JP6348393B2 - Method for producing modified wood - Google Patents

Description

  The present invention relates to a method for producing modified wood used for flooring materials, exterior materials, interior materials and the like.

  Modified wood in which chemical properties and physical properties have been modified by infiltrating wood with chemicals and resins is widely used for flooring and the like. And in the case of manufacture of this modified wood, the process for improving the permeability | transmittance of a chemical | medical agent etc. is given.

  As such processing methods, for example, compression methods that improve the permeability of drugs and the like by compressing wood in the air or liquid are known (for example, Patent Documents 1 and 2, Non-Patent Documents 1 and 2). Patent Document 3 discloses a technique in which wood is liquid-proof coated, immersed in a liquid pressurizing medium and pressed to cause many fine cracks in the wood structure, and then the modified treatment liquid is infiltrated. Has been. Patent Document 4 discloses that the technique disclosed in Patent Document 3 imparts brittleness by infiltrating and curing wood with a curable resin before liquid-proof coating of wood.

  Also known is an insizing method for piercing the surface of wood. Furthermore, as a substitute for the insizing method, it has been studied to locally compress wood (see Non-Patent Document 3).

JP 2008-307798 A JP 2010-221645 A Japanese Patent No. 3332277 Japanese Patent Laid-Open No. 9-29710

Nara Prefectural Forest Technology Center research report NO. 34 (2005) "Wood modification by chemical injection using compression method (2nd report)" Nara Prefectural Forest Technology Center research report NO. 26 (1996) "Liquid injection into poorly permeable wood (5th report)" Vol.20, No.3, 2006 “Impregnation of softwood in Hokkaido by injectability improvement treatment (1st report)-Injectability by partial compression of the surface layer of wood. J. Hokkaido For. Prod. Res. Improvement effect

  In the case of the compression method, although the effect of improving the permeability is recognized, if it is attempted to increase the effect, a treatment with a high compression ratio is required, which causes macroscopic destruction of the wood or the compression. Since wood is not permanently fixed, there arises a problem that there is a concern about the release of compressive strain in the environment of use, so the compression rate needs to be lowered, and as a result, a significant improvement in permeability cannot be obtained.

  In the case of the insizing method, the penetration of drugs etc. can only be expected up to the site where the stab was made and its periphery, and since many regular holes are arranged on the surface of the wood, the surface of the material inherent to the wood There is a problem that the appearance of the camera is significantly impaired.

  An object of the present invention is to greatly improve the permeability of chemicals and the like to wood without deteriorating the design feeling in the production of modified wood.

  The invention according to claim 1 includes a first step of forming fine recesses on the surface of the wood, a second step of water-spraying on the surface of the wood having fine recesses formed in the first step, and water in the second step. A third step of compressing the beaten wood with a roll press so that the amount of compression is greater than the depth of the fine recesses on the surface of the wood; a fourth step of drying the wood compressed in the third step; Is a method for producing a modified wood.

  According to the first aspect of the present invention, in the production of modified wood, water is applied to the surface of the wood on which the fine recesses are formed, and the surface is compressed by a roll press to spread the fine recesses and then dried. The penetrability of chemicals and the like into wood can be greatly improved without impairing the design feeling. This is because the fine recesses on the surface of the wood are compressed, the fine recesses are laterally spread, and stress is concentrated at the deepest part of the expanded micro recesses, resulting in fine cracks even deeper. In addition to being able to be made, water hammering before compression suppresses macroscopic destruction and consolidation of the surface and brings about a priming effect, resulting in an improvement in the permeability of drugs and the like. It is believed that there is.

  The invention according to claim 2 is the method for producing the modified wood according to claim 1, wherein the roll contacting the surface of the water-washed wood in the roll press used in the second step is a hard resin roll or a metal It is a roll.

