JP2000141324A - Wooden fiber laminated board, its manufacture and gage panel of pachinko stand - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wooden fiber laminated board, which is excellent in nailing properties and a nail holding force, its manufacturing method and the gage plate of a pachinko stand. SOLUTION: This wooden fiber laminated board is integrally formed with a binder under the condition that the resultant density distribution is 0.52 to 1.00 g/cm3 and a layer having a density of 0.80 g/cm3 or more is not present or present in a part ranging from the surface of the board to its thickness of 2 mm. In this case, the major portion of wooden fibers employed in the wooden fiber laminated board is wooden fibers, the total density of which is 0.65 to 0.85 g/cm3, the length of which is 0.1 to 10 mm and the diameter of which is 2 to 300 μm. A preferable binder is polyether-based polyurethane. A backsheet-clad wooden fiber laminated board is produced by laminating a backsheet on at least one side of the board into an integrated body. The board is useful for the gage panel of a pachinko stand.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a wood fiber integrated board,
The present invention relates to a manufacturing method and a gauge board for a pachinko machine.

[0002]

2. Description of the Related Art Wood fiber laminated boards made of wood fibers are used for various purposes. One of the uses is a gauge board of a pachinko machine. In a wood fiber integrated board such as an ordinary MDF (medium density wood fiber integrated board), a layer having a high density, a so-called bedrock layer, is easily formed on the surface of the press-formed product due to the characteristics of the press-forming method. On the other hand, as a panel performance required for a gauge board of a pachinko machine or the like, it is required that nails are easy to strike and that the nails have a holding force. However, since the bedrock layer formed on the surface is hard, there are adverse effects such as not being able to strike the nail and bending the nail when the nail is struck. If you lower the overall density of the wood fiber accumulation board so that the nail can be hit, there is a problem that the overall strength of the wood fiber accumulation board and the holding power of the nail also decrease, and ordinary wood fiber accumulation boards are used. Because of this, the gauges of pachinko machines relied exclusively on plywood using precious wood resources such as Rawan merantee.

[0003] In Japanese Patent Application Laid-Open No. 10-128711, the sizes of acetylated wood fibers and / or the wood powder obtained by pulverizing the acetylated wood fibers are selected and made uniform. A wood fiber integrated board obtained by applying a binder to wood fiber and / or wood powder and molding and integrating the same is disclosed. In the case of the wood fiber integrated board, a step required for acetylation treatment is required, There was a problem that the manufacturing cost of the fiber integrated board was high.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides nailing properties,
It is an object of the present invention to provide a wood fiber integrated board having excellent nail holding power, reduced warpage and twist caused by a change in humidity, and capable of being manufactured at low cost, a method of manufacturing the same, and a gauge board for a pachinko machine.

[0005]

According to the present invention, there is provided a wood fiber integrated board in which wood fibers are integrated by molding with a binder, and have a density distribution of 0.52 g / cm ^{3 to} 1.00 g / cm ^3.
In which no layer having a density of 0.80 g / cm ³ or more is present, or a wood fiber integrated board whose surface has a thickness of less than 2 mm. In the wooden-fiber stacking plate, it is preferable that the entire density thereof is ^{0.65g / cm 3 ~0.85g / cm 3} , is 0.1mm or more in length, 10.0
mm or less, it is preferable that wood fibers having a diameter of 2 μm to 300 μm occupy most of the wood fibers,
Preferably, the binder is a polyether-based polyurethane. The backsheet-attached wood fiber accumulation board is obtained by integrating a back sheet on at least one side of the wood fiber accumulation board. In the method for producing a wood fiber integrated board according to the present invention, the wood fibers are integrated by molding with a binder, and the density distribution is 0.52 g / cm ^{3 to} 1.00 g.
/ Cm ³ , wherein there is no layer having a density of 0.80 g / cm ³ or more, or a method for producing a wood fiber integrated board having a surface portion having a thickness of less than 2 mm, wherein the wood fiber In this method, a wood fiber having a water content of 15% by weight or less is attached to a binder, the wood fiber to which the binder is attached is formed, and the wood fiber is bound by the binder. In the manufacturing method, the length is 0.1 m
m or more and 10.0 mm or less, and a diameter of 2 μm to 300 μm.
Preferably, wood fibers of size m occupy the majority of the wood fibers. The gauge board of the pachinko machine according to the present invention is the above-mentioned wood fiber accumulation board, wherein the thickness is 15 mm to 25 mm.

