JP3433423B2 - Insect repellent plywood. - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insect-proof / moisture-proof plywood used as a base material for interior / exterior materials, furniture, tables, etc. used in houses and other constructions.

[0002]

2. Description of the Related Art Conventionally, warpage due to moisture and water, which are major drawbacks of wood-based materials, and feeding damage due to insect pests such as flat beetles in addition to twisting have been problems. Therefore, as an insect repellent treatment to be applied to plywood and the like, chlordane, organic chlorine compounds such as heptachlor, boric acid, chloronaphthalene-based agents, organic tin-based compounds such as tributyltin oxide, chloronicotinyl-based insect repellents such as imidacloprid Have been used. As a method of insect repellent treatment, the chemicals are soaked in a chemical solution, applied with a chemical solution, or mixed with an adhesive agent when manufacturing plywood. For example, JP-A-5
Japanese Patent Laid-Open No. 5-28844 describes a method of bonding a veneer for plywood using an insect-repellent adhesive containing a nitrogen-containing base and boric acid.

On the other hand, as a countermeasure against warp and twist of plywood and other wood-based materials, moisture-proof treatment has conventionally been applied to wood-based materials such as plywood.
Various have been implemented. For example, JP-A-9-3145
No. 23, describes a medium specific gravity fiber board substrate having OPP films attached to both surfaces thereof, and JP-A-7-
Japanese Patent No. 251407 discloses that a back surface of a wood base material is adhered with a moisture-proof paper having paper on both sides and a middle layer made of a moisture-proof sheet.

[0004]

However, the above
Among the insect repellent treatments for plywood, the method of immersing or applying wood veneer in an insect repellent solution not only makes the treatment time consuming and expensive, but also its workability was not good at all. . Further, the method of mixing the insect repellent into the adhesive has a low treatment cost and relatively good workability, but if the water content of the wood veneer is not about 12% or more, the agent will be deep inside the veneer inner layer. Not penetrated, about 22
When the content exceeds%, the drug penetrates well, but due to the high water content, poor adhesion and puncture phenomenon during hot pressing were likely to occur. Therefore, it is said that the optimum moisture content of the wood veneer is about 12% to 22%. However, when the moisture content is about 14% or more, the plywood itself is warped and twisted easily after the later construction. Therefore, the moisture content of wood veneer is approximately 12% to 1
Although it may be finely controlled to 4%, it is very difficult to control the water content of the wood material in such a fine manner.

As for the warp twist after the construction, even if the warp twist is sufficiently dried so that the water content is 12% or less, the warp twist becomes a big problem at a later date when the work is performed in a place where the humidity environment is bad. . Therefore, there has been a demand for an insect-proof and moisture-proof plywood which has a good workability of insect-proof treatment and has a reliable insect-repellent effect, and which is less likely to be warped and twisted even if it is constructed in a place where the humidity environment is bad in the later construction. Moreover, there has been a demand for an insect-proof and moisture-proof plywood for which the water content of the veneer is relatively wide. That is, it can be manufactured by a simple method with relatively good workability, and can be manufactured even in a relatively wide range of water content, it has a high insect repellent effect and does not cause adhesion failure, and it can be installed in a place where the humidity environment is bad in the later construction. There has been a demand for insect-proof and moisture-proof plywood that is resistant to warpage and twisting after construction.

[0006]

As a result of intensive studies to solve the above problems, the invention described below has been reached. That is, according to the invention of claim 1, in a plate-shaped body formed by sequentially laminating and bonding an odd number of wood veneers in the thickness direction while making the fiber directions orthogonal to each other, the water content of the wood veneers is 12 to 22%. The above-mentioned problems are solved by an insect-proof and moisture-proof plywood which is characterized in that it is prepared to have a relatively high water content, and the insect-proof and moisture-proof paper is interposed between the wood veneers.

According to a second aspect of the present invention, the insect-proof and moisture-proof paper has a thickness of 2 between the outer two layers of the insect-proof treated paper material.
The above problem is solved by the insect-proof and moisture-proof plywood according to claim 1, which is a polysand sheet having a three-layer structure in which a polyethylene film of 0 to 40 microns is interposed.

