JP7080289B2 - Flame-retardant chemicals, non-combustible wood using them, and methods for adjusting flame-retardant chemicals - Google Patents

Description

The present invention relates to a flame-retardant chemical solution , a non-combustible wood using the same, and a method for adjusting the flame-retardant chemical solution .

In recent years, in order to expand the use of domestically produced wood, for example, non-combustible wood in which a wood base material such as natural wood is impregnated with a flame retardant chemical solution in which a flame retardant is dissolved has attracted attention.

For example, Patent Document 1 discloses a stable liquid composition of a boron compound containing boric acid and borax in an amount exceeding the solubility of each single compound.

Japanese Patent No. 5097983

By the way, in the liquid composition of a stable boron compound disclosed in Patent Document 1, boric acid and borax are dissolved in boiling water at 100 ° C., and the impregnation treatment of impregnating wood is performed at a high temperature (for example, 90 ° C. or higher). Since it is necessary to perform the impregnation process, the workability of the impregnation process is deteriorated.

The present invention has been made in view of this point, and an object of the present invention is to provide a flame-retardant chemical solution capable of impregnation treatment at a low temperature and a high concentration as much as possible.

In order to achieve the above object, the present invention contains a predetermined amount of ammonium borate in addition to boric acid and borax.

Specifically, the flame-retardant chemical solution according to the present invention contains 5 parts by mass to 75 parts by mass of boric acid, 10 parts by mass to 80 parts by mass of boric acid, and 1 part by mass to 50 parts by mass with respect to 100 parts by mass of water. It is characterized by containing parts by weight of ammonium borate and not containing ammonium phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, ammonium carbonate, ammonium hydrogen carbonate, potassium carbonate, ethylene glycol and polyethylene glycol . do.

According to the above configuration, 5 parts by mass to 75 parts by mass of boric acid, 10 parts by mass to 80 parts by mass of borax, and 1 part by mass to 50 parts by mass of ammonium borate with respect to 100 parts by mass of water. Is contained. Therefore, for example, it is possible to realize a flame-retardant chemical solution in which boric acid, borax and ammonium borate are dissolved in water at 80 ° C. at a high concentration and then solids are less likely to precipitate even when cooled to 60 ° C. As a result, the impregnation treatment of impregnating the wood substrate with the flame-retardant chemical solution can be performed at a low temperature of about 60 ° C., so that the flame-retardant chemical solution capable of impregnation treatment at a low temperature and a high concentration can be obtained. Can be provided.

The boron content may be 5 mol / L or more.

According to the above configuration, the flame retardant requirement that the total calorific value for 5 minutes does not exceed 8 MJ / m ² can be satisfied.

The boron content may be 11 mol / L or more.

According to the above configuration, the non-combustible requirement that the total calorific value for 20 minutes does not exceed 8 MJ / m ² can be satisfied.

Further, the non-combustible wood according to the present invention is characterized in that the wood base material is impregnated with the above-mentioned flame-retardant chemical solution.

According to the above configuration, for example, when the content of boron in the flame-retardant chemical solution is 11 mol / L or more, the nonflammability of non-combustible wood can be ensured.

Further, the method for preparing the flame-retardant chemical solution according to the present invention is the method for preparing the flame-retardant chemical solution described above, wherein the boric acid, the borax and the above-mentioned boric acid, the above-mentioned borax and the above-mentioned water in the water heated to 70 ° C. to 80 ° C. It is characterized in that ammonium borate is added and dissolved.

According to the present invention, since a predetermined amount of ammonium borate is contained in addition to boric acid and borax, a flame-retardant chemical solution capable of impregnation treatment at a low temperature and a high concentration as possible is provided. be able to.

