JPH11151703A - Manufacture of modified timber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly inject a drug in a timber with a small amount of a chemical injection by pressure-injecting a solution for dissolving the drug in the timber to be fixed after a compression molding, and hence improving dynamic physical properties of the timber such as a conifer material or the like, thereby preventing a deformation such as a collapse or the like. SOLUTION: After a timber is compression-molded by a press molding machine by using a sealable mold, the timber 40a to be fixed by sufficiently cooling is contained in a pressure resistant container 20, and the container 20 is then evacuated to vacuum by a vacuum pump 25. Then, solution is introduced to be fully filled in the container 20, and a drug solution is then introduced by using a solution supply pump 13 until the container 20 becomes a predetermined pressure therein. In this case, the pressure drops in the container 20 due to invasion of the solution into the timber 40a. But, the introduction of the solution is continued to maintain a predetermined pressure in the container 20. Thus, the solution is press injected into the timber 40a, and the solution can be efficiently invaded into a center of the timer 40a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for injecting chemicals into compression-molded wood, and more particularly, to a method for efficiently injecting chemicals such as preservatives and flame retardants into conifers such as cedar and larch. In addition to increasing biodegradation and fire resistance,
The present invention relates to a method for producing excellent wood with improved mechanical properties.

[0002]

2. Description of the Related Art For example, a method of impregnating wood tissue with chemicals such as preservatives and insect repellents has been widely practiced as a means for suppressing biological deterioration of wood and increasing its useful life. Further, a fire retardant or the like may be impregnated in place of a preservative or an insect repellent to improve the fire resistance of wood. These drugs
It is used as a drug solution by dissolving or dispersing in water or an organic solvent.

As a method for efficiently impregnating a wood tissue with a chemical solution or the like, a reduced pressure / pressure injection method is known. In this depressurized / pressurized injection method, the wood to be treated is dried to an appropriate moisture content, placed in a closed container, and the pressure in the container is reduced to remove air in the wood structure. Then, the chemical is introduced into the closed container while maintaining the reduced pressure, and the chemical is injected under pressure into the wood tissue.

However, according to this method, when the size of the wood becomes a certain size or more, it becomes difficult to impregnate the center of the wood with the chemical. That is, when injecting a chemical solution into conifers or the like, since the pressure injection pressure is suppressed to about 10 atm in order to avoid deformation such as dropping, there is insufficient pressure for wood having a certain size or more. The chemical can only be injected near the mouth, and the chemical does not penetrate to the center of the wood. As a result, if such wood is cracked during use, the central part where the chemical is not injected is exposed and damaged by wood rot fungi and ants.

In order to improve this, prior to injecting the chemical into the wood, for example, a method of using so-called insizing wood, in which a large number of grooves having a depth of about 1 cm are engraved in the surface of the board material, for example, is adopted. Have been. However, in this insizing process, the surface design is impaired due to the puncture on the surface of the wood, and even if the thickness is more than several centimeters, the injectability into the wood is sufficient. Did not.

Another method of injecting a chemical solution into wood is a compression recovery method. In this compression recovery method, wood is compression-molded, a chemical solution is injected while the compressed state is temporarily held, and the injection of the chemical solution is promoted by using suction force due to recovery of the compression deformation of the wood. . For example, according to a paper in "Mokuzai Gakkaishi Vol. 41, No. 9, pp. 811-819", when impregnation of a chemical solution by a compression recovery method for a total of seven coniferous and hardwood species was attempted, the impregnation with the chemical solution was promoted in any case. It has been reported. However, although this compression recovery method slightly improves the problem of injectability of chemicals, it cannot be said that it is still sufficient, and furthermore, a large amount of chemicals is required to uniformly inject wood. For this reason, after injection, a large amount of solvent such as water in the chemical solution needs to be dried and removed from the wood, which requires a large amount of energy to remove, and is economically problematic.