[0006]

FIG. 1 is a cross-sectional view showing an example of a wood fiber integrated board according to the present invention. The wood fiber integrated board is made of wood fibers obtained by integrating wood fibers 1a by molding with a binder 1b. The density distribution of the wood fiber integrated board 1, that is, the density distribution of the core layers 1d and the surface layers 1c and 1c having high density formed on both surfaces of the core layer 1d is 0.52 to 0.52.
1.00 g / cm ³ range and density 0.80 g
/ Cm ³ or more, or the density is 0.80
It is a wood fiber integrated board having a thickness of less than 2 mm as a surface layer 1c on the surface even if a layer of g / cm ³ or more is present.
The wood fiber accumulation board has a length of 0.1 to 10.0 mm.
The binder is attached to the wood fiber having a diameter of 2 to 300 μm and having a water content of 15% by weight or less, and then the wood fiber to which the binder is attached is subjected to pressure molding. Can be produced by bonding with the binder. Therefore, the wood fiber integrated board of the present invention can be easily manufactured and can be manufactured at low cost.

Wood fibers used for manufacturing a wood fiber integrated board are manufactured as follows. That is, as the wood fiber, a hardwood or coniferous wood obtained by chipping with a chipper and defibrating the obtained chip is used. For fibrillation, a method of steaming with high-pressure steam at about 150 ° C. and then fibrillating with a disc refiner is used. The wood fibers obtained by defibration can be used after being acetylated, but may be used without being acetylated. ADVANTAGE OF THE INVENTION According to this invention, even if a wood fiber is not acetylated by reducing a rock layer etc., the wood fiber accumulation board excellent in nailing property, nail holding power, etc. can be obtained. Wood fiber in total weight of wood fiber accumulation board (however, absolute dry weight)
Is about 70% by weight, preferably 85% by weight or more,
It is easy to obtain a wood fiber integrated board having excellent nailing properties and nail holding power.

In the present invention, as the wood fiber, a wood fiber having a length of 0.1 to 10 mm and a diameter (thickness) of 2 to 300 μm is mainly used. Here, occupying the majority means that the length is 0.1 to 10 mm in the total amount of wood fibers used for manufacturing the wood fiber integrated board.
Approximately 7 wooden fibers having a diameter of 2 to 300 μm
0% by weight, preferably about 85% by weight or more. If the length of the wood fiber exceeds 10 mm, it is difficult to strike a nail straight into the wood fiber accumulation board. When the length of the wood fiber is 0.1 to 10 mm, it is easy to drive a nail straight into the wood fiber accumulation board. The length and diameter of the wood fiber can be determined by microscopic observation.

Wood fibers having a water content of 15% by weight or less are used. The wood fiber having the above-mentioned water content can be obtained by selecting the drying condition of the wood fiber. When a wood fiber having a water content of more than 15% by weight is used, a density of 0.8 g / c is applied to the surface of the wood fiber integrated board.
thickness in m ³ or more is likely to be a 2mm or more layers. The water content of the wood fibers is based on Japanese Industrial Standard, JIS A5
905-1994. That is, the water content (% by weight) is (m ₁ −m ₀ ) × 100 / m ₀ . here
And m ₁ is the mass (g) of the wood fiber sample before drying,
m ₀ is the mass (g) when the wood fiber sample was put into an air dryer at 103 ° C. and became a constant weight.