  According to the invention which concerns on Claim 2, since the fine unevenness | corrugation of the surface of wood is compressed with a hard resin roll or a metal roll, the effect | action which spreads the fine recessed part of the surface of wood more effectively can be acquired. .

  According to the present invention, in the production of modified wood, water is applied to the surface of the wood having fine recesses formed on the surface, and the product is compressed by a roll press machine and then dried, so that the design feeling is not impaired. It is possible to greatly improve the permeability of such drugs.

(A)-(c) is explanatory drawing of the manufacturing method of the modified wood which concerns on embodiment. It is explanatory drawing of the permeability improvement effect of the chemical | medical agent etc. to wood. It is a graph which shows the osmosis | permeation distance of resin of Example 1 and Comparative Examples 1-1 to 1-4. It is a graph which shows the osmosis | permeation distance of resin of Example 2 and Comparative Example 2. In Examples 3-1 to 3-3 and Comparative Example 3, (a) is a graph showing the penetration distance of the resin, and (b) is a graph showing the amount of water absorption. It is a graph which shows the osmosis | permeation distance of resin of Example 4 and Comparative Examples 4-1 to 4-3.

  Hereinafter, embodiments will be described in detail.

  The modified wood manufacturing method according to the embodiment includes a first step of forming fine fine recesses on the surface of the wood 10 as shown in FIG. 1 (a), and a first step as shown in FIG. 1 (b). As shown in FIG. 1 (c), the second step of water-spraying the liquid L on the surface of the wood 10 in which fine recesses are formed in one step, and the amount of compression of the wood 10 water-sputtered in the second step The third step of compressing through the roll press machine 20 so as to be larger than the depth of the fine recesses on the surface of the substrate, the fourth step of drying the wood 10 compressed in the third step, and drying in the fourth step And a fifth step of modifying the wood 10 by infiltrating a drug or resin.

  According to the modified wood manufacturing method according to the embodiment, the liquid L is dipped on the surface of the wood 10 on which fine fine recesses are formed, and the amount of compression is greater than the depth of the fine recesses on the surface of the wood 10. By compressing with the roll press machine 20 so that it may become large, and making it dry, the permeability | transmittance of the chemical | medical agent etc. to the timber 10 can be improved significantly, without impairing a design feeling. This is because, as shown in FIG. 2, the fine concave portion on the surface of the wood 10 is compressed, so that the fine concave portion is laterally expanded, and stress is concentrated on the deepest portion of the expanded fine concave portion, In addition to being able to generate fine cracks C to the deep part, by spraying the liquid L before compression, it suppresses macroscopic destruction and consolidation of the surface and brings about a priming effect, It is thought that the penetration of drugs and the like can be improved.

(First step)
In the first step, as shown in FIG. 1A, fine fine recesses are formed on the surface of the wood 10.

  The wood 10 to be processed is not particularly limited. For example, cedar, cypress, red pine, larch, mouse, zelkova, sen, pine, fir, oak, wig, chestnut, sina, tochi, enju, beech, hippo , Urushi, Tamo, Sawara, Kusu, Camellia, Kiri, Spruce, Bamboo, Yew, Kozo, Mulberry, Oak, Boxwood, Sakura, Hoo, Poplar, Eucalyptus, Asunaro, Ginkgo, Inuaki, Maple, Tsuga and the like. The wood 10 may be a plate material or a shaft material. The wood 10 may be either a solid material or a composite material such as plywood.

  The wood 10 to be processed is preferably cured before the forming process of the fine recesses. For example, the temperature condition is 20 to 30 ° C. and the humidity condition is 40 to 70%.

  Examples of the method for processing the fine recesses on the surface of the wood 10 include, for example, pressing using a mold material embossed to simulate a pipe, surface sanding with coarse sandpaper, shot blasting with fine beads colliding, and brush For example, polishing. Of these, from the viewpoint of versatility, surface sanding with sandpaper having a coarse particle size and shot blasting or brush polishing in which fine beads collide with each other are preferable.

