JPH10266401A - Nonflammable construction material and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve chemical impregnation process efficiency by impregnating wood plates of two surface layers with a nonflammable chemical, forming a base plate with a laminated material connected with many wood units, and laminating three or more plates via an adhesive. SOLUTION: Three or more plates having low specific gravity and a good nonflammable chemical injecting property are laminated via an adhesive to form construction plywood. When this plywood is manufactured, at least two surface plates 1 are immersed in a nonflammable chemical tank heated to 50 deg.C or above to be impregnated with a chemical, or the surface plates 1 can be boiled by hot water and immersed in the nonflammable chemical tank at 30 deg.C or below. The surface plates 1 impregnated with the chemical are stuck to a plywood material 2 made of a laminated material connected with many wood units. This plywood is used as an interior material for a wall or a ceiling, and the fire protecting property is improved. A nonflammability process is efficiently applied in a short time, and the strength of the plate material can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant material for building which is made by laminating wooden plate materials via an adhesive, and a method for producing a flame-retardant material for building.

[0002]

2. Description of the Related Art Generally, there are restrictions on the interior of buildings such as walls and ceilings from the viewpoint of fire prevention by the Ordinance for Enforcement of the Building Standards Law. Department is defined. Wood is a burning material, especially in high-rise buildings and special buildings with large floor areas, such as viewing halls, public halls, hospitals, hotels, inns, apartments, department stores, restaurants, restaurants, etc. Use is greatly restricted. Therefore, in such a building, wood is subjected to a flame retarding treatment, and is used as a “flame retardant for construction”. Conventionally, as a flame retardant for this type of building, for example, using a vacuum press, a wooden plate is immersed in a flame-retardant chemical at room temperature, depressurized for a predetermined time, then pressurized for a predetermined time, Some are impregnated with flame retardant chemicals.

[0003]

In the conventional flame-retardant material for construction, however, the entire plate must be treated with a flame-retardant chemical, so that the treatment volume is large and the inside cannot be sufficiently impregnated. In addition, there is a problem that the flame retardancy is inferior, and there is also a problem that if sufficient impregnation is attempted, the impregnation process takes a long time and the treatment efficiency is poor. In order to solve this problem, it is conceivable to use a single thin surface plate, impregnate it sufficiently with a flame-retardant chemical, and adhere this surface plate to the base plate material. For that reason, the flame retardancy is inferior to that extent, and simply bonding the surface plate becomes insufficient.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has been made by improving the impregnating efficiency of a plate material and ensuring the flame retardancy of the front surface side, so that an architectural structure manufactured by stacking plate materials. It is an object of the present invention to provide a method for producing a flame retardant for construction and a flame retardant for construction.

[0005]

According to the present invention, there is provided a flame-retardant material for construction according to the present invention, in which three or more wooden boards are laminated via an adhesive and at least two layers on the front side. Is formed as a surface plate material impregnated with a flame-retardant chemical solution. In this case, it is effective to configure the back plate as a base plate that is not impregnated with the flame retardant chemical. And it is effective that the back side plate material is formed of a laminated material in which a large number of wood pieces are joined together via an adhesive.

[0006] In addition, a method for manufacturing a flame retardant material for construction according to the present invention for solving the above-mentioned problems is a method for manufacturing a flame retardant material for construction, which is manufactured by laminating three or more wooden plate materials via an adhesive. A manufacturing method, wherein a plate material forming at least two layers on the front side is provided.
It is configured to be impregnated with a flame-retardant chemical in advance, and then laminated and manufactured. If necessary, when impregnating with the above-mentioned flame-retardant chemical, the plate material is immersed in a flame-retardant chemical tank heated to 50 ° C. or higher. In addition, when impregnated with the above-mentioned flame-retardant chemical, if necessary, the plate is boiled in hot water and then immersed in a flame-retardant chemical tank at 30 ° C. or lower.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of a flame retardant material for a building according to an embodiment of the present invention. As shown in FIG. 1, the architectural flame retardant according to the embodiment of the present invention is configured by stacking three or more wooden plate members (three in the embodiment) with an adhesive 3 interposed therebetween. Two plate members forming the two layers on the front side are configured as surface plate members 1 and 1 impregnated with a flame-retardant chemical. One plate material on the back side is configured as a base material 2 that is not impregnated with a flame-retardant chemical, and the base material 2 is formed of a laminated material in which a large number of wood pieces are joined via an adhesive 4. . The architectural flame-retardant material according to the embodiment is an elongated plate member, and has ridges 5 and recesses 6 which can be connected to adjacent plate members and formed continuously at both end portions. Have been.

