Coating composition, building material, structural member, and method for manufacturing structural member

Abstract

To provide a coating composition which can improve flame retardancy of a base material and is quickly cured at ordinary temperature, a building material, a structural member, and a method for manufacturing a structural member.SOLUTION: A coating composition is provided, including water-soluble melamine resin (a), polycondensed phosphate (b), one or more (c) selected from a phosphoric acid, a boric acid, an ammonium salt and ammonia water, and a compound (d) having an amino group in a molecular structure. A structural member is provided, including a base material and a coated film formed on the surface of the base material, wherein the coated film includes a water-soluble melamine resin (A), polycondensed phosphate (B), one or more (C) selected from a phosphoric acid, a boric acid, an ammonium salt and ammonia, and polycondensate (D) of a compound having an amino group in the molecular structure and formaldehyde.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a coating composition, a building material, a structural member, and a method for producing a structural member. [Background technology]

[0002] One method of making wood flame retardant is to impregnate wood with a flame retardant. This method of impregnating wood with a flame retardant is disclosed in Patent Document 1. One method of making plastic flame retardant is to change the composition of the plastic. This method of changing the composition of the plastic is disclosed in Patent Document 2. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-137805 [Patent Document 2] Japanese Patent Application Laid-Open No. 2000-273298 Summary of the Invention [Problem to be solved by the invention]

[0004] Special equipment is required to penetrate the wood with a flame retardant. It also takes a lot of time and energy to penetrate the wood with a flame retardant. In the case of the method of changing the composition of the plastic, the composition of the plastic is limited.

[0005] It is conceivable that a coating composition can be applied to a flammable substrate such as wood or plastic to form a coating film, thereby making the flammable substrate flame retardant. Conventional coating compositions cure slowly at room temperature, and when applied to a vertical surface, the coating composition drips.

[0006] In one aspect of the present disclosure, it is preferable to provide a coating composition that can improve the flame retardancy of a substrate and cures quickly at room temperature, a building material, a structural member, and a method for producing a structural member. [Means for solving the problem]

[0007] One aspect of the present disclosure is a coating composition containing (a) a water-soluble melamine resin, (b) a condensation-polymerized phosphate ester, (c) one or more of phosphoric acid, boric acid, an ammonium salt, and aqueous ammonia, and (d) a compound having an amino group in its molecular structure.

[0008] A coating composition that is one aspect of the present disclosure can improve the flame retardancy of a substrate and cures quickly at room temperature. Another aspect of the present disclosure is a building material having a substrate and a coating film formed on a surface of the substrate, the coating film including (A) a water-soluble melamine resin, (B) a condensation-polymerized phosphate ester, (C) one or more of phosphoric acid, boric acid, an ammonium salt, and ammonia, and (D) a polycondensate of formaldehyde and a compound having an amino group in its molecular structure.

[0009] The building material according to another aspect of the present disclosure has high flame retardancy. Furthermore, when the building material according to another aspect of the present disclosure is produced, the coating film cures quickly at room temperature. Another aspect of the present disclosure is a structural member having a substrate and a coating film formed on a surface of the substrate, the coating film including (A) a water-soluble melamine resin, (B) a condensation-polymerized phosphate ester, (C) one or more of phosphoric acid, boric acid, an ammonium salt, and ammonia, and (D) a polycondensate of formaldehyde and a compound having an amino group in its molecular structure.

[0010] The structural member according to another aspect of the present disclosure has high flame retardancy. Furthermore, when the structural member according to another aspect of the present disclosure is produced, the coating film cures quickly at room temperature. Another aspect of the present disclosure is a method for producing a structural member by applying a coating composition to a surface of a substrate, the coating composition containing (a) a water-soluble melamine resin, (b) a condensation-polymerized phosphate ester, (c) one or more of phosphoric acid, boric acid, ammonium salt, and aqueous ammonia, and (d) a compound having an amino group in its molecular structure.

[0011] According to the method for producing a structural member according to another aspect of the present disclosure, a structural member having high flame retardancy can be produced. Furthermore, when producing a structural member, the coating film cures quickly at room temperature. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 2 is a cross-sectional view showing the configuration of a structural member. [Figure 2] FIG. 1 is a cross-sectional view showing a structural member in which the coating film has foamed and formed a heat insulating layer. DETAILED DESCRIPTION OF THE INVENTION

[0013] Exemplary embodiments of the present disclosure will now be described with reference to the drawings. 1. Coating composition (1-1)(a) Water-soluble melamine resin The coating composition of the present disclosure contains a water-soluble melamine resin. The water-soluble melamine resin can be produced, for example, by reacting aldehydes with melamine in the presence of an alkaline catalyst. Methods for producing water-soluble melamine resins are disclosed, for example, in Japanese Patent No. 257115, JP-A-51-114492, and JP-A-2006-124457.

[0014] Examples of water-soluble melamine resins include methylol melamine resins, alkoxylated methylol melamine resins, etc. Examples of methylol melamine resins include monomethylol melamine resins, dimethylol melamine resins, trimethylol melamine resins, etc. Examples of alkoxylated methylol melamine resins include methylol melamine resins, methylated methylol melamine resins, methoxymethylolated melamine resins, butylated methylol melamine resins, etc.

