Method for producing modified wood material, 5-HMF resinification solution, and modified wood material

Abstract

The invention discloses a manufacturing method of a modified wood material. Specifically disclosed is a method for producing a modified wood material, which comprises: 1) a step for infiltrating a 5-HMF resinification solution, which contains 5-hydroxymethylfurfural (5-HMF) and an inorganic salt that promotes the polymerization of 5-HMF, into a wood material; and 2) a step in which the 5-HMF of the permeated 5-HMF resinification solution is polymerized in the wood material by heating.

Description

Technical Field

[0001] The present invention relates to a method for modifying a wood material, that is, a method for producing a modified wood material (modified wood material). In addition, the present invention also relates to a solution used in the production method and a wood material modified by treatment using the solution. Background Art

[0002] As wood materials, there are, for example, broadleaf wood and coniferous wood. For example, tropical broadleaf wood is generally hard and resistant to decay, and therefore is used for interior materials such as wooden floors, exterior building materials (exterior materials) such as wooden decks, etc., in addition to furniture.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application No. 2005-533688 Summary of the invention

[0006] In order to make the wood material more suitable for use, it is considered to modify the wood material.

[0007] The object of the present invention is to modify wood materials.

[0008] The present inventors have conducted intensive studies based on the above problems and have found that a furan derivative resin solution such as a 5-HMF resin solution composed of a furan derivative represented by 5-HMF and a specific agent that promotes polymerization of at least a part of the furan derivative and / or adhesion to a wood material can be used as a solution for modifying a wood material, thereby imparting desired properties to the wood material, thereby completing the present invention.

[0009] The present invention provides a manufacturing method, which is a manufacturing method of a modified wood material, comprising the following steps:

[0010] 1) a step of infiltrating a furan derivative resin solution such as a 5-HMF resin solution into a wood material, wherein the furan derivative resin solution such as the 5-HMF resin solution contains a furan derivative represented by 5-HMF and an agent that promotes polymerization of at least a part of the furan derivative and / or adhesion to the wood material, such as an inorganic salt and / or a hydrate or anhydride thereof, and / or an organic acid and / or a hydrate, anhydride and / or a salt thereof; and

[0011] 2) A step of polymerizing at least a portion of the furan derivative in the infiltrated 5-HMF resinization solution or other furan derivative resinization solution in the wood material and / or causing it to adhere to the wood material.

[0012] In addition, the present invention also provides a furan derivative resin solution such as a 5-HMF resin solution suitable for use in the above-mentioned production method. Specifically, the present invention provides a furan derivative resin solution such as a 5-HMF resin solution, which is a solution for modifying wood materials.

[0013] The furan derivative resin solution such as the 5-HMF resin solution contains a furan derivative represented by 5-HMF, and an agent that promotes polymerization of at least a part of the furan derivative such as 5-HMF and / or adhesion to a wood material, such as an inorganic salt and / or a hydrate or anhydride thereof, and / or an organic acid and / or a hydrate, anhydride and / or a salt thereof.

[0014] In addition, the present invention provides a modified wood material obtained by the above production method. Specifically, the present invention provides a modified wood material, which is a wood material modified by the above production method, and contains at least polymerized and / or attached furan derivatives such as 5-HMF.

[0015] According to the invention, wood materials may be modified.

[0016] More specifically, the furan derivative resin solution such as 5-HMF resin solution used for modification can impart at least one property selected from the group consisting of better anti-swelling ability (ASE) and flexural strength, compressive strength and hardness to the wood material by modifying the wood material using the solution. DETAILED DESCRIPTION

[0017] Hereinafter, one embodiment of the present invention will be described in more detail.

[0018] As for various numerical values ​​and their ranges mentioned in this specification, unless there is a special term such as "less than", "more than / greater than", it means that the numerical value itself as the lower limit or upper limit is included. That is, for example, if it is a numerical range of 1 to 10, it can be interpreted as including the lower limit "1" and the upper limit "10".

[0019] [Views etc. as the basis of this disclosure]

[0020] In recent years, depletion of trees, such as tropical broadleaf trees, has been recognized as a problem due to overharvesting.

[0021] On the other hand, as the stock of Japanese conifers increases, there is a demand to develop new uses for Japanese conifers and seek added value. However, when using Japanese conifers as a substitute for tropical broadleaf timber, it is necessary to pay attention to at least one of the following matters. For example, when using conifers as a substitute for broadleaf timber, it is necessary to improve durability (for example, resistance to wood decay fungi, etc.) and hardness.

[0022] In addition, there are also problems when using durable and hard broadleaved wood as exterior building materials for residential buildings such as wooden decks. That is, wood, especially high-density and hard wood, has large dimensional changes with changes in moisture content, which often results in bending and cracking. Therefore, in order to suppress this situation, it is necessary to adopt measures such as strong connection with thick bolts, and its construction is very laborious. In addition, such thick bolts often loosen due to the force that deforms the wood. For wooden materials used as exterior building materials for residential buildings such as wooden decks, good durability is required, and small dimensional changes with changes in moisture content (i.e. high dimensional stability) are also required. In addition, hardness is also required from the perspective of not being easy to crack or damage.

[0023] In the technology described in Japanese Patent Application Publication No. 2005-533688 (Patent Document 1), acetone and low-boiling alcohol are used as solubilizers. In a furan derivative monomer solution to which such a solubilizer is added, it is difficult to say that the polymerization of the furan derivative can be fully suppressed, at least during the storage period at room temperature. If the furan derivative is polymerized and polymerized during the storage period, that is, before penetrating into the wood material, it is difficult to penetrate into the wood material more evenly. Therefore, it can be said that such a technology makes it difficult for the furan derivative to fully penetrate into the wood material (for example, wood materials of Japanese conifers such as Japanese cedar and cypress). In addition, even if it penetrates, it is difficult to achieve satisfactory modification of the wood material.

[0024] In view of the above background, the present applicants and others applied for an invention related to a method for producing a wood material modified with a furan derivative (International Patent Application PCT / JP2021 / 027813).

[0025] In the invention related to the prior application, a stabilizer is required to stabilize furfuryl alcohol, which is a furan derivative, in an aqueous solution. In addition, in the heating process of polymerization, since the low-boiling-point furan derivative monomer evaporates and disperses from the wood, the yield decreases, so it is necessary to go through the following two-stage heating process: first, the furan derivative monomer that has penetrated into the wood material is heated at a relatively low temperature to allow the polymerization to proceed to a certain extent while suppressing evaporation, and then heated to a high temperature to complete the polymerization.

[0026] In the present disclosure, in addition to the matters solved by the present applicants and others in the prior application, there is an attempt to solve the problem that a stabilizer needs to be added in the invention related to the prior application and that a two-step heating process is required for the resinification of a furan derivative of a wood material by using 5-HMF and / or its derivatives, which is a type of furan derivative.

[0027] [Production method of the present invention]

[0028] The present invention provides a method for producing a modified wood material. That is, the present invention provides a method for producing a modified wood material as a method for modifying a wood material.

[0029] The manufacturing method of the present invention comprises the following steps:

[0030] 1) a step of allowing a furan derivative resin solution to penetrate into a wood material, wherein the furan derivative resin solution contains a furan derivative and an agent that promotes polymerization of at least a portion of the furan derivative and / or adhesion to the wood material, such as an inorganic salt and / or a hydrate or anhydride thereof, and / or an organic acid and / or a hydrate, anhydride and / or salt thereof; and

[0031] 2) A step of polymerizing at least a portion of the furan derivative in the infiltrated furan derivative resinification solution in the wood material and / or causing it to adhere to the wood material.

[0032] In the present disclosure, "furan derivative resin solution" mainly refers to a liquid used in a process in which a resin is contained in at least a part of a wood material by polymerization of a furan derivative. That is, "resinization" in the present specification essentially refers to the manner in which a resin component formed by polymerization of a furan derivative in the solution or an attached furan derivative is contained in a wood material. It should be noted that, hereinafter, the "furan derivative resin solution" is also referred to as a "solution" for explanation. In addition, in the present disclosure, "attachment of a furan derivative to a wood material" refers to the furan derivative being bound to the outside (or surface) of a wood material or the inside of a wood material, or partially penetrating into a wood material.

[0033] The "normal temperature" in the present disclosure refers to the temperature in an environment where a person skilled in the art does not artificially change the temperature by heating, cooling, etc. (eg, ambient temperature), and typically refers to a temperature of 15 to 35°C, such as 20 to 30°C or 23 to 27°C.

[0034] In addition, "heating" in the present disclosure refers to a method of artificially raising the temperature to appropriately promote the polymerization of the furan derivative, and for example, refers to heating the wood material or its surrounding environment in a method of achieving a temperature condition of 40°C to 180°C, 60°C to 160°C, 70°C to 120°C, or 80°C to 100°C, or a temperature condition of 70°C to 160°C or 80°C to 150°C. It should be noted that the "temperature" in the present disclosure refers to the temperature of such a wood material or its surrounding environment, but for simplicity or convenience, it can also be regarded as the set temperature of the device used in the production (for example, the temperature set in the heating and warming means of the chamber).

[0035] It should be noted that in the present disclosure, the time of being placed at such a temperature can last for 2 to 240 hours, for example, 4 to 168 hours, 10 to 96 hours, 10 to 80 hours, or 10 to 48 hours. In a preferred embodiment, by carrying out the reaction at this temperature, the polymerization of the furan derivatives that have penetrated into the wood material and / or the adhesion to the wood material are more favorably promoted, and the wood material wetted by the furan derivative resinization solution is dried. In the production method of the present invention, after the furan derivatives are penetrated into the wood material, they can be quickly heated from room temperature. In addition, in another preferred embodiment, the wood material penetrated with the furan derivatives is placed at room temperature without heating, and the polymerization of the furan derivatives that have penetrated into the wood material and / or the adhesion to the wood material are promoted, and the wood material wetted by the furan derivative resinization solution is dried.