An example of injecting a chemical solution into condensed softwood is disclosed in JP-A-3-24904.
According to this, after compressing a single cypress veneer having a thickness of about 1 mm, a specific water-soluble resin is impregnated and hardened to obtain a hinoki cypress reinforcing material that retains the original feel of wood.
However, as described in the above-mentioned publication, there is a problem that the cypress material subjected to the consolidation treatment is caused to return in the thickness direction at the time of absorbing moisture. To prevent this, it is necessary to inject and harden a specific resin liquid.

[0008]

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of such a situation, and a small amount of chemical solution is injected into wood such as softwood without causing deformation such as dropping. It is an object of the present invention to provide a method for producing modified wood that can uniformly inject a chemical into the wood and improve the mechanical properties of the wood.

[0009]

The invention according to claim 1 is
Modified wood characterized by comprising a step of compression-molding wood; a step of fixing the compression-molded wood; and a step of pressure-injecting a solution in which a drug is dissolved in the fixed wood. Pertaining to the method of manufacturing.

The invention according to claim 2 is characterized in that the total specific gravity of the immobilized wood is in the range of 0.45 to 0.85, and the invention according to claim 3 is characterized in that Characterized in that at least one of a preservative, an insect repellent, a flame retardant, and a resin is used.
The injection pressure is in a range of 15 to 30 atmospheres.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The method for producing modified wood according to the present invention comprises:
It consists of a compression molding step, a fixing step, and a pressure injection step. Hereinafter, each step will be described.

The compression molding step is performed to compress the wood to enhance its mechanical properties and to reduce the volume of the wood so as to reduce the amount of solution injected during the subsequent pressure injection step. In this compression step, it is necessary that the wood to be treated is appropriately dried to reduce the water content.
The degree of drying of the wood varies depending on the species of the tree, its size, the permeability of liquid into the tissue, and the like. In addition, when there is a possibility that cracks or the like may occur in the wood, some free water may be present. Note that free water in wood refers to water present in coarse pores such as tracheids without binding to wood constituents.
As a method for drying the wood, there are known a natural drying method in which the wood is left to dry in the atmosphere and an artificial drying method in which the water in the wood is evaporated at a controlled temperature and humidity. May be used.

The wood to be used may be any of softwood and hardwood. The form of the wood is preferably a board material, but may be a square wood or the like.

In the compression molding step, compression is performed after softening by heating. As a method, the wood is heated and softened in advance in a thermo-hygrostat or oven, and then compression-molded by a press molding machine.The wood is inserted between the platens of the heated press molding machine and fully heated and softened. After that, there is a method of compression molding. In the heat softening, the temperature of the wood must be higher than its softening point, and although it depends on the type of wood to be compression-molded, usually about 50 to 100 ° C is suitable. In the case where compression molding is performed at a temperature lower than the softening point of wood, a high pressure is required, and the fine structure of the wood is easily damaged by compression molding, and undesired phenomena such as a decrease in strength are easily caused. Become.

In the compression molding step, the wood is preferably compressed so that the total dry specific gravity of the wood is in the range of 0.45 to 0.85. The compression ratio for achieving this is approximately 20 to 60% when the total dry specific gravity of the wood before compression molding is about 0.35. Here, the total dry specific gravity is a characteristic generally used in the field of handling wood, and is specifically measured by the following method. That is, a test piece cut out to a predetermined size is dried in a well-ventilated dryer at a temperature of 100 to 105 ° C. until a constant weight is obtained in accordance with JIS Z2102, and the total dry weight (W) is measured. Similarly, the volume (V) of the dried specimen is measured, and the total dry specific gravity is determined from the ratio W / V of the two. In the case of a board material, the compression ratio refers to the percentage of the thickness reduced by compression with respect to the thickness before compression. For example, when a material having a thickness of 5 cm is compressed to a thickness of 2 cm, the compression ratio is (5-2) ÷ 5 ×
100 = 60 (%). Compressed wood having a compressibility in the above-mentioned range has improved mechanical properties and good injectability of a chemical solution. Also, compressing wood increases its specific gravity. The present inventors have conducted a detailed examination of the relationship between the compressibility and specific gravity of wood and the characteristics (mechanical properties and solution injection properties). As a result, there is a close relationship between the characteristics and the specific gravity. It has been found that the above characteristics are most preferably exhibited when the total dry specific gravity of the sample is in the range of 0.45 to 0.85. That is, when the total dry specific gravity of the compressed wood is less than 0.45, the mechanical properties are not sufficiently high, while when the total dry specific gravity is more than 0.85, the mechanical properties are high, but the mechanical properties are high. Poor injectability.

