JPH0825311A - Antisepticizing method of wood - Google Patents

Abstract

PURPOSE:To employ glued laminated wood, which is laminating a plurality of sawn boards to one another through an adhesive, as wood and modified creosote oil, which is obtained by further redistilling the creosote oil obtained by fractionally distilling coal tar, as antiseptic so as to obtain excellent antiseptic effect without swelling. CONSTITUTION:The antisepticizing method of wood for fircibly impregnating the wood with antiseptic is performed by pressurizing the interior of a pressure vessel, which is charged with the antiseptic, under the condition that the wood is installed in the pressure vessel. As the wood, glued laminated wood, which is produced by laminating a plurality of sawn boards to one another through adhesive, is employed. Further, as the antiseptic, modified creosote oil, the boiling point of which is brought into the range of 200-300 deg.C by redistilling creosote oil, is employed. The creosote oil is obtained by removing acid component through alkali extraction from naphthalene oil, which is obtained by distilling coal tar by-produced during the manufacturing of coke by means of the carbonization of coal at ordinary pressure or under reduced pressure, so-called washing oil, which is the fraction within the boiling point range of 200-300 deg.C, and further, removing naphthalene by distillation from the oils.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wood preservative treatment method for imparting wood preservative and insect repellent properties.

[0002]

2. Description of the Related Art When wood is applied as a structural material to a building, lumber products have been the mainstream for a long time, but recently laminated wood has attracted attention. Laminated wood is a wood-based material that is obtained by drying a laminated board (lamina) of a specified thickness, then removing defects such as knots in some cases, and sticking the fibers in parallel with each other with an adhesive. As a result of the dispersion and removal of, the quality is stable with less variation than ordinary lumber.

[0003] In the present day when large-diameter trees are becoming increasingly scarce, natural materials cannot be obtained at all by laminating using lamina that is relatively thin and not so long and cascading lamina by various joint methods. It is also possible to make a huge laminated lumber. Therefore, it is becoming more and more difficult to obtain a lumber product having a large cross section and a long size in terms of price and conservation of the natural environment, so that the demand for laminated lumber tends to increase.

By the way, the laminated wood has many advantages as described above, but since it is originally a wood-based material, it has a drawback that it deteriorates when it is used outdoors or in contact with water for a long period of time. ing. Since the spread of laminated lumber in Japan is relatively new and its use was limited to structural materials and decorative materials applied indoors, the deterioration of laminated lumber was not seen as a problem in recent years. Increasingly, laminated wood is being used in environments where it is frequently exposed to water, such as external structural materials of exposed structures and bridges.

[0005] Usually, the surface of the laminated wood which is placed in such a perishable environment as described above is coated with an antiseptic / insecticide agent (hereinafter referred to as an antiseptic).
When exposed to wind and rain, the antiseptic agent will be leached out, the wood will be cracked, and the untreated interior will be exposed, so it is almost impossible to expect antiseptic and insecticidal effects (hereinafter referred to as antiseptic effects). . For this reason, it is desirable that the preservative is impregnated into the laminated material by so-called pressure injection in which the preservative is forcibly penetrated into the inside.

When the preservative treatment is carried out by the pressure injection method as described above, a water-soluble preservative is generally applied to a foundation material for construction such as a foundation, which is directly applied. Oil-based creosote oil is applied to railroad sleepers and the like, which are less likely to come into contact with people.

[0007]

Therefore, it is conceivable to pressurize the above water-soluble preservative into laminated wood as a target, but as mentioned above, the laminated wood is made by interposing the dry lamina with the adhesive. When laminated with a water-soluble preservative, the lamina that make up the laminated material swells and swells, cracks, and peeling on the adhesive surface occur. . In particular, the swelling rate of timber differs greatly depending on the direction of the timber, such as the tangential direction of the annual ring and the radial direction from the center. Becomes extremely non-uniform, which promotes the cracking and peeling. Therefore, it is not preferable to use a water-soluble preservative in the preservative treatment of the laminated wood.

