Fireproof paint and fireproof material wood

Abstract

To provide a fireproof paint capable of recognizing wood grain and utilizing unique look of wood grains, when coated on wood.SOLUTION: A fireproof paint in the embodiment contains, in terms of non-volatile content, 20-40 mass% of synthetic resin binder, 35-55 mass% of foaming agent, 10-30 mass% of carbonizing agent, and 1-10 mass% of foaming layer stabilizer. The foaming agent is a nitrogen compound-containing foaming agent, with an average particle diameter (median diameter; d50) of 5-20 μm. The fireproof paint can form a foaming layer due to a temperature rise during a fire, thanks to the balance of the contents of the synthetic resin binder, foaming agent, carbonizing agent, and foaming layer stabilizer. Furthermore, since the foaming agent is a nitrogen compound-containing foaming agent with an average particle diameter of 5-20 μm, a fireproof film formed when the fireproof paint is applied to wood has a low hiding power. Therefore, when applied to the wood, the wood grain is visible, which allows the unique appearance of the wood grain to be utilized.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a fireproof paint for making wood into a fireproof material, and a fireproof material wood made into a fireproof material by the fireproof paint.

Background Art

[0002] Conventionally, wood has been used as an industrial material such as building materials and furniture because it is flexible, lightweight, and the wood grain of the wood has a unique appearance. When wood is used as a building material in a building, depending on the type, scale, and region of the building, the use of fireproofed wood may be obligatory.

[0003] As a fireproof paint for making wood into a fireproof material, Patent Document 1 describes a fireproof paint containing a binder, a phosphorus compound, a foaming agent, a carbonizing agent, and a foaming layer stabilizer.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When wood is made into a fireproof material using a conventional fireproof paint, there is a problem that the wood grain may not be visible and the unique appearance of the wood grain may be lost because of the concealment of the raw materials contained in the fireproof paint in the fireproofed wood.

[0006] The present invention has been made in view of the above points, and an object thereof is to provide a fireproof paint that allows the wood grain to be visible and makes it possible to utilize the unique appearance of the wood grain when applied to wood.

Means for Solving the Problems

[0007] The fireproof paint of the embodiment is a fireproof paint containing a synthetic resin binder, a foaming agent, a charring agent, a foamed layer stabilizer, and a diluent, In terms of non-volatile content conversion, the synthetic resin binder is contained in an amount of 20 to 40% by mass, the foaming agent is contained in an amount of 35 to 55% by mass, the charring agent is contained in an amount of 10 to 30% by mass, and the foamed layer stabilizer is contained in an amount of 1 to 10% by mass. The foaming agent is a nitrogen compound-containing foaming agent, and is characterized in that the average particle diameter (median diameter; d50) is 5 to 20 μm.

[0008] According to the fireproof paint of the embodiment, due to the content balance of the synthetic resin binder, the foaming agent, the charring agent, and the foamed layer stabilizer, the fireproof coating film formed from the fireproof paint forms a foamed layer due to the temperature rise during a fire and can exhibit fireproof performance. Further, since the foaming agent is a nitrogen compound-containing foaming agent and the average particle diameter (median diameter; d50) is 5 to 20 μm, the fireproof coating film formed from the fireproof paint has a low hiding power. Therefore, when the fireproof paint of the embodiment is applied to wood, the wood grain can be visually recognized and the unique appearance of the wood grain can be utilized.

[0009] Here, in the above fireproof paint, the foaming agent can be ammonium polyphosphate.

[0010] According to this, a foamed layer can be formed due to the temperature rise during a fire, and the fireproof coating film formed by applying the fireproof paint to wood can have a low hiding power, and when applied to wood, the wood grain can be visually recognized and the unique appearance of the wood grain can be utilized.

[0011] Also, in the above fireproof paint, the foamed layer stabilizer can be fumed silica.

[0012] According to this, the foamed layer foamed due to the temperature rise during a fire can be stabilized, and the fireproof coating film formed by applying the fireproof paint to wood can have a low hiding power, and when applied to wood, the wood grain can be visually recognized and the unique appearance of the wood grain can be utilized.

[0013] Here, the fireproof material wood made into a fireproof material by a fireproof paint includes the base wood, a primer coating film formed on the surface of the wood and formed from a primer paint, and a fireproof coating film formed on the upper side of the primer coating film and formed from the fireproof paint.

