JP2011068108A - Wood modifying agent and modified wood - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wood modifying agent and a wood modifying method, by which superior dimensional stability and durability can be imparted to wood and by which, by the use of natural resin, adverse effect on an environment and health can be prevented or mitigated when manufacturing the wood modifying agent, processing wood, and using modified wood. <P>SOLUTION: The wood modifying agent contains vegetable oil containing epoxy group and a hardening agent. The wood modifying method is characterized in that, after wood is treated with the wood modifying agent, the wood is heated and hardened. The modified wood is obtained by modifying wood through the use of the wood modifying agent or the wood modifying method. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a wood modifier, a modified wood, and a method for modifying a wood.

When wood is used outdoors, the amount of water contained in the wood increases due to the influence of rainwater, moisture, etc., and as a result, it is likely to decay or to undergo dimensional changes and cracks by repeated expansion and contraction. In addition, when used indoors in an environment with a lot of moisture and moisture, such as around water, various problems such as dimensional changes, cracks, and mold contamination are likely to occur.
On the other hand, in the exterior of a house, there is a request to use wood for decks, porch pillars, pergola, sashes, etc., and in the interior of a house, there is a request to use wood around the vanity and bath etc. There is. However, if the wood is used as it is in such a place, various problems as described above occur.

Therefore, in order to solve these problems, attempts have been made to improve various performances such as dimensional stability and durability of wood by injecting synthetic resin (monomers and low molecular weight materials) into wood and curing it. Has been made.
However, many of the attempts up to now have used petroleum synthetic resins as the main component, and most of those currently in practical use are formaldehyde resins. Therefore, it cannot be said that it is preferable from the viewpoints of sustainability of petroleum as a raw material and environmental, safety and health in all cycles from production to use of products.

  For example, Patent Document 1 discloses a wood treatment method using urea / formaldehyde resin, Patent Document 2 discloses a wood treatment method using phenol / formaldehyde resin, and Patent Document 3 discloses a cyclic ester compound and a formaldehyde resin. A wood processing method using melamine and Patent Document 4 disclose a wood processing method using a melamine-formaldehyde resin. All of them use petroleum-based synthetic resin as a main component, and also use a large amount of formaldehyde that is harmful to the human body and the environment as a curing agent.

  Patent Document 5 discloses a wood treatment method using an acrylic compound and a cyclic ester compound, and Patent Document 6 discloses a wood treatment method using a water-soluble epoxy compound. These are also petroleum-based synthetic resins.

In consideration of sustainability and the influence on the environment and the human body, it is preferable to use a natural resin as a main component. As a method using an aqueous natural resin, a wood treatment method using a polycarboxylic acid derived from citric acid or the like has been disclosed (see Patent Document 7, etc.), but in such a method, dimensional stability of the wood is disclosed. ASE, which is an index of anti-swelling ability, which is an index indicating the above, was not necessarily sufficient.
In addition, as a technique using an oily natural resin, a method of modifying wood with vegetable oils and fats as a main component is disclosed (see Patent Documents 8 and 9). However, these conventional methods do not sufficiently advance resination of vegetable oils and fats, resulting in insufficient performance improvement due to insufficient resination and unpleasant oily odor when heating and cutting the modified wood after treatment. There is a problem that oils and fats are likely to elute due to aging.

  Although it is not a technique related to wood processing, a technique using an epoxidized vegetable oil or fat is known as a technique for producing a resin molded body mainly composed of a natural vegetable oil or fat (see Patent Documents 10 and 11, etc.). However, these techniques are essentially different from wood modification methods because of the high curing temperature of the resin or the purpose of producing a single molded product.