It is sectional drawing of the non-combustible wood impregnated with the flame-retardant chemical liquid which concerns on 1st Embodiment of this invention. It is a table which shows the maximum dissolution amount of ammonium borate in each composition of boric acid / borax in the flame retardant chemical solution which concerns on 1st Embodiment of this invention. It is a table which shows the solubility in each composition of boric acid / borax when ammonium borate is not added (0 part by mass) in the flame retardant chemical solution which concerns on 1st Embodiment of this invention. It is a table which shows the solubility in each composition of boric acid / borax in the case of addition of ammonium borate (15 parts by mass) in the flame retardant chemical solution which concerns on 1st Embodiment of this invention. It is a table which shows the solubility in each composition of boric acid / borax in the case of addition of ammonium borate (30 parts by mass) in the flame retardant chemical solution which concerns on 1st Embodiment of this invention. It is a table which shows the solubility in each composition of boric acid / borax in the case of addition of ammonium borate (50 parts by mass) in the flame retardant chemical solution which concerns on 1st Embodiment of this invention. It is a graph which shows the relationship between the amount of solids of a chemical solution in the flame-retardant chemical solution which concerns on 1st Embodiment of this invention, and the total calorific value of the exothermic test. It is a table which shows the relationship between the boron molar concentration in the flame retardant chemical solution which concerns on 1st Embodiment of this invention, and the total calorific value of the exothermic test. It is a graph which shows the hygroscopicity of the non-combustible wood which used the flame-retardant chemical liquid which concerns on 1st Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail. The present invention is not limited to the following embodiments.

<< First Embodiment >>
1 to 3 show a first embodiment of a flame-retardant chemical solution according to the present invention and non-combustible wood using the same. Here, FIG. 1 is a cross-sectional view of the non-combustible wood 10 impregnated with the flame-retardant chemical solution of the present embodiment.

As shown in FIG. 1, the non-combustible wood 10 includes a wood base material 5 and a flame retardant 6 impregnated inside the wood base material 5.

The wood base material 5 is, for example, solid wood, laminated wood, plywood, LVL (Laminated Veneer Lumber), particle board, or the like. Further, the tree species constituting the wood base material 5 are not limited, and for example, hard tree species such as oak, birch, beach, and cherry, and soft tree species such as sugi, hemlock, cypress, and pterocarya rhois are used.

The flame retardant 6 is a solute dissolved in the flame retardant chemical solution of the present embodiment. Here, the flame-retardant chemical solution of the present embodiment has 5 parts by mass to 75 parts by mass of boric acid (B (OH) ₃ ) 10 with respect to 100 parts by mass of water, based on the results of experiments described later. From 1 part by mass to 80 parts by mass of boric acid (Na ₂ B ₄ O _{7.10H 2} O) and 1 part to 50 parts by mass of ammonium borate ((NH ₄ ) ₂ O ・ 5B ₂ O _{3.8H 2} O) ) Is contained. Further, in the flame-retardant chemical solution of the present embodiment, the boron content is 5 mol / L or more, preferably 11 mol / L or more. The water used for the flame-retardant chemical solution of the present embodiment is not particularly limited, but is ion-exchanged water, distilled water, tap water, industrial water, and the like.

The non-combustible wood 10 having the above constitution is made of wood after preparing a flame-retardant chemical solution by adding a predetermined amount of boric acid, borax and ammonium borate to water heated to about 80 ° C. with stirring. It can be produced by impregnating the base material with a flame-retardant chemical solution at about 60 ° C. and drying it. Here, in the impregnation treatment, the wood substrate 5 is housed in a pressure vessel (chamber) capable of depressurizing and pressurizing the inside of the container, and a predetermined pressure (for example, about −0.7 atm (−0.709 MPa)). After removing the air contained in the conduit or the like in the wood substrate 5, the flame-retardant chemical solution is injected into the chamber and pressurized to a predetermined pressure (for example, about 10 atm (1.013 MPa)). The voids of the wood substrate 5 are impregnated with a flame-retardant chemical solution.

Next, in the flame-retardant chemical solution of the present embodiment, the reason why the content of ammonium borate with respect to 100 parts by mass of water is 1 part by mass to 50 parts by mass will be described based on a specific experiment. Here, FIG. 2 is a table showing the maximum dissolution amount of ammonium borate in each formulation of boric acid / borax in the flame-retardant chemical solution of the present embodiment.

