Water-based foamed refractory coating composition

Abstract

To propose an aqueous foamable fireproof coating composition excellent in both of water proofness of a coated film in a normal period and fire proofness of an expanded coated film generated in a fire disaster.SOLUTION: The aqueous foamable fireproof coating composition includes: a polyvalent metal compound (A) containing a metal element which can take an ion atomic valence of bivalent or more; a resin (B) having a functional group capable of forming a metal cross linking with the metal element containing the polyvalent metal compound; a char-forming auxiliary material (C); and water. A method of coating a substrate includes coating a substrate surface with the aqueous foamable fireproof coating composition. A method of protecting a structure from heat and a fire disaster includes coating a substrate surface with the aqueous foamable fireproof coating composition.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an aqueous foaming refractory coating composition containing water as a diluent medium.

Background Art

[0002] Since iron rapidly loses its strength near 500°C, in the event of a fire, a steel-frame structure collapses, making evacuation and firefighting activities impossible. Therefore, in order to maintain the strength for a specified time even during a fire, it is obligatory by the Building Standards Law to apply a refractory coating with heat insulation properties to the steel frame of the structure. As this refractory coating material, there are rock wool refractory coatings and foaming refractory paints. Rock wool refractory coatings are inexpensive and widely distributed in the market, but they require a thickness of 1 cm to several cm to exhibit refractory performance, and there is a problem that spraying work is difficult.

[0003] On the other hand, a foaming refractory paint is a coating material that expands the coating film due to the temperature rise during a fire and exhibits heat insulation properties. Unlike rock wool, the refractory coating using a foaming refractory paint is a thin film during normal times and does not damage the shape of the structure itself. During a fire, it expands and carbonizes, and a fire-resistant foamed layer called char suppresses the temperature rise of iron and can delay the collapse of the structure.

[0004] As this foaming refractory paint, the applicant has proposed in Patent Document 1 a foaming refractory paint containing a hydrolyzable silyl group-containing resin, a plasticizer, a foaming agent, and a carbonizing agent. In this paint, thick coating is easy, and a protective coating film excellent in various physical properties such as quick drying property, internal curing property, and water resistance can be obtained, and in the situation of a fire, a foamed layer excellent in fire resistance can be formed.

[0005] However, the foaming refractory paint described in Patent Document 1 contains an organic solvent as a diluent medium, and there is a problem of odor when it is applied in hospitals, schools, etc. In addition, there are problems such as the inability to carry out parallel work with electrical work due to the scattering of organic solvents, and the demand for an aqueous foaming refractory paint using water as a diluent medium is increasing.

[0006] As an aqueous foaming refractory paint, for example, Patent Document 2 discloses a paint composition containing an acrylic resin emulsion, a polyhydric alcohol, a foaming agent, a flame retardant dehydrating agent, and an alkali thickening type emulsion. Although this paint composition is excellent in painting workability and fire resistance, it has a problem that its application range is limited because the water resistance of the paint film is insufficient.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0008] For refractory paints, physical properties such as painting workability and water resistance during normal times, and fire resistance during a fire are required. In order to enhance the physical properties such as the water resistance of the paint film during normal times, a method of crosslinking the resin forming the paint film is effective. However, when this method is used, it becomes difficult for the paint film to expand during a fire, and sufficient fire resistance is often not obtained. Thus, the water resistance of the paint film during normal times and the fire resistance during a fire are in a trade-off relationship. Moreover, since a paint film formed from an aqueous paint is difficult to form a film compared to an organic solvent-based paint, an effective method for achieving both has not been found.

[0009] An object of the present invention is to propose an aqueous foaming refractory paint composition in which both the water resistance of the paint film during normal times and the fire resistance of the expanded paint film generated during a fire are good without restricting the application range of the foaming refractory paint.

Means for Solving the Problems

[0010] The inventors of the present invention have intensively studied the above problems. As a result, according to the metal crosslinking formed by the metal element contained in the polyvalent metal compound and the functional group in the resin, water resistance can be ensured by a dense crosslinked structure during normal times, and at high temperatures such as during a fire, the crosslinked structure decomposes, and a coating film is formed that exhibits high fire resistance without hindering expansion.

