JP2012121274A - Flame-retardant treatment method for wood material, and woody fire-preventive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flame-retardant treatment method for a wood material capable of inexpensively producing a wood material having fire retardancy and also suppressing an efflorescence phenomenon of its surface.SOLUTION: The method includes: an injection step of injecting the wood material with an acid aqueous solution in which a fire retardant is contained and further a phosphate, a magnesium and an ammonium components, which are not combined and deposited, and are in an ionic state, are present in the solution; and after the injection step, a formation step of bringing the wood material into contact with an alkaline aqueous solution to form a poor solubility substance having phosphate, magnesium and ammonium as principal components on the surface of the wood material and/or inside the wood material. Further, between the injection step and the formation step, it is preferable to include a drying step of drying the surface of the wood material. In the formation step, it is preferable to form the poor solubility substance having phosphate, magnesium and ammonium as the principal components on the surface of the wood material and/or inside the wood material, and also to form an insoluble material of a polymer agent.

Description

  TECHNICAL FIELD The present invention relates to a flame retardant treatment method for wood materials and a wood fire retardant material, and more particularly to a flame retardant treatment method for wood materials and a wood fire retardant material which suppress the surface whiteness phenomenon of wood.

  Wood used as a building material such as an interior material is desired to be a fireproof material exhibiting flame retardancy, quasi-incombustibility, and incombustibility for fire prevention. Therefore, the development of flame retardant treatment technology that makes wood difficult to burn is being carried out.

Performance regulations have been established by amending the Building Standards Law, etc., and wood materials are certified as fireproof materials if they meet the performance standards. One of the methods for evaluating the fireproof performance of a wood material is a heat generation test using a cone calorimeter. In order to satisfy the exothermic test standard of the non-combustible material in this evaluation method, it is necessary to satisfy the following three standards in the heating test for 20 minutes with the irradiation intensity of 50 kW / m ² .
1. The total calorific value is 8 MJ / m ² or less.
2. There should be no cracks or holes penetrating to the back side, which is harmful for fire prevention.
3. The maximum heat generation rate should not exceed 200 kW / m ² for 10 seconds or more.
If these three criteria are satisfied for 10 minutes, the exothermic property of the flame retardant material is cleared if the quasi-incombustible material is satisfied for 5 minutes. In addition to this, it is necessary for the certification as a fire protection material to satisfy the evaluation criteria of the gas hazard test by mice.

  As a processing technology to improve the flame retardancy of wood, a technology that injects non-flammable chemicals such as phosphoric acid, boric acid, and nitrogen into the wood using a pressure injection method or a hot / cold bath method is common. Has been used. As other reforming methods, methods such as a composite with an insoluble noncombustible inorganic material, a composite with a functional resin, and a chemical modification by chemical bonding are used.

  In the composite with the above insoluble and non-combustible inorganic material, for example, two kinds of aqueous solutions separately containing a cation and an anion that react with each other to form an insoluble compound are impregnated into the raw material wood in order to produce an insoluble compound. It is known to fix and modify wood (see, for example, Patent Documents 1 and 2).

  In addition, if the flame retardant is a deliquescent material, the flame retardant may be deposited on the surface and deteriorated when placed under high temperature and humidity conditions. ing. For example, after impregnating a flame retardant, a technique of applying a two-component flame retardant polyurethane resin paint composed of a base material and a curing agent to a wood surface to suppress leaching of the flame retardant is known ( For example, see Patent Document 3). In addition, a technique is disclosed in which an insoluble material is generated on the surface layer of wood, and the top is coated with a synthetic resin such as an epoxy resin (see, for example, Patent Document 4).

Japanese Patent Laid-Open No. 3-112602 JP 61-246003 A JP 2005-271309 A JP 2007-136992 A

  However, in the method for modifying wood described in Patent Documents 1 and 2, since the reaction between the cation-containing compound and the anion-containing compound occurs outside the wood, an insoluble compound is generated in the aqueous solution in the immersion tank, and both water-soluble compositions are formed. There is a problem that chemicals are wasted due to the problem of changing or the reaction outside the wood. Moreover, in patent document 2, if a nonflammable inorganic compound is 40% or more with respect to the absolute dry weight of wood, it is said that a flame retardance cannot be maintained. For this purpose, it is necessary to inject a large amount of a drug, and there is a problem that the processed wood becomes heavy along with the high cost. Further, in the methods described in Patent Documents 3 and 4, a surface whiteness phenomenon may occur under the coating film.

  An object of the present invention is to provide a wood material flame-retarding method and a wood surface which can produce a wood material having flame retardancy and suppressing the surface whiteness phenomenon of wood at low cost. It is to provide a wooden fireproof material that suppresses the white flower phenomenon.

