Aqueous solution, flame retardant material, and method for producing polyborate ion aqueous solution

Abstract

This invention provides an aqueous solution that exhibits excellent resistance to dripping and efflorescence when impregnated into materials, as well as excellent storage stability. [Solution] The aqueous solution of the present invention is an aqueous solution of a composition containing the following components (A) and (B), wherein the elemental ratio (molar ratio) of boron and phosphorus [B / P] is 0.33 / 1 to 5.6 / 1. Preferably, the ratio of component (A) to the total amount of solids in the aqueous solution is 25 to 85% by mass on an anhydrous basis. Ingredient (A): Polyborate ions Ingredient (B): Water-soluble phosphate

Description

Technical Field

[0001] The present invention relates to a method for producing an aqueous solution, a flame retardant material, and an aqueous solution of polyborate ions. More specifically, the present invention relates to an aqueous solution containing polyborate ions and a phosphorus compound, which is impregnated into a material for use, a flame retardant material impregnated with the aqueous solution, and a method for producing the above aqueous solution of polyborate ions.

Background Art

[0002] Conventionally, in order to impart flame retardancy or non-combustibility to combustible materials such as wood, a technique of impregnating the material with a flame retardant to make it flame retardant or non-combustible has been known. Borate-based compounds and phosphate-based compounds may be used as such flame retardants.

[0003] In the flame retardant material, when it absorbs moisture, a phenomenon called "bleeding" may occur in which the flame retardant elutes on the material surface. Further, when the bled liquid dries and solidifies thereafter, a phenomenon called "efflorescence" occurs.

[0004] Since borate-based compounds are less likely to absorb moisture, materials flame-retarded with a flame retardant using a borate-based compound are less likely to experience bleeding and efflorescence. However, borate-based compounds have low water solubility and are difficult to increase in concentration. Therefore, it takes time and effort to impregnate the material and flame retard the material. On the other hand, phosphate-based compounds have high water solubility and are easy to impregnate into the material, but bleeding and efflorescence are likely to occur.

[0005] Here, a technique of improving water solubility by using boric acid and borax in a specific ratio is known (see Patent Documents 1 and 2). Further, a flame retardant using a combination of a borate-based compound and a phosphate-based compound is known (see Patent Documents 3 and 4).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] However, the flame retardants disclosed in Patent Documents 1 to 4 have problems such as insufficient suppression of liquid dripping and poor storage stability due to crystallization during storage (especially in low-temperature environments).

[0008] Therefore, an object of the present invention is to provide an aqueous solution that exhibits excellent resistance to liquid dripping and efflorescence when impregnated into a material, and has excellent storage stability. Another object of the present invention is to provide a flame-retardant material that exhibits excellent resistance to liquid dripping and efflorescence. Furthermore, an object of the present invention is to provide a method for producing a polyborate ion aqueous solution that can be used in the production of the above aqueous solution and has excellent storage stability. [Means for solving the problem]

[0009] The present invention provides an aqueous solution of a composition containing the following components (A) and (B), wherein the elemental ratio (molar ratio) of boron and phosphorus [B / P] is 0.33 / 1 to 5.6 / 1. Ingredient (A): Polyborate ions Ingredient (B): Water-soluble phosphate

[0010] The above component (A) is preferably a polycondensate of a composition containing the following components (A1) and (A2). Component (A1): Boron-containing compound Component (A2): A boron-containing compound different from component (A1) above.

[0011] The above component (A1) is boric acid, and the above component (A2) is preferably borax.

[0012] The solid content of the above aqueous solution is preferably 15% by mass or more.

[0013] The ratio of the above component (A) to the total amount of the solid content is preferably 25 to 85% by mass in terms of anhydride.

[0014] The ratio of the above component (B) to the total amount of the solid content is preferably 15 to 75% by mass in terms of anhydride.

[0015] The above composition preferably contains two or more kinds of the above component (B).

[0016] The above component (B) is preferably at least one selected from the group consisting of diammonium hydrogen phosphate, ammonium dihydrogen phosphate, disodium hydrogen phosphate, sodium dihydrogen phosphate, and guanidine phosphate.

[0017] The solid content of the above aqueous solution is preferably 20% by mass or more.