[0011] That is, the present invention is Item 1 An aqueous foaming fire-resistant coating composition containing a polyvalent metal compound (A) containing a metal element capable of taking a divalent or higher ionic valence, a resin (B) having a functional group capable of forming a metal crosslink with the metal element contained in the polyvalent metal compound (A), a char formation auxiliary agent (C), and water. Item 2 The aqueous foaming fire-resistant coating composition according to Item 1, wherein the polyvalent metal compound (A) is a metal oxide. Item 3 The aqueous foaming fire-resistant coating composition according to Item 1, wherein the polyvalent metal compound (A) is a metal organic acid salt. Item 4 The aqueous foaming fire-resistant coating composition according to any one of Items 1 to 3, wherein the usage amount of the polyvalent metal compound (A) is in the range of 0.1 to 2.0 equivalents with respect to 1 equivalent of the functional group contained in the resin (B). Item 5 The aqueous foaming fire-resistant coating composition according to any one of Items 1 to 4, wherein the functional group in the resin (B) is a carboxyl group. Item 6 The aqueous foaming fire-resistant coating composition according to any one of Items 1 to 5, wherein the acid value of the resin (B) is 3 to 100 mgKOH / g. Item 7 The aqueous foaming fire-resistant coating composition according to Item 5 or 6, wherein the resin (B) is a copolymer emulsion of a carboxyl group-containing polymerizable unsaturated monomer and other polymerizable unsaturated monomers. Item 8 The aqueous foaming fire-resistant coating composition according to Item 7, wherein the copolymerization amount of the carboxyl group-containing polymerizable unsaturated monomer is in the range of 1 to 10% by mass in all polymerizable unsaturated monomers. Item 9 The aqueous foaming refractory coating composition according to any one of items 1 to 8, further comprising a carbon source. Item 10 The aqueous foaming refractory coating composition according to any one of items 1 to 9, further comprising a foaming agent. Item 11 A two-component coating composition that is mixed and used immediately before use, wherein the first component (I) contains a polyvalent metal compound (A) and the second component (II) contains a resin (B). The aqueous foaming refractory coating composition according to any one of items 1 to 10. Item 12 A method for coating a substrate, comprising coating the surface of the substrate with the aqueous foaming refractory coating composition according to any one of items 1 to 11. Item 13 A method for protecting a structure from heat and fire, comprising coating the surface of the substrate with the aqueous foaming refractory coating composition according to any one of items 1 to 11. Regarding.

Advantages of the Invention

[0012] The aqueous foaming refractory coating composition of the present invention has good coating workability and can obtain a coating film with good appearance. This coating film forms a dense cross-linked structure during normal times, so it has excellent physical properties such as water resistance and can protect the structure from stimuli such as ultraviolet rays and rainwater. And the coating film formed by this aqueous foaming refractory coating composition expands at high temperatures such as during a fire and exhibits excellent heat insulation properties, so it can delay the collapse of the structure due to heat.

Modes for Carrying Out the Invention

[0013] In the present invention, the mass of the non-volatile components in the aqueous foaming refractory coating composition is determined by using an aqueous foaming refractory coating composition of a known mass (for example, 0.3 g) as a sample, placing this sample in a pre-weighed aluminum dish, heating this sample in an oven at 105 °C for 30 minutes, measuring the mass of the dish again, and calculating from the mass before heating and the mass of the sample after heating (see ASTM D2697).

[0014] In this specification, the non-volatile content means the residue obtained by removing the volatile components, and the residue may be solid or liquid at normal temperature.

[0015] The aqueous foamed refractory coating composition of the present invention contains a polyvalent metal compound (A) containing a metal element capable of taking a divalent or higher ionic valence, a resin (B) having a functional group capable of forming a metal bridge with the metal element contained in the polyvalent metal compound (A), a char formation auxiliary agent (C), and water.

[0016] <Polyvalent metal compound (A)> In the present invention, the polyvalent metal compound (A) is a polyvalent metal compound containing a metal element capable of taking a divalent or higher, preferably 2 to 4 valent ionic valence. Examples thereof include compounds containing metal elements such as Mg, Ca, Ba, Fe, Cu, Zn, Al, Ti, Si, Zr, and Mn. As the polyvalent metal compound, either an inorganic metal compound or an organic metal compound can be preferably used.