First, as shown in the table of FIG. 2, a predetermined amount (0 parts by mass, 5 parts by mass, 15 parts by mass, 30 parts by mass) of boric acid and a predetermined amount (0 parts by mass) are added to 100 parts by mass of water at 80 ° C. The content (maximum dissolution amount) of ammonium borate, which can be dissolved in each aqueous solution in which borosand (parts, 20 parts by mass, 35 parts by mass, and 50 parts by mass) is dissolved and solid content does not precipitate even at 60 ° C., was determined. .. Here, as an experimental result, as shown in the table of FIG. 2, when 5 parts by mass of boric acid and 20 parts by mass of borax are dissolved in 100 parts by mass of water at 80 ° C., 60 parts are dissolved. It was found that 50 parts by mass of ammonium borate can be dissolved at the maximum without precipitation at ° C.

Further, in an aqueous solution (boron molar concentration: 3.0 mol / L) in which 9 parts by mass of boric acid and 15 parts by mass of borax are dissolved in 100 parts by mass of water at 80 ° C., the aqueous solution is adjusted to 5 ° C. Upon cooling, solids were deposited. However, an aqueous solution in which 9 parts by mass of boric acid, 13 parts by mass of hosand, and 1 part by mass of ammonium borate are dissolved in 100 parts by mass of water at 80 ° C. (molar concentration of boron: 3.0 mol / L). ), The solid content did not precipitate even when the aqueous solution was cooled to 5 ° C. As a result, in a flame-retardant chemical solution having the same molar concentration of boron, boric acid, borax and borax are added by adding 1 mass or more of ammonium borate, rather than adjusting with only two types of boric acid and borax. It was found that it was more difficult to precipitate even at lower temperatures when adjusted with three types of ammonium acid.

Therefore, the content of ammonium borate with respect to 100 parts by mass of water is 1 part by mass to 50 parts by mass.

Next, as shown in the tables of FIGS. 3 to 6, a predetermined amount of boric acid, a predetermined amount of borax, and a predetermined amount of ammonium borate are dissolved in 100 parts by mass of water at 80 ° C. to 60 ° C. It was examined that the solid content was precipitated (x in the table) / not precipitated (◯ in the table).

As an experimental result, as the amount of ammonium borate added increases, the region ◯ (hatching part) in each table of FIGS. 3 to 6 shifts to the upper side in the table, so ammonium borate should be added. It was found that, in particular, borax can be dissolved at a high concentration, and there is a synergistic effect between ammonium borate and borax. Specifically, in the range where boric acid is 5 parts by mass to 15 parts by mass and borax is 40 parts by mass to 60 parts by mass, solid content is precipitated at 60 ° C. when ammonium borate is not added. However, by adding 50 parts by mass of ammonium borate, the solid content did not precipitate at 60 ° C.

Next, the reason why the boron content of the flame-retardant chemical solution of the present embodiment is 11 mol / L or more will be described based on a specific experiment. Here, FIG. 7 is a graph showing the relationship between the solid content of the chemical solution in the flame-retardant chemical solution of the present embodiment and the total calorific value of the exothermic test.

First, a flame-retardant chemical solution prepared by dissolving 45 parts by mass of boric acid and 35 parts by mass of borax in 100 parts by mass of water at 80 ° C. was prepared, and the flame-retardant chemical solution was prepared to have thicknesses of 22 mm and 30 mm. Incombustible wood was produced by impregnating LVL. In this experimental example, the non-combustible wood having a thickness of 22 mm is a white square mark in the graph of FIG. 7, and the non-combustible wood having a thickness of 30 mm is a white circle mark in the graph of FIG.

Further, a flame-retardant chemical solution prepared by dissolving 45 parts by mass of boric acid, 35 parts by mass of borax, and 15 parts by mass of ammonium borate in 100 parts by mass of water at 80 ° C. was prepared to make the flame-retardant. Non-combustible wood was prepared by impregnating LVL having a thickness of 22 mm and 30 mm with a chemical solution. In this experimental example, the non-combustible wood having a thickness of 22 mm is a filled square mark in the graph of FIG. 7, and the non-combustible wood having a thickness of 30 mm is a filled circle mark in the graph of FIG.

