JPH10180717A - Method for injecting liquid into lumber, lumber, and woody composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inject liquid into lumber efficiently and economically by a method in which the lumber is compressed by pressurizing the liquid with the lumber kept at its softening point or above, the pressure of a container is reduced, the volume of the lumber is relaxed in the liquid, and the liquid is injected into the lumber. SOLUTION: Dried lumber 30 is put into a pressure container 20, after the lumber 30 being put into the container 20 in advance, the lumber 30 is immersed in liquid L which was introduced into the container 20. Next, the liquid L in the container 20 is pressurized by a liquid supply pump 13, the pressure of the container 20 is increased, and the lumber 30 is compressed by the pressure applied to the liquid L in the container 20 or by the hydrostatic pressure of the liquid L. Next, part of the liquid or part of pressurized gas in the container 20 is discharged to decrease the pressure of the container 20. In this way, the lumber 30 experiences the volume relaxation phenomenon and tries to regain the initial shape, suction force is generated in the process, and the liquid enters the tissue of the lumber.

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 a liquid into wood and to a wood and a wood-based composite material obtained by the method, particularly to a conifer such as cedar, larch, preservative, flame retardant, resin and the like. TECHNICAL FIELD The present invention relates to an invention for obtaining a wood and a wood-based composite material excellent in decay resistance, flame retardancy, and various physical properties by injecting a liquid containing water efficiently.

[0002]

2. Description of the Related Art For example, a method of penetrating a wood tissue with a chemical agent such as a preservative or an insect repellent has been widely practiced in order to suppress biological deterioration of wood and to increase its useful life. In addition, fire retardants and resins may be impregnated to improve the fire resistance and water resistance of wood. These agents and resins are used as liquids by dissolving or dispersing in water or an organic solvent.

[0003] As a practical method for efficiently penetrating a liquid into the wood tissue, a reduced pressure / pressure injection method is known. This reduced pressure / pressure injection method is to dry the wood to be treated to an appropriate moisture content, put it in a closed container, and reduce the pressure in the container to remove the cells contained in the wood and the air contained in the vessel, The liquid is introduced into the closed container while maintaining the reduced pressure, and the liquid is injected under pressure into the wood tissue.

[0004] However, the above-mentioned vacuum / pressure injection method is
Since this method involves pressurizing the pressurized liquid into the wood through thin cells and ducts from which air has been removed, there is great resistance when the liquid passes through the cells and ducts. In some cases, it takes a long time to inject the liquid, and it may not be possible to completely inject the liquid into the center of the wood.

[0005] Therefore, there has been researched a method of pretreatment of wood to change its microstructure to facilitate liquid injection. One of them is a compression recovery method. This method uses a mold to compress the wood to be treated in a direction perpendicular to the fiber axis to promote the separation and destruction of the closed wall hole in the vessel, and to form and expand an effective passage for liquid penetration. ,
By utilizing the suction force generated by moving the compressed wood from the mold into the liquid and recovering the shape (volume relaxation) in the liquid, the penetration of the liquid into the wood is promoted. For example, "Mokuzai Gakkaishi Vol. 41 No. 9 811-81
9 (1995), it is reported that liquid penetration was attempted by a compression recovery method for a total of seven coniferous and hardwood species, and that in all cases, liquid penetration was promoted.

However, in this compression recovery method, the compressed wood is cooled in a mold to form a treated wood temporarily kept in a compressed state, and the treated wood is removed from the mold. Since the wood is moved into the liquid, the shape of the wood is recovered in the liquid, and the liquid is injected by using the recovery force, at least the following six steps are required. 1) A step of loading wood to be treated into a mold. 2) adjusting the temperature of the wood to be treated to a predetermined temperature; 3) A step of compressing wood by operating a mold by hydraulic pressure or the like. 4) A step of cooling the wood in the mold while taking it out of the mold while maintaining the compressed state. 5) A step of immersing the wood to be treated, which is temporarily kept in a compressed state, in a liquid at a predetermined temperature and recovering the shape (volume relaxation) in the liquid. 6) Step of removing the wood after liquid injection.

