Water-based coating composition, coating film, and substrate with coating film

Abstract

To provide a coating composition capable of forming a coating film having excellent flame retardancy and water resistance, while also exhibiting excellent storage stability under high-temperature conditions.SOLUTION: A water-based coating composition according to the present invention comprises an acrylic resin-based emulsion (A) and a flame retardant (B), wherein the flame retardant (B) contains a metal salt of phosphinic acid, and the pH of the water-based coating composition is from 2.5 to 4.5 inclusive.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a water-based coating composition, particularly a water-based coating composition for inorganic substrates. The present invention also relates to a coating film formed from the water-based coating composition, and to a substrate having the coating film on the substrate. [Background technology]

[0002] Traditionally, inorganic base materials such as asbestos cement boards and calcium silicate boards are non-flammable and have excellent durability, so they have been coated with paint and used as inorganic building materials. In particular, inorganic building materials have been used as exterior walls (base material: siding boards) for houses, etc. Since exterior walls require flame retardancy, components that impart flame retardancy, such as flame retardants, have been mixed into the paint.

[0003] Flame retardants are also used in various fields. For example, polyphosphates such as ammonium polyphosphate are used as flame retardants in fields such as fiber processing, adhesives, etc., such as carpet backing agents (see Patent Document 1). Ammonium polyphosphate is used as a flame retardant in heat-resistant protective materials for building structures (see Patent Document 2). Phosphinate salts are also used as flame retardants in covering materials for flooring materials (see Patent Document 3). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2005-187582 A [Patent Document 2] JP 2017-171852 A [Patent Document 3] JP 2005-036230 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the present inventors have found a technical problem that the water resistance of the coating film is poor when ammonium polyphosphate, the flame retardant described in Patent Document 1 and Patent Document 2, is blended into the water-based paint composition.The present inventors have also found a technical problem that the paint becomes acidic when a phosphinate salt, the flame retardant described in Patent Document 3, is blended into the water-based paint composition, resulting in poor storage stability, particularly in a high-temperature environment (e.g., 50°C).

[0006] The present invention has been made in view of the above-mentioned background art, and an object of the present invention is to provide an aqueous coating composition capable of forming a coating film having excellent flame retardancy and water resistance while having excellent storage stability in a high-temperature environment (e.g., 50°C). [Means for solving the problem]

[0007] The present inventors have conducted extensive research to solve the above problems, and have found that the above problems can be solved by adjusting the pH of a water-based coating composition to a specific range, the water-based coating composition containing an acrylic resin emulsion (A) and a metal phosphinate as a flame retardant (B). The present invention has been completed based on this finding.

[0008] That is, according to the present invention, the following inventions are provided. [1] A water-based coating composition comprising an acrylic resin emulsion (A) and a flame retardant (B), The flame retardant (B) contains a metal phosphinate, The aqueous coating composition has a pH of 2.5 or more and 4.5 or less. [2] The aqueous coating composition according to [1], wherein the metal phosphinate comprises aluminum dialkylphosphinate. [3] The aqueous coating composition according to [1] or [2], wherein the pH of the acrylic resin emulsion (A) is 3.0 or more and 6.0 or less. [4] The aqueous coating composition according to any one of [1] to [3], wherein the aqueous coating composition has a pH of 3.0 or more and 4.2 or less. [5] The aqueous coating composition according to any one of [1] to [4], which is used for coating inorganic building materials. [6] A coating film formed from the coating composition according to any one of [1] to [5]. [7] A substrate having a substrate and the coating film according to [6] formed on the substrate. [8] The substrate having a coating film according to [7], wherein the substrate is an inorganic building material. [9] A step of applying the coating composition according to any one of [1] to [5] to a substrate; A step of drying the applied coating composition to form a coating film; A method for producing a substrate having a coating film, comprising: Effect of the Invention

[0009] According to the present invention, it is possible to provide a coating composition capable of forming a coating film having excellent flame retardancy and water resistance while having excellent storage stability in a high-temperature environment (e.g., 50° C.). Furthermore, according to the present invention, it is possible to provide a coating film having excellent flame retardancy and water resistance and a substrate having said coating film. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention will now be described in more detail. In this specification, the term "(meth)acrylate" refers to acrylate and methacrylate. The solids (film-forming components) of the water-based paint composition refer to the components remaining after removing volatile components such as water from the water-based paint composition, which will form a paint film when cured.