[0018] The above aqueous solution is preferably a flame retardant for wood.

[0019] Further, the present invention provides a flame retardant material containing a composition containing the following component (A) and the following component (B), and having an elemental ratio (molar ratio) [B / P] of boron and phosphorus of 0.33 / 1 to 5.6 / 1. Component (A): Polyborate ion Component (B): Water-soluble phosphate

[0020] Further, the present invention provides a method for producing an aqueous solution of polyborate ions, which comprises adding the following component (A1), the following component (A2), and the following component (B) to water, and heating and dissolving them to obtain polyborate ions. Component (A1): Boron-containing compound Component (A2): A boron-containing compound different from the above component (A1) Component (B): Water-soluble phosphate

[0021] It is preferable to perform the above heating at a temperature of 60°C or higher.

Advantages of the Invention

[0022] The aqueous solution of the present invention is excellent in liquid dripping resistance and efflorescence resistance when impregnated into materials, and has excellent storage stability. Further, the flame-retardant material of the present invention is excellent in liquid dripping resistance and efflorescence resistance. Further, the polyborate ion aqueous solution obtained by the method for producing a polyborate ion aqueous solution of the present invention can be used for producing the aqueous solution of the present invention and has excellent storage stability.

Embodiments for Carrying Out the Invention

[0023] [Aqueous solution] The aqueous solution of the present invention is an aqueous solution of a composition containing at least the following component (A) and the following component (B). That is, the aqueous solution of the present invention is an aqueous solution in which the above composition is dissolved in water. Component (A): Polyborate ion Component (B): Water-soluble phosphate

[0024] The polyborate ion as component (A) is a polycondensate (condensed borate ion) of two or more boron-containing compounds. For example, pyrophosphate ions corresponding to a condensate of two molecules of boric acid, triborate ions corresponding to a linear condensate of three molecules of boric acid, and salts thereof can be mentioned. The two or more boron-containing compounds constituting the polyborate ion may be only one kind or two or more kinds.

[0025] The above polyborate ion may form a salt with a hydrogen ion or a metal ion such as a sodium ion, calcium ion, barium ion, zinc ion, or ammonium ion.

[0026] Component (A) is preferably a polycondensate of a composition containing the following component (A1) and the following component (A2). Component (A1): Boron-containing compound Component (A2): A boron-containing compound different from component (A1) above.

[0027] The composition containing the above components (A1) and (A2) is composed of a boron-containing compound. The above composition may contain only one type of component (A2) or two or more types.

[0028] The boron-containing compounds in component (A1) and component (A2) are compounds having boron as a constituent element. Preferred boron-containing compounds are compounds consisting of a boron atom, a hydrogen atom, and an oxygen atom, or salts thereof. Examples of such boron-containing compounds include boric acid; borax; boron oxide; orthoborates such as InBO3 and Mg3(BO3)2; diborates such as Mg2B2O5 and Co2B2O5; metaborates such as NaBO2·2H2O, NaBO2·4H2O, KBO2, LiBO2, and Ca(BO2)2; tetraborates such as Na2B4O7·5H2O; pentaborates such as KB5O8·4H2O and NH4B5O8·4H2O; and Na2B8O 13 Examples include octaborates such as 4H2O; Mokubo Beneserve (trade name). In particular, component (A1) is preferably boric acid and component (A2) is preferably borax.

[0029] The boric acid mentioned above may be H3BO3 (orthoboric acid, B(OH)3) or HBO2 (metaboric acid). Only one type of boric acid may be used, or two or more types may be used.

[0030] The borax described above is a compound represented as "Na2B4O5(OH)4·8H2O," and can also be represented as "Na2B4O7·10H2O." Furthermore, the borax described above does not necessarily have to be a hydrate in the aqueous solution of the present invention; it may also be an anhydrous form (Na2B4O7). Only one type of borax may be used, or two or more types may be used.

[0031] The boric acid mentioned above can also be obtained by adding acid to borax, and borax can also be obtained by adding sodium hydroxide to boric acid. Therefore, the aqueous solution in which component (A) is dissolved may be one to which a composition containing boric acid and / or borax has been added, or it may be one synthesized in water by adding a composition containing components that are raw materials for boric acid and / or borax to water.