  From the viewpoint that the fine recess processing method can obtain an excellent design, pressing using a mold material provided with an emboss simulating a pipe is preferable. In this case, the end of the road-shaped embossed pattern may have a curved cross-section, but by making the cross-section acute angle that causes buckling fracture on the surface of the wood 10 to be modified, The effect of improving the permeability of drugs and the like is easily obtained.

  The fine recess processing method may be an insizing process. In the manufacturing method of the modified wood according to the embodiment, even if a large number of regular fine recesses are arranged on the surface of the wood 10 by the insizing process, it is compressed by the roll press machine 20 in the third step. It is possible to reduce the loss of the appearance of the surface by making the fine recesses formed by

  In the case of shot blasting, it is desirable that the abrasive particles to be used are fine from the viewpoint of the design of the surface of the wood 10, but it is preferable that the abrasive particles are large from the viewpoint of improving the effect of penetration of the chemicals into the wood 10. From the viewpoint of these balances, the particle size of the abrasive particles is preferably 20 to 1000 μm, more preferably 100 to 500 μm. In addition, what is necessary is just to select what does not produce a discomfort in the design of the surface of the timber 10 after water hammering, a roll press, and drying as an abrasive particle.

  In the case of brush polishing or insizing, it is preferable that the formation of fine recesses on the surface of the wood 10 has a lot of fine scratches from the viewpoint of improving the effect of penetration of a drug or the like into the wood 10. Further, from the viewpoint of the design of the surface of the wood 10, many fine flaws are made along the fiber direction of the wood 10 by matching the rotation direction of the brush and the cutting direction of the insizing blade with the fiber direction of the wood 10. It is preferable to form as follows. In the case of brush polishing, the diameter of the brush wire is preferably 0.1 to 1 mm, more preferably 0.25 to 0.35 mm.

(Second step)
In the second step, as shown in FIG. 1 (b), the liquid L is dipped on the surface of the wood 10 on which the fine recesses are formed in the first step.

  Before compressing with the roll press machine 20 in the third step, the surface of the wood 10 having fine recesses is wetted with the liquid L, so that macroscopic destruction of the surface during compression is suppressed and the appearance is maintained. be able to. In addition, when the surface of the wood 10 is compressed and the surface is consolidated, the permeability of the drug and the like is reduced. However, the surface consolidation during compression can be suppressed by water hammering. Therefore, this water hammering is very important in improving the permeability of the wood 10 to the chemicals.

  Here, “water hammering” in the present application means that the liquid L adheres to substantially the entire surface of the wood 10 in which the fine recesses are formed, and the liquid L is typically water. However, it may be a weak alkaline aqueous solution, a surfactant aqueous solution, an organic solvent, or the like. In addition, the liquid L used for water hammer is appropriately selected to improve the permeability of the drug or the like to the wood 10, and what kind of liquid L is used is the drug, the chemical liquid used in the fifth step, Alternatively, the permeability may be appropriately selected depending on whether the resin or the like is hydrophilic or hydrophobic.

  The water hitting means is not particularly limited, and examples thereof include spraying, brushing, and sponge roll application. From the viewpoint of uniformly attaching the liquid L, spraying and sponge roll application are preferable.

The application amount of the liquid L by water hammering is preferably 10 g / scale ² or more, more preferably 15 g / scale ² or more, and preferably from the viewpoint of suppressing macroscopic surface destruction and consolidation during compression. Is 30 g / scale ² or less, more preferably 20 g / scale ² or less. The application amount of the liquid L varies depending on the type of the wood 10 and the water hammering means, and is not limited to this range, but may be an amount that allows the liquid L to uniformly adhere to the surface of the wood 10.

(Third step)
In the third step, as shown in FIG. 1 (c), the wood 10 that has been hammered in the second step is passed through a roll press machine 20 so that the amount of compression is greater than the depth of the fine recesses on the surface of the wood 10. Compress. In addition, this compression process is performed before the liquid L dipped in the second step is naturally dried.