Urea resins, melamine resins, phenolic resins, polyurethane resins, epoxy resins and the like and mixtures thereof can be used as binders for binding the wood fibers. The preferred binder to use is a polyurethane resin. In particular, a polyether obtained by reacting an isocyanate compound having two or more isocyanate groups in one molecule with a polyether polyol having two or more hydroxyl groups in one molecule and having many ether bonds in one molecule A system-based polyurethane resin is preferable because it gives a soft cured product. The polyether polyol preferably has a number average molecular weight of 200 to 4000. When the number average molecular weight is from 200 to 4000, it is easy to obtain a wood fiber integrated board excellent in nail driving performance and nail holding power. Examples of isocyanate compounds are crude diphenylmethane-4,4'-diisocyanate, and examples of polyether polyols are polyglycols.

The amount of the binder used is preferably 4 to 15 parts by weight in terms of solid content based on 100 parts by weight of the absolute dry weight of the wood fiber. If the amount of the binder is less than 4 parts by weight, it is difficult to make a plate, the nail holding force is weak, and the bending strength is weak. If the amount exceeds 15 parts by weight, a rock layer having a thickness of 2 mm or more tends to be formed, and it is excessive and economically disadvantageous. When a polyether-based polyurethane resin obtained by reacting an isocyanate compound with a polyether polyol is used as a binder, the polyether polyol is used in an amount of 15 to 150 parts by weight, based on 100 parts by weight of the isocyanate compound.
Preferably, it is used in a proportion of 30 to 100 parts by weight. If the weight is less than 15 parts by weight, the wood fiber integrated board 1 is too hard to drive nails. If the weight is more than 150 parts by weight, the nails are easy to drive, but the softness is too low and the nail holding power is insufficient.

When the isocyanate compound and the polyether polyol are separately applied to the wood fibers, the isocyanate compound is used in an amount of 4 to 20 parts by weight, preferably 7 to 15 parts by weight, based on 100 parts by weight of the absolute dry weight of the wood fibers. And the polyether polyol is preferably in a proportion of 3 to 15 parts by weight. In this case, after applying the isocyanate compound to the wood fiber, the polyether polyol can be applied thereon. When the isocyanate compound and the polyether polyol are mixed in advance and applied to the wood fiber, the total amount of the isocyanate compound and the polyether polyol is 4 parts by weight based on the absolute dry weight of the wood fiber of 4 parts.
It is preferable that the ratio is 15 parts by weight. In this case, the polyether polyol is 15 to 150 parts by weight, particularly 30 parts by weight, based on 100 parts by weight of the isocyanate compound.
It is preferable that the ratio is 100 parts by weight. If the proportion of the polyether polyol is less than 15 parts by weight, the wood fiber integrated board becomes too hard and the nailing property is not good. When the compounding ratio of the polyether polyol is more than 150 parts by weight, the wood fiber integrated board is soft and the nailing property is good, but the nail holding power is insufficient.

The length is 0.1 to 10 mm and the diameter is 2 to 300
A mixture of wood fibers having a size of μm and having a water content of 15% by weight or less, a binder, etc., and attaching the binder to the surface of the wood fibers forms a wood fiber integrated board. Wood fiber material is prepared. The mixing of the wood fiber and the binder may be performed by a spray method. For example, a method is preferable in which a wood fiber whose size and moisture content are adjusted is put into a rotating drum rotating at a low speed, and a binder is spray-coated on the wood fiber when the wood fiber falls naturally in the rotating drum. . When the binder is a polyether-based polyurethane resin,
An isocyanate compound and a polyether polyol are dissolved in a solvent in advance to form a mixed solution, and the mixed solution may be applied to wood fibers by a spray method, or a mixture in which the isocyanate compound and the polyether polyol are separately dissolved in a solvent. The liquid may be separately applied to the wood fibers by a spray method. When using a spray device having good uniform dispersion, dilution with a solvent is unnecessary.