As described above, in the current compression recovery method, the process of compressing the wood to be treated in the mold in advance, the process of temporarily maintaining the compressed state, and the process of compressing the wood to be treated from the mold into the liquid Is necessary, and the process is not only complicated as compared with the conventional decompression / pressure injection method,
There is a risk that the use of expensive molds and driving devices may increase the fixed cost, and the manufacturing cost increases, which is impractical. Further, there is a problem that the wood surface is easily damaged by the molds.

[0008]

DISCLOSURE OF THE INVENTION The present invention has been proposed in view of such a situation, and a method for efficiently and economically injecting a liquid into wood using a compression recovery method and a method therefor are disclosed. It is intended to provide the resulting wood and wood-based composites.

[0009]

According to the first aspect of the present invention, dry wood is placed in a pressure-resistant container, the wood is immersed in a liquid in the container, and then the wood is softened. Injecting the liquid into the wood by compressing the wood by pressurizing the liquid while maintaining the above temperature and then reducing the pressure in the container to reduce the volume of the wood in the liquid. The present invention relates to a method of injecting liquid into wood, which is a feature.

It is preferable that the temperature of the wood during the compression and volume relaxation in the liquid is maintained at a temperature equal to or higher than the softening point of the wood.

Further, after the dried wood is placed in a pressure vessel or after the wood is immersed in a liquid, the pressure in the pressure vessel is reduced to reduce the air in the wood. Alternatively, it is preferred to remove and then compress the wood by pressurizing said liquid.

The invention according to claim 4 to claim 9 is characterized in that, in any one of claims 1 to 3, the liquid to be injected into the wood is an aqueous solution containing boric acid or borate (claim 4), An aqueous solution containing a salt of an acid or polyphosphoric acid as a component (Claim 5), a wood preservative mainly composed of creosote (Claim 6), a low boiling organic solvent in which an organic wood preservative is dissolved (Claim 7), An aqueous solution containing one or more water-soluble dyes (claim 8), a monomer, a prepolymer or water containing a monomer and / or a prepolymer or a low-boiling organic solvent (claim 9).

[0013] Further, the invention according to claims 10 to 14 is a durable wood obtained by the method according to claims 4 to 8, wherein the corresponding components in the liquid are uniformly dispersed, and The invention according to claim 15 is
A wood-based composite material according to claim 9, wherein the monomer or prepolymer is uniformly dispersed in the material and then polymerized.

[0014]

According to the present invention, wood is compressed by the hydrostatic pressure (liquid pressure) of the liquid, the volume is reduced in the liquid (compression recovery), and the liquid is injected into the wood. Therefore, not only is the mold unnecessary, but the work of removing and attaching the wood to the mold and moving the wood from the mold into the injection liquid is eliminated, and the mold and its opening / closing drive device are used. Cost can be reduced.

Further, in the present invention, since the wood is compressed at a temperature higher than its softening point, the softened wood is compressed, and the compression can be performed easily and reliably.
Therefore, the closed wall hole in the vessel of the wood can be quickly and reliably peeled or broken by the compression, and the liquid can easily, reliably, and quickly penetrate into the wood in the subsequent volume reduction. In addition, as described in claim 2, if the volume of the wood is relaxed at a temperature equal to or higher than the softening point of the wood, the volume of the wood in the soft state is relaxed (compressed shape recovery). Since the wood can be recovered smoothly and closer to the original shape, a large liquid suction force is generated at that time, and the liquid can permeate the wood core even more efficiently.

Furthermore, if the dried wood is placed in a pressure-resistant container and then decompressed in the container before the compression, the dried wood is present in the cells and vessels. Reduces or eliminates air in the wood tissue, which is believed to interfere with the compression and volume relaxation of the wood and the penetration of liquids into the wood, thereby facilitating the compression and volume relaxation of the wood and further enhancing the liquid permeability be able to.

Further, if the liquid to be injected in claims 1 to 3 is specified as in claims 4 to 9, a particularly useful wood or wood-based composite material can be easily obtained. Furthermore, the wood according to claims 10 to 14 obtained according to claims 4 to 8 is one in which the components of the injection liquid are uniformly dispersed in the wood and has excellent durability. 2. The method according to claim 1, wherein the monomer or prepolymer uniformly dispersed in the wood is subsequently polymerized.
The woody composite material 5 has good physical properties due to polymerization of the monomer or prepolymer in the wood.