The meaning of the high water content mentioned here is as follows. That is, since the workability is poor in the method of dipping or coating in the insect repellent solution in the insect repellent treatment of the single plate, in the insect repellent treatment excellent in workability other than the dipping method and the coating method,
In addition, in order to sufficiently exhibit the insect repellent effect, that is, the wood veneer used in the present invention has a relatively high water content in order to sufficiently penetrate the effect of the insect repellent deeply in the thickness direction of the veneer. It is necessary to adjust the rate. For example, about 12% to 22% is required, but if it is this range, there is no fear of puncture during hot pressing at the time of manufacturing plywood and adhesion failure. Wetting is relatively easy.

If the water content of the wood veneer is not more than about 12%, the insect repellent does not penetrate deep into the inner layer of the veneer, and if it is about 22% or more, adhesion failure or puncture phenomenon at the time of hot pressing occurs. Therefore, the moisture content of wood veneer is about 12
% To 22% is optimum. However, when the water content is about 14% or more, the plywood itself tends to be warped and twisted after the later construction. Therefore, the water content of the wood veneer is carefully controlled to approximately 12% to 14%.
However, it is very difficult to control the water content of the wood material in such a fine manner.

Therefore, it is important to make the insect-proof plywood that does not warp even after the veneer has a water content of 14% or more. By interposing the insect-proof and moisture-proof paper between the boards, the insect-repellent chemical penetrates deeply into the veneer because it is a relatively high water content veneer, the insect-proof effect is high, and adhesion failure does not occur, and
Since there is a moisture-proof paper between the veneers, it is possible to make insect-proof and moisture-proof plywood that is resistant to warpage and twisting after construction. That is, it is important to adjust the water content of the wood veneer used in the present invention to a relatively high water content, preferably about 12% to 22%. Within this range, plywood production There is no fear of puncture or adhesion failure at the time of hot pressing, and humidity control of a single plate can be performed relatively easily in this wide range.

As the insect-proof and moisture-proof paper in the present invention, any one can be used as long as it is a moisture-proof processed by adding a pesticide to a paper-based material, and above all, a synthetic resin film is used for the insect-proof paper. Laminated ones are easy to use. Among them, a moisture-proof sheet having a three-layer structure in which the outer two layers are paper-like materials and the central core layer is a synthetic resin film is good, but not limited to this. 4 even with a two-layer structure
It may have a multi-layer structure of more than one layer. The three-layered polysand sheet, in which the two outer layers are made of a paper material and the center layer is a polyethylene film having a thickness of 20 to 40 microns, is cost-effective and moisture-proof, and has good adhesiveness to the wood veneer. It is also excellent and stable in. It is sufficient to use a paper-like material of the outer two layers of this polysand sheet that has been subjected to insect repellent treatment.

Since the outer two layers are made of a paper material, an ordinary wood adhesive can be used in the step of adhering to a wood veneer, so that the workability is excellent and a relatively inexpensive adhesive can be used. The subsequent adhesion performance is stable, and there is no risk of peeling or adhesion failure. It is preferable to use, as the moisture-proof paper, one obtained by impregnating the two outer paper-material layers with the solution of the insect repellent and then drying it. However, the present invention is not limited to this, and a method other than the impregnation is used for coating or coating. According to the above, it may be other than that.

The insect repellent may be oil-soluble, but if a water-soluble insect repellent is selected, the workability is relatively improved. Also, 3
The layered polysandsheet is often made by laminating a polyethylene resin film between two layers of paper material in a sandwich structure by an adhesive method or a heat fusion method. Then, an insect-proof / moisture-proof paper is interposed between the wood veneers and is pressed and bonded by a hot press or a cold press to obtain the insect-proof / moisture-proof plywood of the present invention.

