JP2882262B2 - Wood board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wooden board, and
The present invention relates to a wooden board made by laminating a plurality of directional wood thin laminated boards in which wood flakes are adhered using a binder to form and integrate.

[0002]

2. Description of the Related Art In recent years, shortage of timber resources and protection of forests have become problems, and it is clear that deforestation will become more and more difficult in the future. Therefore, plywood made by bonding and laminating a plurality of veneer veneers and the like, and using a large amount of raw wood, the supply is unstable or insufficient,
Along with that, flooring, etc., which used plywood conventionally,
It is expected that manufacturing will be difficult due to a shortage of materials or a rise in material costs.

[0003] Accordingly, attention has been paid to wood flakes obtained by effectively utilizing thin wood pieces and wood fibers of wood pieces which have been conventionally discarded, and application to fields where plywood was conventionally used is expected. I have. Such a wooden board is called an oriented strand board, and is generally formed by bonding and shaping components such as wood flakes using a binder. Therefore, by changing the molding die, it is possible to relatively easily obtain a material having the required size and shape. It can also improve the properties, preservability, flame retardancy, etc., and have characteristics not found in natural wood.

[0004] Such a wooden board tends to have a higher density than natural wood or plywood using the same. If the board is made thicker in order to improve the strength, the weight increases and the handling is increased. There were problems such as becoming difficult. Therefore, wood flakes and the like are molded and integrated using a foamable binder to generate minute voids inside the plate material, thereby reducing the density while maintaining the strength and imparting flexibility.

[0005] However, such a wooden board has a problem in moisture resistance as compared with plywood or the like, and is not suitable for use under high humidity conditions. Specifically, there has been a problem that the material expands by absorbing moisture or the weight is significantly increased.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a wood board which is made of a directional wood flake assembly formed by integrating wood flakes with a binder and has high moisture resistance.

[0007]

An object of the present invention is to provide a core layer composed of at least one directional wood lamination plate in which wood flakes are bonded and molded using a binder, and laminated on both sides of the core layer. And a surface layer composed of a directional wood lamella laminated plate formed by bonding wood lamellas using a binder and forming and integrating the flakes, and the binder comprises a foamable resin and a non-foamable resin in a ratio of 4: 1 to 1: 1 . The problem can be solved by a wooden board characterized by being mixed in a ratio.

Hereinafter, the wood board of the present invention will be described in detail. FIG. 1 is a view showing an example of a wood board of the present invention,
In the figure, reference numeral 1 denotes a core layer formed of one piece of directional wood lamella laminated and integrated by using a binder.
Has a three-layer laminated structure in which a surface layer 2 composed of a directional laminated wood lamella formed integrally with a binder is laminated on both surfaces of the laminate.

Here, the term "directional wood thin plate assembly" refers to a wood board material which is formed by integrating the wood grain directions in one direction and accumulating, forming and integrating them. However, it is not necessary that all the wood pieces constituting the directional wood piece assembly board be arranged in one direction, and the grain direction of about 70% or more of the wood pieces may be arranged in one direction.

[0010] In the directional wood lamella assembly forming the core layer 1 and the surface layer 2 of the wood board of the present invention, the wood lamellas are adhered with a binder and are integrally formed. The binder used here binds the wood flakes to each other in the surface layer 1 and foams itself. Preferably, the binder is present only at the intersection of the wood flakes, By using a foam cell to expand small gaps in the wood flakes, the amount of resin used is reduced and the density of the core layer is reduced.

The binder used in the present invention is preferably a mixture of a foamable resin and a non-foamable resin.
These mixing ratios can be appropriately adjusted according to the density of the target wooden board or the like, but the mixing ratio between the foamable resin and the non-foamable resin is 4: 1 to 1: 1. Reduce the foaming resin content to less than 1/2 or more than 4/5
Then, the moisture resistance of the obtained wooden board decreases.

Here, the foamable resin may be composed of a self-foaming resin, or may be composed of a non-foamable resin and a foaming agent. An example of the self-expanding resin is an expandable polyurethane resin. Examples of the non-foamable resin foamed by the foaming agent include a polyurethane resin, a polystyrene resin, an epoxy resin, a polyvinyl chloride resin, a phenol resin, a urea resin, and a mixture thereof. Examples of the foaming agent include CCl ₃ F, CCl ₂ F ₂ ,
Or a volatile blowing agent such as CCl ₂ F—ClF ₂ , for example, azodicarbonamide, azohexahydrobenzonitrile, 2,2′-azoisobutyronitrile, benzenesulfohydrazide, or N, N′-dinitroso-N ,
A thermally decomposable blowing agent such as N'-dimethyl terephthalamide can be used.

Examples of the non-foamable resin mixed with the foamable resin include urea resin, melamine resin, phenol resin, polystyrene resin, epoxy resin, polyvinyl chloride resin and a mixture thereof. .

