Wood treatment agent, as well as treated wood and production method thereof

Abstract

To provide a water-based wood treatment agent capable of imparting good weather resistance, as well as treated wood and a production method thereof.SOLUTION: A wood treatment agent containing a high-ortho resol-phenolic resin is impregnated or applied to wood and heat treated to produce treated wood.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a wood treatment agent, a treated wood, and a method for producing the same. [Background technology]

[0002] Phenolic resins are used as wood treatment agents to improve the durability of wood. For example, Patent Document 1 describes the production of wooden exterior materials using modified wood impregnated with bisphenol A-formaldehyde resin. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-327803 Summary of the Invention [Problem to be solved by the invention]

[0004] However, bisphenol A-formaldehyde resins have low water dilutability, and when used as wood treatment agents, an organic solvent such as alcohol must be added. These solvent-based wood treatment agents have a greater environmental impact than water-based (non-solvent-based) wood treatment agents and are inferior in terms of ease of handling and cost.

[0005] On the other hand, conventional water-soluble phenolic resins are random resol phenolic resins, which are easily converted to triphenylmethane structures by oxidation when exposed to ultraviolet light. Wood treated with such phenolic resins shows significant color change due to aging immediately after treatment in outdoor environments exposed to sunlight, and its weather resistance is not sufficient.

[0006] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an aqueous wood treatment agent that can impart good weather resistance, as well as treated wood and a method for producing the same. [Means for solving the problem]

[0007] The present invention is based on the discovery that high-ortho resol phenolic resins can exhibit excellent weather resistance as aqueous wood treatment agents.

[0008] The present invention provides the following means. [1] A wood treatment agent containing a high-ortho resole phenolic resin. [2] The wood treatment agent according to [1], wherein the high-ortho resol phenolic resin is water-soluble. [3] The wood treatment agent according to [1] or [2], wherein the high-ortho resol phenolic resin has a weight-average molecular weight of 100 to 8,000. [4] The wood treatment agent according to any one of [1] to [3], having a viscosity at 25°C of 1 to 3000 mPa·s. [5] A wood treatment agent according to any one of [1] to [4], having a pH of 5.0 to 10.0. [6] A wood treatment agent according to any one of [1] to [5], which is a coating agent or an impregnation agent.

[0009] [7] Treated wood having a high-ortho resole phenolic resin in at least a portion of the interior or surface of the wood. [8] Treated wood that has been treated with any one of the wood treatment agents described in [1] to [6] and has a high-ortho resol phenolic resin in at least a portion of the interior or surface of the wood.

[0010] [9] A method for producing treated wood, comprising impregnating or coating wood with any one of the wood treatment agents described in [1] to [6], and then heat treating the wood. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide an aqueous wood treatment agent, and to provide treated wood having good weather resistance using the wood treatment agent, and a method for producing the same. DETAILED DESCRIPTION OF THE INVENTION

[0012] The definitions and meanings of terms and notations used in this specification are as follows. The expression "X to Y" (X and Y are numerical values) means a numerical range with X as the lower limit and Y as the upper limit. In a numerical range (e.g., a range of content, etc.), the lower limit and upper limit values ​​described in stages may be combined independently. The lower limit and upper limit values ​​of a numerical range may be replaced with numerical values ​​described in the examples. The term "water-solubility" refers to the property of dissolving in water to form a uniform aqueous solution, and is used in a qualitative sense. The water dilutability refers to the miscibility defined in JIS K 6910:2007, and is the amount of water required to add to a phenolic resin to cause abnormalities such as turbidity or precipitation, expressed as a mass fraction. Specifically, it can be determined by the method described in the examples. The weight-average molecular weight is a polystyrene-equivalent molecular weight determined by gel permeation chromatography (GPC) based on a calibration curve prepared using standard polystyrene samples. Specifically, it is determined by the method described in the Examples. The viscosity is a value measured with an E-type viscometer at 25° C. Specifically, it can be determined by the method described in the examples.

[0013] [Wood treatment agent] A wood treating agent according to an embodiment of the present invention (hereinafter referred to as the present embodiment) contains a high-ortho resol phenolic resin. By using a high-ortho resol phenolic resin as a wood treatment agent, it is possible to impart good weather resistance to wood as an aqueous wood treatment agent, and it is also possible to impart strength to wood.