In the fixing step following the compression molding step, the compressed state of the wood is fixed, whereby the wood retains high mechanical properties for a long period of time. This is done in order to maintain the compressed state of the wood so that it can be performed in a small amount. In the fixing step, the compression-molded wood is heated while maintaining the compressed state, and then cooled while maintaining the compressed state to fix the compressed state of the wood.

There are the following modes of immobilizing compression-molded wood. One is, for example, in the above-mentioned compression molding step, after sufficiently cooling the wood that has been compression-molded by the press molding machine while maintaining its compressed state, take it out of the press molding machine, and in this subsequent fixing step, firstly, The wood is inserted between a pair of flat clamping dies, and the periphery of the dies is tightened with bolts or the like, so that the wood is completely set in contact with the clamping dies. Next, the wood thus set is placed in a pressure-resistant airtight container, and high-temperature and high-pressure steam is blown into the container to treat the wood with high-temperature steam.
After the treatment at a desired temperature for a desired time, the inside of the container is depressurized to normal pressure, the clamping die is taken out of the container together with the wood set therein, and the container is sufficiently cooled to be fixed. The wood is then removed from the clamping mold.

Another aspect of the mode of immobilizing the compression-molded wood is that in the compression molding step, the wood is compression-molded by a press molding machine using a mold that can be sealed, and then the immobilization is performed. In the step, the temperature of the platen of the mold is further raised while maintaining the above-mentioned compressed state, so that the inside of the mold is filled with high-temperature and high-pressure steam, and the compressed wood is treated under the high-temperature steam. Then, after processing at a desired temperature for a desired time, the wood is sufficiently cooled by cooling the platen surface, thereby immobilizing the wood. Then the pressure is released and the fixed wood is taken out.

By this fixing step, the return of the wood in the thickness direction is suppressed, so that it is not necessary to impregnate and harden the wood with a specific resin and fix it. Is not limited to a specific resin solution or a combination of the resin solution and a drug solution.

The pressure injection step is a step of pressurizing the compressed and immobilized wood with a solution in which a drug is dissolved and efficiently injecting the solution into the wood. As the chemicals used in the present invention, various chemicals known as wood modifying materials can be used. Among them, preservatives,
Insect repellents, flame retardants, and the like are desirable because they can improve particularly high demands on biodeterioration resistance and fire resistance. These drugs are uniformly dissolved in water and relatively low boiling organic solvents,
Alternatively, it is used as a finely dispersed solution.

The following is an example of the mode of the pressure injection step. First, the immobilized wood is accommodated in a pressure vessel, and the inside of the pressure vessel is evacuated by a vacuum pump. Next, after introducing the solution into the pressure-resistant container and filling the inside of the pressure-resistant container with the solution, a drug solvent is further introduced using a pressurized liquid sending pump until the inside of the pressure-resistant container reaches a predetermined pressure. As a result, the solution is pressed into the wood and efficiently penetrates to the center of the wood. At this time, the pressure decreases in the pressure vessel due to the infiltration of the solution into the wood, but the predetermined pressure is maintained by continuing the introduction of the solution into the pressure vessel. This allows the solution to be efficiently injected into the center of the wood.

The pressure at the time of injecting the solution is suitably 10 atm or more, particularly preferably 15 to 30 atm. By injecting under such high pressure conditions,
The solution is evenly injected into the center of the wood. In addition, when such high-pressure injection is performed on wood that is not subjected to compression molding, a drop in a soft portion such as an early wood or deformation of the entire wood occurs, but in the present invention,
Since the wood is sufficiently compressed and fixed in advance by the compression molding step and the fixing step to improve the mechanical properties, such dimensional change does not occur. However, if the injection pressure exceeds 30 atm, even if the wood is compressed and fixed, the wood is liable to undergo large deformation. Therefore, the injection pressure is preferably in the range of 10 to 30 atm.