The wood flakes forming the core layer 1 of the wooden board of the present invention preferably have a length of 50 to 75 mm, a width of 6 to 50 mm, and a thickness of 0.1 to 0.8 mm. The wood flakes forming the surface layer 2 have a length of 50 to 100 m.
m, a width of 6 to 100 mm, and a thickness of 0.1 to 0.8 mm are preferably used. Further, it is preferable that the thickness of the wood flakes forming the surface layer 2 be 0.3 mm or less, because the surface smoothness of the obtained wooden board is further improved. As these wood flakes, flakes such as Japanese red pine, larch, Scots pine, Abies sachalinensis, aspen, lodgepole pine and the like are preferably used, but the tree species is not particularly limited.

It is preferable that the wood flakes forming the surface layer 2 be acetylated in advance. When the wood flakes are acetylated, the wood flakes are dried until the water content becomes 3% or less, preferably 1% or less, and then acetic acid, acetic anhydride,
It is preferable to acetylate in the gas phase (acetylation degree: 12 to 20%) by contacting with vaporized vapor such as chloroacetic acid.

The amount of the binder applied to the core layer and the wood flakes constituting the surface layer of the wooden board of the present invention is 5 to 15% by weight (hereinafter, referred to as the total weight of the wood flakes and the binder in each layer).
The weight percent of the binder is preferably the weight percent of the resin contained in the binder relative to the plate material). If the amount of the binder is less than 5% by weight, the moisture resistance of the wooden board is reduced, and if it is more than 15% by weight, the effect of improving the moisture resistance is not enhanced, and the density is increased and the wood feeling is impaired.

In the wooden board of the present invention, it is preferable to laminate a surface layer made of the same type of directional laminated wood board on both sides of the core layer. The thickness of the front layer is preferably the same as the front and back sides, but the ratio of the thickness of the core layer to the thickness of the front layer (the sum of the thicknesses of the front and back sides) is not particularly limited. To increase the strength, it is preferable to increase the thickness of the surface layer. Furthermore, the arrangement direction of the wood flakes forming the core layer and surface layer, it is preferable to be arranged to Cartesian together. Further, in the present invention, the one obtained by applying a binder to the wood flakes forming the core layer and the one obtained by applying the binder to the wood flakes forming the surface layer are dry-formed, and the surface layer and the core layer are simultaneously hot-pressed. Is preferred.

Concretely, first, a binder obtained by applying a binder to a thin piece of wood to be one surface layer 2 on a hot pressing plate is sprayed so that the arrangement direction thereof is substantially constant. those binder is applied to the wood flakes forming the arrangement direction of the wooden strands are sprayed so as to arrangement direction Cartesian wood flakes forming the surface layer 2. Furthermore, the other surface layer 2
Are coated with a binder onto the thin wood pieces forming the surface layer 2, and are scattered so as to be parallel to the arrangement direction of the thin wood pieces forming the surface layer 2 to obtain a three-layer laminate.

Next, the three-layer laminate is subjected to hot-press simultaneous molding by applying hot pressure in a hot-press forming machine. The heat and pressure conditions are preferably such that the pressure is 1 to 2 MPa, the temperature is 150 to 200 ° C., and the time is the desired thickness (mm) × 5 to 120 seconds.

According to the wood board of the present invention, the wood flakes are particularly improved in the heat resistance by bonding and integrating the thin wood pieces with a binder comprising a mixture of a foaming resin and a non-foaming resin in a predetermined ratio. There are features. In the above description, a three-layer laminated wooden board material in which a directional wood laminate plate serving as a surface layer is laminated on both surfaces of a core layer made of one directional wood laminate laminate is described. There is no limitation, and for example, a laminated structure of a total of four or more layers, that is, a core layer formed by laminating two or more directional wood laminate laminated boards and surface layers formed on both surfaces thereof can be used. Also in this case, regardless of the number of stacked layers, the arrangement direction of the wood flakes between directional wooden strands assembled plate adjacent are preferably be arranged so as to Cartesian together.

In the woody board of the present invention, the directional wood flakes constituting the core layer and the surface layer have the bending strength in the arranging direction particularly improved because the wood flakes are arranged in substantially the same direction. In addition, since the molding is integrally formed using a binder containing a foamable resin, the density of the obtained wooden board material is low, and it has a large bending strength. Further, by setting the mixing ratio of the foamable resin and the non-foamable resin of the binder within a predetermined range, the moisture resistance of the wooden board can be significantly improved.