[0014] According to this, the adhesion of the fireproof coating film to the wood can be enhanced by the primer coating film. Since the fireproof coating film has a low hiding power, the wood grain of the base material can be visually recognized, and the unique appearance of the wood grain can be utilized. A foamed layer can be formed by the temperature rise during a fire to exhibit fireproof performance.

[0015] Also, the fireproof material wood can be provided with a topcoat film formed on the upper side of the fireproof coating film and formed from a topcoat paint.

[0016] According to this, the water resistance of the fireproof coating film can be enhanced.

[0017] Also, the fireproof material wood can be such that the primer paint contains a synthetic resin binder and polysiloxane.

[0018] According to this, the adhesion of the fireproof coating film to the wood can be enhanced.

[0019] Also, the fireproof material wood can be such that the topcoat paint contains a synthetic resin binder and an ultraviolet reflective pigment.

[0020] According to this, the weather resistance of the fireproof coating film can be enhanced.

Advantages of the Invention

[0021] According to the fireproof paint of the embodiment, fireproof performance can be exhibited, and when applied to wood, the wood grain can be visually recognized, and the unique appearance of the wood grain can be utilized.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Mode for Carrying Out the Invention

[0023] Hereinafter, a fireproof material according to an embodiment and fireproof material wood made into a fireproof material by a fireproof paint will be described. The fireproof paint is applied to wood 1 as a base material to form a film, thereby making the base material a non-combustible material, a semi-non-combustible material, or a flame-retardant material as a fireproof material under the Building Standards Act. Fireproof material wood is wood 1 that satisfies the requirements of a fireproof material by applying a fireproof paint to form a fireproof coating 20.

[0024] The fireproof paint of the embodiment contains a synthetic resin binder, a foaming agent, a carbonizing agent, a foaming layer stabilizer, and a diluent. In terms of non-volatile content conversion, the fireproof paint contains 20 to 40% by mass of the synthetic resin binder, 35 to 55% by mass of the foaming agent, 10 to 30% by mass of the carbonizing agent, and 1 to 10% by mass of the foaming layer stabilizer, and the foaming agent is a nitrogen compound-containing foaming agent having an average particle diameter (median diameter; d50) of 5 to 20 μm. Further, as shown in FIG. 1, the fireproof material wood of the embodiment includes an undercoat film 30 formed from an undercoat paint on the surface of the wood 1 serving as a base material, and a fireproof coating 20 formed from the fireproof paint of the embodiment above the undercoat film. An overcoat film 40 formed from an overcoat paint can be provided above the fireproof coating 20. Note that the upper (upper side) in the fireproof material wood (wood 1) means the outside from the wood 1.

[0025] The synthetic resin binder is a synthetic resin that holds foaming agents, carbonizing agents, foaming layer stabilizers, etc. contained in the fireproof paint and serves as the binder of the fireproof coating 20. Depending on the composition of the synthetic resin binder (the types of monomers used), the performance of the coating formed from the fireproof paint varies greatly. As the composition of the synthetic resin binder, for example, vinyl acetate resin, ethylene vinyl acetate resin, acrylic resin, polyester resin, polyurethane resin, alkyd resin, styrene resin, etc. can be used. These resins include modified resins such as urethane-modified resin, silicone-modified resin, fluorine-modified resin, or epoxy-modified resin. Among these, alkyd resin and acrylic resin, which have excellent adhesion to the wood 1 or the undercoat film 30, can be preferably used, and acrylic resin, which is excellent in light resistance in addition to adhesion, can be more preferably used. In addition, the alkyd resin and the acrylic resin can be made to have even better adhesion to the wood by being made into urethane-modified resins.

[0026] The synthetic resin binder is dispersed in a solvent to have the fluidity required as a paint. The synthetic resin binder includes a resin emulsion with water as the main solvent and an organic solvent-soluble resin with an organic solvent as the main solvent. The fireproof paint using the resin emulsion as the binder becomes an aqueous fireproof paint. In the aqueous fireproof paint, as the solvent such as water volatilizes, the resin fine particles fuse with each other to form a resin film, and a coating film is formed. The fireproof paint using the organic solvent-soluble resin as the binder becomes an organic solvent-based fireproof paint. In the organic solvent-based fireproof paint, as the organic solvent as the medium volatilizes, the chain-like resin penetrates into the wood 1 or the undercoat film 30 while a coating film is formed. The synthetic resin binder can be used as the binder of the fireproof paint in the embodiment regardless of whether it is a resin emulsion or an organic solvent-soluble resin. However, since the organic solvent-soluble resin easily penetrates into the wood 1 or the undercoat film 30 and has excellent adhesion, it can be more preferably used.