Further, in the pressure injection step, the compression molded wood is fixed, so that even if a large amount of water enters the wood by the injection of the solution, the compression molded state is maintained. Therefore, wood can maintain high mechanical properties. In particular, when the solution is injected at a temperature higher than room temperature, the effect of maintaining the compressed state by this immobilization is remarkably exhibited.

Further, since the volume of the solution used for the injection into the wood is smaller than that before compression due to the compression and immobilization of the wood, a small amount of the solution may be used at the center of the wood. Can be evenly centralized. For example, when trying to uniformly inject a chemical solution into the interior of a cedar wood (total dry specific gravity 0.33) that has not been compression-molded, usually a solution of 167 kg (550 kg / m ³ per volume) per 100 kg of total dry wood weight is produced. It is necessary, but the volume is 1 /
If the wood is compressed and immobilized so as to be 2, it can be uniformly injected into the interior at a weight of 68 kg (450 kg / m ³ per volume) per 100 kg of total dry wood weight.

After keeping the wood in the solution in the pressure vessel for a required time, the introduction of the chemical solution into the pressure vessel is stopped and the chemical solution is discharged from the pressure vessel. Thereafter, the wood into which the solution has been injected is taken out of the pressure-resistant container and naturally dried or artificially dried or a combination of the two and dried so that the water in the wood has a desired moisture content. can get.

[0026]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a sectional view of a press molding machine in one embodiment of the method for producing modified wood of the present invention, and FIG. 2 is a schematic view showing a solution injection device in a pressure injection step.

As shown in FIG. 1, the press molding machine 50 used in the present embodiment includes an upper movable plate 55 and a lower fixed plate 56, and a pair of movable plates 55 and fixed plates 56 facing each other. The platens 51a and 51b are mounted, and a spacer 57 having a sealing packing is provided upright on the periphery of the platen 51b toward the platen 51a. The movable platen 55 is formed so as to be able to move up and down with respect to the fixed platen 56, and the platen 51a moves up and down together with the movable platen 55 so that the two platen plates 51a and 51b approach and separate from each other. I have.

The solution injection device shown in FIG. 2 has a solution tank 10 and a pressure-resistant container 20, and a solution L is supplied to the temperature controller 1 by a heater 11 provided in the solution tank 10.
2 is controlled to a desired temperature. Reference numeral 13 denotes a solution supply pump. The pressure vessel 20 includes a lid 21 for taking in and out the wood 40a, a pressure regulator 22, a temperature regulator 23, a pressure gauge 24, a vacuum pump 25, and a heater 2 for heating.
6 is provided.

(Example 1) The water content was 23 by artificial drying.
% Adjusted length 100cm, width 15cm, thickness 4cm
A specific gravity measurement test piece of 1 cm in length was cut out from both mouths of the Japanese cedar board material, dried in an oven at 105 ° C. to constant weight (total dryness), and the volume and weight of the specific gravity measurement test piece were measured to determine the specific gravity. Was. As a result, the total dry specific gravity was 0.33.

The remaining plate material 40 from which the specific gravity measurement test piece was cut was inserted between the platens 51a and 51b of the press molding machine 50 heated to 110 ° C., and after 30 minutes, the movable plate 5
5, the compression molding process was performed on the platens 51a and 51b. At this time, compression molding was performed by the thickness adjusting spacer 57 so that the sheet material 40 became 2.2 cm. Next, in the fixing step, the platen 51 is maintained while maintaining the compressed state.
a, 51b to 160 ° C.
The holding was performed for 0 minutes to perform an immobilization step. Next, the platens 51a and 51b were cooled to 40 ° C. while maintaining the compressed state, and then depressurized to take out the sheet material in which the compressed state was fixed. The obtained grained material had the same length and width as before compression molding, but had a thickness reduced to 2.2 cm (compression rate was equivalent to 45% of the original), and had cracks. No surface defects and good surface smoothness. A specific gravity measurement test piece having a length of 1 cm was cut out from both ends of the obtained board material and dried to a constant weight in an oven at 105 ° C., and then the specific gravity measurement test piece was measured for volume and weight to determine the specific gravity. , The total dry specific gravity was 0.60.