[0036] The "agent that promotes the polymerization of furan derivatives and / or the adhesion to wood materials" in the present disclosure can act in a manner that promotes the polymerization of furan derivatives and / or the adhesion to wood materials, for example, when the wood materials are resinified (for example, by placing the above-mentioned infiltration-treated wood materials at a temperature of 5°C or higher). For example, the "agent that promotes the polymerization of 5-HMF or its derivatives and / or the adhesion to wood materials" in the present disclosure is an agent that acts in a manner that promotes the polymerization of 5-HMF or its derivatives and / or the adhesion to wood materials, for example, when the wood materials are resinified (for example, by placing the above-mentioned infiltration-treated wood materials at a temperature of 5°C or higher). The "agent that promotes the polymerization of 5-HMF or its derivatives and / or the adhesion to wood materials" does not promote polymerization in the state of a solution monomer, but can serve as an agent that promotes the polymerization of 5-HMF or its derivatives and / or the adhesion to wood materials when it penetrates into the wood materials.

[0037] In addition, the "agent that promotes the polymerization of furan derivatives and / or the adhesion to wood materials" in the present disclosure may act in a manner that promotes the polymerization of furan derivatives and / or the adhesion to wood materials, for example, when the wood materials are resinified at room temperature without heating (for example, by leaving the above-mentioned infiltration-treated wood materials at room temperature). For example, the "agent that promotes the polymerization of 5-HMF or its derivatives" in the present disclosure may be an agent that acts in a manner that promotes the polymerization of 5-HMF or its derivatives and / or the adhesion to wood materials, for example, when the wood materials are resinified at room temperature without heating (for example, by leaving the above-mentioned infiltration-treated wood materials at room temperature). In the following description of the present invention, the "agent that promotes the polymerization of furan derivatives and / or the adhesion to wood materials" and the "agent that promotes the polymerization of 5-HMF and / or its derivatives and / or the adhesion to wood materials" are sometimes simply referred to as "promoters" for explanation.

[0038] The "wood material" in the present disclosure typically refers to so-called wood. The "wood material" can be, for example, a wood raw material for use in a wood product. That is, the wood material used in the manufacturing method of the present invention can be wood that has been temporarily processed or lumbered from a log to have a certain prescribed shape.

[0039] The furan derivative used in the production method of the present invention is not particularly limited, and may be, for example, a substance in which a hydrocarbon group (e.g., a hydrocarbon group having 1 to 40, 1 to 30, 1 to 20, 1 to 10, 1 to 8, 1 to 6, 1 to 4, 1 to 3, or 1 to 2 carbon atoms) is directly bonded to the furan skeleton, that is, a derivative substituted with such a hydrocarbon group. For example, as a furan derivative, there can be mentioned furan substituted with at least one functional group selected from alkyl, formyl, hydroxyl, and hydroxyalkyl. The number of carbon atoms of each functional group of the alkyl, formyl, hydroxyl, and hydroxyalkyl group may be 1 to 20, for example, 1 to 10, 1 to 8, 1 to 6, 1 to 4, 1 to 3, 1 to 2, or 1. In addition, the number of functional groups to be substituted may be 1 to 4, for example, 1 to 3, 1 to 2, or 1, per molecule of the furan derivative.

[0040] The furan derivative resin solution used in the production method of the present invention contains a “furan derivative.” For example, the furan derivative may be at least one polymerizable monomer selected from 5-hydroxymethylfurfural (5-HMF) and its derivatives.

[0041] For example, 5-HMF may be commercially available. Although this is just one example, commercially available products of Combi-Blocks, Tokyo Chemical Industry, Fujifilm Wako Pure Chemical Industries, Ltd., Kanto Chemical Co., Ltd., etc. may be used as 5-HMF.

[0042] Furan derivatives, such as 5-HMF and / or its derivatives, can stably exist in a solution using an aqueous solvent (particularly a solvent in which water is 100% by weight as the solvent in the solution). After penetrating into the wood material, the condensation polymerization and / or adhesion to the wood material are further promoted by the action of an accelerator at a temperature of 5° C. or higher, which is more preferable for resinification of the wood material.

[0043] Among furan derivatives, for example, when 5-HMF is used, the anti-swelling ability (ASE) of the modified wood tends to be higher. In a preferred embodiment, the ASE may be 50% or more, for example, 50-99%, 50-95%, or 50-90%.

[0044] Among furan derivatives, for example, when 5-HMF is used, the bending strength, compressive strength and / or hardness of the modified wood tend to become higher. In a preferred embodiment, the bending strength can be increased by 5% or more, for example, by 7% or more, or by 10% or more, or by 5-70%, 5-60%, 5-50%, 5-40%, 5-30%, 5-20%, 5-15%, 7-70%, 7-60%, 7-50%, 7-40%, 7-30%, 7-20% or 7-15%, etc.

[0045] The furan derivative resin solution used in the present invention may be an aqueous system. That is, the furan derivative resin solution used in the production method of the present invention may be a solution containing the above-mentioned furan derivative, an inorganic salt and / or its hydrate or anhydride that promotes the polymerization and / or adhesion of the furan derivative to the wood material, and / or an organic acid and / or its hydrate, anhydride and / or salt that can be formed, and water as a solvent. In particular, the solvent in the furan derivative resin solution may be an aqueous medium. This means that the solvent contained in the solution is substantially composed of 90% by weight or more, 93% by weight or more, 95% by weight or more, or 97% by weight or more of water or only water (100% by weight of water). In the present invention, "the solvent in the furan derivative resin solution is an aqueous medium" means that the solvent contained in the above-mentioned solution is a solvent composed of at least 90% by weight of water. Preferably, the furan derivative resin solution may contain only water as a solvent, and may not contain an organic solvent or organic solvent such as acetone. In a more direct preferred embodiment, the furan derivative resin solution used in the present invention may not contain acetone or the like.

[0046] More specifically, the solvent in the furan derivative resin solution may be a monomer solvent consisting of water alone, rather than a solvent consisting of a mixture. It should be noted that the solvent of the furan derivative resin solution used in the present invention in this example does not contain an organic solvent, and therefore may also be referred to as a non-organic solvent-based solvent (particularly, an aqueous medium containing 100% by weight or 100% by volume of water as a non-organic solvent-based solvent).

[0047] When the solvent of the furan derivative resin solution is an aqueous solvent consisting only of water, the effect of the present invention can be made more significant by performing a better modification of the wood material. Without being bound by a specific theory, it is believed that this is related to the fact that the furan derivative in the furan derivative resin solution is easier to reach the inner part of the wood material than when acetone or the like is contained as a solvent. Similarly, without being bound by a specific theory, it is believed that one of the main reasons is that the water used as the aqueous solvent has a higher polarity and / or a smaller molecular weight than acetone or the like, and therefore, a 100% aqueous solvent is easier to penetrate into the cell wall of the wood than when acetone or the like is contained in the solvent. It should be noted that the aqueous solvent can suppress the cost at a lower level when implementing the production method of the present invention, and is also relatively easier to be advantageous from the perspectives of safety and environmental protection compared to the case of using an organic solvent.

[0048] In the present invention, the type of water used as the aqueous solvent (i.e., an aqueous solvent consisting only of water as a solvent) is not particularly limited, and any water generally known can be used. Although it is only illustrative, the water used as the aqueous solvent can be at least one selected from tap water, purified water, groundwater, river water, rainwater, deionized water, and distilled water.

[0049] In certain embodiments, the furan derivative resin solution used in the present invention may contain a small amount of an organic solvent such as a monohydric alcohol to improve the solubility of the furan derivative, as required.

[0050] The concentration of the furan derivative in the furan derivative resin solution used in the production method of the present invention may be generally 5 to 50% by weight (excluding 50% by weight), for example, 5 to 45% by weight, 10 to 45% by weight, 20 to 45% by weight, 20 to 40% by weight, or 25 to 35% by weight, based on the entirety of the furan derivative resin solution. For example, the concentration of 5-HMF and / or its derivative in the 5-HMF resin solution used in the production method of the present invention may be generally 5 to 50% by weight (excluding 50% by weight), for example, 5 to 45% by weight, 10 to 45% by weight, 20 to 45% by weight, 20 to 40% by weight, or 25 to 35% by weight, based on the entirety of the 5-HMF and / or its derivative resin solution.

[0051] Such a concentration of furan derivatives, such as 5-HMF and / or its derivatives, can contribute to better modification of wood materials. For example, by using the solution to modify wood materials, it is easy to give the wood materials better anti-swelling ability (ASE) and at least one good property selected from bending strength, compressive strength and hardness.

[0052] The furan derivative resin solution used in the production method of the present invention contains "agents that promote polymerization of furan derivatives and / or adhesion to wood materials". For example, the 5-HMF and / or its derivative resin solution contains "agents that promote polymerization of 5-HMF and / or its derivatives and / or adhesion to wood materials". By adding the agent to the furan derivative resin solution, such as the 5-HMF and / or its derivative resin solution, when the furan derivatives in the solution penetrate into the wood material at 5°C or above for modification treatment, the polymerization of furan derivatives in the solution, such as the polymerization of 5-HMF and / or its derivatives and / or adhesion to wood materials can be more effectively promoted.

[0053] The "agent that promotes the polymerization of furan derivatives and / or the adhesion to wood materials" may be an agent that promotes the polymerization of furan derivatives and / or the adhesion to wood materials by drying at 5°C or above or by heating. For example, the "agent that promotes the polymerization of 5-HMF and / or its derivatives and / or the adhesion to wood materials" may be an agent that promotes the polymerization of furan derivatives and / or the adhesion to wood materials by drying at 5°C or above or by heating. The "promotion of polymerization" mentioned here means that the presence of such an agent increases the rate of polymerization reaction of furan derivatives, such as 5-HMF and / or its derivatives, compared with the case where the agent is not present (for example, the case where a polymerizable monomer is present alone). In addition, "promotion of adhesion to wood materials" means that the presence of such an agent increases the rate and amount of furan derivatives, such as 5-HMF and / or its derivatives adhering to wood materials when they penetrate into wood materials, compared with the case where the agent is not present (for example, the case where a polymerizable monomer is present alone). Such a reagent may be an acidic, for example, weakly acidic reagent in an aqueous solution (for example, an aqueous solution at room temperature), and may be a reagent that changes the pH of a furan derivative resin solution, for example, a 5-HMF and / or its derivative resin solution, to the acidic side (i.e., further lowers the pH). For example, the reagent may be neutral to weakly acidic as an aqueous solution at room temperature, typically at pH 3 to 7 (excluding "7"), for example, at pH 4 to 6.5 or pH 5 to 6, etc.

[0054] In addition, in this disclosure, "pH" means a hydrogen ion index, and may be, for example, a pH value measured according to "JIS Z 8802 pH measurement method".

