JP7701802B2 - Water-based foamable fireproof coating composition - Google Patents

Description

The present invention relates to an aqueous foamable fire-resistant paint composition that contains water as a diluting medium.

Because steel loses its strength rapidly at around 500°C, steel-framed structures collapse in the event of a fire, making it impossible to evacuate or put out the fire. For this reason, the Building Standards Act requires that a fire-resistant coating with insulating properties be applied to the steel frame of a structure in order to maintain its strength for a specified period of time even in the event of a fire. Examples of fire-resistant coating materials include rock wool fire-resistant coating material and foam fire-resistant paint. Rock wool fire-resistant coating material is inexpensive and widely available on the market, but it requires a thickness of 1 cm to several cm to demonstrate fire resistance, and there is an issue that it is difficult to spray.

On the other hand, foaming fireproof paint is a coating material that exhibits insulating properties by expanding the coating film as the temperature rises during a fire. Unlike rock wool, fireproof coating using foaming fireproof paint is a thin film under normal conditions and does not damage the shape of the structure itself. In the event of a fire, it expands and carbonizes, and the flame-retardant insulating layer called char suppresses the temperature rise of the steel and delays the collapse of the structure.

In Patent Document 1, the applicant proposed a foaming fireproof paint that contains a hydrolyzable silyl group-containing resin, a plasticizer, a foaming agent, and a carbonizing agent. This paint is easy to apply thickly, and produces a protective coating film that has excellent physical properties such as quick drying, internal curing, and water resistance, and can form a foamed layer with excellent fire resistance under fire conditions.

However, the foaming fireproof paint described in Patent Document 1 contains an organic solvent as a dilution medium, which causes odor problems when applied in hospitals, schools, etc. In addition, there are problems such as the inability to carry out electrical work in parallel due to the scattering of the organic solvent, and so there is an increasing demand for water-based foaming fireproof paint that uses water as a dilution medium.

For example, Patent Document 2 discloses a water-based foaming fireproof paint that contains an acrylic resin emulsion, a polyhydric alcohol, a foaming agent, a flame-retardant dehydrating agent, and an alkali-thickening emulsion. Although this paint composition has excellent workability and fire resistance, the water resistance of the coating film is insufficient, limiting its range of application.

JP 2018-159065 A JP 2015-59180 A

Fire-resistant paints are required to have physical properties such as paintability and water resistance under normal conditions, as well as fire resistance in the event of a fire. A method of cross-linking the resin that forms the coating is effective for improving the coating's physical properties such as water resistance under normal conditions, but this method often makes it difficult for the coating to expand in the event of a fire, and sufficient fire resistance is not obtained. In this way, there is a trade-off between the coating's water resistance under normal conditions and its fire resistance under fire. Furthermore, coatings formed from water-based paints are more difficult to form than those from organic solvent-based paints, so an effective method of achieving both has not been found.

The object of the present invention is to propose a water-based foaming fireproof paint composition that provides good water resistance of the coating film under normal conditions and good fire resistance of the expanding coating film that forms in the event of a fire, without restricting the scope of application of the foaming fireproof paint.

The present inventors have conducted extensive research into the above-mentioned problem. As a result, they have discovered that metal bridges formed by metal elements contained in a polyvalent metal compound and functional groups in a resin ensure water resistance under normal conditions due to a dense cross-linked structure, and that at high temperatures such as during a fire, the cross-linked structure decomposes, forming a coating film that exhibits high fire resistance without impeding expansion.