[0018]

DETAILED DESCRIPTION OF THE INVENTION The method of the present invention includes a step of compressing dried wood and a step of volume reduction. The process will be described below in the order of steps. In the compression step, the dried wood is placed in a pressure vessel, and the wood is immersed in a liquid introduced into the pressure vessel in advance or after the wood is placed in the pressure vessel. Next, the liquid in the pressure vessel is pressurized by means described later to increase the pressure in the pressure vessel, and the wood is compressed by the pressure applied to the liquid in the pressure vessel, that is, the hydrostatic pressure of the liquid. When this pressure reaches a certain level, compression of the wood structure begins to occur, and the rate of increase in the pressure in the pressure vessel decreases. The pressure at that time varies depending on the tree species, the degree of drying of the wood, the temperature, and the like. When the compression of the wood structure is almost completed, the pressure in the pressure vessel increases rapidly again. At this point, pressurization by the liquid is stopped.

The wood used in the compression step may be either coniferous or hardwood, and may be in the form of a log with cut branches and leaves, or a square or plate. Also, the bark may be on or off,
Those having no crack on the wood surface are preferred.

The wood used in this compression step must be appropriately dried. In addition, this "drying" means reducing moisture. This drying not only facilitates the operation of compressing the wood, but also makes it possible to smoothly permeate the liquid thereafter.
The degree of drying of the wood varies depending on the species of the tree, its size, and the permeability of the liquid into the tissue. Preferably, the wood is dried to a state where free water is not present in the wood, that is, a moisture content below the so-called fiber saturation point. In addition, when there is a possibility that the wood may be cracked, the presence of some free water is unavoidable. In addition,
Free water in wood is water present in coarse pores such as vessels without binding to wood constituents.

As a method for drying wood, there are known a natural drying method in which wood is allowed to dry in the air and an artificial drying method in which water in the wood is evaporated at a controlled temperature and humidity. It is also effective to use wood which has been compressed in a softened state, mechanically squeezed out of free water and then reduced in volume. In order to soften this wood structure, it is necessary to heat wood at a temperature higher than the softening point of lignin and hemicellulose.

The above-described liquid pressurizing method has the following modes. One is to first introduce a liquid into a pressure vessel containing dried wood so that the wood is covered by a sufficient amount of liquid in the vessel. Next, the liquid is further injected into the pressure vessel to fill the pressure vessel. When the wood is compressed by a desired amount by the filled pressurized liquid, the press-in of the liquid is stopped. Of course, a predetermined amount of the liquid may be put in the pressure container in advance, dried wood may be put in the pressure container, and then the liquid may be pressed into the pressure container.

In another embodiment of the above-mentioned liquid pressurization method, first, a liquid is introduced into a pressure-resistant container containing dried wood so that the wood is covered with a sufficient amount of liquid in the container. . Of course, a predetermined amount of the liquid may be put in the pressure vessel in advance. The term “sufficient amount of liquid” as used herein refers to an amount such that the wood is completely immersed in the liquid even after the liquid has penetrated into the wood by the volume relaxation phenomenon described later. Next, a pressurized gas such as air is introduced into the pressure vessel to increase the pressure of the liquid in the pressure vessel, and the wood is compressed by the pressure of the liquid. Then, when the desired compression amount is reached, the introduction of the pressurized gas is stopped.

The compressive pressure of the wood by the liquid is:
Depending on the water content and temperature of the wood, 10-30
It is preferred to be about kgf / cm ² . Further, the compression of the wood needs to be performed at a temperature equal to or higher than the softening point of the wood. When the compression of the wood is performed at a temperature lower than the softening point, not only is high cost required and uneconomical in terms of equipment and energy, but also the microstructure of the wood is easily damaged by the compression, and the strength is reduced. This is because it is easy to induce undesirable phenomena such as reduction. Desirably, the compression ratio of the wood achieved by this compression step is at least about 50%. However, the compression ratio of about 50% required for effective injection does not necessarily have to be achieved by one compression, and the compression / volume relaxation cycle may be divided into several. If there is a concern that the strength may decrease due to compression, as in the case of wood with many knots, for example, first compress by 20%, then inject the liquid by volume relaxation, then compress by another 20% and inject again by volume relaxation. In other words, compression of about 50% may be achieved as a whole.