[0015] The alkoxylated methylol melamine resin may be completely alkoxylated, may have a residual methylol group, or may have a residual imino group. The coating composition of the present disclosure may also contain a copolymer of a water-soluble melamine resin and a phenolic resin or the like. Among the water-soluble melamine resins, methylol melamine resins are more preferred.

[0016] The coating composition of the present disclosure can be applied to the surface of a substrate to form a coating film. The substrate is, for example, a flammable substrate. When the coating composition contains a methylol melamine resin, the flame retardancy of the substrate and the transparency of the coating film become more pronounced. In this specification, transparency is not limited to complete transparency, and may be, for example, semi-transparent.

[0017] (1-2)(b) Polycondensed phosphate ester The coating composition of the present disclosure contains a condensation polymerized phosphate ester. The condensation polymerized phosphate ester is an ester obtained by a condensation reaction between polyphosphoric acid and an alcohol. Examples of the alcohol include aliphatic alcohols, glycols, polyhydric alcohols, and glycerin.

[0018] Examples of aliphatic alcohols include methanol, ethanol, butanol, and propanol. Examples of glycols include ethylene glycol and propylene glycol. Examples of polyhydric alcohols include pentaerythritol, dipentaerythritol, and tripentaerythritol.

[0019] The condensation polymerized phosphate ester is preferably a condensation polymerized phosphate ester obtained using a polyhydric alcohol. When the coating composition contains a condensation polymerized phosphate ester obtained using a polyhydric alcohol, the flame retardancy of the substrate and the transparency of the coating film become even more pronounced. The condensation polymerized phosphate ester is more preferably a condensation polymerized phosphate ester obtained using pentaerythritol. When the coating composition contains a condensation polymerized phosphate ester obtained using pentaerythritol, the flame retardancy of the substrate and the transparency of the coating film become even more pronounced.

[0020] The blending ratio of the condensation polymerization phosphate ester per 100 parts by mass of the water-soluble melamine resin is preferably 120 parts by mass or more and 350 parts by mass or less, more preferably 130 parts by mass or more and 200 parts by mass or less, and most preferably 170 parts by mass.

[0021] When the blending ratio of the condensation polymerization phosphate ester to 100 parts by mass of the water-soluble melamine resin is 120 parts by mass or more and 350 parts by mass or less, the flame retardancy of the substrate and the transparency of the coating film become more remarkable.When an excess of the condensation polymerization phosphate ester is mixed with the water-soluble melamine resin, the flame retardancy of the substrate and the transparency of the coating film become more remarkable.

[0022] (1-3)(c) component The coating composition of the present disclosure includes component (c). Component (c) includes one or more of phosphoric acid, boric acid, ammonium salt, and aqueous ammonia. Component (c) includes, for example, both phosphoric acid and boric acid. Examples of ammonium salts include ammonium phosphate salts and ammonium borate salts.

[0023] Ammonia gradually evaporates from the ammonium salt and aqueous ammonia, and the volatilized ammonia retards the hardening of the water-soluble melamine resin. The blending ratio of component (c) per 100 parts by mass of the water-soluble melamine resin is preferably 15 parts by mass or more and 90 parts by mass or less, more preferably 20 parts by mass or more and 50 parts by mass or less, and most preferably 31 parts by mass.

[0024] When the blending ratio of component (c) per 100 parts by mass of the water-soluble melamine resin is 15 parts by mass or more and 90 parts by mass or less, the flame retardancy of the substrate and the transparency of the coating film become more pronounced. When component (c) contains an excess of phosphoric acid or boric acid relative to the water-soluble melamine resin, the curing of the water-soluble melamine resin is accelerated.

[0025] Furthermore, when component (c) contains excess phosphoric acid or boric acid relative to the water-soluble melamine resin, the excess phosphoric acid or boric acid chemically bonds with the hydroxyl groups of the substrate, improving adhesion between the coating and the substrate. When the substrate is wood, the phosphoric acid or boric acid chemically bonds with the hydroxyl groups of cellulose. Furthermore, the excess phosphoric acid or boric acid chemically bonds with the water-soluble melamine resin decomposed by the heat of combustion during a fire, further enhancing the flame retardancy of the substrate. It is presumed that the excess phosphoric acid or boric acid chemically bonds with the hydroxyl groups produced by the thermal decomposition of the water-soluble melamine resin.

[0026] (1-4)(d) Compounds with an amino group in the molecular structure The coating composition of the present disclosure contains (d) a compound having an amino group in its molecular structure (hereinafter also referred to as component (d)). By including component (d) in the coating composition, the coating composition cures faster at room temperature. The faster the coating composition cures at room temperature, the less sagging occurs when the coating composition is applied to a vertical surface.

[0027] Examples of the component (d) include urea, melamine, aliphatic amines, aromatic amines, and heterocyclic amines. Examples of aliphatic amines include methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethylenediamine, triethanolamine, N,N-diisopropylethylamine, tetramethylethylenediamine, hexamethylenediamine, spermidine, spermine, and amantadine.