[0027] The average molecular weight of the synthetic resin binder can be set to 20,000 to 50,000. This is because the fireproof coating film 20 formed from the fireproof paint can have an elongation rate that can follow the expansion or expansion and contraction due to temperature changes of the wood 1, and the workability of applying the fireproof paint can also be excellent. When the average molecular weight of the synthetic resin binder is less than 20,000, it is difficult for the chain-like synthetic resin binder to have a structure that is easy to stretch, and the elongation rate of the fireproof coating film 20 formed from the fireproof paint may not be satisfied. On the other hand, when the average molecular weight of the resin exceeds 50,000, although the elongation rate of the fireproof coating film 20 formed from the fireproof paint is satisfied, the length of the chain-like synthetic resin binder becomes long and lacks fluidity, and the workability of applying the fireproof paint may be inferior. As another embodiment, the average molecular weight of the synthetic resin binder can be set to 30,000 to 40,000.

[0028] The glass transition temperature (Tg) of the synthetic resin binder can be set to -30 to 10 °C. This is because the fireproof coating film 20 formed from the fireproof paint has flexibility that can follow the expansion and contraction of the wood, and due to the appropriate flexibility, the adhesion of dirt to the coating film is small and the appearance of the coating film is maintained. When the Tg of the synthetic resin binder is below -30 °C, although the elongation rate of the fireproof coating film 20 formed from the fireproof paint is satisfied (25% or more), the binder of the fireproof coating film 20 becomes soft, and foreign substances such as dust are likely to adhere, and the appearance of the fireproof coating film 20 may not be maintained. On the other hand, when Tg exceeds 10 °C, the binder of the fireproof coating film 20 becomes hard, and the elongation rate of the fireproof coating film 20 may not be satisfied (less than 25%). As another embodiment, the Tg of the synthetic resin binder can be set to -20 to 5 °C, and as yet another embodiment, Tg can be set to -15 to 0 °C. The adjustment of Tg can be performed by adjusting the type and amount of the monomer used. Tg can be obtained from the calculation formula of Fox (the following formula (1)). Here, Wi represents the mass fraction of monomer i, and Tgi represents the Tg (°C) of monomer i. As the Tg of the monomer, known values such as those described in the Polymer Handbook (John Wiley & Sons) can be used.

[0029] (Formula 1) 1 / (273 + Tg) = Σ(Wi / (273 + Tgi)) ··· (1) The synthetic resin binder can be synthesized by using a general polymerization method. The combination of monomers can be selected according to the resin composition and the set Tg. The average molecular weight can be adjusted by changing the polymerization conditions such as the temperature and time during polymerization. In addition, commercially available synthetic resin binders can also be used. As commercially available organic solvent-soluble resins, the Harifutar series (Harima Kasei Group Co., Ltd.), the Kodouble series (Nippon Shokubai Co., Ltd.), the Alkydia series (DIC Corporation), the Arakido series (Arakawa Chemical Industries, Ltd.), etc. can be used. As commercially available resin emulsions, the Acronal series (BASF Japan Ltd.), the Polytoron series (Asahi Kasei Chemicals Corporation), the AE series (E-Tech Co., Ltd.), etc. can be used.

[0030] The content rate (in terms of non-volatile matter) of the synthetic resin binder in the fireproof paint can be 20 to 40% by mass. This is because the fireproof coating 20 formed from the fireproof paint can exhibit fireproof performance and can have flexibility to follow the expansion and contraction of wood. When the content rate of the synthetic resin binder in the fireproof paint is less than 20% by mass, the flexibility (elongation rate) of the fireproof coating 20 formed from the fireproof paint may not be satisfied. On the other hand, when the content rate of the synthetic resin binder in the fireproof paint exceeds 40% by mass, the content rate of the synthetic resin binder, which is a combustible component, is high, and there is a possibility that the fireproof performance of the fireproof coating 20 formed from the fireproof paint cannot be exhibited. As another embodiment, the content rate of the synthetic resin binder in the fireproof paint can be 25 to 35% by mass.