[0055] In the production method of the present invention, the "agent that promotes the polymerization of furan derivatives and / or the adhesion to wood materials", for example, the "agent that promotes the polymerization of 5-HMF and / or its derivatives and / or the adhesion to wood materials" is an inorganic salt and / or its hydrate or anhydride, and / or an organic acid and / or its hydrate, anhydride and / or salt that can be formed. In the production method of the present invention, the inorganic salt used as the "agent that promotes the polymerization of furan derivatives and / or the adhesion to wood materials", for example, the "agent that promotes the polymerization of 5-HMF and / or its derivatives and / or the adhesion to wood materials" can be an inorganic salt composed of anions of chloride ions and / or sulfate ions, and cations of ammonium ions and / or magnesium ions and / or hydrogen ions. If it is such an inorganic salt, it can contribute to better modification of wood materials.

[0056] In the production method of the present invention, the "reagent for promoting polymerization of furan derivatives and / or adhesion to wood materials" is not particularly limited as long as it promotes polymerization of at least a portion of a furan derivative resin solution such as a 5-HMF resin solution (preferably a 5-HMF or other furan derivative resin solution such as a 5-HMF resin solution that permeates into a wood material) or adhesion to a wood material by leaving it at room temperature or heating it from room temperature. For example, the "reagent for promoting polymerization of 5-HMF and / or its derivatives and / or adhesion to a wood material" may be a reagent selected from ammonium chloride, magnesium chloride hexahydrate, maleic acid, citric acid, ammonium sulfate, ammonium hydrogen sulfate, and the like.

[0057] For example, by modifying a wood material using the solution, it is easy to impart to the wood material better anti-swelling ability (ASE) and / or at least one good property selected from flexural strength, compressive strength or hardness, particularly anti-swelling ability (ASE).

[0058] In a preferred embodiment, the "agent for promoting polymerization of furan derivatives and / or adhesion to wood materials", for example, the "agent for promoting polymerization of 5-HMF and / or its derivatives and / or adhesion to wood materials" may be an inorganic salt. For example, such an inorganic salt may be an inorganic salt having a combination of any one of chloride ions and sulfate ions and one or two selected from ammonium ions, magnesium ions and hydrogen ions as constituent elements.

[0059] For example, "an inorganic salt that promotes the polymerization of furan derivatives and / or their adhesion to wood materials", for example, "an inorganic salt that promotes the polymerization of 5-HMF and / or its derivatives and / or their adhesion to wood materials" can be at least one inorganic salt selected from magnesium chloride, ammonium chloride, ammonium sulfate, ammonium hydrogen sulfate, magnesium sulfate and magnesium hydrogen sulfate.

[0060] In addition, in the production method of the present invention, the organic acid used as the "agent for promoting the polymerization of furan derivatives and / or the adhesion to wood materials", for example, the "agent for promoting the polymerization of 5-HMF and / or its derivatives and / or the adhesion to wood materials", or the hydrate, anhydride or salt thereof that can be formed can be one or more organic acids selected from saturated or unsaturated aliphatic hydrocarbons having 1 to 20, 1 to 6 or 1 to 4 carbon atoms, which may have halogen, amino and / or hydroxyl groups, and one or more carboxyl groups and / or sulfonic groups, and 3 to 20, 3 to 18 or 6 to 12 carbon atoms, which may have halogen, amino and / or hydroxyl groups, and one or more carboxyl groups and / or sulfonic groups. In addition, the organic acid used as the "agent for promoting the polymerization of furan derivatives and / or the adhesion to wood materials", for example, the "agent for promoting the polymerization of 5-HMF and / or its derivatives and / or the adhesion to wood materials", may be a hydrate, anhydride or salt that can be formed by the above-mentioned organic acid, or one or more of them may be used in combination.

[0061] For example, "an organic acid or its hydrate, anhydride or salt that promotes the polymerization of furan derivatives and / or the adhesion to wood materials", for example, "an organic acid or its salt that promotes the polymerization of 5-HMF and / or its derivatives and / or the adhesion to wood materials" can be at least one organic acid selected from formic acid, acetic acid, oxalic acid, maleic acid, citric acid, glucuronic acid, methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, camphorsulfonic acid, fluorosulfonic acid and taurine, or a hydrate, anhydride or salt that can be formed by them.

[0062] In the furan derivative resin solution, for example, the 5-HMF and / or its derivative resin solution, the concentration or amount of the "agent for promoting polymerization of the furan derivative and / or adhesion to the wood material", for example, the "agent for promoting polymerization of 5-HMF and / or its derivative and / or adhesion to the wood material", can be 0.1 mol or less, 0.09 mol or less, 0.08 mol or less, 0.07 mol or less, 0.06 mol or less, 0.05 mol or less, 0.04 mol or less, 0.03 mol or less, 0.02 mol or less, etc., relative to 1 mol of the furan derivative, for example, 5-HMF and / or its derivative in the solution. The lower limit value in this case can be a value greater than 0 mol. For example, when the upper limit is 0.1 mol, the concentration or amount of the "agent for promoting polymerization of furan derivatives and / or adhesion to wood materials", for example, the "agent for promoting polymerization of 5-HMF and / or adhesion to wood materials" contained in the furan derivative resinization solution, for example, the 5-HMF and / or derivative resinization solution, relative to 1 mol of the furan derivative, for example, 5-HMF and / or its derivatives, can be 0.001 to 0.1 mol, 0.002 to 0.1 mol, 0.003 to 0.1 mol, 0.004 to 0.1 mol, 0.005 to 0.1 mol, 0.006 to 0.1 mol, 0.007 to 0.09 mol, 0.008 to 0.08 mol, 0.009 to 0.07 mol, etc. If the "agent for promoting polymerization of furan derivatives and / or adhesion to wood materials", for example, "agent for promoting polymerization of 5-HMF and / or its derivatives and / or adhesion to wood materials", is in such a concentration or amount, it can contribute to better modification of wood materials. For example, by modifying wood materials using the solution, it is easy to impart better anti-swelling ability (ASE) and / or at least one good property selected from bending strength, compressive strength or hardness to the wood materials.

[0063] The wood material to be the object of the manufacturing method of the present invention is not particularly limited, and any wood material equivalent to so-called wood can be used. For example, as the wood material to be the object of the manufacturing method of the present invention, at least one Japanese coniferous tree selected from Cryptomeria japonica, Chamaecyparis obtusifolia, pine, Japanese larch, Japanese fish-scale pine, Abies kaempferi, Japanese hemlock and Japanese fir can be cited. In addition, as the wood material, at least one non-Japanese coniferous tree selected from American southern yellow pine, New Zealand radiata pine, European red pine, Cunninghamia lanceolata and Douglas fir can also be cited. Furthermore, in addition to solid wood materials from fast-growing soft broad-leaved trees such as poplar and / or neem, wood materials that have been processed to a certain extent, such as integrated timber, plywood, veneer, plastic plywood and / or fiberboard, as well as the laminated boards (rough sawn boards), veneers, wood chips, wood powder and / or wood fibers (pulp) that constitute them, can also be used. Furthermore, non-wood-based wood cellulose materials such as bamboo can be used.

[0064] The wood material modified by the manufacturing method of the present invention can be used for various indoor and / or outdoor products. For example, the wood material modified by the manufacturing method of the present invention can be used for furniture, wooden floors, wooden decks, exterior walls, blinds, truck bodies, musical instruments, interior materials, residential exterior building materials, etc.

[0065] In a preferred embodiment, the wood material is a coniferous material. In this case, the effect of the present invention can be made more significant. Originally, these wood materials have limited uses due to their low dimensional stability and / or bending strength, compression strength or hardness, but such properties can be improved by the manufacturing method of the present invention and can be applied to a wider range of uses. The coniferous material can be, for example, cedar and / or cypress. Cedar and / or cypress can be equivalent to Japanese coniferous material, which is appropriately conducive to the development of new uses and added value of Japanese coniferous trees.

[0066] Although it is just an example, the moisture content of the modified wood material (i.e., the wood material before modification or non-modified) can be adjusted to be less than 30 weight %, for example, less than 25 weight %, less than 20 weight % or less than 15 weight %, etc. (the lower limit in this case can be a value greater than 0 weight %) based on the total weight of the wood material.

[0067] As described above, the furan derivative resin solution used in the production method of the present invention, such as 5-HMF and / or its derivative resin solution, preferably contains a promoter as a solute component other than the furan derivative, such as 5-HMF and / or its derivative. That is, it contains "agents that promote polymerization of furan derivatives and / or adhesion to wood materials". In particular, the furan derivative resin solution used in the production method of the present invention, such as 5-HMF and / or its derivative resin solution, is a solution containing inorganic salts, organic salts and / or oxidative polymerization agents that can act as "promoters". Such a solution can contribute to better modification of wood materials. For example, by using the modification treatment of wood materials using the solution, it is easy to give the wood materials better anti-swelling ability (ASE) and at least one property selected from bending strength, compressive strength and hardness.

[0068] Preferably, such an accelerator (agent that promotes polymerization of furan derivatives and / or adhesion to wood materials at a temperature of 5°C or higher), such as an inorganic salt, forms a solution together with a furan derivative, such as 5-HMF and / or its derivatives, and a solvent (containing water alone or a mixed solvent containing water and alcohols, such as ethanol as a solvent). In particular, a furan derivative resin solution, such as 5-HMF and / or its derivative resin solution, containing an accelerator and a monomer solvent consisting of only water alone or a mixed solvent consisting of water and alcohols, as described above, can make the effect of the modification treatment of wood materials more significant.

[0069] In the production method of the present invention, as step 1), a treatment is performed to make a furan derivative resin solution, such as 5-HMF and / or its derivative resin solution, penetrate into a wood material. As long as the penetration is conducive, the means is not particularly limited. For example, a chamber that can be loaded with a wood material and a furan derivative resin solution, such as 5-HMF and / or its derivative resin solution can be used. It should be noted that in step 1), a method of immersing a wood material in a furan derivative resin solution, such as 5-HMF and / or its derivative resin solution, and / or spraying or applying a furan derivative resin solution, such as 5-HMF and / or its derivative resin solution to a wood material, and / or a method of impregnating a wood material with a furan derivative resin solution, such as 5-HMF and / or its derivative resin solution under reduced pressure and / or pressurized conditions can be used.