  The present invention includes a flame retardant, and an injection step of injecting an acidic aqueous solution present in the solution in an ionic state without binding and precipitation of phosphoric acid, magnesium and ammonium components into the wood material, and after the injection step, A step of bringing the wood material into contact with an alkaline aqueous solution, and generating a poorly soluble substance mainly composed of magnesium ammonium phosphate on the surface and / or inside of the wood material. This is a flame retardant treatment method.

  In the present invention, the alkaline aqueous solution contains an alkali-soluble polymer agent, and generates a poorly soluble substance mainly composed of magnesium ammonium phosphate on the surface and / or inside of the wooden material in the generation step. It is preferable to form an insolubilized product of the polymer agent.

  Moreover, in this invention, it is preferable to include the drying process which dries the surface of a wooden material further between the said injection | pouring process and the said production | generation process.

  In the present invention, the flame retardant is preferably a water-soluble phosphate.

  In the present invention, ammonium ions contained in the aqueous solution used in the injection step include ammonium dihydrogen phosphate, hydrogen diammonium phosphate, triammonium phosphate, ammonium nitrate, ammonium chloride, ammonium hydrogen carbonate, ammonium fluoride, iodine An ammonium ion obtained by dissolving one or a mixture of two or more of ammonium bromide, ammonium bromide, and ammonium chromate in water can be used.

  In the present invention, magnesium ions contained in the aqueous solution used in the injection step include magnesium hydroxide, magnesium sulfate, magnesium chloride, magnesium bromide, magnesium carbonate, magnesium hydrogen phosphate, magnesium perchlorate, magnesium sulfide, chromium. Magnesium ions obtained by dissolving one kind or a mixture of two or more kinds of magnesium acid in water can be used.

  In the present invention, the alkali-soluble polymer agent is preferably sodium carboxymethyl cellulose and / or sodium polyacrylate.

  Further, in the present invention, an acidic aqueous solution containing the flame retardant and further containing phosphoric acid, magnesium, and ammonium components in an ionic state without binding and precipitation of the phosphoric acid, magnesium, and ammonium components is a water-soluble solution containing phosphoric acid, magnesium, and ammonium components. An aqueous solution in which the flame retardant is dissolved in water is preferable.

  Moreover, in this invention, the phosphate ion, magnesium ion, and ammonium ion contained in the aqueous solution used at the said injection | pouring process are phosphoric acid ion, magnesium ion, and ammonium ion contained in waste water or a waste liquid, and magnesium ammonium phosphate is a main component. It is preferable that the material is recovered as a poorly soluble substance and further ionized under acidic conditions with the poorly soluble substance mainly composed of magnesium ammonium phosphate.

  Moreover, this invention is a wooden fireproofing material characterized by including a flame retardant and the hardly soluble substance which has a magnesium ammonium phosphate as a main component.

  By using the method for flame-retarding a wood material of the present invention, it is possible to produce a wood material having flame retardancy and suppressing the surface whiteness phenomenon of wood at low cost. Moreover, it is possible to obtain a wood fireproofing material having flame retardancy and suppressing the surface whiteness phenomenon of wood.

It is a graph which shows the result of the corn calorimeter test regarding the test body A. FIG. FIG. 6 is a graph showing the results of a corn calorimeter test for test body B. FIG. 5 is a graph showing the results of a corn calorimeter test for test body C. FIG. 5 is a graph showing the results of a corn calorimeter test for test body D. 5 is a graph showing the results of a corn calorimeter test for test body E. FIG. FIG. 5 is a graph showing the results of a corn calorimeter test for test body F. FIG. 6 is a graph showing the results of a corn calorimeter test for test specimen G. FIG. 6 is a graph showing the results of a corn calorimeter test for test body H. It is a graph which shows the result of the corn calorimeter test regarding the test body I. FIG. 6 is a graph showing the results of a corn calorimeter test for test body J. It is a graph which shows the result of the corn calorimeter test regarding the test body K. FIG. FIG. 5 is a graph showing the results of a corn calorimeter test for a test specimen L. FIG. 6 is a graph showing the results of a corn calorimeter test for a test specimen M. FIG. 5 is a graph showing the results of a corn calorimeter test for a specimen N. It is an experimental result of Example 1 and Comparative Examples 1 and 2, and is a diagram showing a relationship between a drug injection amount and a total calorific value. FIG. 6 is a graph showing the results of a corn calorimeter test relating to a specimen O. It is a graph which shows the result of the cone calorimeter test regarding the test body P. FIG. It is a graph which shows the result of the corn calorimeter test regarding the test body Q. FIG. It is a graph which shows the result of the corn calorimeter test regarding the test body R. FIG. It is a graph which shows the result of the corn calorimeter test regarding the test body S. FIG. FIG. 6 is a graph showing the results of a corn calorimeter test for a test specimen T. FIG. 6 is a graph showing the results of a corn calorimeter test relating to a specimen U. FIG. 5 is a graph showing the results of a corn calorimeter test for a specimen V. It is a graph which shows the result of the cone calorimeter test regarding the test body W. FIG. FIG. 5 is a graph showing the results of a corn calorimeter test for test body X. It is a graph which shows the result of the corn calorimeter test regarding the test body Y. FIG. FIG. 6 is a graph showing the results of a corn calorimeter test for a specimen Z. It is a graph which shows the result of the corn calorimeter test regarding test body AA. It is a graph which shows the result of the corn calorimeter test regarding test body AB. It is a graph which shows the result of the cone calorimeter test regarding test body AC. It is a graph which shows the result of the cone calorimeter test regarding test body AD. It is a graph which shows the result of the corn calorimeter test regarding test body AE. It is an experimental result of Examples 2-4 and the comparative example 3, and is a figure which shows the relationship between a chemical injection amount and a total calorific value.

