JP2002248610A - Method for manufacturing fiber board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a fiber board capable of obtaining the fiber board which is high in strength and excellent in dimensional stability. SOLUTION: The method for manufacturing the fiber board comprises an adhesive agent feed process for feeding thermosetting resin aqueous solution 2 to a long fiber mat 1 comprising a long fiber aggregate to be obtained from at least one of kenaf, oil palm and coconut palm; a drying process for drying the long fiber mat 1 obtained in the drying process; and a forming process for forming the long fiber mat 1 obtained in the drying process into the fiber board by hot pressing. A plurality of kinds of resin components 4 and 5 of which the permeabilities into fibers 3 are different, are fed to the long fiber mat 1 by the adhesive agent feed process. The resin component 4 of which the permeability into the fibers 3 is high, permeates into a cell wall 6 of the fibers 3, and the resin component 5 of which the permeability into the fibers 3 is low, is stuck to a surface of the fiber 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to kenaf, oil palm,
The present invention relates to a method for producing a fiberboard using long fibers obtained from any one of coconut palms.

[0002]

2. Description of the Related Art Wood-based boards such as plywood, particle board, and MDF (medium fiber board) are used for building members such as flooring, wall and ceiling materials, door members, and building members such as skirting boards and surrounding edges. Used in a wide range of fields such as furniture materials.

[0003] These wood-based boards are formed into a plate shape by bonding a veneer, a piece of wood (particles), and a wood fiber, which are mainly obtained by processing softwood or hardwood. Therefore, it has characteristics such as stable quality, less anisotropy and excellent workability, as compared with a ground plate obtained by sawing raw wood.

On the other hand, due to global environmental problems in recent years, regulations on deforestation have been strengthened for the purpose of protecting the forest. There has been a growing demand for

In response to such demands, the development of boards using non-wood resources has been promoted, and non-wood lignocellulose such as bagasse, kolyan, oil palm (oil palm), jute, bamboo, etc. is used as a board material. Resources are starting to attract attention.

[0006] Regarding such boards utilizing non-wood resources, the present inventors have already disclosed in Japanese Patent Application Laid-Open No. H11-333886.
In the official gazette, kenaf (annual herbaceous mallow),
By using long fibers obtained from either oil palm or coconut as a raw material and orienting the long fibers in one direction or orthogonal direction, it is lightweight, high strength, and excellent in dimensional stability in the length direction. Is disclosed.

[0007] In the above-mentioned fiberboard, the bonding performance and the quality performance are mutually related, and a fiberboard having a sufficient bonding performance between fibers can be obtained with high strength and high performance. Are known. Therefore, in order to impart excellent performance to the fiberboard, it was essential to improve the adhesive performance. That is, it was necessary to uniformly apply an adhesive to a long fiber mat made of a long fiber aggregate having fiber directionality. In view of the demand for higher performance and lower cost, it is indispensable to establish a fiberboard manufacturing method for uniformly applying an adhesive to a long fiber mat.

As a method for producing a fiberboard for applying an adhesive to fibers, generally, a method of spraying an adhesive solution by using a spray or the like, a method of applying the adhesive solution by a roll, an adhesive solution A method in which the fiber is immersed (dipped) in a tank in which the fibers are placed. Among them, the dipping method is particularly preferably used from the viewpoint of uniformly applying the adhesive to the long fiber mat composed of the long fiber aggregate. Furthermore, the dipping method is used as an effective method because there is no problem such as scattering of the adhesive. Here, as the adhesive solution used in the above method, an aqueous adhesive solution is mainly used. This is because, compared with the case where a flammable dangerous substance such as an organic solvent is used, production with simple equipment is possible, and handling such as dilution is easy.

[0009] As a specific production process when an aqueous adhesive solution is used, first, a long fiber mat made of a long fiber aggregate obtained from at least one of kenaf, oil palm, and coconut is placed in an adhesive tank. A dipping step of applying an adhesive by dipping (adhesive supply step), a drying step of drying the obtained long fiber mat by blowing air, heating, etc. to remove excess water, and finally a drying step. After laminating a predetermined amount of the obtained long fiber mat, a molding step of heating and pressing to form a fiber board is used.

[0010]

However, in this method, in order to achieve higher performance and lower cost,
There were the following problems.

In the dipping method, since the adhesive is uniformly attached to the surface of the fiber, even if the amount of the adhesive is small, the fibers are firmly adhered to each other, and greatly contribute to the improvement of the strength performance after forming into a fiber board. However, improvement in strength and dimensional stability during water absorption and moisture absorption, which are important performances of the fiberboard, are small.

[0012] Kenaf, oil palm, coconut palm fiber itself,
Like wood fiber, it contains cellulose and hemicellulose as main components and has a large number of hydrophilic groups, so that it easily absorbs water and thereby swells easily. In addition, since the fiberboard is formed by heating and pressing during the manufacturing process, the fibers are compressed and the adhesive is cured, so that the deformation and compression of the fibers are fixed. Therefore, when moisture is absorbed by the fiberboard, the volume of the fiber itself expands and a force for recovering the deformation acts, so that the size easily changes greatly in the direction of the compressed thickness.

For this reason, there has been a demand for a new method for producing a fiberboard that can improve dimensional stability without impairing high strength.

The present invention has been made in view of the above points, and by controlling the application of an adhesive to fibers,
It is an object of the present invention to provide a method for producing a fiberboard having excellent performance, that is, a fiberboard capable of obtaining a fiberboard having high strength and excellent dimensional stability.

[0015]

According to a first aspect of the present invention, there is provided a method of manufacturing a fiberboard, comprising: setting a long fiber mat 1 comprising a long fiber aggregate obtained from at least one of kenaf, oil palm and coconut. Adhesive supplying step for supplying the aqueous solution of the conductive resin 2, drying step for drying the long fiber mat 1 obtained in the adhesive supplying step, and forming the long fiber mat 1 obtained in the drying step into a fiber board by hot pressing. In the method for producing a fiberboard comprising a molding step, a plurality of types of resin components 4 and 5 having different permeability into the fiber 3 are supplied to the long fiber mat 1 in an adhesive supplying step. . With this configuration, the resin component 4 having high permeability to the fiber 3 penetrates into the cell wall 6 of the fiber 3, and the resin component 5 having low permeability to the fiber 3 adheres to the surface of the fiber 3. For this reason, the resin component 4 hardened in the cell wall 6 suppresses the absorption of water into the fiberboard and also suppresses the swelling and deformation of the fiber 3 due to the water. The resin component 5 attached to the surface of the fiber 3 firmly bonds the fibers 3 to each other. Therefore, it is possible to manufacture a fiberboard having excellent dimensional stability while securing high strength.

According to a second aspect of the present invention, there is provided a fiberboard manufacturing method according to the first aspect of the present invention. Characterized in that the proportion of the resin component 4 having a high content is 10 to 80%. With this configuration, it is possible to stably and reliably manufacture a fiberboard having excellent dimensional stability while securing high strength.

According to a third aspect of the present invention, there is provided a method of manufacturing a fiberboard according to the first or second aspect, wherein a plurality of types of resin components having different permeability into the fiber are polymerized. It is characterized by a plurality of types of resin components having different degrees. With this configuration, the resin component 4, depending on the degree of polymerization,
5 can easily control the permeability to the fiber 3. That is, a resin component having a low degree of polymerization penetrates into the cell wall 6 of the fiber 3 as a resin component 4 having a high permeability to the fiber 3, and a resin component having a high degree of polymerization as a resin component 5 having a low permeability to the fiber 3 It adheres to the surface of the fiber 3. Therefore, it is possible to manufacture a fiberboard having excellent dimensional stability while securing high strength.