As a material of the surface plate material 1, for example, considering the added value as an interior material, a hardwood is used instead of a general softwood, a low specific gravity, and a flame-retardant chemical liquid injection property is excellent. , Sawagurumi, Sina etc. are used. The thickness per sheet is, for example, 4.0 mm ± 1.0 mm, weight 6.0 ± 2.0 kg / m ² (specific gravity 0.43 ± 0.0
Use 5). As a material of the base material 2, for example,
Use glued laminated wood such as Sawagurumi and China in the same manner as above.
The thickness is, for example, 7.0 mm ± 2.0 mm and the weight is 3.0.
A material having a density of ± 1.0 kg / m ² (specific gravity 0.43 ± 0.05) is used.

As the flame retardant chemical, for example, an appropriate one such as a phosphoric acid flame retardant (for example, a solid content of 203 kg / m ³ ) is used. Examples of the adhesive for the surface plate 1 include, for example,
Urea resin is used (for example, a coating amount of 23
5 ± 15 g / m ² ). Further, as an adhesive for the laminated material of the base material 2, for example, an aqueous vinyl urethane-based resin is used (for example, an application amount of 255 ± 25 g / m ² ).

Next, a method for manufacturing a flame-retardant material for construction according to an embodiment of the present invention will be described. As shown in FIG.
A surface plate 1 and a base plate 2 are prepared. Then, the surface plate 1 is preliminarily treated by a hot / cold bath method. This hot / cold bath method is a method in which a plate material is first boiled with hot water () and then immersed in a flame-retardant chemical solution tank at 30 ° C. or lower. After immersion, the plate is dried (). Thereafter, the surface plate material 1 and the base plate material 2 are bonded with an adhesive () and laminated to obtain a product.

More specifically, a boiling treatment is performed, for example, by boiling a plate material with hot water for 3 hours. In this case, even if the wood is a raw material, there is variation in the water content in the material, but the boiling makes the water content in the material uniform. In this case, it is advisable to add baking soda. Baking soda is antacid and contains weakly alkaline sodium bicarbonate as a main component, and is used for bleaching and the like. When a flame retardant treatment is applied to wood, the wood is discolored and loses its conventional color. Therefore, when boiling in water by adding baking soda as a pretreatment, discoloration is suppressed in the flame retardant treatment.

Immersion treatment The impregnation of the flame-retardant chemical by immersion is more effective for a longer time. However, it is said that as the immersion time increases, the rate of increase in the weight of the flame-retardant chemical solution due to injection decreases significantly. Therefore, the relationship between the immersion time and the fixed amount of the drug was examined, and the processing time was determined. The dipping time was, for example, 17 to 24 hours for sour walnut and 12 to 20 hours for china. Drying Drying is performed, for example, at 60 ° C. for 48 hours.

Therefore, according to this manufacturing method, since a complicated apparatus such as a vacuum pressurizing impregnating apparatus is not used for impregnation of the flame retardant chemical, it can be processed by a simple apparatus for immersion, so that the manufacturing becomes easier. The manufacturing efficiency is improved.
In other words, it is not the injection of liquid due to the contraction and expansion of air inside and outside the wood (forced impregnation), but the concentration between water, wood fiber and the chemical solution,
The wood can be impregnated with the flame-retardant chemical by diffusion and equilibrium of temperature.

Further, since the surface plate 1 is impregnated, the processing volume is reduced because the surface plate 1 has a small thickness when viewed from the whole, so that the entire flame retardant is made of a flame retardant chemical. As compared with the case where the treatment is performed, the inside can be sufficiently impregnated with the chemical solution, time can be saved, and the production efficiency can be improved accordingly.

According to the flame retardant manufactured in this manner, the surface plate 1 is sufficiently impregnated with the chemical solution to the inside, so that the flame retardancy can be improved accordingly.
Further, since the surface plate member 1 has two layers, the flame retardant performance on the front surface side is reliably ensured as compared with the case of a single sheet. Further, since the base plate 2 is not subjected to the flame retarding treatment, the number of processing steps is reduced, and the production efficiency is further improved. Furthermore, since the base plate member 2 is formed of a laminated material, the strength is high and the material is effectively used.