  It is known that phosphate drugs are generally soluble in water and exhibit deliquescence. When such a deliquescent flame retardant is injected into the interior of a wood material, the surface of the leaching etc. where the flame retardant absorbs moisture in the atmosphere and the molten wood dissolves on the surface of the wood when the injected wood is placed under high temperature and humidity conditions. Deterioration occurs. In order to solve this problem, in the flame retardant treatment method for woody material of the present invention, magnesium ammonium phosphate is a poorly water-soluble substance, and magnesium ammonium phosphate is an acid containing phosphate ions, magnesium ions, and ammonium ions. It is utilized that it can be precipitated by changing the aqueous solution of this to alkaline. In general, a flame retardant is injected into a wood material, the surface of the wood material is covered with a poorly soluble substance mainly composed of magnesium ammonium phosphate, and / or the interior of the wood material is composed mainly of magnesium ammonium phosphate. This produces a hardly soluble material that suppresses leaching of the flame retardant. Hereinafter, the flame retardant treatment method for a woody material of the present invention will be described in detail.

  The flame-retardant treatment method for a wood material according to the present invention includes a flame retardant, and further injects into the wood material an acidic aqueous solution that is present in the solution in an ionic state without binding and precipitation of phosphoric acid, magnesium, and ammonium components. An injection process and the production | generation process which makes a wooden material contact with alkaline aqueous solution after an injection | pouring process, and produces | generates the hardly soluble substance which has a magnesium ammonium phosphate as a main component on the surface and / or inside of a wooden material are included.

  The wood material to which the flame retardant treatment method for wood material of the present invention can be applied is not particularly limited and can be widely applied to wood materials. For example, natural wood, processed wood, laminated timber, plywood, LVL, and the like are exemplified by pine, cedar, firewood, beech, radiata pine, and the like.

  In the injection step, an acidic aqueous solution containing a flame retardant and further present in the solution in an ionic state without binding and precipitation of phosphoric acid, magnesium and ammonium components is used. Here, a flame retardant is contained, and an acidic aqueous solution in which the phosphoric acid, magnesium and ammonium components are not bound and precipitated in an ionic state in the solution is different from the flame retardant and phosphoric acid, magnesium and ammonium components. Of course, it includes the case where the flame retardant containing phosphoric acid, magnesium and ammonium components is completely dissolved to form an ionic phosphoric acid, magnesium and ammonium component.

  The flame retardant usable here is not limited to a specific flame retardant, and a known water-soluble flame retardant can be used. Examples of such flame retardants include phosphoric acids such as ammonium dihydrogen phosphate and diammonium hydrogen phosphate, boric acids such as boric acid, borax, and zinc borate, and nitrogen-based flame retardants such as melamine and ammonium. Is exemplified. However, flame retardants that exhibit alkalinity when dissolved in water are not preferred.

  In the injection step, an aqueous solution containing a flame retardant is used. At the same time, phosphoric acid, magnesium, and ammonium components, which are components of a hardly soluble substance mainly composed of magnesium ammonium phosphate, generated in the next generation step, are used. Use aqueous solution containing in ionic state. The phosphoric acid, magnesium, and ammonium components can exist stably in an ionic state under acidic conditions, but when alkaline, they become magnesium ammonium phosphate and precipitate. Since the production | generation of the hardly soluble substance which has magnesium ammonium phosphate as a main component needs to produce | generate after inject | pouring a flame retardant into a wooden material, it is necessary to make aqueous solution an acidic state in an injection | pouring process.

  Since the aqueous solution used in the injection process needs to contain phosphoric acid, magnesium, and ammonium components in an ionic state in addition to the flame retardant as described above, a water-soluble phosphoric acid system is required for the flame retardant. If this flame retardant is used, there is no need to separately add a phosphoric acid component, which is efficient. Of course, the flame retardant may contain all of phosphoric acid, magnesium and ammonium components, and the phosphoric acid, magnesium and ammonium components may be provided from the flame retardant. The aqueous solution containing ammonium dihydrogen phosphate and magnesium sulfate shown in the examples described later is acidic. In this case, ammonium dihydrogen phosphate and magnesium sulfate function as a flame retardant, and phosphoric acid, magnesium and ammonium components are added. provide. Even in such a case, it is not necessary to separately add phosphoric acid, magnesium and ammonium components, which is efficient.