Therefore, in order to apply the preservative pressure injection method to the laminated wood, it is conceivable to use an oil-based preservative or an oil-soluble preservative as the preservative. While oil-based preservatives are themselves preservatives like creosote oil,
The oil-soluble preservative is a drug having an antiseptic effect dissolved in an organic solvent such as kerosene or xylene.

Even if the laminated material is impregnated with these oil-based and oil-soluble preservatives, the lamina constituting the laminated material does not swell, so that the preservative of the pressure injection method for the laminated material is used. Suitable as an agent.

However, the creosote oil has a black color, is dirty, is sticky to the touch, has a strong offensive odor, and has a so-called sweating action that exudes from the surface of the wood during the hot summer months. This is uncomfortable for humans and is unsuitable for most applications that often come into contact with humans.

The oil-soluble antiseptic agent generally has a beautiful finished state, but the antiseptic component in the antiseptic agent is a small amount of 0.5 to 5% by weight, and the balance is solvent. Yes, since this solvent is a carrier for permeating the antiseptic component, the solvent volatilizes and exposes only a trace amount of the antiseptic component when the wood to which the oil-soluble antiseptic is injected under pressure is exposed to the outside air for a long period of time. It becomes a state. Also, the remaining antiseptic components are often exposed to sunlight, rain, and temperature outside, and are subjected to actions such as volatilization, leaching, and decomposition, and their effectiveness is reduced and disappears in many cases.

Further, the above antiseptic component and the organic solvent as a carrier are both expensive in Japan.
Therefore, the fact is that the pressure injection method applying an oil-soluble preservative to laminated wood has not been put into practical use.

The present invention has been made in order to solve the above-mentioned problems. Even when laminated wood is used as wood, it does not swell, and it is excellent in preservative effect. The purpose is to provide an antiseptic treatment method.

[0014]

According to the method of preserving wood according to claim 1 of the present invention, the wood is put in a pressure vessel filled with a preservative, and the inside of the pressure vessel is pressurized so that the preservative is preserved. In a wood preservative treatment method in which a wood is forcibly impregnated with an agent, a laminated wood in which a plurality of sawing boards are laminated with an adhesive as the wood is used, and coal tar is obtained by fractional distillation of the preservative. The modified creosote oil obtained by redistilling the obtained creosote oil is further used.

The method of preserving wood according to claim 2 of the present invention is the method of preserving wood according to claim 1, wherein the modified creosote oil is 200% of the creosote oil.
It is characterized in that it is a distillate having a temperature of 300 ° C to 300 ° C.

[0016]

According to the wood preservative treatment method of the first aspect, the modified creosote oil obtained by redistilling creosote oil is used as the preservative. Since such a modified creosote oil is a so-called oil-based preservative, even if a relatively thin wood such as a lumber is impregnated with the modified creosote oil in the preservative pressure injection step, the wood is preserved. Does not swell, so even if laminated wood is applied as wood, cracking and peeling do not occur in the laminated wood, and it is possible to perform antiseptic treatment by pressure injection method without dimensional deviation .

According to the wood preservative treatment method of claim 2, the modified creosote oil is a fraction of 200 ° C. to 300 ° C. obtained by redistilling the creosote oil. Therefore, the modified creosote oil of such a fraction has almost transparent color instead of black which gives a dirty appearance, has less offensive odor, and contains carcinogenic substances such as benzopyrene. Therefore, the laminated wood impregnated with such modified creosote oil does not cause discomfort.

Further, the modified creosote oil of the above fraction has the same antiseptic effect as that of the creosote oil, even though the coloring component and the offensive odor generating component are removed from the creosote oil. The antiseptic effect lasts for a long time because it is uniformly impregnated by the pressure injection operation.

In addition, since the modified creosote oil as described above is significantly cheaper than other types of oil-soluble preservatives, it is possible to significantly reduce the material cost for preservative treatment. Therefore, it is possible to put on the market an antiseptic laminated wood product at a low cost.