[0031] The foaming agent is an additive that causes the fireproof coating 20 containing a foaming agent, a synthetic resin binder, a carbonizing agent, and a foamed layer stabilizer to foam and form a foamed layer when the fireproof coating 20 is heated. As the foaming agent, a nitrogen compound-containing foaming agent that can generate a large amount of nitrogen gas, ammonia gas, etc. when heated can be used. As the nitrogen compound-containing foaming agent, ammonium polyphosphate, ammonium phosphate, melamine phosphate, melamine, dicyandiamide, azodicarbonimide, urea, ammonium polyacrylate, ammonium acrylate, etc. can be used. As another embodiment, ammonium polyphosphate, ammonium phosphate, and melamine phosphate, which are excellent in the foamability of the fireproof coating 20, can be used. As yet another embodiment, ammonium polyphosphate can be used.

[0032] The average particle diameter (median diameter; d50) of the nitrogen compound-containing foaming agent can be 5 to 20 μm. The fireproof coating 20 formed from a fireproof paint containing a nitrogen compound-containing foaming agent with an average particle diameter of 5 to 20 μm can have a low hiding power (JIS K 5600-4-1:1999, film applicator: 100 μm) (20% or less). The wood covered with the fireproof coating 20 can have its grain visually recognized and can utilize the unique appearance of the grain. When the average particle diameter of the nitrogen compound-containing foaming agent is less than 5 μm, at the addition amount that can exhibit the function as a foaming agent, there are many fine particles, which may increase the viscosity of the fireproof paint and deteriorate the coating workability. On the other hand, when the average particle diameter exceeds 20 μm, the hiding power of the fireproof coating 20 formed from the fireproof paint may increase, and there is a possibility that the grain of the wood cannot be visually recognized. As another embodiment, the average particle diameter of the nitrogen compound-containing foaming agent can be 10 to 15 μm.

[0033] Ammonium polyphosphate is a nitrogen compound-containing foaming agent represented by the following chemical formula (1). (Chemical formula 1) NH4O(NH4PO3) n NH4(1) (In the formula, n is the degree of polymerization.) When the nitrogen compound-containing blowing agent is ammonium polyphosphate, the average degree of polymerization of ammonium polyphosphate can be 5 to 500 (phosphorus content: 29 to 32% by mass). This is because nitrogen gas and ammonia gas can be stably generated when heated. When the average degree of polymerization of ammonium polyphosphate is less than 5, ammonium polyphosphate has poor stability and may decompose. As another embodiment, the average degree of polymerization of ammonium polyphosphate can be 10 to 100 (phosphorus content: 30 to 32% by mass), and as yet another embodiment, it can be 20 to 50 (phosphorus content: 31 to 32% by mass). Note that ammonium polyphosphate forms particles with an average particle diameter of 5 to 20 μm by the aggregation of a large number of polymers.

[0034] The content of the blowing agent in the fireproof paint can be 35 to 55% by mass. This is because when the fireproof coating 20 formed from the fireproof paint is heated, nitrogen gas and ammonia gas can be stably generated, and a foamed layer can be formed due to the temperature rise during a fire. When the content of the blowing agent in the fireproof paint is less than 35% by mass, the generated nitrogen gas and ammonia gas are less, and a sufficient foamed layer cannot be formed due to the temperature rise during a fire, and there is a risk of inferior non-combustibility (heat generation). On the other hand, when it exceeds 55% by mass, the synthetic resin binder for forming the foamed layer becomes relatively less, and there is also a risk that a sufficient foamed layer cannot be formed. As another embodiment, the content of the blowing agent in the fireproof paint can be 40 to 50% by mass.

[0035] The charring agent is considered to react (dehydration carbonization) with the nitrogen compound-containing blowing agent to form a carbonized layer when the fireproof coating 20 formed from the fireproof paint forms a foamed layer due to the temperature rise during a fire, thereby enhancing the heat insulation of the foamed layer. As the charring agent, polyhydric alcohols such as pentaerythritol, dipentaerythritol, tripentaerythritol, polypentaerythritol, polyvinyl alcohol, starch, casein, etc. can be used.

[0036] The carbonizing agent content in the fireproof coating can be 10 to 30% by mass. This is because when the fireproof coating 20 formed from the fireproof coating is heated, a carbonized layer is formed, which can enhance the heat insulation property of the foamed layer. If the carbonizing agent content in the fireproof coating is less than 10% by mass, a sufficient carbonized layer may not be formed, and there is a risk that the heat insulation property of the foamed layer cannot be sufficiently enhanced. On the other hand, when the carbonizing agent content exceeds 30% by mass, unreacted carbonizing agent may occur due to the mixing balance of the raw materials, resulting in insufficient formation of the carbonized layer and a risk that the heat insulation property of the foamed layer cannot be enhanced. As another embodiment, the carbonizing agent content in the fireproof coating can be 15 to 25% by mass.