  Phosphate ions are phosphoric acid, sodium dihydrogen phosphate, disodium hydrogen phosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, tripotassium phosphate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, phosphorus It can be obtained by dissolving one or a mixture of two or more of triammonium acid, magnesium hydrogen phosphate, and guanidine phosphate in water.

  The ammonium ion is one kind of ammonium dihydrogen phosphate, diammonium hydrogen phosphate, triammonium phosphate, ammonium nitrate, ammonium chloride, ammonium hydrogen carbonate, ammonium fluoride, ammonium iodide, ammonium bromide, ammonium chromate or It can be obtained by dissolving two or more mixtures in water.

  Magnesium ion is one or a mixture of two or more of magnesium hydroxide, magnesium sulfate, magnesium chloride, magnesium bromide, magnesium carbonate, magnesium hydrogen phosphate, magnesium perchlorate, magnesium sulfide, and magnesium chromate in water. It can be obtained by dissolving.

  Furthermore, the phosphoric acid, magnesium, and ammonium components in an ionic state can be obtained in the following manner. When phosphoric acid, magnesium, and ammonium components are contained in the effluent or waste liquid in an ionic state, a hardly soluble substance containing magnesium ammonium phosphate as a main component is precipitated when this is alkalinized. This waste water or waste liquid is filtered to recover a hardly soluble substance mainly composed of magnesium ammonium phosphate. When this hardly soluble substance is put into an acidic aqueous solution, the hardly soluble substance is dissolved, and the phosphoric acid, magnesium and ammonium components are dissolved. It becomes an ionic state. In this way, by utilizing the change in pH, phosphoric acid, magnesium, and ammonium components with high purity can be recovered from waste water or waste liquid. This method can be said to be a preferable method that reduces the load of wastewater or waste liquid treatment, including cost merit.

  The method of injecting the aqueous solution into the wood material is not limited to a specific method, and a known method can be used. Specifically, a method of immersing a wooden material in an aqueous solution, a method of applying an aqueous solution, a pressure injection method, a reduced pressure injection method, a hot / cold bath method, or the like can be used. In particular, a pressure injection method that can increase the injection amount within a short time can be suitably used.

What is necessary is just to determine suitably the quantity of the aqueous solution or flame retardant inject | poured at an injection | pouring process according to the kind of flame retardant to be used, and the use of the wood material which carried out the flame retardant treatment. One example of a drug infusion volume is woody material 1 m ³ per 100~160kg about as described in the Examples below. The chemical concentration of the aqueous solution is preferably 10 wt% to 70 wt% so that the viscosity does not become too high. When the semi-incombustible material is used, the drug injection amount is about 100 to 160 kg per 1 m ³ of the wood material. However, when the non-combustible material is targeted, the drug injection amount is about 190 kg per 1 m ³ of the wood material. The above injection amount is required.

  The generation step is a step performed after the injection step, and the wooden material after the chemical injection is brought into contact with an alkaline aqueous solution to generate a hardly soluble substance mainly composed of magnesium ammonium phosphate on the surface and / or inside of the wooden material. . In addition to the flame retardant, the woody material after the injection step contains ionic phosphoric acid, magnesium and ammonium components. When such a wooden material is brought into contact with an alkaline aqueous solution, the surface of the wooden material injected in the injection step or the aqueous solution inside the wooden material comes into contact with the alkaline aqueous solution and changes from acidic to alkaline. Along with this, phosphoric acid, magnesium and ammonium components in an ionic state react, and a hardly soluble substance containing magnesium ammonium phosphate as a main component is deposited on the surface of the wooden material and / or inside the wooden material. In addition, it becomes a hardly soluble substance containing magnesium phosphate and magnesium hydroxide by the ratio of phosphate ion, magnesium ion, ammonium ion and the strength of the alkaline solution.

  Magnesium ammonium phosphate is sparingly water-soluble, so it does not dissolve easily even when it comes into contact with water, and the surface of the woody material is covered with a sparingly soluble substance mainly composed of magnesium ammonium phosphate and / or woody. By closing the pores of the material with a poorly soluble substance mainly composed of magnesium ammonium phosphate, the opportunity for the flame retardant in the pores to come into contact with water is reduced, and leaching is suppressed. Since the hardly soluble substance is generated to suppress the leaching of the flame retardant injected into the wooden material, the hardly soluble substance generated inside the wooden material can be blocked by closing the vicinity of the pore entrance of the wooden material. Well, it is not always necessary to generate a hardly soluble substance deep in the pores. Even if the flame retardant contains all phosphoric acid, magnesium, and ammonium components, and phosphoric acid, magnesium, and ammonium components are provided from the flame retardant, it is not necessary to add all of the phosphoric acid, magnesium, and ammonium components to magnesium ammonium phosphate. It is not necessary to use a hardly soluble substance as a main component, as long as it covers the surface of the wood material and / or closes the pores of the wood material and suppresses the leaching of the flame retardant remaining in the pores.