[0028] Examples of aromatic amines include aniline, phenethylamine, toluidine, catecholamine, and 1,8-bis(dimethylamino)naphthalene. Examples of heterocyclic amines include pyrrolidine, piperidine, piperazine, morpholine, quinuclidine, 1,4-diazabicyclo[2.2.2]octane, pyrrole, pyrazole, imidazole, pyridine, pyridazine, pyrimidine, pyrazine, oxazole, thiazole, and 4-dimethylaminopyridine.

[0029] Component (d) is preferably a compound having two or more amino groups or urea. Examples of component (d) having two or more amino groups include ethylenediamine and hexamethylenediamine. When the coating composition contains a compound having two or more amino groups or urea as component (d), the coating composition cures more quickly at room temperature.

[0030] The reason why the coating composition cures more rapidly at room temperature is presumed to be because the polycondensation product of component (d) and formaldehyde remaining in the water-soluble melamine resin reduces the fluidity of the coating composition. The polycondensation product of component (d) and formaldehyde is component (D), which will be described later.

[0031] The blending ratio of component (d) per 100 parts by mass of the water-soluble melamine resin is preferably 0.05 to 5 parts by mass, more preferably 0.5 to 5 parts by mass, and particularly preferably 2.5 parts by mass. When the blending ratio of component (d) per 100 parts by mass of the water-soluble melamine resin is 0.05 to 5 parts by mass, the curing of the coating composition at room temperature becomes even faster.

[0032] (1-5)(e) Kaolin The coating composition of the present disclosure further contains, for example, (e) kaolin. As the kaolin, halloysite (Al2Si2O5(OH)4·2H2O) is preferred. Halloysite has a tubular crystal structure. Halloysite has siloxane (-Si-O-Si-) on the outside and aluminol (-Al-O-Al-) on the inside. Therefore, the surface of halloysite is acidic.

[0033] When the coating composition contains kaolin, the coating composition hardens faster. When the coating composition contains halloysite, the coating composition hardens even faster. The particle size of the kaolin is preferably 1 μm or more and 10 μm or less. When the particle size of the kaolin is 1 μm or more and 10 μm or less, the coating composition hardens more quickly.

[0034] The blending ratio of kaolin per 100 parts by mass of water-soluble melamine resin is preferably from 20 to 250 parts by mass, more preferably from 50 to 200 parts by mass, and most preferably from 150 to 180 parts by mass. When the blending ratio of kaolin per 100 parts by mass of water-soluble melamine resin is 250 parts by mass or less, it is possible to prevent the coating film from becoming cloudy. (1-6)(f) Glass fiber The coating composition of the present disclosure further contains, for example, (f) glass fiber. When the coating composition contains glass fiber, the shape retention of the foam layer after heat foaming is improved. The diameter of the glass fiber is preferably 5 μm or more and 15 μm or less. The length of the glass fiber is preferably 10 μm or more and 200 μm or less, and more preferably 20 μm or more and 50 μm or less. The value obtained by dividing the length of the glass fiber by the diameter of the glass fiber is defined as the aspect ratio of the glass fiber. The aspect ratio of the glass fiber is preferably 1.5 or more and 5.5 or less.

[0035] (1-7) Other ingredients The coating composition of the present disclosure can contain additives, pigments, etc. used in conventional coatings, to the extent that the flame retardancy, transparency of the coating film, and curing speed of the coating film are not significantly impaired. Examples of additives include thickeners, pH adjusters, dispersants, wetting agents, preservatives, dyes, antifoaming agents, pigments, etc.

[0036] Examples of thickeners include polyvinyl alcohol, urethane-modified polyether, and carboxymethyl cellulose. Examples of pH adjusters include aqueous ammonia and amines. Examples of pigments include inorganic pigments, organic pigments, and extender pigments. Examples of inorganic pigments include carbon black, titanium oxide, and iron oxide. Examples of organic pigments include quinacridone and azo pigments. Examples of extender components include silica, barium sulfate, talc, and mica.

[0037] The coating composition of the present disclosure contains, for example, an acid. The acid accelerates the curing of the water-soluble melamine resin. Examples of the acid include sulfonic acid and carboxylic acid. Examples of the sulfonic acid include p-toluenesulfonic acid. Examples of the carboxylic acid include acetic acid, citric acid, maleic acid, and acrylic acid.

[0038] The coating composition of the present disclosure contains, for example, components of an intumescent fire-resistant coating, such as ammonium polyphosphate, melamine, and polyhydric alcohols, to the extent that the transparency of the coating film is not significantly impaired. Examples of the components of the intumescent fire-resistant coating include ammonium polyphosphate, melamine, and polyhydric alcohols, such as pentaerythritol.

[0039] (1-8) Form of coating composition The coating composition of the present disclosure may be in the form of a two-component coating, for example, composed of a first component and a second component. The first component contains a water-soluble melamine resin. The second component contains a condensation-polymerized phosphate ester and component (c). The first component and the second component are mixed before use. When the coating composition of the present disclosure is in the form of a two-component coating, the coating composition has high storage stability.