  As shown in FIG. 1C, the roll press machine 20 may have a pair of rolls 21, and may sandwich and convey the wood 10 while compressing the wood 10 with the pair of rolls 21. It may have one roll and a stage, and may convey while compressing the surface of the timber 10 placed on the stage with the roll. The material of the roll 21 is not particularly limited, but at least the roll 21 that comes into contact with the surface of the water-washed wood 10 can more effectively push the fine recesses on the surface of the wood 10 sideways. A hard resin roll such as a metal roll or hard urethane is preferred. As the hard resin roll, one having a roll surface hardness higher than the surface hardness of the wood 10 is selected.

  The conveyance speed of the wood 10 through the roll press machine 20 is, for example, 0.4 to 40 m / min.

  The number of times the wood 10 is passed through the roll press machine 20 may be one time or two or more times.

  The compression rate of the wood 10 through the roll press machine 20 is larger than the depth of the fine recesses on the surface of the wood 10 from the viewpoint of improving the permeability of the chemicals and the like and suppressing the cracking of the wood 10. Thus, it is preferably 5% or more of the surface wood material to be compressed, more preferably 15% or more, and preferably 30% or less, more preferably 20% or less.

  The amount of compression of the wood 10 to be compressed in the third step is larger than the depth of the fine recesses on the surface of the wood 10 formed in the first step, but the greater the difference, the more the micro recesses on the surface of the wood 10 are compressed. It can be restored and its design can be restored.

(4th process)
In the fourth step, the wood 10 compressed in the third step is dried.

  After compression by the roll press machine 20 in the third step, the wood 10 is dried in the fourth step. By this drying, moisture remains in the cells of the wood 10, and in the subsequent fifth step, the drug, the chemical solution Or it prevents that the penetration | invasion of resin etc. is inhibited.

  This drying may be either natural drying or stored in a dryer. Preferably, a ventilation dryer is used. The drying condition is, for example, drying for about 10 to 30 minutes in a dryer at 60 to 80 ° C.

(5th process)
In the fifth step, a liquid chemical or resin is infiltrated into the wood 10 dried in the fourth step to be modified.

  Examples of the drug include antiseptics, insecticides, flame retardants and the like. Examples of the preservative include fluorides, arsenic compounds, chromium compounds, chlorophenols, nitrophenols, and the like. Examples of insect repellents include phenols, inorganic fluorides, alkylammonium compounds, copper / azole compounds, polydene salts, gulin salts, borax, triazoles, pyrethroids, and the like. Examples of the flame retardant include borate, phosphate, hydrogen phosphate, carbonate, sulfate, hydrogen sulfate, silicate, nitrate, and hydrochloride. These chemicals that permeate the wood 10 are used as a solution dissolved in water or an organic solvent, or as a dispersion liquid dispersed in water or the like. The chemical modification of the wood 10 is achieved by these chemicals.

  Examples of the resin include phenolic resins, epoxy resins, melamine resins, urea resins, amino resins, glyoxal resins, polyurethane resins, polyacrylurethane resins, and resorcinol resins. Examples thereof include a curable liquid acrylic resin. These resins allow physical modification of the wood 10.

  The modified wood produced as described above is used for floor materials, exterior materials, interior materials and the like.

[Test Evaluation 1]
(Pre-modification pretreatment)
The following specimens of solid cedar (core material part) before modification were prepared. Each configuration is also shown in Table 1.

<Example 1>
A solid cedar wood (heart part) having a thickness of 12 mm was cured under a temperature of 23 ° C. and a humidity of 50% until reaching a constant weight.

  First, the surface of the hardened solid cedar wood surface was ground with sandpaper having a particle size of # 30 to form minute fine recesses (first step).