[0016]

Embodiments of the present invention will be described below. The flame retardant according to the example was produced based on the following test results. Basically, as will be described later, the flame-retardant chemical solution was impregnated with a vacuum pressure impregnating apparatus without using a vacuum pressure impregnating device or the like, and the flame-retardant performance was exhibited only by immersion in a chemical solution tank. Saw walnut, a soft hardwood from Iwate Prefecture, was used as a plate material to be impregnated with a flame retardant chemical.
The test results are shown below. The properties of the tested plate are as follows. Sample A. Japanese red pine test specimen (Iwate Prefecture, plantation forest) Dimensions L × R × T = 40 × 20 × 20 mm Properties Average annual ring width 3.8 mm Water content 120-150% (impregnation conditions: reduced pressure 50 torr, pressurized 5 kg / cm ² ) Sample B. Raw material of Sawagurumi (natural forest from Iwate Prefecture) Dimensions L × R × T = 230 × 136 × 4 mm Properties Total specific gravity 0.38-0.41 Water content 60-80% Sample C. Dried wood material of Sawagumi (Iwate Prefecture, natural forest) Dimensions L × R × T = 230 × 136 × 4mm Property Total specific gravity 0.38-0.41 Water content 5-12% Dry Drying schedule to finish water content 10% or less by. Further, as the flame retardant chemical, OK-2 manufactured by Marubishi Yuka Co., Ltd.
01 (55% non-volatile component) was used.

First, a comparative test on the immersion method was performed. There are four immersion methods: (1) a cold bath method, (2) a vacuum pressure impregnation method, (3) a warm bath method, and (4) a hot and cold bath method. (1) Cold bath method Sample A was immersed in a flame-retardant chemical at room temperature (18 ± 3 ° C) for 24 hours, and air-dried (18 ± 3 ° C, 24 hours). C., 80.degree. C., and 105.degree. C., and the drying was performed for 24 hours. (2) Vacuum pressure impregnation method Sample A is immersed in a flame-retardant chemical solution at ordinary temperature, and the pressure is reduced to 50 torr.
The injection was performed for 2 hours at a pressure of 5 kg / cm ² for 2 hours. (3) Warm bath method Samples A and B were immersed in a flame retardant solution at 60 ° C for 24 hours, and dried under substantially the same conditions as in the cold bath method. (4) Hot / cold bath method Samples A and B were boiled in water (100 ° C, 3 hours), and immediately thereafter, immersed in a flame-retardant chemical solution at room temperature (18 ± 3 ° C) for 24 hours. Drying was performed under the same conditions.

The fixed amount of the flame-retardant chemical solution was calculated as follows. C = W ₁ / V ₁ -W ₀ / V ₀ C: fixed amount of drug (Kg / m ³ ) W ₀ : untreated weight ( ₀ kg /) V ₀ : untreated volume (m ³ ) W ₁ : weight after treatment (Kg) V ₁ : Volume after treatment (m ³ )

FIG. 3 shows the amount of fixed drug for each treatment for each chemical liquid impregnation method. The sample impregnated with vacuum pressure had a drug fixed amount of about 450 kg / m ³ . In the treatment in a saturated state, a cold bath is 200 to 260 kg / m ³ , and a hot bath is about 300 kg / m ³ .
m ^3, Yutakahiyayoku about 210 kg / m ^3, the cold bath in the processing of the entire dry state 50~100Kg / m ^3, a water bath is from 150 to 1
80 kg / m ^3, Yutakahiyayoku became drug fixed amount of about 210 kg / m ^3. The rate of weight increase differs greatly between saturated and completely dry conditions. This suggests that the water content of the wood greatly affects the impregnation of the flame retardant chemical. However, the warm-cooled bath showed almost the same weight increase rate in both the saturated and completely dried samples, indicating that it was hardly affected by the water content. In the actual treatment, the untreated material is in an undried state, and it is considered that there is a large variation in the water content in each lot and each part. Therefore, it has been found that a hot / cold bath is advantageous as a treatment method from the homogenization of the water content on the surface by the pretreatment of boiling and the stability of the fixed amount of the flame-retardant drug.