According to a fourth aspect of the present invention, there is provided a method for manufacturing a fiberboard, comprising the steps of:
The resin component 4 having high permeability to the fiber 3 is a phenol resin component having a degree of polymerization of 1. The phenol resin component having a degree of polymerization of 1, that is, a monomeric phenol resin component easily penetrates into the cell wall 6 of the fiber 3 and hardens while swelling the cell wall 6, has a bulking effect, and has a hydrophilic property in the fiber 3. Bonding with the base enhances the adhesion to the fiber 3 and makes it possible to manufacture a fiberboard having excellent dimensional stability.

According to a fifth aspect of the present invention, there is provided a method of manufacturing a fiberboard, comprising the steps of:
In the adhesive supplying step, the long fiber mat 1 is immersed in a thermosetting resin aqueous solution 2a containing a plurality of types of resin components 4 and 5 having different permeability to the fiber 3. With this configuration, the resin component 4 to the fiber 3,
5 can be simultaneously permeated and adhered, and a fiberboard excellent in dimensional stability can be manufactured by a simple method while maintaining high strength.

According to a sixth aspect of the present invention, there is provided a method for manufacturing a fiberboard, comprising the steps of:
In the adhesive supply step, after immersing the long fiber mat 1 in a thermosetting resin aqueous solution 2b containing a resin component 4 having a high permeability to the fiber 3, a resin component 5 having a low permeability to the fiber 3 is contained. The long fiber mat 1 is immersed in an aqueous thermosetting resin solution 2c. With this configuration, it is possible to individually control the penetration and adhesion of the resin components 4 and 5 to the fiber 3 in accordance with the type and properties of the fiber 3, so that a fiber board having further excellent strength and dimensional stability Can be manufactured.

According to a seventh aspect of the present invention, there is provided a method for manufacturing a fiberboard, comprising the steps of:
In the adhesive supply step, after immersing the long fiber mat 1 in a thermosetting resin aqueous solution 2b containing a resin component 4 having a high permeability to the fiber 3, a resin component 5 having a low permeability to the fiber 3 is contained. The thermosetting resin aqueous solution 2c to be sprayed is sprayed onto the long fiber mat 1 and adhered thereto. With this configuration, it is possible to individually control the penetration and adhesion of the resin components 4 and 5 to the fiber 3 according to the type and properties of the fiber 3.
By spraying a thermosetting resin aqueous solution 2c containing the resin component 5 having low permeability to the fibers 3, it is possible to easily control the adhesion of the resin component 5 to the fiber 3.
It is possible to manufacture a fiberboard having improved dimensional stability with improved strength.

According to a eighth aspect of the present invention, there is provided a fiberboard manufacturing method according to the sixth or seventh aspect, further comprising a resin component 4 having high permeability to the fibers 3. After dipping the long fiber mat 1 in the curable resin aqueous solution 2b, the water supplied to the long fiber mat 1 is dried, and then the resin component 5 having low permeability to the fiber 3 is supplied to the long fiber mat 1. It is characterized by the following. With this configuration, the resin component 4 that has penetrated into the fiber 3 is transferred to the cell wall 6 of the fiber 3.
Since the resin component 5 can be adhered to the surface of the fiber 3 after being stopped inside to make it difficult to flow out, it is possible to manufacture a fiber board having more excellent dimensional stability while securing high strength. .

According to a ninth aspect of the present invention, there is provided a method of manufacturing a fiberboard, comprising the steps of:
The thermosetting resin aqueous solution 2 is characterized by containing a thickener. With this configuration, the fibers 3 are reduced by reducing the permeability of the resin components 4 and 5 by containing a thickener.
It is possible to control the permeation and adhesion of the resin components 4 and 5 to the fiber 3 in accordance with the type and properties of the fiber, so that it is possible to manufacture a fiber board having improved strength and excellent dimensional stability. Will be possible.

A tenth aspect of the present invention is a fiberboard manufacturing method according to the ninth aspect, wherein the thickener is wheat flour. Since flour is inexpensive and has a large thickening effect, it is possible to produce a fiberboard having excellent dimensional stability at a low cost after further improving the strength.

[0025] Further, a fiberboard manufacturing method according to claim 11 of the present invention is characterized in that, in addition to the constitution of any one of claims 1 to 10, the thermosetting resin aqueous solution 2 contains a coagulant. Is what you do. With this configuration, by coagulating the molecules of the resin components 4 and 5 with the coagulant and depositing them on the surface of the fiber 3, the fiber 3
Since the permeation and adhesion of the resin components 4 and 5 to the fiber board can be controlled, it is possible to manufacture a fiber board having improved strength and excellent dimensional stability.

According to a twelfth aspect of the present invention, in addition to the structure of the eleventh aspect, the coagulant is aluminum sulfate. Aluminum sulfate, which is called a sulfuric acid band, is inexpensive and has a large agglomeration effect, so that it is possible to produce a fiberboard having improved strength and excellent dimensional stability at low cost.

Further, in the method for producing a fiberboard according to claim 13 of the present invention, in addition to the constitution of any one of claims 1 to 12, the thermosetting resin aqueous solution 2 contains a water repellent. It is assumed that. By the adhesive supply step, the water-repellent agent can be uniformly dispersed and impregnated in the long fiber mat 1, the absorption of water into the fiber board can be suppressed, and a fiber board excellent in dimensional stability can be manufactured. Will be possible.

[0028] A method of manufacturing a fiberboard according to a fourteenth aspect of the present invention is characterized in that, in addition to the structure of the thirteenth aspect, the water repellent is a wax emulsion. Since the wax emulsion is inexpensive and has a large water-repellent effect, it becomes possible to manufacture a fiberboard having excellent dimensional stability at low cost.

A fifteenth aspect of the present invention is directed to a fiberboard manufacturing method according to any one of the first to fourteenth aspects, wherein the aqueous thermosetting resin solution 2 contains formaldehyde. Things. With this configuration, the fibers 3 can be formalized with formaldehyde,
It is possible to produce a fiberboard having excellent dimensional stability.

[0030] Further, in the fiberboard manufacturing method according to claim 16 of the present invention, in addition to any one of the constitutions of claims 1 to 15, the aqueous thermosetting resin solution 2 contains glyoxal. Things. According to this configuration, the fiber 3 can be formalized with glyoxal, and a fiber board having excellent dimensional stability can be manufactured. Further, no formaldehyde is used or the amount of formaldehyde used can be reduced, and the emission of formaldehyde can be suppressed.

A method for manufacturing a fiberboard according to a seventeenth aspect of the present invention is characterized in that, in addition to any one of the first to sixteenth aspects, the thermosetting resin aqueous solution 2 contains a fatty acid salt. Is what you do. With this configuration, the fibers 3 can be esterified with the fatty acid salt, and a fiberboard having excellent dimensional stability can be manufactured.

[0032]

Embodiments of the present invention will be described below.

First, the penetration and adhesion of the resin component to the fiber will be described using kenaf as an example. FIG. 3A is a schematic view of a cross section of the kenaf fiber 3. One fiber 3 is composed of several to several tens of cells 10, in which a temporary conduit 11 which is a water passage and a cell wall 6 surrounding the temporary conduit 11. It should be noted that other fibers such as oil palm and coconut used in the present invention have substantially the same structure.