Next, the wood board of the present invention will be specifically described based on examples. (Example 1) Length is 50 to 75 mm, width is 6 to 50 m
m, a thin piece of aspen having a thickness of 0.1 to 0.8 mm was produced by a shaving machine (manufactured by Iwakura Gumi). The weight ratio of the foamable urethane resin (44V20, manufactured by Sumitomo Bayer) to the non-foamable aqueous emulsion phenolic resin is 0: 100, 25:75, 50:50, 75:
Twenty parts by weight of each of the five types of binder mixtures changed to 25 and 100: 0 were prepared. Next, 100 parts by weight of the above-mentioned wood flakes were put into a rotating drum rotating at a low speed, and were sprinkled by spraying when the wood flakes dropped naturally in the drum, whereby five types of binder mixtures were applied to the wood flakes.

First, a thin piece of wood to which five kinds of binder mixtures were applied was sprayed on a hot pressing plate so as to form a laminate of a surface layer / core layer / surface layer.
For 5 minutes, five types of wooden boards were produced by hot-press molding simultaneously. For each of the prepared wooden boards, the water absorption thickness expansion coefficient was measured by JA.
S Measured based on "structural panel". The water-absorbing thickness expansion coefficient is a ratio of the increase in thickness after immersing the plate material in water for 72 hours, as a ratio to the thickness before immersion. The results are shown in FIG. In the figure, the abscissa indicates the content ratio of the phenol resin in the binder mixture. When the ratio of the non-foamable resin in the binder mixture peaks at about 25% and is higher or lower, the water absorption thickness expansion coefficient tends to increase, that is, the water resistance tends to decrease.

(Example 2) Thin pieces of aspen having a length of 50 to 75 mm, a width of 6 to 50 mm, and a thickness of 0.1 to 0.8 mm were produced by a shaving machine (manufactured by Iwakura Gumi Co., Ltd.). did. A binder comprising a 2: 1 mixture of a foamable urethane resin (44V20, manufactured by Sumitomo Bayer) and a non-foamable aqueous emulsion phenol resin is prepared, and 100 parts by weight of the above-mentioned wood flakes are placed in a rotating drum rotating at a low speed. And the binder was applied to the thin wood pieces for the surface layer by spraying when spraying naturally when falling in the drum. At that time, the amount of the foamable binder to be applied was changed from 3 to 18% by weight.

The wood flakes coated with the binder are coated on the surface layer /
Sprayed on a hot pressing plate so as to form a laminate of core layer / surface layer, at a temperature of 160 ° C. and a pressure of 2 MPa so as to have a thickness of 12 mm
And heat and pressure simultaneously for 20 minutes.
Various kinds of wood board were made. The thickness expansion coefficient of water absorption was measured for each of the six types of wood boards. The results are shown in FIG. Within the measured range, increasing the binder amount increased the coefficient of expansion of the water absorption thickness and tended to improve the moisture resistance. However, it was found that when the binder content exceeded about 12%, even if the binder amount was increased, the value was hardly improved.

(Example 3) As a material of a directional laminated wood laminated plate constituting a core layer, a length of 50 to 75 mm and a width of 6 to 5 were used.
A 0 mm thin slice of aspen was produced with a shaving machine (manufactured by Iwakura Gumi). 12 parts by weight of a binder composed of a mixture of a foaming urethane resin (44V20, manufactured by Sumitomo Bayer) and a non-foaming aqueous emulsion type phenol resin in a weight ratio of 2: 1 were prepared, and the above-mentioned mixture was placed in a rotating drum rotating at a low speed. 88 parts by weight of wood flakes
The binder was applied to the wood flakes for the core layer by spraying when spontaneously falling in the drum.

As a material for the directional thin wood laminated plate constituting the surface layer, aspen flakes having a length of 50 to 100 mm and a width of 6 to 100 mm were produced by a shaving machine (manufactured by Iwakura Gumi Co., Ltd.). Foamable urethane resin (44V2
0, manufactured by Sumitomo Bayer Co., Ltd.) and 12 parts by weight of a foaming binder made of a mixture of a non-foaming aqueous emulsion-type phenolic resin at a weight ratio of 2: 1. 88 parts by weight of the binder were applied by spraying when naturally falling in the drum, and the binder was applied to the thin wood piece for the surface layer.

First, half of the surface-layer wood flakes to which the binder has been applied are arranged in a substantially constant direction on a hot-press plate and sprayed, and the core-layer wood flakes to which the binder has been applied are laid thereon. Spreading was performed so that the arrangement direction of the wood flakes was perpendicular to the arrangement direction of the surface wood flakes. Further, on top of this, the remaining surface-layer wood flakes were arranged in the same direction as the surface-layer wood flakes that were first scattered, and scattered to form a three-layer laminate. The laminated body was heated at a temperature of 160 ° C. and a pressure of 2 MPa for 2 hours.
Hot-press molding was performed for 0 minutes. The thickness of the obtained wooden board is 1
2 mm and a density of 0.61 g / cm ³ .