  The alkaline aqueous solution used here is not particularly limited, and a known alkaline aqueous solution such as a sodium hydroxide aqueous solution can be used. The alkaline aqueous solution may be about 8 to 13 in pH.

  The contact between the woody material and the alkaline aqueous solution in the production step is not limited to a specific method. For example, the woody material after the injection of the drug may be immersed in the alkaline aqueous solution. When the wood material is immersed in an alkaline aqueous solution, a poorly soluble substance mainly composed of magnesium ammonium phosphate may be precipitated in the aqueous solution. In this case, the hardly soluble substance is recovered by filtration or the like, If this is put into an acidic aqueous solution, it returns to an ionic state, so that waste of chemicals can be prevented by using this method.

  The flame retardant treatment method of the wood material of the present invention is a method of covering the surface of the wood material with a hardly soluble substance and / or closing the pores of the wood material with the hardly soluble substance after injecting the flame retardant into the wood material. For example, it can be said that the method is similar to the technique described in JP-A-3-112602. However, this method is very different from the conventional method in terms of operational effects. In the flame retardant treatment method for woody materials of the present invention, all components necessary for the production of the hardly soluble substance are injected in the injection step, and the pH of the aqueous solution is merely changed in the generation step. For this reason, the component composition required for the production | generation of a hardly soluble substance is constant, and a hardly soluble substance can be produced | generated stably. On the other hand, in a method in which a solution containing an anion or a cation is injected into a wood material in advance and then the wood material is brought into contact with a solution containing a cation or an anion, the anion contains a solution depending on the contact state between the solution containing an anion and the solution containing a cation. The ratio of cation to cation is different, and a hardly soluble substance cannot be stably generated. In the generation of unstable hardly soluble substances, the surface of the wood material and / or the inside of the wood material is likely to have a portion where the hardly soluble substance does not exist, and as a result, the leaching suppression of the flame retardant injected into the wood material is insufficient. Thus, the surface whiteness phenomenon tends to occur.

  The wood material flame retardant treatment method of the present invention comprises an injection step and a production step, whereby a wood material having flame retardancy and further suppressing surface whiteness can be obtained. It is preferable to further include a drying step for drying the wood material between the generation steps. The poorly soluble substance mainly composed of magnesium ammonium phosphate produced in the production step is preferably produced in the pore entrance portion of the wood material, and further in the interior, considering separation from the wood material. By forming a poorly soluble substance in the pore entrance portion of the wood material, and further inside, an improvement in adhesion to the wood material can be expected due to the anchor effect. By drying the wood material after the injection process, an alkaline aqueous solution enters the pores of the wood material in the production process, increasing the production of poorly soluble substances in the pore entrance portion of the wood material, and further inside. I can expect. In addition, by forming a hardly soluble substance in the pore entrance portion of the wood material, and further inside, the precipitation of the hardly soluble substance in the aqueous solution in the production step is reduced, which is preferable from the viewpoint of cost.

  As described above, the drying process is for generating a poorly soluble substance in the pore entrance portion of the wood material, and further inside, and drying the surface of the wood material to the limit where the injected drug does not occur. Is preferred. The drying method is not particularly limited, but may be natural drying.

  As described above, by placing a drying step between the injection step and the generation step, and further between the injection step and the generation step, it is possible to obtain a wood material having flame retardancy and further suppressing the surface whiteness phenomenon, In order to suppress the surface whiteness phenomenon over a long period of time, it is desirable to more surely suppress the separation of the hardly soluble substance mainly composed of magnesium ammonium phosphate. As a method for realizing this, a hardly soluble substance mainly composed of magnesium ammonium phosphate is deposited, and at the same time, the surface of the wood material and / or the inside of the wood material is coated with an insolubilized material of a polymer agent. The coating with the insolubilized material inside the wood material may be in the vicinity of the pore entrance.

  Here, a polymer agent that becomes insoluble with changes in pH is used. Specifically, an aqueous solution in which a polymer agent that dissolves in an alkaline aqueous solution is added to the alkaline aqueous solution used in the production step is used. When such an aqueous solution is brought into contact with the wood material after the pouring step, a poorly soluble substance mainly composed of magnesium ammonium phosphate is formed on the surface of the wood material and / or inside the wood material, and the polymer agent is made of the wood material. It comes into contact with the acidic aqueous solution injected into the solution and becomes insoluble and precipitates due to a change in pH.