That is, the present invention relates to item 1.
A polyvalent metal compound (A) containing a metal element capable of assuming an ionic valence of 2 or more;
The aqueous foamable fireproof coating composition comprises a resin (B) having a functional group capable of forming a metal bridge with a metal element contained in the polyvalent metal compound (A), a char formation aid (C), and water.
Section 2
2. The aqueous foamable fireproof coating composition according to claim 1, wherein the polyvalent metal compound (A) is a metal oxide.
Section 3
2. The aqueous foamable fireproof coating composition according to claim 1, wherein the polyvalent metal compound (A) is an organic acid metal salt.
Section 4
Item 4. The aqueous foamable fireproof coating composition according to any one of items 1 to 3, wherein the amount of the polyvalent metal compound (A) used is within the range of 0.1 to 2.0 equivalents relative to 1 equivalent of the functional group contained in the resin (B).
Section 5
Item 5. The aqueous foamable fireproof coating composition according to any one of items 1 to 4, wherein the functional group in the resin (B) is a carboxyl group.
Section 6
Item 6. The aqueous foamable fireproof coating composition according to any one of items 1 to 5, wherein the acid value of the resin (B) is 3 to 100 mg KOH / g.
Section 7
Item 7. The aqueous foamable fireproof 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 another polymerizable unsaturated monomer.
Section 8
Item 8. The aqueous foamable fireproof coating composition according to item 7, wherein the copolymerization amount of the carboxyl group-containing polymerizable unsaturated monomer is within the range of 1 to 10 mass% of the total polymerizable unsaturated monomers.
Section 9
Item 9. The aqueous foamable fireproof coating composition according to any one of items 1 to 8, further comprising a carbon source.
Item 10
Item 10. The aqueous foamable fireproof coating composition according to any one of items 1 to 9, further comprising a foaming agent.
Item 11
Item 11. The aqueous foamable fireproof coating composition according to any one of items 1 to 10, which is a two-liquid coating composition to be used by mixing the first component (I) and the second component (II) immediately before use, wherein the first component (I) contains a polyvalent metal compound (A) and the second component (II) contains a resin (B).
Item 12
Item 12. A method for coating a substrate, comprising coating a surface of the substrate with the aqueous foamable fireproof coating composition according to any one of items 1 to 11.
Section 13
Item 12. A method for protecting a structure from heat and fire, comprising applying the aqueous foamable fire-resistant coating composition according to any one of items 1 to 11 to a surface of a substrate.
Regarding.

The aqueous foamable fire-resistant coating composition of the present invention has good coating workability and gives a coating film with good appearance.
This coating film forms a dense crosslinked structure under normal conditions, and therefore has excellent physical properties such as water resistance, and can protect structures from stimuli such as ultraviolet rays, rainwater, etc. Furthermore, the coating film formed by this aqueous foamable fireproof coating composition expands at high temperatures such as during a fire, and exhibits excellent heat insulation properties, so that it is possible to delay the collapse of the structure due to heat.

In the present invention, the mass of the non-volatile components in the aqueous foamable fireproof coating composition can be calculated by placing a known mass (e.g., 0.3 g) of the aqueous foamable fireproof coating composition as a sample in a pre-weighed aluminum dish, heating the sample in an oven at 105°C for 30 minutes, measuring the mass of the dish again, and calculating the mass of the non-volatile components from the mass of the sample before and after heating (see ASTM D2697).

In this specification, non-volatile matter means the residue remaining after removing the volatile components, and the residue may be in either a solid or liquid state at room temperature.

The aqueous foamable fireproof coating composition of the present invention contains a polyvalent metal compound (A) containing a metal element capable of assuming an ionic valence of 2 or more, 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 aid (C), and water.

<Polyvalent Metal Compound (A)>
In the present invention, the polyvalent metal compound (A) is a polyvalent metal compound containing a metal element that can have an ionic valence of divalent or more, preferably divalent to tetravalent, and examples of the polyvalent metal compound 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 suitably used.

Examples of inorganic metal compounds include metal oxides, metal hydroxides, metal nitrates, metal sulfates, and metal phosphates. Among these, metal oxides are preferred.

Examples of organometallic compounds include organic acid metal salts, metal alkoxides, and organometallic complexes. Among these, organic acid metal salts are preferred.

Examples of organic acids that make up organic acid metal salts include formic acid, acetic acid, propionic acid, butyric acid, zinc oxalate, valeric acid, α-methylbutyric acid, salicylic acid, stearic acid, and lactic acid.

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

<Resin (B)>
In the present invention, the resin (B) used is a resin that is soluble or dispersible in water. There is no particular limitation on the type of resin, and when it is in the form of dispersed particles, it may be either a single layer or a multi-layer such as a core-shell type.

As the resin (B), any conventionally known resin can be used without any particular restrictions so long as it has the ability to form a coating film. Specific examples include, but are not limited to, acrylic resin emulsion, acrylic silicone resin emulsion, urethane resin emulsion, fluororesin emulsion, epoxy resin emulsion, polyester resin emulsion, alkyd resin emulsion, and melamine resin emulsion. These may be used alone or in combination of two or more.

The resin (B) has a functional group capable of forming a metal bridge with the metal element contained in the polyvalent metal compound (A). A metal bridge is a bridge structure that connects resin molecules via a metal. The inventors believed that such metal bridges decompose at a lower temperature than bridge structures formed by covalent bonds between nonmetals, and therefore form char with excellent heat insulation properties without preventing the expansion of the coating film when exposed to flames. Examples of functional groups capable of forming the metal bridges include a carboxyl group, a hydroxyl group, and an acid anhydride group (-COOCO-), and in particular, a carboxyl group or an acid anhydride group is preferable.