JP-A-5-154808 Japanese Patent Laid-Open No. 10-52804 JP-A-6-238613 JP-A-6-73333 JP-A-8-80508 Japanese Patent Laid-Open No. 10-166316 JP 2008-265201 A JP-A-8-118318 JP-A-8-118319 Japanese Patent Laid-Open No. 2006-241331 Japanese Patent Laid-Open No. 2004-256596

Accordingly, the object of the present invention is to provide excellent dimensional stability and durability to wood, and by using a naturally-derived resin, it can be modified at the time of manufacturing a wood modifier or at the time of processing wood. An object of the present invention is to provide a wood modifier and a method for modifying wood that can prevent or reduce adverse effects on the environment and health when using wood.
Another object of the present invention is to provide a modified wood that is excellent in dimensional stability and durability, and that is unlikely to adversely affect the environment and health during its production and use.
Examples of prevention or reduction of adverse environmental impact include reduction of oil consumption, reduction of carbon dioxide generation, and / or reduction of load on the environment after disposal. ,

As a result of intensive studies to solve the above problems, the present inventors have obtained a resin composition in which a vegetable oil or fat having an epoxy group, preferably an epoxidized fatty acid triglyceride, and a curing agent (a catalyst if necessary) are mixed. It has been found that by treating wood, excellent dimensional stability and durability can be efficiently imparted to the wood.
The present invention has been completed based on the above findings and further studies.
That is, this invention achieves said objective by providing the wood modifier characterized by containing the vegetable oil and fat containing an epoxy group, and the hardening | curing agent which reacts with an epoxy group.
The present invention also provides a method for modifying a wood, wherein the wood modifier is applied or impregnated on wood and then heated and cured.
Moreover, the modified wood obtained by processing with the said wood modifier is provided.

According to the wood modifier and the modification method of the present invention, it is possible to impart excellent dimensional stability and durability to wood, and by using a naturally-derived resin, It is also possible to prevent or reduce adverse effects on the environment and health during the treatment of wood and the use of modified wood.
The modified wood of the present invention is excellent in dimensional stability and durability, and is less likely to adversely affect the environment and health during its production and use.

FIG. 1 is a graph showing changes in water absorption. FIG. 2 is a graph showing a change in water absorption capacity (WR: Water Repellency) when Comparative Example 1 is used as a reference. FIG. 3 is a graph showing a change in expansion coefficient. FIG. 4 is a graph showing a change in anti-swelling ability (ASE) when Comparative Example 1 is used as a reference.

Hereinafter, the present invention will be described in detail based on preferred embodiments thereof.
The wood modifier of one embodiment of the present invention contains a vegetable oil containing an epoxy group and a curing agent that reacts with the epoxy group. The woody modifier of another embodiment of the present invention has a first agent containing a vegetable oil containing an epoxy group and a second agent containing a curing agent, and the first agent and the second agent in use. Are mixed and used.

(vegetable oil)
As the “vegetable fats and oils containing epoxy group” used in the present invention, any of epoxidized vegetable fats and oils obtained by epoxidizing vegetable fats and oils and seeds of vegetable oils and fats originally containing epoxy groups can be used. .
As an example of the former, epoxidized linseed oil, safflower oil, soybean oil, tung oil, cocoon oil, castor oil, walnut oil, sunflower oil, sesame oil, rapeseed oil, squid oil, cottonseed oil, etc. are preferably used Can do. These epoxidized vegetable oils and fats may be used individually by 1 type, and may be used in combination of 2 or more type.
As a method for epoxidizing vegetable oils and fats, known methods can be used without particular limitation, and are described in, for example, US Pat. No. 4,647,678 and US Pat. No. 6,121,398. These methods can be used.

Examples of the latter (originally containing an epoxy group) include Prince L. et al. H. , Journal of Coating technology, Vol. 49, no. 12, pp. 88-93, can be preferably used Vernonia anthelmintica, Vernonia pauciflora, Euphorbia lagascae, Stokesia laevis, Cephalocroton pueschellii, Erlangea tomentosa, Aichornea cordifolia, fats and oils are oil extraction from plants such as Schlectendalia luzulaefolia as described in 1977 . Moreover, even if it is not specifically illustrated by the said literature thru | or this specification, all can be used if it is a vegetable oil and fat containing an epoxy group.
Vegetable oils and fats originally containing an epoxy group may be used alone or in combination of two or more. Moreover, you may use combining 1 or more types of the epoxidized vegetable oil and fat, and 1 or more types of the vegetable oil and fat of the kind originally containing an epoxy group.