For the non-combustible wood (length 100 mm × width 100 mm) produced as described above, the total calorific value for 20 minutes was measured using a cone calorimeter tester compliant with ISO5660-1.

As the experimental results, as shown in the graph of FIG. 7, boric acid / borax-based flame retardants and boric acid / borax / ammonium borate flame retardants are summarized regardless of the thickness of LVL. It was found that the solid content of the flame retardant chemical solution must be 280 kg / m ³ or more in order to prevent the total calorific value from exceeding 8 MJ / m ² . Here, the solid content of the flame-retardant chemical solution of 280 kg / m ³ or more corresponds to 10.9 mol / L or more in terms of the molar concentration of boron. The content may be 11 mol / L or more.

Next, the reason why the boron content of the flame-retardant chemical solution of the present embodiment is 5 mol / L or more will be described based on a specific experiment. Here, FIG. 8 is a table showing the relationship between the molar concentration of boron in the flame-retardant chemical solution of the present embodiment and the total calorific value of the exothermic test.

Specifically, as shown in the table of FIG. 8, a flame-retardant chemical solution (5 types in total) in which a predetermined amount of boric acid, borax and ammonium borate are dissolved in 100 parts by mass of water at 70 ° C. After adjustment, these flame-retardant chemicals were impregnated into LVL having a thickness of 22 mm, respectively, to prepare five kinds of non-combustible wood. Then, the total calorific value for 5 minutes was measured for the five types of non-combustible wood (length 100 mm × width 100 mm) produced using a cone calorimeter tester compliant with ISO5660-1.

As a result of the experiment, as shown in the table of FIG. 8, the molar concentration of boron must be 5 mol / L or more in order to prevent the flame retardant requirement, that is, the total calorific value for 5 minutes does not exceed 8 MJ / m ² . It turned out to be. Here, if the molar concentration of boron is 3 mol / L, the total calorific value for 5 minutes may exceed 8 MJ / m ² as shown in the table of FIG. 8, and the flame-retardant requirement may not be satisfied. ..

Next, the hygroscopicity of non-combustible wood using the flame-retardant chemical solution of the present embodiment was evaluated. Here, FIG. 9 is a graph showing the hygroscopicity of non-combustible wood using the flame-retardant chemical solution of the present embodiment.

First, a flame-retardant chemical solution prepared by dissolving 45 parts by mass of boric acid and 35 parts by mass of borax in 100 parts by mass of water at 80 ° C. was prepared, and the flame-retardant chemical solution (without ammonium borate added) was prepared. Was impregnated into LVL having a thickness of 30 mm to prepare non-combustible wood.

Further, a flame-retardant chemical solution (added with ammonium borate) prepared by dissolving 45 parts by mass of boric acid, 35 parts by mass of borax, and 15 parts by mass of ammonium borate in 100 parts by mass of water at 80 ° C. Then, the flame-retardant chemical solution was impregnated into LVL having a thickness of 30 mm to prepare non-combustible wood.

The non-combustible wood (length 100 mm x width 100 mm) produced as described above is dried at 60 ° C. until it reaches a constant weight, and then placed in a constant temperature and humidity chamber set at a temperature of 40 ° C. and a relative humidity of 90% for a predetermined time. The hygroscopicity was measured by measuring the weight after the lapse. Here, in the graph of FIG. 9, the non-combustible wood using the flame-retardant chemical solution containing ammonium borate is a filled circle, and the non-combustible wood using the flame-retardant chemical solution not added ammonium borate is white. It is a circle without a circle.