By hot-pressing the mat-like material, a wood fiber integrated board in which wood fibers are bonded by a binder can be obtained. By this hot pressing, the binder in the mat-like material reacts and hardens, and the wood fibers are bound by the hardened material of the binder. The hot pressing temperature is about 150-230 ° C., depending on the type of binder. If the wood fiber has a water content of 15% by weight or less and the thickness of the wood fiber integrated board obtained by hot pressing is about 10 to 30 mm, a layer having a density of 0.80 g / cm ³ or more is formed. It is absent and has an internal density of more than 2 mm
2 g / cm ³ or more at 0.8 g / cm ³ less than the a wood fiber stacking plate, or density also of the layer thickness present on the surface portion is 0.80 g / cm ³ or more layers becomes less than 2mm It is easy to obtain a wood fiber integrated board in which the density of the portion inside the surface portion (that is, the core layer 1d) is about 0.52 g / cm ³ or more and less than 0.8 g / cm ³ . Such a wood fiber accumulation board is excellent in nailing property and nail holding power.

On one side of the wood fiber accumulating plate, for example, a thickness of 0.1 mm
When a cell decorative sheet (not shown) having a thickness of 3 to 0.7 mm is applied, the front and back surfaces are asymmetric, and the cell decorative sheet-attached wood fiber integrated board is likely to be warped and twisted due to a change in humidity or the like. This warping and twisting can be prevented by integrating the back sheet on at least one side, preferably both sides, of the layer in which the wood fibers are bound by the binder.
The backsheet is at least integrated with the surface opposite to the surface of the wood fiber assembly board to which the cell decorative sheet is attached.
An adhesive can be applied to the backsheet in advance, and the backsheet can be bonded to the preformed wood fiber accumulation board to integrate the backsheet into the wood fiber accumulation board.
It is preferable that the back sheet is integrated with the layer of the wood fiber bonded by the binder by superimposing the back sheet on the wood fiber to which the binder is attached and performing hot-press molding. The backsheet-attached wood fiber integrated board 3 shown in FIG.
This is an example in which back sheets 2 and 2 are integrated by lamination on both surfaces of the surface layers 1c and 1c of the wood fiber integrated board 1. In addition,
The cell decorative sheet is obtained, for example, by laminating paper on one side of a celluloid film.

Examples of the back sheet 2 include paper such as Japanese paper or non-woven fabric such as vinylon non-woven fabric and glass non-woven fabric. When Japanese paper is used as the back sheet, the binder is easily impregnated in the Japanese paper at the time of hot pressing, so that the wood fiber accumulation board and the back sheet (Japanese paper) are firmly adhered to each other. Preferred Japanese paper is Kozo,
Ginseng fiber such as mitsumata or gambi is used as a raw material, and paper is made with seri. Basis weight as the back sheet preferably has from about 20 to 200 g / m ^2, to hardly suppress warpage in basis weight is less than 20 g / m ^2, 200 g
/ M ² is economically disadvantageous.

Hereinafter, a method of manufacturing a backsheet-attached wood fiber integrated board will be described. The backsheet-attached wood fiber integrated board 3 shown in FIG. 2 has a length of 0.1 to 10 mm and a diameter of 2 to 300 μ occupying the majority, and a binder is attached to wood fibers having a water content of 15% by weight or less, The wood fibers to which the binder is attached are formed into a mat, and the back sheets 2 and 2 are laminated on both sides of the mat to form a laminate, and then the laminate is hot-pressed to cure the binder. Can be