  Among the vegetable oils and fats containing the epoxy group described above, it is preferable to use epoxidized soybean oil or epoxidized linseed oil from the viewpoints of performance, price, supply stability, and handling. These are stably supplied as stabilizers for vinyl chloride resin.

(Curing agent)
As the “curing agent” used in the present invention, a curing agent conventionally used for curing an epoxy resin can be used without particular limitation.
Examples of the curing agent used in the present invention include, for example, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyl nadic anhydride, hydrogen Methyl nadic anhydride, trialkyltetrahydrophthalic anhydride, methylcyclohexacene tetracarboxylic dianhydride, phthalic anhydride, trimetic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic dianhydride, ethylene glycol bisanhydro Examples thereof include trimetrate, glycerin bis (anhydrotrimetate) monoacetate, dodecenyl succinic anhydride, aliphatic dibasic acid polyanhydride, and chlorendic anhydride.

  Examples of amine compounds include aliphatic polyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, m-xylenediamine, trimethylhexamethylenediamine, 2-methylpentamethylenediamine, diethylaminopropylamine, and isophoronediamine. 1,3-bisaminomethylcyclohexane, bis (4-aminocyclohexyl) methane, norbornenediamine, 1,2-diaminocyclohexane, lalomine and other alicyclic polyamines, diaminophenylmethane, metaphenylenediamine, diaminodiphenylsulfone, etc. Aromatic polyamines, polyoxypropylenediamine, polyoxypropylenetriamine, polycyclohexylpolymian mixture, N-aminoethylpiperazine, etc. Other amines and modified amines, mention may be made of monoamines.

Examples of the imidazole compound include 2-ethyl-4-methylimidazole, 2-phenylimidazole, 1- (2-cyanoethyl) -2-ethyl-4-methylimidazole, 2,4-diamino-6- [ Examples include 2-methylimidazolyl- (1)] ethyl-s-triazine, 2-phenylimidazoline, 2,3-dihydro-1H-pyrrolo [1,2-a] benzimidazole.
Other curing agents include polyvalent carboxylic acids, formaldehyde condensates, halogenated acids, hydrazide derivatives, dicindiamides, boron halide complexes, organometallic complexes, onium salts, polythiols, phenols, isocyanates, Examples include ketimines, silanol group-containing polymers, other marine group-containing compounds, amine adduct type existing curing agents, organic oxides, and the like.
The above-mentioned curing agents may be used alone or in combination of two or more.

Among the curing agents described above, acid anhydride compounds, amine compounds and the like that react with an epoxy group to form a resin skeleton are preferred.
The curing agent is preferably a liquid at room temperature (for example, 10 to 30 ° C.) from the viewpoint of impregnation with wood, etc., and an acid that is liquid at room temperature from the viewpoint of safety, handleability, performance, and price advantage. An anhydride is more preferable, and methyltetrahydrophthalic anhydride is particularly preferable. Examples of methyltetrahydrophthalic anhydride include “MT-500” from Shin Nippon Rika Co., Ltd., “QH-200” from Nippon Zeon Co., Ltd., “HN-2200” from Hitachi Chemical Co., Ltd., Dainippon Ink and Chemicals, Inc. It is also preferable to use “B-570” manufactured by Kogyo Co., Ltd.

(catalyst)
The wood modifier of the present invention may contain a catalyst in addition to the vegetable oil and the curing agent for the purpose of reducing the reaction temperature and shortening the reaction time. As a catalyst, the catalyst currently used as a catalyst of an epoxy resin hardening | curing agent can be especially used without a restriction | limiting.
When an example of a preferable catalyst is given, when an acid anhydride compound is used as a curing agent, it is preferable to use a tertiary amine compound or an imidazole compound as the catalyst. Moreover, when using an amine compound as a hardening | curing agent, it is preferable to use acids, phenols, and alcohols as a catalyst. As the curing agent and the catalyst, it is preferable to use an acid anhydride as the curing agent and imidazoles that are liquid at room temperature as the catalyst from the viewpoints of safety, handleability, and performance.

