JP2001106982A - Formable type fireproof coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a foamable type fireproof coating capable of forming a hardy falling and uniform foamed layer by control of foaming, providing the foamed layer having sufficient strength, excellent adhesivity to a steel substrate, providing excellent fire resistance performances in a thin coating film. SOLUTION: This foamable type fireproof coating is a coating comprising a polyhydric alcohol, a flame-retardant blowing agent and a synthetic resin as main components. The flame-retardant blowing agent is ammonium phosphate and/or ammonium polyphosphate. A synthetic resin having <=25 deg.C decomposition starting temperature in which >=50 wt.% and <=90 wt.% total solid content is decomposed up to 300 deg.C is used as the synthetic resin. The polyhydric alcohol is at least one or more kinds of pentaerythritol, dipentaerythritol, tripentaerythritol and a polypentaerythritol. The coating preferably contains a nitrogen-containing blowing agent in a coating component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a fireproof covering material used for protecting steel materials used for steel columns and beams from fire. The present invention relates to a foam type refractory paint for forming a heat insulating layer.

[0002]

2. Description of the Related Art Conventionally, foam-type refractory paints have been applied in a thin film of about 2 mm to obtain fire-resistant performance.
Applied to steel used for beams. The applied steel material foams when exposed to a fire to form a heat insulating layer.

[0003]

However, it is difficult to control the foaming of the conventional foamed refractory paint, and the foamed layer falls off due to excessive foaming, and the foamed layer cracks due to uneven foaming. Also, due to the brittleness of the adhesion of the foam layer to the steel frame base and the lack of strength of the foam layer itself, sufficient fire resistance may not be exhibited.

[0004] The present invention has been made by focusing on the problems existing in the prior art as described above. Its purpose is to control the foaming, it is difficult to fall off, it is possible to form a uniform foamed layer, the foamed layer has sufficient strength, excellent adhesion to the steel frame base, excellent fire resistance in thin film A foam type refractory paint capable of obtaining performance (the time required for the back surface temperature of a specimen coated with a 2 mm thick refractory paint to reach 500 ° C. in a heating test according to JIS A 1304 is 45 minutes or more) To provide.

[0005]

In order to achieve the above-mentioned object, a foam type refractory paint according to the first aspect of the present invention is a paint containing a polyhydric alcohol, a flame-retardant foaming agent, and a synthetic resin as main components. Wherein the flame-retardant blowing agent is ammonium phosphate and / or ammonium polyphosphate, and the decomposition start temperature of the synthetic resin is 250 ° C. or less,
A synthetic resin is used in which 50% by weight or more and 90% or less of the total solid content is decomposed by 0 ° C.

[0006] In the foamed refractory paint according to the second aspect of the present invention, the polyhydric alcohol is at least one kind selected from the group consisting of pentaerythritol, dipentaerythritol, tripentaerythritol and polypentaerythritol. It is something that is.

[0007] The foam type refractory paint according to the third aspect of the present invention is the one according to the first or second aspect, wherein the paint component contains a nitrogen-containing blowing agent.

[0008] The foam type refractory paint of the invention according to claim 4 is a paint containing a polyhydric alcohol, a flame retardant foaming agent, a synthetic resin as a main component or a polyhydric alcohol, a flame retardant foaming agent, a synthetic resin, In a paint containing a nitrogen-containing blowing agent as a main component, at least one of a polyhydric alcohol, a flame-retardant blowing agent, and a nitrogen-containing blowing agent is microencapsulated.

The foam type refractory paint according to the fifth aspect of the present invention is the one according to any one of the first to fourth aspects, wherein the paint component contains titanium dioxide.

The foam type refractory paint according to the invention described in claim 6 is the invention according to any one of claims 1 to 5, wherein the paint component contains expandable graphite.