The density distribution is 0.52 g / cm ^{3 to} 1.00
g / cm ³ and the density is 0.8 g / cm ^3.
If there is no layer having a thickness of ³ cm ³ or more,
When using a wood fiber accumulation board that exists only on the surface of less than 1 mm as a gauge board or the like that needs to drive nails of a pachinko machine, the nail holding force is large, and the nails are straightened evenly by an automatic nailing machine. You can beat. 0.8g / cm density
^{If a} layer having a thickness of ³ or more and a thickness exceeding 2 mm is present on the surface portion, it is difficult to drive the nail, and the nail is easily bent even when the nail is hit.
In addition, when a layer exceeding 2 mm exists on the surface, the rock layer on the surface can also be removed by cutting with a sander or the like.
The present invention achieves the objects. In addition, when the overall density (overall density) of the wood fiber accumulation board is 0.65 g / cm ³ or more, the holding force of the nail tends to be 40 kgf or more, and the nail is hard to come off from the wood fiber accumulation board. Therefore, such a wood fiber integrated board having a thickness t of 15 to 25 mm is useful for manufacturing a gauge board of a pachinko machine. The gauge board of the pachinko machine is a front plate for guiding the flow of the pachinko balls. The gauge board can be manufactured by providing a through hole in the wood fiber accumulation board of the present invention and nailing.

[0019]

The present invention will now be described by way of Examples and Comparative Examples.
Although specifically described, the present invention is not limited to only these examples. Example 1 The diameter is 0. About l ~ 1.0mm, length 0.2 ~ 50m
m of wood fiber is ground using a power mill (P-5) (manufactured by Dalton Co., Ltd.) and has a length in the range of 0.1 mm to 10 mm and a diameter of 2 to 300 μm. I got The water content of this wood fiber is 12% by weight
Met.

Next, the obtained wood fiber was put into a rotating drum rotating at a low speed, and a binder was spray-coated when the wood fiber dropped naturally in the drum. As a binder, crude polymethylene diphenyl diisocyanate (Sumitomo Bayer Urethane Co., trade name; Sumidur 4
4V20) 30% by weight and polyether polyol 20
A mixed solution in which 50% by weight of acetone was dissolved in 50% by weight of acetone was used. The amount of the binder applied was about 15 parts by weight based on 100 parts by weight of the absolute dry weight of the powdery wood fiber.

Next, the wood fiber coated with the binder was formed into a mat (thickness: about 400 mm) using a forming machine. Japanese paper on both sides of this mat-like material (the basis weight of this Japanese paper was 30 g / m ² )
Was located. The mat-like material and the Japanese paper were overlapped and press-formed between hot plates of a press to obtain a backsheet-attached wood fiber integrated board 3 shown in FIG. Heat pressure conditions are hot platen temperature 150 ° C, press pressure 20-30kgf
/ Cm ² and the pressing time was 20 minutes. As shown in FIG. 2, the backsheet-attached wood fiber integrated board 3
The paper (back sheet 2) was integrated on both sides of the wood fiber integrated board 1 obtained by bonding the a with the binder 1b at the time of hot pressing. The overall density of the portion of the wood fiber integrated board 1 attached to the back sheet 3 is 0.76 g / cm ³ , and the size is 500 mm wide × 4 length.
It was 50 mm x 20 mm thick.

When the obtained backsheet-attached wood fiber laminated board 3 was nailed with an automatic nailing machine, the nail was hit straight. The nail holding force of the nail was measured by a pull-out test, and the average value was 51.6 kgf.
The minimum value of the nail holding force is 45 kgf, and the maximum value is 55.
2 kgf and the number of measurements were 10. Density distribution in the thickness direction (Density Profile, Density P
The density distribution in the thickness direction of the portion of the wood fiber integrated board 1 was measured using a density distribution measuring device for measuring the density of the wood fiber. FIG. 4 shows the measurement results. As can be seen from FIG.
The maximum density of the surface is about 0.91 g / cm ³ (910 kg /
m ³ ), and the thickness of the bedrock layer having a density of 0.80 g / cm ³ or more was 1.20 mm. As a density distribution measuring device in the thickness direction, a standard manufactured by ATR (Germany) is used.
ATR Density Profiler
Type DPM201 was used.