[0014]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of the insect-proof and moisture-proof plywood of the present invention. FIG. 2 is a schematic sectional view showing an insect-proof and moisture-proof paper using a poly-sand sheet having a three-layer structure. 1 is the plywood of the present invention,
2 is a wood veneer, 3 is a insect-proof and moisture-proof paper, 4 is a paper material, and 5 is a polyethylene film.

In FIG. 1, the wood veneer (2) may be a normal lauan veneer, a softwood veneer such as Radia Tapine, Southern Pine, etc., or a hardwood veneer such as beech or timber, or other materials. It may be. Of these, the present invention is most effective when used for the Lauan veneer, which is the most seriously damaged by the flat beetle. These wood veneers (2) are prepared in advance to have a high water content. The method of adjusting the water content is that the wood veneer can be relatively easily and accurately adjusted by storing the wood veneer for a long time in an environment room with a predetermined temperature and humidity. If the time required for humidity control is at least one month or more, stable and accurate humidity control can be achieved. Temperature and humidity to achieve the target equilibrium moisture content. A long-term curing in an environment room to regulate the moisture content to the target moisture content.

As described above, the high water content is 12% to
22% is the best. That is, the wood veneer (2) used in the present invention has its water content adjusted to a relatively high water content. For example, if it is about 12% to 22%, there is no danger of flatness or adhesion failure during hot pressing during plywood production,
In addition, the humidity of a single plate can be relatively easily adjusted within this wide range.

Further, if the water content is high, the insect repellent agent of the insect-proof and moisture-proof paper (3) interposed between the wood veneer (2) and the wood veneer (2) is inside the wood veneer (2). As it penetrates deep inside, it can exert a high insect repellent effect. That is, if the water content of the wood veneer (2) is lower than 12%, the insect repellent will not penetrate deep into the wood veneer (2),
Therefore, the insect repellent performance is inferior. If the water content of the wood veneer (2) exceeds 22%, defective adhesion and puncture phenomenon will occur during the production of plywood.

As the insect-proof / moisture-proof paper (3), any paper can be used as long as it is a paper-like material (4) to which an insect-repellent chemical is applied and the insect-proof paper is moisture-proof processed.
As the insect-proof paper, a paper-like material (4) impregnated with an insect-repellent chemical and applied is preferable.

As the paper material (4) constituting the insect-proof and moisture-proof paper (3), kraft paper, thin paper, Japanese paper, non-woven fabric,
Other paper materials can be used, but other materials may be used. The basis weight of the paper-based material (4) is about 23 to 30 g / m ^{2 in} terms of cost and manufacturing workability, and there is no fear of separation between the sheets due to the paper-based material becoming too thick. Suitable. Further, it is optimal from the viewpoint that there is no fear that the adhesive strength to the wood veneer will be deteriorated due to being too thin. However, it is not limited to this. It is preferable that the paper material (4) and the synthetic resin film have a two-layer structure or a multi-layer structure of three or more layers by an adhesion method or a heat fusion method.

As the insect repellent used for the insect repellent paper, borax, boric acid, soda fluoride and other insect repellents can be used. The permeation amount into the paper-based material may be 0.2% or more in the case of borax or boric acid with respect to the total dry weight of the paper-based material. Further, in the case of soda fluoride, it may be 0.1% or more. The paper material may be dipped in the treatment chemical with a concentration of about 1 to 2%, or may be applied by brush, roll coater or spray. After the chemical treatment, the desired insect-proof paper is obtained by drying.

As the moisture-proof treatment, insect-proof paper coated with a synthetic resin such as urethane, polyester or polyethylene may be used, or insect-proof paper treated with paraffin or wax for water repellency may be used. Also, a sheet of insect-proof paper laminated with a synthetic resin film may be used. Among these, insect-proof paper laminated with a synthetic resin film is relatively inexpensive and easily available. It may have a two-layer structure, a three-layer structure, or a structure having four or more layers.

Among them, as shown in FIG. 2, the outer two layers are made of paper material (4) and the middle layer is made of polyethylene resin film. It is the best to think from. Since the outer two layers are paper material (4), the adhesiveness with the wood veneer (2) is also good,
Therefore, polysandsheet is the best.