[0020]

The present invention relates to a wood preservative treatment method in which wood is loaded into a pressure vessel filled with a preservative and the pressure in the pressure vessel is forced to impregnate the wood with the preservative. Is. In the present invention, the laminated wood in which a plurality of lamina are laminated via an adhesive is applied as the wood. The type of laminated wood is not particularly limited, but in the present embodiment, a plurality of lamina, which are lumbered to a thickness of about 20 mm, are pasted together with an adhesive applied.

As the above-mentioned adhesive, resorcinol resin-based adhesive, urea resin-based adhesive, melamine resin-based adhesive, phenol resin-based adhesive, α-olefin resin-based adhesive, isocyanate-based adhesive, etc. are preferably applied. It is possible.

Next, a modified creosote oil obtained by redistilling creosote oil is applied as the preservative. More specifically, the boiling range is 200
C. to 300.degree. C. is applied. On an industrial scale, the creosote oil has a boiling point range of 200 ° C. to 300 ° C. called naphthalene oil and washing oil obtained by distilling coal tar by-produced during coke production by dry distillation of coal under atmospheric pressure or reduced pressure. Removes acid components such as phenol and cresol from the fraction by alkali extraction,
Further, it is obtained by removing naphthalene by distillation. The yield of creosote oil thus obtained based on coal tar is about 10%.

The acidic components such as phenol and naphthalene are separated and recovered for industrial use as active components, but removal of these components does not adversely affect the antiseptic performance of the creosote oil. Rather, the removal of naphthalene has the effect of preventing the precipitation of crystals, and the acid component lowers the weather resistance of the creosote oil because it is water-soluble. Therefore, the removal of the acid component is preferable in terms of the performance of the creosote oil.

Then, the above-mentioned creosote oil is further redistilled and the fraction at 200 ° C. to 300 ° C. is taken out to obtain the modified creosote oil according to the present invention. By performing the redistillation, the coloring component and the odorous component are removed, and the substance is almost colorless and transparent and has no peculiar odor, and also harmful components such as benzopyrene are removed.

The components of creosote oil are naphthalene, cresol, higher phenols, naphthols, etc. By redistilling the above creosote, coloring components and odorous components in the above components are removed, It becomes almost colorless and transparent and has no peculiar odor, and harmful components such as benzopyrene are also removed.

Further, in the present invention, such a modified creosote oil is used as an antiseptic, the modified creosote oil is filled in a pressure vessel loaded with laminated wood, and then, in a pressure vessel in a sealed state. Is applied to impregnate the laminated wood with the modified creosote, and the laminated wood is subjected to antiseptic treatment.

Regarding pressurization injection of such a preservative,
For example, it is defined in detail in JIS standard A9002-1992, and the apparatus described in this standard is applicable to the present invention. The antiseptic treatment of laminated wood using this device will be described below.

FIG. 1 is an explanatory view of a pressure type antiseptic treatment apparatus described in the above JIS standard. The above JIS
Although water-soluble preservatives are specified in the standard, in the present invention, the modified creosote oil is used instead of the water-soluble preservatives. As shown in the figure, the antiseptic treatment device 10 stores a chemical can 20 into which wood (precipitated lumber in the present invention) to be preservative is charged and a preservative (modified creosote) to be injected into the laminated lumber. Storage tank (working layer) 30, a dissolution tank 40 for adjusting the preservative to a predetermined concentration, and a measuring tank 50 for measuring the amount of the preservative consumed at the time of the pressurizing step and at the end. .

Then, as shown in FIG.
Predetermined piping is arranged between the storage tank 30, the dissolution tank 40, and the measuring tank 50, and valves are provided at various places of the piping so that the antiseptic treatment apparatus 10 can be operated by operating the valves. . Specifically, the liquid feed pump 30
The preservative in the storage tank 30 is introduced into the dissolution tank 40 by the operation 1 and the adjusted preservative after the concentration adjustment is introduced into the measuring tank 50 by the operation of the liquid feed pump 401.