[0011] <Water-based paint composition> The water-based coating composition according to the present invention contains at least an acrylic resin emulsion (A) and a flame retardant (B). The water-based coating composition according to the present invention may further contain water and other components. The coating film formed from the water-based coating composition according to the present invention is excellent in flame retardancy and water resistance. The water-based coating composition capable of forming such a coating film can be suitably used for coating inorganic substrates requiring these properties.

[0012] The pH of the aqueous coating composition according to the present invention is from 2.5 to 4.5, preferably from 3.0 to 4.2, and more preferably from 3.2 to 4.1. When the water content of the aqueous coating composition is within the above range, the storage stability of the aqueous coating composition in a high-temperature environment (e.g., 50°C) can be improved.

[0013] The water content of the water-based coating composition according to the present invention is not particularly limited, and can be appropriately adjusted to have a viscosity suitable for coating. The water content of the water-based coating composition is preferably 40% by mass or more and 75% by mass or less, more preferably 45% by mass or more and 70% by mass or less, and even more preferably 45% by mass or more and 65% by mass or less. The water content of the water-based coating composition includes not only the amount of water separately mixed, but also the amount of water contained in each component such as the acrylic resin emulsion (A). If the water content of the water-based coating composition is within the above numerical range, it can improve the coating workability and the penetration into inorganic substrates.

[0014] Each component of the water-based paint composition according to the present invention will now be described in detail.

[0015] (Acrylic resin emulsion (A)) The acrylic resin contained in the acrylic resin emulsion is preferably a homopolymer of (meth)acrylate or a copolymer of (meth)acrylate and a monomer copolymerizable with (meth)acrylate.

[0016] When the acrylic resin is a copolymer of (meth)acrylate and a monomer copolymerizable with (meth)acrylate, the constituent units derived from (meth)acrylate are preferably 20 to 99.9 mass%, more preferably 40 to 99.5 mass%, and the constituent units derived from a monomer copolymerizable with said constituent units are preferably 0.1 to 80 mass%, more preferably 0.5 to 60 mass%, where the amount of all constituent units in the acrylic resin is taken as 100 mass%.

[0017] The weight average molecular weight (Mw) of the acrylic resin is preferably 5,000 to 300,000, and more preferably 10,000 to 200,000. When the acrylic resin has the above composition or molecular weight, it is easy to form a coating film having excellent water resistance and coating film strength.

[0018] The acrylic resin is produced by appropriately selecting monomers so as to obtain the above-mentioned component composition and weight average molecular weight, etc., and by a known method, such as solution radical polymerization.

[0019] As the polymerizable or copolymerizable monomer, a (meth)acrylate or a monomer copolymerizable with a (meth)acrylate is used.

[0020] Specific examples of the (meth)acrylate include alkyl esters or cycloalkyl esters of (meth)acrylic acid having 1 to 18 carbon atoms, such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, (n-, i-, t-)butyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, decyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, and cyclohexyl (meth)acrylate; alkoxy esters of (meth)acrylic acid having 2 to 18 carbon atoms, such as methoxybutyl (meth)acrylate, methoxyethyl (meth)acrylate, and ethoxybutyl methacrylate; dialkylamino esters of (meth)acrylic acid, such as dimethylaminoethyl (meth)acrylate and dimethylaminopropyl (meth)acrylate; and glycidyl (meth)acrylate. Among these, it is preferable to use methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. These monomers may be used alone or in combination of two or more.

[0021] Examples of monomers copolymerizable with (meth)acrylate include styrene, vinyl acetate, maleic acid, itaconic acid, acrylic acid, methacrylic acid, acrylic acid amide, vinyl toluene, acrylonitrile, and aliphatic carboxylate metal (meth)acrylate. Among these, it is preferable to use styrene, vinyl acetate, acrylic acid, and methacrylic acid. These monomers may be used alone or in combination of two or more.