From the above results, the flame-retardant material according to the example was prepared as follows. As shown in FIG. 4, the flame-retardant material had a laminated structure in which the two flame-retarded plate members were the surface plate members 1 and 1 and the untreated material was the base plate member 2 and had the dimensional relationship shown in FIG. In this flame-retardant material, the adhesive 3 of the surface plate 1 is "Oshika Resin No. 105" manufactured by Oshika Shinko Co., Ltd., two samples B are used as a flame-retardant treatment layer, and a sample C (laminate) is used as a base plate. Adhesive (coating amount 220-250 g / m ² )
And pressed (10 kg / cm ² , 24 hours). Thereafter, the cross-sectional shape shown in FIG. 4 was subjected to moulder processing, and the width was cut off to produce a flame retardant material.

Then, this flame retardant material is 22 cm × 22 cm.
Then, a combustion test (surface test) was performed on the test sample. The combustion test device uses a building material combustion test device manufactured by Toyo Seiki Co., Ltd.
No. 321 (August 25, 1977), JIS A132
Based on the 1-1975 flame-retardant material, the determination items shown in FIG. 5 were determined. The test results relating to the relationship between the fixed amount of the flame retardant drug and the performance are shown below. In order to examine the relationship between the fixed amount of the drug and the burning performance in Sawagurumi, the flame retardant treatment was carried out by a hot bath method or a hot / cold bath method, and a flame test of the flame retardant produced as a prototype using samples B and C was performed.

(A) AF (afterflame time) FIG. 6 shows the relationship between the amount of fixed medicine and AF. In the warm bath method, the fixed amount of the drug is distributed at 50 to 220 Kg / m ³ , and the AF tends to decrease as the fixed amount of the drug increases. AF is 0 when the drug fixed amount is about 100 to 150 kg / m ³ .
It is distributed in the range of ~ 140, and it is presumed that performance evaluation with a fixed amount of drug is difficult. 180-200Kg of fixed drug
When it exceeds / m ³ , AF becomes 0. In the hot / cold bath method, the drug fixed amount is distributed at 150 to 280 Kg / m ³ ,
All samples had AF = 0.

(B) CA (Smoke Emission Factor) FIG. 7 shows the relationship between the amount of drug fixed and CA. In the warm bath method, CA is distributed in a range of 15 to 60 regardless of the fixed amount of the drug. In the hot / cold bath method, CA is irrespective of the fixed amount of drug,
It is distributed over a width of 25 to 40. Since the reference value of CA for the flame retardant is 120 or less, the criteria are satisfied in each process. It can be seen that the variation in the performance of the hot and cold bath method is slightly smaller than that of the hot bath method.

(C) TC (ignition time) FIG. 8 shows the relationship between the fixed amount of drug and TC. In the warm bath method, TC tends to increase with an increase in the amount of fixed drug.
When the amount of drug fixed becomes 150 to 200 kg / m ³ or more, T
C = 0. In the hot / cold bath method, most of the samples showed TC = 360 under these experimental conditions, indicating that the sample was not ignited by the 6-minute heating test. Since the reference value of TC in the flame retardant is 180 or more, the reference is satisfied in each process.

(D) Tdθ (Temperature Time Area) FIG. 9 shows the relationship between the drug fixed amount and Tdθ. In the warm bath method, Tdθ tends to decrease as the amount of fixed drug increases. When the amount of fixed drug is 150 to 200 kg / m ³ or more, Tdθ = 0. In the hot and cold bath method, most of the samples show Tdθ = 0 under these experimental conditions. This indicates that the surface layer has performance equivalent to quasi-incombustibility. Since the reference value of Tdθ for the flame retardant is 350 or less, each process satisfies the reference.

The following findings were obtained from this test. (1) The hot / cold bath method is stable in processing under one condition with small variations in performance. (2) The hot / cold bath method can obtain a high drug fixing amount and has stable high flame retardancy. In addition, it satisfies all performance standards for surface testing of flame retardant materials. (3) The amount of fixed drug and the performance of Sawagurumi vary depending on the treatment, but the fixed amount of drug is about 180 to 200K.
g / m ³ or more satisfies the performance standard of the surface test of the flame retardant.