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 mg KOH/g, particularly 5 to 80 mg KOH/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 nonvolatile matter, determined by a conventional method based on alkali neutralization titration.

The resin (B) may be a copolymer emulsion of a carboxyl group-containing polymerizable unsaturated monomer and other polymerizable unsaturated monomers.

Carboxyl group-containing polymerizable unsaturated monomers include (meth)acrylic acid, maleic acid, crotonic acid, itaconic acid, β-carboxyethyl acrylate, and combinations thereof.

When producing a copolymer emulsion, the amount of the carboxyl group-containing polymerizable unsaturated monomer copolymerized is preferably within the range of 1 to 20% by mass, and more preferably 3 to 10% by mass, of the total polymerizable unsaturated monomers.

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, and cyclododecyl (meth)acrylate;
(meth)acrylates having an isobornyl group, such as isobornyl (meth)acrylate;
(meth)acrylates having an adamantyl group, such as adamantyl (meth)acrylate;
Vinyl aromatic compounds such as styrene, α-methylstyrene, and vinyltoluene;
Polymerizable unsaturated monomers having an alkoxysilyl group, such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, γ-(meth)acryloyloxypropyltrimethoxysilane, and 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 fluoroolefins;
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 adducts of glycidyl (meth)acrylate and amines;
hydroxyl group-containing polymerizable unsaturated monomers such as monoesters of (meth)acrylic acid and dihydric alcohols 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 monoesters of (meth)acrylic acid and dihydric alcohols having 2 to 8 carbon atoms, N-hydroxymethyl (meth)acrylamide, allyl alcohol, and (meth)acrylates having a polyoxyethylene chain whose molecular terminal is a hydroxyl group;
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)acrylate having a polyoxyethylene chain whose molecular terminal is an alkoxy group;
Sulfonic acid group-containing polymerizable unsaturated monomers such as 2-acrylamido-2-methylpropanesulfonic acid, allylsulfonic acid, sodium styrenesulfonate, sulfoethyl methacrylate, and sodium or ammonium salts thereof;
Phosphate group-containing polymerizable unsaturated monomers such as 2-acryloyloxyethyl acid phosphate, 2-methacryloyloxyethyl acid phosphate, 2-acryloyloxypropyl acid phosphate, and 2-methacryloyloxypropyl acid phosphate;
Carbonyl group-containing polymerizable unsaturated monomers such as acrolein, diacetone acrylamide, diacetone methacrylamide, acetoacetoxyethyl methacrylate, formyl styrene, and vinyl alkyl ketones having 4 to 7 carbon atoms (e.g., vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone);
and combinations thereof.
As the other polymerizable unsaturated monomer, from the viewpoint of water resistance and fire resistance, it is preferable to use an alkyl or cycloalkyl (meth)acrylate and/or a vinyl aromatic compound.

The copolymer emulsion can be obtained by adopting a conventional method, but from the viewpoint of the water resistance of the coating film formed, it is preferable to use an emulsion polymerization method. In the emulsion polymerization, a conventionally used ionic or nonionic surfactant can be used.

The resin (B) can be present in the aqueous foamable fireproof coating composition in an amount of 5 to 50% by mass, more preferably 10 to 35% by mass, in terms of nonvolatile mass, based on the total mass of nonvolatile components in the aqueous foamable fireproof coating composition.

<Char-forming aid (C)>
The char formation aid (C) is intended to promote the formation of char when the coating film formed by the aqueous intumescent fireproof coating composition is exposed to fire. In general, Lewis acids are considered to perform the auxiliary function of forming char, and specifically, phosphorus-containing compounds such as ammonium phosphate, ammonium polyphosphate, and phosphoric acid are used. Among the phosphorus-containing compounds, ammonium phosphate compounds, which 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, a combination of ammonium polyphosphate and tris-(2-hydroxyethyl)isocyanurate (THEIC) is one example.
The char-forming auxiliary (C) may be present in the aqueous foamable fire-resistant coating composition in an amount of 10 to 70% by weight, more preferably 20 to 45% by weight, based on the total weight of the non-volatile components in the aqueous foamable fire-resistant coating composition.

The aqueous foamable fireproof coating composition of the present invention may further contain one or more of the following: a carbon source, a foaming agent, a pigment, a plasticizer, and a film-forming aid.