[0017] Examples of the inorganic metal compound include metal oxides, metal hydroxides, metal nitrates, metal sulfates, metal phosphates, etc. Among these, metal oxides are preferred.

[0018] Examples of the organic metal compound include metal organic salts, metal alkoxides, metal organic complexes, etc. Among these, metal organic salts are preferred.

[0019] Examples of the organic acid constituting the metal organic salt include formic acid, acetic acid, propionic acid, butyric acid, zinc oxalate, valeric acid, α-methylbutyric acid, salicylic acid, stearic acid, lactic acid, etc.

[0020] The amount of the polyvalent metal compound (A) used is adjusted so that the equivalent of the metal is in the range of 0.1 to 2.0 equivalents, preferably 0.15 to 1.0 equivalents, per 1 equivalent of the functional group capable of forming a metal bridge contained in the resin (B) described below, from the viewpoints of the water resistance of the cured coating film and the fire resistance of the char generated during heating.

[0021] <Resin (B)> In the present invention, as the resin (B), a resin that can be dissolved or dispersed in water is used. There is no particular limitation on the type of the resin, and when it is in the form of dispersed particles, it may be either monolayer or multilayer such as core-shell type.

[0022] As the resin (B), any conventionally known resin having a coating film-forming ability can be used without particular limitation. Specific examples thereof include acrylic resin emulsion, acrylic-silicone resin emulsion, urethane resin emulsion, fluororesin emulsion, epoxy resin emulsion, polyester resin emulsion, alkyd resin emulsion, melamine resin emulsion, etc., but are not limited thereto. Further, these may be used alone or in combination of two or more.

[0023] The resin (B) has a functional group capable of forming a metal crosslink with the metal element contained in the polyvalent metal compound (A). The metal crosslink is a crosslink structure that connects between resin molecules via a metal. The present inventors considered that such a metal crosslink is decomposed at a lower temperature than a crosslink structure by a covalent bond between non-metals, and forms a char excellent in heat insulation without preventing the expansion of the coating film when exposed to a flame. Examples of the functional group capable of forming the metal crosslink include a carboxyl group, a hydroxyl group, an acid anhydride group (-COOCO-), etc., and particularly a carboxyl group or an acid anhydride group is preferable.

[0024] In the present invention, when the resin (B) has a carboxyl group, the acid value of the resin (B) is preferably in the range of 3 to 100 mgKOH / g, particularly 5 to 80 mgKOH / g. Here, the acid value is the number of mg of potassium hydroxide required to neutralize the acid groups contained in 1 g of the mass of the resin non-volatile matter, and is determined by a conventional method based on alkali neutralization titration.

[0025] Examples of the resin (B) include a copolymer emulsion of a carboxyl group-containing polymerizable unsaturated monomer and other polymerizable unsaturated monomers.

[0026] Examples of the carboxyl group-containing polymerizable unsaturated monomer include (meth)acrylic acid, maleic acid, crotonic acid, itaconic acid, β-carboxyethyl acrylate, and combinations thereof.

[0027] When producing the copolymer emulsion, the copolymerization amount of the carboxyl group-containing polymerizable unsaturated monomer is preferably in the range of 1 to 20% by mass, particularly 3 to 10% by mass, based on all the polymerizable unsaturated monomers.

