JP5049098B2 - Foam fireproof paint - Google Patents

Description

  The present invention relates to a novel foamable refractory paint.

  As a material for protecting a base material such as steel, concrete, wood, and synthetic resin from a fire, a foamable fireproof paint that forms a foamed layer by a temperature rise at the time of fire is known.

  Foamable fire-resistant paints contain a component that decomposes as the temperature rises to generate a nonflammable gas and a component that carbonizes to form a porous carbonized layer. The fire extinguishing effect is exhibited by the occurrence of fire, and the heat insulating effect is exhibited by the formation of a porous carbonized layer by the carbonized component. Advantages of the foamable fire-resistant paint include that it can be made thinner than conventional fire-resistant coating materials, and can be finished in a refreshing feeling with less pressure.

  Various proposals have been made with respect to such foamable fire-resistant paints for the purpose of improving various physical properties such as fire resistance. For example, JP-A-10-7947 (Patent Document 1) describes using a bromine-containing phosphate ester having a melting point of 150 ° C. or higher and a bromine content of 50% by weight or more as a flame retardant. Japanese Patent Application Laid-Open No. 10-17796 (Patent Document 2) describes that in addition to polyhydric alcohol, nitrogen-containing foaming agent, flame retardant dehydrating agent, and synthetic resin, expansive graphite is further blended. Japanese Unexamined Patent Publication No. 2000-169853 (Patent Document 3) describes that at least one selected from an azo compound, a hydrazo compound, a nitroso compound, and a sulfonyl hydrazide compound is combined with expanded graphite and the like. Japanese Patent Laid-Open No. 2001-115093 (Patent Document 4) describes blending titanium oxide having anatase crystal form as titanium oxide. Japanese Patent Application Laid-Open No. 2001-323216 (Patent Document 5) describes that the average particle size of inorganic fillers, phosphorus-based flame retardants, and the like is adjusted to 10 to 50 μm.

Japanese Patent Laid-Open No. 10-7947 JP-A-10-17796 JP 2000-169853 A Japanese Patent Laid-Open No. 2001-115093 JP 2001-323216 A

By the way, in recent years, in the paint field, the water-based process has been promoted against the background of a reduction in environmental load, and a water-type paint is also demanded for such a foam fire-resistant paint. Even in the above-mentioned patent documents, there is one which describes that a resin such as a synthetic resin emulsion can be used as a binder.
However, with foamable fireproof paints using synthetic resin emulsions, it is difficult to obtain practically satisfactory performance in terms of foaming magnification, strength, etc. of the foamed carbonized layer even if various ingenuity is applied to its formulation. .

  The present invention has been made in view of such problems, and provides a water-based foaming fireproof paint that can form a foamed carbonized layer having sufficient foaming ratio, strength, and the like, and has excellent fireproof performance. It is intended.

As a result of intensive studies to achieve the above object, the present inventor, as for the fire resistance performance of the foamable fire resistant paint using the synthetic resin emulsion as a binder, the influence of the functional group of the resin component constituting the synthetic resin emulsion As a result, the present invention has been completed.
That is, the present invention relates to the following foamable fireproof paint.

1. In the foamable refractory paint containing a synthetic resin emulsion, a phosphorus compound, a polyhydric alcohol and a filler, the synthetic resin emulsion has a hydroxyl group as a functional group, and the hydroxyl value in the resin solid content is 0.1 to 100 mgKOH / g. A foaming fireproof paint characterized by being.
2. The synthetic resin emulsion is an emulsion polymer of a monomer group mainly composed of (meth) acrylic acid alkyl ester and / or an aromatic monomer, and the ratio of the hydroxyl group-containing monomer in the monomer group is 0.5 to 15% by weight. It is what is included in 1. The foamable fireproof paint described.
3. The synthetic resin emulsion contains 50% by weight or more of a hydrophobic monomer having a water solubility of 1 g / 100 ml or less in the monomer group. Or 2. The foamable fireproof paint described.