<Carbon source>
The aqueous intumescent fire-resistant coating composition may optionally contain a carbon source, such as pentaerythritol, dipentaerythritol, polyvinyl alcohol, starch, cellulose powder, and the like.

The carbon source may be present in the aqueous foamable fire-resistant 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 foamable fire-resistant coating composition.

<Foaming Agent>
The water-based intumescent fire-resistant coating composition of the present invention can optionally contain a spumific. A spumific is one or more compounds that decompose to provide an expanding gas when exposed to heat (usually fire). The heat required for the spumific to decompose and generate gas is usually about 90° C. or higher.

The temperature at which the blowing agent releases gas is preferably a temperature at which the organic polymer becomes soft, but lower than the temperature at which char is formed. The aqueous foaming underground coating composition thus formed will foam sufficiently and then form char, making it a better insulator.

As the blowing agent, melamine, melamine formaldehyde, methylol melamine, hexamethoxymethyl melamine, melamine monophosphate, melamine diphosphate, melamine polyphosphate phosphate, melamine pyrophosphate, melamine cyanurate, urea, nitrourea, dimethylurea, dicyandiamide, guanylurea phosphate, glycine, amine phosphate, azodicarbonamide, 4,4'-oxybis(benzenesulfonylhydrazide), p-toluenehydrazide, p-toluenesulfonylsemicarbazide, dinitrosopentamethylenetetramine, 5-phenyltetrazole, diazoaminobenzene, etc. can be used. The above compounds decompose when exposed to heat and release nitrogen gas. In addition, compounds that release carbon dioxide, water vapor and/or ammonia when exposed to heat, such as ammonium borate, potassium carbonate, and citric acid derivatives, and expandable graphite can also be used as the blowing agent.

The preferred blowing agent can be melamine or its derivatives, used alone or in combination.

When the aqueous foamable fireproof coating composition of the present invention contains a foaming agent, the amount of the foaming agent is preferably in the range of 1 to 30 mass %, more preferably 5 to 25 mass %, based on the total mass of the non-volatile components in the aqueous foamable fireproof coating composition.

<Pigments>
The aqueous foamable fireproof coating composition of the present invention may optionally contain a pigment. The pigment is not limited to the polyvalent metal compound (A). The pigment is preferably a colored pigment, and any color pigment known in the coating field may be used, including, for example, colored pigments such as titanium dioxide (white pigment), carbon black, and iron oxide; filler pigments such as baryte, talc, calcium carbonate, kaolin, and clay; and fibers.
The pigment may be present in the aqueous foamable fire-resistant coating composition in an amount of preferably 1 to 40% by mass, more preferably 5 to 30% by mass, based on the total mass of the non-volatile components in the aqueous foamable fire-resistant coating composition.

<Plasticizer and/or Film-Forming Aid>
The aqueous foamable fire-resistant coating composition of the present invention may optionally contain a plasticizer and/or a coalescent.
The plasticizer is a compound that remains in the coating film and is liquid at room temperature, and any compound known in the coating field can be used. Specific examples of the plasticizer include fatty acid ester plasticizers, phosphate ester plasticizers, and epoxy plasticizers.

On the other hand, the film-forming aid is a high-boiling organic solvent that is compatible with resin (B), and is a component that remains in the coating film even after the water has evaporated and gradually evaporates while promoting the fusion of resin (B) particles. Specific examples of film-forming aids 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, and diethylene glycol mono 2-ethylhexyl ether. , glycol ether compounds such as 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, and tripropylene glycol monobutyl ether; and ester compounds such as 2,2,4-trimethylpentanediol monoisobutyrate and 2,2,4-trimethylpentanediol diisobutyrate.

When the aqueous foamable fireproof coating composition of the present invention contains a plasticizer and a film-forming aid, the total content is preferably within the range of 0.1 to 15 mass %, more preferably 0.5 to 10 mass %, based on the non-volatile content of the coating.

<Water-based foamable fireproof coating composition>
The water-based foamable fire-resistant coating composition of the present invention can optionally contain other components, such as, but not limited to, pigment dispersants, catalysts, organic solvents, additives for modifying melt viscosity, rheology modifiers, and curing agents.

The form of the aqueous foamable fireproof coating composition of the present invention is not particularly limited, but it is preferable that the composition is a two-liquid coating composition in which the first component (I) and the second component (II) are mixed immediately before use, the first component (I) contains a polyvalent metal compound (A), the second component (II) contains a resin (B), and the first component (I) and/or the second component (II) contain a char formation aid (C) and water. In other words, the present invention encompasses a system for producing an aqueous foamable fireproof coating composition comprising the first component (I) containing the polyvalent metal compound (A) and the second component (II) containing the resin (B).