Then, a pressure injection step was performed as shown in FIG. 2 on the remaining plate material from which the specific gravity measurement test piece was cut off after the fixing step. In this example, a dye aqueous solution in which patent blue was dissolved at a concentration of 0.5% was used as the solution L so that the degree of penetration of the solution into the board material could be visually determined. First, the sheet material 40a that had been subjected to the fixing step was placed in a pressure-resistant container 20, and subjected to a pressure reduction treatment at a degree of vacuum of 25 mmHg by a vacuum pump 25 for 1 hour.
Next, the patent blue aqueous solution L is added to the solution tank 10.
From the pressure pump 20 using the supply pump 13.
After the inside of the pressure-resistant container 20 was filled with the solution L, the aqueous solution of patent blue L was further kept under pressure and maintained at 20 atm for 3 hours. Thereafter, the solution L in the pressure vessel is discharged and the pressure vessel 2
The pressure in 0 was gradually reduced to atmospheric pressure, and the sheet material subjected to the injection treatment was taken out. The removed strip material had no deformation or destruction such as dropping of the early part. Further, as a result of measuring the weight of the obtained board material, the amount of the solution injected was 68 g per 100 g of the total dry weight of the board material after immobilization.

The mesh material (injection-treated material, hereinafter the same) into which the solution was poured was naturally dried for 5 days, and then dried in an oven at 70 ° C. for 3 days to obtain a dried material having a water content of 23%. . As for this dried board material, the center part in the width direction was cut vertically along the fiber direction, and as a result of examining the dyeing condition of the straight grain surface inside the wood, the part close to Kiguchi was completely dyed,
Also, 80% of the area at the center in the length direction was dyed.

[0033] The flexural strength of the dried sheet material is determined by JIS.
74 N / mm ² when measured according to Z2101
On the other hand, it was 50 N / mm ² in the sheet material subjected to only the artificial drying before the compression molding, and in this example, the bending strength was increased by about 1.5 times as compared with that before the compression molding. I was

(Comparative Example 1) An example in which the compression molding step and the fixing step are omitted, and the pressure for injection is low. The length 100 in which the water content is adjusted to 24% by artificial drying
cm, width 15cm, thickness 4cm cut a specific gravity measurement test piece of length 1cm from both ends of the cedar board material, dried to constant weight in an oven at 105 ℃, measured the volume and weight of the specific gravity measurement test piece As a result of determining the specific gravity, the total dry specific gravity was 0.3
It was 5. The test piece consisting of the remaining Japanese cedar board material obtained by cutting the specific gravity measurement test piece from both lips was placed in the pressure-resistant container 20 without performing the compression molding step and the fixing step, and the same vacuum degree as in Example 1 was used. After performing a pressure reduction treatment at 25 mmHg for 1 hour, the pressure-resistant container 20 is filled with the aqueous solution of patent blue L, and the pressure of the aqueous solution of patent blue L is further maintained.
The pressure was maintained at 8 atm, which was lower than in Example 1, for 3 hours. Thereafter, the solution L in the pressure-resistant container 20 was discharged, the pressure in the pressure-resistant container 20 was gradually reduced to the atmospheric pressure, and the sheet material subjected to the injection treatment was taken out. The removed strip material had no deformation or destruction such as dropping of the early part. Also, as a result of measuring the weight of the board material, the injection amount of the solution L was 1% of the total dry weight of the board material.
The weight was 34 g per 00 g, which was half the amount of Example 1. Further, the infused sheet material was dried in the same manner as in Example 1 and the stained state of the straight grain surface inside the material was examined. As a result, only the kiguchi was stained, and the central part in the length direction was not stained. Was not stained at all.