The softening point of the wood depends on the tree species and the water content. Generally, wood having a water content near the fiber saturation point is about 80 to 100 ° C. For example, in the case of soft conifers such as Japanese cedar and larch, the water content near the fiber saturation point is sufficiently softened at 80 to 100 ° C. and 10 to 15 kgf.
It can be easily compressed to 40-50% of its original volume with a hydrostatic pressure of / cm ² .

In the next volume relaxation step, part of the liquid or pressurized gas in the pressure vessel is discharged to lower the pressure in the vessel. As a result, the wood undergoes a volume relaxation phenomenon and attempts to return to its original shape, in the process of which a suction is generated and liquid penetrates into the wood tissue. In order to smoothly cause the volume relaxation, the volume relaxation step is preferably performed at a temperature equal to or higher than the softening point of the wood. When the pressure in the pressure vessel is reduced while maintaining the temperature of the wood at or above the softening point, the volume of the wood recovers smoothly to almost the same level as before compression, and the liquid efficiently penetrates into the core of the wood. Moreover, in general, the softening point of wood having a water content near the fiber saturation point is about 80 to
At 100 ° C., at which temperature the viscosity of the liquid is significantly reduced compared to room temperature, so that the permeability of the liquid into the wood through the capillaries is further improved.

As the pressure in the pressure vessel in the volume relaxation step, an appropriate pressure is selected according to the type of wood, the water content, the temperature of the wood, and the like. The pressure in the container may be reduced to a predetermined value at one time, but at this time, it is preferable to keep the pressure in the container without lowering to normal pressure. Thereby, the effect of penetration of the liquid into the wood is maintained. Further, depending on the type and quality of the wood, if the pressure in the container is reduced at one time, the shape of the wood may not be restored well, or cracks may occur on the wood surface. Therefore, the pressure in the container may be reduced stepwise or continuously.

Next, the processed wood is taken out.
The work is performed by discharging the liquid remaining in the pressure-resistant container and taking out the wood from the container. The wood thus obtained is dried by a suitable method to obtain a product.

After the dried wood is placed in the pressure vessel, a pressure reduction step may be performed before the compression step to further enhance the penetration of the liquid into the wood after that. That is, it is considered that air is contained in cells and vessels of wood which have been dried to some extent, and this air prevents compression and volume relaxation of the wood, and further prevents penetration of liquid through the vessels and the like in the wood. Therefore, if the wood is placed under a reduced-pressure atmosphere to reduce or remove the air in the wood structure, the subsequent compression and volume relaxation of the wood are facilitated, and the permeability of the liquid is increased. This decompression step is performed in a pressure vessel, and the decompressed wood is directly used in the next compression step.

The present invention is characterized by uniformly injecting a liquid into wood, but its commercial purpose is to uniformly disperse wood preservatives, dyes, and the like into wood by a predetermined amount. It is an object of the present invention to increase the useful life of wood or to provide wood colored in a preferable color. In addition, by uniformly injecting and polymerizing a monomer or prepolymer into wood, it becomes possible to provide a composite material having excellent performance.

However, liquids that can be used in the present invention have limitations on thermal stability. That is, the liquid to be injected into the wood in the present invention depends on the injection temperature (usually 100 ° C).
(Around ℃) for a long time. Taking wood preservatives as an example, wood preservatives mainly composed of zinc and copper compounds that are widely used today cannot be used at high temperatures because metal compounds precipitate due to hydrolysis and the like. Conversely, boric acid, phosphoric acid, polyphosphoric acid and their ammonium salts and sodium salts, which provide a stable hot aqueous solution, can be easily and uniformly dispersed in wood in the form of an aqueous solution. Creosote, widely used as a wood preservative, is sufficiently stable at 100 ° C. and can be poured as it is. A wood preservative soluble in an organic solvent, such as chlorophenol, can be uniformly dispersed in wood by injecting it in a form dissolved in a low-boiling solvent and then recovering the solvent.