When the paint is in the form of a multi-component system, the 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, the 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) includes the char-forming adjuvant (C) and water. In some specific embodiments, the second component (II) includes the char-forming adjuvant (C), a carbon source, a foaming agent, a pigment (particularly a color pigment), and water.

<Painting method>
The present invention further relates to a method for coating a substrate, which comprises coating a surface of the substrate with the above-mentioned aqueous foamable fire-resistant coating composition.

The aqueous foamable fire-resistant coating composition of the present invention can be cured and/or dried at ambient temperatures, for example, from -5°C to 40°C. It is therefore suitable for application to large structures where heat curing is not practical.

In the present invention, the dry film thickness of the layer of the aqueous foamable fireproof coating composition can be appropriately selected depending on the application. Typically, for cellulose-based fireproofing applications (e.g., application to buildings such as office buildings), the thickness is 100 μm to 8 mm, preferably 200 μm to 4 mm.

The present invention further relates to a method for protecting a structure from flame or heat, which comprises applying the above-mentioned aqueous foamable fire-resistant coating composition to a substrate surface.

The aqueous foamable fire-resistant coating composition of the present invention can be applied to a variety of substrates.

Examples of substrates include metals such as steel frames, aluminum, and galvanized steel sheets, as well as wallpaper, plywood, wood, inorganic boards, concrete, mortar, FRP, plastics, paper, cloth, fibers, synthetic resins, rubber, silicon, and electric cables. Examples of structures include terrestrial structures and marine structures, and particularly suitable structures include buildings as defined in Articles 21 and 27 of the Building Standards Act. Specific examples include buildings, schools, hospitals, hotels, movie theaters, stores, warehouses, airports, etc.

When applying the aqueous foaming fireproof paint composition of the present invention to the steel frame of an existing structure, the aqueous foaming fireproof paint of the present invention may be applied after surface preparation such as rust removal and, if necessary, after applying an undercoat paint. In addition, after applying the aqueous foaming fireproof paint composition of the present invention, a known topcoat paint may be applied.

There are no particular limitations on the application method, and the coating can be easily applied using common methods such as brushing, troweling, rollers, and spraying. It is possible to apply the coating smoothly, as well as to form a thick film with an uneven pattern. These application methods are appropriately selected depending on the intended use of the substrate.

The present invention will be further described below with reference to examples. Here, "parts" and "%" mean "parts by mass" and "% by mass", respectively.

Production of main component Production Example 1
The following components were placed in a container and mixed with a planetary mixer until uniform, to obtain a main component (X-1) for a water-based foamable fire-resistant 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 mg KOH / g.

<Production of Water-Based Foamable Fireproof Coating Composition Using Various Polyvalent Metals>
Example 1
2.18 parts of a 10% aqueous nickel acetate solution was added to 50 parts of the main component (X-1) obtained in Production Example 1 and mixed with stirring to produce an aqueous foamable fireproof coating composition sample number 1.

Examples 2 to 17 and Comparative Examples 1 to 2
Each of the aqueous foamable fireproof coating composition samples No. 2 to No. 19 was produced in the same manner as in Example 1, except that the type and amount of the crosslinking agent were as shown in Table 1.

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.

(Note 2) 6.9% ZnO aqueous solution A zinc oxide aqueous solution was prepared according to the following composition and mixed with the base agent.
<Composition of zinc oxide aqueous 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" product name, manufactured by Nisshinbo, a crosslinking agent for aqueous resins consisting of a carbodiimide solution, carbodiimide equivalent 430, active ingredient 40%.

Performance evaluation:
(*)water resistance:
Each of the aqueous foaming fireproof coating compositions No. 1 to 19 was applied to a blasted steel plate measuring 300 mm x 100 mm x 3.2 mm so that the dry film thickness was 2 mm. The back and sides of the coated panel were sealed with an epoxy/amine-based paint and forced dried at 50°C for one week to prepare a test panel. The test panel was then immersed in water at 23°C, and the time until one or more blisters measuring 5 mm or more appeared on the coated surface of the test panel was recorded. In the table, the higher the value, the better the result.
(*) Fire resistance:
Each aqueous foaming fireproof coating composition was applied to a blast steel plate of 100 mm x 100 mm x 3.2 mm so that the dry film thickness was 0.7 mm, and the plate was dried at 23 ° C for 7 days to prepare 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 the panel was subjected to an ignition test using a cone calorimeter with a heating intensity of 50 kW / ^m2 , and the temperature of the thermocouple after 20 minutes was recorded. In the table, the lower the value, the better the result.