[0028] Examples of other polymerizable unsaturated monomers include alkyl or cycloalkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, tridecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, isostearyl acrylate (trade name, manufactured by Osaka Organic Chemical Industry Co., Ltd.), cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, t-butylcyclohexyl (meth)acrylate, cyclododecyl (meth)acrylate; isobornyl group-containing (meth)acrylates such as isobornyl (meth)acrylate; adamantyl group-containing (meth)acrylates such as adamantyl (meth)acrylate; vinyl aromatic compounds such as styrene, α-methylstyrene, vinyltoluene; polymerizable unsaturated monomers having an alkoxysilyl group such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, γ-(meth)acryloyloxypropyltrimethoxysilane, γ-(meth)acryloyloxypropyltriethoxysilane; Perfluoroalkyl (meth) acrylates such as perfluorobutylethyl (meth) acrylate and perfluorooctylethyl (meth) acrylate; Polymerizable unsaturated monomers having a fluorinated alkyl group such as fluoroolefin; Monomers having a photopolymerizable functional group such as a maleimide group; Nitrogen-containing polymerizable unsaturated monomers such as (meth) acrylonitrile, (meth) acrylamide, N,N-dimethylaminoethyl (meth) acrylate, N,N-dimethylaminopropyl (meth) acrylamide, and the adduct of glycidyl (meth) acrylate and amines; Monoesters of (meth) acrylic acid and a divalent alcohol having 2 to 8 carbon atoms such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate, ε-caprolactone-modified products of monoesters of (meth) acrylic acid and a divalent alcohol having 2 to 8 carbon atoms, N-hydroxymethyl (meth) acrylamide, allyl alcohol, and (meth) acrylates having a polyoxyethylene chain with a hydroxyl group at the molecular end, etc.; hydroxyl group-containing polymerizable unsaturated monomers; Epoxy group-containing polymerizable unsaturated monomers such as glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, 3,4-epoxycyclohexylethyl (meth) acrylate, 3,4-epoxycyclohexylpropyl (meth) acrylate, and allyl glycidyl ether; (Meth) acrylates having a polyoxyethylene chain with an alkoxy group at the molecular end; Sulfonic acid group-containing polymerizable unsaturated monomers such as 2-acrylamido-2-methylpropanesulfonic acid, allylsulfonic acid, sodium styrenesulfonate, sulfoethyl methacrylate, and its sodium salt or ammonium salt; Phosphoric acid group-containing polymerizable unsaturated monomers such as 2-acryloyloxyethyl acid phosphate, 2-methacryloyloxyethyl acid phosphate, 2-acryloyloxypropyl acid phosphate, 2-methacryloyloxypropyl acid phosphate; Carbonyl group-containing polymerizable unsaturated monomers such as acrolein, diacetone acrylamide, diacetone methacrylamide, acetoacetoxyethyl methacrylate, formylstyrene, vinyl alkyl ketones having 4 to 7 carbon atoms (for example, vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone); And combinations thereof. As the other polymerizable unsaturated monomers, from the viewpoints of water resistance and fire resistance, it is preferable to use alkyl or cycloalkyl (meth)acrylate and / or vinyl aromatic compounds.

[0029] The copolymer emulsion can be obtained by adopting a usual method, but from the viewpoint of the water resistance of the formed coating film, that obtained by the emulsion polymerization method is preferable. In emulsion polymerization, commonly used ionic or nonionic surfactants can be used.

[0030] Based on the total mass of the nonvolatile components in the aqueous foaming fire-resistant coating composition, the resin (B) can be present in the aqueous foaming fire-resistant coating composition in the range of 5 to 50% by mass, more preferably 10 to 35% by mass in terms of nonvolatile mass.

[0031] <Char formation auxiliary agent (C)> The char formation aid (C) is for promoting the formation of char when the coating film formed by the aqueous foaming refractory coating composition is exposed to fire. Generally, Lewis acids are considered to perform an auxiliary function in forming char, and specifically, phosphorus-containing compounds such as ammonium phosphate, ammonium polyphosphate, and phosphoric acid are used. Among phosphorus-containing compounds, ammonium phosphate compounds that are ammonium salts of phosphoric acid or polyphosphoric acid are preferred, and ammonium polyphosphate is more preferred. In the present invention, it is also possible to use other char formation aids instead of or in addition to the phosphorus-containing compounds. For example, the combination of ammonium polyphosphate and tris-(2-hydroxyethyl)isocyanurate (THEIC) is an example thereof. The above char formation aid (C) can be present in the aqueous foaming refractory coating composition in an amount of 10 to 70% by mass, more preferably 20 to 45% by mass, based on the total mass of the non-volatile components in the aqueous foaming refractory coating composition.

[0032] The aqueous foaming refractory coating composition of the present invention can further contain one or more of a carbon source, a foaming agent, a pigment, a plasticizer, and a film-forming aid.