Here, "uniform distribution" will be described. When dissolving or dispersing wood preservatives in liquid, or when injecting liquid preservatives directly into wood, it is common to inject a concentration several times higher than that required for controlling bacteria and pests for safety. is there. Therefore, it is not necessary for the concentration to be evenly distributed inside the wood, and the chemicals can be distributed evenly throughout the lumber, even if there is a difference of several times between the high concentration (near Kiguchi) and the low concentration (middle of the lumber). Absent.
That is, the “uniform distribution” includes a state in which the drug is evenly distributed throughout the material as described above.
Such a uniform injection is difficult by the conventional method, and it is usually only about 10 cm from the tip and 10 to 20 mm from the side. Therefore, the difference between the conventional method and the injection method of the present invention is evident for a material having a length of 1 m or more and a small insertion dimension of a smaller one of the narrowest cross sections of the material.

The fact that wood preservatives, dyes, monomers and the like are uniformly dispersed in wood has great practical merits. For example, in the vacuum injection method, which is the most widely used injection method today, the distribution of the injected preservative or the like tends to be limited to the surface layer of wood. In this case, if the wood cracks during long-term use, or if holes are made in the wood for nailing or bolting, rot fungi enter the wood along with rainwater, and the inside of the wood that is not treated with preservatives In many cases, decay occurs. Such problems can be avoided by a uniform distribution of the preservative.

[0034]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows an example of a liquid injection device used in the method of the present invention. Reference numeral 10 denotes a liquid tank, 20 denotes a pressure vessel,
30 is wood. The liquid tank 10 includes a heater 11, and the liquid L is controlled to a desired temperature by a temperature controller 12. Reference numeral 13 denotes a liquid supply pump. Also,
The pressure vessel 20 has a lid 2 for taking in and out the wood 30.
1, a pressure controller 22, a temperature controller 23, a pressure gauge 24, a vacuum pump 25, and a heater 26 for heating a liquid. Next, an embodiment of the present invention using this apparatus will be described. In order to more remarkably show the effects of the present invention, a comparative example is shown in which the compression step and the volume relaxation step of wood are performed at a softening point or lower.

(Example 1) The moisture content was 23 by natural drying.
The wood 30 made of peeled cedar logs having a terminal end diameter of 17 cm and a length of 70 cm adjusted to% was put in the pressure-resistant container 20, the degree of vacuum was kept at 25 mmHg by the vacuum pump 25, and a pressure reduction step was performed.

Next, the liquid L (staining liquid: 0.5% aqueous solution of patent blue) heated to 90 ° C.
From 0, the pressure vessel 20 was filled with the supply pump 13. A heater 2 having the pressure vessel 20 installed on the outer periphery thereof
While heating at 6, the liquid is maintained at an internal pressure of 1 atm and a liquid temperature of 85 to 95 ° C., that is, a temperature equal to or higher than the softening point (80 ° C.) of the wood 30 for 60 minutes. L was pressed into the container 20 to perform a compression step. At this time, the pressure in the pressure vessel 20 started to rise with the injection of the liquid L, but the pressure was reduced to about 10 due to the compressive deformation of the wood structure.
At the time when the pressure reached the atmospheric pressure, the pressure rising speed became gentle. Further, the liquid L was continuously injected until the pressure became 32 atm, and then the liquid temperature was maintained at about 90 ° C. for 5 minutes at the same pressure.

Thereafter, a part of the liquid L in the pressure vessel 20 was discharged to lower the internal pressure to 8 atm, and a volume relaxation step was performed.
Then, after maintaining the same pressure for 30 minutes, the heating of the heater 26 was stopped, all the residual liquid was returned to the tank 10, and the wood 30 was taken out of the pressure-resistant container. The circumferential surface of the obtained wood showed some deformation, but the diameter was almost the same as the original log. The weight increase in this state was 130% of the original log weight. The entire surface of the obtained wood was dyed blue, and no cracks were found inside. In addition, when the central part in the length direction was cut and the wood opening was observed, it was confirmed that both the sapwood part and the heartwood part were dyed blue, and the dyeing solution was uniformly injected.