Example 4 The wood board of the present invention prepared in Example 3 was measured for the coefficient of expansion of water absorption thickness based on JIS. According to the JIS standard, the immersion time in water is 24 hours. Further, a normal peel strength test and a boiling peel strength test based on JAS were performed. Table 1 shows the results. In Table 1, as a result of the boiling peel test, when no peeling was observed, it was indicated by ○, and when peeling occurred partially, it was indicated by △.

Comparative Example 1 The same measurement as in Example 4 was performed on a plywood (standard water-resistant type) having the same thickness as in Example 3. Table 1 shows the results.

(Comparative Example 2) The same measurement as in Example 4 was performed on a plywood (completely water-resistant type) having the same thickness as in Example 3. Table 1 shows the results.

(Comparative Example 3) A conventional directional wood flake assembly obtained by molding and integrating wood flakes with 2% by weight of a non-foamable binder, and having the same thickness as the wood board of Example 3 The same measurement as in Example 4 was performed on the laminated board. Table 1 shows the results.

[0033]

(Example 5) The woody board of the present invention produced in Example 3, the plywood of Comparative Example 1, and the directional lamella of Comparative Example 3 were immersed in water for 72 hours based on JAS. After that, the weight increase rate was measured to evaluate the moisture resistance.
The results were expressed as a ratio of the weight increase after immersion to the weight before immersion. The results are summarized in Table 2.

[0035]

(Example 6) For the woody board of the present invention produced in Example 3, and the plywood and directional thin wood laminated boards of Comparative Examples 1 to 3, the screw holding force in the plane direction and the direction of the edge of the wood was measured according to JIS.
It measured based on. Table 3 shows the results.

[0037]

From these results, the wood board of the present invention was
It is understood that the plywood has moisture resistance superior to that of the conventional plywood, and has a screw holding force equal to or greater than that of the conventional plywood and the directional thin wood laminated board.

(Example 7) The bending value of the wooden board of the present invention produced in Example 3 was measured based on JAS. For example, according to the JAS standard for flooring materials, the value of this bending deflection needs to be 3.5 mm or less. As a result, the bending deflection of the wooden board of Example 3 was 3.0 mm.
It was found that the floor material standard of AS was satisfied.

[0040]

The wood board according to the present invention has a core layer made of a laminated wood lamella obtained by molding and integrating wood flakes using a binder, and a directional material obtained by molding and integrating wood flakes on both sides using a binder. By laminating a surface layer composed of a wood lamella, the binder is obtained by mixing a foamable resin and a non-foamable resin at a predetermined ratio, and by further setting the content of the binder within a predetermined range, In particular, it is possible to obtain a low-density, high-strength wood board having high moisture resistance.
In addition, the wood board of the present invention has a large screw retaining force, and therefore, the wood board of the present invention can be applied to applications where plywood such as flooring and wall material is conventionally used. Furthermore, by acetylating the thin wood pieces constituting the surface layer, insect repellency, preservation, antibacterial properties, and dimensional stability of the wooden board can be improved. ADVANTAGE OF THE INVENTION According to the wooden board | plate material of this invention, the raw material conventionally used as a waste material can be used effectively, and there exists an effect which protects a wood resource. Further, such a raw material is inexpensive, and the cost of the raw material can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a wooden board of the present invention.

FIG. 2 is a graph showing the relationship between the composition of a binder and the coefficient of expansion of water absorption thickness of a wooden board obtained using the binder.

FIG. 3 is a graph showing the relationship between the content of a binder and the coefficient of expansion of water absorption thickness of a wood board obtained using the binder.

[Explanation of symbols]

 1 ... core layer, 2 ... surface layer

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kazushi Endo 10-1 Nakazawa-cho, Hamamatsu-shi, Shizuoka Yamaha Corporation (56) References JP-A-7-88813 (JP, A) JP-A-6-88 312411 (JP, A) JP-A-6-285820 (JP, A) JP-A 4-126809 (JP, U) JP-B 4-55083 (JP, B2) JP-B 35-30185 (JP, Y1) (58) Field surveyed (Int. Cl. ⁶ , DB name) B27N 3/00-3/04

Claims (3)

(57) [Claims] 1. A core layer composed of at least one laminated piece of wood flakes formed by bonding and integrating a piece of wood with a binder, and laminated on both sides of the core layer, and bonding the wood flakes with a binder. It comprises a surface layer made of a directional wood laminate laminated plate that is molded and integrated, and the binder is obtained by mixing a foamable resin and a non-foamable resin in a ratio of 4: 1 to 1: 1. Wood board. 2. The resin content of the binder is as follows:
5 to 1 based on the total weight of the binder and the wood flakes
The wood material according to claim 1, wherein the content is 5% by weight. 3. The wooden board according to claim 1, wherein the foamable resin is a foamable urethane resin, and the non-foamable resin is a phenol resin.