(Mixing ratio, etc.)
The composition of each component in the wood modifier can be appropriately determined depending on the desired performance, and the desired performance itself varies depending on the application and cannot be defined unconditionally.
The number of epoxy groups contained in the epoxidized vegetable oil varies depending on the number of unsaturated bonds and the degree of epoxidation of each vegetable oil. Theoretically, how much curing agent is reacted per unit epoxy group depends on 1.0 epoxy group with respect to epoxy group 1.0 and active hydrogen group with amine curing agent, or acid anhydride with acid anhydride curing agent. Groups 0.8 to 1.0 are preferred. However, this depends on the type of curing agent and the desired degree of crosslinking density of the cured product.
If an example is given, the compounding quantity of the hardening | curing agent with respect to 100 mass parts of epoxidized vegetable oils and fats will be 5-90 mass parts, and the compounding quantity of the catalyst with respect to 100 mass parts of epoxidized vegetable oils and fats will be 0.01-5 mass parts.

When an amine compound is used as the curing agent, the (active hydrogen equivalent / epoxy group) ratio is preferably 0.2 to 1.4, more preferably 0.4 to 1.0.
When an acid anhydride compound is used as a curing agent, the (acid anhydride group / epoxy group) ratio is preferably 0.2 to 1.4, more preferably 0.4 to 1.0.
If the (acid anhydride group / epoxy group) ratio is smaller than this, sufficient physical properties may not be obtained. Conversely, if the (acid anhydride group / epoxy group) ratio is larger than this, the reaction may be involved. It is not preferable because various side reactions caused by the free acid anhydride that has not been present increase the possibility of affecting the physical properties.
As a preferred specific example, when epoxidized soybean oil (epoxy equivalent: about 235) is reacted with methyltetrahydrophthalic anhydride (anhydride group equivalent: 166), which is an acid anhydride hardener, acid anhydride. Weight ratio of epoxidized soybean oil and methyltetrahydrophthalic anhydride when the ratio of the group to the epoxy group is 0.2 to 1.4 is the same as that when the ratio is 100: 14 to 99, 0.4 to 1.0 The weight ratio is 100: 28-70.
Conventionally, the addition amount g of a necessary curing agent per 100 g of epoxy resin is expressed as per hundred resin (= phr). This notation is simple and easy to understand in practice, but if the epoxy group equivalent or the acid anhydride group equivalent changes, the ratio of the acid anhydride group to the epoxy group changes greatly. In the above example, it can be expressed as 14 to 99 phr and 28 to 70 phr.

(Diluent)
Various diluents can be added for the purpose of lowering the viscosity of the wood modifier and improving the infiltration into wood and the foamability during handling. Such a diluent that is involved in the reaction with the epoxy group is called a reactive diluent, and one that is not involved in the reaction is called a non-reactive diluent.
Examples of diluents that can be used as reactive diluents include monofunctional alcohols such as n-butanol glycidyl ether and higher alcohol glycidyl ether, monofunctional phenols such as butylphenyl glycidyl ether and cresyl glycidyl ether. As monofunctional carboxylic acids such as brominated cresyl ether, synthetic fatty acid glycidyl ester, glycidyl methacrylate, etc. As monofunctional others, styrene oxide, etc. As polyfunctional dihydric alcohols 1,4 As polyfunctional trihydric alcohols such as butanediol diglycidyl ether and 1,6-hexanediol diglycidyl ether, as polyfunctional polyglycols such as trimethylolpropane triglycidyl ether and glycerin triglycidyl ether , Polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, etc., polyfunctional dibasic acid type, dimer acid diglycidyl ester, etc., polyfunctional amine type, diglycidyl aniline, diglycidyl toluidine etc. Other examples include alkylene carbonate.
These may be used individually by 1 type and may be used in combination of 2 or more type.