(Comparative Example) The water content was 30% by natural drying.
The peeled cedar log having a diameter of 15 cm and a length of 60 cm adjusted in the above manner was placed in a pressure-resistant container 20, and was left for 60 minutes at a degree of vacuum of 25 mmHg by a vacuum pump 25. Next, the liquid L (staining liquid) at room temperature is poured from the liquid tank 10 into the pressure-resistant container 20.
And press-fitted until the internal pressure reached 32 atm. After maintaining this state for 5 minutes, the internal pressure was increased to 8 in the same manner as in Example 1.
The pressure was reduced and maintained for 60 minutes. Next, the residual liquid was discharged, and the log was taken out. The increase in weight of this log was 70% of the original log weight. When cutting the central part in the length direction and observing the kiguchi surface, most of the sapwood part was dyed, but the heartwood part was not dyed.

(Example 2) Using the same wood as in Example 1, a liquid L was injected into the wood in the same manner except for the depressurization step.
In the obtained wood, although the dyed state of the heartwood part was somewhat lighter than that of Example 1, almost the whole was uniformly dyed.

(Example 3) Cut out from the cedar heartwood portion, and the water content was adjusted to 26% by natural drying, and the radial direction was 50 m.
m, a tangential direction of 150 mm, and a length of 800 mm were placed in a pressure-resistant container 20, and the inside of the container was evacuated to 25 mmHg by a vacuum pump 25. Next, the liquid L (stained liquid: 0.5% aqueous solution of patent blue) heated to 95 ° C. was filled from the liquid tank 10 into the pressure-resistant container 20 using the supply pump 13. The wood was softened while maintaining the internal pressure at 1 atm and the liquid temperature at 90 to 95 ° C. for 60 minutes while heating with the heater 26 installed on the outer periphery of the pressure-resistant container 20. While the heating was continued, the liquid L was again injected into the pressure vessel 20 from the liquid tank 10. When the pressure in the pressure vessel 20 reached about 18 atm, the injection of the liquid L was stopped and maintained at the same pressure for 60 minutes. .

Thereafter, a part of the liquid L in the pressure vessel 20 was discharged to return the internal pressure to 8 atm. After a lapse of 30 minutes, the heating of the heater 26 is stopped, and all the residual liquid L is removed from the tank 10.
And the board material was taken out. The weight increase in this state was 110% of the original board material. The obtained paneling material was almost the same as the original dimensions except that the radiation direction was slightly reduced. Further, the entire surface of the board material was dyed blue. When the central part in the length direction was cut and the kiguchi surface was observed, the whole was stained blue, and it was confirmed that the stain was uniformly injected.

(Examples 4 to 12) Commercial cedar, rice pine,
Four surfaces of a square pillar (heartwood, length 4 m) of rice hemlock were dropped with a planar, and the cross section was set to 100 × 100 mm. Cut off about 150mm both ends of each prism, 900mm length from the rest
4 test pieces were cut out. At this time, the moisture content was determined from the end pieces having a thickness of about 20 mm collected between adjacent test pieces by a completely dry method. Two adjacent specimens are paired.
The book was used as an injection example of the present invention, and the other was used as a comparative example by a vacuum pressurization method. The experimental conditions and results are shown in Table 1.

[0043]

[Table 1]

At the time of injection according to the present invention, the test specimen was first placed in a pressure-resistant container 20, and the inside of the container was adjusted to 25 mmHg by a vacuum pump 25. Next, the injection liquid (aqueous solution) heated to 95 ° C. is filled from the liquid tank 10 into the pressure-resistant container 20 using the supply pump 13, and the liquid temperature is adjusted to the injection temperature described in the first item by the operation of the heater 26 and the temperature controller. did. After the test piece was heated and softened at a predetermined injection temperature for 90 minutes, 9
The injection liquid adjusted to 5 ° C. is pressed into the pressure-resistant container 20, and the pressure is increased while compensating for the decrease in the volume of the test specimen due to the compression.
After reaching the maximum pressure shown in the table, the pressure was held for the holding time shown in Table 1. Then, a part of the injection liquid in the pressure-resistant container 20 was discharged, and the injection liquid was injected into the test body while maintaining the internal pressure at the injection pressure shown in Table 1 for a predetermined time. When the injection pressure was at least two levels, the pressure was decreased stepwise, and each pressure was maintained for the injection time shown in Table 1. At the same time after the completion of the injection, the power of the heater 26 was turned off, and if necessary, the temperature of the injection liquid was lowered to 95 ° C., and then the remaining part of the injection liquid was returned to the liquid tank 10, and the specimen was taken out.