[0014] When wood is exposed to sunlight, particularly ultraviolet light, lignin leaching occurs over time. When exposed to wind, rain, etc., dust, soil, etc. adhere to the leached lignin areas, black stains appear on the wood, causing deterioration. Treating wood with random resol phenolic resin can suppress lignin leaching, but the color of the wood changes significantly due to the oxidation reaction of the resin itself. In contrast, we have found that high-ortho resol phenolic resins are less likely to change to the triphenylmethane structure that causes color changes, and are effective in suppressing color changes caused by aging of wood in outdoor environments and improving the weather resistance of wood.

[0015] High-ortho resol phenolic resin has excellent affinity with water, making it easy to impregnate or apply evenly to wood, and providing good weather resistance.

[0016] The wood treatment agent of this embodiment may contain water, may be in a state in which the high-ortho resol phenolic resin is dispersed in water, or may be an aqueous solution from the viewpoint of facilitating even impregnation or application to wood. The high-ortho resol phenolic resin is preferably water-soluble so that it can be used as a homogeneous wood treatment agent and can be easily impregnated or applied to wood evenly.

[0017] From the viewpoint of providing a wood treatment agent that is easily water-soluble and easy to impregnate or apply, the high-ortho resol phenolic resin preferably has a water dilutability of 100% or more, more preferably 500% or more, even more preferably 1000% or more, even more preferably 2000% or more, and particularly preferably 4000% or more.

[0018] When the high-ortho resol phenolic resin is in the form of an aqueous solution, the solids concentration is preferably 20 to 80 mass%, more preferably 30 to 70 mass%, even more preferably 40 to 60 mass%, and even more preferably 45 to 55 mass%, from the viewpoint of making it a wood treatment agent that is easy to impregnate or apply.

[0019] When the high-ortho resole phenolic resin is in the form of an aqueous solution, the viscosity at room temperature (25°C) is preferably 1 to 3000 mPa·s, more preferably 1 to 2000 mPa·s, even more preferably 3 to 1000 mPa·s, and even more preferably 3 to 500 mPa·s, from the viewpoint of making it an easy-to-impregnate or apply wood treatment agent.

[0020] When the high-ortho resol phenolic resin is in the form of an aqueous solution, the pH is preferably 5.0 to 10.0, more preferably 6.5 to 9.5, and even more preferably 7.0 to 9.0, from the viewpoints of storage stability of the wood treatment agent, prevention of degeneration of the wood to be treated, and safety during handling.

[0021] The high-ortho resol phenolic resin preferably has a weight average molecular weight of 100 to 8,000, more preferably 200 to 5,000, and even more preferably 300 to 2,000, from the viewpoint of good water solubility and ease of impregnation or application as a wood treatment agent.

[0022] From the viewpoint of ease of impregnation or application to wood, the viscosity of the wood treatment agent of this embodiment at room temperature (25°C) is preferably 1 to 3000 mPa·s, more preferably 1 to 2000 mPa·s, even more preferably 3 to 1000 mPa·s, and even more preferably 3 to 500 mPa·s.

[0023] The pH of the wood treatment agent of this embodiment is preferably 5.0 to 10.0, more preferably 6.5 to 9.5, and even more preferably 7.0 to 9.0, from the viewpoints of storage stability of the treatment agent, prevention of degeneration of the wood to be treated, and safety during handling.

[0024] The wood treatment agent of this embodiment is preferably applied to wood as a coating agent or impregnation agent. From the viewpoints of ease of impregnation or application to wood and an effective application amount, the concentration of the high-ortho resol phenolic resin in the wood treatment agent is preferably 5 to 70 mass%, more preferably 10 to 60 mass%, even more preferably 15 to 55 mass%, and even more preferably 20 to 50 mass%.

[0025] The high-ortho resole phenolic resin in the wood treatment agent is preferably uniformly diluted with water or an organic solvent to the above concentration, more preferably diluted with water. By diluting the high-ortho resole phenolic resin with water or an organic solvent, it can be made to have an appropriate viscosity that is easy to handle. The content of water or organic solvent in the wood treatment agent is preferably 30 to 95 mass %, more preferably 40 to 90 mass %, even more preferably 45 to 85 mass %, and even more preferably 50 to 80 mass %.