(Comparative Example 2) Example in which the compression molding step and the fixing step were omitted, and the pressure and injection pressure were the same as in Example 1. Length 100c adjusted to 21% water content by artificial drying
m, width 15 cm, thickness 4 cm, cut out a specific gravity measurement test piece of 1 cm in length from both edges of a cedar board material, dried in an oven at 105 ° C. to constant weight, measured the volume and weight of the specific gravity measurement test piece The specific gravity was found to be 0.32
Met. The test piece consisting of the remaining cedar wood material obtained by cutting the specific gravity measurement test piece from both lips was put into the pressure-resistant container 20 without performing the compression molding step and the fixing step, and the degree of vacuum was 25 mmHg as in Example 1. , The pressure-resistant container 20 was filled with the aqueous solution of patent blue, and the aqueous solution of patent blue L was continuously injected under pressure and maintained at the same 20 atm as in Example 1 for 3 hours. Thereafter, the solution L in the pressure-resistant container L was discharged, the pressure in the pressure-resistant container was gradually reduced to atmospheric pressure, and the sheet material subjected to the injection treatment was taken out. The removed graining material had annual ring peeling and cracking, and was extremely destructive.

(Comparative Example 3) Example in which specific gravity after immobilization is high In the same manner as in Example 1, a length of 100 cm and a width of 15 c
m, a 4cm-thick sheet material is 1.4cm thick (compressibility is 6
(Corresponding to 5%), compression molding and immobilization were performed, and the total dry specific gravity after the immobilization was measured. The total dry specific gravity was 0.91. The aqueous solution of patent blue L was continuously injected into the sheet material in the same manner as in Example 1 and maintained at 20 atm for 3 hours. Thereafter, the solution L in the pressure-resistant container 20 was discharged, the pressure in the pressure-resistant container 20 was gradually reduced to the atmospheric pressure, and the sheet material subjected to the injection treatment was taken out. The removed strip material had no deformation or destruction such as dropping of the early part. Also, as a result of measuring the weight of the board material, the injection amount of the solution L was 14 g per 100 g of the total dry weight of the board material, and 68 g of Example 1.
About 1/5. Further, the material was dried in the same manner as in Example 1, and as a result of examining the dyeing condition of the grain surface inside the material, only the kiguchi was dyed, and the central part in the length direction was not dyed at all.

(Comparative Example 4) Example in which the total specific gravity after immobilization is low In the same manner as in Example 1, a length of 100 cm and a width of 15 c
m, a 4cm-thick sheet material is 3.4cm thick (compression rate is 1
(Corresponding to 5%), compression molded and fixed, and the total dry specific gravity after the fixation was measured. The total dry specific gravity was 0.38. An aqueous solution of patent blue was continuously injected into the sheet material in the same manner as in Example 1 and maintained at 20 atm for 3 hours. Thereafter, the solution in the pressure-resistant container 20 was discharged, the internal pressure was gradually reduced to atmospheric pressure, and the sheet material subjected to the injection treatment was taken out. The taken-out sheet material had deformation and destruction such as dropping, cracking, and compression of the early part.

Example 2 Water content 19 by artificial drying
%, A specific gravity measurement test piece of 1 cm in length was cut out from both ends of a cedar board material having a length of 80 cm, a width of 15 cm, and a thickness of 4 cm, and was dried to a constant weight in an oven at 105 ° C.
As a result of measuring the volume and weight of the test piece for specific gravity measurement and determining the specific gravity, the total dry specific gravity was 0.35. A compression molding step and a fixing step were performed in the same manner as in the example using the remaining cedar board material obtained by cutting out the specific gravity measurement test piece from both lips to produce a 2.2 cm thick board material. . A 1 cm long specific gravity measurement test piece was cut out from both edges of the panel material, and the total dry specific gravity after immobilization obtained by the same method as in Example 1 was 0.
63.