[0033] <Carbon source> The aqueous foaming refractory coating composition can optionally contain a carbon source. Examples of the carbon source include pentaerythritol, dipentaerythritol, polyvinyl alcohol, starch, cellulose powder, and the like.

[0034] The carbon source can be present in the aqueous foaming refractory coating composition in an amount of preferably 1 to 50% by mass, more preferably 5 to 30% by mass, based on the total mass of the non-volatile components in the aqueous foaming refractory coating composition.

[0035] <Foaming agent> In the present invention, the aqueous foaming refractory coating composition can optionally contain a spumific. A spumific is one or more compounds that decompose upon exposure to heat (usually fire) to provide an expanding gas. The heat sufficient for the spumific to decompose and generate gas is usually about 90 °C or higher.

[0036] The temperature at which the spumific releases gas is desirably a temperature at which the organic polymer softens and is lower than the temperature at which char is formed. The aqueous foaming underground coating composition thus formed can form char after sufficient foaming and become a better heat insulator.

[0037] As the spumific, melamine, melamine formaldehyde, methylolated melamine, hexamethoxymethyl melamine, melamine monophosphate, melamine diphosphate, melamine polyphosphate phosphate, melamine pyrophosphate, melamine cyanurate, urea, nitrourea, dimethyl urea, dicyandiamide, guanyl urea phosphate, glycine, amine phosphate, azodicarbonamide, 4,4'-oxybis(benzenesulfonyl hydrazide), p-toluene hydrazide, p-toluenesulfonyl semicarbazide, dinitrosopentamethylenetetramine, 5-phenyltetrazole, diazoaminobenzene, etc. can be used. The above compounds decompose upon exposure to heat and release nitrogen gas. Also, ammonium borate, potassium carbonate, citric acid derivatives, etc., compounds that release carbon dioxide, water vapor and / or ammonia upon exposure to heat, and expandable graphite can also be used as the spumific.

[0038] Preferred spumifics can be melamine or its derivatives and are used alone or in combination.

[0039] When the aqueous foaming refractory coating composition of the present invention contains a spumific, its amount can preferably be present in the range of 1 to 30% by mass, more preferably 5 to 25% by mass, based on the total mass of the non-volatile components in the aqueous foaming refractory coating composition.

[0040] <Pigment> The aqueous foaming refractory coating composition of the present invention can optionally contain a pigment. The pigment excludes those which are the above-mentioned polyvalent metal compound (A). The pigment is preferably a coloring pigment, and as the coloring pigment, those known in the paint field can be used. For example, titanium dioxide (white pigment), carbon black, colored pigments such as iron oxide; filler pigments such as barite, talc, calcium carbonate, kaolin, clay, etc.; and fibers and the like can be mentioned. Based on the total mass of the non-volatile components in the aqueous foaming refractory coating composition, the pigment can preferably be present in the aqueous foaming refractory coating composition in the range of 1 to 40% by mass, more preferably 5 to 30% by mass.

[0041] <Plasticizer and / or film-forming aid> The aqueous foaming refractory coating composition of the present invention can optionally contain a plasticizer and / or a film-forming aid. The plasticizer is a compound that remains liquid at room temperature in the coating film, and those known in the paint field can be used. Specific examples of the plasticizer include, for example, fatty acid ester-based plasticizers, phosphate ester-based plasticizers, epoxy-based plasticizers, and the like.

[0042] On the one hand, the film-forming aid is a high-boiling organic solvent compatible with the resin (B), which remains in the coating film after water volatilizes and gradually volatilizes while promoting the fusion of the resin (B) particles. Specific examples of the film-forming aid include ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, ethylene glycol monohexyl ether, ethylene glycol mono-2-ethylhexyl ether, diethylene glycol monomethyl ether, diethylene glycol diethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol dibutyl ether, diethylene glycol monophenyl ether, diethylene glycol monohexyl ether, diethylene glycol monobenzyl ether, diethylene glycol mono-2-ethylhexyl ether, triethylene glycol monomethyl ether, triethylene glycol monobutyl ether, polyethylene glycol monobutyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol monophenyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monobutyl ether, and other glycol ether compounds; ester compounds such as 2,2,4-trimethylpentanediol monoisobutyrate and 2,2,4-trimethylpentanediol diisobutyrate, etc.