FIG. 3B is a schematic diagram of a cross section when a plurality of types of resin components 4 and 5 having different permeability into the fiber 3 are supplied to the fiber 3. By supplying a plurality of types of resin components 4 and 5 having different permeability to the fiber 3, the resin component 4 having a high permeability penetrates into the cell wall 6 of the fiber 3, while the resin component 5 having a low permeability has a cell wall 6. It cannot penetrate inside and adheres to the surface of the fiber 3. The resin component 4 that has penetrated into the cell wall 6 is cured in the cell wall 6 in the molding step, whereby it is possible to suppress the absorption of moisture into the fiberboard and to prevent swelling and deformation of the fiber 3 due to moisture. It can be suppressed. In addition, the resin component 5 attached to the surface of the fiber 3 is cured while being in close contact with other fibers 3 in the molding process, and thus the fibers 3 are firmly adhered to each other. Thus, it is possible to produce a fiberboard having excellent dimensional stability.

In the present invention, the long fiber mat 1 is made of a long fiber aggregate obtained from kenaf, oil palm, and coconut. One type of long fiber mat obtained from any one of kenaf, oil palm, and coconut is used. The long fiber mat 1 may be formed from a fiber aggregate, or the long fiber mat 1 may be formed by using two or more types of long fiber aggregates selected from kenaf, oil palm, and coconut. The method for forming the long fiber mat 1 is not particularly limited. For example, (1) a method in which a long fiber aggregate is cut in a length direction and a plurality of the fibers are stacked to form a mat. (2) A method of laminating long fiber aggregates and forming a mat using a device such as a cross layer or a needle punch. And the like.

The present invention relates to an adhesive for supplying and impregnating a thermosetting resin aqueous solution 2 containing at least one of a plurality of types of resin components 4 and 5 having different permeability into fibers 3 to the long fiber mat 1. A supply step, a drying step of drying the long fiber mat 1 impregnated with the thermosetting resin aqueous solution 2 in the adhesive supply step, and hot-pressing the dried long fiber mat 1 in the drying step, so that the long fiber mat 1 And a molding step of curing the resin components 4 and 5 impregnated into the fiberboard to form a fiberboard.

As the thermosetting resin aqueous solution 2, a thermosetting resin adhesive containing at least one of a plurality of types of resin components 4 and 5 having different permeability into the fiber 3 as a non-volatile component can be used. Further, when the viscosity of a thermosetting resin adhesive containing at least one of a plurality of types of resin components 4 and 5 having different permeability to the fiber 3 as a non-volatile component is large, the thermosetting resin adhesive is used. If necessary, it can be diluted with water to obtain a thermosetting resin aqueous solution 2. The thermosetting resin aqueous solution 2 is not limited to these. Further, the volatile component of the thermosetting resin adhesive used in the present invention is preferably water, but is not limited thereto, and a part or all of the volatile component is a known organic solvent conventionally applied to the adhesive. It may be.

In the present invention, the kind of the thermosetting resin of the thermosetting resin adhesive is not particularly limited. For example, among thermosetting resin adhesives that are heat-cured such as urea resin, melamine resin, phenol resin, resorcinol resin, urethane resin, furfural resin, and isocyanate resin, those having a high affinity for water can be exemplified. . In the present invention, the above thermosetting resin adhesives can be used alone or in combination.

In the present invention, the method of the drying step is not particularly limited, and examples thereof include drying by blowing air such as room temperature air or hot air and heating. In addition, a pressing operation may be performed with a roller or the like before drying by blowing or heating.

In the molding step of the present invention, the pressing temperature, the pressing time, the pressing pressure, etc., at the time of molding are appropriately set according to the type of the thermosetting resin adhesive used, the thickness of the fiberboard to be molded, and the like. It is. In addition, examples of a pressing method used in hot pressing include a batch type flat plate press and a continuous press, but are not particularly limited.

In the adhesive supply step of the present invention, when the resin components 4 and 5 are supplied and impregnated to the long fiber mat 1,
The weight ratio of the resin components 4 and 5 to the fiber weight of the long fiber mat 1 can be set by the dilution ratio of the aqueous thermosetting resin solution 2, the pressing operation, and the like, and the type of the thermosetting resin adhesive to be used and the molding method. Can be appropriately set depending on physical properties such as strength required for the fiberboard to be used. Further, the density of the fiberboard is not particularly limited.

In the present invention, of the resin components 4 and 5 supplied to the long fiber mat 1, the proportion of the resin component 4 having high permeability to the fiber 3 accounts for 10 to 80% by weight (mass ratio).
It is preferred that That is, the resin component 4 having high permeability is added to the resin component 4 having high permeability and the resin component 5 having low permeability which are supplied to the long fiber mat 1 in total of 100 parts.
Is preferably 10 to 80 parts. When the ratio of the resin component 4 having high permeability to the fiber 3 is less than 10%,
If the percentage of the resin component 4 penetrating into the fiber 3 becomes low and the dimensional stability may decrease, the ratio of the resin component 4 having a high permeability to the fiber 3 exceeds 80%. Since the proportion of the resin component 5 having low permeability to the fiber 3 is reduced and the resin component 5 attached to the surface of the fiber 3 is reduced, the strength may be reduced.

The plurality of types of resin components 4 and 5 having different permeability to the fiber 3 are preferably a plurality of types of resin components having different degrees of polymerization. The permeability of the thermosetting resin adhesive into the fiber 3 depends on the molecular weight, molecular size, molecular shape, molecular polarity of the resin component contained in the thermosetting resin adhesive, and the molecular weight of the thermosetting resin aqueous solution. Depends on viscosity and the like. A thermosetting resin adhesive adds a reactive group to a resin material of a monomer (monomer), and forms a polymer in a range that is soluble in water from the monomer to form a monomer and a polymer. And is cured by heating to form a three-dimensional structure. The difference in the degree of polymerization of the resin component of the thermosetting resin adhesive greatly changes the molecular weight, molecular size, and viscosity, so that the resin component 4 having a low degree of polymerization penetrates into the cell wall 6 of the fiber 3, The resin component 5 having a high degree of polymerization cannot penetrate into the cell wall 6 and adheres to the surface of the fiber 3. By this action, it is possible to manufacture a fiberboard having excellent dimensional stability while securing high strength.

In the present invention, examples of the resin component 4 having the highest permeability to the fiber 3 include a phenol resin component having a polymerization degree of 1, that is, a monomer. As the monomeric phenol resin component, phenol, monomethylolphenol, dimethylolphenol, trimethylolphenol, and the like shown in Chemical Formula 1 can be used. Examples of the resin component 5 having a lower permeability than the resin component 4 having the highest permeability include a phenol resin component having a degree of polymerization of 2 or more, such as a dimeric phenol resin component shown in [Chemical Formula 2]. be able to.

It has been confirmed that the monomeric phenol resin component contained in the phenol resin adhesive has a small molecular size and penetrates into the cell wall 6 of the fiber 3. Then, the phenolic resin component in the cell wall 6 is hardened while the cell wall 6 is swollen, and does not expand any more even if water enters (bulk effect). Further, since the phenolic resin component binds to the hydrophilic group in the fiber, it is possible to suppress the invasion of water after forming the fiberboard, and it is possible to manufacture a fiberboard having excellent dimensional stability. Become.

[0046]

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[0047]

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FIG. 1 shows an embodiment of the present invention.
In this embodiment, in the adhesive supply step shown in FIG. 1A, as the thermosetting resin aqueous solution 2, a thermosetting resin containing a plurality of types of resin components 4 and 5 having different permeability into the fiber 3 is used. By immersing the long fiber mat 1 in this thermosetting resin aqueous solution 2a stored in the immersion tank 20 using the aqueous solution 2a, the thermosetting resin aqueous solution 2a
Is supplied for impregnation. The thermosetting resin aqueous solution 2a containing a plurality of types of resin components 4 and 5 having different permeability into the fiber 3 is a thermosetting resin adhesive containing only a highly permeable resin component 4 as a resin component or a permeable resin. Thermosetting resin adhesive in which the content ratio of the resin component 4 having a high content is higher than that of the resin component 5 having a low permeability, and a thermosetting resin containing only the resin component 5 having a low permeability to the fiber 3 as a resin component An adhesive or a thermosetting resin adhesive in which the content of the resin component 5 having low permeability to the fiber 3 is larger than that of the resin component 4 having high permeability is mixed, and the mixed thermosetting resin adhesive is mixed. If necessary, it can be prepared by diluting with water.