[0026] The wood treatment agent of this embodiment may contain other components in addition to the high-ortho resol phenolic resin and water or organic solvent. As the other components, additives that can be contained in known wood treatment agents can be appropriately used. The total content of other components in the wood treatment agent is preferably 10% by mass or less, more preferably 8% by mass or less, and even more preferably 5% by mass or less, so as not to impair the effects of the present invention.

[0027] Examples of the additives include hardening accelerators, bulking agents, reducing sugars, thickeners, viscosity adjusters, and flame retardants.

[0028] Specific examples of the hardening accelerator include alkali metal carbonates such as sodium carbonate, sodium hydrogen carbonate, potassium carbonate, and potassium hydrogen carbonate, and organic hardening accelerators such as resorcinol.

[0029] Specific examples of the extender include alkaline earth metal carbonates such as calcium carbonate, and organic fillers such as wood flour, walnut flour, lignin, tannin, and blood powder.

[0030] The reducing sugar reduces the amount of formaldehyde emitted during curing of the high-ortho resol phenolic resin and lightens the color of the cured product. The reducing sugar may be, for example, a monosaccharide, an oligosaccharide (disaccharide to decasaccharide), or a dextrin (including maltodextrin). Specific examples of monosaccharides include glucose, fructose, mannose, galactose, ribose, and xylose. Specific examples of oligosaccharides include disaccharides such as maltose, lactose, and isomaltose; trisaccharides such as maltotriose; and tetrasaccharides or more such as maltooligosaccharides, isomaltooligosaccharides, fructooligosaccharides, mannooligosaccharides, and galactooligosaccharides.

[0031] Specific examples of thickeners include wheat flour, polysaccharides such as sodium carboxymethyl cellulose, and polymer compounds such as acrylic resins.

[0032] Specific examples of viscosity modifiers include high-boiling water-soluble organic solvents such as glycerin, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, hexylene glycol, and phenoxyethanol.

[0033] Specific examples of flame retardants include halogen-based flame retardants such as brominated aromatic compounds, phosphorus-based flame retardants such as phosphate ester compounds, inorganic flame retardants such as aluminum hydroxide, nitrogen-containing compound-based flame retardants such as guanidine compounds, silicon-based flame retardants, and halogen-based flame retardants such as antimony oxide.

[0034] Furthermore, as other components, pigments such as coloring pigments and dyes may be contained for the purpose of imparting design features to the wood. In wood treatment agents, phosphite esters such as triphenyl phosphite are sometimes added to prevent the oxidation of phenolic resins and thereby lighten their color. However, in the wood treatment agent of this embodiment, the use of phosphite esters is not preferred because they have poor miscibility with high-ortho resole phenolic resins, poor water dilutability, and the precipitation of solids makes it difficult to obtain a uniform wood treatment agent.

[0035] The wood treatment agent of this embodiment can be obtained by stirring and mixing a high-ortho resol phenolic resin, water, an organic solvent, and other components that are added as needed.

[0036] High-ortho resol phenolic resins can be produced by known synthesis methods, for example, by addition condensation of phenols and aldehydes in the presence of an alkali catalyst, which is a divalent metal salt.

[0037] Phenols are compounds having a structure in which at least one hydroxyl group is bonded to an aromatic ring, and the aromatic ring may be monocyclic or condensed polycyclic, and may have a substituent such as an alkyl group. Specific examples of phenols include phenol; alkylphenols such as o-, m-, or p-cresol, o-, m-, or p-ethylphenol, and various isomers of xylenol; and α- or β-naphthol. Other examples include cardanol and cashew nut shell liquid. Phenols may be used alone or in combination of two or more. Among these, phenol is preferred from the viewpoint of good reactivity, etc.

[0038] The aldehyde is at least one compound selected from the group consisting of compounds having a formyl group and polymers thereof. Specific examples of the aldehyde include formaldehyde, paraformaldehyde, acetaldehyde, propylaldehyde, benzaldehyde, salicylaldehyde, glyoxal, etc. The aldehyde may be used alone or in combination of two or more. Among these, formaldehyde and paraformaldehyde are preferred from the viewpoint of good reactivity, etc.