[0011] In the foamed refractory paint of the invention according to claim 7, the coating material at the time of microencapsulation is melamine, ethyl cellulose, cellulose nitrate, It is arbitrarily selected from polymethyl methacrylate, polystyrene, epoxy resin, acrylonitrile-styrene copolymer, cellulose acetate phthalate, vinylidene chloride-acrylonitrile copolymer, and polyvinyl formal.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The individual elements of the present invention will be described below. The foam type refractory paint is a paint containing a polyhydric alcohol, a flame retardant foaming agent, and a synthetic resin as main components, and the flame retardant foaming agent is ammonium phosphate and / or
Alternatively, a synthetic resin which is ammonium polyphosphate and has a decomposition initiation temperature of the synthetic resin of 250 ° C. or less and which decomposes at least 50 wt% to 90% of the total solids by 300 ° C. is used.

The polyhydric alcohol is a component which is dehydrated and condensed with a flame-retardant foaming agent which will be described later, and forms a foamed layer by the decomposition gas of the flame-retardant foaming agent and the nitrogen-containing foaming agent. As polyhydric alcohols, pentaerythritol, dipentaerythritol, tripentaerythritol, polypentaerythritol, triethylene glycol, sorbitol, resorcinol, glycerin, trimethylolmethane, trimethylolpropane, diethyleneglycol,
Examples include propylene glycol and hexamethylene glycol. Of these examples, pentaerythritol having a decomposition temperature of 260 ° C. to decompose at substantially the same temperature as the flame-retardant foaming agent and form a foamed layer,
Dipentaerythritol, tripentaerythritol,
It is preferred to use a polyhydric alcohol selected from polypentaerythritol.

By using a polyhydric alcohol selected from pentaerythritol, dipentaerythritol, tripentaerythritol and polypentaerythritol, a more stable foamed layer can be formed. In particular, pentaerythritol, dipentaerythritol and dipentaerythritol It is more preferable to use

[0015] The component flame retardant blowing agent must use ammonium phosphate and / or ammonium polyphosphate. These flame-retardant blowing agents generate ammonia gas and at the same time lower the temperature of the painted surface by an endothermic reaction. These decomposition temperatures are 275 ° C., and the dehydration and condensation reaction with polyhydric alcohol in the temperature range of 250 ° C. to 300 ° C. proceeds efficiently.

The synthetic resin as a component plays a role in providing adhesion and weather resistance of the coating film at normal temperature. In synthetic resin,
A decomposition starting temperature of 250 ° C. or less and a substance that decomposes 50% by weight or more and 90% by weight or less of the total solids by 300 ° C. must be used. Decomposition start temperature is 250 ° C
Those which decompose only 50 wt% or less of the total solid content by 300 ° C. prevent the flame-retardant foaming agent and polyhydric alcohol from dehydrating and condensing, so that a sufficient foamed layer cannot be formed.
If the total solid content is decomposed by 90% by weight or more by 300 ° C., the foamed layer becomes brittle due to excessive foaming, and easily falls off. The decomposition temperature of ammonium phosphate and / or ammonium polyphosphate used as a flame-retardant foaming agent is 275 ° C., and the decomposition temperature of a polyhydric alcohol which is preferably selected is 260 ° C .; The above-mentioned ones, in which 50 wt% to 90 wt% of the total solids are decomposed by 300 ° C., can form a sufficient foamed layer, and the foamed layer becomes brittle due to excessive foaming, and does not easily fall off. , It will be balanced.

Examples of the synthetic resin include melamine resin, acrylic resin, alkyd resin, vinyl chloride resin, vinyl acetate resin, urethane resin, epoxy resin, silicone resin,
There are polyester resins and the like. These resins may be used alone or may be copolymerized, and may be used as a mixture. Further, as the form of these resins, those dissolved in an organic solvent or those dispersed in water as an emulsion can be used. It is also possible to add a plasticizer such as trichlorophosphate or texanol to the synthetic resin to control the decomposition characteristics within the above range.

As the synthetic resin, a synthetic resin emulsion dispersed in water as an emulsion is preferably used. Synthetic resin emulsions are easy to obtain and to produce foamed refractory paints.

The nitrogen-containing blowing agent of the component includes, for example, dicyandiamide, azodicarbonamide, melamine and derivatives thereof exemplified by trimethylolmelamine, hexamethylolmelamine and hexamethoxymethylmelamine, urea, butylurea, dimethylurea and guanylureaphos. Fate, aminoguanylurea, urea formaldehyde, aminoacetic acid, guanidine and the like can be used. Among these, melamine and its derivatives having a decomposition temperature of 370 ° C. are preferably used in view of the control of two-stage foaming in which the expansion ratio is increased again at a temperature different from the decomposition temperature of the flame-retardant foaming agent.