After the adhesive supply step as described above, FIG.
In the drying step shown in (b), air is blown to the long fiber mat 1 as indicated by an arrow, and the thermosetting resin aqueous solution 2a impregnated in the long fiber mat 1 is removed and dried. After this drying step, the dried long fiber mat 1 is placed between a pair of press plates 12 of a hot-press device (hot press) 15 by a forming step shown in FIG. The resin components 4, 5 of the thermosetting resin adhesive impregnated in the long fiber mat 1 are sandwiched between the plates 12 and heated and pressed.
Is polymerized, and the thermosetting resin adhesive is cured to form a fiberboard.

In this embodiment, since the aqueous thermosetting resin solution 2a containing plural kinds of resin components 4 and 5 having different permeability into the fiber 3 is used, the resin component 4 to the fiber 3 of the long fiber mat 1 is used. 5, the penetration and adhesion of 5 can be performed simultaneously in one dipping operation, a simpler method than the case of performing multiple dipping operations, a fiber board with excellent dimensional stability while ensuring high strength It can be manufactured.

As described above, of the resin components 4 and 5 supplied to the long fiber mat 1, the proportion of the resin component 4 having high permeability to the fiber 3 occupies 10 to 80 in weight ratio (mass ratio).
% Of the thermosetting resin aqueous solution 2a.
The proportion of the resin component 4 having high permeability in the inside is preferably set to 10 to 80% by weight. That is, the thermosetting resin aqueous solution 2a contains 10 to 80 parts of the resin component 4 having a high permeability with respect to 100 parts in total of the resin component 4 having a high permeability and the resin component 5 having a low permeability. Is preferred.

FIG. 2 shows another embodiment of the present invention.
In this embodiment, in the adhesive supply step, a thermosetting resin aqueous solution 2b containing a resin component 4 having high permeability to fibers 3 and a resin having low permeability to fibers 3 are used as thermosetting resin aqueous solution 2. Thermosetting resin aqueous solution 2 containing component 5
c.

That is, as shown in FIG.
After dipping the long fiber mat 1 in a thermosetting resin aqueous solution 2b containing a resin component 4 having a high permeability to the fiber 3, the resin component 5 having a low permeability to the fiber 3 is contained as shown in FIG. The long fiber mat 1 is immersed in the thermosetting resin aqueous solution 2c to be heated, so that the thermosetting resin aqueous solution 2
b and 2c are supplied and impregnated. Both of the thermosetting resin aqueous solutions 2b and 2c are stored in the immersion tank 20.

The thermosetting resin aqueous solution 2b containing the resin component 4 having high permeability to the fiber 3 contains the resin component 4 having high permeability more than the resin component 5 having low permeability. Preferably, 90 parts or more of the highly permeable resin component 4 is contained with respect to 100 parts in total of the highly permeable resin component 4 and the low permeable resin component 5. Such a thermosetting resin aqueous solution 2b is a thermosetting resin adhesive containing only a resin component 4 having a high permeability as a resin component or a resin component 5 having a low content of the resin component 4 having a high permeability. It can be prepared by diluting a thermosetting resin adhesive, which is larger than the above, with water as needed.

The aqueous thermosetting resin solution 2c containing the resin component 5 having low permeability to the fiber 3 contains the resin component 5 having low permeability more than the resin component 4 having high permeability, and in particular, It is preferable that 90 parts or more of the low-permeability resin component 5 is contained based on 100 parts in total of the high-permeability resin component 4 and the low-permeability resin component 5. Such a thermosetting resin aqueous solution 2c is a thermosetting resin adhesive containing only a resin component 5 having low permeability as a resin component or a resin component 4 having a high content of the resin component 5 having low permeability. It can be prepared by diluting a thermosetting resin adhesive, which is larger than the above, with water as needed.

After the adhesive supply step as described above, FIG.
The fiberboard can be formed by performing the drying step shown in (c) and the forming step shown in FIG. 2D in the same manner as in the above embodiment.

In this embodiment, a thermosetting resin aqueous solution 2 b containing a resin component 4 having high permeability to the fiber 3 is provided.
Since the thermosetting resin aqueous solution 2c containing the resin component 5 having low permeability to the fiber 3 is separately prepared and used, the fiber 3
It is possible to individually control the penetration and adhesion of the resin components 4 and 5 to the fiber 3 according to the type and properties of the fiber 3, so that it is possible to manufacture a fiber board having further excellent strength and dimensional stability. It becomes something. That is, for example, in the case of the fiber 3 in which the resin component 4 hardly penetrates, the thermosetting resin aqueous solution 2b containing the resin component 4 having high permeability to the fiber 3
Fibers 3 that are hardly immersed in
In the case of (1), it is possible to easily immerse in the thermosetting resin aqueous solution 2c containing the resin component 5 having low permeability to the fiber 3 for a long time, and thus the type and properties of the fiber 3 Accordingly, it is possible to manufacture a fiber board having further excellent strength and dimensional stability.

In the embodiment shown in FIG.
Instead of the step shown in (b), namely, a thermosetting resin aqueous solution 2c containing a resin component 5 having low permeability to the fiber 3
Instead of immersing the long fiber mat 1 in the thermosetting resin aqueous solution 2c containing the resin component 5 having low permeability to the fiber 3.
Can be attached to the long fiber mat 1 by spraying. Thus, the resin component 5 having low permeability to the fiber 3
When spraying the thermosetting resin aqueous solution 2c containing the above, the thermosetting resin adhesive may be sprayed as it is without being diluted with water, or may be sprayed after being diluted with water.

As described above, the thermosetting resin adhesive containing the resin component 5 having low permeability to the fiber 3 is sprayed onto the long fiber mat 1 by spraying and adhered thereto.
The penetration and adhesion of the resin components 4 and 5 to the fiber 3 can be individually controlled in accordance with the type and properties of the resin 3, and in particular, the adhesion of the resin component 5 to the surface of the fiber 3 can be easily controlled. This makes it possible to produce a fiberboard having improved strength and excellent dimensional stability. That is, in the case of the fiber 3 to which the resin component 5 does not easily adhere, a large amount of the thermosetting resin adhesive containing the resin component 5 having low permeability to the fiber 3 is supplied.
Since this can be easily performed, it is possible to manufacture a fiber board having further excellent strength and dimensional stability in accordance with the type and properties of the fibers 3.

In the embodiment shown in FIG. 2 and the embodiment using a spray in the step of FIG. 2B, the thermosetting resin aqueous solution 2b containing the resin component 4 having high permeability to the fiber 3 is long. After the fiber mat 1 is immersed, the water supplied to the long fiber mat 1 is dried, and then, into a thermosetting resin aqueous solution 2c containing a resin component 5 having low permeability to the fiber 3,
The dried long fiber mat 1 is immersed, or a thermosetting resin aqueous solution (thermosetting resin adhesive) 2c containing a resin component 5 having low permeability to the fiber 3 is sprayed on the dried long fiber mat 1. Preferably, it is sprayed and adhered.