[0037] The foamed layer stabilizer is an additive that stabilizes the foamed layer formed by the fireproof coating 20 formed from the fireproof coating due to the temperature rise during a fire. As the foamed layer stabilizer, metal oxides, particularly silica powder and alumina powder, can be used. As another embodiment, fumed silica and fumed alumina can be used, and as yet another embodiment, fumed silica can be used. By using fumed silica as the foamed layer stabilizer, the foamed layer foamed by the temperature rise can be stabilized, and the structural viscosity of fumed silica can prevent the sedimentation and separation of the raw materials in the state of the fireproof coating.

[0038] The average particle diameter (median diameter; d50) of the foamed layer stabilizer can be 5 to 50 nm. This is because the foamed layer foamed by the temperature rise during a fire can be stabilized. If the average particle diameter of the foamed layer stabilizer is less than 5 nm, there is a risk that the foamed layer cannot be sufficiently stabilized. On the other hand, when the average particle diameter exceeds 50 nm, the surface area of the foamed layer stabilizer becomes small, and there is a risk that the foamed layer cannot be sufficiently stabilized. As another embodiment, the average particle diameter of the foamed layer stabilizer can be 7 to 30 nm, and as yet another embodiment, it can be 10 to 20 nm.

[0039] The content rate of the foaming layer stabilizer in the fireproof coating can be 1 to 10% by mass. This is because it can stabilize the foaming layer foamed by the temperature rise during a fire. When the content rate of the foaming layer stabilizer in the fireproof coating is less than 1% by mass, there is a possibility that the foamed foaming layer cannot be sufficiently stabilized. On the other hand, when the content rate of the foaming layer stabilizer exceeds 10% by mass, due to the blending balance of the raw materials, unreacted foaming layer stabilizer may be generated, resulting in insufficient formation of the carbonized layer and a possibility that the heat insulation property of the foaming layer cannot be enhanced. As another embodiment, the content rate of the foaming layer stabilizer in the fireproof coating can be 1.5 to 8% by mass, and as yet another embodiment, it can be 2 to 5% by mass.

[0040] As the diluent, a diluent dispersible in the synthetic resin binder can be used. As the diluent of the organic solvent, alkyl acetates, glycol acetates, glycol monoether acetates, etc. can be used. As the alkyl acetates, butyl acetate etc. can be used. As the glycol acetates, diethylene glycol monoacetate, ethylene glycol diacetate, propylene glycol diacetate, glycerin diacetate, glycerin triacetate, etc. can be used. As the glycol monoether acetates, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, dipropylene glycol monomethyl ether acetate, 3-methoxybutyl acetate, 3-methoxy-3-methyl-1-butyl acetate, etc. can be used.

[0041] For fireproof coatings, as other additives, additives commonly added to general coatings such as viscosity modifiers, defoamers, ultraviolet absorbers, anti-algae and anti-mold agents, pigments, fillers, and matting agents can be added.

[0042] Fireproof coatings can be manufactured by uniformly stirring a synthetic resin binder, a foaming agent, a carbonizing agent, a foaming layer stabilizer, a diluent, and other additives using a stirrer such as a general-purpose mixer or dissolver.

[0043] The wood 1 to which the fireproof coating is applied can be used for both hardwoods and softwoods, and its type is not particularly limited. As another embodiment, it can be a softwood commonly used in building materials. As yet another embodiment, it can be Japanese red pine, Japanese black pine, sugi, or hinoki, which are said to have beautiful grain.

[0044] Next, a method for applying the fireproof coating to the wood 1 will be described. The application of the fireproof coating to the wood 1 includes a surface treatment step of leveling the surface of the wood 1, a primer coating step of applying a primer coating to form a primer film 30, which is performed after the surface treatment step, a middle coating step of applying the fireproof coating according to the embodiment to form a fireproof film, which is performed after the primer coating step, and a top coating step of applying a top coating to form a top coating film 40, which is performed after the middle coating step. Note that depending on the type of the wood 1, the primer coating step can be omitted, and depending on the part where the wood 1 is arranged as a building material, the top coating step can also be omitted.