The polyhydric alcohol, a flame-retardant blowing agent,
Preferably, one or more of the nitrogen-containing blowing agents are microencapsulated. Many polyhydric alcohols, flame-retardant foaming agents, and nitrogen-containing foaming agents are hydrophilic, and the water resistance of the coating film formed by the foamed refractory paint is reduced, which may impair the fire resistance performance. For this reason, melamine, ethyl cellulose, cellulose nitrate, polymethyl methacrylate, polystyrene, epoxy resin, acrylonitrile-styrene copolymer, cellulose acetate phthalate, vinylidene chloride-acrylonitrile copolymer, polyvinyl formal, etc. Encapsulation is preferred. By microencapsulation with a coating material having excellent water resistance, even a polyhydric alcohol, a flame retardant foaming agent, and a nitrogen-containing foaming agent, which are hydrophilic and have poor water resistance, can be used.

A melamine resin or a polystyrene resin is preferably used because of more complete coating, water resistance, strength of the encapsulated product and fineness of the capsule. Methods for microencapsulating polyhydric alcohols, flame-retardant foaming agents, and nitrogen-containing foaming agents include interfacial polymerization, in situ polymerization, in-liquid curing coating, coacervation, interfacial precipitation, spray drying, A known microencapsulation method such as an inorganic wall encapsulation technique can be used. Hereinafter, microencapsulation methods will be described by taking hydrophilic pentaerythritol as an example.

First, in the interfacial polymerization method, an aqueous solution of pentaerythritol containing a water-soluble monomer such as polyamine, glycol or polyhydric phenol is dispersed as fine droplets in an organic solvent insoluble in water. An oil-soluble monomer such as haloformate or polyisocyanate is added and stirred. Then, a polymerization reaction of the two types of monomers occurs at the interface between water and the organic solvent, and microcapsules are obtained. The in situ polymerization method is a method in which a powder or aqueous solution of pentaerythritol is dispersed in a monomer, and a polymerization catalyst is added to form a film on the surface of pentaerythritol.

In the in-liquid curing coating method, a powder or aqueous solution of pentaerythritol is encapsulated with a polymer film, and the film is cured with a curing agent. In this case, examples of the combination of the polymer film and the curing agent include sodium alginate and calcium chloride, polyvinyl alcohol and borax, and epoxy resin and boron tetrafluoride.

The coacervation method includes the steps of ethyl cellulose, cellulose nitrate, polymethyl methacrylate, polystyrene, epoxy resin, acrylonitrile-styrene copolymer, cellulose acetate phthalate, vinylidene chloride
After dissolving a film material such as an acrylonitrile copolymer and polyvinyl formal in a solvent such as toluene-ethanol, methyl ethyl ketone, acetone, benzene, nitropropane, dioxene, tetrahydronaphthalene, toluene, toluene-ethanol-ethylene acetate, the organic solvent Add pentaerythritol to the mixture and disperse well. To this, a polymer for inducing phase separation such as polybutadiene, polydimethylsiloxane, phenylmethylsiloxane, and methacrylic polymer is added to cause phase separation. The phase-separated capsule is pulverized by drying under reduced pressure or the like.

In the interfacial precipitation method, a pentaerythritol aqueous solution is stirred in a hydrophobic polymer solution to obtain a uniform dispersion. The dispersion is dropped and dispersed in an aqueous protective colloid solution, and the capsule is repaired by a method such as decompression, drying, filtration and sedimentation. At this time, the hydrophobic polymer becomes the coating substance. Examples of the hydrophobic polymer in the interface precipitation method include polystyrene, polycarbonate, ethyl cellulose, a vinyl acetate-ethylene copolymer, a phenylsiloxane ladder polymer, a vinylidene chloride-acrylonitrile copolymer, and the like. Vinyl, vinylidene chloride acrylate, vinyl ester, methacrylate, polymer or copolymer such as acrylonitrile,
Examples include polycondensates such as soluble polycarbonate, polyester, polysulfonate, polyurethane and polyamide, chlorinated natural rubber, and cellulose derivatives. In addition, methylene chloride,
Benzenecyclohexane, carbon tetrachloride, cyclohexanone and the like can be mentioned.