[0032] The water-soluble phosphate, which is component (B), is preferably soluble in water at 25°C at a concentration of 1% by mass or more. Examples of component (B) include ammonium dihydrogen phosphate, diammonium hydrogen phosphate, triammonium phosphate, sodium dihydrogen phosphate, disodium hydrogen phosphate, trisodium phosphate, guanidine phosphate, polyphosphate, and polycarbamate phosphate. In the aqueous solution of the present invention, component (B) may be an anhydrous or hydrated form. Component (B) may be used alone or two or more types.

[0033] From the viewpoint of excellent pH buffering performance, it is preferable to use two or more components (B). In particular, it is preferable that component (B) be one or more (especially two or more) selected from the group consisting of diammonium hydrogen phosphate, ammonium dihydrogen phosphate, disodium hydrogen phosphate, sodium dihydrogen phosphate, and guanidine phosphate. Furthermore, from the viewpoint of reducing efflorescence and dripping, it is preferable that component (B) be three or more phosphates, including those with a solubility of 25 g or less per 100 g of water at 25°C.

[0034] The aqueous solution in which component (B) is dissolved may be prepared by adding a composition containing component (B), or it may be prepared by adding a composition containing, for example, phosphoric acid and a neutralizing agent such as ammonia to water and synthesizing it in water.

[0035] The elemental ratio (molar ratio) [B / P] of boron and phosphorus in the aqueous solution of the present invention is 0.33 / 1 to 5.6 / 1, preferably 0.35 / 1 to 5.0 / 1, more preferably 0.37 / 1 to 4.0 / 1, and even more preferably 0.4 / 1 to 2.0 / 1. When the above elemental ratio is 0.33 / 1 or higher, excellent resistance to dripping is achieved. When the above elemental ratio is 5.6 / 1 or lower, excellent storage stability (especially storage stability in low-temperature environments) is achieved.

[0036] The aqueous solution of the present invention contains water. The solid content (solid content concentration) of the aqueous solution of the present invention is preferably 15% by mass or more, and more preferably 20% by mass or more. A higher solid content allows more components (A) and (B) to be impregnated into the material in a shorter time, resulting in superior flame retardancy of the flame-retardant material. The solid content is, for example, 60% by mass or less, and may also be 50% by mass or less, or 40% by mass or less.

[0037] The aqueous solution of the present invention may contain a boron-containing compound that has not undergone polycondensation (for example, component (A1) and / or component (A2)). The boron-containing compound that has not undergone polycondensation may be referred to as a "free boron-containing compound."

[0038] The proportion of component (A) in the aqueous solution of the present invention is preferably 25 to 85% by mass, more preferably 30 to 80% by mass, and even more preferably 35 to 75% by mass, based on the total amount of solids (100% by mass) of the aqueous solution of the present invention, on an anhydrous basis. When the above proportion is 25% by mass or more, the resistance to dripping is superior. When the above proportion is 85% by mass or less, the storage stability is superior. Furthermore, if the aqueous solution of the present invention contains a free boron-containing compound, the above proportion is the total proportion of component (A) and the free boron-containing compound (on an anhydrous basis). In this specification, the amount of boric acid is intended to be the amount as H3BO3, and the amount of borax is intended to be the amount as an anhydrous (Na2B4O7). The above proportion can be calculated in detail by the formula described in the examples.

[0039] The proportion of component (B) in the aqueous solution of the present invention is preferably 15 to 75% by mass, more preferably 20 to 70% by mass, and even more preferably 25 to 65% by mass, based on the total amount of solids (100% by mass) of the aqueous solution of the present invention, on an anhydrous basis. When the above proportion is 15% by mass or more, storage stability (especially storage stability under low-temperature environments) is superior. When the above proportion is 75% by mass or less, resistance to dripping is superior.