Further, based on the knowledge obtained in the above test,
The following guidelines have been obtained for the commercialization of flame retardant using Sawagurumi. (1) Sawagumi is suitable for flame retardant treatment. (2) The hot / cold bath method can be treated with a simple apparatus, and can provide a uniform moisture content and impart flame retardancy by pretreatment. In addition, the processing can be performed using raw materials, and the drying step can be performed only once. (3) A laminated structure in which a treated veneer is used as a surface layer and bonded to an untreated veneer can exhibit efficient flame retardancy.

Next, the processing conditions of the flame retardant were examined. Here, for the purpose of establishing the immersion conditions of the hot / cold bath method during the production, the concentration and the processing time were evaluated and examined.
The test materials were based on Samples B and C above. The flame-retardant chemical is OK-201 (non-volatile component 55, manufactured by Marubishi Yuka Co., Ltd.).
%)It was used. The processing time and the drug fixed amount were compared as follows. The treatment time was set to 0.5, 1, 3, 6, 12, 24, and 48 hours in accordance with the above-mentioned hot / cold bath method. According to the above-mentioned hot and cold bath method, the flame-retardant chemical solution concentration was 2.75, 5.50, 11.00, 27.50, 38.
50, 55.00%.

Comparison Results Amount of fixed drug by time FIG. 10 shows the relationship between the processing time and the amount of fixed drug. In the raw material processing time and the drug fixed amount, the processing time is 0.5, 1,
As it increases to 3,6,12,24,48 hours,
About 70,100,160,220,27
0, 310, 330 Kg / m ³ . From this, it can be seen that when the processing time reaches 24 hours, the degree of increase in the amount of drug fixed by immersion thereafter decreases. Therefore, it was found that it is efficient if the processing is performed in about 24 hours in the flame retarding processing of sour walnut. As for the immersion of the sky-dried material, it was found that the same amount of drug fixed as that of the raw material was exhibited in 24 and 48 hours, and that the raw material and the dried material could be treated by the hot and cold bath method when the material thickness was about 5 mm.

FIG. 11 shows the relationship between the concentration of the drug solution and the fixed amount of the drug. In the relationship between the concentration and the fixed amount of drug, the drug solution concentration is 2.75,5.
50, 11.00, 27.50, 38.50, 55.0
As the amount increased to 0%, the fixed amount of the drug became 10, 15,
50, 140, 250, and 400 Kg / m ³ , indicating that the concentration and the amount of fixed drug show a proportional relationship.
From the above fixed amount of the drug and the combustion performance, the required fixed amount of the drug has been obtained to be about 200 kg / m ³ , so it is estimated that the required concentration of the flame-retardant drug solution is around 38.5%. Is done. From these test results, it can be determined that, when sour walnut is subjected to a flame-retardant treatment by a hot / cold bath method, the conditions of concentration around 38.5% and treatment for 24 hours are optimal.

In the method for manufacturing a flame-retardant material for building according to the above embodiment, when impregnating with a flame-retardant chemical,
The board material was boiled with hot water and then immersed in a flame-retardant chemical bath at 30 ° C. or lower, according to the hot / cold bath method. However, the present invention is not limited to this method. At this time, a hot / cold bath method immersed in a flame-retardant chemical solution tank heated to 50 ° C. or higher may be used, and may be appropriately changed. Also,
In the flame-retardant material for construction according to the above-described embodiment, the base plate member 2 is formed using a glued laminated material, but is not necessarily limited to this. For example, as shown in FIG. It may be configured properly and may be changed as appropriate. Furthermore,
In the above-described embodiment and examples, the number of the surface plate members is two, but the present invention is not necessarily limited to this.
Needless to say, the number may be four or more, and the total number is not limited to three but may be four or more.

[0032]

As described above, according to the flame-retardant material for construction and the method for producing a flame-retardant material for construction of the present invention, at least two layers of the plate material on the front side are impregnated. Since the plate material is thinner than the entire plate thickness, the processing volume is smaller, and therefore, the chemical solution should be sufficiently impregnated into the inside compared to when the entire flame retardant material is treated with the flame retardant chemical solution. , And time can be saved, and accordingly, manufacturing efficiency can be improved. In addition, since the chemicals can be sufficiently impregnated into the inside of the plate material on the front side, the flame retardancy can be improved accordingly, and the number of layers is two or more. The flame retardant performance on the front side can be reliably ensured.
Furthermore, since the whole is formed in three or more layers, there is an effect that the strength is increased.