After a predetermined amount is measured in the measuring tank 50, a pressurizing pump 501 is operated to supply a predetermined amount of an antiseptic agent and a laminated material in advance.
Will be introduced to. It should be noted that the charging of the laminated material into the drug-filling can 20 is performed by a lid 20 having a sealable structure provided at the right end of the drug-filling can 20.
This is done by opening 4.

After that, the lid 20 of the injection can 20 is closed to make it hermetically sealed, and the vacuum pump 203 is operated to perform pre-exhaust, and then the air compressor 202 is operated to a predetermined pressure (10 to 15 kg / cm 2). ² G),
The state is maintained for a certain period of time, and the preservative is injected into the laminated wood. Finally, after the rear exhaust is performed, the lid body 204 is opened. The pressure inside the drug can 20 can be monitored by a pressure gauge 201.

When the lid 204 of the canister 20 is opened, the preservative inside leaks out from the opening of the canister 20. The leaking preservative is received in the pit 60 and the liquid feed pump 601 is operated. It is designed to be returned to the measuring tank 50 by operation.

Then, the injection can 20 is left open, or the lid 204 is attached again to make the inside hermetically sealed, and the vacuum pump 203 is operated to maintain a depressurized state for a certain period of time. The excess preservative is drained off. After that, the laminated wood which has been subjected to the antiseptic treatment is taken out from the drug can 20.

In the pressure injection described above, the pre-exhaust is first performed in the injection can 20 containing the laminated material, and a part of the air in the laminated material is removed, and then the pressure treatment is performed. Although the preservative is injected by the pressure treatment, the pressurized pressure treatment is performed against the reduced pressure state by the exhaust only by returning the pressure to the atmospheric pressure without performing the pressure treatment.
That is, the requirement of charging the laminated material into the pressure vessel and pressurizing the inside of the vessel of the present invention is, in addition to the pressure higher than the atmospheric pressure, once lower than the atmospheric pressure, It also includes returning the pressure to the original atmospheric pressure.

In the present invention, the above antiseptic B is used.
As 230 ℃ obtained by redistilling creosote oil
A modified creosote oil of ~ 245 ° C fraction is used.

The creosote oil is an oil of a fraction having a boiling point of 200 ° C. to 360 ° C. obtained by distilling coal tar obtained by dry distillation of coal (J
ISK2439). In addition to its main components, methylnaphthalene and dimethylnaphthalene, it also contains high molecular weight anthracene and the like, and is generally composed of many types of aromatic components. As described above, the creosote oil is a mixture of the various components as described above, and the composition is not strictly set.

By the way, such creosote oil is
It has long been known that there is an antiseptic effect for wood, and as a preservative, it is produced as a by-product at a very low cost in the coal industry represented by coke production and city gas production. It has been used a lot.

However, such creosote oil is a mixture of various aromatic components as described above, emits a very strong aromatic odor, and has a brownish black color tone. When such a creosote oil is applied to the preservative treatment of wood, there are problems that the appearance of the wood is not beautiful and that a strange odor causes people to feel uncomfortable. For this reason, although the antiseptic effect is excellent, the creosote oil has hitherto been applied only to wood used in places such as railroad ties that do not come into much contact with people.

However, since the excellent antiseptic effect of such creosote oil is hard to be thrown away and is oily, the wood to be treated is a laminated wood in which a plurality of lamina are laminated with an adhesive. In this case, even if it is immersed in creosote oil, it has an excellent property that cracking or peeling does not occur.

Therefore, the present inventor has conducted diligent investigations and studies on the application of the creosote oil to laminated wood without losing the excellent properties of the creosote oil as a preservative, and as a result, it has been found that Therefore, they have found that the offensive odor is reduced and the excellent antiseptic effect is not lost, and they have reached the present invention.

Such a modified creosote oil retains the excellent antiseptic effect of the conventional creosote oil, has a thin and almost transparent color, and has an extremely small offensive odor. It has fast-drying properties and has excellent permeability to wood. In addition, since it does not contain a carcinogenic polycyclic aromatic compound such as 1,2-benzopyrene, there is no problem in health.