[0040] The aqueous solution of the present invention may contain components other than component (A), component (B), and the free boron-containing compound. Examples of the other components include flame retardants and impregnation accelerators other than component (A), component (B), and the free boron-containing compound. Examples of the impregnation accelerators include alcohols such as methanol, ethanol, propanol, butanol, pentanol, and hexanol; diols such as ethylene glycol and propylene glycol; triols such as glycerin; polyols such as algitol having 3 to 11 carbon atoms, polyphenols, and surfactants. The total ratio of component (A), component (B), and the free boron-containing compound to the total amount (100% by mass) of the flame retardants is preferably 80% by mass or more, more preferably 90% by mass or more, and may be 95% by mass or more, 98% by mass or more, or 99% by mass or more, on an anhydrous basis. One or more of the other components may be used.

[0041] The total proportion of component (A), component (B), and the free boron-containing compound in the aqueous solution of the present invention is preferably 20% by mass or more, more preferably 22% by mass or more, and even more preferably 25% by mass or more, based on the total amount (100% by mass) of the aqueous solution of the present invention in terms of anhydrous form. A higher proportion allows for the impregnation of more component (A) and component (B) into the material in a shorter time, resulting in superior flame retardancy of the flame-retardant material. From the viewpoint of superior efflorescence resistance, the proportion is preferably 40% by mass or less, and more preferably 35% by mass or less.

[0042] [Method for producing aqueous solution] The aqueous solution of the present invention can be produced by known or conventional methods. For example, it can be produced by adding a composition containing component (A), component (B), and optionally other components to water, stirring and mixing, and dissolving the composition in water. Alternatively, as described above, one or more of components (A) and (B) may be synthesized in water by adding a composition containing raw materials capable of producing those components to water. Stirring and mixing may be carried out under heating, or undissolved substances may be removed.

[0043] For example, a boron-containing compound (preferably components (A1) and (A2)) and component (B) for forming component (A) may be added to water, and the mixture may be heated and dissolved to obtain polyborate ions, which are component (A), thereby producing an aqueous solution of polyborate ions (the aqueous solution of the present invention). By heating and dissolving, polyborate ions are easily generated, and an aqueous solution with excellent storage stability can be prepared.

[0044] The heating temperature described above is preferably 50°C or higher, and more preferably 60°C or higher, from the viewpoint of excellent solubility of the various components. Furthermore, while the temperature is not particularly limited, it is preferably 100°C or lower.

[0045] The aqueous solution of the present invention can impart flame retardancy or non-combustibility to materials. For this reason, the aqueous solution of the present invention can be used as a flame retardant for materials. Examples of such materials include wood, paper, woven fabrics, nonwoven fabrics, and resins. Among these, wood is preferred. In other words, the aqueous solution of the present invention is preferably used as a flame retardant for wood.

[0046] Examples of wood materials include cedar, spruce, cypress, paulownia, plywood, zelkova, SPF laminated timber (a composite material made by laminating spruce, pine, and fir), and bamboo. Examples of paper materials include Japanese paper, fusuma paper, and Western-style paper. Examples of woven fabrics include cotton cloth, polyester woven fabric, and PET fiber cloth. Examples of nonwoven fabrics include polyester nonwoven fabric. Examples of resins include SBR (styrene-butadiene rubber) latex, NBR (acrylonitrile-butadiene rubber) latex, polyvinyl acetate, polyvinyl alcohol, ABS (acrylonitrile-butadiene styrene) resin, EAA (ethylene-acrylic acid copolymer) resin, polyethylene film, polyurethane resin, PET (polyethylene terephthalate) film, and polyethylene sheet.

[0047] [Flame-retardant materials] A flame-retardant material can be manufactured by impregnating the above material with an aqueous solution of the present invention. The flame-retardant material includes a composition comprising the above components (A) and (B), wherein the elemental ratio (molar ratio) of boron and phosphorus [B / P] is 0.33 / 1 to 5.6 / 1.

[0048] The above flame-retardant material comprises the above material and the above composition impregnated into the above material. The elemental ratio (molar ratio) [B / P] of boron and phosphorus in the above composition is 0.33 / 1 to 5.6 / 1, preferably 0.35 / 1 to 5.0 / 1, more preferably 0.37 / 1 to 4.0 / 1, and even more preferably 0.4 / 1 to 2.0 / 1. When the above elemental ratio is 0.33 / 1 or higher, excellent resistance to liquid dripping is obtained.