[0040] Component (d) is preferably contained in the second part and not in the first part. When component (d) is contained in the second part and not in the first part, the storage stability of the coating composition is even higher. 2. How to use the coating composition The coating composition of the present disclosure is used, for example, as follows: When the coating composition is in the form of a two-component coating, the first and second components are mixed using a mixer. Next, the coating composition is applied to the surface of the substrate. This application is referred to as the first application.

[0041] The substrate may be, for example, a flammable substrate. The flammable substrate may be, for example, wood. An example of wood is cedar lumber having a thickness of 12 mm, a width of 100 mm, and a length of 2000 mm. The coating composition may be applied, for example, with a brush or a roller. The coating amount of the coating composition may be, for example, 300 g / m. 2 is.

[0042] After the first application, the sample is left at room temperature for 1 hour. Then, the sample is forced to dry at 50°C for 16 hours. Next, the coating composition is applied again. This application is the second application. The application method and amount applied for the second application are the same as for the first application. After the second application, the sample is left at room temperature for 1 hour. Then, the sample is forced to dry at 50°C for 16 hours.

[0043] Next, a matte paint containing an acrylic resin emulsion is applied using an air spray. The amount of the matte paint applied is, for example, 100 g / m 2 Next, it is dried at 50°C for 10 minutes. Through these steps, a flame-retardant wooden building material can be obtained.

[0044] The substrate is not limited to wood and can be selected arbitrarily. Examples of the substrate include plastic, wooden building materials, paper, cloth, etc. Examples of plastic include polyethylene resin, polypropylene resin, acrylic resin, phenolic resin, vinyl chloride resin, and expanded polystyrene resin. Examples of wooden building materials include lumber, laminated lumber, plywood, laminated veneer lumber (LVL), cross-laminated timber (CLT), and medium-density fiberboard (MDF). The form of the substrate is not particularly limited. Examples of the form of the substrate include a pillar, a board, a sheet, and a cloth.

[0045] Examples of the substrate include wooden structural members, such as pillars, beams, walls, and floors. The pillar may be, for example, a rectangular pillar. The cross-sectional shape of the rectangular pillar in a cross section perpendicular to the longitudinal direction is, for example, a square. The length of one side of the square is, for example, 90 mm or more and 1100 mm or less. An example of a beam is a rectangular beam. The cross-sectional shape of a rectangular beam in a cross section perpendicular to the longitudinal direction is, for example, a rectangle. The length of one side of the rectangle is, for example, 90 mm or more and 800 mm or less. The length of the side adjacent to the one side is, for example, 90 mm or more and 1200 mm or less. The length of the rectangular beam is not particularly limited, but is, for example, 3000 mm or more and 10000 mm or less. The shape of the wall is, for example, a rectangle. The length of the short side of the rectangle is, for example, 3000 mm or less. The length of the short side of the rectangle is, for example, 500 mm or more. The length of the long side of the rectangle is, for example, 12000 mm or less. The length of the long side of the rectangle is, for example, 2000 mm or more. The substrate may be, for example, a piece of wood with a plate- or sheet-like member attached to its surface. Examples of the plate- or sheet-like member include gypsum board, fireproof sheet, decorative material, etc.

[0046] The tool used to apply the coating composition may be a tool other than a roller. As the tool used to apply the coating composition, a tool used to apply a normal coating can be used. Examples of the tool used to apply the coating composition include a brush, a spatula, a spray, and a roll coater.

[0047] The coating amount of the coating composition can be set arbitrarily depending on the flame retardancy required. For example, when the coating amount is 50 kW / m according to the cone calorimeter method specified in ISO 5660-1, 2 When cedar lumber is heated for 10 minutes at a radiation intensity of 8MJ / m 2 To achieve this, the coating amount should be 300g / m 2 ~1000g / m 2 Preferably, it is 400 g / m 2 ~600g / m 2 It is more preferable that the total heat generation amount when heated for 5 minutes under the above conditions is 8MJ / m 2 To achieve this, the coating amount must be 100g / m 2 ~400g / m 2 It is preferable that:

[0048] After application of the coating composition, the drying temperature is preferably 80° C. or lower. When forced drying is performed, the drying temperature is 35° C. to 70° C., more preferably 45 to 60° C. Natural drying may be performed instead of forced drying.

[0049] The drying time after application of the coating composition can be shortened or extended as necessary. The time left at room temperature before forced drying is preferably 30 minutes to 24 hours, more preferably 1 hour to 16 hours. When the drying temperature in forced drying is 60°C or lower, forced drying may be performed immediately after application without leaving it at room temperature.

[0050] The purpose of applying a matte paint is to impart a design. Paint intended to impart a design is called a decorative paint. In decorative paint, a glossy paint may be used instead of a matte paint. In decorative paint, paints that do not significantly impair the visibility of the substrate can be appropriately selected and used, not limited to paints containing acrylic resin emulsions.