[0045] The surface treatment step is performed to remove the fuzz on the surface of the wood 1 and level the surface, and it is performed by polishing using sandpaper. Sandpaper with a medium grit of #120 to #240 can be used.

[0046] The primer coating step is a step of applying a primer coating using a general-purpose coating tool such as a spray, roller, or brush. As the primer coating, general-purpose products for wood primers can be used, and an example of the primer coating formulation is shown in Table 1. The raw material blending amount is the blending amount in terms of non-volatile content excluding the diluent.

[0047]

Table 1

[0048] The intermediate coating process is a process of applying any of the fireproof paints described in Tables 3 to 5 below using a general-purpose painting tool such as a spray, roller, or brush on the primer coating 30 formed on the surface of the wood 1. The fireproof paint can form a foamed layer due to the temperature rise during a fire depending on the content balance of the synthetic resin binder, foaming agent, charring agent, and foamed layer stabilizer. Further, the foaming agent is a nitrogen compound-containing foaming agent, and since the average particle diameter (median diameter; d50) is 5 to 20 μm, the fireproof coating formed by applying the fireproof paint to the wood has a low hiding power. Therefore, when the fireproof paint of the embodiment is applied to the wood, the wood grain can be visually recognized, and the unique appearance of the wood grain can be utilized.

[0049] The coating amount of the fireproof paint varies depending on the required fireproof performance. In the fireproof paints of Test Examples 1 to 3 in Table 3 described below, when it is a non-combustible material, it is 1000 to 1200 g / m 2 (in terms of non-volatile content conversion: 735 to 880 g / m 2 ), when it is a semi-non-combustible material, it is 800 to 1000 g / m 2 (in terms of non-volatile content conversion: 590 to 735 g / m 2 ), and when it is a flame-retardant material, it is 600 to 800 g / m 2 (in terms of non-volatile content conversion: 440 to 590 g / m 2 ). Note that the fireproof paint can be applied in two coats to prevent cracking due to paint shrinkage.

[0050] The top coating process is a process of applying a top coating paint using a general-purpose painting tool such as a spray, roller, or brush on the fireproof coating 20 formed on the surface of the wood 1. As the top coating paint, a top coating paint for wood or a general-purpose product of the top coating paint can be used. Further, as the top coating paint for wood, the wood paint described in Japanese Patent Application Laid-Open No. 2019-108461 filed by the applicant of the present application can also be used. An example of the top coating paint formulation is described in Table 2. The raw material formulation amounts are the formulation amounts in terms of non-volatile content excluding the diluent.

[0051]

Table 2

Example

[0052] The raw material compounding amounts (mass %) and test results (heat generation test and hiding power) of the fireproof paint for wood of the embodiment are described in Tables 3 to 5. The raw material compounding amounts are the compounding amounts in terms of non-volatile content excluding the diluent. The details of the raw materials are described below.

[0053] Synthetic resin binder A Composition: Acrylic resin Average molecular weight: 35,000 Non-volatile content: 50 mass % Dispersion medium: Butyl acetate Tg: -10°C Synthetic resin binder B Composition: Urethane-modified acrylic resin Average molecular weight: 32,000 Non-volatile content: 50 mass% Dispersion medium: Butyl acetate Tg: -5°C Blowing agent A Composition: Ammonium polyphosphate Average degree of polymerization: Approximately 100 Average particle diameter: 8 μm Blowing agent B Composition: Ammonium polyphosphate Average degree of polymerization: Approximately 100 Average particle diameter: 15 μm Blowing agent C Composition: Ammonium polyphosphate Average degree of polymerization: Approximately 100 Average particle diameter: 25 μm Blowing agent D Composition: Melamine phosphate Average particle diameter: 15 μm Charring agent Composition: Dipentaerythritol Foam layer stabilizer Type: Fumed silica Average particle diameter: 12 nm Organic solvent Composition: Butyl acetate Commercially available products were used for these raw materials.

[0054] For the fire-retardant paint for wood in the test example, specimens (fireproof material wood) were prepared and evaluated by a heat release test and an accelerated weather resistance test for hiding power promotion. The conditions and evaluation methods of the accelerated weather resistance test are described below.