After the long fiber mat 1 is immersed in the thermosetting resin aqueous solution 2b containing the resin component 4 having high permeability to the fiber 3, the long fiber mat 1 is dried. The water component is removed and the resin component 4 is converted into the fiber 3
The resin component 4 that has permeated the fiber 3 is stopped in the cell wall 6 of the fiber 3 and the resin component 5 can be adhered to the surface of the fiber 3. Thus, it is possible to produce a fiberboard having further excellent dimensional stability while ensuring the above.

In the present invention, the thermosetting resin aqueous solution 2
(2a to 2c) may contain a thickener. When preparing the aqueous thermosetting resin solution 2 by diluting the thermosetting resin adhesive, the thickener may be added to the thermosetting resin adhesive before being diluted with water, or may be added to the thermosetting resin adhesive. After diluting the adhesive in water, a thickener may be added to the aqueous solution.

As described above, when the aqueous thermosetting resin solution 2 contains a thickener, the permeability of the resin components 4 and 5 can be reduced. It is possible to control the penetration and adhesion of the resin components 4 and 5 to the fiber board, and therefore, it is possible to manufacture a fiberboard having excellent dimensional stability while improving strength. . That is, for example, in the case of the fiber 3 in which the resin component 4 easily penetrates, the viscosity is increased by adding a thickener to the thermosetting resin aqueous solution 2a, 2b containing the resin component 4 having high permeability to the fiber 3. By doing so, the permeability of the resin component 4 having high permeability to the fiber 3 is reduced, and thus the strength is improved in accordance with the type and properties of the fiber 3. This makes it possible to produce a fiberboard having excellent dimensional stability.

Further, the content of the thermosetting resin adhesive having a high permeability to the fiber 3, ie, the content of the resin component 4 having a high permeability to the fiber 3 is more extreme than the content of the resin component 5 having a low permeability. (For example, a thermosetting resin adhesive containing 90 parts or more of the highly permeable resin component 4 with respect to a total of 100 parts of the highly permeable resin component 4 and the low permeable resin component 5) Thermosetting resin aqueous solution 2 using resin adhesive)
Even when a and b are prepared, the thickener can control the penetration and adhesion of the resin components 4 and 5 to the fibers 3.

As the above-mentioned thickener, carboxymethylcellulose and wheat flour can be used, but wheat flour is preferably used. Flour is inexpensive and has a large thickening effect, so that it is possible to produce a fiberboard having excellent dimensional stability at a low cost after further improving the strength.

In the present invention, a coagulant may be contained in the thermosetting resin aqueous solution 2 (2a to 2c). When diluting the thermosetting resin adhesive to prepare the thermosetting resin aqueous solution 2, the coagulant may be added to the thermosetting resin adhesive before being diluted with water, or may be added to the thermosetting resin adhesive. After diluting the agent in water, a coagulant may be added to the aqueous solution.

As described above, since the thermosetting resin aqueous solution 2 contains a coagulant, the molecules of the resin components 4 and 5 can be coagulated with the coagulant and deposited on the surface of the fiber 3.
Since the permeation and adhesion of the resin components 4 and 5 to the fiber 3 can be controlled according to the type and properties of the fiber 3, a fiber board having improved strength and excellent dimensional stability can be manufactured. Is what makes it possible. That is, for example,
In the case of the fiber 3 into which the resin component 4 easily penetrates, the coagulant is contained in the thermosetting resin aqueous solution 2a, 2b containing the resin component 4 having high permeability to the fiber 3, so that the permeability to the fiber 3 is increased. This is to reduce the permeability of the resin component 4 having a high resin content. In this way, a fiber board having excellent dimensional stability after improving the strength corresponding to the type and properties of the fiber 3 is manufactured. It is possible to do.

Further, the content of the thermosetting resin adhesive having a high permeability to the fiber 3, that is, the content of the resin component 4 having a high permeability to the fiber 3 is more extreme than the content of the resin component 5 having a low permeability. (For example, a thermosetting resin adhesive containing 90 parts or more of the highly permeable resin component 4 with respect to a total of 100 parts of the highly permeable resin component 4 and the low permeable resin component 5) Thermosetting resin aqueous solution 2 using resin adhesive)
Even when a and b are prepared, the permeation and adhesion of the resin components 4 and 5 to the fiber 3 can be controlled by the flocculant.

As the above coagulant, it is preferable to use aluminum sulfate. Aluminum sulfate is also called sulfuric acid band, which is inexpensive and has a large coagulation effect, so that it is possible to produce fiberboard with excellent dimensional stability at low cost after further improving strength. It is.

In the present invention, a water repellent may be contained in the thermosetting resin aqueous solution 2 (2a to 2c). When preparing the thermosetting resin aqueous solution 2 by diluting the thermosetting resin adhesive, the water repellent may be added to the thermosetting resin adhesive before being diluted with water, or the thermosetting resin may be added. After diluting the adhesive in water, a flocculant may be added to the aqueous solution.

Since the aqueous thermosetting resin solution 2 contains a water repellent as described above, the water repellent can be uniformly dispersed and impregnated in the long fiber mat 1 by the adhesive supplying step, and It is possible to suppress the absorption of water into the fiberboard and to manufacture a fiberboard having excellent dimensional stability. That is, for example, in the case of using the highly water-absorbing fiber 3, by incorporating a water-repellent agent, it is possible to suppress the absorption of moisture into the fiberboard. Thus, it is possible to manufacture a fiber board having excellent dimensional stability.

As the water repellent, a silicone oil emulsion or a wax emulsion can be used, but a wax emulsion is preferably used.
Because wax emulsions are inexpensive and have a large water-repellent effect,
This makes it possible to produce a fiberboard excellent in dimensional stability at low cost.

In the present invention, the thermosetting resin aqueous solution 2 (2a to 2c) may contain at least one of formaldehyde and glyoxal. When diluting the thermosetting resin adhesive to prepare the thermosetting resin aqueous solution 2, formaldehyde or glyoxal may be added to the thermosetting resin adhesive before being diluted with water, or the thermosetting resin adhesive may be added. After diluting the adhesive in water, formaldehyde or glyoxal may be added to the aqueous solution.

By adding formaldehyde and glyoxal to the aqueous thermosetting resin solution 2 as described above, formaldehyde and glyoxal can be uniformly dispersed and impregnated in the long fiber mat 1 in the adhesive supply step. By hot-pressing the fiber mat 1 in the molding step, the fiber 3 can be formalized with formaldehyde or glyoxal. The formalization of the fiber 3 is a reaction in which a hydroxyl group in the fiber 3 reacts with formaldehyde or glyoxal to crosslink between the hydroxyl groups. Since the hydroxyl group in the fiber 3 decreases, the absorption of water into the fiberboard is suppressed. This makes it possible to produce a fiberboard having excellent dimensional stability.

When glyoxal is used, no formaldehyde is used or the amount of formaldehyde used can be reduced, and the emission of formaldehyde during the manufacturing process can be suppressed. No measures are needed to prevent the environment from deteriorating.

In the present invention, the thermosetting resin aqueous solution 2 may contain a fatty acid salt. When the thermosetting resin aqueous solution 2 is prepared by diluting the thermosetting resin adhesive,
The fatty acid salt may be added to the thermosetting resin adhesive before being diluted with water, or after diluting the thermosetting resin adhesive with water,
A fatty acid salt may be added to this aqueous solution.

Since the aqueous thermosetting resin solution 2 contains a fatty acid salt as described above, the fatty acid salt can be uniformly dispersed and impregnated in the long fiber mat 1 by the adhesive supply step. The fiber 3 can be esterified with a fatty acid salt by hot-pressing 1 in a molding step. Esterification of fiber 3 is fiber 3
The reaction between the hydroxyl groups and the fatty acid salt in the reaction is a cross-linking reaction between the hydroxyl groups. Since the number of the hydroxyl groups in the fiber 3 decreases, the absorption of water into the fiberboard is suppressed. This makes it possible to produce a fiberboard having excellent dimensional stability. The type of the fatty acid salt is not particularly limited, and examples thereof include sodium stearate, which is a main component of soap.