[0022] The acrylic resin emulsion is preferably an aqueous emulsion, and can be prepared, for example, by emulsifying the acrylic resin. Examples of the emulsification method include conventionally known methods such as natural emulsification, interfacial chemical emulsification, electrical emulsification, capillary emulsification, phase inversion emulsification, mechanical emulsification, and ultrasonic emulsification, and an emulsifier may be used to prepare the emulsion. In addition, the acrylic emulsion can be prepared directly by emulsion polymerization. The emulsifier is not particularly limited, and can be appropriately selected from anionic emulsifiers, cationic emulsifiers, amphoteric emulsifiers, and nonionic emulsifiers. Among these, the use of an anionic emulsifier can improve the storage stability of the aqueous coating composition under high temperature conditions (e.g., 50°C).

[0023] The acrylic resin emulsion is preferably acidic so that the pH of the water-based coating composition is within the above-mentioned specific range.In particular, the pH of the acrylic resin emulsion is preferably 3.0 or more and 6.0 or less, more preferably 3.2 or more and 5.8 or less, and even more preferably 3.5 or more and 5.5 or less.If the pH of the acrylic resin emulsion is within the above-mentioned numerical range, the water-based coating composition of the present invention can be easily produced, and its storage stability can be improved.

[0024] The solid content of the acrylic resin emulsion is preferably 30 to 70% by mass, and more preferably 40 to 60% by mass, based on 100% by mass of the acrylic resin emulsion.

[0025] The acrylic resin emulsion may be a commercially available product, such as Ultrasol N-80 (manufactured by Aica Kogyo Co., Ltd.).

[0026] The content of the acrylic resin is preferably 20% by mass or more and 75% by mass or less, more preferably 25% by mass or more and 60% by mass or less, and even more preferably 25% by mass or more and 55% by mass or less, based on the solid content (film-forming components) of the coating composition. If the content of the acrylic resin is within the above numerical range, a coating film having excellent flame retardancy and water resistance can be formed.

[0027] (Flame retardant (B)) The flame retardant (B) contains a metal phosphinic acid salt. Examples of the phosphinic acid include dimethylphosphinic acid, ethylmethylphosphinic acid, diethylphosphinic acid, methyl-n-propylphosphinic acid, isobutylmethylphosphinic acid, octylmethylphosphinic acid, methylphenylphosphinic acid, and diphenylphosphinic acid. Among these, dialkylphosphinic acids such as dimethylphosphinic acid, ethylmethylphosphinic acid, diethylphosphinic acid, methyl-n-propylphosphinic acid, isobutylmethylphosphinic acid, and octylmethylphosphinic acid are preferred, and diethylphosphinic acid is more preferred. Examples of the salt include aluminum salts, magnesium salts, calcium salts, and zinc salts. Among these, aluminum salts and magnesium salts are preferred, and aluminum salts are more preferred.

[0028] The metal phosphinate is preferably a metal dialkylphosphinate. Examples of the metal dialkylphosphinate include aluminum dialkylphosphinate such as dimethyl aluminum phosphinate, ethyl methyl aluminum phosphinate, diethyl aluminum phosphinate, methyl-n-propyl aluminum phosphinate, isobutyl methyl aluminum phosphinate, and octyl methyl aluminum phosphinate, and magnesium dialkylphosphinate such as dimethyl magnesium phosphinate, ethyl methyl magnesium phosphinate, diethyl magnesium phosphinate, methyl-n-propyl magnesium phosphinate, isobutyl methyl magnesium phosphinate, and octyl methyl magnesium phosphinate. Among these, aluminum dialkylphosphinate is preferred, and aluminum diethylphosphinate is more preferred.

[0029] Although the mechanism of action of the coating composition of the present invention is unclear, it is speculated that the use of a metal phosphinate forms an oxygen-blocking layer called char during combustion (e.g., at 300°C or higher), blocking the oxygen required for combustion, thereby enabling the coating composition of the present invention to exhibit excellent flame retardancy. In addition, the use of a metal phosphinate in place of conventional flame retardants (such as ammonium polyphosphate) can improve the water resistance of the coating film formed.