Next, water was sprayed on the surface of the solid cedar material in which fine concave portions were formed, and water was applied so that the coating amount was 16 g / scale ² (second step).

  Subsequently, the solid-cedared cedar wood was passed once at a conveyance speed of 0.5 m / min between a pair of metal rolls of a roll press machine having a clearance of 10 mm so that the compression ratio was 16%. And compressed (third step). This amount of compression was sufficiently larger than the depth of the fine recesses on the surface of the cedar solid material formed in the first step.

  Then, the compressed solid cedar material was put into a dryer set at 80 ° C. and dried until the mass before watering was reached (fourth step).

  The obtained specimen of solid cedar before modification was designated as Example 1.

<Comparative Example 1-1>
A test piece of solid cedar wood (core material part) having a thickness of 12 mm, which was not subjected to the first to fourth steps, was defined as Comparative Example 1-1.

<Comparative Example 1-2>
The test piece of the solid cedar material (core material part) before the modification | reformation which performed only the compression of the 3rd process, without performing the 1st process, the 2nd process, and the 4th process was made into Comparative Example 1-2.

<Comparative Example 1-3>
A test piece of solid cedar wood (core material part) before modification in which only the formation of fine concave portions on the surface by grinding in the first process was performed without performing the second to fourth processes was referred to as Comparative Example 1-3.

<Comparative Example 1-4>
A test piece of solid cedar (heart part) before modification, which was subjected to water hammering, compression and drying in the second to fourth steps without performing the first step, was referred to as Comparative Example 1-4.

(Test evaluation method)
The test piece was evaluated for resin permeability.

  Specifically, after the test piece was cured for one day under the conditions of a temperature of 23 ° C. and a humidity of 50%, the surface on the front side of the tree was measured with a roll coating machine set to a clearance 0.6 mm smaller than the thickness of the test piece. A liquid ultraviolet curable acrylic resin was applied to the film. The acrylic resin application was repeated until the mass of the test piece ceased to change.

  Next, the test piece coated with the acrylic resin was passed through a UV irradiator to completely cure the acrylic resin.

  Then, the test piece after the acrylic resin was cured was cut, the cross section was dyed with a toluidine blue solution, and the wood part and the resin part were applied separately, and the penetration distance of the acrylic resin was measured as the resin penetration performance by microscopic observation. .

(Test evaluation results)
FIG. 3 shows the test results of the penetration distance of acrylic resin.

  According to FIG. 3, it can be seen that although the resin permeability is improved by forming fine concave portions on the surface by grinding, the resin permeability is further improved by combining water hammering and compression.

[Test evaluation 2]
(Pre-modification pretreatment)
The following specimens of solid cedar (sapwood part) before modification were prepared. Each configuration is also shown in Table 2.

<Example 2>
A solid cedar (sapwood part) having a thickness of 9 mm was cured under a temperature of 23 ° C. and a humidity of 50% until reaching a constant weight.

  First, the surface of the hardened solid cedar wood surface was ground by shot blasting to form minute fine recesses (first step).

Next, water was sprayed on the surface of the cedar solid material in which fine concave portions were formed, and water was applied so that the coating amount was 26 g / scale ² (second step).

  Subsequently, the solid-cedared cedar wood was passed once at a conveyance speed of 0.5 m / min between a pair of metal rolls of a roll press machine in which a clearance of 7.6 mm was set so that the compression rate was 16%. And compressed (third step). This amount of compression was sufficiently larger than the depth of the fine recesses on the surface of the cedar solid material formed in the first step.

  Then, the compressed solid cedar material was put into a dryer set at 80 ° C. and dried until the mass before watering was reached (fourth step).

  The obtained specimen of the solid cedar before modification was designated as Example 2.

<Comparative example 2>
Without performing the third step, a test piece of solid cedar (sapwood portion) before modification, which was subjected to the formation of fine concave portions on the surface by grinding in the first, second and fourth steps, water hammering, and drying. It was set as Comparative Example 2.