Examples of diluents that can be used as non-reactive diluents include natural oils such as vegetable oils, petroleum and coal oils, tar, coumarone / indene resin, creosote oil, etc., plasticizers such as dibutyl phthalate, Dioctyl phthalate, etc., liquid resin, xylene resin, toluene resin, etc. Others include aliphatic hydrocarbon organic solvent, aromatic hydrocarbon organic solvent, isoparaffin organic solvent, pine oil, nonylphenol, alcohol, etc. Can do.
These may be used individually by 1 type and may be used in combination of 2 or more type.
Among these, coumarone-indene resin is preferred when it is used under severe conditions, such as when it is installed outdoors, and there is a high possibility that biological degradation will occur.

(Other additives)
In the wood modifier of the present invention, preservatives, insecticides, fungicides, water repellents, ultraviolet absorbers, flame retardants, fillers, coupling agents, elastomers, as long as the effects of the present invention are not impaired. Various additives such as pigments / dyes and plasticizers can be added. These may be used individually by 1 type and may be used in combination of 2 or more type.

(Formulation method etc.)
The wood modifier of one embodiment of the present invention is obtained by mixing the vegetable oil and fat, the curing agent, and other components (catalyst, additive, etc.) blended as desired at the same time or in an appropriate order. .
Moreover, the wood modifier of other embodiment of this invention is divided and stored in the 1st agent containing the said vegetable oil and fat, and the 2nd agent containing the said hardening | curing agent, and the 1st agent and 2nd in use. Used in combination with an agent. When the vegetable oil and the curing agent are left in a mixed state for a long time, the viscosity gradually increases, and the impregnation property and workability for wood, the physical properties of the cured product, and the like may deteriorate. By separating the first agent and the second agent and mixing them before use, it is possible to prevent such inconvenience and efficiently perform a wood modification process or the like. The time from mixing to applying or impregnating the wood can be adjusted as appropriate, such as several seconds, minutes, hours, a day, a week, half a month, and January.

  Moreover, the wood modifier which has the 1st agent containing the said vegetable oil and fat and the 2nd agent containing the said hardening | curing agent contains the 1st container which accommodated the 1st agent containing the said vegetable oil and fat, and the said hardening | curing agent. The second container containing the second container containing the first agent containing the first agent containing the vegetable oil and fat and the second agent containing the hardener. Use the wood modifier for a long period of time, such as selling composite containers with parts, etc., by distributing (selling etc.) the vegetable oil and the hardener without mixing them and mixing them before use It is preferable from the viewpoint of storage. In such a case, other components (catalyst, other additives, etc.) blended as desired may be contained in either the first agent or the second agent, and some of the components may be contained in the first agent. Other components may be contained separately in the second agent. Furthermore, a catalyst or other additive may be used as the third agent, and the first to third agents may be mixed and used in use.

(Processing method)
The wood modification method of the present invention includes a step of treating wood with a wood modifier and a step of curing the wood modifier. The wood modifier distributed (sold, etc.) in a state where the vegetable oil and the curing agent are not mixed is used for the treatment with the vegetable oil and the curing agent in a mixed state.
The treatment in the step of treating with the wood modifier is a treatment in which the wood modifier is brought into contact with the surface and / or inside of the wood, and examples thereof include a coating treatment, a dipping treatment, and a forced impregnation treatment.

The coating process is a process of coating the wood modifier on the surface of the wood to be treated. As the coating method, various known methods such as waste, brush, spray, roll coater and the like can be employed without particular limitation.
The dipping treatment is a treatment in which the wood to be treated is dipped in a wood modifying agent. For example, the wood is dipped in a wood modifying agent placed in a container.
The forced impregnation treatment is a treatment for forcibly impregnating (injecting) the wood modifier into the treated wood. As the forced impregnation treatment, various known methods such as a pressure reduction method, a pressure method, a pressure reduction method, a hot bath method, a hot and cold repeated method, a submerged roll press method, and the like can be employed without particular limitation.
The various types of processing described above may be performed repeatedly with the same type of processing, or may be sequentially performed by combining two or more types of different processing.
Moreover, it is preferable to perform these processes, for example at 10-80 degreeC, especially room temperature (for example, 15-30 degreeC).