  According to the foamable fire-resistant paint of the present invention, a dense foamed carbonized layer having excellent foamability can be formed at the time of a fire, and the temperature rise of a substrate such as a steel material can be effectively suppressed.

Hereinafter, the present invention will be described in detail based on the embodiments.
The foamable fire-resistant paint of the present invention includes a synthetic resin emulsion, a phosphorus compound, a polyhydric alcohol, and a filler. Among these, as the synthetic resin emulsion, a synthetic resin emulsion having a hydroxyl group as a functional group and having a hydroxyl value of 0.1 to 100 mgKOH / g in the resin solid content is used. In the present invention, by using such a synthetic resin emulsion having a hydroxyl group, it is possible to form a foamed carbonized layer having excellent foaming properties and having high density in the foamed state. As the hydroxyl group, those bonded to a carbon atom are preferred.

  The hydroxyl value in the resin solid content of the synthetic resin emulsion is 0.1 to 100 mgKOH / g, preferably 1 to 80 mgKOH / g, more preferably 2 to 60 mgKOH / g. When the hydroxyl value of the synthetic resin emulsion is too small, the density of the foamed carbonized layer cannot be increased, and the strength of the foamed carbonized layer becomes insufficient. On the contrary, when the hydroxyl value is too large, the expansion ratio of the foamed carbonized layer is lowered, and it is difficult to obtain sufficient performance in heat insulation. The hydroxyl value in the present invention is a value represented by the number of mg of potassium hydroxide equimolar to the hydroxyl group contained in 1 g of resin solid content.

  As the synthetic resin emulsion in the present invention, those satisfying the above conditions can be used. Specifically, the synthetic resin emulsion is an emulsion polymer of a monomer group mainly composed of (meth) acrylic acid alkyl ester and / or aromatic monomer. The monomer group preferably contains a hydroxyl group-containing monomer at a ratio of 0.5 to 15% by weight. If such a synthetic resin emulsion is used, the effect of this invention can be acquired stably. Moreover, various physical properties such as water resistance and durability of the coating film can be enhanced. In the present invention, the acrylic acid alkyl ester and the methacrylic acid alkyl ester are collectively referred to as (meth) acrylic acid alkyl ester.

Specific examples of the (meth) acrylic acid alkyl ester include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, n-amyl ( (Meth) acrylate, isoamyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, octadecyl (meth) acrylate, Examples include cyclohexyl (meth) acrylate, phenyl (meth) acrylate, and benzyl (meth) acrylate. The weight ratio of the (meth) acrylic acid alkyl ester in the monomer group is usually 30% by weight or more, preferably 40% by weight or more, and more preferably 50% by weight or more. Although an upper limit is not specifically limited, Usually, it is about 99.5 weight% or less (preferably 99 weight% or less) grade.
Specific examples of the aromatic monomer include styrene, 2-methylstyrene, vinyltoluene, t-butylstyrene, chlorostyrene, vinylanisole, vinylnaphthalene, divinylbenzene, and the like. The weight ratio of the aromatic monomer in the monomer group is usually 5 to 70% by weight, preferably 10 to 50% by weight.
In the synthetic resin emulsion in the present invention, one containing either (meth) acrylic acid alkyl ester, aromatic monomer or both in the monomer composition can be used. In particular, if both (meth) acrylic acid alkyl ester and aromatic monomer are used, advantageous effects in water resistance, fire resistance and the like are obtained.

In the synthetic resin emulsion in the present invention, it is desirable to impart a hydroxyl group with a hydroxyl group-containing monomer. In the present invention, by using a synthetic resin emulsion in which such a hydroxyl group-containing monomer is copolymerized, it is possible to form a foamed carbonized layer that is excellent in foamability and dense in the foamed state. . Specifically, examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, 4-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and the like.
The ratio of the hydroxyl group-containing monomer in the monomer group is usually 0.5 to 15% by weight, preferably 1 to 10% by weight. When the hydroxyl group-containing monomer is less than 0.5% by weight, it is difficult to increase the density of the foamed carbonized layer, and the strength of the foamed carbonized layer tends to be insufficient. When the amount of the hydroxyl group-containing monomer is more than 15% by weight, the expansion ratio becomes insufficient, which may adversely affect water resistance and the like.