However, the present invention is not limited to this.
The layer structure may be a two-layer structure, a three-layer structure, or a multi-layer structure of four or more layers. In particular, it is cost effective to use a polyethylene film having a thickness of 20 to 40 microns for the core layer.
It is optimal considering moisture resistance, adhesion to wood veneer, availability, and ease of use. If it is thinner than 20 microns, the moisture-proof effect will be poor, and if it is thicker than 40 microns, it will be costly and economically disadvantageous. Other than polyethylene film, polyolefin resin film, vinyl chloride resin film, polyester resin film, O
A PP resin film or the like can be used.

[0024]

Example 1 Five Lauan veneers having a predetermined thickness were prepared, and the water content was adjusted in advance to a range of 22 ± 1%. The adjustment method is temperature and humidity conditions such that the equilibrium water content of the Lauan veneer is 22%.
%, The humidity was adjusted to a range of 22 ± 1% by controlling the humidity in an environmental chamber for about 1 month. The lauan veneer has a thickness of 1.2 mm for the front and back surfaces and 3.5 mm for the second and fourth layers.
The thing of 2.6 mm was prepared for a core.
As the insect-proof and moisture-proof paper (3), the outer two layers are 23 g / m
^{In 2} , a polysand sheet having a three-layer structure, which is made of thin paper that has been insect-proofed in advance and has a thickness of 20 μm as a core layer, is used.

As the insect repellent, a 2% aqueous solution of boric acid was used. A thin paper having ^two outer layers of 23 g / m ² was dipped in the aqueous boric acid solution for 30 minutes, then dried at 20 ° C. for 24 hours and further dried at 40 ° C. for 30 minutes to prepare insect repellent paper. Next, using the above-mentioned 20-micron-thick polyethylene film in the middle, and using insect-proof thin paper on the outer two layers, a temperature of 11
Heat fusion was performed at 0 ° C. for about 60 seconds to produce a polysand sheet with a three-layer structure and an insect repellent finish. There was no problem with the polyethylene film at this temperature time.

Next, the five layers of Lauan veneer having the above-mentioned high water content are made to have their fiber directions orthogonal to each other, and the polysand seams with insect repellent treatment having the above three layers are arranged between them.
Example 1 in which the adhesives are sandwiched, the adhesive is applied in accordance with the predetermined lamination order of the veneer thickness, the sheets are sequentially stacked, and hot pressed.
A 5 ply 12 mm thick insect-proof and moisture-proof plywood was prepared. As the adhesive, urea resin adhesive is used, and the temperature is 90
It was produced under the conditions of ℃, pressing pressure of 7 kg / cm ² and pressing time of 10 minutes. Under such temperature and time conditions, the polyethylene film was not affected.

Example 2 A sample of Example 2 was prepared in exactly the same manner as in Example 1 except that the water content of the Lauan veneer was adjusted to 12 ± 1%.

[Comparative Example 1] A sample of Comparative Example 1 was prepared in the same manner as in Example 1, except that the water content of the Lauan veneer was set to 8%.

[Comparative Example 2] In Example 1, the thickness of the polyethylene film of the middle layer of polysandsheet was 15
A sample of Comparative Example 2 was prepared in exactly the same manner except that the sample size was set to micron.

[Insect repellent / moisture proof test] The insect repellent / moisture proof performances of the samples of Examples 1 and 2 and Comparative Examples 1 and 2 were compared. The insect repellent performance was compared by the length of feeding damage by the flat beetle. The moisture-proof performance was compared by the amount of warpage in a humid environment. The results are shown in Table 1 below.