The amount of treatment with the wood modifier necessary for modifying the wood varies depending on the desired degree of modification and cannot be defined unconditionally. This is because, for example, when used on an indoor flooring or the like, a treatment only near the surface is sufficient, and when used outdoors, a considerable degree of infiltration into the wood is required.
The step of curing the wood modifier is preferably performed by heating vegetable oil and fat, a curing agent, and the like that are in contact with or impregnated with wood in a mixed state. As the heat curing method, various known heat curing methods can be used without particular limitation. The heating temperature is preferably 60 to 180 ° C, more preferably 100 to 140 ° C, and still more preferably 110 to 120 ° C. The heating time can be appropriately determined according to the heating temperature, the progress of curing, and the like. As an example, in the case of heating and curing at 120 ° C., the curing reaction can be terminated with 1 to 4 hours as a guide.

Wood after heat treatment is modified in terms of dimensional stability, durability against decay and insect erosion, or other properties due to the presence of cured resin on the surface and / or inside.
The wood to be modified in the present invention (treated wood) may be solid wood obtained by sawing softwood or hardwood, laminated wood, or various woody materials. Examples of the wood material include plywood, single plate laminate (LVL), particle board, MDF, and the like.
Modified wood can be used for various purposes, such as decks, porch pillars, pergola, sashes, and even indoors where moisture is applied or used as wood around bathroom vanities, bath tubs, walls, etc. Can do.

  As mentioned above, although preferred embodiment of this invention was described, each invention is not restrict | limited to said embodiment, It can change suitably.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. However, the present invention is not limited to the examples.

(Preparation of wood modifier)
Epoxidized soybean oil (ADEKA Co., Ltd .: Adekasizer) as the main agent, methyltetrahydrophthalic anhydride (Hitachi Chemical Industry Co., Ltd .: HN-2200) as the curing agent, 1,2-dimethylimidazole (Wako Pure Chemical ( Resin liquids (woody modifiers) of Examples 1 to 3 were obtained by changing the mixing ratio of the main agent and the curing agent. Table 1 shows the composition of the resin liquid.

(Wood modification)
About each of the resin liquid of Examples 1-3, the pressure reduction injection | pouring to a cedar sapwood (cross-section 20x20mm, length 50mm) was performed. The injection treatment was carried out for 60 minutes by reducing the pressure in the resin solution for 30 minutes and returning to normal pressure in the resin solution. Then, after pulling up from the resin liquid and wiping off the excess resin liquid with a waste cloth, it was placed on a wire mesh and decompressed for 60 minutes again to discharge the excess resin liquid in the wood. Then, it removed from the decompression tank, the excess resin liquid adhering to the sample surface was wiped off again with the waste, and was cured at room temperature overnight. The cured wood was heat-cured in an oven at 120 ° C. for 4 hours to obtain modified wood.

(test)
The modified wood modified with the resin liquids of Examples 1 to 3 was treated with the wood of Examples 1 to 3 and the untreated cedar sap material similar to that used in Examples 1 to 3 of Comparative Example 1. A treatment liquid in which cobalt naphthenate equivalent to 0.1% by weight in terms of metal was added to wood and boiled linseed oil as a dryer, and the same cedar sapwood was injected under reduced pressure and heat-cured in the same procedure as in the example. Was subjected to the following test as wood of Comparative Example 2.

1. Anti-water absorption test 1-1. Test method The wood of each of the examples and comparative examples was forcibly submerged in a plastic container filled with water at a depth of 5 cm so as not to float, and the water absorption over time was measured over 10 days. By comparing the anti-water absorption ability.
Furthermore, the water absorption capacity (WR: Water Repellency) (%) was calculated by the following formula.
WR (%) = {(W ₀ −W ₁ ) ÷ (W ₀ )} × 100
(W ₀ : water absorption amount of control (Comparative Example 1), W ₁ : water absorption amount of Examples 1 to 3 and Comparative Example 2)

1-2. Results of Anti-Water Absorption Test FIG. 1 shows changes in water absorption, and FIG. 2 shows changes in anti-water absorption (WR: Water Repellency) when Comparative Example 1 is used as a reference.

