 0.3 to 0.5 torr to remove unreacted hexamethylene diisocyanate. A transparent isocyanate compound having fluidity was obtained.

The isocyanate compound content of the isocyanate compound obtained by the thin film distillation is 8.0%, and this isocyanate compound is hereinafter abbreviated as B-1.

<Reference Example 5> (Preparation Example of Isocyanate Compound) In Reference Example 4, as a polyether polyol,
"HIPROX DP-600" [manufactured by Dainippon Ink and Chemicals, Inc., polyether polyol, number average molecular weight 60
0, the average number of hydroxyl groups in one molecule was 2.0], and a transparent syrupy isocyanate compound was obtained in the same manner except that the equivalent ratio of NCO / OH was 12.0. This has an isocyanate group content of 9.2%. Hereinafter, this isocyanate compound is abbreviated as B-2.

<Reference Example 6> (Preparation Example of Isocyanate Compound) In Reference Example 4, as a polyether polyol,
Hyprox DP-1000 and HyproxTM-40
0 "[manufactured by Dainippon Ink and Chemicals, Inc., polyether polyol, number average molecular weight 430, average number of hydroxyl groups in one molecule
3.0] and a mixture of 700: 230 in a ratio of 700: 230, except that the equivalent ratio of NCO / OH of hexamethylene diisocyanate was 10.5 to obtain a transparent syrupy compound in the same manner as in Reference Example 4. Obtained. This has an isocyanate group content of 8.8%. Hereinafter, this isocyanate compound is abbreviated as B-3.

<Reference Examples 7 to 10 / Comparative Reference Examples 1 and 2> (Examples of Preparation of Top Coating Paint) Glass beads were added to a mixture of a fluoroolefin-based copolymer, a coloring pigment, and the like shown in Table 1, and a sand mill was used. After the mixture was dispersed for 1 hour, a curing agent was blended in the proportions shown in Table 1 and further aired with a mixed solvent of toluene / xylene / butyl acetate / cellosolve acetate = 30/30/30/10 (weight ratio). Dilutions were made to sprayable viscosities to give topcoats I-VI.

<Example 1> An ethylene-vinyl acetate copolymer paint (dry film thickness: 20μ) as a sealer on a slate plate having a thickness of 5mm as a base material, and an acrylic-styrene copolymer elastic paint (dry film thickness: 2 to 10mm) as a waterproof layer ) Was sprayed by air spray and dried at room temperature, and then a top coat I was applied by air spray to a dry film thickness of 50 μm.

After leaving it to stand at room temperature for one week and drying, it was used as a sample for various coating film tests described below.

<Examples 2 to 6 / Comparative Examples 1 and 2> In the same manner as in Example 1, coatings shown in Table 2 were applied and dried to obtain samples for various coating film performance tests described later.

<Results of Coating Film Performance Test> Table 3 shows the results of subjecting the various coating film performance test samples obtained in Examples 1 to 7 and Comparative Examples 1 and 2 to various performance tests.

It has been confirmed that the method for coating a cement substrate according to the present invention is extremely superior to the conventional method, particularly in a thermal cycle test (a measure of crack followability).

[Effect of the Invention] The method for coating a cement-based substrate of the present invention, that is, a cement-based substrate provided with a sealer and / or a waterproof layer,
Topcoat dye comprising (A) a fluoroolefin-based copolymer having an average of at least two hydroxyl groups in one molecule, and (B) an isocyanate compound which is an adduct of polyether polyol and diisocyanate as essential components. By coating and curing, a coating film having excellent durability and crack followability can be formed.

Therefore, the coating method of the present invention is applied to various cement-based substrates, and can improve the cosmetic properties and durability of the cement-based substrates over a long period of time, and its utility value is extremely large.

Claims (6)

(57) [Claims] 1. A coating method in which a top coat is applied to a cement-based substrate provided with a sealer and / or a waterproof layer and cured, wherein the top coat has at least two hydroxyl groups per molecule on average. A fluoroolefin copolymer (A) having the formula (I) and an isocyanate compound (B), which is an adduct of a polyether polyol and a diisocyanate, as essential film-forming components. Painting method. 2. The fluoroolefin-based copolymer (A) comprises 15 to 70% by weight of the fluoroolefin (a).
And 1 to 30% by weight of a vinyl monomer (b) having a hydroxyl group, and 5 to 84% by weight of another monomer (c) capable of being copolymerized. The coating method according to claim 1, wherein the coating is performed. 3. The above-mentioned fluoroolefin-based copolymer (A) has the following fluoroolefin (a):
At least one selected from the group consisting of tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, vinyl fluoride, vinylidene fluoride, and (per) fluoroalkyltrifluorovinyl ether having 1 to 18 carbon atoms in the alkyl group; The coating method according to claim 1, which is obtained by using a compound. 4. The fluoroolefin-based copolymer (A) comprises, as the other copolymerizable monomer (c), an alkyl vinyl ether, a cycloalkyl vinyl ether and a carboxylic acid vinyl ester. The coating method according to claim 1, wherein the coating method is obtained by using at least one compound selected from the group. 5. The coating method according to claim 1, wherein the fluoroolefin-based copolymer (A) has a weight average molecular weight in the range of 7,000 to 300,000. 6. The method according to claim 1, wherein the isocyanate compound (B) is
It has an average of 2-3 hydroxyl groups in one molecule, and
2. A compound obtained by reacting a polyether polyol having a number average molecular weight in the range of 0 to 1,500 with an excess of a saturated hydrocarbon diisocyanate compound.
Painting method described in.