(Test evaluation method)
The resin permeability of the test piece was tested and evaluated in the same manner as in Test Evaluation 1.

(Test evaluation results)
FIG. 4 shows the test results of the penetration distance of acrylic resin.

  According to FIG. 4, it can be seen that the effect of improving the resin permeability can be obtained by forming fine concave portions on the surface by shot blasting as in the case of grinding by sandpaper.

[Test Evaluation 3]
The following specimens of solid cedar (core material part) before modification were prepared. Each configuration is also shown in Table 3.

<Example 3-1>
A solid cedar wood (heart part) having a thickness of 9 mm was cured under conditions of a temperature of 23 ° C. and a humidity of 50% until reaching a constant weight.

  First, the surface of the hardened solid cedar wood surface was ground with sandpaper having a particle size of # 30 to form minute fine recesses (first step).

Next, water was sprayed on the surface of the solid cedar material in which fine concave portions were formed, and water was applied so that the coating amount was 16 g / scale ² (second step).

  Subsequently, the solid-cedared cedar wood was passed once at a conveyance speed of 0.5 m / min between a pair of metal rolls of a roll press machine in which a clearance of 7.6 mm was set so that the compression rate was 16%. And compressed (third step). This amount of compression was sufficiently larger than the depth of the fine recesses on the surface of the cedar solid material formed in the first step.

  Then, the compressed solid cedar material was put into a dryer set at 80 ° C. and dried until the mass before watering was reached (fourth step).

  The obtained specimen of solid cedar before modification was designated as Example 3-1.

<Example 3-2>
A test piece of solid cedar (heartwood part) before modification obtained in the same manner as in Example 3 except that a sodium carbonate aqueous solution (alkaline aqueous solution) having a concentration of 1% by mass was used for water hammering in the second step. It was set as Example 3-2.

<Example 3-3>
A test piece of solid cedar (heart part) before modification obtained in the same manner as in Example 3 except that a surfactant aqueous solution having a concentration of 1% by mass was used for water hammering in the second step. It was set to 3.

<Comparative Example 3>
A test piece of 9 mm thick cedar solid material (core material part) before modification, in which the first to fourth steps were not performed, was referred to as Comparative Example 3.

(Test evaluation method)
The resin permeability of the test piece was tested and evaluated in the same manner as in Test Evaluation 1.

  Further, the water permeability of the test piece was tested and evaluated.

  Specifically, the test piece was cut out to 50 mm × 70 mm, the back side surface was covered with aluminum tape, and then the four-sided mouth end surface was covered and sealed with an epoxy resin.

  Next, the test piece was immersed in a constant temperature water bath adjusted to 20 ° C. for 3 minutes.

  Then, as the water permeation performance, the amount of water absorption per unit area was calculated by dividing the mass change before and after immersion by the area of the surface of the test piece.

(Test evaluation results)
Fig.5 (a) shows the test result of the penetration distance of an acrylic resin. Moreover, FIG.5 (b) shows the test result of the amount of water absorption.

  According to FIG. 5 (a), it can be seen that the effect of improving the resin permeability can be obtained even if an alkaline aqueous solution or a surfactant aqueous solution such as a sodium carbonate aqueous solution is used for water hammering.

  Moreover, according to FIG. 5 (a) and (b), the difference in resin permeability and water permeability is recognized by the kind of liquid used for water hammering. Therefore, it is considered preferable to change the type of liquid used for water hammering depending on the properties of the drug to be permeated.

[Test Evaluation 4]
The following test pieces of the composite material before modification were prepared. Each configuration is also shown in Table 4.

<Example 4>
Until a constant weight is reached at a temperature of 23 ° C. and a humidity of 50% of a composite material in which a 2 mm thick cedar rotary single plate (core part) and a 2.7 mm thick MDF are joined with an aqueous vinyl urethane resin adhesive Cured.