The wood preservative treatment method of the present invention comprises:
For water-soluble preservatives, it is targeted at laminated wood that cannot be subjected to preservative treatment by pressure injection method.The above oil-based modified creosote is applied to this laminated wood, and the inside of the laminated wood is subjected to pressure injection method. Since the modified creosote oil is impregnated up to this point, the modified creosote oil can be satisfactorily injected without causing cracking or peeling of the laminated wood.

Further, the obtained laminated wood which has been subjected to antiseptic treatment,
The modified creosote oil is evenly impregnated to the inside,
In addition to the excellent antiseptic effect, the dimensional stability is also excellent, and in combination with the fact that the modified creosote oil is very inexpensive compared to other oil-soluble preservatives, It can greatly contribute to the increase in the service life of the laminated wood, which is expected to increase in demand.

(Test Example) In order to confirm the effect of the antiseptic treatment method of the present invention, the antiseptic agent (modified creosote oil) of the present invention and the conventional antiseptic agent used as a comparative example were assembled. Deformation state comparison test (first test), sensory comparison test for odor of antiseptic wood (second test),
A comparative test on the dimensional stability of the preservative-treated wood (third test) and a comparative test on the preservative efficacy (fourth test) were carried out.

As the preservative according to the present invention, the first modified creosote of the 200 ° C. to 250 ° C. fraction obtained by distilling creosote and the second modified creosote of the same 250 ° C. to 300 ° C. fraction are obtained. Using creosote, as a preservative of Comparative Example, a conventional ordinary creosote oil, and a water-soluble preservative (CCA) containing chromium, copper and arsenic as active ingredients,
A preservative (ACQ) containing ammonia, copper and a quaternary ammonium salt as active ingredients is used. The contents of the comparative test and the test results will be described below.

(First test) Comparative test of deformation state of laminated wood, etc. (1) Test using laminated wood of bay pine as a test piece Lamina made of bay pine having a size of 10 cm × 3.1 cm × 30 cm per sheet 6 were laminated to prepare a large number of test pieces of laminated wood having dimensions of 10 cm × 19 cm × 30 cm as shown in FIG.

For these test pieces, FIG.
The preservative according to the present invention (modified creosote oil) was subjected to pressure injection by the pressure injection method described above, and as a comparative example, the conventional preservative was injected under pressure. Then, the deformed state of each test piece after the treatment was examined. The test results are as shown in Table 1.

[0048]

[Table 1]

As can be seen from Table 1, in the case of the oil-based preservative, the dimensional increase rate of the water-soluble preservative is 1.12 to 2.42.
It was confirmed that it was extremely small as compared with very large%, and that no deformation occurred. In addition, among the oil-based preservatives, the injection amount of the modified creosote oil according to the present invention is 1
And 57~168kg / m ^3, despite the often 50% than 97 kg / m ³ of the conventional ordinary creosote oil, the dimensions increase from 0 to 0.03% and 0.08% of the conventional ones
It is shown that the preservative according to the present invention is excellent.

(2) Test Using Southern Pine Plate Material as Test Piece As a test piece, instead of the laminated wood of Bay pine,
Using a Southern pine plate material having dimensions of 8.9 cm × 3.8 cm × 25 cm, the same test as in (1) above was performed. The test results are shown in Table 2.

[0051]

[Table 2]

As can be seen from Table 2, with the water-soluble preservative, the dimensional increase rate in the width direction is 3.15 to 3.79%, and the dimensional increase rate in the thickness direction is 4.12 to 4.78%. It was confirmed that the oil-based antiseptic was extremely small, including the comparative example, while it was very large.

Among the oiliness, in the case of the conventional creosote oil, the dimensional increase rates in the width direction and the thickness direction are 0.03% and 0.17%, respectively.
In the case of the modified creosote oil of the present invention, no increase in size was observed in both the width direction and the thickness direction, which shows that the preservative according to the present invention is excellent.