In the spray drying method, a stock solution for encapsulation is sprayed and dried by hot air. This stock solution for encapsulation is a suspension in which pentaerythritol is uniformly dispersed in a polymer, and a polymer film is adhered to the surface by hot-air drying. The mineral wall encapsulation technique deposits a hydrophobic powder, such as talc, clay, aerosil, calcium stearate, aluminum stearate, on the surface of pentaerythritol.

The method of microencapsulation can be performed by any method, but the method of microencapsulation by the interfacial precipitation method, spray drying method, or inorganic wall encapsulation technique is preferable from the viewpoint of easy production of microcapsules. . In particular, the interfacial precipitation method can be used for most polymers, and is more preferably used because the adjustment is relatively easy and the control of the capsule film thickness is easy.

By microencapsulating one or more of a polyhydric alcohol, a flame-retardant blowing agent and a nitrogen-containing blowing agent, the water resistance of the main component of the foamed refractory paint can be improved, and Can be suitably used in a site where occurs.

It is also possible to add titanium dioxide as a component to the foam type refractory paint of the present invention. By the addition of titanium dioxide, the bonding of the foamed layer is promoted by its catalytic effect, and a foamed layer with high shape retention is formed. The crystal forms of titanium dioxide include anatase type and rutile type, and anatase type titanium dioxide is preferably used. The catalytic effect is further promoted by the anatase type titanium dioxide.

In addition, it is also possible to add expandable graphite as a component. By adding the expandable graphite, a paint having a thinner film and higher fire resistance can be obtained. The coating film to which the expandable graphite is added expands rapidly by heating at the time of fire or the like, thereby improving the heat insulating performance of the foamed layer. The expandable graphite has a property that when heated, the compound existing between the graphite layers thermally decomposes and the whole expands. Examples of such expandable graphite include graphite acid sulfate, sodium graphite, potassium graphite, halogenated graphite,
Graphite oxide, aluminum chloride graphite compound, ferric chloride graphite and the like can be mentioned.

The foamed refractory paint of the present invention may contain, in addition to the above-mentioned main components, components contained in conventional paints or refractory paints, as long as the effects of the present invention are not impaired. Its components include calcium carbonate,
Fillers such as aluminum hydroxide, alumina, silica, inorganic fibers, rock wool, flame retardants such as halogen, phosphorus and antimony trioxide, and surfactants such as defoamers, dispersants, and wetting agents. Solvents such as film assistants and antifreezing agents, coloring pigments, extender pigments, metal soaps, stabilizers, thickeners for adjusting viscosity and viscosity, preservatives, and fungicides.

The foam type refractory paint is prepared as described above and applied to a painted surface such as a steel frame. This foam type refractory paint is applied by a normal paint application method such as brush, spray, etc.
In addition to being able to be painted, it is also possible to work with irons and rollers. Application by spraying is preferably performed from the working efficiency. In addition, a bolt portion used for fixing a steel frame is often applied with a brush.

This foam type refractory paint is not only steel
It is suitably used for aluminum, zinc iron plate, asbestos cement plate and the like. It is also useful for making flammable substances such as wood, plywood, paper, fiber, etc. semi-flammable or flame-retardant. Other than that, it is also effective for covering electric cables. When applying the foamed refractory paint, it is also possible to apply a primer treatment or, in the case of steel, an undercoat with a rust preventive paint or the like, and then apply the foamed refractory paint. After the undercoat is applied, the foamed refractory paint is applied with the foamed refractory paint of the present invention, and then the intermediate coat and the top coat can be applied for the purpose of improving the appearance and durability.

Next, a method for measuring the fire resistance performance of the foamed refractory paint constructed as described above will be described. Now, STKR400 specified in JIS G 3466 which has been blasted
Square steel pipe for square general structures (height: 300 mm, width: 300 mm)
A square-shaped steel pipe having a thickness of 9 mm) and a length of 1000 mm is spray-coated with a foamed refractory paint to a thickness of 2 mm and cured for 21 days to prepare a test body. This test specimen is JIS A1
A heating test was performed according to a standard heating curve of No. 304, and the back surface temperature of the steel material was measured with a K thermocouple.