[0070] When the shape and size of wood materials such as veneers, wood chips, wood powder and / or wood fibers (pulp) are thin or small wood materials, the desired penetration can be easily achieved by treatments such as impregnation, coating, spraying, etc. On the other hand, when wood materials such as solid wood materials and laminated boards have a cross-sectional size of a certain degree or more, if an impregnation treatment under a reduced pressure and / or pressurized environment is adopted, that is, the so-called reduced pressure / pressurized impregnation method, the desired penetration can be easily achieved.

[0071] In other words, step 1) can be carried out under a reduced pressure less than atmospheric pressure. Such reduced pressure conditions may also depend on the shape and / or size of the wood material to be modified, for example, it may be a reduced pressure condition of less than atmospheric pressure to 10 hPa in a temperature range below room temperature. Under this reduced pressure condition, it can be more preferably helpful for the solution to penetrate into the wood material. For example, by using the modification treatment of the wood material with the solution, it is easy to give the wood material a better anti-swelling ability (ASE) and at least one good property selected from bending strength, compressive strength and hardness. The reduced pressure conditions of step 1) (for example, the pressure in the chamber) may be, for example, reduced pressure conditions such as 700-10 hPa, 500-10 hPa, 100-10 hPa, 75-10 hPa, 50-10 hPa, 40-10 hPa, or 40-20 hPa. The time for applying the furan derivative resin solution, such as 5-HMF and / or its derivative resin solution, to the wood material under reduced pressure is typically 5 minutes to 16 hours, such as 30 minutes to 16 hours, 1 hour to 16 hours, 1 hour to 8 hours, 1 hour to 4 hours, or 1 hour to 3 hours.

[0072] In the manufacturing method of the present invention, atmospheric pressure conditions or pressurized conditions can be appropriately used. For example, a pressurized treatment can also be performed after the above-mentioned reduced pressure treatment. In such a treatment, atmospheric pressure or an atmospheric pressure higher than it can be used. For example, a pressure condition of 0.1 to 3 MPa or 0.3 to 2 MPa (for example, the pressure in the chamber) can be used. The time for which the wood material is subjected to such pressure and pressurized conditions can typically be 15 minutes to 72 hours, for example, 30 minutes to 36 hours, or 1 hour to 12 hours.

[0073] In the production method of the present invention, as step 2), at least a portion of the furan derivative, such as 5-HMF and / or its derivatives, which has penetrated into the wood material is polymerized in the wood material and / or attached to the wood material at a temperature of 5° C. or higher. By placing at room temperature or heating, polymerization of the furan derivative, such as 5-HMF and / or its derivatives in the resinized solution of the furan derivative in the wood material and / or adhesion to the wood material are promoted, and modification of the wood material can be performed due to the modification of the resin component and / or the wood material produced thereby.

[0074] When artificially heating in step 2), there is no particular limitation on the means as long as the temperature of the wood material infiltrated with the solution can be raised. For example, heating can be performed by raising the temperature of the chamber in which the wood material is placed (for example, the temperature of the atmosphere in the chamber).

[0075] Such heating may be performed at room temperature to 180°C. That is, step 2) of the production method of the present invention may be performed under temperature conditions of room temperature to 180°C. Alternatively, the heating in step 2) may be performed under temperature conditions of 40 to 180°C, 40 to 170°C, 40 to 160°C, 60 to 180°C, 60 to 170°C, 60 to 160°C, 80 to 180°C, 80 to 150°C, 80 to 140°C, 80 to 120°C. In addition, the heating in step 2) may be performed at 90 to 140°C, 100 to 140°C, 110 to 140°C, 120 to 140°C, etc. Under such heating conditions, it is possible to contribute to better modification of the wood material. For example, by using the modification treatment of the wood material using the solution, it is easy to impart better anti-swelling ability (ASE) and at least one property selected from bending strength, compressive strength and hardness to the wood material. Furthermore, the heating temperature in step 2) (eg, the temperature in the chamber) may be 40 to 250°C, 60 to 125°C, 60 to 120°C, or 60 to 100°C.

[0076] The time for the wood material to be treated at room temperature or during the heat treatment in step 2) can typically be 2 to 240 hours, for example, 4 to 168 hours, 4 to 96 hours, 10 to 96 hours, 10 to 80 hours or 10 to 48 hours, or can be 4 to 48 hours, 4 to 30 hours or 10 to 30 hours, further, can be 4 to 24 hours, 4 to 10 hours or 4 to 8 hours, etc.

[0077] The heating in step 2) can be performed in an air atmosphere. However, the heating is not limited thereto, and when heating at a relatively high temperature (for example, heating exceeding 100° C.), the heating can be performed in an inert gas atmosphere such as steam and / or nitrogen.

[0078] During the heating in step 2), the wood material infiltrated with the solution may be dried. For example, by heating in step 2), the furan derivative of the infiltrated furan derivative resinizing solution, for example, 5-HMF and / or its derivative resinizing solution, may be polymerized in the wood material, and the wood material may be dried. In other words, for example, in a chamber in which the wood material infiltrated with the furan derivative resinizing solution, for example, 5-HMF and / or its derivative resinizing solution, is added, a heating treatment is performed at a temperature condition of 60 to 160° C. (for example, a process temperature condition of 80 to 160° C., 80 to 150° C., 90 to 150° C., 90 to 120° C., 90 to 110° C., or 100 to 150° C., 110 to 140° C., or 120 to 140° C.) for 2 to 240 hours or 2 to 260 hours (for example, 3 to 192 hours, 3 to 192 hours). ~168 hours, 4~168 hours, 4~96 hours, 10~96 hours, 10~80 hours or 10~48 hours, or 4~48 hours, 4~30 hours or 10~30 hours, or 4~24 hours, 4~10 hours or 4~8 hours, etc.), thereby, the furan derivatives such as 5-HMF and / or its derivatives that penetrate into the wood material can be polymerized and / or attached to the wood material, and the wood material (wood material wetted by the penetration of the solution) can be dried in parallel or thereafter.

[0079] Furan derivatives, such as 5-HMF and / or its derivatives, have high stability, so the furan derivative resin solution, such as 5-HMF and / or its derivative resin solution, used in the production method of the present invention may not contain a stabilizer that inhibits unintended polymerization of furan derivatives, such as 5-HMF and / or its derivatives in an aqueous medium (for example, unintended polymerization that can be seen as turbidity, insolubility and / or separation in the solution). That is, although it is conceivable to use such a stabilizer to produce a modified wood material, in the case of a furan derivative resin solution such as a 5-HMF resin solution, the modified wood material may be produced without using the stabilizer (in other words, in one embodiment, the furan derivative resin solution of the present invention does not contain "a component that inhibits polymerization of furan derivatives at room temperature (for example, an inorganic substance containing an inorganic salt that inhibits polymerization of furan derivatives at room temperature)").

[0080] Alternatively, if desired, in order to further stabilize the furan derivatives, such as 5-HMF and / or its derivatives, in the aqueous solvent during long-term storage at room temperature or storage under a high temperature environment exceeding room temperature, "an inorganic substance containing an inorganic salt that inhibits the polymerization of the furan derivative at room temperature" may be contained in the furan derivative resinification solution. For example, "an inorganic substance containing an inorganic salt that inhibits the polymerization of 5-HMF and / or its derivatives at room temperature" may be contained in the 5-HMF and / or its derivative resinification solution. "An inorganic substance containing an inorganic salt that inhibits the polymerization of the furan derivative at room temperature", such as "an inorganic substance containing an inorganic salt that inhibits the polymerization of 5-HMF and / or its derivatives at room temperature", may be, for example, ammonia, an inorganic carbonate, etc. In addition to or instead of this, "an inorganic substance containing an inorganic salt that inhibits the polymerization of the furan derivative at room temperature", such as "an inorganic substance containing an inorganic salt that inhibits the polymerization of 5-HMF and / or its derivatives at room temperature", may be in the form of ammonia or an ammonium salt.

[0081] In some embodiments, "an inorganic substance containing an inorganic salt that inhibits the polymerization of furan derivatives at room temperature", for example, "an inorganic substance containing an inorganic salt that inhibits the polymerization of 5-HMF and / or its derivatives at room temperature" may be at least one inorganic salt selected from ammonia, ammonium carbonate, and ammonium bicarbonate. Specifically, "an inorganic substance containing an inorganic salt that inhibits the polymerization of furan derivatives at room temperature", for example, "an inorganic substance containing an inorganic salt that inhibits the polymerization of 5-HMF and / or its derivatives at room temperature" may be, for example, ammonia, ammonium carbonate, ammonium bicarbonate, or a combination of two or three selected from ammonia, ammonium carbonate, and ammonium bicarbonate. This is because an inorganic substance containing an inorganic salt that inhibits the unintended polymerization of furan derivatives in the solution at room temperature, for example, 5-HMF and / or its derivatives at room temperature, can be formed, and the quality stability of the solution before infiltration into the wood material can be better maintained, and in addition, the polymerization of furan derivatives, for example, 5-HMF and / or its derivatives, is not hindered during heating after infiltration. The term “inhibiting polymerization” as used herein means that the presence of an inorganic substance including such an inorganic salt reduces or stops the polymerization reaction rate of a furan derivative, such as 5-HMF and / or its derivatives, compared to the absence of the inorganic substance (such as the presence of a polymerizable monomer alone).

[0082] “An inorganic substance containing an inorganic salt that inhibits the polymerization of furan derivatives at room temperature”, for example, “an inorganic substance containing an inorganic salt that inhibits the polymerization of 5-HMF and / or its derivatives at room temperature” may be an inorganic substance containing an inorganic salt that is alkaline in an aqueous solution (for example, an aqueous solution at room temperature), for example, it may be an inorganic substance containing an inorganic salt that is alkaline in a furan derivative resinification solution, for example, a 5-HMF and / or its derivative resinification solution, making the solution alkaline or changing the pH to a more alkaline side (i.e., further increasing the pH). Incidentally, even if a salt such as sodium hydroxide and / or potassium hydroxide is added to a furan derivative resin solution containing a furan derivative such as 5-HMF and / or its derivatives, an inorganic salt that is neutral to weakly acidic at room temperature and promotes polymerization of the furan derivative, and water, and the furan derivative resin aqueous solution such as 5-HMF and / or its derivative resin solution is kept alkaline, it is considered that the polymerization of the furan derivative such as 5-HMF and / or its derivatives can be inhibited to maintain the stability of the solution, but such a salt unexpectedly inhibits the polymerization of the furan derivative such as 5-HMF and / or its derivatives during the subsequent heating. That is, it inhibits the desired polymerization during the modification treatment of the wood material.