(Second test) Sensory comparison test of odor of preservative-treated wood Although creosote oil has been used as an excellent preservative for a long time, it is black in color, has a strong odor, and is injected into wood. After that, it leached out to the surface of the wood and became sticky, making it difficult to handle, so it was conventionally applied only to railroad rail sleepers. On the other hand, the modified creosote oil according to the present invention is remarkably improved in odor, color and drying property. The second test is a test to confirm this.

A test piece of wood having a predetermined size was subjected to the same pressure injection treatment as in the first test using the modified creosote oil according to the present invention. Further, as a comparative example, a test piece was subjected to pressure injection treatment using a conventional creosote oil. And the odor of the test piece after pressure injection,
A sensory test of appearance color and dryness (rapidity from the wet state to the dry state of the surface of the test piece) was performed. The test results are shown in Table 3.

[0056]

[Table 3]

As can be seen from Table 3, when the conventional creosote oil was used, an irritating odor was emitted from the test piece, the appearance of the test piece was black and it was dirty, and the dryness of the test piece was poor. It is defective and the sticky surface does not disappear for a considerable period of time.

On the other hand, in the case of the modified creosote oil of the present invention, almost no pungent odor was generated, the color was transparent and the drying property was good. From this, it is understood that the preservative according to the present invention is excellent.

(Third test) Comparative test on dimensional stability of antiseptic wood Wood swells when it absorbs water and contracts when it is dried. Wood with a higher degree of swelling and shrinkage is more likely to cause dry cracking or deformation, but as a measure of the performance of the treatment that suppresses the dimensional change of such wood, anti-swelling ability (Anti Swelling Ef
ficiency), or anti-shrinkage (Anti Shrink Efficienc
y) is used, and these are all abbreviated as ASE. ASE is calculated by the following formula.

ASE (%) = {(Vc−Vt) / Vc} × 100 where Vc: volume expansion coefficient (or volume contraction rate) of untreated material Vt: volume expansion coefficient (or volume contraction rate) of antiseptic treatment material ) Since oil-based preservatives such as creosote oil repel water, absorption of water into the wood is suppressed, but water-soluble preservatives do not have such a problem and are not exposed to rain outdoors. Then, a large amount of water penetrates into the wood and swelling becomes remarkable. The degree of swelling that varies depending on the type of preservative can be evaluated by the magnitude of the ASE value. This AS
The higher the value of E, the greater the swelling inhibiting effect of the preservative.

Therefore, the Vc value of the untreated test piece was measured, and the Vt of the test piece preserved with the modified creosote oil according to the present invention was measured, and the ASE value was calculated by the above equation. Also, as a comparative example, a conventional ordinary creosote oil and two types of water-soluble preservatives are used,
The same measurement as above was performed to calculate each ASE value. Table 4 shows the test results. Further, a graph of Table 4 is shown in FIG. In FIG. 3, A is the first modified creosote according to the present invention, B is the second modified creosote, C is a conventional ordinary creosote, D is the water-soluble CCA, and E is the same as above. ACQ is shown respectively.

[0062]

[Table 4]

As can be seen from Table 4 and FIG. 3, the oil-based preservative has a remarkably large ASE value as compared with the water-soluble preservative, and the absorption of water is suppressed even when wet with water, so that ordinary wood can be used. It can be seen that dimensional changes are less likely to occur. Among the oil-based preservatives, the modified creosote oil according to the present invention has an ASE value of 30 to 34%, which is about 30%, which is similar to that of the conventional creosote oil. It can be seen that the antiseptic according to (1) is excellent.

(Fourth test) Comparative test of antiseptic effect (1) Comparative test of antiseptic effect based on JIS standard Based on JISA9201 (performance standard and test method of wood preservative), the modified creosote oil according to the present invention and A comparative test of antiseptic efficacy was carried out on the antiseptics of Comparative Examples.
The test results are shown in Table 5.

[0065]

[Table 5]

Preservative efficacy of preservatives (weight reduction rate in Table 5)
The performance standard of is less than 3%, but as can be seen from Table 5,
All modified creosotes according to the present invention meet the above performance criteria.