Further, the obtained backsheet-attached wood fiber integrated board 3 is cut into a width of 460 mm and a length of 410 mm, and the cut product is placed at an ambient temperature of 35 ° C. and a relative humidity of 95% for 2 days, and then at an ambient temperature of 35%. C., 20% relative humidity for 5 days. Then, the cut product after the moisture resistance test was placed on a horizontal surface as shown in FIG. 3, and the lift c at the end was measured. The lift c at the end was 1 mm or less. That is, the backsheet-attached wood fiber integrated board 3 warps due to a change in humidity,
The twist was hard to occur.

COMPARATIVE EXAMPLE 1 13 beech veneers having a thickness of 1.5 mm were laminated and bonded so that their fiber directions were orthogonal to each other to obtain a 19.0 mm thick beech plywood. Then, when the beech plywood was measured for nail holding power in the same manner as in Example 1, the average value was 42.6 kg.
f. The minimum value of the nail holding force is 37.0 kg.
f, the maximum value was 47.3 kgf, and the measured number was 10.

Comparative Example 2 A water content of 18% by weight was used instead of the wood fiber in Example 1.
Instead of the mixture of 30% by weight of crude polymethylene diphenyl diisocyanate / 20% by weight of polyether polyol / 50% by weight of acetone in Example 1, 50% by weight of crude polymethylene diphenyl diisocyanate / acetone A wood fiber integrated board was obtained in the same manner as in Example 1 except that a mixed solution of 50% by weight was used. When the wood fiber accumulation board was nailed with an automatic nailing machine, the nail could not be straightened. The density distribution in the thickness direction of the wood fiber integrated board was measured in the same manner as in Example 1. FIG. 8 shows the measurement results. As shown in FIG. 8, the wood fiber accumulation board has a bedrock layer having a density of 0.80 g / cm ³ or more on both sides of the wood fiber accumulation board 1 with a thickness of 2 mm or more. It is estimated that he did not hit.

Examples 2 to 4 and Comparative Examples 3 to 5 The water content of the wood fibers obtained in the same manner as in Example 1 was adjusted to 12% by weight. The mixture obtained by mixing the wood fiber and the binder with a water content of 12% by weight was hot-pressed to obtain a wood fiber integrated board 1 shown in FIG. 1 having a thickness of about 20 mm. still,
By changing the composition of the binder as shown in Table 1 and changing the input amount of the wood fiber, Examples 2 to 4 and Comparative Examples 3 to
5, wood fiber integrated boards 1 having different overall densities were obtained. The nailing properties and nail holding power of the wood fiber integrated board 1 were measured. Also,
The density distribution of the wood fiber integrated board 1 in the thickness direction was measured by using a density distribution measuring device in the same manner as in Example 1 to obtain a density distribution of about 2
It was measured over 0 mm. The measurement results of the density distribution are shown in FIGS. 5 to 7 and FIGS.

Table 1 summarizes the measurement results of the nailing properties and the nail holding power of Examples 1-4 and Comparative Examples 2-5 together with the water content of the wood fiber and the composition of the binder. Also, FIG.
Table 1 shows the analysis results of the maximum density, the minimum density, the overall density, and the thickness of the surface layer having a density of 0.8 g / cm ³ or more, obtained from the graph shown in FIG. In Table 1, MDI / poly is a mixture of crude polymethylene diphenyl diisocyanate and polyether polyol, MDI / me / poly is a mixture of crude polymethylene diphenyl diisocyanate, melamine resin and polyether polyol, and melamine is melamine It means that a wood fiber integrated board was produced using a resin as a binder.

In Table 1, the nailing performance was evaluated as follows: a pachinko nail was hammered in with a metal hammer from a height of about 150 to 200 mm with a hand, and the nail that had been driven had no bend (marked with a circle in Table 1). When the nail was found to be bent, the nail was rejected (marked x in Table 1).
The nail holding force was determined by measuring the pull-out strength of a nail after driving a pachinko nail into a 50 × 50 mm square base plate. This strength measurement was performed according to JIS A5905-1994, 5.13.
The test was conducted in accordance with the wood screw holding force test method and the nail reverse pull-out resistance test method of 5.14. As a gauge board for a pachinko machine that requires durability, a nail holding force of about 40 kgf, preferably 50 kgf, is considered to be acceptable.