[0039] The amounts of phenols and aldehydes used in the synthesis of high-ortho resol phenolic resins are such that the molar ratio (F / P) of aldehydes (F) to phenols (P) is preferably 1.0 to 4.0, more preferably 1.5 to 3.8, and even more preferably 1.7 to 3.5, from the viewpoint of suppressing the elution of unreacted phenols from wood treated with a wood treatment agent and the volatilization of unreacted aldehydes. When the aldehyde is a polymer such as paraformaldehyde, F / P is the value converted into the monomer.

[0040] As the alkali catalyst used in the synthesis of the high-ortho resol phenolic resin, a divalent metal salt is preferred. Various alkali catalysts are used in the synthesis of resol phenolic resins, but with organic alkali catalysts such as tetramethylammonium hydroxide, the position of addition of aldehydes to the phenol skeleton tends to be para-oriented, while with monovalent metal hydroxide catalysts such as sodium hydroxide, the position of addition of aldehydes to the phenol skeleton tends to be random. In contrast, by using a divalent metal salt, a resol phenolic resin with high ortho orientation can be obtained. The position (orientation) at which the aldehydes are added to the phenol skeleton is as follows: 13 This can be confirmed by C-NMR (nuclear magnetic resonance) analysis or FT-IR (Fourier transform infrared spectroscopy) analysis. Specifically, the ratio of ortho- to para-positions (o / p ratio) can be determined by the method described in the Examples.

[0041] Examples of divalent metal salts include compounds selected from the group consisting of hydroxides, oxides, chlorides, carbonates, sulfates, nitrates, and acetates of metals selected from the group consisting of magnesium, calcium, barium, manganese, zinc, lead, cadmium, and nickel. Specific examples of divalent metal salts include calcium hydroxide, barium hydroxide, and magnesium hydroxide. The divalent metal salts may be used alone or in combination of two or more. Of these, barium hydroxide is preferred.

[0042] The amount of the alkali catalyst, which is a divalent metal salt, used is preferably 0.1 to 50 parts by mass, more preferably 0.5 to 40 parts by mass, and even more preferably 1 to 30 parts by mass per 100 parts by mass of phenols, from the viewpoint of achieving a moderate reaction rate and controlling the weight-average molecular weight of the high-ortho resol phenolic resin.

[0043] The reaction conditions for the addition condensation of phenols and aldehydes using a divalent metal salt as a catalyst may be the same as those for the case where other alkali catalysts are used. From the viewpoint of obtaining a high-ortho resol phenolic resin having a desired weight-average molecular weight at a moderate reaction rate and in high yield, the reaction temperature is preferably 30 to 100°C, more preferably 50 to 90°C, and even more preferably 55 to 80°C. The reaction time can be adjusted appropriately depending on the reaction temperature. For example, when the reaction temperature is 60°C, the reaction time may be 3 to 8 hours.

[0044] After the phenols and aldehydes are reacted in the presence of an alkali catalyst, the reaction product may be subjected to treatment such as neutralization with an acid or dilution with water, if necessary. Acids used for neutralization include inorganic acids such as boric acid, sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, and sulfamic acid, and organic acids such as formic acid, oxalic acid, acetic acid, citric acid, lactic acid, sulfanilic acid, benzoic acid, phenolsulfonic acid, p-toluenesulfonic acid, methanesulfonic acid, and lauric acid. These acids may be used alone or in combination. The pH after neutralization is preferably 5.0 to 8.0, and more preferably 5.5 to 7.5.

[0045] [Treated wood] The treated wood of this embodiment contains a high-ortho resol phenolic resin at least partially inside or on the surface of the wood. Wood treated with such high-ortho resol phenolic resin has good weather resistance. The treated wood may contain high-ortho resol phenolic resin in part of its interior or surface, but by having it over a wide range in many parts of the treated wood, it can have good weather resistance overall.

[0046] The treated wood is preferably treated with the wood treating agent of the present embodiment described above. Treating wood with the wood treating agent of this embodiment makes it possible to obtain treated wood with good weather resistance.