The synthetic resin emulsion in the present invention preferably contains a nonionic monomer selected from a carbonyl group-containing monomer and a nitrile group-containing monomer as the monomer component. By using such a monomer, coating stability such as storage stability and mechanical stirring stability can be enhanced while maintaining foaming performance at high temperatures.
Specifically, examples of the carbonyl group-containing monomer include acrolein, diacetone (meth) acrylamide, vinyl methyl ketone, vinyl ethyl ketone, and vinyl butyl ketone. Examples of the nitrile group-containing monomer include acrylonitrile and methacrylonitrile.
The ratio (total weight ratio) of the nonionic monomers in the monomer group is usually 0.5 to 15% by weight, preferably 1 to 10% by weight. If it is in such a range, the effect excellent in the point of paint stability can be acquired.

  In the synthetic resin emulsion in the present invention, a polymerizable monomer other than the above may be used as a constituent component if necessary. Examples of such polymerizable monomers include carboxyl group-containing monomers such as acrylic acid, methacrylic acid, crotonic acid, maleic acid or a monoalkyl ester thereof, itaconic acid or a monoalkyl ester thereof, fumaric acid or a monoalkyl ester thereof; Phosphoric group-containing monomers such as monoethyl phosphate of hydroxyethyl (meth) acrylate, monophosphate ester of hydroxypropyl (meth) acrylate, monophosphate ester of hydroxybutyl (meth) acrylate; allyl sulfonic acid, styrene sulfonic acid, vinyl sulfone Acid, 2-methylpropanesulfonic acid and other sulfonic acid group-containing monomers; N-methylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminoethyl vinyl ether Amino group-containing monomers such as vinyl ester monomers such as vinyl acetate and vinyl propionate; Amide group-containing monomers such as acrylamide, methacrylamide, maleic acid amide, N-methylol (meth) acrylamide; Glycidyl (meth) acrylate, diglycidyl Epoxy group-containing monomers such as (meth) acrylate and allyl glycidyl ether; alkoxysilyl group-containing monomers such as vinyltrimethoxysilane, vinyltriethoxysilane, and γ- (meth) acryloyloxypropyltrimethoxysilane; vinylidene chloride and vinylidene fluoride Other vinylidene halide monomers such as ethylene, propylene, isoprene, butadiene, vinyl pyrrolidone, vinyl chloride, vinyl ether, vinyl ketone, vinyl amide, chloropropyl Emissions, and the like. Among these, an ionic monomer selected from a carboxyl group-containing monomer, a phosphate group-containing monomer, and a sulfonic acid group-containing monomer is 2% by weight or less (preferably 1% by weight or less, more preferably 0.8% by weight) in the monomer group. Hereinafter, it is desirable to use within the range of 0.5 wt% or less. An embodiment that does not contain such an ionic monomer in the monomer group is also suitable.

  The synthetic resin emulsion in the present invention is an emulsion polymer of a monomer group mainly composed of a hydrophobic monomer having a solubility in water of 1 g / 100 ml or less. In the monomer group, 0.5 to 15 wt. What is contained in the ratio of% is suitable. In general, a foamable fire-resistant paint using a synthetic resin emulsion as a binder does not provide sufficient water resistance, and the original foaming performance may not be exhibited due to the influence of rainfall, condensation, and the like. On the other hand, if a synthetic resin emulsion composed of such constituents is used, a coating film having excellent water resistance can be formed, and the foaming performance is prevented from being lowered due to the influence of rainfall, condensation, etc., and stable foaming is achieved. It becomes possible to demonstrate performance. The water solubility mentioned here indicates the weight of the monomer dissolved in 100 ml of water at a temperature of 20 ° C.