[0083] As for the inorganic substance which inhibits the polymerization of furan derivatives, such as 5-HMF and / or its derivatives at room temperature, but does not unexpectedly inhibit the polymerization of furan derivatives, such as 5-HMF and / or its derivatives after the resinified solution of furan derivatives, such as 5-HMF and / or its derivatives, is made to penetrate into the wood material, although there are some limitations, for example, inorganic substances which are decomposed and gasified by heating and removed to the outside of the reaction system can be used. As typical examples thereof, inorganic salts such as ammonium carbonate and / or ammonium bicarbonate, and inorganic substances such as ammonia can be cited.

[0084] From the above viewpoint, it can be said that the inorganic substance containing the above-mentioned inorganic salt in the furan derivative resin solution used in the production method of the present invention, for example, the 5-HMF and / or its derivative resin solution, is preferably an inorganic substance containing an inorganic salt that decomposes and vaporizes by heating. That is, the "inorganic substance containing an inorganic salt that inhibits polymerization of the furan derivative at room temperature" contained in the furan derivative resin solution, for example, the 5-HMF and / or its derivative resin solution, may be an inorganic substance containing an inorganic salt that decomposes by heating (more specifically, decomposes and vaporizes by heating) after the furan derivative resin solution, for example, the 5-HMF and / or its derivative resin solution, is infiltrated into the wood material. From the same viewpoint, as the inorganic substance containing the inorganic salt in the furan derivative resin solution used in the production method of the present invention, for example, the 5-HMF and / or its derivative resin solution, it is preferred to exclude sodium hydroxide and potassium hydroxide. In other words, the "inorganic substance containing an inorganic salt that inhibits polymerization of the furan derivative at room temperature" contained in the furan derivative resinification solution, for example, 5-HMF and / or its derivative resinification solution, is preferably an inorganic substance containing an inorganic salt other than sodium hydroxide and potassium hydroxide.

[0085] The content of these inorganic salts can be appropriately adjusted. By adjusting the content, it is easy to control the degree of polymerization and / or adhesion of the furan derivative, such as 5-HMF and / or its derivatives to the wood material at a temperature of 5°C or above after the furan derivative resin solution, such as 5-HMF and / or its derivatives resin solution, is infiltrated into the wood material, and it is easy to control the location of the wood material cell where the furan resin, such as 5-HMF and / or its derivatives resin, is generated. For example, if the content of "inorganic matter containing inorganic salts that inhibit the polymerization of furan derivatives at room temperature", such as "inorganic matter containing inorganic salts that inhibit the polymerization of 5-HMF and / or its derivatives at room temperature" in the solution is further increased, it is easy to control the polymerization degree of the furan derivative, such as 5-HMF and / or its derivatives, to be low, and the low molecular weight furan derivative resin is easy to be generated in the cell wall. On the other hand, for example, if the content of "inorganic matter including inorganic salts that inhibit the polymerization of furan derivatives at room temperature", for example, "inorganic matter including inorganic salts that inhibit the polymerization of 5-HMF and / or its derivatives at room temperature" is further reduced, it is easy to control the degree of polymerization of furan derivatives, such as 5-HMF and / or its derivatives, to be higher, and high-molecular-weight furan resins are easily generated and accumulated in the cell cavity.

[0086] It should be noted that, as described above, the inorganic substance containing these inorganic salts as stabilizers can stabilize the state of the furan derivative resin solution, such as 5-HMF and / or its derivative resin solution, before penetrating into the wood by inhibiting the polymerization of furan derivatives, such as 5-HMF and / or its derivatives at room temperature, so that the modification treatment using it can help improve the characteristics of the modified wood material. In addition, it is also possible to further reduce the unevenness of the finished state of the modified wood material, and it is also easy to achieve uniformity of the quality of the final product using the modified wood material. In the present disclosure, "an inorganic substance containing an inorganic salt that inhibits the polymerization of furan derivatives at room temperature" or "an inorganic substance containing an inorganic salt that inhibits the polymerization of 5-HMF and / or its derivatives at room temperature" is sometimes referred to as a stabilizer.

[0087] In the present invention, in order to easily impart desired properties to the wood material, polymerization in a solution can be appropriately considered. Although this is only an exemplary embodiment, for example, in the initial polymerization of the furan derivative, the molecular weight and reactivity of the polymer (resin) generated are controlled, and the polymerization of the furan derivative in the solution resinification solution is suppressed, and at the same time, after the furan derivative is infiltrated into the wood material, it is possible to promote the polymerization reaction in the wood material well.

[0088] In the furan derivative resinizing solution, the concentration of the "inorganic substance including an inorganic salt that inhibits the polymerization of the furan derivative at room temperature" may be 0.01 mol or less, 0.005 mol or less, 0.004 mol or less, 0.003 mol or less, 0.002 mol or less, or 0.001 mol or less (the lower limit in this case may be a value greater than 0 mol) relative to 1 mol of the furan derivative in the solution. For example, in the furan derivative resinizing solution, the concentration or amount of the "inorganic substance including an inorganic salt that inhibits the polymerization of the furan derivative at room temperature" may be 0.0001 to 0.004 mol, for example, 0.0003 to 0.003 mol, 0.0005 to 0.001 mol, 0.0006 to 0.001 mol, or 0.0007 to 0.0009 mol, etc. relative to 1 mol of the furan derivative in the solution. If the "inorganic substance containing an inorganic salt that inhibits the polymerization of furan derivatives at room temperature" is in such a concentration or amount, it can contribute to better modification of wooden materials. For example, by modifying wooden materials using the solution, it is easy to impart to wooden materials better dimensional stability and at least one good property selected from bending strength, compressive strength and hardness.

[0089] By adding the inorganic substance containing the inorganic salt to the furan derivative resin solution, the furan derivative becomes more stable, for example, in a room temperature solution. That is, even when the solution is stored for a long time (for example, when it is left at room temperature for a long time) or stored in an environment exceeding room temperature (for example, when it is exposed to a high temperature exceeding room temperature), it is easy to suppress the unexpected polymerization of the furan derivative (for example, unexpected polymerization that can be seen as turbidity, insolubility and / or separation phenomenon in the solution), and the furan derivative resin solution can be used in a better state during the modification treatment. It should be noted that such an "inorganic substance containing an inorganic salt that suppresses the polymerization of the furan derivative at room temperature" can achieve better quality stability of the solution before it penetrates into the wood material due to the suppression of the unexpected polymerization of the furan derivative, and can better suppress the unevenness of the characteristics imparted to the wood material by the treatment. For example, the unevenness of at least one characteristic selected from the group consisting of anti-swelling ability (ASE) and bending strength, compression strength and hardness can be better suppressed.

[0090] The "inorganic substance containing an inorganic salt that inhibits the polymerization of furan derivatives at room temperature" may be, for example, an inorganic carbonate. In addition or instead of this, the "inorganic substance containing an inorganic salt that inhibits the polymerization of furan derivatives at room temperature" may be in the form of an ammonium salt, for example. In addition, the "inorganic substance containing an inorganic salt that inhibits the polymerization of furan derivatives at room temperature" may be ammonia.

[0091] In a preferred embodiment, the "inorganic substance containing an inorganic salt that inhibits the polymerization of furan derivatives at room temperature" may be at least one inorganic salt selected from ammonium carbonate and ammonium bicarbonate. Specifically, the "inorganic substance containing an inorganic salt that inhibits the polymerization of furan derivatives at room temperature" may be, for example, ammonium carbonate, ammonium bicarbonate, or a combination of ammonium carbonate and ammonium bicarbonate. This is because the unexpected polymerization of furan derivatives in the solution can be inhibited at room temperature, and the quality stability of the solution before penetration into the wood material can be better maintained. In addition, during the heating after penetration, an inorganic salt that does not hinder the polymerization of furan derivatives can be formed. In addition, in a preferred embodiment, the "inorganic substance containing an inorganic salt that inhibits the polymerization of furan derivatives at room temperature" may be ammonia. Specifically, the "inorganic substance containing an inorganic salt that inhibits the polymerization of furan derivatives at room temperature" may be, for example, ammonia, ammonium carbonate, ammonium bicarbonate, or a combination of two or three selected from ammonia, ammonium carbonate and ammonium bicarbonate. This is because the unintended polymerization of the furan derivative in the solution can be suppressed at room temperature, and the quality stability of the solution before infiltration into the wood material can be better maintained. In addition, during the heating after infiltration, an inorganic substance containing an inorganic salt that does not inhibit the polymerization of the furan derivative can be formed. It should be noted that the "inhibition of polymerization" mentioned here means that the rate of the polymerization reaction is reduced or stopped by the presence of such an inorganic salt compared to the case where it does not exist (for example, the case where the polymerizable monomer exists alone).

[0092] The "inorganic salt that inhibits the polymerization of furan derivatives at room temperature" may be an inorganic salt that is alkaline in an aqueous solution (e.g., an aqueous solution at room temperature), and may be, for example, an inorganic salt that makes the solution alkaline or changes the pH to a more alkaline side (i.e., further increases the pH) in a furan derivative resinization solution. Incidentally, even if a salt such as sodium hydroxide and / or potassium hydroxide is added to a furan derivative resinization solution containing a furan derivative, an inorganic salt that promotes the polymerization of the furan derivative and is neutral to weakly acidic at room temperature, and water, and the furan derivative resin aqueous solution is kept alkaline, it is considered that the polymerization of the furan derivative can be inhibited to maintain the stability of the solution, but such a salt unexpectedly inhibits the polymerization of the furan derivative during the subsequent heating. That is, it inhibits the desired polymerization during the modification treatment of the wood material.

[0093] Although the salt inhibits the polymerization of the furan derivative at room temperature, on the other hand, does not unexpectedly inhibit the polymerization of the furan derivative after the furan derivative resin solution is infiltrated into the wood material, there are some limitations, and for example, salts that are decomposed and gasified by heating and removed to the outside of the reaction system can be used. Typical examples thereof include inorganic salts such as ammonium carbonate and / or ammonium bicarbonate.