[0047] [Manufacturing method of treated wood] The treated wood can be suitably obtained by the manufacturing method of this embodiment, in which the wood treating agent of this embodiment described above is impregnated into or applied to wood, and then heat-treated.

[0048] Examples of wood to be impregnated or coated with the wood treatment agent include solid wood and wood-based materials. Examples of solid wood include birch, paulownia, cedar, cypress, pine, Japanese cypress, sawara, and pine. The solid wood may be in the form of sawn lumber, planks, or the like. Examples of wood materials include plywood, glued laminated lumber, cross-laminated lumber, laminated veneer lumber, blockboard, veneer, and wood boards. Examples of wood boards include insulation board (IB), medium-density fiberboard (MDF), hardboard (HB), particle board, and oriented strand board (OSB).

[0049] In this embodiment, the wood to be treated can be selected arbitrarily depending on the intended use of the treated wood. Applications of the treated wood include building materials, furniture, woodwork, etc. The treated wood of this embodiment is useful, for example, in applications where it is used outdoors or exposed to outdoor environments, particularly where weather resistance is required.

[0050] The method for impregnating wood with a wood treatment agent is not particularly limited, and any known method can be used. Examples of impregnation methods include atmospheric pressure impregnation, reduced pressure impregnation, reduced pressure and pressure impregnation, pressure impregnation, impregnation and compaction, and ultrasonic impregnation. The impregnation method can be selected as desired depending on the type of wood and the intended use of the treated wood.

[0051] The method for applying the wood treatment agent to wood is not particularly limited, and known methods can be used. Examples of application methods include brushing, roller application, spraying, dipping, etc. The application method can be selected as desired depending on the type of wood and the intended use of the treated wood.

[0052] In the manufacturing method of this embodiment, wood impregnated with or coated with a wood treatment agent is heat-treated, which dries the wood and hardens the high-ortho resole phenolic resin in the wood treatment agent. In order to prevent a sudden thermal load on the wood and to promote moderate curing of the high-ortho resol phenolic resin, the heat treatment is carried out by gradually increasing the temperature to a maximum temperature of preferably 100 to 200° C., more preferably 110 to 190° C., and even more preferably 120 to 180° C. The holding time at the maximum temperature varies depending on the type and size of the wood, but is preferably 0.1 to 8 hours, more preferably 0.5 to 7 hours, and even more preferably 0.5 to 6 hours. [Example]

[0053] The present invention will be described in detail below with reference to examples. The present invention is not limited to the following examples, and various modifications are possible within the scope of the present invention.

[0054] [Synthesis of phenolic resin] The phenolic resins used in the Examples and Comparative Examples were synthesized. Various measurement methods for the following synthesis examples are shown below.

[0055] (phenolic resin concentration) A 1.5±0.1 g sample (phenolic resin aqueous solution) was placed on an aluminum foil dish (inner diameter 50 mm, height 15 mm) whose weight P had been measured in advance, and the sample weight (before drying) W1 was accurately weighed. The aluminum foil dish was placed in an incubator set at 135°C and dried for 60 minutes, after which it was allowed to cool in a desiccator. The weight of the aluminum foil dish after drying was measured at room temperature (25°C), and the weight P of the aluminum foil dish was subtracted to calculate the sample weight (after drying) W2. The sample after drying (the volatile residue on the aluminum foil dish) was considered to be phenolic resin, and the calculated value of W2 / W1 × 100 was used as the concentration of phenolic resin in the sample (mass%).

[0056] (water dilutable) The miscibility with pure water (water dilutability) was measured in accordance with the provisions of 5.5 of JIS K 6910: 2007. The mass of the sample used in calculating the miscibility was the mass of the resin solid content. In the miscibility measurement, if no abnormalities such as turbidity or precipitation were observed even after adding an amount of water equivalent to 4000% miscibility, the measurement was terminated at that point, and the water dilutability was determined to be over 4000%.

[0057] (viscosity) The viscosity of the sample (aqueous phenolic resin solution) was measured using an E-type viscometer ("TVE-25L", manufactured by Toki Sangyo Co., Ltd., 25°C).