[0051] The paint used in the decorative coating may be a paint containing a synthetic resin solution or a synthetic resin aqueous solution instead of a synthetic resin emulsion. The paint used in the decorative coating is not limited to acrylic resin, and may be a paint containing any synthetic resin such as urethane resin, epoxy resin, vinyl acetate resin, or olefin resin. A commercially available clear paint may be used in the decorative coating. It is preferable to use a paint containing an olefin resin solution in the decorative coating. Decorative coating does not have to be performed.

[0052] 3. Effects of the coating composition (3-1) When the coating composition of the present disclosure is applied to the surface of a substrate, the flame retardancy of the substrate increases. The reason for this is presumed to be as follows. Here, we will explain an example in which the coating composition of the present disclosure contains phosphoric acid as component (c).

[0053] When a substrate coated with the coating composition of the present disclosure and then coated with a decorative coating is exposed to the heat of combustion during a fire, the coating film of the decorative coating on the outermost surface burns within a few seconds to several tens of seconds. Next, foaming of the coating film of the coating composition of the present disclosure begins, and a condensation polymerization reaction between the condensation polymerization phosphate ester and phosphoric acid occurs, forming a black foam insulation layer. When the substrate is wood, it is believed that phosphoric acid also undergoes a condensation polymerization reaction with the hydroxyl groups of cellulose, the main component of wood. The foam insulation layer suppresses the conduction of combustion heat during a fire, delaying the time it takes for the wood surface to reach its ignition temperature. The ignition temperature of wood is 250 to 270°C. As a result, the flame retardancy of the substrate is improved.

[0054] (3-2) The coating composition of the present disclosure contains component (d) along with other components. Therefore, the coating composition cures quickly at room temperature. Faster curing of the coating composition at room temperature reduces sagging when applied to a vertical surface.

[0055] 4. Composition of building materials The building material of the present disclosure has a substrate and a coating film formed on the surface of the substrate. Examples of the substrate include those listed above in the section "2. Method of using the coating composition."

[0056] The coating film contains (A) a water-soluble melamine resin, (B) a condensation-polymerized phosphate ester, (C) one or more of phosphoric acid, boric acid, ammonium salt, and ammonia (hereinafter also referred to as component (C)), and (D) a polycondensate of a compound having an amino group in its molecular structure and formaldehyde (hereinafter also referred to as component (D)).

[0057] The (A) water-soluble melamine resin is, for example, the same as the (a) water-soluble melamine resin contained in the coating composition. (B) Polycondensation polymerized phosphate ester is, for example, the same as (b) Polycondensation polymerized phosphate ester contained in the coating composition.

[0058] In the coating film, the blending ratio of the condensation polymerization phosphate ester per 100 parts by mass of the water-soluble melamine resin is preferably 120 parts by mass or more and 350 parts by mass or less, more preferably 130 parts by mass or more and 200 parts by mass or less, and most preferably 170 parts by mass.

[0059] When the blending ratio of the condensation polymerization phosphate ester to 100 parts by mass of the water-soluble melamine resin in the coating film is 120 parts by mass or more and 350 parts by mass or less, the flame retardancy of the building material and the transparency of the coating film become more pronounced.When an excess of the condensation polymerization phosphate ester is mixed with the water-soluble melamine resin, the flame retardancy of the building material and the transparency of the coating film become more pronounced.

[0060] Component (C) is basically the same as component (c) contained in the coating composition, except that one option for component (C) is ammonia rather than aqueous ammonia. In the coating film, the blending ratio of component (C) per 100 parts by mass of the water-soluble melamine resin is preferably 15 parts by mass or more and 90 parts by mass or less, more preferably 20 parts by mass or more and 50 parts by mass or less, and most preferably 31 parts by mass.

[0061] When the blending ratio of component (C) to 100 parts by mass of water-soluble melamine resin in the coating film is 15 to 90 parts by mass, the flame retardancy of the building material and the transparency of the coating film become more pronounced. When component (C) contains an excess of phosphoric acid or boric acid relative to the water-soluble melamine resin, the curing of the water-soluble melamine resin is accelerated.

[0062] Furthermore, when component (C) contains excess phosphoric acid or boric acid relative to the water-soluble melamine resin, the excess phosphoric acid or boric acid chemically bonds with the hydroxyl groups of the substrate, improving adhesion between the coating and the substrate. When the substrate is wood, the phosphoric acid or boric acid chemically bonds with the hydroxyl groups of cellulose. Furthermore, the excess phosphoric acid or boric acid chemically bonds with the water-soluble melamine resin decomposed by the heat of combustion during a fire, further enhancing the flame retardancy of the building material. It is presumed that the excess phosphoric acid or boric acid chemically bonds with the hydroxyl groups generated by the thermal decomposition of the water-soluble melamine resin.

[0063] The compound having an amino group in its molecular structure in component (D) is, for example, the same as component (d) contained in the coating composition. In the coating film, the blending ratio of component (D) per 100 parts by mass of water-soluble melamine resin is preferably from 0.05 to 5 parts by mass, more preferably from 0.5 to 5 parts by mass. When the blending ratio of component (D) per 100 parts by mass of water-soluble melamine resin is from 0.05 to 5 parts by mass, the coating film hardens more rapidly at room temperature when producing building materials.