[0043] When the aqueous foaming refractory coating composition of the present invention contains a plasticizer and a film-forming aid, the total content in that case is preferably in the range of 0.1 to 15% by mass, more preferably 0.5 to 10% by mass, based on the non-volatile content of the coating.

[0044] <Aqueous foaming refractory coating composition> The aqueous foaming refractory coating composition of the present invention can optionally contain other components, such as pigment dispersants, catalysts, organic solvents, additives for changing the melt viscosity, rheology modifiers, curing agents, etc., but is not limited thereto.

[0045] The coating form of the aqueous foaming refractory coating composition of the present invention is not particularly limited, but it is a two-component coating composition that is mixed and used immediately before use with the first component (I) and the second component (II). The first component (I) contains a polyvalent metal compound (A), the second component (II) contains a resin (B), and it is preferable that the first component (I) and / or the second component (II) contain a char formation auxiliary agent (C) and water. In other words, the present invention includes a system for producing an aqueous foaming refractory coating composition comprising a first component (I) containing a polyvalent metal compound (A) and a second component (II) containing a resin (B).

[0046] In the case where the coating form is a multi-component system, components other than the polyvalent metal compound (A) and the resin (B) may be contained in either the first component (I) or the second component (II). In some embodiments, components other than the polyvalent metal compound (A) and the resin (B) are contained in the second component (II). In some specific embodiments, the second component (II) contains a char formation auxiliary agent (C) and water. In some specific embodiments, the second component (II) contains a char formation auxiliary agent (C), a carbon source, a foaming agent, a pigment (especially a coloring pigment), and water.

[0047] <Coating method> The present invention further relates to a method for coating a substrate, which includes coating the above aqueous foaming refractory coating composition on the surface of the substrate.

[0048] The aqueous foaming refractory coating composition of the present invention can be cured and / or dried at ambient temperature, for example, -5°C to 40°C. Therefore, it is suitable for application to large structures where heat curing is not practical.

[0049] In the present invention, the thickness of the dry film of the layer of the aqueous foaming fireproof paint composition can be appropriately selected according to the application. Typically, in the case of cellulose-based fireproof applications (applied to buildings such as office buildings), it is 100 μm to 8 mm, preferably 200 μm to 4 mm.

[0050] The present invention further relates to a method for protecting a structure from flame or heat, which includes coating the above aqueous foaming fireproof paint composition on the surface of a substrate.

[0051] The aqueous foaming fireproof paint composition of the present invention can be applied to various substrates.

[0052] Examples of the substrate include not only metals such as steel frames, aluminum, and galvanized iron sheets, but also wallpaper, plywood, wood, inorganic boards, concrete, mortar, FRP, plastics, paper, cloth, fibers, synthetic resins, rubber, silicon, electric wires and cables, etc. Examples of the structure include on-ground structures, offshore structures, etc. Particularly preferred structures include buildings defined in Articles 21 and 27 of the Building Standards Law. Some specific examples thereof include buildings, schools, hospitals, hotels, movie theaters, stores, warehouses, airports, etc.

[0053] When applying the aqueous foaming fireproof paint composition of the present invention to the steel frame of an existing structure, after performing substrate treatment such as rust removal, and if necessary, applying an undercoat paint and then applying the aqueous foaming fireproof paint of the present invention may be possible. Also, after applying the aqueous foaming fireproof paint composition of the present invention, a known topcoat may be applied.

[0054] The coating method is not particularly limited, and it can be easily applied by general methods such as brush, trowel, roller, spray, etc. It is possible not only to apply smoothly but also to form a pattern with unevenness in a thick film. These coating methods are appropriately selected according to the purpose of use of the substrate.

Examples

[0055] Hereinafter, the present invention will be further described with reference to examples. Here, "parts" and "%" mean "parts by mass" and "mass %", respectively.