The evaluation of this test piece was conducted when the back surface temperature of the steel material was 5%.
The observation is performed by observing the time (minutes) when the temperature reaches 00 ° C. and the appearance of the test specimen after the completion of heating. As described above, according to this embodiment, the following effects are exhibited.

The foam type refractory paint is a paint containing a polyhydric alcohol, a flame retardant foaming agent and a synthetic resin as main components, wherein the flame retardant foaming agent is ammonium phosphate and / or
Alternatively, foaming is performed by using a synthetic resin that is ammonium polyphosphate and has a decomposition initiation temperature of 250 ° C. or less and decomposes 50% to 90% of the total solid content by 300 ° C. With this control, it is possible to form a uniform foamed layer that is difficult to fall off, and that the foamed layer has sufficient strength, excellent adhesion to a steel frame substrate, and excellent fire resistance performance in a thin film.

The flame-retardant blowing agent is ammonium phosphate and / or ammonium polyphosphate, and the dehydration and condensation reaction with polyhydric alcohol proceeds efficiently. Further, the decomposition starting temperature of the synthetic resin is 250 ° C. or less, and 50% by weight or more of the total solids by 300 ° C.
By using a synthetic resin that decomposes at 0% or less, a sufficient foamed layer can be formed without hindering the dehydration condensation of the flame-retardant foaming agent and the polyhydric alcohol. In addition, the foam layer becomes brittle due to excessive foaming, and the foam layer hardly falls off.

When the polyhydric alcohol is at least one of pentaerythritol, dipentaerythritol, tripentaerythritol and polypentaerythritol, the decomposition temperature is 260 ° C., and ammonium polyphosphate and / or ammonium polyphosphate It decomposes at almost the same temperature as the flame-retardant foaming agent to form a foamed layer, so that a stable foamed layer can be formed.

A more stable foamed layer can be formed by including a nitrogen-containing foaming agent in the coating component.

Polyhydric alcohols, flame-retardant blowing agents,
In a paint containing a synthetic resin as a main component or a paint containing a polyhydric alcohol, a flame-retardant foaming agent, a synthetic resin, and a nitrogen-containing foaming agent as a main component, a polyhydric alcohol, a flame-retardant foaming agent, a nitrogen-containing foaming When one or more of the agents are microencapsulated, the water resistance of the coating film formed by the foam type refractory paint may decrease, and the fire resistance may be impaired.

When the coating composition contains titanium dioxide, the bonding of the foamed layer is promoted by the catalytic effect of titanium dioxide, and a foamed layer having a high shape-maintaining property is formed.

By adding the expandable graphite as a component, a paint having a thinner film and higher fire resistance can be obtained.

The foam type refractory paint is such that the coating material when microencapsulated is melamine, ethyl cellulose,
Cellulose nitrate, polymethyl methacrylate, polystyrene, epoxy resin, acrylonitrile-styrene copolymer, cellulose acetate phthalate, vinylidene chloride-acrylonitrile copolymer, by being arbitrarily selected from polyvinyl formal, hydrophilic and water resistant Inferior ones can be used.

When the nitrogen-containing blowing agent is melamine or a derivative thereof, the expansion ratio can be increased again at a temperature different from the decomposition temperature of the flame-retardant blowing agent, and two-stage foaming can be performed.

The catalytic effect is further promoted by the titanium dioxide being an anatase type.

[0046]

EXAMPLES Examples and comparative examples are shown below to further illustrate the fire-resistant paint of the present invention. However, these examples are intended to illustrate the present invention, but not to limit it. First, the following Table 1 shows the formulation examples of Examples and Comparative Examples. In addition, FIGS. 1 to 4 below show temperature-weight curves of synthetic resin components used in Examples and Comparative Examples by TG (thermogravimetry).

