JP2862419B2 - Foamable fire-resistant paint - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foamed refractory paint which has a stable foaming mechanism when the temperature rises and forms a uniform foamed layer.

[0002]

2. Description of the Related Art Conventionally, a coating material which is applied on a base material such as a steel frame or concrete to delay a rise in the base material temperature when a temperature rises due to a fire or the like and to prevent a sharp decrease in mechanical strength has been developed. Are known. As such a coating material, an inorganic binder such as cement, an inorganic fibrous substance such as rock wool, asbestos, and glass fiber, a lightweight aggregate such as perlite and vermiculite, and an inorganic powder containing water of crystallization are mixed. There is a wet refractory coating material in which a paste or slurry material that is kneaded with water is thickened on the surface of a substrate.
However, this wet refractory coating is 1 cm to 3 cm
Many of them are relatively thick. Therefore, when applying such a coating material at a construction site, a large amount of the coating material must be carried in. In order to give a feeling of oppression, the appearance after the construction was not necessarily beautiful. On the other hand, there is a foamed refractory paint that foams when the temperature rises due to a fire or the like and imparts fire resistance to the substrate. It contains components that decompose due to a rise in temperature and generate non-combustible gas, and components that form a porous carbonized layer by carbonization. The fire extinguishing effect is exhibited by the formation of the porous carbonized layer by the carbonization component to exhibit the heat insulating effect. Since this foamed refractory paint is applied with a thickness of several mm, it is thinner than a wet-type refractory coating material, so that it has a less feeling of oppression and is refreshed. Also, since it is lighter than a wet refractory coating, transportation problems are solved. Therefore, there has been an attempt to use a foamed fire-resistant paint in a part where a building needs to have a certain level of fire resistance and is visible to the public.

[0003]

However, it has become clear that the foamed refractory paint has various problems. In other words, foamed fire-resistant paints exhibit fire-resistant performance in the event of a fire by the above-mentioned action mechanism, but since these actions do not occur until the time of the fire, there is no fire for a long time, and in some cases, a long-term fire In some cases, the function did not work as designed. That is, when the temperature rises when a fire occurs, the coating film may not be foamed uniformly, resulting in the formation of projections due to uneven foaming, or the foamed layer may be softly sagged. In such a state, the fire extinguishing effect of the non-combustible gas and the heat insulation of the carbonized layer function only unevenly. In an extreme case, the foamed layer is peeled off from the base material surface, and the fire resistance performance is reduced. I was

[0004]

Means for Solving the Problems In order to solve such a problem, the present inventors have made intensive studies and as a result, have used a specific resin component among the components of the conventional foamed refractory paint. By specifying the components and ratios of various fillers, it has been found that fire resistance can be improved by uniform foaming. That is, one-pack modified epoxy resin as a binder, ammonium polyphosphate and melamine as a blowing agent, pentaerythritol as a carbon-forming material,
It is composed of an inorganic powder and an inorganic fibrous substance. 100 parts by weight of a one-component modified epoxy resin in terms of solid content is 100 to 600 parts by weight of ammonium polyphosphate, 25 to 300 parts by weight of pentaerythritol, and 25 to 300 parts by weight of melamine. 3
The foamed refractory paint is characterized by comprising 00 parts by weight, 25 to 200 parts by weight of an inorganic powder, and 1 to 5 parts by weight of an inorganic fibrous substance. As described in JP-A-55-99915, for example, a one-pack modified epoxy resin is obtained by partially cross-linking a diglycidyl ether of bisphenol A with a linear saturated hydrocarbon-based or disubstituted benzene-based diamine. Used. In the present invention, bisphenol A
Instead of diglycidyl ether, bisphenol F, hydrogenated bisphenol A, β-methyl epichloro form, novolak form, resorcinol form, glycol ether form, etc.
Further, those obtained by modifying these with fatty acids can also be used. These one-component modified epoxy resins have a glass transition point of 5
When it is 0 to 120 ° C, particularly preferably 70 to 100 ° C
At the time, the effect of the present invention is exhibited. On the other hand, when the glass transition point is lower than 50 ° C., the coating tends to sag during a fire, and when it is higher than 120 ° C., cracks and the like tend to occur with time before the fire occurs. Ammonium polyphosphate and melamine are used as blowing agents. Ammonium polyphosphate is, for example, pyrophosphoric acid,
An ammonium salt of a condensate of orthophosphoric acid such as triphosphoric acid, trimetaphosphoric acid, and tetrametaphosphoric acid;
It is decomposed by heat of about 00 ° C. or more, and exhibits a fire extinguishing effect by generating nonflammable ammonia gas and desorbing H 2 O. As another blowing agent, dicyandiamide can be used in combination. Next, pentaerythritol is used as a carbon generating material. Pentaerythritol carbonizes by heat during the foaming of the foaming agent, and thus forms a porous carbonized layer containing bubbles therein. As other carbon generating materials, it is also possible to use in combination a material formed only of carbon, oxygen, and hydrogen, such as polyhydric alcohols other than pentaerythritol, polysaccharides, and expandable graphite. As inorganic powder, silicate,
Carbonate, aluminum oxide, clay, clay, shirasu, mica, titanium dioxide and the like can be used. As the inorganic fiber, asbestos, rock wool, glass fiber, silica alumina fiber, silicon carbide fiber and the like can be used. The composition ratio of these components is as follows: 100 parts by weight of the one-component modified epoxy resin in terms of solid content and 1 part of ammonium polyphosphate.
100 to 600 parts by weight, pentaerythritol 25 to 3
00 parts by weight, 25 to 300 parts by weight of melamine, 25 to 200 parts by weight of the inorganic powder, 1 to 5 parts by weight of the inorganic fibrous substance, and the inorganic fibrous substance is 0.1% of the total solid content of the refractory paint. It is preferably about 0.7% by weight. When the ratio is out of this range, the foamability of the coating film at the time of the occurrence of a fire is not uniform, or the adhesion and other physical properties of the coating film before the occurrence of the fire become insufficient. For example, if ammonium polyphosphate is 1
When the amount is less than 00 parts by weight, the expansion ratio is low, and the size of the bubbles becomes coarse. In addition, a cavity is formed in the foam layer, and the adhesion to the iron plate is reduced. On the other hand, when the amount of ammonium polyphosphate is more than 600 parts by weight, not only the foaming ratio is low, the size of the cells becomes coarse, but also the foamed layer itself sags over time, and the workability is reduced. Similarly, when the amount of pentaerythritol is less than 25 parts by weight, the expansion ratio is low and the size of the cells becomes coarse, so that the fire resistance is poor. In addition, a cavity is formed in the foam layer, and the adhesion to the iron plate is reduced. When the amount of pentaerythritol is more than 300 parts by weight, the expansion ratio is further lowered, and not only the size of the bubbles becomes coarse, but also the foamed layer itself drips over time,
Workability also decreases. Further, when the amount of melamine is 25 parts by weight or less or 300 parts by weight or more, the foam layer is not sagged, but the bubbles are coarse, and the adhesion to the iron plate and the workability are deteriorated. If the amount of the inorganic powder is less than 25 parts by weight, the number of projections on the surface increases, and the foamed layer is peeled off. 200
If the amount is more than the weight part, the workability is reduced and the size of the bubbles is not uniform, which leads to a reduction in fire resistance. When the amount of the inorganic fibrous substance is less than 1 part by weight, peeling of the foamed layer and sagging of the foamed layer occur. If the amount is more than 5 parts by weight, workability is reduced and cavities are generated at the interface with the base material.