As described above, the case where two components, the resin component 4 having high permeability to the fiber 3 and the resin component 5 having low permeability to the fiber 3 are supplied to the long fiber mat 1 has been described. In the present invention, three or more components having different permeability into the fiber 3 can be supplied to the long fiber mat 1.

[0079]

The present invention will be described below in detail with reference to examples.
You. Hereinafter, “%” means “% by mass” unless otherwise specified.
(% By weight) ". (Example 1) A long fiber aggregate of kenaf bast was laminated,
Kenaf long fiber mat obtained using a Rosslayer machine
(Fiber length: about 0.2-2m, fiber diameter: about 50-6
00 μm, mat surface weight: 0.24 g / cm^Two)
First, a fiberboard was produced by the following procedure. Long fiber mat
The size is 300 × 900mm and the surface weight is 0.24g / cm
^TwoMet. Phenolic tree as thermosetting resin adhesive
Fat adhesive A (non-volatile content specified by JIS K6833)
55%, the ratio of resin components having a degree of polymerization of 1 to 9 in the nonvolatile components is 9
1%, 9% of a resin component having a degree of polymerization of 2 or more) and phenol
Resin adhesive B (55% of non-volatile content,
Resin component ratio of polymerization degree 1 4%, resin degree of polymerization 2 or more
(A ratio of 96%) was used by mixing at a ratio of 1: 1. Adhesive supplier
The process is to dilute the mixed adhesive with water and add
After immersing the fiber mat for 10 seconds, press
Go to the fiber weight (impregnation) resin nonvolatile
Adjustment was performed so that the ratio of the weight per minute was 25%. this
In the subsequent drying process, air at 50 ° C is sent to the long fiber mat.
And the ratio of the weight of water to the weight of fiber becomes 10%.
Drying was carried out until. Further, in the molding step, the molding temperature 16
0 ° C, molding pressure 2.94MPa (30kgf / c
m^Two), Press under the condition of molding time 5 minutes,
Molded. The size of the obtained fiberboard is 300 × 900m
m, thickness 4 mm, and board specific gravity 0.80. (Example 2) Kenaf long fiber obtained in the same manner as in Example 1
A fiberboard was prepared using a fiber mat. As adhesive
Enol resin adhesive C (non-volatile content 48%, non-volatile content
Of which, a resin component ratio of polymerization degree 1 is 21% and a polymerization degree is 2 or more.
(Resin component ratio: 79%). Adhesive supply process and drying
The steps and molding steps were performed under the same conditions as in Example 1. (Example 3) Kenaf long fiber obtained in the same manner as in Example 1
A fiberboard was prepared using a fiber mat. As adhesive
Using phenolic resin adhesive A and phenolic resin adhesive B
Was. The adhesive supply step includes a phenol resin adhesive A
Was diluted with water, and a long fiber mat was immersed in this for 10 seconds.
Then, squeeze with a transport roller and apply to the fiber weight.
The ratio of the resin non-volatile content to be given (impregnated) becomes 15%.
Adjustments were made as follows. After that, this long fiber mat is
Immerse in the diluted aqueous solution of phenolic resin adhesive B for 10 seconds
After immersion, squeeze it with a transport roller to reduce fiber weight.
Of total weight of resin non-volatile content to be applied (impregnated)
Was adjusted to be 25%. Drying and molding processes are actual
The conditions were the same as in Example 1. (Example 4) Kenaf long fiber obtained in the same manner as in Example 1
A fiberboard was prepared using a fiber mat. As adhesive
Using phenolic resin adhesive A and phenolic resin adhesive B
Was. The adhesive supply step includes a phenol resin adhesive A
Was diluted with water, and a long fiber mat was immersed in this for 10 seconds.
Then, squeeze with a transport roller and apply to the fiber weight.
The ratio of the resin non-volatile content to be given (impregnated) becomes 15%.
After drying, dry in a dryer at 60 ° C for 20 minutes
Was done. Then, this filament mat was diluted with water.
After immersing in an aqueous solution of the enol resin adhesive B for 10 seconds,
Squeezed by transport roller to give to fiber weight
25% of the total weight of the resin non-volatile content (impregnated)
Adjustment was made so that The drying and molding steps are the same as in Example 1.
The same conditions were used. (Example 5) Kenaf long fiber obtained in the same manner as in Example 1
A fiberboard was prepared using a fiber mat. As adhesive
Using phenolic resin adhesive A and phenolic resin adhesive B
Was. The adhesive supply step includes a phenol resin adhesive A
Was diluted with water, and a long fiber mat was immersed in this for 10 seconds.
Then, squeeze with a transport roller and apply to the fiber weight.
The ratio of the resin non-volatile content to be given (impregnated) becomes 15%.
Adjustments were made as follows. After that, the filament mat
Apply (impregnate) the knol resin adhesive B to the fiber weight
So that the proportion of the total weight of the resin non-volatile content is 25%
Spraying was performed with a spray. The drying and molding steps are the same as in Example 1.
The same conditions were used. (Example 6) Kenaf long fiber obtained in the same manner as in Example 1
A fiberboard was prepared using a fiber mat. As adhesive
An enol resin adhesive A and a melamine resin adhesive were used.
In addition, this melamine resin adhesive is combined with a resin component having a polymerization degree of 1.
A resin component having a degree of polymerization of 2 or more and the above phenol resin adhesive
It contains the same degree as B.

In the adhesive supply step, the phenolic resin adhesive A was diluted with water, a long fiber mat was immersed in this for 10 seconds, and then squeezed with a transport roller to give (impregnate) the fiber weight. Resin non-volatile content weight ratio is 1
After adjusting to 5%, the content was adjusted to 20% in a 60 ° C. drier.
Drying was performed for minutes. Thereafter, the long fiber mat is immersed in an aqueous solution of a melamine resin adhesive diluted with water for 10 seconds, and then squeezed by a conveying roller to obtain the total weight of the resin non-volatile component applied (impregnated) to the fiber weight. 25%
% Was adjusted. Drying and molding process is Example 1
The same conditions were used. (Example 7) A fiberboard was produced using the kenaf long fiber mat obtained in the same manner as in Example 1. A phenol resin adhesive A and a melamine resin adhesive were used as the adhesive.
The melamine resin adhesive contains a resin component having a degree of polymerization of 1 and a resin component having a degree of polymerization of 2 or more to the same extent as the phenol resin adhesive B.