[0029]

[Table 1]

As can be seen from the columns of minimum density and maximum density in Table 1, the density distribution is in the range of 0.52 to 1.00 g / cm ³ , and the density is 0.80 g as shown in FIGS. / C
Even if it has a layer of m ³ or more as a surface layer on both front and back surfaces, the thickness of each of the surface layers is less than 2 mm, and FIGS.
As can be seen from FIG. 7, the wood fiber accumulation boards of Examples 1 to 4 in which the density distribution of the inner part from the surface layer is about 0.52 g / cm ³ or more and less than 0.8 g / cm ³ are not nail Excellent in nail holding power. In addition, it can be seen that when the binder is a polyether-based polyurethane, nailing properties and nail holding power are easily excellent.

[0031]

As described above, the wood fiber accumulating board of the present invention is excellent in nailability and nail holding power, hardly warps, and is particularly suitable for use as a gauge board for a pachinko machine. Further, according to the present invention, such a wood fiber integrated board can be easily manufactured.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of a wood fiber integrated board.

FIG. 2 is a cross-sectional view showing an example of a backsheet-attached wood fiber integrated board.

FIG. 3 is a cross-sectional view showing a method for measuring the amount of warpage of a wood fiber integrated board.

FIG. 4 is a graph showing a density distribution in the thickness direction of the wood fiber accumulation board of Example 1.

FIG. 5 is a graph showing a density distribution in the thickness direction of the wood fiber accumulation board of Example 2.

FIG. 6 is a graph showing a density distribution in the thickness direction of the wood fiber accumulation board of Example 3.

FIG. 7 is a graph showing a density distribution in the thickness direction of the wood fiber accumulation board of Example 4.

FIG. 8 is a graph showing the density distribution in the thickness direction of the wood fiber integrated board obtained in Comparative Example 2.

FIG. 9 is a graph showing the density distribution in the thickness direction of the wood fiber accumulation board of Comparative Example 3.

FIG. 10 is a graph showing the density distribution in the thickness direction of the wood fiber accumulation board of Comparative Example 4.

FIG. 11 is a graph showing a density distribution in a thickness direction of a wood fiber accumulation board of Comparative Example 5.

[Explanation of symbols]

1. Wood fiber laminated board, 1a .. Wood fiber, 1b. Binder, 1c .. Surface layer, 1d .. Core layer, 2. Backsheet, 3. Backwood laminated wood fiber laminated board

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] December 24, 1998 (1998.12.
24)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

5. The wood fiber integrated board according to claim 1, wherein the binder is a polyether-based polyurethane.

6. A backsheet-attached wood fiber accumulating board obtained by integrating a back sheet on at least one side of the wood fiber accumulating board according to any one of claims 1 to 5 .

7. A wood fiber is integrated by molding with a binder and has a density distribution of 0.52 g / cm ^{3 to} 1.0.
0 g / cm ³ and a density of 0.80 g / cm ³
A method for producing a wood fiber integrated board in which the above layer does not exist or has a thickness of less than 2 mm on the surface portion, wherein a binder is attached to the wood fiber having a water content of 15% by weight or less as the wood fiber, A method for producing a wood fiber integrated board, wherein the wood fibers to which the binder is attached are formed and the wood fibers are bound by the binder.

8. The wood fiber accumulating board according to claim 7 , wherein the wood fibers having a length of 0.1 mm to 10.0 mm and a diameter of 2 μm to 300 μm occupy most of the wood fibers. Manufacturing method.