  First, the surface of the cured composite material on the rotary single plate side was ground with sandpaper having a particle size of # 30 to form minute fine recesses (first step).

Subsequently, water was sprayed on the surface of the composite material in which the fine recesses were formed, and water was applied so that the coating amount was 16 g / scale ² (second step).

  Subsequently, the composite material subjected to water hammering is transported at a speed of 0.5 m / min between a pair of metal rolls of a roll press machine in which a clearance of 4.4 mm is set so that the compression ratio of the rotary single plate is 16%. Compressed through one pass (third step). This amount of compression was sufficiently larger than the depth of the fine recesses on the surface of the composite material formed in the first step.

  And the compressed composite material was thrown into the dryer set to 80 degreeC, and it was made to dry until it became the mass before water hammering (4th process).

  The obtained specimen of the composite material before modification was designated as Example 4.

<Comparative Example 4-1>
Test of composite material before modification in which 2 mm thick cedar rotary single plate (core part) and 2.7 mm thick MDF were joined with an aqueous vinyl urethane resin adhesive without performing the first to fourth steps The piece was designated as Comparative Example 4-1.

<Comparative Example 4-2>
2mm thick cedar rotary single plate (core material part) and thickness which were subjected to the formation of fine recesses on the surface by the grinding of the first, second and fourth steps, water hammering and drying without performing the third step A test piece of the composite material before modification in which 2.7 mm MDF was joined with an aqueous vinyl urethane resin adhesive was defined as Comparative Example 4-2.

<Comparative Example 4-3>
A 2 mm thick cedar rotary single plate (core material part) and a 2.7 mm thick MDF which were formed by compressing the surface concave portions by the grinding in the first and third steps without performing the second and fourth steps. The test piece of the composite material before the modification in which the two were joined with an aqueous vinyl urethane resin adhesive was referred to as Comparative Example 4-3.

(Test evaluation method)
The test piece was evaluated for resin permeability.

  Specifically, after the surface of the back side of the test piece was covered with aluminum tape, the four-sided mouth end surface was covered with an epoxy resin and sealed, and the test piece was subjected to a day at a temperature of 23 ° C. and a humidity of 50%. After curing, a liquid ultraviolet curable acrylic resin was applied to the surface of the rotary single plate by a roll-type coating machine set to a clearance 0.6 mm smaller than the thickness of the test piece. The acrylic resin application was repeated until the mass of the test piece ceased to change.

  Next, the test piece coated with the acrylic resin was passed through a UV irradiator to completely cure the acrylic resin.

  Then, the test piece after the acrylic resin was cured was cut, the cross section was dyed with a toluidine blue solution, and the wood part and the resin part were applied separately, and the penetration distance of the acrylic resin was measured as the resin penetration performance by microscopic observation. .

(Test evaluation results)
FIG. 6 shows the test results of the penetration distance of acrylic resin.

  According to FIG. 6, it can be seen that the effect of improving the resin permeability can be obtained even in the composite material. Therefore, the thickness of the modified wood can be set arbitrarily.

  Moreover, according to FIG. 6, in addition to formation of a fine recessed part of a surface and compression, it turns out that water hammering and drying are essential.

  The present invention is useful for a method for producing modified wood.

C Crack L Liquid 10 Wood 20 Roll press machine 21 Roll

Claims (2)

A first step of forming fine recesses on the surface of the wood;
A second step of water hitting the surface of the wood in which fine recesses are formed in the first step;
A third step of compressing the wood hammered in the second step with a roll press so that the amount of compression is greater than the depth of the fine recesses on the surface of the wood;
A fourth step of drying the wood compressed in the third step;
A method for producing modified wood comprising: In the manufacturing method of the modified wood described in Claim 1,
The manufacturing method of the modified wood whose roll which contacts the surface of the water-washed wood in the roll press used at the said 2nd process is a hard resin roll or a metal roll.

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