[0055] <Heat release test> The heat release test was conducted using a cone calorimeter (conforming to ISO 5660-1:2002). Then, those that met the following performance requirements with a heating time of 20 minutes (non-combustible materials) were rated as ◎, those that met the following performance requirements with a heating time of 10 minutes (semi-non-combustible materials) were rated as ○, those that met the following performance requirements with a heating time of 5 minutes (flame-retardant materials) were rated as △, and those that did not meet the following performance requirements without waiting for 5 minutes of heating time were rated as ×. Performance requirement details: (1) Total heat release 8 MJ / m 2 Subsequently, (2) the maximum heat release rate does not exceed 200 kW / m continuously for more than 10 seconds 2 and (3) there are no cracks and holes penetrating to the fire-hazardous back surface, and all of these must be satisfied.

[0056] <Hiding power> The hiding power was measured according to the following standard. Standard: General test methods for paints - Part 4: Visual properties of paint films - Section 1: Hiding power (for light-colored paints) (JIS K 5600-4-1:1999), and a film applicator of 100 μm was used. Then, those with a hiding power of 10% or less where the grain of Wood 1 was easily visible through were rated as ◎, those with a hiding power exceeding 10% and less than or equal to 15% were rated as ○, those with a hiding power exceeding 15% and less than or equal to 20% were rated as △, and those exceeding 20% were rated as ×.

[0057] Test examples 1 to 4, 6 to 8, and 11 to 13 were examples, and test examples 5, 9, 10, and 14 were comparative examples.

[0058]

Table 3

[0059] For test examples 1 to 4, a surface treatment process was performed on a 30-mm-thick Japanese cedar board (Wood 1) using #180 sandpaper, and the undercoat paint described in Table 1 was applied at 50 g / m2 The primer coating process was carried out with the coating amount (Wet) of 2 The intermediate coating process was carried out with the coating amount (Wet) of 2 The top coating process was carried out with the coating amount (Wet) of

[0060] In Test Example 1, a fireproof paint using blowing agent A, which is ammonium polyphosphate with an average particle diameter of 8 μm and an average degree of polymerization of about 100, was used as the blowing agent for the fireproof paint. In Test Example 1, the exothermic test satisfied the performance requirement content for a heating time of 20 minutes (◎), and the hiding power was 10% or less (◎).

[0061] In Test Example 2, a fireproof paint using blowing agent B, which is ammonium polyphosphate with an average particle diameter of 15 μm and an average degree of polymerization of about 100, was used as the blowing agent for the fireproof paint. In Test Example 2, the exothermic test satisfied the performance requirement content for a heating time of 20 minutes (◎), and the hiding power was 10% or less (◎). A photograph of the test specimen of Test Example 2 (fireproof material wood (however, the top coating process is omitted)) is shown in Figure 2.

[0062] In Test Example 3, a fireproof paint using blowing agent C, which is ammonium polyphosphate with an average particle diameter of 25 μm and an average degree of polymerization of about 100, was used as the blowing agent for the fireproof paint. In Test Example 3, the exothermic test satisfied the performance requirement content for a heating time of 20 minutes (◎), and the hiding power exceeded 15% and was 20% or less (△). A photograph of the test specimen of Test Example 3 (fireproof material wood (however, the top coating process is omitted)) is shown in Figure 2.

[0063] In Test Example 4, a fireproof paint using blowing agent D, which is melamine phosphate with an average particle diameter of 15 μm and an average degree of polymerization of about 100, was used as the blowing agent for the fireproof paint. In Test Example 4, the exothermic test satisfied the performance requirement content for a heating time of 10 minutes (○), and the hiding power exceeded 10% and was 15% or less (○).

[0064]

Table 4

[0065] In Test Examples 5 to 9, a surface treatment process was performed on a 40-mm-thick Japanese cypress board (Wood 1) using #180 sandpaper, and the fireproof paints of Test Examples 5 to 9 were each applied in a coating amount (Wet) of 1000 g / m 2 in an intermediate coating process, and the topcoat paint described in Table 2 was applied in a coating amount (Wet) of 50 g / m 2 in a topcoat process to obtain test specimens. Note that the primer process is omitted.

[0066] Test Example 5 used a fireproof paint containing 15% by mass of the synthetic resin binder B. In Test Example 5, the balance of the contents of the synthetic resin binder, the foaming agent, the charring agent, and the foam layer stabilizer was not good, and the heat generation test did not meet the performance requirement content without waiting for 5 minutes of heating time (×). Also, relatively, the content of the foaming agent B increased, and the hiding power exceeded 20% (×). A photograph of the test specimen of Test Example 5 (fireproof material wood (however, the topcoat process is omitted)) is shown in Figure 2.