[0064] The coating film contains, for example, (E) kaolin. (E) Kaolin is, for example, the same as the component (e) contained in the coating composition. In the coating film, the blending ratio of kaolin per 100 parts by mass of water-soluble melamine resin is preferably from 20 to 250 parts by mass, more preferably from 50 to 200 parts by mass, and most preferably from 150 to 180 parts by mass. When the blending ratio of kaolin per 100 parts by mass of water-soluble melamine resin is 250 parts by mass or less, the coating film can be prevented from becoming cloudy.

[0065] The coating film contains, for example, (F) glass fibers. The (F) glass fibers are, for example, the same as the component (f) contained in the coating composition. The coating film may contain, for example, "other components" in the coating composition. The coating film is formed, for example, by applying the coating composition of the present disclosure. The building materials of the present disclosure are highly flame-retardant. In addition, because the coating film contains component (D), the coating film cures quickly at room temperature when the building materials are produced.

[0066] 5. Structure of structural members The structural member of the present disclosure has a substrate and a coating film formed on the surface of the substrate. Examples of structural members include pillars, beams, walls, and floors. Examples of substrates include those listed in the above section "2. Method of using the coating composition." The pillar may be, for example, a rectangular pillar. The cross-sectional shape of the rectangular pillar in a cross section perpendicular to the longitudinal direction is, for example, a square. The length of one side of the square is, for example, 90 mm or more and 1100 mm or less. An example of a beam is a rectangular beam. The cross-sectional shape of a rectangular beam in a cross section perpendicular to the longitudinal direction is, for example, a rectangle. The length of one side of the rectangle is, for example, 90 mm or more and 800 mm or less. The length of the side adjacent to the one side is, for example, 90 mm or more and 1200 mm or less. The length of the rectangular beam is not particularly limited, but is, for example, 3000 mm or more and 10000 mm or less. The shape of the wall is, for example, a rectangle. The length of the short side of the rectangle is, for example, 3000 mm or less. The length of the short side of the rectangle is, for example, 500 mm or more. The length of the long side of the rectangle is, for example, 12000 mm or less. The length of the long side of the rectangle is, for example, 2000 mm or more.

[0067] The coating film contains (A) a water-soluble melamine resin, (B) a condensation-polymerized phosphate ester, (C) a component, and (D) a component. The (A) water-soluble melamine resin is, for example, the same as the (a) water-soluble melamine resin contained in the coating composition.

[0068] (B) Polycondensation polymerized phosphate ester is, for example, the same as (b) Polycondensation polymerized phosphate ester contained in the coating composition. In the coating film, the blending ratio of the condensation polymerization phosphate ester per 100 parts by mass of the water-soluble melamine resin is preferably 120 parts by mass or more and 350 parts by mass or less, more preferably 130 parts by mass or more and 200 parts by mass or less, and most preferably 170 parts by mass.

[0069] When the blending ratio of the condensation polymerization phosphate ester to 100 parts by mass of the water-soluble melamine resin in the coating film is 120 parts by mass or more and 350 parts by mass or less, the flame retardancy of the structural member and the transparency of the coating film become more pronounced.When an excess of the condensation polymerization phosphate ester is mixed with the water-soluble melamine resin, the flame retardancy of the structural member and the transparency of the coating film become more pronounced.

[0070] Component (C) is basically the same as component (c) contained in the coating composition, except that one option for component (C) is ammonia rather than aqueous ammonia. In the coating film, the blending ratio of component (C) per 100 parts by mass of the water-soluble melamine resin is preferably 15 parts by mass or more and 90 parts by mass or less, more preferably 20 parts by mass or more and 50 parts by mass or less, and most preferably 31 parts by mass.

[0071] When the blending ratio of component (C) to 100 parts by mass of water-soluble melamine resin in the coating film is 15 to 90 parts by mass, the flame retardancy of the structural member and the transparency of the coating film become more pronounced. When component (C) contains an excess of phosphoric acid or boric acid relative to the water-soluble melamine resin, the curing of the water-soluble melamine resin is accelerated.

[0072] Furthermore, when component (C) contains excess phosphoric acid or boric acid relative to the water-soluble melamine resin, the excess phosphoric acid or boric acid chemically bonds with the hydroxyl groups of the substrate, improving adhesion between the coating and the substrate. When the substrate is wood, the phosphoric acid or boric acid chemically bonds with the hydroxyl groups of cellulose. Furthermore, the excess phosphoric acid or boric acid chemically bonds with the water-soluble melamine resin decomposed by the heat of combustion during a fire, further enhancing the flame retardancy of the structural member. It is presumed that the excess phosphoric acid or boric acid chemically bonds with the hydroxyl groups produced by the thermal decomposition of the water-soluble melamine resin.