[0049] The proportion of component (A) in the above flame retardant material is preferably 25 to 85% by mass, more preferably 30 to 80% by mass, and even more preferably 35 to 75% by mass, based on the total amount (100% by mass) of the above composition, on an anhydrous basis. When the above proportion is 25% by mass or more, the resistance to liquid dripping is superior. Furthermore, if the above composition contains a free boron-containing compound, the above proportion is the total proportion (on an anhydrous basis) of component (A) and the free boron-containing compound.

[0050] The proportion of component (B) in the above flame retardant material is preferably 15 to 75% by mass, more preferably 20 to 70% by mass, and even more preferably 25 to 65% by mass, based on the total amount (100% by mass) of the above composition. When the above proportion is 75% by mass or less, the resistance to liquid dripping is even better.

[0051] The above composition may contain other components besides component (A), component (B), and the free boron-containing compound. Examples of these other components are those described and illustrated as other components that may be included in the aqueous solution composition of the present invention. The total ratio of component (A), component (B), and the free boron-containing compound to the total amount (100% by mass) of the flame retardant in the above composition is preferably 80% by mass or more, more preferably 90% by mass or more, and may be 95% by mass or more, 98% by mass or more, or 99% by mass or more, on an anhydrous basis. One or more of these other components may be used.

[0052] The total proportion of component (A), component (B), and the free boron-containing compound in the above composition is preferably 80% by mass or more, more preferably 85% by mass or more, and even more preferably 90% by mass or more, based on the total amount of the above composition (100% by mass), on an anhydrous basis. A higher proportion results in superior flame retardancy of the flame retardant material.

[0053] The impregnation amount of the above composition in the above flame-retardant material is 120 kg / m³. 3 The above is preferable, and more preferably 150 kg / m 3 More preferably 200 kg / m 3 That concludes the explanation. The above impregnation amount is 120 kg / m³. 3 The above results in superior flame retardancy of the flame-retardant material. The above impregnation amount can be calculated using the method described in the examples.

[0054] The above flame-retardant material can be manufactured by impregnating the above material with an aqueous solution of the present invention and then drying it. The impregnation and drying are not particularly limited and can be carried out by known or conventional methods. The impregnation may be carried out under heating and / or pressurization. The heating temperature is preferably 50°C or higher. The pressurization pressure is usually around 2 to 20 atmospheres. [Examples]

[0055] An embodiment of this disclosure will be described in more detail below based on examples, but the present invention is not limited in any way by these examples. Note that, regarding the content ratios of the various components shown in Table 1, component (A1) is the ratio as B(OH)3, and component (A2) is the ratio as an anhydrous form (Na2B4O7).

[0056] Example 1 In a 2.5 L SUS kettle equipped with a thermometer and a stirrer, 105.35 g of boric acid (B(OH)3, manufactured by Kanto Chemical Co., Ltd.) as component (A1), 131.69 g of borax (Na2B4O7·10H2O, manufactured by Fujifilm Wako Pure Chemical Corporation) as component (A2), 148.52 g of ammonium dihydrogen phosphate (NH4H2PO4, manufactured by Fujifilm Wako Pure Chemical Corporation) as component (B), 99.01 g of diammonium hydrogen phosphate ((NH4)2HPO4, manufactured by Fujifilm Wako Pure Chemical Corporation) as component (B), 75.56 g of guanidine phosphate (guanidine phosphate) ((CH5N3)2·H3PO4, manufactured by Fujifilm Wako Pure Chemical Corporation), and 1439.87 g of pure water were added and stirred at 70°C for 1 hour to completely dissolve the substances, thereby obtaining a mixed aqueous solution of polyborate ions and phosphate (1).

[0057] In calculating the solid content, borax was considered as anhydrous (Na2B4O7), and the solid content was calculated using the following formula.

number

[0058] Examples 2-12 and Comparative Examples 1-2 Mixed aqueous solutions of polyborate ions and phosphates (2) to (14) were obtained in the same manner as in Example 1, except that the proportions of each component were changed as shown in Table 1.

[0059] [Table 1]

[0060] <Rating> The mixed aqueous solutions obtained in the examples and comparative examples were evaluated as follows. The results are shown in Table 2.