In Comparative Examples 4 to 11, the test specimen was placed in a pressure-resistant container 20 at room temperature, and the pressure was reduced to 25 mmHg. Then, the injection liquid at room temperature was filled from the liquid tank 10 into the container by the supply pump 13, and further press-fitting was continued. After maintaining the pressure at 15 kg / cm ² for 2 hours, the injection liquid was returned to the tank, and the specimen was taken out.

The injection of creosote oil in Example 12 was performed in the following procedure. The test piece was softened by being treated in a thermo-hygrostat controlled at 95% humidity and 90 ° C. for 2 hours.
This was fixed to the bottom of a stainless steel tank having an inner size of 200 × 200 × 200 mm, filled with creosote oil heated to 90 ° C., and the whole was put into a pressure-resistant container 20 adjusted to 90 ° C. in advance, and compressed air was introduced. Then, the inside of the container was pressurized to 20 kg / cm ² and held for 30 minutes. Then, a part of the air in the pressure-resistant container 20 was discharged to reduce the internal pressure to 10 kg / cm ² ,
After holding for 0 minutes, the internal pressure was returned to normal pressure, the stainless steel tank was taken out, and the test specimen was collected. In a comparative example corresponding to Example 12, a test piece heated and softened to 70 ° C. in the same procedure was used at 70 ° C.
Then, the specimen was taken out by pressurizing with compressed air to 10 atm in a state of being immersed in creosote oil and keeping the pressure for 2 hours.

The distribution of the injection solution in Table 1 was evaluated as follows. When the injection solution is a boric acid aqueous solution, the test specimen is dried with a hot air dryer at 80 ° C. for 3 days, and then the test specimen is vertically divided into two pieces by a circular saw, and the curcumin coloring liquid is sprayed on the cross section, and the whole is uniform. Is orange when the sample is orange.
In the case of a polylinsan-based injection solution, the specimen was dried in hot air at 80 ° C. for 3 days, and then 5 cm from the center of the vertically divided specimen.
A 20 × 20 m plate sample was cut out, dried completely, and
The presence of phosphorus was assayed by X-ray fluorescence analysis, and if it was clearly present, it was judged to be a homogeneous injection. In the case of creosote, the test specimen was left at room temperature for several weeks, then divided vertically, and the uniformity of infiltration was confirmed visually.

In Table 1, since the injection amount of Example 5 was smaller than that of Example 4, the test piece was compressed in the injection solution,
It is not preferable to release the total pressure immediately, and it is more effective to gradually reduce the pressure. In the comparative example, the injection amount was generally small, but as a result of vertically dividing and observing the test piece, the injection was almost stopped at 10 cm or less from the wood opening.

(Embodiment 13) A cross section of 105 × 105 mm,
A cedar prism (with a center) having a length of 900 mm and a water content of 23% was placed in the pressure-resistant container 20. Separately, an acetone solution containing 2% by weight of pentachlorophenol is prepared in the liquid tank 10,
The temperature was adjusted to 55 ° C (liquid L). The pressure L container 20 is filled with the liquid L using the supply pump 13 and the pressure in the container is set to 5 kg /
After controlling the internal temperature to 90 ° C. by controlling the liquid heater 26 while controlling the temperature to not more than cm ² , the heating was continued for 60 minutes.
Next, the liquid L is pressed into the pressure-resistant container 20 by the supply pump 13 and maintained at this pressure for 10 minutes when the internal pressure reaches 25 kg / cm ^2.
It was lowered to 0 kg / cm ² and held for 60 minutes. Then, the internal pressure was returned to normal pressure, the residual liquid was returned to the liquid tank, and the test specimen was taken out. The test piece was vertically divided into two pieces along the central axis, and then air-dried for 10 days. Then, on the center line of the test specimen, 5 cm from two points of 10 cm and 45 cm (central part) from the mouth
A test piece of L × 20 mmT × 20 mmR was cut out and subjected to X-ray fluorescence analysis using intrinsic X-rays of chlorine atoms. From the comparison of the obtained peak areas, the concentration of pentachlorophenol at the center was about 80% of the concentration at 10 cm from Kiguchi.
It was found that the liquid injection was very uniform.