  Examples of such a hydrophobic monomer include n-butyl (meth) acrylate, isobutyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, decyl (meth) ) Acrylate, dodecyl (meth) acrylate, octadecyl (meth) acrylate, cyclohexyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, styrene and the like. Such a hydrophobic monomer has a water solubility of 1 g / 100 ml or less, preferably 0.9 g / 100 ml or less, more preferably 0.8 g / 100 ml or less.

  The weight ratio of the hydrophobic monomer in the monomer group is preferably 50% by weight or more, and more preferably 55% by weight or more. Although an upper limit is not specifically limited, Usually, it is about 99.5 weight% or less (preferably 99 weight% or less) grade.

The synthetic resin emulsion in the present invention can be produced by emulsion polymerization of a monomer group in which the polymerizable monomers are appropriately mixed. As the polymerization method, a known method may be employed, and soap-free emulsion polymerization, feed emulsion polymerization, seed emulsion polymerization, etc. may be employed in addition to ordinary emulsion polymerization. During the polymerization, an emulsifier, an initiator, a dispersant, a polymerization inhibitor, a polymerization inhibitor, a buffer, a chain transfer agent, and the like can be used.
As an emulsifier when performing emulsion polymerization, an anionic emulsifier, a cationic emulsifier, a nonionic emulsifier, an amphoteric emulsifier, and the like can be used. These may be reactive types (reactive emulsifiers) having polymerizable unsaturated groups. As the emulsifier, one or more of these emulsifiers can be used as appropriate. Usually, an anionic emulsifier and a nonionic emulsifier may be used alone or in combination. Specific examples of the emulsifier include alkyl benzene sulfonates such as sodium dodecylbenzene sulfonate and sodium dodecyl sulfate, fatty acid salts, rosinates, alkyl sulfates, alkyl sulfosuccinates, α-olefin sulfonates, and alkyl naphthalenes. Anionic emulsifiers such as sulfonates and polyoxyethylene alkyl (aryl) sulfates; quaternary ammonium salts such as lauryl trialkyl ammonium salts, stearyl trialkyl ammonium salts, trialkyl benzyl ammonium salts, primary to primary Cationic emulsifiers such as tertiary amine salt, lauryl pyridinium salt, benzalkonium salt, benzethonium salt or lauryl amine acetate; polyoxyethylene alkyl ether, polyoxyethylene alkyl Nonionic emulsifiers such as phenol ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan alkyl ester; amphoteric surfactants such as carboxybetaine type, sulfobetaine type, aminocarboxylic acid type, imidazoline derivative type; Eleminol JS-2 (Sanyo) Kasei Kogyo), Eleminol RS-30 (Sanyo Kasei Kogyo), Latemuru S-180A (Kao), Aqualon HS-05 (Daiichi Kogyo Seiyaku), Light Ester 041MA (Kyoeisha Chemical), Aqualon KH-10 Examples include reactive emulsifiers such as (Daiichi Kogyo Seiyaku Co., Ltd.) and Adeka Soap SE-10N (Asahi Denka).

The glass transition temperature of the synthetic resin emulsion can be adjusted by selecting the kind of the polymerizable monomer, the mixing ratio, and the like. The glass transition temperature may be appropriately set in consideration of final required performance and the like, but is usually about −50 to 80 ° C., preferably about −40 to 60 ° C. In the present invention, two or more kinds of synthetic resin emulsions having different glass transition temperatures can also be used. In addition, the glass transition temperature of a synthetic resin emulsion can be calculated | required with the formula of Fox.
The average particle size of the synthetic resin emulsion is usually 50 to 500 nm, preferably 100 to 300 nm. This average particle diameter can be measured by a dynamic light scattering method.

  In the foamable fireproof paint of the present invention, such a synthetic resin emulsion is used as a binder, but other binders can be used in combination as long as the effects of the present invention are not impaired. When a plurality of binders are used, the ratio of the synthetic resin emulsion may be 50% by weight or more (preferably 70% by weight or more, more preferably 90% by weight or more) in the solid content of the binder.