  As can be seen from the results shown in FIG. 1, Examples 1 to 3 are superior to Comparative Examples 1 and 2 in anti-water absorption ability. Since wood decays when the moisture content continues to be higher than 28-30%, its excellent water absorption capacity helps greatly reduce the risk of decay. That is, the reforming treatment according to the present invention significantly contributes to improving the durability in outdoor or indoor water environment.

2. Dimensional stability (anti-swelling ability) test 2-1. Test method The wood of each of the examples and comparative examples was forcibly submerged so as not to float in a plastic container containing water, followed by sufficient water absorption at a reduced pressure of 30 minutes and then at a normal pressure of 60 minutes. The cross-sectional dimensions were measured. After the measurement, it was dried for 12 hours or more with a dryer at 105 ° C. Dimensional stability was evaluated by repeating this for 10 cycles.
Further, anti-swelling ability (ASE) (%) was calculated by the following formula.
ASE (%) = {(S ₀ −S ₁ ) ÷ (S ₀ )} × 100
(However, S ₀ : Cross-sectional dimension of control (Comparative Example 1), S ₁ : Cross-sectional dimensions of Examples 1 to 3 and Comparative Example 2)

2-2. Results of dimensional stability (anti-swelling ability) test FIG. 3 shows the change in expansion coefficient, and FIG. 4 shows the change in anti-swelling efficiency (ASE) when Comparative Example 1 is used as a reference. .

  As can be seen from the results shown in FIG. 3, Examples 1 to 3 are all superior to Comparative Example 1 in anti-swelling ability. Moreover, although the comparative example 2 also showed high anti-swelling ability, as above-mentioned, it is inferior to anti-water absorption ability (refer FIG. 2). The modification treatment according to the present invention is excellent in anti-swelling ability and significantly contributes to the dimensional stability of wood.

3. 3. Crack resistance test 3-1. Test method The wood of each of the examples and comparative examples was forcibly submerged so as not to float in a plastic container containing water, followed by sufficient water absorption at a reduced pressure of 30 minutes and then at a normal pressure of 60 minutes. The cross-sectional dimensions were measured. After the measurement, it was dried for 12 hours or more with a dryer at 105 ° C. This was regarded as one cycle, repeated 10 cycles, and the occurrence rate of cracks in the wood after 10 cycles was evaluated.

The degree of cracking at the neck was evaluated according to the following evaluation criteria.
None: No cracking Minor: Slight cracking is observed Prominent: Clear cracking is observed

The rate of crack occurrence (%) was calculated by the following formula.
Kicks cracking incidence (%) = (Nf ÷ N) × 100
(However, Nf: number of specimens cracked at the neck, N: number of specimens subjected to the test)

3-2. Results of crack resistance test Table 2 shows the degree of cracking and the rate of occurrence after 10 cycles.

  As can be seen from the results shown in Table 2, all of Examples 1 to 3 have little or no occurrence of cracks at the end. On the other hand, the comparative example 1 and 2 have the remarkable piercing crack. It was confirmed that the modified wood subjected to the modification treatment according to the present invention is very excellent in crack resistance even under severe conditions in which forced wetting and drying are repeated. That is, according to the present invention, it is possible to impart excellent dimensional stability and durability to wood while using as a main component a natural vegetable oil that is gentle to the environment and the human body.

Claims (7)

  A wood modifier comprising a vegetable oil containing an epoxy group and a curing agent.   The wood modifier which has the 1st agent containing the vegetable oil and fat containing an epoxy group, and the 2nd agent containing a hardening | curing agent, and mixes and uses the 1st agent and the 2nd agent in use.   The wood modifier according to claim 1 or 2, wherein the vegetable oil is epoxidized soybean oil.   The wood modifier according to any one of claims 1 to 3, wherein the curing agent is an acid anhydride compound.   The wood modifier according to any one of claims 1 to 4, further comprising an imidazole compound in addition to the vegetable oil and the curing agent.   A method for modifying wood, comprising: treating wood with the wood modifier according to any one of claims 1 to 4, followed by heating and curing.   Modified wood obtained by modifying with the wood modifier according to any one of claims 1 to 4.

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