The sample in the TG was approximately 10 mg. The temperature rise rate in TG is 1 from normal temperature to 100 ° C.
The temperature is raised at a rate of 10 ° C. per minute,
Hold for 0 min. Similarly, 10 ° C / 100 ° C to 200 ° C
Min, hold for 60 minutes, 10 ° C / 200 ° C to 250 ° C
Min, hold for 60 minutes, 10 ° C /
Min, hold for 30 minutes, 10 ℃ / 300 ℃ to 350 ℃
Min, hold for 30 minutes, 10 ° C / 350 ° C to 400 ° C
Min, hold for 30 minutes, 10 ° C /
Min, hold for 60 minutes, 10 ℃ from 500 ℃ to 1000 ℃
/ Min, and the test was terminated when the temperature of the specimen reached 1000 ° C. The synthetic resin 1 was a vinyl acetate resin, the synthetic resin 2 was a vinyl acetate-veova resin, the synthetic resin 3 was an acrylic resin, and the synthetic resin 4 was a vinyl acetate-acrylic resin.

The synthetic resin 1 and the synthetic resin 2 have a decomposition initiation temperature of 250 ° C. or less, and decompose 50% to 90% of the total solids by 300 ° C.
The synthetic resin 3 has a decomposition start temperature of 250 ° C. or higher and decomposes by less than 10% of the total solid content by 300 ° C. The synthetic resin 4 has a decomposition start temperature of 250 ° C.
It can be seen from FIGS. 1 to 4 that the synthetic resin decomposes 90% or more of the total solid content by 300 ° C. or less at 300 ° C. or less.

Hereinafter, Table 1 shows the composition examples of Examples 1 to 6, and Table 2 shows the composition examples of Comparative Examples 1 to 4. In addition, the synthetic resin was represented by solid content, and represented by parts by weight.

[Table 1]

[Table 2]

STKR400 square steel pipe for general structure stipulated in JIS G3466 which has been blasted and has a length of 300 mm, a width of 300 mm, a thickness of 9 mm and a length of 1000
A 2 mm thick square steel pipe is sprayed with a foamed refractory paint having a composition of an example or a comparative example to a thickness of 2 mm.
The specimen was cured for one day. When applying the refractory paint, dilute each paint and use a viscosity of 3
It adjusted so that it might be set to 0-35 dPa * s. The test body was subjected to a heating test according to the standard heating curve of JIS A1304, and the back surface temperature of the steel material was measured with a K thermocouple.

The evaluation was performed by observing the time when the back surface temperature of the steel material reached 500 ° C. and the appearance of the specimen after the completion of heating. Regarding the appearance of the test piece, the presence or absence of cracks in the foam layer and the falling off of the foam layer were visually confirmed. Cracks in the foam layer are as follows: those without any cracks: 発 生, those having cracks and having a width of less than 1 mm ... △, those having a crack width of 1 mm or more ... ×,
No dropouts: ○, less than 20% of the total drops off… △, 20% or more of the total drops off…
It was represented as x.

Table 3 shows the test results of Examples 1 to 6.
Table 4 shows the test results of Comparative Examples 1 to 4.

[Table 3]

[Table 4] *: Measurement is not possible because the foam layer has fallen off.

Further, a foamed refractory paint was obtained by microencapsulating pentaerythritol and ammonium polyphosphate. As the synthetic resin, a styrene-acrylic resin was used. Table 5 shows formulation examples of Examples 7 to 12, and Table 6 shows formulation examples of Comparative Examples 5 to 8. In addition, the synthetic resin was represented by solid content, and represented by parts by weight.

[Table 5]

[Table 6]

As a method of microencapsulation, microcapsules 1 and 2 were prepared by the interfacial precipitation method, microcapsules 3 were obtained by spray drying, and microcapsules 4 were obtained by an inorganic wall encapsulation technique. . Microcapsules 1 were prepared as a hydrophobic polymer solution in methylene chloride 50 ml and polystyrene 5
pentaerythritol solution 50ml in the dissolved solution
In addition, the mixture was stirred at 40 ° C. for 30 minutes to obtain a uniform dispersion.
This dispersion was added dropwise to a 1% gelatin solution as an aqueous protective colloid solution, and the mixture was stirred for 1 hour. Then, the pressure was reduced while stirring, the methylene chloride was evaporated, and the resulting microcapsules were dried at room temperature. The coating of the microcapsules was cured. After the coating was cured, the gelatin remaining on the surface was washed and dried again to obtain pentaerythritol encapsulated.