[0067] Test Example 6 used a fireproof paint containing 20% by mass of the synthetic resin binder B. In Test Example 6, the heat generation test met the performance requirement content for 10 minutes of heating time (○), and the hiding power exceeded 15% and was 20% or less (△).

[0068] Test Example 7 used a fireproof paint containing 30% by mass of the synthetic resin binder B. In Test Example 7, the heat generation test met the performance requirement content for 20 minutes of heating time (◎), and the hiding power was 10% or less (◎).

[0069] Test Example 8 uses a fireproof paint containing 40% by mass of synthetic resin binder B. In Test Example 8, the exothermic test satisfied the performance requirement content for a heating time of 10 minutes (○), and the hiding power was 10% or less (◎).

[0070] Test Example 9 uses a fireproof paint containing 50% by mass of synthetic resin binder B. In Test Example 9, the balance of the contents of the synthetic resin binder, foaming agent, charring agent, and foaming layer stabilizer was not good, and the exothermic test did not satisfy the performance requirement content without waiting for 5 minutes of heating time (×). The hiding power was 10% or less (◎) because the content of the foaming agent was relatively reduced.

[0071]

Table 5

[0072] In Test Examples 10 - 14, a surface treatment process was performed on a 40 - mm - thick cypress board (Wood 1) using #180 sandpaper, and the undercoat paint described in Table 1 was applied in an application amount (Wet) of 50 g / m 2 for the undercoat process. The fireproof paints of Test Examples 5 - 9 were each applied in an application amount (Wet) of 1000 g / m 2 for the intermediate coat process to obtain test specimens. Note that the topcoat process was omitted.

[0073] Test Example 10 used a fireproof paint containing 30% by mass of blowing agent B. In Test Example 10, the balance of the contents of the synthetic resin binder, blowing agent, charring agent, and foamed layer stabilizer was not good, and the heat generation test did not meet the performance requirements without waiting for 5 minutes of heating time (×). Since the content of the blowing agent was small, the hiding power was 10% or less (◎).

[0074] Test Example 11 used a fireproof paint containing 35% by mass of blowing agent B. In Test Example 11, the heat generation test met the performance requirements for 10 minutes of heating time (○), and the hiding power was 10% or less (◎).

[0075] Test Example 12 used a fireproof paint containing 40% by mass of blowing agent B. In Test Example 12, the heat generation test met the performance requirements for 20 minutes of heating time (◎), and the hiding power was 10% or less (◎).

[0076] Test Example 13 used a fireproof paint containing 55% by mass of blowing agent B. In Test Example 13, the heat generation test met the performance requirements for 5 minutes of heating time (△), and the hiding power exceeded 15% and was 20% or less (△).

[0077] Test Example 14 used a fireproof paint containing 60% by mass of blowing agent B. In Test Example 14, the balance of the contents of the synthetic resin binder, blowing agent, charring agent, and foamed layer stabilizer was not good, and the heat generation test did not meet the performance requirements without waiting for 5 minutes of heating time (×). Also, since the content of blowing agent B was large, the hiding power exceeded 20% (×).

Explanation of Symbols

[0078] 1…Wood, 20…Fireproof coating, 30…Undercoat, 40…Topcoat.

Claims

1. A fireproof paint containing a synthetic resin binder, a foaming agent, a carbonizing agent, a foaming layer stabilizer, and a diluent, In terms of non-volatile content, the synthetic resin binder is 20 to 40% by mass, the foaming agent is 35 to 55% by mass, the carbonizing agent is 10 to 30% by mass, and the foaming layer stabilizer is 1 to 10% by mass, The foaming agent is a nitrogen compound-containing foaming agent, and the average particle diameter (median diameter; d50) is 5 to 20 μm. The fireproof paint is characterized by this.

2. The fireproof paint according to claim 1, wherein the foaming agent is ammonium polyphosphate.

3. The fireproof paint according to claim 1, wherein the foaming layer stabilizer is fumed silica.

4. Wood as a base material, A primer coating film formed from a primer paint on the surface of the wood, and a fireproof coating film formed from the fireproof paint according to any one of claims 1 to 3 on the upper side of the primer coating film. The fireproof material wood is characterized by comprising these.

5. The fireproof material wood according to claim 4, further comprising a topcoat film formed from a topcoat paint on the upper side of the fireproof coating film.

6. The fireproof material wood according to claim 4, wherein the primer paint contains a synthetic resin binder and polysiloxane.

Images