  Examples of the polymer agent that dissolves in an alkaline aqueous solution and gels and precipitates in an acidic state include sodium polyacrylate and sodium carboxymethylcellulose. It is known that sodium polyacrylate and sodium carboxymethylcellulose are gelated by kneading with an acid. In addition, sodium polyacrylate and sodium carboxymethylcellulose are combined with polyvalent metal ions in an aqueous solution to be converted into an insoluble gel. Therefore, if such a polymer agent is used, it can be easily gelled and precipitated in the production process, and the surface of the wood material can be covered.

  The coating with the insolubilized material such as the surface of the wood material is performed in order to suppress the separation of the hardly soluble substance mainly composed of magnesium ammonium phosphate, and other coating methods can be considered. The method is preferred. In the above method, an insolubilized material is generated together with a hardly soluble substance mainly composed of magnesium ammonium phosphate in the generating step, and the surface of the wooden material and / or the inside of the wooden material is coated with the insolubilized material of the polymer agent. Therefore, it is not necessary to separately perform an operation for coating with the insolubilized material, and it can be performed easily and inexpensively. In addition, since the generation of the hardly soluble substance mainly composed of magnesium ammonium phosphate and the coating with the insolubilized substance of the polymer agent are simultaneously performed, the hardly soluble substance mainly composed of magnesium ammonium phosphate and the insolubilized substance of the polymer agent Are integrated, and the separation of the hardly soluble substance can be reliably suppressed. Even in this case, the drying step is performed in order to form insolubilized material in the pore entrance portion of the wood material, and further in the interior, and to reduce the precipitation of the hardly soluble substance in the aqueous solution in the production step. Then, it is preferable to perform the generation step thereafter.

  Sodium polyacrylate and sodium carboxymethylcellulose are easily available and relatively inexpensive drugs, and are preferable as a polymer agent for coating the surface of the wood material and / or the inside of the wood material. Moreover, since sodium polyacrylate and sodium carboxymethylcellulose have hygroscopicity, they absorb moisture in the air. As a result, contact of the flame retardant with moisture can be more reliably prevented. In addition, when it is a case where it uses under high-humidity conditions and worries about stickiness, what is necessary is just to apply | coat a well-known coating material on the surface of a wooden material.

  As described above, the use of the flame retardant treatment method for a woody material according to the present invention enables the flame retardant treatment with suppressed surface deposition of the drug. The flame-retardant wood material produced in this way has a flame retardance equivalent to that of a wood material into which a commonly used phosphoric acid chemical is injected. In addition, it is possible to generate a poorly soluble substance mainly composed of magnesium ammonium phosphate in the wood material, and to simultaneously cover the surface with the insolubilized polymer agent in one step, so that the wood A wood fireproof material that does not deteriorate the surface of the material can be manufactured at low cost. Further, it is possible to improve the water resistance and scratch resistance by repeatedly applying a hydrophobic paint. It is known that chemical precipitation may occur under the surface film when surface coating is applied to wood that has been subjected to chemical injection treatment, but when using the method for flame-retardant treatment of woody material of the present invention, As shown in the Examples, almost no chemical precipitation occurred under the surface coating film.

  Next, examples of the present invention will be described, but the present invention is not limited to the examples.

Example 1
An aqueous solution in which 180 g / L of ammonium dihydrogen phosphate and 20 g / L of magnesium sulfate were dissolved was prepared. This aqueous solution was poured into an air-dried cedar board (11 cm × 32 cm × 18 mm) using a vacuum pressurizer. Four cedar boards were prepared and the following treatment was performed simultaneously. In order to approach the injection amount when an experiment was conducted with a long plate material, the side surface in the fiber direction was coated with a hydrophobic silicone resin. The injection was performed in the order of reduced pressure for 5 minutes, increased pressure for 15 to 60 minutes, and reduced pressure for 5 minutes. The reduced pressure was -660 mmHg and the pressure was about 10 kgf / cm ² (both gauge pressures) (injection step). The solution injection amount was about 500 to 820 kg / m ³ . After the drug injection, the wood surface was dried at room temperature for 3 days (drying process). After drying, sodium hydroxide was dissolved to adjust the pH to about 12 and immersed in an aqueous solution in which 7.0 g / L of sodium carboxymethylcellulose was dissolved for 5 minutes to generate a hardly water-soluble substance-containing gel on the wood surface layer (generation) Process).
Evaluation method: Thereafter, the sample was dried in a room for about one month, cut into 10 cm × 10 cm × 18 mm test pieces, and subjected to a cone calorimeter (exothermic property) test. The cone calorimeter test was performed in accordance with ISO5660-1. The surface whiteness phenomenon was evaluated visually.

Comparative Example 1
The aqueous solution was injected and dried in the same manner as in Example 1. However, contact with an alkaline aqueous solution was not performed. Evaluation was performed in the same manner as in Example 1.