The microcapsules 2 were prepared by adding 15 g of pentaerythritol to 200 ml of a 15% by weight benzene solution of polymethyl methacrylate, followed by stirring at 25 ° C. for 5 minutes. 500 ml of polydimethylsiloxane is added to this solution.
In addition, stirring was further continued for 1 hour, and after completion of the stirring, the liquid temperature was kept at 4 ° C. and allowed to stand for 24 hours. The supernatant liquid after standing was removed, washed again with benzene, and dried under reduced pressure. Thereafter, the microcapsules were dried at 60 ° C. to obtain microcapsules.

The microcapsules 3 were prepared by using a 20 wt% xylene solution of a vinyl acetate resin as the encapsulating stock solution, and adding 20 g of pentaerythritol to 100 ml of the solution.
A suspension was prepared in which the pentaerythritol particles were uniformly dispersed. The suspension was sprayed in a drying chamber, dried, and microencapsulated.

Microcapsules 4 were obtained by adding 40 g of aluminum stearate to 100 g of pentaerythritol and stirring for 1 hour with a mixer to obtain microcapsules.

The microcapsules 5 are obtained by microencapsulating ammonium polyphosphate.
The one made by Clariant was used.

Specimens were prepared from the foamed refractory paints of Examples 7 to 12 and Comparative Examples 5 to 8, and the heating test was performed while changing the immersion time.

The test piece was blasted to a length of 300 mm.
Example 7 to SS400 steel sheet 300 mm wide and 9 mm thick
The foamed refractory paints of Example 12 and Comparative Examples 5 to 8 were applied to a thickness of 2 mm by spraying and cured. The curing conditions were a room temperature of 20 ° C. and a humidity of 65% RH.

Six test specimens were prepared, and the immersion time before the heating test was set to 4, 8, 24, 48 hours and 1 week. Epoxy resin was applied to the four side surfaces and the back surface of each specimen to prevent rust of the steel plate.

The heating test after immersion was performed according to JIS A1304.
According to the standard heating curve, the time when the back surface temperature of the steel sheet reached 500 ° C. and the thickness of the foamed layer in the appearance of the test body after the heating were measured using a K thermocouple. Tables 7 and 8 show the time when the back surface temperature reached 500 ° C., and the unit of time is expressed in minutes. Tables 9 and 10 show the thickness of the foam layer, and the unit is mm.

[Table 7]

[Table 8]

[Table 9]

[Table 10]

In Comparative Examples 5 to 8, since the polyhydric alcohol pentaerythritol, which is hydrophilic, was not microencapsulated, the foamed layer had a low foaming height and the fire resistance was low in the test piece after water immersion. It can be seen that has decreased. In Examples 7 to 11, since pentaerythritol was microencapsulated, no decrease in fire resistance after immersion was observed.

[0064]

The present invention is configured as described above, and has the following effects. According to the foam type refractory paint according to the first aspect of the present invention, by controlling foaming, it is difficult to fall off, a uniform foamed layer can be formed, the foamed layer has sufficient strength, and adheres to a steel frame substrate. Excellent in fire resistance, excellent fire resistance performance in thin film, dehydration and condensation reaction proceed efficiently, do not hinder dehydration condensation of flame-retardant blowing agent and polyhydric alcohol, and form sufficient foam layer Can be. In addition, the foam layer becomes brittle due to excessive foaming, and the foam layer hardly falls off.

According to the foam type refractory paint of the invention of the second aspect, in addition to the effect of the first aspect of the invention, the decomposition temperature is 260 ° C., and ammonium phosphate and / or ammonium polyphosphate is hardly used. It decomposes at almost the same temperature as the flame-forming foaming agent to form a foamed layer, so that a stable foamed layer can be formed.

According to the foam type refractory paint of the invention described in claim 3, in addition to the effects of the invention described in claim 1 or claim 2, a more stable foam layer can be formed.

According to the foamed refractory paint of the present invention, the water resistance of the coating film formed by the foamed refractory paint is improved, and the fireproof performance is not impaired.