[0050]

As shown and described above, according to the present invention, when a liquid is injected into wood, a mold is not used for compressing the wood. Not only does it save labor, but also eliminates the need for a mold and devices for opening and closing the mold, thereby making it possible to reduce costs and manufacture economically. Also, the penetration of the liquid into the wood compresses the wood by the hydrostatic pressure of the liquid in the pressure vessel,
Thereafter, since the volume of the wood is reduced by reducing the pressure in the container, the liquid is quickly injected into the wood structure. Moreover, at this time, since the wood is compressed while maintaining the temperature of the wood above the softening point, the amount of deformation during compression and volume relaxation is large, and the liquid can be reliably injected into the core of the wood. In particular, when the wood is kept at a temperature equal to or higher than the softening point even during volume relaxation, the liquid can be more efficiently and reliably injected into the wood. Further, since the wood does not come into contact with the mold, the surface is not damaged, and a wood molded product having a high commercial value can be obtained. Furthermore, if the wood is compressed with a liquid after the pressure in the pressure vessel is reduced, the air that remains in the wood structure and prevents the compression and volume reduction of the wood and hinders the infiltration of the liquid is reduced or removed. It can be more efficiently penetrated into wood.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of a liquid injection device for performing a method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Liquid tank 11 Heater 12 Temperature controller 13 Liquid supply pump 20 Pressure-resistant container 21 Lid 22 Pressure controller 23 Temperature controller 24 Pressure gauge 25 Vacuum pump 26 Heater for liquid heating 30 Wood

Continuing on the front page (72) Inventor Tamio Arakawa 20 Myanedo Co., Ltd.

Claims (15)

[Claims] 1. Putting dry wood into a pressure-resistant container so that the wood is immersed in the liquid in the container, and then pressurizing the liquid while maintaining the temperature of the wood at or above the softening point. A method of injecting the liquid into the wood by compressing the wood by the method, and thereafter reducing the pressure in the container to reduce the volume of the wood in the liquid. 2. The method according to claim 1, wherein the temperature of the wood is maintained at a temperature equal to or higher than the softening point of the wood when the wood is compressed and the volume is relaxed in the liquid. 3. The pressure in the pressure vessel according to claim 1 or 2, wherein the dried wood is put in a pressure vessel, or after the wood is immersed in a liquid, the pressure in the pressure vessel is reduced to reduce or remove air in the wood. And then compressing the wood by pressurizing the liquid. 4. The method according to claim 1, wherein
A method for injecting a liquid into wood, wherein the liquid to be injected is an aqueous solution containing at least boric acid or borate as an essential component. 5. The method according to claim 1, wherein
A method for injecting liquid into wood, wherein the liquid to be injected is an aqueous solution containing at least a salt of phosphoric acid or polyphosphoric acid as a component. 6. The method according to claim 1, wherein
A method for injecting a liquid into wood, wherein the liquid to be injected is a wood preservative mainly composed of creosote. 7. The method according to claim 1, wherein
A method for injecting a liquid into wood, wherein the liquid to be injected is a low-boiling organic solvent in which an organic wood preservative is dissolved. 8. The method according to claim 1, wherein
A method for injecting a liquid into wood, wherein the liquid to be injected is an aqueous solution containing one or more water-soluble dyes. 9. The method according to claim 1, wherein
A method for injecting a liquid into wood, wherein the liquid to be injected is a monomer, a prepolymer or water containing a monomer and / or a prepolymer or a low-boiling organic solvent. 10. Wood with excellent durability, characterized in that the wood preservative containing at least boric acid or borate as a component obtained according to claim 4 is uniformly distributed in the material. 11. Wood with excellent durability, characterized in that the wood preservative comprising at least a salt of phosphoric acid or polyphosphoric acid obtained according to claim 5 is uniformly distributed in the material. 12. Wood with excellent durability, characterized in that the wood preservative mainly composed of creosote obtained according to claim 6 is uniformly distributed in the material. 13. Wood with excellent durability, characterized in that the organic wood preservative obtained according to claim 7 is uniformly distributed in the material. 14. Wood with excellent durability, characterized in that one or more water-soluble dyes obtained according to claim 8 are uniformly distributed in the material. 15. A wood-based composite material according to claim 9, wherein the monomer or prepolymer is uniformly dispersed in the material and then polymerized.