[0030] The content of the metal phosphinate as the flame retardant (B) is preferably 10% by mass or more and 80% by mass or less, more preferably 35% by mass or more and 75% by mass or less, based on the solid content (film-forming component) of the coating composition. If the content of the metal phosphinate is within the above numerical range, a coating film having excellent flame retardancy and water resistance can be formed.

[0031] (Other Ingredients) The water-based coating composition according to the present invention may contain other components in addition to the above components, as long as the object of the present invention is not impaired. As other components, water, pigments, thickeners, dispersants, film-forming assistants, defoamers, organic solvents, film-forming assistants, pH adjusters, antifouling agents, non-reactive diluents, matting agents, antisettling agents, leveling agents, heat stabilizers, ultraviolet absorbers, light stabilizers, adhesion improvers, preservatives, antibacterial agents, antifungal agents, antiviral agents, silane coupling agents, colorants, plasticizers, etc. may be blended as necessary.

[0032] (water) The water is not particularly limited, and may be tap water, ion-exchanged water, etc. The water may be, for example, water derived from the acrylic resin emulsion (A), but it is preferable to further add water to the water-based coating composition from the viewpoints of making the preparation of the water-based coating composition easier, adjusting the viscosity of the composition, and improving the coating workability and the permeability into the inorganic substrate.

[0033] (Organic solvent) In order to prevent freezing in winter and to obtain a composition with better coating workability, an organic solvent that is miscible with water in any amount may be used. One type of organic solvent may be used, or two or more types may be used. Examples of such organic solvents include alcohol-based solvents having 1 to 3 carbon atoms, such as isopropyl alcohol and ethylene glycol, and glycol ether-based solvents, such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether.

[0034] (Film-forming agent) In order to obtain a composition having excellent coating workability and film-forming properties, a film-forming assistant may be used in any amount. One or more types of film-forming assistant may be used. Examples of such film-forming assistants include conventionally known alcohols, glycol ethers, and esters, such as alcohols having 1 to 3 carbon atoms such as isopropyl alcohol, and alcohols such as 2,2,4-trimethylpentanediol; glycol ethers such as ethylene glycol monobutyl ether, ethylene glycol diethyl ether, diethylene glycol monobutyl ether, diethylene glycol diethyl ether, propylene glycol diethyl ether, dipropylene glycol diethyl ether, and dipropylene glycol n-butyl ether; and esters such as 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate.

[0035] (pH adjuster) The pH adjuster is not particularly limited, and may be appropriately selected from conventionally known acidic or alkaline substances and their aqueous solutions. One or more pH adjusters may be used. Specifically, examples of the acidic substance include hydrochloric acid, sulfuric acid, and p-toluenesulfonic acid. Examples of the alkaline substance include sodium hydroxide, potassium hydroxide, ammonia, and alkanolamine.

[0036] <Method of preparing water-based coating composition> The water-based coating composition of the present invention can be obtained by mixing and stirring the above-mentioned components using a conventionally known device such as a mixer, disperser, stirrer, etc. Examples of such devices include a mixing and dispersion mill, a homodisper, a mortar mixer, a roll, a paint shaker, a homogenizer, etc.

[0037] <Coated substrate> The substrate with a coating film according to the present invention has a coating film formed from the above-mentioned water-based coating composition on at least a part of the substrate. In the present invention, the substrate with a coating film can be used, for example, on the front side (exterior wall side) or back side (house side) of a building. By using the substrate with a coating film, a building material with excellent flame retardancy and water resistance can be provided.

[0038] Building materials refer to components used in the structure and finishing of buildings. Examples include windows, walls, ceilings, floors, roofs, fixtures, wallpaper, etc. In particular, wall materials (siding, top coats, backsheets) and floor materials are preferred.

[0039] It is preferable to use an inorganic substrate as the substrate. The inorganic substrate is not particularly limited as long as it is a commonly used inorganic substrate. For example, inorganic substrates include asbestos cement boards, asbestos perlite boards, calcium silicate boards, asbestos cement calcium silicate boards, gypsum boards, mortar boards, pulp cement boards, wood chip cement boards, GRC (glass fiber reinforced cement) boards, CFRC (carbon fiber reinforced cement) boards, SFRC (steel fiber reinforced cement) boards, and rock wool inorganic moldings.