After the fixation, the pressure-injection step was performed as follows on the remaining sheet material obtained by cutting the test piece for specific gravity measurement. That is, the remaining plate material was placed in a pressure-resistant container 20 and subjected to a pressure reduction treatment with a vacuum pump 25 at a degree of vacuum of 25 mmHg for 1 hour. Then, the concentration of 5% by weight heated to 60 ° C.
Of boric acid aqueous solution L from solution tank 10 to supply pump 13
Then, the solution was fed to the pressure vessel 20 to fill the interior of the pressure vessel 20 with a boric acid aqueous solution. Then, while the pressure vessel 20 is being heated by the heater 26 installed on the outer periphery thereof, the boric acid aqueous solution L is further pressed into the pressure vessel 20 to maintain the pressure at 20 atm.
Maintained at 60 ° C. for 3 hours. Thereafter, the boric acid aqueous solution L in the pressure-resistant container 20 was discharged, and the sheet material subjected to the injection treatment was taken out. No deformation or cracking such as dropping of the early wood portion was observed in the removed sheet metal. As a result of measuring the weight of the obtained paneling material, the amount of the boric acid aqueous solution injected was 64 kg per 100 kg of the total dry weight of the paneling material. This corresponds to 3.2 kg per 100 kg of dry weight.

Next, the sheet material into which the boric acid aqueous solution was poured was naturally dried for 5 days, and then dried in an oven at 70 ° C. for 3 days.
Dried for days. The central portion of the dried board material in the width direction was longitudinally cut along the fiber direction, and the state of boric acid injection in the wood material was examined by a coloration method according to "Japanese Agricultural Standards for the Production of Softwood Lumber." That is, an ethanol solution of curcumin was applied to the cut surface and dried, and then a change in color was examined by applying a dilute hydrochloric acid aqueous solution of salicylic acid. As a result, the entire cut surface was colored red, and it was confirmed that boric acid was injected into the entire inside of the sheet material.

[0041]

As shown and described above, according to the method for producing modified wood of the present invention, a solution in which a drug is dissolved is injected into compression-molded and fixed wood by pressure. Wood with excellent physical properties can be manufactured. In addition, since the material is excellent in mechanical properties, even when a chemical solution is injected at a high pressure, deformation such as dropping of wood does not occur at the time of the injection. Furthermore, since the compression molded wood has a small void volume such as a tracheid, even when the solution is uniformly injected into the wood, the drying energy after the injection is reduced without excessive injection. it can. In addition, since the volume of the compression-molded wood is smaller than the original volume, the solution can be uniformly injected into the wood with a small solution injection amount, which is economical.

In the present invention, when the total dry specific gravity of the immobilized wood is in the range of 0.45 to 0.85, the mechanical properties of the obtained wood are excellent, and at the same time, the wood is excessively compressed. Therefore, the injection can be performed efficiently without the risk that the injectability of the solution is hindered during the pressure injection step.

Further, in the present invention, if the pressure of the solution is set to 15 to 30 atm, the solution can be efficiently injected into the compression-molded and fixed wood. Can be prevented from falling due to pressure.

[Brief description of the drawings]

FIG. 1 is a sectional view of a press molding machine in one embodiment of a method for producing modified wood according to the present invention.

FIG. 2 is a schematic view showing a solution injection device used in the pressurizing step in the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Solution tank 11 Heater 12 Temperature controller 13 Solution supply pump 20 Pressure-resistant container 21 Lid 22 Pressure controller 23 Temperature controller 24 Pressure gauge 25 Vacuum pump 26 Heater for heating 40, 40a Wood 50 Press molding machine 51a, 51b A pair of platens 55 movable board 56 fixed board

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tamio Arakawa 20 in Tanehata, Inoue-cho, Iwakura City, Aichi Prefecture Inside My Wood Co., Ltd.

Claims (4)

[Claims] 1. A step of compression-molding wood, a step of fixing the compression-molded wood, and a step of pressure-injecting a solution in which a drug is dissolved in the fixed wood. Method for producing modified wood. 2. The method for producing modified wood according to claim 1, wherein the fixed wood has a total specific gravity in the range of 0.45 to 0.85. 3. The method for producing modified wood according to claim 1, wherein the chemical is at least one of a preservative, an insecticide, a flame retardant, and a resin. 4. The method according to claim 1, wherein
A method for producing modified wood, wherein a pressurized injection pressure is in a range of 15 to 30 atm.