[0073] The compound having an amino group in its molecular structure in component (D) is, for example, the same as component (d) contained in the coating composition. In the coating film, the blending ratio of component (D) per 100 parts by mass of water-soluble melamine resin is preferably from 0.05 to 5 parts by mass, more preferably from 0.5 to 5 parts by mass. When the blending ratio of component (D) per 100 parts by mass of water-soluble melamine resin is from 0.05 to 5 parts by mass, the coating film hardens more rapidly at room temperature when producing structural parts.

[0074] The coating film contains, for example, (E) kaolin. (E) Kaolin is, for example, the same as the component (e) contained in the coating composition. In the coating film, the blending ratio of kaolin per 100 parts by mass of water-soluble melamine resin is preferably from 20 to 250 parts by mass, more preferably from 50 to 200 parts by mass, and most preferably from 150 to 180 parts by mass. When the blending ratio of kaolin per 100 parts by mass of water-soluble melamine resin is 250 parts by mass or less, the coating film can be prevented from becoming cloudy. The coating film contains, for example, (F) glass fibers. The (F) glass fibers are, for example, the same as the component (f) contained in the coating composition.

[0075] The coating film may contain, for example, "other components" in the coating composition. The coating film is formed, for example, by applying the coating composition of the present disclosure. The structural member 1 has, for example, the form shown in Figure 1. The structural member 1 is a long pillar. The shape of the structural member 1 in a cross section perpendicular to the longitudinal direction of the structural member 1 is rectangular. Figure 1 shows the cross section perpendicular to the longitudinal direction. The structural member 1 has a base material 3 made of wood and a coating film 5. The coating film 5 is formed on the surface of the base material 3. The outer peripheral portion of the base material 3 is a burn margin 7.

[0076] When a fire breaks out and the coating film 5 is heated, the coating film 5 foams and forms a heat insulating layer 9, as shown in Figure 2. The heat insulating layer 9 suppresses combustion of the substrate 3. Because the heat insulating layer 9 is formed, the thickness of the burn margin 7 can be reduced while maintaining the flame retardancy of the structural member 1. As a result, the cross section of the structural member 1 can be reduced while maintaining the flame retardancy of the structural member 1.

[0077] The structural members of the present disclosure have high flame retardancy. Furthermore, because the coating film contains component (D) along with other components, the coating film cures quickly at room temperature when the structural member is produced. 6. Manufacturing method of structural members In the method for producing a structural member of the present disclosure, a coating composition is applied to the surface of a substrate. Examples of structural members include pillars, beams, walls, and floors. Examples of substrates include those listed in the above section "2. Method for using the coating composition."

[0078] The coating composition is as explained above in the section "1. Constitution of the coating composition." The coating composition can be applied by, for example, the method mentioned above in the section "2. Method of using the coating composition." Structural members manufactured by the method for manufacturing a structural member of the present disclosure include, for example, those listed in the above section "5. Configuration of structural member."

[0079] The structural members produced by the method for producing a structural member of the present disclosure have high flame retardancy. Furthermore, since the coating composition contains component (d) along with other components, the coating composition cures quickly at room temperature when producing the structural member.

[0080] 7. Working Example (7-1) Manufacture of paint compositions and decorative paints The coating compositions of Examples 1 to 13 and Comparative Examples 1 to 3 were produced by mixing the components listed in the "Coating Composition" row in Tables 1 and 2 with water. The units of the blending amounts of the components listed in the "Coating Composition" row are parts by mass. The components listed in the "Coating Composition" row are non-volatile components. In each Example and Comparative Example, the mass ratio of the total non-volatile components to the total mass of the coating composition was 64 mass%, and the mass ratio of water was 36 mass%.

[0081] In addition, the decorative paints of Examples 1 to 13 and Comparative Examples 1 to 3 were produced by mixing the components listed in the "Design Paint" row in Tables 1 and 2 with water. The units of the blending amounts of the components listed in the "Design Paint" row are parts by mass. The components listed in the "Design Paint" row are non-volatile components. In each Example and Comparative Example, the mass ratio of the total non-volatile components to the total mass of the decorative paint was 64 mass%, and the mass ratio of water was 36 mass%.

[0082] [Table 1]

[0083] [Table 2] (7-2) Manufacturing of structural components

[0084] In each of the examples and comparative examples, a structural member was manufactured. The manufacturing method of the structural member was as follows. A coating composition was applied to the surface of a substrate using a brush. The substrate was a plate-shaped member. The material of the substrate was the material described in the row of "Type of substrate" in Tables 1 and 2. The thickness of the substrate was the thickness described in the row of "Thickness of substrate" in Tables 1 and 2. The coating amount of the coating composition is shown in the "Coating composition" column of Tables 1 and 2, under "Coating amount (non-volatile content) g / m 2 The coating amount was as shown in the "." line. The coating was then dried at 23°C and 50% RH to form a coating film. The coating film basically had the non-volatile components of the coating composition. However, component (d) contained in the coating composition became component (D) through a chemical reaction.

[0085] Next, a decorative paint was applied to the surface of the formed coating film using a brush. The amount of decorative paint applied was determined by the "Amount applied (non-volatile matter) g / m" column in the "Designer paint" column in Tables 1 and 2. 2 The coating amount was as described in the line "." Then, the coating was dried under conditions of 23°C and 50% RH to form a coating film.