[0040] The density (specific gravity) of the inorganic base material is not particularly limited, but is, for example, 0.9 to 1.25 g / cm 2 is preferable, and 0.95 to 1.2 g / cm 2 The density of the inorganic base material can be measured by Archimedes' method.

[0041] The thickness of the inorganic base material is not particularly limited, but is, for example, preferably 0.1 to 30 mm, and more preferably 1 to 20 mm.

[0042] <Method of manufacturing substrate with coating film> The production of the inorganic substrate with a coating film according to the present invention comprises a step of coating the above-mentioned aqueous coating composition onto the substrate (coating step), and a step of drying and curing the coated coating composition to form a coating film (curing step).

[0043] (Painting process) The coating process is a process of coating at least one side of a substrate with the above-mentioned water-based coating composition by a conventionally known method.For example, the coating method can be selected from sponge roll coater, natural roll coater, reverse roll coater, curtain flow coater, knife coater, die coater, air spray, airless spray, roller, brush coating, immersion, etc. Among them, spray, flow coater, and sponge roll coater are preferably used because they can increase the amount of coating on the substrate and improve the coating film performance such as flame retardancy and water resistance.

[0044] The coating amount (wet film thickness) of the above-mentioned water-based coating composition is preferably 10 to 300 g / m from the viewpoint of drying property and curing property. 2 and more preferably 20 to 200 g / m 2 The water-based coating composition may be applied multiple times.

[0045] (hardening process) The curing step is a step of drying the coated surface of the building material, curing the applied water-based coating composition, and forming a coating film. Examples of drying methods include hot air drying (dryer, etc.). The drying temperature is preferably 10 to 200°C, and from the viewpoint of the smoothness and appearance of the coating film, the more preferred upper limit is 150°C, and from the viewpoint of the drying speed, the more preferred lower limit is 30°C.

[0046] From the viewpoint of coating film performance such as flame retardancy and water resistance, the thickness of the cured coating film is preferably 5 to 30 μm, and more preferably 10 to 20 μm. EXAMPLES

[0047] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0048] First, in order to prepare the water-based coating composition, the following raw materials were prepared. Acrylic resin emulsion 1: pH 4.5, manufactured by Aica Kogyo Co., Ltd., product name: Ultrasol N-80 Acrylic resin emulsion 2: pH 8.5, weight average molecular weight (Mw) 100,000, components (monomers: methyl methacrylate (MMA) 70% by mass, butyl methacrylate (BMA) 5% by mass, butyl acrylate (BA) 25% by mass, emulsifier: Aqualon BC-10 manufactured by Daiichi Kogyo Co., Ltd.) Acrylic resin emulsion 3: pH 4.5, weight average molecular weight (Mw) 7,000, components (monomer: MMA 50% by mass, ethyl acrylate (EA) 50% by mass), emulsifier: Daiichi Kogyo Co., Ltd., Hitenol NF-13) Acrylic resin emulsion 4: pH 4.5, weight average molecular weight (Mw) 15,000, components (monomer: MMA 50% by mass, EA 50% by mass, emulsifier: Hitenol NF-13) Dispersant: Surfactant, manufactured by Evonik Japan Co., Ltd., product name: ZetaSperse 2500 Defoamer: A mixture of mineral oil, polyether, silica, water, etc., manufactured by San Nopco Ltd., product name: SN Defoamer 777 Flame retardant 1: Aluminum diethylphosphinate, Clariant Japan Co., Ltd., product name: EXOLIT OP930 Flame retardant 2: Ammonium polyphosphate, manufactured by Clariant Japan Co., Ltd., product name: EXOLIT AP422 pH adjuster 1: 5% hydrochloric acid solution, pH 0.3 pH adjuster 2: 5% ammonia water, pH 11.3

[0049] [Examples 1 to 11, Comparative Examples 1 to 5] <Preparation of Water-Based Coating Composition> According to the formulations shown in Tables 1 to 3, coating compositions were produced according to the following procedures (1) to (3). (1) The specified amounts of water, resin, dispersant, and defoamer shown in Tables 1 to 3 were added in that order to a 250 ml inner coating can, and then mixed uniformly with a disperser for 10 to 15 minutes. (2) Next, the specified amounts of each of the flame retardants shown in Tables 1 to 3 were gradually added to the can while stirring with a disperser, and mixed for 10 to 15 minutes to ensure uniform mixing. (3) If necessary, the specified amounts of pH adjusters shown in Tables 1 to 3 were added to the cans and mixed, and the pH values ​​were confirmed using a pH meter (HORIBA Corporation, model number: LAQUA twin-pH-11) to produce coating compositions having the pH values ​​shown in Tables 1 to 3.