  The phosphorus compound in the foamable fire-resistant paint of the present invention exhibits at least one effect such as dehydration cooling effect, non-combustible gas generation effect, binder carbonization promoting effect, etc. in the event of a fire, and exhibits an effect of suppressing resin combustion. It is a component that can. Examples of such phosphorus compounds include tricresyl phosphate, diphenyl cresyl phosphate, diphenyl octyl phosphate, tri (β-chloroethyl) phosphate, tributyl phosphate, tri (dichloropropyl) phosphate, triphenyl phosphate. , Tri (dibromopropyl) phosphate, chlorophosphonate, bromophosphonate, diethyl-N, N-bis (2-hydroxyethyl) aminomethylphosphate, di (polyoxyethylene) hydroxymethylphosphate, three Examples thereof include phosphorus compounds such as phosphorus chloride, phosphorus pentachloride, ammonium phosphate, and ammonium polyphosphate. Of these, ammonium polyphosphate is particularly preferred in the present invention. These phosphorus compounds may be subjected to surface treatment or surface coating. The mixing ratio of the phosphorus compound is usually 50 to 2000 parts by weight (preferably 100 to 1000 parts by weight) with respect to 100 parts by weight of the solid content of the synthetic resin emulsion.

  The polyhydric alcohol has a function of forming a thick foamed carbonized layer having excellent heat insulation properties by dehydrating and carbonizing itself together with carbonization of the binder due to fire. Examples of the polyhydric alcohol include pentaerythritol, dipentaerythritol, tripentaerythritol, neopentaerythritol, trimethylolpropane, sorbitol, inositol, mannitol, glucose fructose, starch, and cellulose. The mixing ratio of the polyhydric alcohol is usually 5 to 600 parts by weight (preferably 10 to 400 parts by weight) with respect to 100 parts by weight of the solid content of the synthetic resin emulsion.

In addition to the above-mentioned components, a filler is blended in the foamable fireproof paint of the present invention. Examples of fillers include silicates such as talc; carbonates such as calcium carbonate and sodium carbonate; metal oxides such as aluminum oxide, titanium dioxide, and zinc oxide; natural minerals such as clay, clay, shirasu, mica, and silica. Kinds: hollow bodies such as glass balloons and hollow resin beads (resin balloons). The average particle size of the filler is usually 0.1 to 150 μm , preferably 0.2 to 100 μm . In the present invention, it is possible to adjust the physical properties of the coating film and the coating surface state during film formation or after film formation by appropriately combining different types of fillers or using appropriate combinations of fillers having different average particle sizes. You can also. The mixing ratio of the filler is usually 5 to 600 parts by weight (preferably 10 to 400 parts by weight, more preferably 20 to 300 parts by weight) with respect to 100 parts by weight of the solid content of the synthetic resin emulsion.

  In the foamable fireproof paint according to the present invention, it is preferable to use a cross-linking agent capable of reacting with the reactive functional group contained in the synthetic resin emulsion. In the present invention, by using such a component, the water resistance, durability, and drying property of the laminated coating film are enhanced, and the occurrence of swelling and peeling of the coating film due to rain, condensation, etc. and the reduction in fire resistance are suppressed. Is possible.

What is necessary is just to select a crosslinking agent by the combination with the reactive functional group contained in a synthetic resin emulsion. Examples of combinations of these functional groups include, for example, epoxy group-amino group, hydroxyl group-isocyanate group, carboxyl group-epoxy group, carboxyl group-carbodiimide group, carboxyl group-oxazoline group, carbonyl group-hydrazide group, hydrolyzable silyl group. And the like.
Among these, a preferable combination in the present invention includes a combination in which the synthetic resin emulsion to be used is a carbonyl group-containing synthetic resin emulsion and the crosslinking agent is a compound capable of reacting with a carbonyl group.

  Examples of the compound capable of reacting with a carbonyl group include hydrazide group-containing compounds. Specifically, examples of the hydrazide group-containing compound include malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, maleic acid dihydrazide, and the like.