As a result of the experiment, as shown in the graph of FIG. 9, 15 parts by mass of a flame-retardant chemical solution prepared by dissolving 45 parts by mass of boric acid and 35 parts by mass of borax in 100 parts by mass of water at 80 ° C. It was found that the moisture absorption rate after 200 hours was reduced by about 2% by adding the borax ammonium borate. Here, when general non-combustible wood has high hygroscopicity, problems such as whitening and leaching occur in which the flame-retardant chemical liquid exudes to the surface due to moisture absorption and desorption. These problems are less likely to occur as the hygroscopicity of non-combustible wood using flame-retardant chemicals is as low as possible. Therefore, adding ammonium borate to lower the hygroscopicity is advantageous in suppressing the occurrence of white flowers and efflorescence.

As described above, according to the flame-retardant chemical solution of the present embodiment, 5 parts by mass to 75 parts by mass of boric acid, 10 parts by mass to 80 parts by mass of borax, and 10 parts by mass of borax with respect to 100 parts by mass of water. It contains 1 part by mass to 50 parts by mass of ammonium borate. Therefore, for example, it is possible to realize a flame-retardant chemical solution in which boric acid, borax and ammonium borate are dissolved in water at 80 ° C. at a high concentration and then solids are less likely to precipitate even when cooled to 60 ° C. As a result, the impregnation treatment of impregnating the wood substrate 5 with the flame-retardant chemical solution can be performed at a low temperature of about 60 ° C., so that the flame-retardant chemical solution can be impregnated at a low temperature and a high concentration as much as possible. Can be provided.

Further, according to the flame-retardant chemical solution of the present embodiment, when the boron content is 5 mol / L or more, the flame-retardant requirement that the total calorific value for 5 minutes does not exceed 8 MJ / m ² is satisfied. Can be met.

Further, according to the flame-retardant chemical solution of the present embodiment, when the boron content is 11 mol / L or more, the non-combustible requirement that the total calorific value for 20 minutes does not exceed 8 MJ / m ² is satisfied. be able to.

Further, according to the non-combustible wood using the flame-retardant chemical solution of the present embodiment, in addition to boric acid and borax, a flame-retardant chemical solution in which a predetermined amount of ammonium borate is dissolved as a main component is used. It is possible to lower the moisture absorption rate as compared with non-combustible wood using a flame-retardant chemical solution in which boric acid and borax are dissolved as main components, and it is possible to suppress the occurrence of efflorescence and leaching.
<< Other Embodiments >>
In the first embodiment described above, a flame-retardant chemical solution in which boric acid, borax and ammonium borate are dissolved in water, and non-combustible wood using the same are exemplified. In addition to ammonium borate, it can also be applied to flame-retardant chemicals in which other auxiliaries are dissolved in water, and non-combustible wood using it.

In the first embodiment, the non-combustible wood using the flame-retardant chemical solution is exemplified, but the flame-retardant chemical solution of the present invention can also be applied to paper, clothing and the like.

As described above, the present invention is extremely useful because the impregnation treatment for producing non-combustible wood can be performed at a temperature as low as possible.

Claims (5)

With respect to 100 parts by mass of water, 5 parts by mass to 75 parts by mass of boric acid, 10 parts by mass to 80 parts by mass of boric acid, and 1 part by mass to 50 parts by mass of ammonium borate are contained, and ammonium phosphate is contained. , Diammonium dihydrogen phosphate, ammonium dihydrogen phosphate, ammonium carbonate, ammonium hydrogen carbonate, potassium carbonate, ethylene glycol and polyethylene glycol are not contained in the flame-retardant chemical solution. In the flame-retardant chemical solution according to claim 1,
A flame-retardant chemical solution characterized by having a boron content of 5 mol / L or more. In the flame-retardant chemical solution according to claim 1,
A flame-retardant chemical solution characterized by having a boron content of 11 mol / L or more. A non-combustible wood, wherein the wood substrate is impregnated with the flame-retardant chemical solution according to any one of claims 1 to 3. The method for preparing a flame-retardant chemical solution according to any one of claims 1 to 3.
A method for preparing a flame-retardant chemical solution, which comprises adding the boric acid, borax and ammonium borate to the water heated to 70 ° C. to 80 ° C. and dissolving them.

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