(2) Field Pile Test A thin pile (3 cm × 3 cm × 60 cm) preservatively treated with the modified creosote oil according to the present invention and the preservative of the comparative example was embedded in the test soil for the lower half for 2 years. After leaving it to stand, the top, ground and bottom of the pile were visually observed to determine the degree of decay. Table 6 shows the determination results.

[0068]

[Table 6]

As can be seen from Table 6, the untreated piles were badly decayed and most of them were damaged. However, those treated with the modified creosote oil according to the present invention were treated with other preservatives. It was confirmed to be comparable to the treated product of the agent, and it was confirmed that the agent has a sufficient durability effect as a preservative.

[0070]

As described in detail above, the method of preserving wood according to the present invention is to use creosote oil as the preservative used in the preservative pressure injection step of immersing the laminated lumber in the preservative and pressurizing it. The modified creosote oil obtained by redistillation is used. Since such a modified creosote oil is a so-called oil-based preservative, even if the laminated lumber is immersed in the modified creosote oil in the preservative pressure injection step, the laminated lumber constitutes the laminated lumber. Each lamina present does not swell, so that the laminated material is not cracked or peeled off, and it is possible to perform the preservative treatment by the pressure injection method in a state without dimensional deviation.

As the modified creosote oil, 200 ° C. to 300 ° C. obtained by redistilling creosote oil
If you apply the fraction of the above, the modified creosote oil of such a fraction is almost transparent color instead of black that gives a dirty appearance, has less offensive odor, and is similar to benzopyrene. It does not contain any carcinogenic substances and does not cause discomfort to the laminated wood impregnated with such modified creosote oil, and is applied to structures such as buildings that are in contact with many people. It is possible and convenient.

Further, the modified creosote oil of the above fraction has the same antiseptic effect as that of the creosote oil, even though the coloring component and the offensive odor generating component are removed from the creosote oil, and the laminated wood Since it is uniformly impregnated by the pressure injection operation, the antiseptic effect can be maintained for a long time and the service life of the structure can be extended.

In addition, since the modified creosote oil as described above is significantly cheaper than other types of oil-soluble preservatives, it is possible to significantly reduce the material cost for preservative treatment. It is convenient because it is possible to put laminated wood that has been subjected to antiseptic treatment at a low cost on the market.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an example of an antiseptic treatment apparatus to which a wood antiseptic treatment method according to the present invention is applied.

FIG. 2 is a perspective view showing a test piece of laminated wood.

FIG. 3 is a graph showing ASE values of Examples and Comparative Examples.

[Explanation of symbols]

 10 Antiseptic Treatment Equipment 20 Injection Can 201 Pressure Gauge 202 Air Compressor 203 Vacuum Pump 204 Lid 30 Storage Tank 301 Liquid Delivery Pump 40 Dissolution Tank 401 Liquid Delivery Pump 50 Metering Tank 501 Pressure Pump 60 Pit 601 Liquid Delivery Pump

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Yoshikatsu Matsumoto 1-2-158 Hirabayashi Kita, Suminoe-ku, Osaka City Koshii Lumber Industry Co., Ltd. (72) Inventor Kiyosaku Kashiwazaki 1-2-2 Hirabayashi Kita, Suminoe-ku, Osaka No. 158 Within Koshii Lumber Industry Co., Ltd.

Claims (2)

[Claims] 1. A preservative treatment method for wood, wherein wood is loaded into a pressure vessel filled with a preservative and the pressure vessel is pressurized to forcibly impregnate the wood with the preservative. A modified creosote oil obtained by further redistilling the creosote oil obtained by fractionating coal tar as the above preservative is used by using an laminated material in which a plurality of sawing boards are laminated via an adhesive. A method for preserving wood, which is characterized by being used. 2. The method for preservative treatment of wood according to claim 1, wherein the modified creosote oil is a fraction of the creosote oil at 200 ° C. to 300 ° C.