  The mixing ratio of the crosslinking agent is usually 0.1 to 10 parts by weight (preferably 1 to 5 parts by weight) with respect to 100 parts by weight (solid content) of the synthetic resin emulsion. If it is in such a range, sufficient physical property improvement effects in water resistance, durability and the like can be obtained. When there are too few crosslinking agents, it is difficult to obtain such an effect of improving physical properties. When there are too many crosslinking agents, there exists a possibility of having a bad influence on stability, foamability, etc. of a foamable fireproof paint.

  Moreover, a foaming agent can also be mix | blended with the foamable fireproof paint of this invention as needed. Examples of the foaming agent include melamine and derivatives thereof, dicyandiamide and derivatives thereof, azobistetrazole and derivatives thereof, azodicarbonamide, urea, thiourea, and ethylene urea. In addition, the hydrazide-containing compound that is the above-mentioned crosslinking agent may act as a foaming agent. The mixing ratio of the foaming agent is usually 5 to 600 parts by weight (preferably 10 to 400 parts by weight) with respect to 100 parts by weight of the solid content of the synthetic resin emulsion.

The foamable fire-resistant paint of the present invention can be blended with various additives that can be used in ordinary paints as components other than those described above. Examples of such components include pigments, fibers, thickeners, film-forming aids, leveling agents, wetting agents, plasticizers, antifreezing agents, pH adjusters, antiseptics, antifungal agents, antialgae agents, and antibacterial agents. Agents, dispersants, antifoaming agents, adsorbents, crosslinking agents, ultraviolet absorbers, antioxidants, catalysts and the like. Moreover, expansive substances, such as expansive graphite and unexpanded vermiculite, can also be mix | blended.
The composition of the present invention can be produced by uniformly mixing the above components by a conventional method. Usually, a one-pack type may be used.
What is necessary is just to set the viscosity of this invention composition to about 5-50 Pa.s normally. In addition, the viscosity said here is a viscosity in 20 rpm by a BH type viscometer, and measurement temperature is 23 degreeC.

The foamable fire-resistant paint of the present invention can exert its effect by being applied and laminated on an object to be imparted with fire resistance. Examples of the object to be coated include a wall, a pillar, a floor, a beam, a roof, and a staircase. Such an object to be coated is formed of a base material such as concrete or steel, and may be subjected to rust prevention treatment or the like. In addition, an undercoat layer having crosslinkability can be laminated on the article to be coated.
The foamable fireproof paint of the present invention can be applied not only to concrete and steel materials but also to base materials for wooden members, resin-based members and the like. Since the foamable fireproof paint of the present invention is a paint using water as a medium, there is no risk of lifting or the like even if it is applied to an article having an old paint film, and it is suitable for repainting.

  When applying the fire-resistant fire-resistant paint to the object to be coated, it may be applied once or several times using a coating device such as a spray, a roller, a brush, a trowel or a spatula. At the time of painting, the paint can be diluted with water as necessary. The film thickness of the foamable fireproof paint finally formed may be appropriately set depending on the desired fireproof performance, application site, and the like, but is usually about 0.2 to 5 mm.

  In this invention, in order to protect the coating film formed with a foamable fireproof coating material, an overcoat layer can also be laminated | stacked as needed. Such an overcoat layer can be formed by applying a known water-based or solvent-type paint. As the overcoat layer, for example, an acrylic resin-based, urethane resin-based, acrylic silicon resin-based, or fluororesin-based paint can be used, and those having reactivity with the foaming fireproof paint are preferable. These coatings may be performed by a known coating method, and a coating tool such as a spray, a roller, or a brush can be used.

  Examples and Comparative Examples are shown below to clarify the features of the present invention. However, the scope of the present invention is not limited to these examples.