When the back plate is constituted as a base plate which is not impregnated with a flame-retardant chemical, the base plate does not need to be subjected to the flame-retardant treatment. Manufacturing efficiency can be improved.
In addition, when the back plate is formed of a glued laminated lumber in which a large number of wood pieces are joined via an adhesive, the strength can be further increased, and the material can be effectively used. There is an effect that can be.

Further, in the method for producing a flame retardant material for building,
In the case of using a warm bath method of immersing in a flame-retardant chemical solution tank heated to 50 ° C. or more, or a hot / cold bath method of immersing a plate material in a flame-retardant chemical solution tank of 30 ° C. or less after boiling with hot water, Since complicated equipment such as vacuum pressure impregnation equipment is not used for impregnation of flame retardant chemicals,
Because it can be processed with a simple device for immersion,
Manufacturing becomes easy, and manufacturing efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a flame retardant for construction according to an embodiment of the present invention.

FIG. 2 is a process chart showing a method for manufacturing a flame-retardant material for building according to an embodiment of the present invention.

FIG. 3 is a diagram showing the relationship between various flame-retardant chemical solution impregnation methods used in the method for producing a building flame-retardant material of the present invention and the amount of fixed medicine.

FIG. 4 is a cross-sectional view illustrating a building flame-retardant material according to an embodiment of the present invention.

FIG. 5 is a table showing combustion test items of a flame retardant for construction according to an example of the present invention.

FIG. 6 is a graph showing a relationship between a fixed amount of a chemical and a residual flame time of a flame retardant for construction according to an example of the present invention.

FIG. 7 is a graph showing a relationship between a fixed amount of a chemical and a smoke generation coefficient of a flame retardant for construction according to an example of the present invention.

FIG. 8 is a graph showing a relationship between a fixed amount of a chemical and an ignition time of a flame retardant for construction according to an example of the present invention.

FIG. 9 is a graph showing the relationship between the amount of fixed medicine of the flame retardant for building and the temperature time area according to the example of the present invention.

FIG. 10 is a graph showing the relationship between the impregnation time of the flame-retardant chemical solution and the fixed amount of the chemical according to the method for producing a building flame-retardant material of the present invention.

FIG. 11 is a graph showing the relationship between the concentration of a flame-retardant chemical solution and the fixed amount of the chemical according to the method for producing a building flame-retardant material of the present invention.

FIG. 12 is a cross-sectional view showing a building flame-retardant material according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Surface board material 2 Stand board material 3 Adhesive 4 Adhesive

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hironori Taniuchi 560 No. 11 Kiyomizu, Yazayama-cho, Yahaba-cho, Shiwa-gun, Iwate Prefecture Inside the Iwate Prefectural Forestry Technology Center (72) Inventor Shigeo Yamazaki Kubo-gun, Iwate Prefecture Yamagata Village, Shimohata 6th 47th

Claims (6)

[Claims] The present invention is characterized in that three or more wooden plate members are laminated via an adhesive, and at least a plate member forming two layers on the front side is formed as a surface plate member impregnated with a flame-retardant chemical. Flame retardant for construction. 2. The architectural flame-retardant material according to claim 1, wherein the back plate material is constituted as a base plate material not impregnated with a flame-retardant chemical solution. 3. The flame-retardant material for construction according to claim 1, wherein the back plate is formed of a laminated material in which a large number of wood pieces are joined together via an adhesive. 4. A method for manufacturing a flame-retardant material for building, wherein three or more wooden plate materials are laminated via an adhesive, wherein the plate material forming at least two layers on the front side is provided with a flame-retardant material in advance. A method for producing a flame-retardant material for building, which is impregnated with a chemical and then laminated. 5. The manufacturing method of a flame-retardant material for building according to claim 4, wherein the impregnating with the flame-retardant chemical solution comprises immersing the plate material in a flame-retardant chemical solution tank heated to 50 ° C. or higher. Method. 6. When impregnating the flame-retardant chemical solution,
5. The method for producing a flame retardant material for a building according to claim 4, wherein the plate material is boiled with hot water and then immersed in a flame-retardant chemical solution tank at 30 [deg.] C. or lower.