In the adhesive supply step, the phenolic resin adhesive A was diluted with water, the long fiber mat was immersed in the water for 10 seconds, and then squeezed with a transport roller to give (impregnate) the fiber weight. Resin non-volatile content weight ratio is 1
Adjustment was made to be 5%. Thereafter, the long fiber mat was sprayed with a spray so that the ratio of the total weight of the resin non-volatile components applied (impregnated) to the fiber weight with respect to the fiber weight was 25%. The drying and molding steps were performed under the same conditions as in Example 1. (Example 8) A fiber board was produced using the kenaf long fiber mat obtained in the same manner as in Example 1. The adhesive used was phenol resin adhesive C to which 1% of carboxymethyl cellulose was added as a thickener based on the resin non-volatile content. The adhesive supply step, drying step, and molding step were performed under the same conditions as in Example 1. (Example 9) A fiber board was produced using the kenaf long fiber mat obtained in the same manner as in Example 1. The adhesive used was phenol resin adhesive C to which flour was added as a thickener at 2% of the resin non-volatile content. The adhesive supply step, drying step, and molding step were performed under the same conditions as in Example 1. (Example 10) A fiberboard was produced using the kenaf long fiber mat obtained in the same manner as in Example 1. As the adhesive, a phenol resin adhesive C to which 1% hydrochloric acid was added as a coagulant by 1% based on the resin non-volatile content was used. The adhesive supply step, drying step, and molding step were performed under the same conditions as in Example 1. (Example 11) A fiberboard was produced using the kenaf long fiber mat obtained in the same manner as in Example 1. The adhesive used was a phenolic resin adhesive C to which a 1% aqueous solution of aluminum sulfate was added as a coagulant, 2% based on the non-volatile content of the resin. The adhesive supply step, drying step, and molding step were performed under the same conditions as in Example 1. (Example 12) A fiber board was produced using the kenaf long fiber mat obtained in the same manner as in Example 1. As the adhesive, a phenol resin adhesive C to which a silicone oil emulsion was added as a water repellent at 1% relative to the resin non-volatile content was used. The adhesive supply step, drying step, and molding step were performed under the same conditions as in Example 1. (Example 13) A fiber board was produced using the kenaf long fiber mat obtained in the same manner as in Example 1. As the adhesive, a phenol resin adhesive C to which a wax emulsion as a water repellent was added at 2% with respect to the resin non-volatile content was used. The adhesive supply step, drying step, and molding step were performed under the same conditions as in Example 1. (Example 14) A fiber board was produced using the kenaf long fiber mat obtained in the same manner as in Example 1. As the adhesive, a phenol resin adhesive C to which a 20% aqueous formaldehyde solution was added by 10% based on the resin non-volatile content was used. The adhesive supply step, drying step, and molding step were performed under the same conditions as in Example 1. (Example 15) A fiber board was produced using the kenaf long fiber mat obtained in the same manner as in Example 1. As the adhesive, a phenol resin adhesive C to which a 40% aqueous glyoxal solution was added in an amount of 5% based on the resin non-volatile content was used. The adhesive supply step, drying step, and molding step were performed under the same conditions as in Example 1. (Example 16) A fiber board was produced using the kenaf long fiber mat obtained in the same manner as in Example 1. As the adhesive, a phenol resin adhesive C to which sodium stearate was added at 2% based on the resin non-volatile content was used. The adhesive supply step, drying step, and molding step were performed under the same conditions as in Example 1. (Comparative Example 1) A fiber board was produced using the kenaf long fiber mat obtained in the same manner as in Example 1. Phenol resin adhesive A was used as the adhesive. The adhesive supply step, drying step, and molding step were performed under the same conditions as in Example 1. (Comparative Example 2) A fiber board was manufactured using the kenaf long fiber mat obtained in the same manner as in Example 1. Phenol resin adhesive B was used as the adhesive. The adhesive supply step, drying step, and molding step were performed under the same conditions as in Example 1.

For the fiberboards prepared in Examples 1 to 16 and Comparative Examples 1 and 2, JIS A5905 (fiberboard)
The peel strength and the water-absorbing thickness expansion coefficient specified in the above were tested, and the results are shown in Table 1.

[0083]

[Table 1]

As shown in Table 1, Comparative Example 1 has a very low peel strength. In the phenolic resin adhesive A used in Comparative Example 1, the component having a degree of polymerization of 1 occupies 90% or more, and most of the resin components in the phenolic resin adhesive A penetrate into the cell wall 6 of the fiber 3 and the fiber 3 It is considered that the resin component in the phenolic resin adhesive A adhered to the surface of the resin was slight. In Comparative Example 2, the coefficient of expansion of the water absorption thickness exceeds 20%, and the coefficient of expansion is extremely large. In the phenol resin adhesive B used in Comparative Example 2, the components having a degree of polymerization of 2 or more account for 90% or more, and most of the resin components in the phenol resin adhesive B cannot penetrate into the cell wall 6 of the fiber 3. Conceivable. In comparison with Comparative Examples 1 and 2, it was confirmed that Examples 1 to 16 of the present invention all had a reduced water absorption thickness expansion coefficient. In addition, in comparison with Comparative Example 2, it was confirmed that Examples 1 to 16 can ensure that the fiberboard has the same or higher peel strength.

[0085]

As described above, according to the first aspect of the present invention, a thermosetting resin aqueous solution 2 is supplied to a long fiber mat composed of a long fiber aggregate obtained from at least one of kenaf, oil palm and coconut palm. An adhesive supplying step, a drying step of drying the long fiber mat obtained in the adhesive supplying step, and a forming step of forming the long fiber mat obtained in the drying step into a fiber board by hot pressing. In the production method, a plurality of types of resin components having different permeability to the fiber are supplied to the long fiber mat by the adhesive supply step, so that the resin component having a high permeability to the fiber penetrates into the cell wall of the fiber, The resin component having low permeability to the fiber adheres to the surface of the fiber. For this reason, the resin component cured in the cell wall suppresses the absorption of water into the fiberboard and also suppresses the swelling and deformation of the fiber due to the water. Thus, it is possible to manufacture a fiberboard having excellent dimensional stability while securing high strength.

In the invention of claim 2 of the present invention, of the resin component supplied to the long fiber mat, the proportion of the resin component having high permeability to the fiber is 10 to 80%, so that the high strength can be obtained. Thus, it is possible to stably and reliably manufacture a fiberboard having excellent dimensional stability while securing the same.

Further, according to the invention of claim 3 of the present invention, since a plurality of types of resin components having different permeabilities into fibers are a plurality of types of resin components having different degrees of polymerization, the resin components have different degrees of polymerization. It is possible to easily control the permeability to the fiber, apply an adhesive to the cell wall of the fiber and to the surface of the fiber, and manufacture a fiber board with excellent dimensional stability while maintaining high strength. Is what makes it possible.

Further, according to the invention of claim 4 of the present invention, the resin component having high permeability to the fiber is a phenol resin component having a degree of polymerization of 1, so that the phenol resin component having a degree of polymerization of 1, that is, a monomeric phenol resin component is used. It easily penetrates into the cell wall of the cell and hardens while swelling the cell wall.
In addition to having an effect, it is bonded to the hydrophilic group in the fiber, so that the adhesion to the fiber is enhanced, and it is possible to produce a fiber board having excellent dimensional stability.

Further, according to the invention of claim 5 of the present invention, in the adhesive supplying step, the long fiber mat is immersed in a thermosetting resin aqueous solution containing a plurality of types of resin components having different permeability to the fiber. In addition, it is possible to simultaneously infiltrate and adhere the resin component to the fiber, and it is possible to manufacture a fiber board having excellent dimensional stability while ensuring high strength by a simple method.

The invention according to claim 6 of the present invention is characterized in that, in the adhesive supplying step, the long fiber mat is immersed in a thermosetting resin aqueous solution containing a resin component having high permeability to the fiber, Since the long fiber mat is immersed in a thermosetting resin aqueous solution containing a resin component with low permeability, it is necessary to individually control the penetration and adhesion of the resin component to the fiber according to the type and properties of the fiber. This makes it possible to produce a fiberboard excellent in strength and dimensional stability.

Further, according to the invention of claim 7 of the present invention, in the adhesive supplying step, the long fiber mat is immersed in a thermosetting resin aqueous solution containing a resin component having a high permeability to the fiber, and then the fiber is added to the fiber. The thermosetting resin aqueous solution containing a resin component with low permeability is sprayed and attached to the long fiber mat by spraying, so that the penetration and attachment of the resin component to the fiber can be individually performed according to the type and properties of the fiber. In particular, by spraying a thermosetting resin aqueous solution containing a resin component with low permeability to fibers, it is easy to control the adhesion of the resin component with low permeability to fibers. Thus, it is possible to manufacture a fiber board having excellent dimensional stability after improving strength.