[0058] (Weight average molecular weight) 2 g of the synthesized phenolic resin (aqueous solution with a solid content of 50% by mass) was diluted with 2 g of pure water and 10 g of tetrahydrofuran (THF), and the pH was adjusted to 4.0 with a 1 mol / L aqueous hydrochloric acid solution. The solution was separated into two layers, and the organic phase (upper layer) was separated and diluted 5 times with THF to prepare a sample. Measurement was carried out by gel permeation chromatography (GPC) under the following measurement conditions. <Measurement conditions> Equipment used: "HLC-8320GPC", manufactured by Tosoh Corporation Columns used: The following two columns are connected in series "TSKgel (registered trademark) G3000HXL," manufactured by Tosoh Corporation, 1 bottle "TSKgel (registered trademark) G2000HXL," manufactured by Tosoh Corporation, 2 bottles Column temperature: 40℃ Detector: Refractive index (RI) detector Eluent: tetrahydrofuran ·Flow rate: 0.8mL / min Sample injection volume: 50 μL Standard sample: Polystyrene

[0059] (ortho orientation) The synthesized phenolic resin 13 The o / p ratio was determined by C-NMR and FT-IR. -1(ortho position) and 820cm -1 The peak area ratio (para position) was defined as the o / p ratio.

[0060] (Synthesis Example 1) A reactor equipped with a condenser, thermometer, and stirrer was charged with 500.0 parts by weight of phenol, 1099.9 parts by weight of a 50% by weight aqueous formaldehyde solution (molar ratio of formaldehyde to phenol [F / P] = 3.45), and 90.0 parts by weight of barium hydroxide. The mixture was reacted at 60°C for 5.5 hours and then cooled to below 40°C. 80 parts by weight of 30% by weight sulfuric acid was added to the reaction product to neutralize it to pH 7.3, and then 17.1 parts by weight of water was added to obtain a high-ortho resol phenolic resin (aqueous solution with a 50% solids content: wood treatment agent 1; pH 7.3). The water dilutability of wood treatment agent 1 was over 4000%, the viscosity was 18 mPa·s, and the weight-average molecular weight of the high-ortho resol phenolic resin was 380. 13 The o / p ratio measured by C-NMR was 2.88, and the o / p ratio measured by FT-IR was 3.56.

[0061] (Synthesis Example 2) A reactor equipped with a condenser, thermometer, and stirrer was charged with 500.0 parts by mass of phenol, 574.5 parts by mass of a 50% by mass aqueous formaldehyde solution (molar ratio of formaldehyde to phenol [F / P] = 1.8), and 44.8 parts by mass of a 48% by mass aqueous sodium hydroxide solution. The mixture was reacted at 65°C for 4 hours and then cooled to below 50°C. 29.6 parts by mass of boric acid and 181.8 parts by mass of water were added to the reaction product to obtain a random-type resol phenolic resin (aqueous solution with a 50% by mass solids content: wood treatment agent 2; pH 7.5). The water dilutability of wood treatment agent 2 was over 4000%, the viscosity was 40 mPa·s, and the weight-average molecular weight of the random resol phenolic resin was 300. 13 The o / p ratio measured by C-NMR was 1.49, and the o / p ratio measured by FT-IR was 1.79.

[0062] [Preparation of wood samples] Example 1 A solid cedar board (length: approximately 12 cm, width: approximately 12 cm, thickness: approximately 3 cm; the same applies below) was impregnated with wood treatment agent 1 at room temperature (25°C) under reduced pressure of 933 hPa for 1 hour, then the temperature was raised from 40°C to 100°C and heat-treated for 72 hours, followed by drying. The temperature was then raised from 100°C to 150°C and heat-treated for 5 hours to produce treated wood sample 1. Treated wood sample 1 had a mass increase of 12.6% compared to the solid cedar board.

[0063] Example 2 Wood treatment agent 1 was applied to a solid cedar board with a brush, and then heat-treated in the same manner as in Example 1 to produce treated wood sample 2. Treated wood sample 2 had a mass increase of 2.9% compared to the solid cedar board.

[0064] (Comparative Example 1) The untreated sample was a solid cedar board.

[0065] (Comparative Example 2) Solid cedar boards were heat treated in the same manner as in Example 1 to prepare heat-treated samples.