Comparative Example 2
In the same manner as in Example 1, an aqueous solution in which 200 g / L of ammonium dihydrogen phosphate was dissolved was injected and then dried. No contact with the alkaline aqueous solution was performed. Evaluation was performed in the same manner as in Example 1.

  The result of the cone calorimeter test of each test body is shown in FIGS. The evaluation results are shown in Table 1 and FIG. The total calorific value shown in FIG. 15 is the total calorific value for 10 minutes. The substance (drug) injection amount was determined by multiplying the solution injection amount and the weight concentration of the solution.

Flame retardant results (Example 1, Comparative Examples 1 and 2)
In both Example 1 and Comparative Examples 1 and 2, the total calorific value was inversely proportional to the drug injection amount. After injecting an aqueous solution of ammonium dihydrogen phosphate: magnesium sulfate = 9: 1 (20 wt%), the pH was adjusted to about 12, and wood immersed in 7.0 g / L aqueous solution of sodium carboxymethyl cellulose for 5 minutes ( In the case of Example 1), the total calorific value at a heating time of 10 minutes was about 5 MJ / m ² at a drug injection amount of 120 kg / m ³ . Comparing the total calorific value of Example 1 and Comparative Examples 1 and 2, the total calorific value of Example 1 was slightly higher, but it can be said that the flame retardancy is comparable. Even when about 10% of ammonium dihydrogen phosphate was replaced with magnesium sulfate and immersed in an aqueous sodium carboxymethyl cellulose solution for 5 minutes, the total calorific value did not increase significantly.
Results of surface whiteness phenomenon (Example 1, Comparative Examples 1 and 2)
In the test body of Example 1, almost no surface whiteness phenomenon was observed. On the other hand, the test samples of Comparative Examples 1 and 2 showed a surface whiteness phenomenon in all the test samples.

Example 2
A test specimen was produced in the same manner as in Example 1 except that an aqueous solution of ammonium dihydrogen phosphate: magnesium sulfate = 5: 5 (20 wt%) was used as the aqueous solution in the injection step.

Examples 3 and 4
A test specimen was manufactured in the same manner as in Example 2, except that the dipping time in the generating step was 2 hours (Example 3) and 24 hours (Example 4).

Comparative Example 3
A test specimen was manufactured in the same manner as in Comparative Example 1 except that an aqueous solution of ammonium dihydrogen phosphate: magnesium sulfate = 5: 5 (20 wt%) was used as the aqueous solution in the injection step.

  The result of the corn calorimeter test of each test body is shown in FIGS. The evaluation results are shown in Table 2 and FIG. The total calorific value shown in FIG. 33 is the total calorific value for 10 minutes. The substance (drug) injection amount was determined by multiplying the solution injection amount and the weight concentration of the solution.

Flame retardant results (Examples 2, 3, 4, Comparative Example 3)
Compared with the total calorific value of the specimens of Examples 2 to 4 and Comparative Example 3, the total calorific value of the specimens of Comparative Example 2 was clearly increased. Further, as the immersion time in the production process was increased, the total calorific value was increased in the cone calorimeter test. There was no significant difference in the total calorific value between the test body (Example 2) in which the dipping time of the generation process was 5 minutes and the test body (Comparative Example 3) where the generation process was not performed. Here, we examined the method by replacing ammonium dihydrogen phosphate with magnesium sulfate, but considering that magnesium sulfate was added to the ammonium dihydrogen phosphate aqueous solution, the same amount of dihydrogen phosphate was found from the results of the exothermic test. There is a slight increase in flame retardancy compared to the aqueous ammonium solution.
Results of surface whiteness phenomenon (Examples 2, 3, 4, Comparative Example 3)
No white flower was observed on the surface of the test specimens of Examples 2 to 4, and the surface white flower was suppressed more than the test specimen of Example 1. On the other hand, in the test body of Comparative Example 3, surface whiteness was observed in all the test bodies.

A test body was prepared in the same manner as in Example 1 except that an aqueous solution adjusted to a pH of about 12 was used as the aqueous solution used in the production step. The amount of solution injected at this time was about 650 kg / m ³ (Example 5). Similarly, the test body was manufactured using the aqueous solution which adjusted pH to about 12 and dissolved sodium polyacrylate 250g / L in the aqueous solution used at a production | generation process (Example 6). The specimen manufactured by the same method as in Example 1 and the specimens manufactured in Example 5 and Example 6 were dried in a room for about two months, and the surface whiteness phenomenon was observed. For comparison, test specimens manufactured by the same method as in Comparative Example 1 and Comparative Example 2 were also dried in a room for about two months, and the surface whiteness phenomenon was observed.

  In the specimens of Example 1, Example 5 and Example 6, no surface whiteness phenomenon was observed. On the other hand, the surface whiteness phenomenon was observed in the specimens manufactured by the same method as in Comparative Example 1 and Comparative Example 2.