[0094] From the above viewpoints, it can be said that the above-mentioned inorganic salt in the furan derivative resin solution used in the production method of the present invention is preferably an inorganic salt that decomposes and vaporizes by heating. That is, the "inorganic salt that inhibits the polymerization of the furan derivative at room temperature" contained in the furan derivative resin solution can be an inorganic salt that decomposes by heating (more specifically, decomposes and vaporizes by heating) after the furan derivative resin solution is infiltrated into the wood material. From the same viewpoint, as the inorganic salt in the furan derivative resin solution used in the production method of the present invention, sodium hydroxide and potassium hydroxide are preferably excluded. In other words, the "inorganic salt that inhibits the polymerization of the furan derivative at room temperature" contained in the furan derivative resin solution is preferably an inorganic salt other than sodium hydroxide and potassium hydroxide.

[0095] The content of these inorganic salts can be adjusted appropriately. By adjusting the content, it is easy to control the degree of polymerization of the furan derivatives by heating after the furan derivative resin solution is infiltrated into the wood material, and then it is easy to control the location of the wood material cells where the furan resin is generated. For example, if the content of "inorganic salts that inhibit the polymerization of furan derivatives at room temperature" in the solution is further increased, it is easy to control the polymerization degree of the furan derivatives to be lower, and low-molecular-weight furan derivative resins are easily generated in the cell wall. On the other hand, for example, if the content of "inorganic salts that inhibit the polymerization of furan derivatives at room temperature" is further reduced, it is easy to control the polymerization degree of the furan derivatives to be higher, and high-molecular-weight furan resins are easily generated and accumulated in the cell cavity.

[0096] As described above, inorganic salts as stabilizers can stabilize the state of the furan derivative resin solution before it penetrates into the wood by inhibiting the polymerization of the furan derivative at room temperature, so that the modification treatment using the inorganic salts can contribute to improving the properties of the modified wood material. In addition, the unevenness of the finished state of the modified wood material can be further reduced, and the quality of the final product using the modified wood material can be easily uniformed.

[0097] In the present invention, in order to easily impart desired properties to the wood material, polymerization in a solution can be appropriately considered. Although this is only an exemplary embodiment, for example, in the initial polymerization of the furan derivative, the molecular weight and reactivity of the polymer (resin) generated are controlled, and the polymerization of the furan derivative in the furan derivative resinification solution at room temperature is suppressed, and at the same time, after infiltration into the wood material, the polymerization reaction in the wood material can be well promoted by heating.

[0098] In the furan derivative resinizing solution, the concentration of the "inorganic salt that inhibits the polymerization of the furan derivative at room temperature" may be 0.01 mol or less, 0.005 mol or less, 0.004 mol or less, 0.003 mol or less, 0.002 mol or less, or 0.001 mol or less (the lower limit in this case may be a value greater than 0 mol) relative to 1 mol of the furan derivative in the solution. For example, in the furan derivative resinizing solution, the concentration or amount of the "inorganic salt that inhibits the polymerization of the furan derivative at room temperature" may be 0.0001 to 0.004 mol, for example, 0.0003 to 0.003 mol, 0.0005 to 0.001 mol, 0.0006 to 0.001 mol, or 0.0007 to 0.0009 mol, etc., relative to 1 mol of the furan derivative in the solution. If the "inorganic salt that inhibits the polymerization of the furan derivative at room temperature" is in such a concentration or amount, it can contribute to better modification of the wood material. For example, by modifying a wood material using the solution, it is easy to impart to the wood material better anti-swelling ability (ASE) and / or at least one good property selected from bending strength, compressive strength, or hardness.

[0099] If desired, in order to stabilize the furan derivative in the solvent during long-term storage at room temperature or storage under a harsh environment such as low temperature, when a stabilizer is included in the furan derivative resin solution, the wooden material may be subjected to a heating treatment at a heating temperature condition lower than the heating temperature before heating in one form of step 2). In other words, during the heating treatment, the "wooden material after solution infiltration" may be temporarily given a condition of "initial setting temperature". By giving such an "initial setting temperature" (i.e., heating treatment at the initial setting temperature), at least a part of the stabilizer of the furan derivative resin solution can be decomposed in the wooden material infiltrated with the solution. For example, by giving the "initial setting temperature", at least a part of the stabilizer in the furan derivative resin solution can be decomposed in a manner that the solution does not evaporate as much as possible for the wooden material after solution infiltration, which can contribute to better modification of the wooden material. That is, by using the modification treatment of the wooden material with the solution, it is easy to give the wooden material better anti-swelling ability (ASE) and at least one property selected from bending strength, compressive strength and hardness.

[0100] In the heating treatment performed at the "initial setting temperature", the wood material after the solution is infiltrated may be heated, for example, in a furan derivative resinizing solution, so that the impregnated solution is not evaporated as much as possible. For example, as the treatment at the initial setting temperature, instead of directly raising the temperature to the desired heating temperature of step 2), a treatment may be performed in which a temperature lower than the desired heating temperature (a temperature that can be touched later) is temporarily maintained for a certain period of time (it can also be said that the temperature changes with time in a step-like manner). Although it is only one example, in the heating treatment performed at the "initial setting temperature", the wood material after the solution is infiltrated may be heated, for example, in a furan derivative resinizing solution, so that the impregnated solution is not evaporated as much as possible, so that at least a part or all of the stabilizer (i.e., an inorganic salt that inhibits polymerization of the furan derivative at room temperature) in the furan derivative resinizing solution that may be contained as desired is decomposed.

[0101] The initial setting temperature may be lower than the heating temperature of step 2). For example, the initial setting temperature may be a temperature that is 80% of the heating temperature of step 2) or lower (i.e., the upper limit of the initial setting temperature may be a temperature that is 80% of the heating temperature), and the lower limit may be a temperature that is 20% of the heating temperature of step 2). In other words, if the initial setting temperature is T i , the heating temperature of step 2) is T ii , then it can be T i =0.2T ii ~0.9T ii , for example, it can be T i =0.3T ii ~0.9Tii , 0.4T ii ~0.75T ii , 0.35T ii ~0.7T ii , or 0.4T ii ~0.7T ii etc. Or it can be T i =0.2T ii ~0.6T ii , T i =0.3T ii ~0.6T ii , T i =0.3T ii ~0.5T ii wait.

[0102] Although it is just one example, the initial setting temperature (e.g., the chamber temperature condition set as the initial setting temperature) may be 50 to 100° C., for example, 50 to 90° C., 50 to 85° C., 55 to 85° C., or 55 to 80° C., etc. In addition, the treatment time of the wooden material at the initial setting temperature may typically be 1 to 120 hours, for example, 4 to 72 hours, 6 to 60 hours, 10 to 60 hours, 20 to 60 hours, 35 to 60 hours, or 40 to 60 hours, etc.

[0103] As an example of the treatment regarding the initial set temperature, the production method of the present invention may further include, between step 1) and step 2), a step of temporarily heating the wood material after the furan derivative resinification solution has been infiltrated at 50 to 100° C., 50 to 90° C., 50 to 85° C., 55 to 85° C., 55 to 80° C., or 50 to 70° C.

[0104] In a preferred embodiment, the method for producing a furan derivative resin solution containing 5-HMF as a furan derivative does not provide the above-mentioned "initial setting temperature" to the "wood material after the solution has penetrated". For example, when using a furan derivative resin solution such as a 5-HMF resin solution, the furan derivative resin solution such as the 5-HMF resin solution that has penetrated into the wood material can be heated to a desired temperature (i.e., the heating temperature of step 2)) without being subjected to the "initial setting temperature". In the production of a furan derivative resin solution such as a 5-HMF resin solution, it can be said that the desired modified wood material can be obtained without performing the "initial setting temperature". In contrast, in the method for producing a furan derivative resin solution containing 5-HMF as a furan derivative, even if the initial setting temperature is not performed in the production process, it is easy to provide good anti-swelling ability (ASE) and at least one property selected from the group consisting of bending strength, compressive strength and hardness.

[0105] As one example, after the 5-HMF resin solution containing 5-HMF and / or its derivatives and an inorganic salt that promotes the polymerization thereof is infiltrated into the wood material, the heating in step 2) may be performed without maintaining the temperature condition lower than the desired heating temperature in step 2) (for example, the low temperature condition is not maintained during the above-mentioned "time for performing the treatment of the wood material at the initial set temperature").

[0106] [Solution of the present invention]

[0107] The solution of the present invention is a furan derivative resin solution suitable for use in the above-mentioned production method. That is, the solution of the present invention is a furan derivative resin solution, which is a solution for modifying wood materials.

[0108] The furan derivative resin solution contains a furan derivative and an agent that promotes polymerization of at least a portion of the furan derivative and / or adhesion to a wood material. If desired, the furan derivative resin solution may contain an inorganic salt that inhibits polymerization of the furan derivative at room temperature in order to further improve the stability of the furan derivative in the solution.

[0109] As described above, the solution preferably contains one or two salts as solute components other than the furan derivative. That is, the furan derivative resin solution of the present invention contains "an inorganic salt that promotes polymerization of the furan derivative and / or adhesion to the wood material", and may further contain "an inorganic salt that inhibits polymerization of the furan derivative at room temperature" as desired. The solution is a better modification treatment solution for wood materials. For example, by using the solution of the present invention for modification treatment of wood materials, better anti-swelling ability (ASE) and at least one property selected from bending strength, compressive strength and hardness can be imparted to the wood materials.

[0110] In a preferred embodiment, the concentration of the "inorganic salt that promotes polymerization of furan derivatives and / or adhesion to wood materials" in the solution of the present invention can be 0.001 to 0.1 mol relative to 1 mol of the furan derivative in the solution. In addition, the concentration of the "inorganic salt that inhibits polymerization of 5-MHF at room temperature" that can be included as desired can be 0.0001 to 0.004 mol relative to 1 mol of the furan derivative in the solution.