[0056] Production of the main component Production Example 1 The following components were placed in a container and stirred and mixed using a planetary mixer until uniform to obtain the main component (X-1) for the aqueous foaming refractory coating composition. Melamine 8.95 parts Pentaerythritol 8.95 parts Ammonium polyphosphate 26.83 parts Titanium oxide 8.72 parts Deionized water 23.72 parts 50% acrylic resin emulsion (B-1) (Note 1) 18.03 parts 2,2,4-Trimethylpentanediol monoisobutyrate 4.27 parts Thickener 0.47 parts (Note 1) 50% acrylic resin emulsion (B-1): Styrene / 2-ethylhexyl acrylate / methacrylic acid = 81.5 / 15 / 3.5, emulsion polymer, non-volatile content 50%, acid value 23 mgKOH / g.

[0057] <Production of aqueous foaming refractory coating compositions using various polyvalent metals> Example 1 To 50 parts of the main component (X-1) obtained in Production Example 1, 2.18 parts of a 10% nickel acetate aqueous solution was added and stirred and mixed to produce an aqueous foaming refractory coating composition sample number No. 1.

[0058] Examples 2 to 17 and Comparative Examples 1 to 2 In Example 1, except that the type and blending amount of the crosslinking agent were as shown in Table 1, the aqueous foaming refractory coating composition sample numbers No. 2 to No. 19 were produced in the same manner as in Example 1.

[0059] In the table, Ni(Ac)2 means nickel acetate, Mn(Ac)2 means manganese acetate, Co(Ac)2 means cobalt acetate, and Zn(Ac)2 means zinc acetate.

[0060]

Table 1

[0061] (Note 2) 6.9% ZnO aqueous solution An aqueous zinc oxide solution was prepared with the following composition and mixed as the main ingredient. <Composition of the aqueous zinc oxide solution> Deionized water 68.3 parts Zinc oxide 6.9 parts Ammonium carbonate 12.7 parts Ammonia water 12.1 parts (Note 3) SVO2: 「Carbodilite SV02」, trade name, manufactured by Nisshinbo Co., a crosslinking agent for aqueous resins consisting of a carbodiimide solution, carbodiimide equivalent 430, active ingredient 40%.

[0062] Performance evaluation: (*) Water resistance: On a 300 mm × 100 mm × 3.2 mm blast steel plate, the back and side surfaces of the coated panel coated with each aqueous foaming refractory coating composition No. 1 to 19 to a dry film thickness of 2 mm were sealed with an epoxy / amine-based paint and forced dried at 50°C for 1 week to obtain a test panel. Then, the test panel was immersed in water at 23°C, and the time until one or more bulges with a size of 5 mm or more occurred on the coated surface of the test panel was recorded. In the table, the larger the value, the better the result. (*) Fire resistance: On a 100 mm × 100 mm × 3.2 mm blast steel plate, each aqueous foaming refractory coating composition was coated to a dry film thickness of 0.7 mm and dried at 23°C for 7 days to obtain a test panel, which was subjected to a cone calorimeter test. Specifically, a thermocouple was attached to the back side of the test panel, and it was subjected to an ignition test using a cone calorimeter with a heating intensity of 50 kw / m 2 and the temperature of the thermocouple after 20 minutes was recorded. In the table, the lower the numerical value, the better the result.

[0063] <Manufacture of aqueous foaming refractory coating compositions using acrylic resin emulsions with different acid values> Examples 18 to 21 Using the formulation compositions shown in Table 2 below, aqueous foamed refractory coating compositions Nos. 20 to 23 were produced.

[0064] [Table 2]

[0065] (Note 4) 50% acrylic resin emulsion (B-2): Styrene / 2-ethylhexyl acrylate / methacrylic acid = 80 / 15 / 5, emulsion polymer, non-volatile content 50%, acid value 33 mg KOH / g (Note 5) 50% acrylic resin emulsion (B-3): Styrene / 2-ethylhexyl acrylate / methacrylic acid = 78.5 / 15 / 6.5, emulsion polymer, non-volatile content 50%, acid value 42 mg KOH / g (Note 6) 50% acrylic resin emulsion (B-4): Styrene / 2-ethylhexyl acrylate / methacrylic acid = 77 / 15 / 8, emulsion polymer, non-volatile content 50%, acid value 52 mg KOH / g.