[0031]

[Table 1] Table 1: Insect repellent performance test results Unit: Both insect repellent performance and moisture repellent performance mm

[Test Method] 1) Insect repellent test A 10 cm square test piece was cut out from the samples of Examples 1 and 2 and Comparative Example 1 and tested. Three cubic boxes each having a length, width, and height of about 30 cm were prepared, and one piece of each test sample and 10 adults of the flat beetle were released into the box. The test was started from the end of May, which is the spawning period, and the test was performed for about 3 months while observing the situation. The test box was stored in an environmental test room where the temperature was 25 ° C. and the relative humidity was adjusted to 80%. One month after the midway and three months after the last, the presence or absence of feeding damage from the sample mouth and the total length of feeding damage were measured with a caliper. 2) Moisture-proof test (warp test) Using the insect-proof / moisture-proof plywood of Examples 1 and 2 and Comparative Example 2 as a base material, a 0.3 mm-thick oak veneer is attached to the surface with a urea adhesive, and the surface is coated with urethane resin. Give it a thickness of 12 mm,
A full-scale floorboard sample having a width of 303 mm and a length of 1818 mm was prepared. Each floor board was exposed for 30 consecutive days in a hot and humid environment with a temperature of 30 ° C. and a relative humidity of 95%. The amount of warpage in the lengthwise direction was measured with a scale and a caliper one week later, two weeks later, and one month after the final one.

[Discussion of test results] 1) Insect repellent test The samples of Example 1 in which the water content of the Lauan veneer was adjusted to 22 ± 1% and the sample of Example 2 in which the water content was adjusted to 12 ± 1% were taken one month later. The damage length is 0.6 mm and 0.9 mm, and the damage length after 3 months is only 0.7 mm and 1.3 mm,
It can be seen that there was a great insect repellent effect. On the other hand, in Comparative Example 1 in which the water content of the Lauan veneer was 8%,
Since insect repellents do not penetrate inside the veneer, 1
The length of feeding damage after 3.5 months was 3.5 mm, and that after 3 months was 12.8 mm. 2) Moisture-proof performance (warp test) The warp amount of Example 1 in which the thickness of the polyethylene film used for the core layer of the polysandsheet was 20 μm, the water content of the veneer was 22 ± 1%, which was a high water content. Nevertheless, it was 3.5 mm after one month and was extremely resistant to moisture. Since the water content of the single plate in Example 2 was 12 ± 1%,
The amount of warpage after one month was even lower, being 2.0 mm. On the other hand, in Comparative Example 2, since the polyethylene film was as thin as 15 microns, the warpage amount 4.8 m after 2 weeks.
After 1 month, the amount of warpage was 9.3 mm, which was slightly large.

[0034]

INDUSTRIAL APPLICABILITY The insect-proof and moisture-proof plywood of the present invention does not have a single sheet impregnated with an insect-repellent chemical as an insect-repellent treatment. By controlling the moisture content to a relatively high moisture content in advance, the insect repellent penetrates deep inside the veneer inner layer, and therefore,
Its insect-proof effect is high, and since moisture-proof paper that also serves as insect-proof paper is interposed between the veneer layers, even if it is a plywood with a high water content veneer adhered, moisture and external It is possible to obtain plywood having stable quality and insect-proof and moisture-proof performance without fear of warpage twist due to water.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of an insect-proof and moisture-proof plywood of the present invention.

FIG. 2 is a schematic cross-sectional view showing an insect-proof and moisture-proof paper using a polysand sheet having a three-layer structure.

[Explanation of symbols]

1 Plywood of the present invention 2 wood veneer 3 insect-proof and moisture-proof paper 4 Paper materials 5 Polyethylene film

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-11-240001 (JP, A) JP-A-50-4135 (JP, A) JP-A-55-28844 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) B27D 1/00-5/00

Claims (2)

(57) [Claims] 1. A plate-shaped body obtained by sequentially laminating and bonding an odd number of wood veneers in the thickness direction while making the fiber directions orthogonal to each other, wherein the wood veneers have a high water content of about 12 to 22%. The insect-proof and moisture-proof plywood, characterized in that the insect-proof and moisture-proof paper is interposed between the wood veneers. 2. The insect-proof and moisture-proof paper is a three-layered polysand sheet in which a polyethylene film having a thickness of 20 to 40 μm is interposed between two outermost layers of insect-proof paper material. The insect-proof and moisture-proof plywood according to claim 1.