[0086] The structural member was completed through the above process. The structural member had a substrate and a coating film formed on the surface of the substrate. The coating film was a laminated coating film consisting of a first coating film formed by applying a coating composition and a second coating film formed by applying a decorative paint. The first coating film contained (A) a water-soluble melamine resin, (B) a condensation-polymerized phosphate ester, (C) one or more of phosphoric acid, boric acid, ammonium salt, and ammonia, (D) a polycondensate of a compound having an amino group in its molecular structure and formaldehyde, and kaolin.

[0087] (7-3) Evaluation of coating compositions and structural components The coating compositions and structural members of each Example and Comparative Example were evaluated as follows. (i) Evaluation of coating hardening The coating composition was applied to the surface of wood. The type of wood was cedar. The coating amount was 500 g / m 2 After application, the coating was left at 23°C and 50% RH. 16 hours after application, the evaluator touched the surface of the coating with his / her finger. The curing of the coating was evaluated according to the following criteria. The evaluation results are shown in the "Evaluation of Coating" row in Tables 1 and 2.

[0088] ◎: The coating film is not sticky. ◯: The coating film is sticky, but does not move when touched with a finger. △: The coating film moves.

[0089] ×: Paint sticks to fingers. In each example, the coating film cured quickly, whereas in each comparative example, the coating film cured slowly. (ii) Measurement of total heat release and maximum heat release rate The specimens for evaluation were plate-shaped members cut out from structural members. The specimens were 99 mm long, 99 mm wide, and 30 to 50 mm thick. The main surfaces of the specimens were provided with a coating film formed by applying a coating composition. Using the cone calorimeter method specified in ISO5660-1, the test specimen is subjected to 50kW / m 2 The total heat generation rate and maximum heat generation rate were measured when the sample was heated for 10 minutes at a radiation intensity of 7 MJ / m. The measurement results of the total heat generation rate are shown in the "Total heat generation rate" column in Tables 1 and 2. "〇" indicates that the total heat generation rate was 7 MJ / m 2 "△" means that the total calorific value was less than 7MJ / m 2 More than 8MJ / m 2 "×" means that the total calorific value was 8MJ / m or less. 2 It means that it has exceeded

[0090] The measurement results of the maximum heat release rate are shown in the "Maximum heat release rate" row in Tables 1 and 2. "〇" indicates 200 kW / m2 This means that the time it took to exceed 200kW / m was less than 8 seconds. 2 This means that the time it took to exceed 200kW / m was between 8 and 10 seconds. 2 This means that the time that the value exceeds the threshold exceeds 10 seconds.

[0091] In each example, the total heat release amount and the maximum heat release rate were small. In comparative examples 1 and 2, the total heat release amount and the maximum heat release rate were large. 8. Other Embodiments Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and can be implemented in various modified forms. [Explanation of symbols]

[0092] 1...structural member, 3...substrate, 5...coating film, 7...burning margin, 9...insulating layer

Claims

1. (a) a water-soluble melamine resin; (b) a condensation-polymerized phosphate ester; (c) one or more of phosphoric acid and boric acid; and (d) urea or melamine, A coating composition in which the blending ratio of the component (c) per 100 parts by mass of the component (a) is 15 parts by mass or more and 90 parts by mass or less.

2. The coating composition of claim 1, (e) A coating composition further comprising kaolin.

3. The coating composition according to claim 1 or 2, (f) A coating composition further containing glass fibers.

4. A substrate and a coating film formed on the surface of the substrate, The coating film contains (A) a water-soluble melamine resin, (B) a condensation-polymerized phosphate ester, (C) one or more of phosphoric acid and boric acid, and (D) a polycondensate of urea or melamine with formaldehyde, A building material in which the blending ratio of the component (C) per 100 parts by mass of the component (A) is 15 parts by mass or more and 90 parts by mass or less.

5. A substrate and a coating film formed on the surface of the substrate, The coating film contains (A) a water-soluble melamine resin, (B) a condensation-polymerized phosphate ester, (C) one or more of phosphoric acid and boric acid, and (D) a polycondensate of urea or melamine with formaldehyde, A structural member in which the blending ratio of the component (C) per 100 parts by mass of the component (A) is 15 parts by mass or more and 90 parts by mass or less.

6. A method for manufacturing a structural member by applying a coating composition to a surface of a substrate, The coating composition contains (a) a water-soluble melamine resin, (b) a condensation-polymerized phosphate ester, (c) one or more of phosphoric acid and boric acid, and (d) urea or melamine, A method for manufacturing a structural member, wherein the blending ratio of the component (c) per 100 parts by mass of the component (a) is 15 parts by mass or more and 90 parts by mass or less.

7. A method for manufacturing a structural member according to claim 6, comprising: The coating composition further contains (e) kaolin. Manufacturing method of structural members.

8. A method for manufacturing a structural member according to claim 6 or 7, The coating composition further contains (f) glass fibers. Manufacturing method of structural members.

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