According to the foamed refractory paint of the invention described in claim 5, in addition to the effects of the invention described in any one of claims 1 to 4, the bonding of the foamed layer is promoted by the catalytic effect of titanium dioxide. As a result, a foam layer having a high shape maintaining property is formed.

According to the foamed refractory paint of the invention described in claim 6, in addition to the effects of the invention described in any one of claims 1 to 5, a paint having a thinner film and higher fire resistance can be obtained.

According to the foamed refractory paint of the invention described in claim 7, in addition to the effects of the invention described in any of claims 4 to 6, a polyhydric alcohol, a flame-retardant foaming agent or a nitrogen-containing foam is used. Even if the components of the foaming agent are hydrophilic and have poor water resistance, they can be used, and the water resistance of the foamed refractory paint can be improved.

[Brief description of the drawings]

FIG. 1 shows the temperature of synthetic resin 1 used in Examples.
Weight curve

FIG. 2 shows the temperature of synthetic resin 2 used in Examples.
Weight curve

FIG. 3 shows the temperature of the synthetic resin 3 used in the examples.
Weight curve

FIG. 4 shows the temperature of the synthetic resin 4 used in the examples.
Weight curve

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[Procedure amendment]

[Submission date] October 26, 2000 (2000.10.
26)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction contents]

The synthetic resin as a component plays a role in providing adhesion and weather resistance of the coating film at normal temperature. In synthetic resin,
A decomposition starting temperature of 250 ° C. or less and a substance that decomposes 50% by weight or more and 90% by weight or less of the total solids by 300 ° C. must be used. Decomposition start temperature is 250 ° C
Those which decompose only 50 wt% or less of the total solid content by 300 ° C. prevent the flame-retardant foaming agent and polyhydric alcohol from dehydrating and condensing, so that a sufficient foamed layer cannot be formed.
If the total solid content is decomposed by 90% by weight or more by 300 ° C., the foamed layer becomes brittle due to excessive foaming, and easily falls off. The decomposition temperature of ammonium phosphate and / or ammonium polyphosphate used as a flame-retardant foaming agent is 275 ° C., and the decomposition temperature of a polyhydric alcohol which is preferably selected is 260 ° C .; more are those, those 50 wt% or more 90 wt% of the total solids up to 300 ° C. or less to decompose, sufficient foam layer can be formed, there is no weakness in such Rukoto foam layer by foaming Works too, It is a well-balanced product that does not easily fall off.

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] Figure 2

[Correction method] Change

[Correction contents]

FIG. 2

Claims (7)

[Claims] 1. A polyhydric alcohol, a flame-retardant blowing agent,
In a paint containing a synthetic resin as a main component, the flame-retardant blowing agent is ammonium phosphate and / or ammonium polyphosphate, and the temperature at which the synthetic resin starts to decompose is 250 ° C.
A foam-type refractory paint characterized by using a synthetic resin which decomposes not less than 50% by weight and not more than 90% of the total solid content by 300 ° C. 2. The foam type refractory paint according to claim 1, wherein the polyhydric alcohol is at least one of pentaerythritol, dipentaerythritol, tripentaerythritol and polypentaerythritol. 3. The foam type refractory paint according to claim 1, wherein the paint component contains a nitrogen-containing foaming agent. 4. A polyhydric alcohol, a flame-retardant blowing agent,
Paint or polyhydric alcohol mainly composed of synthetic resin,
A paint mainly composed of a flame-retardant foaming agent, a synthetic resin, and a nitrogen-containing foaming agent, wherein at least one of a polyhydric alcohol, a flame-retardant foaming agent, and a nitrogen-containing foaming agent is microencapsulated. A foam-type fire-resistant paint characterized by having: 5. The foam type refractory paint according to claim 1, wherein the paint component contains titanium dioxide. 6. The foam type refractory paint according to claim 1, wherein the paint component contains expandable graphite. 7. The coating material for microencapsulation is melamine, ethyl cellulose, cellulose nitrate, polymethyl methacrylate, polystyrene, epoxy resin, acrylonitrile-styrene copolymer, cellulose acetate phthalate, vinylidene chloride-acrylonitrile copolymer. The foam type refractory paint according to any one of claims 4 to 6, which is arbitrarily selected from polyvinyl formal.