[0005]

Although the detailed reaction mechanism of the foamable refractory paint of the present invention is not clearly understood, the balance between foaming and the strength of the carbonized layer is due to the use of a resin of a specific type and specific physical properties and the combined effect with various fillers. It is considered that the improvement in fire resistance and the elimination of protrusions due to sagging and uneven foaming became possible. In addition, it is considered that since the bubbles are uniformly dispersed in an appropriate size, the heat insulating effect is also increased.

[0006]

(Example 1) A hot-rolled steel plate (300 × 300
× 9 mm) as a base material, and a refractory foam paint having the composition shown in Table 1 was applied to the base material with a trowel to a thickness of 2 mm, and after curing for two weeks or more, a test piece was prepared. Test method Based on the standard curve specified in JIS A 1304,
For one hour, one side of the test piece was heated and heated in an electric furnace, and the elapsed time when the backside temperature of the hot-rolled steel sheet reached 350 ° C. was defined as fire resistance (time). , And other performance evaluations.・ Evaluation method Foaming magnification, fire resistance (time), bubble size (bubble uniformity), foam layer dripping (foam layer displacement), surface protrusion,
Adhesion to iron plate, presence or absence of cavities (occurrence at interface with substrate),
The peeling of the foam layer and the workability were evaluated according to the criteria shown in Table 2. Table 3 shows the results of the evaluation.
(Example 2, Comparative Examples 1 to 5) The same procedure as in Example 1 was carried out except that the composition shown in Table 1 was used.

[Table 1]

[Table 2]

[Table 3]

[0007]

The foamable refractory paint of the present invention has excellent adhesion to the underlying iron plate, foams by forming uniform air bubbles, and does not form protrusions due to dripping of the foam layer or uneven foaming on the surface. Fire resistance can be maintained.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-54-113630 (JP, A) JP-A-61-163973 (JP, A) JP-A-59-11377 (JP, A) JP-A-60-160 55079 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C09D 5/18 C09D 163/00-163/10

Claims (2)

(57) [Claims] 1. A one-component modified epoxy resin as a binder, ammonium polyphosphate and melamine as a foaming agent, pentaerythritol, an inorganic powder, and an inorganic fibrous substance as a carbon-forming material. 100 to 600 parts by weight of ammonium polyphosphate, 25 to 300 parts by weight of pentaerythritol, 25 to 300 parts by weight of melamine, 25 to 200 parts by weight of inorganic powder, 1 to 5 parts by weight of inorganic powder based on parts by weight. A foamed fire-resistant paint characterized by being in parts by weight. 2. The one-component modified epoxy resin has a glass transition point of 5
The foamed refractory paint according to claim 1, wherein the temperature is 0 to 120 ° C.