  Test specimens produced in the same manner as in Example 1, Example 5 and Example 6, and specimens produced in the same manner as in Comparative Example 1 and Comparative Example 2 were dried indoors for about 1 month for surface whiteness phenomenon. A specimen was obtained. Thereafter, repeated wet and dry tests using a thermo-hygrostat were performed to observe the surface whiteness phenomenon. The dry / wet repetition test using a thermo-hygrostat was performed for 5 cycles with a cycle of “wet condition” of 40 ° C.-90% RH and “dry condition” of 40 ° C.-35% RH for 24 hours.

  As a result of the experiment, the specimens manufactured by the same method as in Example 1 and Example 6 had stickiness on the surface, but almost no surface whiteness phenomenon was observed. Even in the specimen prepared by the method of Example 5, almost no surface whiteness phenomenon was observed. On the other hand, the surface whiteness phenomenon was seen in the test bodies obtained by the same method as in Comparative Example 1 and Comparative Example 2.

  Test specimens produced in the same manner as in Example 1 and Example 6 were dried in a room for about 1 month, and oil-based urethane varnish was coated on the surface. Although it was left in the room for 2 months after coating, no chemical deposition was observed under the surface coating film. After that, repeated wet and dry tests using a thermo-hygrostat were performed to observe the surface whiteness phenomenon. The dry / wet repetition test using a thermo-hygrostat was performed for 5 cycles with a cycle of “wet condition” of 40 ° C.-90% RH and “dry condition” of 40 ° C.-35% RH for 24 hours. After the test, the surface was observed, but no chemical deposition under the coating film could be confirmed.

Claims (10)

An injection process that injects into the wood material an acidic aqueous solution that contains a flame retardant, and in which the phosphoric acid, magnesium, and ammonium components are not bound and precipitated and exist in the solution in an ionic state;
After the injecting step, the wooden material is brought into contact with an alkaline aqueous solution, and a generating step of generating a hardly soluble substance mainly composed of magnesium ammonium phosphate on the surface and / or inside of the wooden material;
A flame retardant treatment method for a wood material, comprising: The alkaline aqueous solution contains an alkali-soluble polymer agent,
The said production | generation process WHEREIN: The insoluble matter of the said polymeric agent is produced | generated while producing | generating the sparingly soluble substance which has a magnesium ammonium phosphate as a main component on the surface and / or inside of the said wood material. A method for flame-retarding wood materials as described.   The wood material flame-retardant treatment method according to claim 1, further comprising a drying step of drying a surface of the wood material between the injection step and the generation step.   The flame retardant treatment method for a woody material according to any one of claims 1 to 3, wherein the flame retardant is a water-soluble phosphate.   Ammonium ions contained in the aqueous solution used in the injection step are ammonium dihydrogen phosphate, diammonium hydrogen phosphate, triammonium phosphate, ammonium nitrate, ammonium chloride, ammonium bicarbonate, ammonium fluoride, ammonium iodide, bromide. The flame retardant of a woody material according to any one of claims 1 to 4, which is an ammonium ion obtained by dissolving one or a mixture of two or more of ammonium and ammonium chromate in water. Processing method.   Magnesium ions contained in the aqueous solution used in the injection step are one of magnesium hydroxide, magnesium sulfate, magnesium chloride, magnesium bromide, magnesium carbonate, magnesium hydrogen phosphate, magnesium perchlorate, magnesium sulfide, and magnesium chromate. The method for flame-retarding a woody material according to any one of claims 1 to 5, which is magnesium ion obtained by dissolving a seed or a mixture of two or more kinds in water.   The method for flame-retarding a woody material according to any one of claims 3 to 6, wherein the alkali-soluble polymer agent is sodium carboxymethyl cellulose and / or sodium polyacrylate.   An acidic aqueous solution containing the flame retardant and further containing phosphoric acid, magnesium, and ammonium components in an ionic state without binding or precipitating phosphoric acid, magnesium, and ammonium components is water-soluble flame retardant containing phosphoric acid, magnesium, and ammonium components. The method for flame retardant treatment of a woody material according to any one of claims 1 to 3, wherein the method is an aqueous solution dissolved in the water.   Phosphate ions, magnesium ions, and ammonium ions contained in the aqueous solution used in the injecting step are phosphoric acid ions, magnesium ions, and ammonium ions contained in the waste water or waste liquid as hardly soluble substances mainly composed of magnesium ammonium phosphate. The flame-retardant material for wood according to any one of claims 1 to 3, wherein the wood-based material is recovered and further obtained by ionizing a poorly soluble substance mainly composed of magnesium ammonium phosphate under acidic conditions. Processing method.   A wood fireproofing material characterized by comprising a flame retardant and a hardly soluble substance mainly composed of magnesium ammonium phosphate.

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