9. A wood fiber stacking plate according to any one of claims 1 to 6 nails holding force of more than 40kgf wood
Gauge panel of pachinko machine using high quality fiber accumulation board.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction contents]

[0005]

According to the present invention, there is provided a wood fiber integrated board in which wood fibers are integrated by molding with a binder, and have a density distribution of 0.52 g / cm ^{3 to} 1.00 g / cm ^3.
In which no layer having a density of 0.80 g / cm ³ or more is present, or a wood fiber integrated board whose surface has a thickness of less than 2 mm. In the wooden-fiber stacking plate, it is preferable that the entire density thereof is ^{0.65g / cm 3 ~0.85g / cm 3} , is 0.1mm or more in length, 10.0
mm or less, it is preferable that wood fibers having a diameter of 2 μm to 300 μm occupy most of the wood fibers,
Binder is urea resin, melamine resin, phenol tree
Fat, polyurethane resin, epoxy resin or a mixture thereof
The binder is preferably a polyether-based polyurethane. The backsheet-attached wood fiber accumulation board is obtained by integrating a back sheet on at least one side of the wood fiber accumulation board. Preparation of wood fiber stacking plate of the present invention, the wood fibers are integrated by molding with the binder, the density distribution in the range of ^{0.52g / cm 3 ~1.00g / cm 3} , density of 0.80g / Cm ³ or a layer of wood fiber having a thickness of less than 2 mm on the surface thereof, wherein the wood fiber has a water content of 1
This is a method for producing a wood fiber integrated board in which a binder is attached to wood fibers of 5% by weight or less, the wood fibers to which the binder is attached are formed, and the wood fibers are bound by the binder. 10. In the manufacturing method, the length is 0.1 mm or more.
It is preferable that the wood fibers having a size of 0 mm or less and having a diameter of 2 μm to 300 μm occupy most of the wood fibers. The gauge panel of the pachinko machine according to the present invention is the above-mentioned wood fiber accumulation board, wherein the nail holding force is 40 kgf or more .

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Murakami 10-1, Nakazawa-cho, Hamamatsu-shi, Shizuoka Prefecture Inside the company (72) Inventor, Kanekoo 10-1 Nakazawa-cho, Hamamatsu-shi, Shizuoka Yamaha stock In-house (72) Inventor Satoshi Suzuki 10-1 Nakazawa-cho, Hamamatsu-shi, Shizuoka Yamaha Co., Ltd. F-term in the company (reference)

Claims (8)

[Claims] A wood fiber is integrated by molding with a binder and has a density distribution of 0.52 g / cm ^{3 to} 1.0.
0 g / cm ³ and a density of 0.80 g / cm ³
A wood fiber integrated board in which the above layers do not exist or whose thickness is less than 2 mm on the surface. 2. The total density is 0.65 g / cm ^{3 to} 0.8.
Wood fiber stacking plate according to claim 1, characterized in that the 5 g / cm ^3. 3. The wood fiber accumulation board according to claim 1, wherein the wood fibers having a length of 0.1 mm to 10.0 mm and a diameter of 2 μm to 300 μm occupy most of the wood fibers. 4. The wood fiber integrated board according to claim 1, wherein the binder is a polyether-based polyurethane. 5. A backsheet-attached wood fiber accumulator, comprising a backsheet integrated with at least one surface of the wood fiber accumulator according to any one of claims 1 to 4. 6. A wood fiber is integrated by molding with a binder, and has a density distribution of 0.52 g / cm ^{3 to} 1.0.
0 g / cm ³ and a density of 0.80 g / cm ³
A method for producing a wood fiber integrated board in which the above layer does not exist or has a thickness of less than 2 mm on the surface portion, wherein a binder is attached to the wood fiber having a water content of 15% by weight or less as the wood fiber, A method for producing a wood fiber integrated board, wherein the wood fibers to which the binder is attached are formed and the wood fibers are bound by the binder. 7. The length is 0.1 mm to 10.0 mm,
The method according to claim 6, wherein the wood fibers having a diameter of 2 m to 300 m occupy most of the wood fibers. 8. The gauge board of a pachinko machine according to claim 1, wherein the wood fiber accumulation board is a wood fiber accumulation board having a thickness of 15 mm to 25 mm.