[0066] Performance evaluation: (*) Time to reach 500°C: Test panels were prepared in the same manner as in the above-mentioned fire resistance test and subjected to a cone calorimeter test, and the time when the temperature of the thermocouple reached 500°C was recorded. In the table, the larger the numerical value, the better the result. (*) Water resistance A water resistance test was conducted in accordance with the "immersion method" of JIS K 5600-6-1. Specifically, each steel plate was coated with each aqueous refractory coating composition to a dry film thickness of 1.5 mm and dried at 23°C for 7 days to obtain a test panel. This test panel was immersed in water at 23°C for 96 hours, and the appearance was evaluated according to the following criteria. ◎: No change at all before and after immersion, 〇: Very slight swelling is observed before and after immersion, △: Swelling is observed before and after immersion, ×: Marked swelling is observed before and after immersion.

[0067] <Examination> From the results in Tables 1 and 2, the effects of the present invention will be examined as follows.

[0068] Examples 1 to 21 are aqueous foaming refractory coating compositions within the range defined by the present invention. Comparative Example 1 is an aqueous foaming refractory coating composition outside the scope of the present invention in that it uses a crosslinking reaction between a carboxyl group and carbodiimide instead of metal crosslinking. Comparative Example 2 is an aqueous foaming refractory coating composition outside the scope of the present invention in that it does not introduce metal crosslinking and is non-crosslinked.

[0069] From the water resistance and fire resistance test results of the aqueous foaming refractory coating compositions prepared as above, the following can be said.

[0070] An aqueous foaming refractory coating composition that achieves both water resistance of the coating film formed at room temperature and fire resistance of the expanded coating film formed by heating can be obtained by combining a polyvalent metal compound capable of metal crosslinking and a functional group-containing resin. (Examples 1 to 21) When crosslinking by metal crosslinking is applied, both water resistance and fire resistance are improved as compared with the non-crosslinked case. (Comparison between Example 1 and Comparative Example 2) When crosslinking by carbodiimide is applied, the water resistance is improved but the fire resistance is decreased as compared with the non-crosslinked case. (Comparison between Comparative Example 1 and Comparative Example 2) When crosslinking by metal crosslinking is applied, the fire resistance is dramatically improved as compared with carbodiimide crosslinking. (Comparison between Examples 4, 6, 10, 13, 17 and Comparative Example 1)

Claims

1. A polyvalent metal compound (A) containing a metal element capable of taking a divalent or higher ionic valence, A resin (B) having a functional group capable of forming a metal bridge with the metal element contained in the polyvalent metal compound (A), a char formation auxiliary agent (C), a carbon source, a foaming agent, and water, An aqueous foaming refractory coating composition, wherein the polyvalent metal compound (A) contains an organic acid metal salt.

2. The aqueous foaming refractory coating composition according to Claim 1, wherein the amount of the polyvalent metal compound (A) used is in the range of 0.1 to 2.0 equivalents with respect to 1 equivalent of the functional group contained in the resin (B).

3. The aqueous foaming refractory coating composition according to Claim 1 or 2, wherein the functional group in the resin (B) is a carboxyl group.

4. The aqueous foaming refractory coating composition according to any one of Claims 1 to 3, wherein the acid value of the resin (B) is 3 to 100 mgKOH / g.

5. The aqueous foaming refractory coating composition according to Claim 3 or 4, wherein the resin (B) is a copolymer emulsion of a carboxyl group-containing polymerizable unsaturated monomer and other polymerizable unsaturated monomers.

6. The aqueous foaming refractory coating composition according to Claim 5, wherein the copolymerization amount of the carboxyl group-containing polymerizable unsaturated monomer is in the range of 1 to 10% by mass in all the polymerizable unsaturated monomers.

7. A two-component coating composition which is mixed and used immediately before use, wherein the first component (I) contains a polyvalent metal compound (A) and the second component (II) contains a resin (B), and the aqueous foaming refractory coating composition according to any one of Claims 1 to 6.

8. A method for coating a substrate, comprising coating the surface of the substrate with the aqueous foaming refractory coating composition according to any one of Claims 1 to 7.

9. A method for protecting a structure from heat and fire, comprising coating the surface of the substrate with the aqueous foaming refractory coating composition according to any one of Claims 1 to 7.

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