[0066] (Comparative Example 3) Treated wood sample 2 was prepared by the same impregnation and heat treatment as in Example 1, except that wood treating agent 2 was used instead of wood treating agent 1 in Example 1.

[0067] [Outdoor exposure test] Each wood sample of the examples and comparative examples was subjected to an outdoor exposure test to evaluate weather resistance.

[0068] (Test 1) The wood sample was placed outdoors in a sunny location with the board surface (12 cm long and 12 cm wide; the same applies below) facing south and the lower half of the board surface (6 cm long) buried in the soil to fix the wood sample. Three, nine, and thirteen months after the start of the test, the soil on the surface of the wood sample was removed, and the lightness and chromaticity (L * a * b *The color difference ΔL of the exposed part above ground was measured using a color difference meter (CR-10, manufactured by Konica Minolta Japan Inc.; the same applies hereinafter) and the color of the buried part was used as the standard. * , Δa * and Δb * asked for. The length, width and thickness of the wood sample were measured with a vernier caliper, and the rate of change was calculated based on the dimensions immediately before the start of the test.

[0069] Table 1 shows the results of the change over time in color difference for the wood samples of Example 1 and Comparative Examples 1 to 3. * As the value increases in the positive (+) direction, the color becomes brighter (whiter), and as the value increases in the negative (-) direction, the color becomes darker (blacker). * As the value increases in the positive (+) direction, the red color becomes stronger, and as the value increases in the negative (-) direction, the green color becomes stronger. * indicates that increasing the value in the positive (+) direction makes the color yellower, and increasing the value in the negative (-) direction makes the color bluer.

[0070] [Table 1]

[0071] Table 2 shows the results of the dimensional change rates for the wood samples of Example 1 and Comparative Examples 1 and 2.

[0072] [Table 2]

[0073] (Test 2) In a sunny outdoor location, the wood sample was fixed horizontally at a height of 1 m from the ground with the board surface facing upward. Just before the start of the test, and one and three months after the start of the test, the lightness and chromaticity of the color of the plate surface facing up were measured with a colorimeter, and the color difference ΔL was measured using the color just before the start of the test as the standard. * , Δa * and Δb * asked for.

[0074] Table 3 shows the change in color difference over time for the wood samples of Example 2 and Comparative Example 1.

[0075] [Table 3]

[0076] As can be seen from the results shown in Tables 1 and 3, the wood samples impregnated or coated with the wood treatment agent of this embodiment (Examples 1 and 2) showed reduced loss in brightness over time and reduced intensification of the blue color. This indicates that the wood treatment agent of this embodiment prevents darkening of treated wood due to the oxidation reaction of the phenolic resin in outdoor environments exposed to sunlight, wind, and rain, thereby providing good weather resistance. Furthermore, as can be seen from the results shown in Table 2, it was confirmed that the wood sample impregnated with the wood treatment agent of this embodiment (Example 1) showed reduced dimensional change over time. This indicates that the wood treatment agent of this embodiment can maintain good dimensional stability in outdoor environments exposed to sunlight, wind, and rain.

Claims

1. A wood treatment agent containing a high-ortho resole phenolic resin.

2. 2. The wood treatment agent of claim 1, wherein the high-ortho resole phenolic resin is water-soluble.

3. 2. The wood treating agent according to claim 1, wherein the high-ortho resol phenolic resin has a weight average molecular weight of 100 to 8,000.

4. 2. The wood treating agent according to claim 1, which has a viscosity at 25°C of 1 to 3,000 mPa·s.

5. 2. The wood treating agent according to claim 1, which has a pH of 5.0 to 10.

0.

6. The wood treatment agent according to claim 1, which is a coating agent or an impregnation agent.

7. Treated wood having a high-ortho resole phenolic resin in at least a portion of the interior or surface of the wood.

8. Treated wood that has been treated with the wood treating agent according to any one of claims 1 to 6 and has a high-ortho resol phenolic resin in at least a portion of the interior or surface of the wood.

9. A method for producing treated wood, comprising impregnating or coating wood with the wood treating agent according to any one of claims 1 to 6, and then heat treating the wood.

Images