<Production of Water-Based Foamable Fireproof Coating Composition Using Acrylic Resin Emulsions with Different Acid Values>
Examples 18 to 21
According to the blending compositions shown in Table 2 below, water-based foamable fireproof coating compositions No. 20 to 23 were produced.

(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.

Performance evaluation:
(*) Time to reach 500 degrees:
A test panel was prepared in the same manner as in the fire resistance test, and subjected to a cone calorimeter test, and the time it took for the temperature of the thermocouple to reach 500° C. was recorded. In the table, the higher the value, the better the result.
(*) Water resistance: Water resistance test was carried out in accordance with the "immersion method" of JIS K 5600-6-1.
Specifically, each water-based fireproof coating composition was applied to each steel plate to a dry film thickness of 1.5 mm and dried for 7 days at 23° C. to prepare a test panel. The 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
○: Very slight swelling was observed before and after immersion.
△: Blisters were observed before and after immersion.
×: Blisters were significantly observed before and after immersion.

<Consideration>
Based on the results of Tables 1 and 2, the effects of the present invention will be considered below.

Examples 1 to 21 are water-based intumescent fire-resistant coating compositions within the range defined by the present invention.
Comparative Example 1 is an aqueous foamable fireproof coating composition that is outside the scope of the present invention in that it utilizes a crosslinking reaction between a carboxyl group and a carbodiimide instead of metal crosslinking.
Comparative Example 2 is an aqueous foamable fire-resistant coating composition that does not incorporate metal bridges and is non-crosslinked, and thus falls outside the scope of the present invention.

The following can be said based on the results of water resistance and fire resistance tests using the water-based foaming fire-resistant paint composition prepared as described above.

By combining a polyvalent metal compound capable of metal cross-linking with a functional group-containing resin, a water-based foamable fireproof coating composition can be obtained that achieves both the water resistance of the coating film formed at room temperature and the fire resistance of the expandable coating film formed by heating. (Examples 1 to 21)
When cross-linking by metal bridges is applied, both water resistance and fire resistance are improved compared to the case where cross-linking is not performed (Comparison between Example 1 and Comparative Example 2).
When crosslinking with carbodiimide is applied, water resistance is improved but fire resistance is decreased compared to the case where crosslinking is not performed (Comparison between Comparative Example 1 and Comparative Example 2).
When crosslinking by metal crosslinking is applied, the fire resistance is dramatically improved compared to carbodiimide crosslinking. (Comparison of Examples 4, 6, 10, 13, and 17 with Comparative Example 1)

Claims (9)

A polyvalent metal compound (A) containing a metal element capable of assuming an ionic valence of 2 or more;
The composition comprises a resin (B) having a functional group capable of forming a metal bridge with a metal element contained in the polyvalent metal compound (A), a char formation aid (C) , a carbon source, a blowing agent and water ,
The aqueous foamable fire-resistant coating composition , wherein the polyvalent metal compound (A) comprises an organic acid metal salt . The aqueous foamable fireproof coating composition according to claim 1 , wherein the amount of the polyvalent metal compound (A) used is within the range of 0.1 to 2.0 equivalents per equivalent of the functional group contained in the resin (B). 3. The aqueous foamable fireproof coating composition according to claim 1 , wherein the functional group in the resin (B) is a carboxyl group. The aqueous foamable fireproof 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 foamable fireproof coating composition according to claim 3 , wherein the resin (B) is a copolymer emulsion of a carboxyl group-containing polymerizable unsaturated monomer and another polymerizable unsaturated monomer. 6. The aqueous foamable fireproof coating composition according to claim 5 , wherein the copolymerization amount of the carboxyl group-containing polymerizable unsaturated monomer is within the range of 1 to 10 mass % of the total polymerizable unsaturated monomers. The aqueous foamable fireproof coating composition according to any one of claims 1 to 6, which is a two-liquid type coating composition to be used by mixing the first component (I) and the second component (II) immediately before use, wherein the first component (I) contains a polyvalent metal compound (A) and the second component (II) contains a resin (B). A method for coating a substrate, comprising coating a surface of the substrate with the aqueous foamable fireproof coating composition according to any one of claims 1 to 7 . A method for protecting a structure from heat and fire, comprising applying to a surface of a substrate the aqueous foamable fire-resistant coating composition according to any one of claims 1 to 7 .