[0050] [Table 1]

[0051] [Table 2]

[0052] [Table 3]

[0053] <Evaluation> [Flame retardancy (combustion test)] Each coating composition of the Examples and Comparative Examples was diluted with 75% water and applied to a siding board at a coating amount of 50 g / m 2 The test plate with the coating was then spray-painted with a mixture of 100% ethyl alcohol and 100% ethyl alcohol, and then thoroughly dried to form a coating film. The test plate with the coating was then burned for 5 minutes using a cone calorimeter method in accordance with ISO 5660, and the flame retardancy was evaluated according to the following evaluation criteria. The evaluation results are shown in Tables 4 to 6. <Index for the cone calorimeter method> (1) Total calorific value is 8 MJ / m 2 The following is the result. (2) The maximum heat generation temperature is 200 kW / m for 10 seconds or more. 2 not exceed. (3) There are no cracks or holes that penetrate to the back surface and are detrimental to fire prevention. <Evaluation criteria> ○: All of the above criteria (1) to (3) were met. △: At least one of the above indicators (1) to (3) was met. ×: None of the above criteria (1) to (3) were met.

[0054] [water resistance] Each coating composition of the Examples and Comparative Examples was applied to a glass plate using a 2-mil doctor blade to a wet film thickness of 50 μm, followed by drying to form a coating film. Next, a plastic cap (diameter 25 mm) containing water was placed on the coating film, and the water was allowed to come into contact with the coating film for 24 hours. Thereafter, the appearance of the coating film was visually observed, and the water resistance was evaluated according to the following evaluation criteria. The evaluation results are shown in Tables 4 to 6. <Evaluation criteria> ◯: There was no abnormality in the appearance of the coating. △: There was a change in the gloss of the coating film. ×: The coating film was swollen or dissolved.

[0055] [Storage stability] Each of the coating compositions of the Examples and Comparative Examples was stored in an environment of 23° C. or 50° C., and the coating properties were checked after one month, and the storage stability was evaluated according to the following evaluation criteria. The evaluation results are shown in Tables 4 to 6. <Evaluation criteria> ○: No change was observed before and after storage. △: The flame retardant and other substances settled in the coating composition after storage, but the composition easily returned to the state before storage by stirring with a medicine spoon. It was judged that there was no problem in practical use. ×: The coating composition after storage had gelled, or the flame retardant or the like had settled in the coating composition after storage, and the composition did not return to its pre-storage state even when stirred with a medicine spoon.

[0056] [Table 4]

[0057] [Table 5]

[0058]

Table 6

Claims

1. A water-based coating composition comprising an acrylic resin emulsion (A) and a flame retardant (B), The flame retardant (B) contains a metal phosphinate, The aqueous coating composition has a pH of 2.5 or more and 4.5 or less.

2. 2. The water-based coating composition of claim 1, wherein the metal phosphinate comprises an aluminum dialkylphosphinate.

3. 2. The aqueous coating composition according to claim 1, wherein the pH of the acrylic resin emulsion (A) is 3.0 or more and 6.0 or less.

4. 2. The aqueous coating composition according to claim 1, wherein the pH of the aqueous coating composition is 3.0 or more and 4.2 or less.

5. 2. The aqueous coating composition according to claim 1, which is used for coating inorganic building materials.

6. A coating film formed from the coating composition according to any one of claims 1 to 5.

7. A coated substrate comprising a substrate and the coating film according to claim 6 formed on the substrate.

8. The coated substrate according to claim 7 , wherein the substrate is an inorganic building material.

9. A step of applying the coating composition according to any one of claims 1 to 5 onto a substrate; A step of drying the applied coating composition to form a coating film; A method for producing a substrate having a coating film, comprising:

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