(Example)
(Synthesis Example 1)
145 parts by weight of water, 4 parts by weight of sodium dodecyl sulfate, 0.5 part by weight of ammonium persulfate and the monomers shown in Synthesis Example 1 in Table 1 (total 100 parts by weight) were mixed and emulsified at 80 ° C. for 3 hours in a nitrogen atmosphere. Polymerization was performed to produce an emulsion. The synthetic resin emulsion obtained by the above method had a solid content of 41% by weight and an average particle size of 130 nm. Among the monomers shown in Table 1, hydrophobic monomers having a water solubility of 1 g / 100 ml or less are styrene (water solubility 0.03 g / 100 ml), cyclohexyl methacrylate (water solubility less than 0.01 g / 100 ml), n -Butyl acrylate (water solubility 0.14 g / 100 ml). The water solubility of methyl methacrylate is 1.6 g / 100 ml.

(Synthesis Examples 2 to 4)
A synthetic resin emulsion was produced in the same manner as in Synthesis Example 1 except that the monomer composition shown in Table 1 was used. The properties of the resulting synthetic resin emulsion are shown in Table 1.

(Synthesis Example 5)
145 parts by weight of water, 2 parts by weight of an anionic reactive emulsifier, 2 parts by weight of a nonionic reactive emulsifier, 0.5 parts by weight of ammonium persulfate, and the monomers (total 100 parts by weight) shown in Synthesis Example 5 in Table 1 were mixed. Then, emulsion polymerization was carried out at 80 ° C. for 3 hours under a nitrogen atmosphere to produce a synthetic resin emulsion. The properties of the resulting synthetic resin emulsion are shown in Table 1.

(Synthesis Example 6)
A synthetic resin emulsion was produced in the same manner as in Synthesis Example 1 except that the monomer composition shown in Table 1 was used. The properties of the resulting synthetic resin emulsion are shown in Table 1.

(Synthesis Example 7)
A synthetic resin emulsion was produced in the same manner as in Synthesis Example 5 except that the monomer composition shown in Table 1 was used. The properties of the resulting synthetic resin emulsion are shown in Table 1.

(Synthesis Example 8)
A synthetic resin emulsion was produced in the same manner as in Synthesis Example 1 except that the monomer composition shown in Table 1 was used. The properties of the resulting synthetic resin emulsion are shown in Table 1.

(Synthesis Example 9)
A synthetic resin emulsion was produced in the same manner as in Synthesis Example 5 except that the monomer composition shown in Table 1 was used. The properties of the resulting synthetic resin emulsion are shown in Table 1.

(Synthesis Examples 10-12)
A synthetic resin emulsion was produced in the same manner as in Synthesis Example 1 except that the monomer composition shown in Table 1 was used. The properties of the resulting synthetic resin emulsion are shown in Table 1.

(Paint production example 1)
For 244 parts by weight of the synthetic resin emulsion of Synthesis Example 1 (100 parts by weight of solid content), 244 parts by weight of ammonium polyphosphate, 50 parts by weight of dipentaerythritol, 63 parts by weight of titanium dioxide, 70 parts by weight of water, film-forming aid 14 Part by weight, 10 parts by weight of a dispersant, 2 parts by weight of an antifoaming agent, and 1 part by weight of a viscosity modifier were uniformly mixed and stirred by a conventional method to produce a foamable fire-resistant paint 1.
(Paint production examples 2 to 20)
Except for using the formulations shown in Tables 2 and 3, foamable refractory paints 2 to 20 were produced in the same manner as in Paint Production Example 1.

<Performance evaluation 1>
(Test Examples 1 to 20)
The following various tests were performed using the above-mentioned foamable fireproof coatings 1-20. The results are shown in Tables 4 and 5.

(Foaming ratio)
A paint was applied to a black skin steel plate with a wet film thickness of 2 mm using a film applicator, and cured for 7 days in an atmosphere at a temperature of 23 ° C. and a relative humidity of 50% (hereinafter referred to as “standard state”) to obtain a test specimen. This test body was heated at 650 ° C. for 15 minutes, and the expansion ratio based on the initial film thickness was measured. The evaluation criteria for the expansion ratio in this test are “◎” for an expansion ratio of 15 times or more, “O” for an expansion ratio of 10 times to less than 15 times, “△” for an expansion ratio of 5 times to less than 10 times, An expansion ratio of less than 5 was defined as “x”.