[0092] The invention of claim 8 of the present invention provides the method of manufacturing a fiberboard according to claim 6 or 7, wherein the aqueous solution of the thermosetting resin containing the resin component having a high permeability to the fiber contains the long fiber. After the mat is immersed, the moisture supplied to the long fiber mat is dried, and then the resin component having low permeability to the fiber is supplied to the long fiber mat. Stop it and make it hard to leak,
A resin component can be adhered to the surface of the fiber, and a fiber board having further excellent dimensional stability can be manufactured while maintaining high strength.

Further, according to the invention of claim 9 of the present invention, since the thermosetting resin aqueous solution contains a thickening agent, even when an adhesive having high permeability is used, the addition of the thickening agent can be achieved. By reducing the permeability of the resin component, it is possible to control the penetration and adhesion of the resin component to the fiber in accordance with the type and properties of the fiber, and to improve the strength and to have excellent dimensional stability. It becomes possible to manufacture a fiberboard.

The tenth aspect of the present invention is that, since the thickener is wheat flour, the flour is inexpensive and has a large thickening effect, so that the strength is further improved and the dimensional stability is improved. An excellent fiberboard can be manufactured at low cost.

Further, according to the invention of claim 11 of the present invention, since the thermosetting resin aqueous solution contains an aggregating agent, even when an adhesive having high permeability is used, the molecular weight of the resin component is reduced by the aggregating agent. By agglomerating and depositing on the surface of the fiber,
It is possible to control the penetration and adhesion of the resin component to the fiber according to the type and properties of the fiber, and it is possible to manufacture a fiber board with excellent dimensional stability after improving the strength It is.

Further, the invention of claim 12 of the present invention relates to a fiber which has an excellent dimensional stability after further improving strength since aluminum sulfate is inexpensive and has a large flocculating effect because aluminum flocculant is aluminum sulfate. The plate can be manufactured at low cost.

According to the invention of claim 13 of the present invention, since the aqueous thermosetting resin solution contains a water repellent, the water repellent is uniformly dispersed and impregnated in the long fiber mat in the adhesive supplying step. Thus, the absorption of moisture into the fiberboard is suppressed, and a fiberboard having excellent dimensional stability can be manufactured.

Further, in the invention of claim 14 of the present invention, since the water-repellent agent is a wax emulsion, the wax emulsion is inexpensive and has a large water-repellent effect. It is possible to do.

The fifteenth aspect of the present invention is that, since the thermosetting resin aqueous solution contains formaldehyde, the fibers can be formalized with formaldehyde.
This makes it possible to produce a fiberboard having excellent dimensional stability.

Further, according to the invention of claim 16 of the present invention, since the aqueous thermosetting resin solution contains glyoxal, the fiber can be formalized with glyoxal and a fiber board excellent in dimensional stability can be manufactured. Although it is possible to formalize the fiber, it is possible to use no formaldehyde or reduce the amount of formaldehyde used,
It can suppress the emission of formaldehyde.

Further, according to the seventeenth aspect of the present invention, since the thermosetting resin aqueous solution contains a fatty acid salt, the fiber 3 can be esterified with the fatty acid salt, and a fiber board excellent in dimensional stability can be obtained. It can be manufactured.

[Brief description of the drawings]

FIG. 1 shows an example of an embodiment of the present invention, and (a) to (c) are schematic views.

FIG. 2 shows another example of the above, and (a) to (d) are schematic views.

FIG. 3A is a schematic view of a cross section showing kenaf fiber,
(B) is a schematic diagram of a cross section showing kenaf fibers supplied with a plurality of types of resin components having different permeability.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Long fiber mat 2 Thermosetting resin aqueous solution 2a Thermosetting resin aqueous solution 2b Thermosetting resin aqueous solution 2c Thermosetting resin aqueous solution 3 Fiber 4 Resin component 5 Resin component

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Kazunori Umeoka 1048 Kazumasa Kadoma, Osaka Pref.Matsushita Electric Works, Ltd. F-term (reference) 2B260 AA03 AA12 BA07 BA15 BA19 CA02 CB01 CD02 CD06 DA02 DA03 DA04 DA05 DA17 DB21 DC01 DC15 EA05 EB01 EB02 EB05 EB06 EB19 EB42

Claims (17)

[Claims] 1. An adhesive supply step of supplying a thermosetting resin aqueous solution to a long fiber mat composed of a long fiber aggregate obtained from at least one of kenaf, oil palm and coconut, and an adhesive supply step. In the method of manufacturing a fiberboard, comprising a drying step of drying the long fiber mat and a molding step of forming the long fiber mat obtained in the drying step into a fiberboard by hot pressing, the adhesive supply step allows the fiber permeability to be increased. A plurality of types of resin components different from each other are supplied to a long fiber mat. 2. The ratio of the resin component having high permeability to fibers among the resin components supplied to the long fiber mat is 10%.
The method for producing a fiberboard according to claim 1, wherein the content is from 80% to 80%. 3. The method for producing a fiberboard according to claim 1, wherein the plurality of types of resin components having different permeability to the fibers are a plurality of types of resin components having different degrees of polymerization. 4. The method for producing a fiberboard according to claim 1, wherein the resin component having high permeability to the fiber is a phenol resin component having a degree of polymerization of 1. 5. The method according to claim 1, wherein in the adhesive supplying step, the long fiber mat is immersed in a thermosetting resin aqueous solution containing a plurality of types of resin components having different permeability to the fiber. A method for producing a fiberboard according to any one of the above. 6. In the adhesive supply step, after immersing the long fiber mat in a thermosetting resin aqueous solution containing a resin component having a high permeability to fibers, a resin component having a low permeability to fibers is contained. The method for producing a fiberboard according to any one of claims 1 to 4, wherein the long fiber mat is immersed in an aqueous thermosetting resin solution. 7. In the adhesive supply step, the long fiber mat is immersed in a thermosetting resin aqueous solution containing a resin component having high permeability to fibers, and then contains a resin component having low permeability to fibers. The method for producing a fiberboard according to any one of claims 1 to 4, wherein the thermosetting resin aqueous solution is sprayed and adhered to the long fiber mat by spraying. 8. The method for producing a fiberboard according to claim 6, wherein the long fiber mat is immersed in a thermosetting resin aqueous solution containing a resin component having high permeability to fibers, and then the long fiber mat is formed. A method for producing a fiberboard, comprising drying supplied water, and then supplying a resin component having low permeability to fibers to a long fiber mat. 9. The method for producing a fiberboard according to claim 1, wherein the aqueous thermosetting resin solution contains a thickener. 10. The method for producing a fiberboard according to claim 9, wherein the thickener is wheat flour. 11. The method according to claim 1, wherein the aqueous thermosetting resin solution contains a coagulant. 12. The method according to claim 11, wherein the coagulant is aluminum sulfate. 13. The method for producing a fiberboard according to claim 1, wherein the aqueous thermosetting resin solution contains a water repellent. 14. The method according to claim 13, wherein the water repellent is a wax emulsion. 15. The method for producing a fiberboard according to claim 1, wherein the aqueous thermosetting resin solution contains formaldehyde. 16. The method for producing a fiberboard according to claim 1, wherein the aqueous thermosetting resin solution contains glyoxal. 17. The method for producing a fiberboard according to claim 1, wherein the aqueous thermosetting resin solution contains a fatty acid salt.