[0061] (1) Storage stability test The mixed aqueous solutions prepared in each example were allowed to stand at 23°C and 5°C, respectively, and their condition was visually inspected after 1 day and 7 days. The storage stability of each mixed aqueous solution was then evaluated according to the following criteria. Evaluation at 5°C was performed only if no precipitation occurred after 1 week at 23°C, and evaluation after 1 week was performed only if no precipitation occurred after 1 day at 5°C. ◎: No precipitation after 1 week at 5℃ ○: No precipitation after 1 day at 5℃, precipitation observed after 1 week. △: No precipitation after 1 week at 23℃, precipitation after 1 day at 5℃ ×: Precipitation occurred after 1 week at 23℃.

[0062] (2) Pyrokinetic test (i) Manufacturing of flame-retardant wood material test specimens The mixed aqueous solutions prepared in each example were used as the flame retardant aqueous solution for impregnation. Cedar sapwood measuring 100mm x 100mm x 15mm was used as the wood material. The wood material was pre-dried in a forced-air dryer at 90°C for 24 hours (initial drying). The above wood material was placed in a 3L capacity stainless steel autoclave and subjected to reduced pressure of 5-10 torr for 1 hour at room temperature (20°C). Subsequently, a mixed aqueous solution heated to 60°C was added, and the material was subjected to pressurization at 0.5 MPa (gauge pressure) at 60°C for 1 hour. After pressurization, the obtained wood material was dried for 1 month under conditions of 23°C and 50% RH to obtain flame-retardant wood material test specimens. The mass of the flame-retardant wood material test specimens was measured, and the amount of impregnation was calculated using the following formula.

number

[0063] (ii) Pyrothermal test The exothermic test was performed using each flame-retardant wood material test specimen prepared in (i) above, in accordance with ISO 5660-1, using a cone calorimeter. The total exothermic value was 8 MJ / m³. 2 Based on the time exceeding the specified limit, flame retardancy was evaluated according to the following criteria. 〇: 10 minutes or more △: 5 minutes or more but less than 10 minutes ×: Less than 5 minutes

[0064] (3) Moisture absorption test (i) Resistance to dripping Each flame-retardant wood material test specimen prepared in (2)(i) above was placed in a constant temperature and humidity chamber at 30°C and 90%RH and left to stand for 3 weeks. The surface condition of each flame-retardant wood material test specimen was then visually inspected, and the liquid sagging resistance was determined according to the following criteria. ○: No droplets formed on the surface of the test specimen. △: Droplet formation on the surface of the test specimen. ×: Droplets drip from the surface of the test specimen, creating a puddle at the bottom.

[0065] (ii) Efflorescence resistance Each flame-retardant wood material test specimen that underwent the above liquid sagging resistance evaluation was placed in a forced-air dryer and dried at 60°C for 48 hours. The surface condition of each flame-retardant wood material test specimen after drying was visually inspected, and the efflorescence resistance was determined according to the following criteria. ○: No solid deposits on the surface of the test specimen. ×: Solid deposits were observed on the surface of the test specimen.

[0066] [Table 2]

[0067] As shown in Table 2, the mixed aqueous solutions of the examples were evaluated to be able to impregnate the material with a sufficient amount to impregnate it and impart flame retardancy, and to exhibit excellent resistance to dripping and efflorescence, as well as excellent storage stability of the mixed aqueous solutions. On the other hand, when the elemental ratio (molar ratio) of boron and phosphorus [B / P] was low (Comparative Example 1), resistance to dripping was poor. Also, when component (B) was not included (Comparative Example 2), resistance to efflorescence and storage stability were poor.