[0111] In a preferred embodiment, the content or concentration of the "inorganic substance containing an inorganic salt that inhibits the polymerization of furan derivatives at room temperature" that can be contained in the solution of the present invention as desired can be less than or lower than the content or concentration of the "inorganic salt that promotes the polymerization of furan derivatives and / or adhesion to wood materials". More specifically, in the furan derivative resinization solution, the mol amount of the "inorganic substance containing an inorganic salt that inhibits the polymerization of furan derivatives at room temperature" relative to 1 mol of the furan derivative in the solution can be less than the mol amount of the "inorganic salt that promotes the polymerization of furan derivatives and / or adhesion to wood materials" relative to 1 mol of the furan derivative in the solution. If the contents of the two inorganic salts have such a relative relationship, it is easy to form a better modified treatment solution, and by using it for the modification treatment of wood materials, it is easy to give the wood materials better anti-swelling ability (ASE) and at least one property selected from bending strength, compressive strength and hardness.

[0112] The furan derivative resin solution of the present invention preferably has at least the characteristic of high stability. Therefore, even when the solution is stored for a long period of time and under severe conditions in a manner that does not contain "inorganic substances including inorganic salts that inhibit polymerization of furan derivatives at room temperature" (for example, even when it takes time from solution preparation to solution use as assumed in actual production, etc., or under an environment where temperature changes drastically), it is easy to suppress unintended polymerization of the furan derivative, and the furan derivative resin solution can be used in a more preferred state during the modification treatment. For example, the furan derivative resin solution of the present invention preferably does not cause turbidity, insolubility, and / or separation in the solution even after 7 days at room temperature (more preferably 14 days at room temperature, and even more preferably 1 month at room temperature) after its preparation (that is, at least at the time point immediately after the 7 days or 14 days, the solution does not cause turbidity, insolubility, and / or separation. For example, it can be determined at least visually that the solution does not cause turbidity, insolubility, and / or separation).

[0113] From the perspective of industrial or practical processing and manufacturing, a furan derivative resin solution with high stability is particularly useful. This is because even when the modified wood material is mass-produced, the variation in the properties of the obtained modified product can be better suppressed. For example, it is easy to avoid the unexpected phenomenon that the product is difficult to market due to large variations in anti-swelling ability (ASE) and bending strength, compression strength and hardness between batches.

[0114] The details and other matters such as more specific aspects of the furan derivative resinification solution of the present invention have been described in the above-mentioned [Production Method of the Present Invention], and therefore, description thereof will be omitted here to avoid repetition.

[0115] [Modified wood material of the present invention]

[0116] The modified wood material of the present invention is a modified wood material obtained by the above-mentioned production method. That is, the modified wood material of the present invention is a wood material modified by the above-mentioned production method and containing at least a polymerized or attached furan derivative.

[0117] More specifically, the modified wood material of the present invention is a wood material modified using "a furan derivative resin solution containing a furan derivative and an inorganic salt that promotes polymerization of the furan derivative and / or adhesion to the wood material". Therefore, it contains at least a furan resin formed by polymerization of a furan derivative or a furan derivative attached to the wood material, and in a preferred case, it may contain a substance derived from the above-mentioned inorganic salt used as a raw material. It should be noted that the resin formed by polymerization is not limited to the category of polymers, and may at least partially contain a resin belonging to the category of oligomers.

[0118] In addition, in the case of a wood material modified using a furan derivative resinizing solution that further contains "an inorganic substance containing an inorganic salt that inhibits the polymerization of a furan derivative at room temperature" which may be contained as desired, in addition to the above-mentioned substances, "an inorganic substance containing an inorganic salt that inhibits the polymerization of a furan derivative at room temperature", substances derived therefrom, etc. may be contained.

[0119] In a preferred embodiment, the modified wood material of the present invention can exhibit at least one of the following physical properties.

[0120] (Anti-swelling ability / ASE)

[0121] 50% or more, such as 50-95%, 50-80%, 50-70%, 50-65%, or 50-60% anti-swelling ability (ASE)

[0122] Anti-swelling ability (ASE) (%) = [(S c -S t ) / S c ]×100··Formula (3)

[0123] (Where S t S is the cross-sectional area swelling ratio (%) of the modified material when it absorbs moisture or water under fixed conditions from a completely dry state, c It is the cross-sectional area swelling ratio (%) of the material before modification (or non-modified wood material) when it absorbs moisture or water under fixed conditions from a completely dry state under the same conditions as the modified wood.

[0124] The anti-swelling ability ASE is an index showing dimensional stability. If the ASE is 50% or more, the modified wood material is preferred for practical use, while if it is less than 50%, it is unsuitable or unacceptable for practical use.

[0125] It should be noted that "completely dry" / "completely dry state" in this specification refers to the state of the material when the modified material or the non-modified material is placed in a thermostat (manufactured by Yamato Scientific Co., Ltd., model: DN43) set at 105° C. until there is no weight change. In addition, the completely dry weight refers to the weight of the material when there is no weight change.

[0126] (Bending Strength)

[0127] The flexural strength is the maximum stress value when performing a flexural test with reference to "JIS Z 2101 Testing methods for wood", that is, the maximum stress value obtained when performing a flexural test using a "center load method" in which a load is applied to the center between fulcrums using a testing machine that can record load and displacement (e.g., Shimadzu Autograph, EZ TEST).

[0128] Relative to the non-modified wood material, the increase is 5% or more, for example 7% or more or 10% or more, or 5-70%, 5-60%, 5-50%, 5-40%, 5-30%, 5-20%, 5-15%, 7-70%, 7-60%, 7-50%, 7-40%, 7-30%, 7-20%, 7-15%, etc.

[0129] In the production method using a furan derivative resinified solution containing 5-HMF as the furan derivative, good anti-swelling ability (ASE) and at least one property selected from flexural strength, compressive strength and hardness can be easily imparted in the production process.

[0130] In a preferred embodiment, the modified wood material of the present invention can be a wood material used in floor materials, decks (such as wooden decks), exterior wall materials, shutters, furniture, truck bodies, wooden fences, guardrails, residential exterior building materials and / or musical instruments.

[0131] The modified wood material of the present invention has the above-mentioned preferred characteristics, so it is not limited to indoor use, but is also particularly suitable for use as wood for outdoor use. Therefore, it can be said that the present invention is also conducive to providing new uses and added value for coniferous trees (such as Japanese coniferous trees).

[0132] Other specific matters such as more aspects related to the modified wood material of the present invention have been directly or indirectly described in the above-mentioned [Production method of the present invention] and [Solution of the present invention], and therefore, the description thereof will be omitted here to avoid repetition.

[0133] Although one embodiment of the present invention has been described above, this is only a typical example, and therefore, the present invention is not limited to these descriptions, and it can be easily understood by those skilled in the art that there are various forms and modifications.

[0134] For example, the effects described in the specification of the present application are merely examples, and the present invention is not necessarily limited to these effects, and may also have additional effects.

[0135] In addition, for example, although the furan derivative resinizing solution described in the present invention is a solution containing a furan derivative and an inorganic salt that promotes the polymerization of the furan derivative, the presence of components (e.g., trace or extremely trace components, which can be recognized as trace or extremely trace components by those skilled in the art) that are inevitably or accidentally mixed into the solution during preparation, storage and / or use of the solution is acceptable.

[0136] It should be noted that the present invention described above includes the following aspects for confirmation.

[0137] Method 1:

[0138] A manufacturing method is a manufacturing method of a modified wood material, comprising the following steps:

[0139] 1) a step of infiltrating a 5-HMF resin solution into a wood material, wherein the 5-HMF resin solution contains 5-hydroxymethylfurfural (5-HMF) and an inorganic salt and / or a hydrate or anhydride thereof and / or an organic acid and / or an anhydride or salt thereof that promotes polymerization of at least a portion of 5-HMF and / or adhesion to the wood material; and

[0140] 2) A step of polymerizing at least a portion of 5-HMF in the infiltrated 5-HMF resinified solution in a wood material and / or causing it to adhere to the wood material.

[0141] · Second aspect: The production method according to the first aspect, wherein the solvent in the 5-HMF resinification solution is an aqueous medium.

[0142] A third aspect: The production method according to any one of the first aspect or the second aspect, wherein the inorganic salt that promotes polymerization of at least a portion of 5-HMF and / or adhesion to the wood material is an inorganic salt composed of anions of chloride ions and / or sulfate ions and cations of ammonium ions, magnesium ions and / or hydrogen ions.

[0143] · A fourth aspect: The production method according to any one of the first to third aspects, wherein the concentration of the inorganic salt that promotes polymerization of 5-HMF and / or adhesion to the wood material is 0.001 to 0.1 mol per 1 mol of 5-HMF.

[0144] ·A fifth aspect: A production method according to any one of the first aspect or the second aspect, wherein the organic acid and / or its anhydride / salt that promotes the polymerization of at least a portion of 5-HMF and / or its adhesion to the wood material is one or more of one or more organic acids and / or its anhydrides / acids that can be formed selected from saturated or unsaturated aliphatic hydrocarbons and saturated or unsaturated aromatic hydrocarbons, wherein the saturated or unsaturated aliphatic hydrocarbon is substituted with at least one functional group selected from hydrogen, halogen, alkyl, formyl, hydroxyl and hydroxyalkyl, has one or more carboxyl and / or sulfonic groups and has 1 to 20, 1 to 6 or 1 to 4 carbon atoms, and the saturated or unsaturated aromatic hydrocarbon is substituted with at least one functional group selected from hydrogen, halogen, alkyl, formyl, hydroxyl and hydroxyalkyl, has one or more carboxyl and / or sulfonic groups and has 3 to 20, 3 to 18 or 6 to 12 carbon atoms.

[0145] · A sixth aspect: The production method according to the fifth aspect, wherein the concentration of the organic acid and / or its anhydride or salt that promotes polymerization of 5-HMF and / or adhesion to the wood material is 0.001 to 0.1 mol per 1 mol of 5-HMF.

[0146] · A seventh aspect: The production method according to any one of the first to sixth aspects, wherein step 1) is performed under a reduced pressure lower than atmospheric pressure.

[0147] ·Aspect 8: The production method according to any one of aspects 1 to 7, wherein step 2) is performed at 5 to 180°C.

[0148] ·9th method:

[0149] The production method according to any one of the first to eighth aspects, wherein the wood material is a coniferous tree material.

[0150] · A tenth aspect: The production method according to any one of the first to ninth aspects, wherein the wood material is a Japanese cedar or a cypress.

[0151] · Eleventh aspect: The production method according to any one of the first aspect to the tenth aspect, wherein the concentration of 5-HMF in the 5-HMF resinized solution is 5 to 50 wt % (excluding 50 wt %) based on the entire 5-HMF resinized solution.