(Denseness)
The test body for which the expansion ratio was measured was cut, and the denseness of the foamed carbonized layer in the cross section was visually confirmed. The evaluation criteria were “◎” for high denseness, “◯” for slightly denseness, and “X” for low denseness.

(water resistant)
A paint was applied to a black skin steel plate coated with rust prevention in advance with a film applicator at a wet film thickness of 1 mm, and cured for 7 days in a standard state to obtain a test specimen. After this test body was immersed in water at 23 ° C. for 3 days, the surface state of the coating film was visually confirmed. The evaluation criteria are “◎” for the case where no blister was observed, “◯” for the blister generation area of less than 10%, and “△” for the blister generation area of 10% to less than 20%. In addition, the case where the blister generation area was 20% or more was designated as “x”.

(Storage stability)
250 ml of the prepared paint was put into a 300 ml cup and sealed, and then stored in a thermostatic bath at 50 ° C. for 30 days, and a change in viscosity before and after storage was confirmed. The evaluation criteria are “◎” for a viscosity change rate of less than 10%, “◯” for a viscosity change rate of 10% to less than 20%, “Δ” for a viscosity change rate of 20% to less than 50%, and a viscosity change rate of 50%. The above was designated as “x”.

<Performance evaluation 2>
(Test Examples 21 to 23)
Further, the following various tests were performed on the foamed fire resistant paints 16 to 18. The results are shown in Table 6.
(Mechanical stirring stability test)
After measuring the initial viscosity of the prepared paint, stirring was continued for 60 minutes at 1800 revolutions per minute, stirring was stopped, and the viscosity was measured after stirring. At this time, the viscosity change was confirmed by comparing the initial viscosity and the viscosity after stirring. The evaluation criteria are “◎” for a viscosity change rate of less than 10%, “◯” for a viscosity change rate of 10% to less than 20%, “Δ” for a viscosity change rate of 20% to less than 50%, and a viscosity change rate of 50%. The above was designated as “x”. In addition, a viscosity measurement is a viscosity in 20 rpm by a BH type viscometer, and measurement temperature is 23 degreeC.

(Low temperature water resistance)
A paint was applied to a black skin steel plate coated in advance with rust prevention with a film applicator with a wet film thickness of 1 mm and cured at 5 ° C. for a certain period of time to obtain a test specimen. After this test body was immersed in water at 23 ° C. for 1 day, the surface state of the coating film was visually confirmed. The results are shown in Table 6. Evaluation criteria evaluated the number of days of curing until the occurrence of blisters was not observed.

(Adhesion strength)
A paint was applied to a black skin steel plate coated in advance with rust prevention with a film applicator at a wet film thickness of 2 mm, and cured for 7 days in a standard state to obtain a test specimen. Based on the JIS K 5400 8.7 adhesion strength test method, a steel jig having a size of 40 mm × 40 mm was bonded to the test specimen with a two-pack type epoxy resin adhesive. 24 hours later, along the steel jig, the periphery is cut to a size of 40 mm × 40 mm until it reaches the black skin steel plate, and the sample surface is vertically aligned with the steel jig and steel plate for lower tension. The maximum tensile load was determined by applying a tensile force with an autograph.

Claims (3)

  In the foamable refractory paint containing a synthetic resin emulsion, a phosphorus compound, a polyhydric alcohol and a filler, the synthetic resin emulsion has a hydroxyl group as a functional group, and the hydroxyl value in the resin solid content is 0.1 to 100 mgKOH / g. A foaming fireproof paint characterized by being.   The synthetic resin emulsion is an emulsion polymer of a monomer group mainly composed of (meth) acrylic acid alkyl ester and / or an aromatic monomer, and the ratio of the hydroxyl group-containing monomer in the monomer group is 0.5 to 15% by weight. The foamable refractory paint according to claim 1, wherein   The foamable fire-resistant paint according to claim 1 or 2, wherein the synthetic resin emulsion contains 50% by weight or more of a hydrophobic monomer having a water solubility of 1 g / 100 ml or less in a monomer group.