[0068] The following describes variations of the invention relating to this disclosure. [Note 1] An aqueous solution of a composition containing the following components (A) and (B), wherein the elemental ratio (molar ratio) of boron and phosphorus [B / P] is 0.33 / 1 to 5.6 / 1. Ingredient (A): Polyborate ions Ingredient (B): Water-soluble phosphate [Note 2] The aqueous solution described in Note 1, wherein component (A) is a polycondensate of a composition containing the following components (A1) and (A2). Component (A1): Boron-containing compound Component (A2): A boron-containing compound different from component (A1) [Note 3] The aqueous solution described in Note 2, wherein component (A1) is boric acid and component (A2) is borax. [Note 4] An aqueous solution described in any one of Notes 1 to 3, having a solid content of 15% by mass or more. [Note 5] The aqueous solution according to any one of Notes 1 to 4, wherein the ratio of component (A) to the total amount of solids is 25 to 85% by mass on an anhydrous basis. [Note 6] The aqueous solution according to any one of Notes 1 to 5, wherein the ratio of component (B) to the total amount of solids is 15 to 75% by mass on an anhydrous basis. [Note 7] The composition is an aqueous solution according to any one of Notes 1 to 6, comprising two or more of the above-mentioned component (B). [Note 8] The aqueous solution according to any one of Notes 1 to 7, wherein component (B) is one or more selected from the group consisting of diammonium hydrogen phosphate, ammonium dihydrogen phosphate, disodium hydrogen phosphate, sodium dihydrogen phosphate, and guanidine phosphate. [Note 9] An aqueous solution described in any one of Notes 1 to 8, having a solid content of 20% by mass or more. [Note 10] An aqueous solution of any one of the following appendices 1 to 9, which is a flame retardant for wood. [Note 11] A flame retardant material comprising a composition containing the following components (A) and (B), wherein the elemental ratio (molar ratio) of boron and phosphorus [B / P] is 0.33 / 1 to 5.6 / 1. Ingredient (A): Polyborate ions Ingredient (B): Water-soluble phosphate [Note 12] A method for producing an aqueous solution of polyborate ions, comprising adding the following components (A1), (A2), and (B) to water, heating and dissolving them to obtain polyborate ions. Component (A1): Boron-containing compound Component (A2): A boron-containing compound different from component (A1) Ingredient (B): Water-soluble phosphate [Note 13] A method for producing the polyborate ion aqueous solution according to Note 12, wherein the heating is performed at a temperature of 60°C or higher.

Claims

1. An aqueous solution of a composition containing the following components (A) and (B), wherein the elemental ratio (molar ratio) of boron and phosphorus [B / P] is 0.33 / 1 to 5.6 / 1. Ingredient (A): Polyborate ions Ingredient (B): Water-soluble phosphate

2. The aqueous solution according to claim 1, wherein component (A) is a polycondensate of a composition containing the following components (A1) and (A2). Ingredient (A1): Boron-containing compound Component (A2): A boron-containing compound different from component (A1)

3. The aqueous solution according to claim 2, wherein component (A1) is boric acid and component (A2) is borax.

4. An aqueous solution according to any one of claims 1 to 3, wherein the solid content is 15% by mass or more.

5. The aqueous solution according to any one of claims 1 to 3, wherein the ratio of component (A) to the total amount of solids is 25 to 85% by mass on an anhydrous basis.

6. The aqueous solution according to any one of claims 1 to 3, wherein the ratio of component (B) to the total amount of solids is 15 to 75% by mass on an anhydrous basis.

7. The aqueous solution according to any one of claims 1 to 3, wherein the composition comprises two or more of the components (B).

8. The aqueous solution according to any one of claims 1 to 3, wherein component (B) is one or more selected from the group consisting of diammonium hydrogen phosphate, ammonium dihydrogen phosphate, disodium hydrogen phosphate, sodium dihydrogen phosphate, and guanidine phosphate.

9. An aqueous solution according to any one of claims 1 to 3, wherein the solid content is 20% by mass or more.

10. An aqueous solution according to any one of claims 1 to 3, which is a flame retardant for wood.

11. A flame retardant material comprising a composition containing the following components (A) and (B), wherein the elemental ratio (molar ratio) of boron and phosphorus [B / P] is 0.33 / 1 to 5.6 / 1. Ingredient (A): Polyborate ions Ingredient (B): Water-soluble phosphate

12. A method for producing an aqueous solution of polyborate ions, comprising adding the following components (A1), (A2), and (B) to water, heating and dissolving them to obtain polyborate ions. Ingredient (A1): Boron-containing compound Component (A2): A boron-containing compound different from component (A1) Ingredient (B): Water-soluble phosphate

13. A method for producing an aqueous polyborate ion solution according to claim 12, wherein the heating is performed at a temperature of 60°C or higher.

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