[0152] Method 12:

[0153] A 5-HMF resin solution is a 5-HMF resin solution used for modifying wood materials.

[0154] The present invention contains 5-HMF and an inorganic salt which promotes the polymerization of 5-HMF in a wood material and / or the adhesion of 5-HMF to the wood material.

[0155] · A 13th aspect: The 5-HMF resinification solution according to the 12th aspect, wherein the solvent in the 5-HMF resinification solution is an aqueous medium.

[0156] A fourteenth aspect: A modified wood material, which is a wood material modified by the production method according to any one of claims 1 to 11, comprising at least polymerized 5-HMF.

[0157] A fifteenth aspect: The modified wooden material according to the fourteenth aspect, wherein the wooden material is a wooden material used for floor materials, decks, exterior wall materials, blinds, furniture, truck bodies, wooden fences, guardrails, residential exterior building materials, and / or musical instruments.

[0158] Example

[0159] [Study on accelerator]

[0160] In a 5-HMF resinizing solution containing 30 wt % 5-HMF, 0.01 mol of various accelerators per 1 mol of 5-HMF, and water, a rectangular cedar sapwood (30 mm×30 mm×5 mm) was immersed at room temperature under a reduced pressure of 50 hPa or less for 2 hours, then returned to normal pressure and immersed in the resinizing solution for 24 hours.

[0161] Then, the cedar rectangular parallelepiped sapwood was taken out from the 5-HMF resin solution, dried and reacted at 80°C for 3 hours and at 105°C for 8 hours under atmospheric pressure to prepare a 5-HMF resin sample.

[0162] Table 1 shows the anti-swelling ability (ASE) calculated for the 5-HMF resin samples prepared using various accelerators.

[0163] [Table 1]

[0164] Accelerator Anti-swelling ability (ASE) Ammonium chloride 90.3 Magnesium chloride hexahydrate 91.0 Ammonium sulfate 90.3 Ammonium bisulfate 93.8 Maleic acid 92.0 Citric Acid 89.9

[0165] It is clear from the results in Table 1 that various inorganic salts and hydrates thereof and organic acids promote the resinification of 5-HMF in wood materials and impart significantly excellent anti-swelling ability to wood materials. Specifically, it is shown that inorganic salts selected from ammonium chloride, magnesium chloride hexahydrate, ammonium sulfate and ammonium hydrogen sulfate and organic acids selected from maleic acid and citric acid promote the polymerization of at least a part of 5-HMF and / or its adhesion to wood materials, and impart anti-swelling ability to wood materials.

[0166] [Study on 5-HMF concentration]

[0167] Rectangular sapwood (30 mm × 30 mm × 5 mm) of Japanese cedar and Japanese cypress were immersed in a 5-HMF resinizing solution containing 5 to 30 wt% of 5-HMF, 0.01 mol of ammonium hydrogen sulfate per 1 mol of 5-HMF, and water at room temperature under reduced pressure of 50 hPa or less for 2 hours, then returned to normal pressure and immersed in the resinizing solution for 24 hours.

[0168] Then, the cedar rectangular parallelepiped sapwood was taken out from the 5-HMF resin solution, dried and reacted at 80°C for 3 hours and at 105°C for 8 hours under atmospheric pressure to prepare a 5-HMF resin sample.

[0169] Table 2 shows the anti-swelling ability (ASE) calculated for the 5-HMF resinized samples prepared using the 5-HMF resinized solutions having various concentrations.

[0170] [Table 2]

[0171]

[0172] The results in Table 2 show that the concentration of 5-HMF in the resinification solution in the range of 5 to 50% by weight promotes the resinification of the wood material and imparts significantly excellent anti-swelling ability to the wood material.

[0173] [Study on reaction temperature 1]

[0174] Rectangular sapwood (30 mm×30 mm×5 mm) of Japanese cedar and Japanese cypress were immersed in a 5-HMF resinizing solution containing 20 wt% of 5-HMF, 0.01 mol of ammonium hydrogen sulfate per 1 mol of 5-HMF, and water at room temperature under reduced pressure of 50 hPa or less for 2 hours, then returned to normal pressure and immersed in the resinizing solution for 24 hours.

[0175] Then, the cedar rectangular parallelepiped sapwood was taken out from the 5-HMF resin solution, dried and reacted at 80° C. for 3 hours and dried and reacted at 105° C. for 8 hours under atmospheric pressure to prepare a 5-HMF resin sample.

[0176] Table 3 shows the anti-swelling ability (ASE) calculated for the 5-HMF resin samples prepared at various reaction temperatures.

[0177] [Table 3]

[0178]

[0179] The results in Table 3 show that the resinification of wood materials is promoted in the reaction temperature range of at least 80 to 140°C, and significantly excellent anti-swelling ability is imparted to the wood materials. In addition, it is shown that the lower the reaction temperature, the higher the anti-swelling ability (ASE) of the 5-HMF resinified sample tends to be, so the resinification of wood materials using 5-HMF can achieve the purpose even at a low reaction temperature. In addition, it is shown that significantly excellent anti-swelling ability is imparted to wood materials even at a high reaction temperature, but considering safety, it is preferred to set the reaction temperature to 180°C or less.

[0180] [Study of reaction temperature 2]

[0181] Since the tendency of the lower the reaction temperature, the higher the anti-swelling ability (ASE), the 5-HMF resin sample was prepared under the same conditions as [Study of Reaction Temperature 1] except that the reaction temperature was set to 20°C and the cedar rectangular sapwood was used, and the anti-swelling ability (ASE) thereof was calculated. The anti-swelling ability (ASE) calculated for the 5-HMF resin sample prepared by reaction at 20°C is shown in Table 4.

[0182] [Table 4]

[0183] Species of wood material Reaction temperature (℃) Anti-swelling ability (ASE) Cryptomeria fortunei 20 98.8

[0184] The results in Table 4 show that the resinification of the wood material is promoted even at a reaction temperature of 20° C., and a significantly excellent anti-swelling ability is imparted to the wood material. In addition, it is shown that since the lower the reaction temperature, the higher the anti-swelling ability (ASE) is, the purpose can be achieved at a reaction temperature within a range where the 5-HMF resinification solution does not freeze, for example, at a reaction temperature of 5° C. or higher.

[0185] Industrial Applicability

[0186] The technology of the present invention can be used for modification of wood materials. For example, by modifying wood materials, wood materials can be made more suitable for outdoor use. Therefore, the present invention can be well used not only for interior materials such as furniture and wooden floors, but also for exterior building materials of houses such as wooden decks, especially for outdoor use.

Claims

1. A manufacturing method is a manufacturing method of a modified wood material, comprising the following steps: 1) a step of allowing a 5-HMF resin solution to penetrate into a wood material, wherein the 5-HMF resin solution contains 5-hydroxymethylfurfural (5-HMF) and an inorganic salt and / or a hydrate or anhydride thereof and / or an organic acid and / or an anhydride or salt thereof that promotes polymerization of at least a portion of the 5-HMF and / or adhesion to the wood material; and 2) A step of polymerizing at least a portion of 5-HMF in the infiltrated 5-HMF resinified solution in a wood material and / or causing it to adhere to the wood material.

2. The manufacturing method according to claim 1, wherein: The solvent in the 5-HMF resinification solution is an aqueous medium.

3. The manufacturing method according to any one of claims 1 or 2, wherein The inorganic salt that promotes polymerization of at least a portion of 5-HMF and / or adhesion to the wood material is an inorganic salt composed of anions of chloride ions and / or sulfate ions and cations of ammonium ions, magnesium ions, and / or hydrogen ions.

4. The production method according to any one of claims 1 to 3, wherein The concentration of the inorganic salt that promotes the polymerization of 5-HMF and / or the adhesion to the wood material is 0.001 to 0.1 mol per 1 mol of 5-HMF.

5. The manufacturing method according to any one of claims 1 or 2, wherein: The organic acid and / or its anhydride / salt that promotes the polymerization of at least a part of 5-HMF and / or its attachment to the wood material is one or more organic acids and / or their anhydrides / acids that can be formed selected from one or more organic acids selected from saturated or unsaturated aliphatic hydrocarbons and saturated or unsaturated aromatic hydrocarbons; the saturated or unsaturated aliphatic hydrocarbon is substituted with at least one functional group selected from hydrogen, halogen, alkyl, formyl, hydroxyl and hydroxyalkyl, has one or more carboxyl and / or sulfonic groups and has 1 to 20, 1 to 6 or 1 to 4 carbon atoms; the saturated or unsaturated aromatic hydrocarbon is substituted with at least one functional group selected from hydrogen, halogen, alkyl, formyl, hydroxyl and hydroxyalkyl, has one or more carboxyl and / or sulfonic groups and has 3 to 20, 3 to 18 or 6 to 12 carbon atoms.

6. The manufacturing method according to claim 5, wherein: The concentration of the organic acid and / or its anhydride or salt that can be formed, which promotes the polymerization of 5-HMF and / or its adhesion to the wood material, is 0.001 to 0.1 mol per 1 mol of 5-HMF.

7. The production method according to any one of claims 1 to 6, wherein The step 1) is carried out under reduced pressure less than atmospheric pressure.

8. The production method according to any one of claims 1 to 7, wherein Step 2) is performed at 5 to 180°C.

9. The production method according to any one of claims 1 to 8, wherein The wood material is coniferous wood.

10. The production method according to any one of claims 1 to 9, wherein: The wood material is cedar or cypress.

11. The production method according to any one of claims 1 to 10, wherein The concentration of 5-HMF in the 5-HMF resinized solution is 5 to 50% by weight based on the entire 5-HMF resinized solution, excluding 50% by weight.

12. A 5-HMF resin solution, which is a 5-HMF resin solution for modifying wood materials. Contains 5-HMF and an inorganic salt that promotes polymerization of 5-HMF in a wood material and / or adhesion to the wood material.

13. The 5-HMF resinification solution according to claim 12, wherein The solvent in the 5-HMF resinification solution is an aqueous medium.

14. A modified wood material, which is a wood material modified by the production method according to any one of claims 1 to 11, comprising at least polymerized 5-HMF.

15. The modified wood material according to claim 14, wherein Wood materials are wood materials used in flooring materials, decks, exterior siding materials, shutters, furniture, truck bodies, wood fences, guardrails, residential exterior building materials, and / or musical instruments.

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