JP2005219241A - Woody molded product and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a woody molded product such as a woody floor material or the like enhanced in strength by mutually bonding wood materials by a thermosetting resin and improved in its defect such as easiness to stain or the like. <P>SOLUTION: The woody molded product 1 having a predetermined thickness is composed of finely divided woody materials and the thermosetting resin for mutually bonding woody materials and formed so that the filling density of the woody materials becomes low from one side of the woody molded product 1 to the other side in the thickness direction of the woody molded product 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a wood molded body comprising a segmented wood material and a thermosetting resin, and a method for producing the same. For example, the present invention relates to a wooden molded body used as a flooring or wall material for a house.

Floor materials and walls made of solid materials such as wooden materials (hereinafter referred to as wooden floor materials) make people feel the unique softness and warmth. This is due to the characteristics of the wood material itself such as the void structure (a structure in which a plurality of temporary road pipes are gathered together).
On the other hand, wooden flooring has a drawback that it is easily soiled and easily damaged.
As an example of improving the above-mentioned drawbacks, there is means for applying a coating to the surface of a wooden flooring or the like (see Patent Document 1). By covering the surface of a wooden flooring or the like with a high-density coating layer, the above-mentioned drawbacks can be solved. Easy to clean. However, since there is a high-density coating layer at the part where the person and the wooden flooring or the like come into contact, the properties of the wooden flooring and the like will depend exclusively on the properties of the coating layer. In other words, the softness and warmth resulting from the characteristics of woody materials are lost. In addition, the humidity control function of the wood material is lost, so it gives a crisp feeling when touched by a person.
Therefore, as a method for solving the problem, a method of manufacturing a molded body (see Patent Document 2) in which a high melting point thermoplastic resin is bonded with a low melting point thermoplastic resin and the density gradually increases in the thickness direction is referred to as a wood material. It may be applied to Since the surface of the molded body manufactured by this manufacturing method is a low-density layer, the person who touched the surface does not feel the above-mentioned sensation, and if the surface becomes dirty or damaged, the surface becomes dirty. It is conceivable to remove scratches and dirt on the surface by removing the surface by means such as scraping a damaged part.
JP 2001-334506 A JP 2001-322137 A

However, when the above manufacturing method is applied to a wood material, if a thermoplastic resin is used as the wood material adhesive, a strong adhesive force cannot be obtained, and the strength of the produced molded body itself is slightly insufficient. . For this reason, the strength of the manufactured molded body itself is insufficient. As a result, the above-described molded body cannot be used for members that require strength, such as floor materials that support people, furniture, and the like, and wall materials that hold the structure of the house.
Furthermore, in the manufacturing method of a molded body comprising a thermoplastic resin as a constituent element, it is necessary to cool (cooling process) in order to fix the molded body in a desired shape state in the manufacturing process, and the production tact is long. There was a problem.
The present invention has been devised in view of the above points. That is, the problem to be solved by the present invention is to provide a wooden flooring or the like that improves the strength of the wooden molded body by bonding the wooden materials to each other with a thermosetting resin, and also improves defects such as the ease of soiling. It is in.
Furthermore, the problem to be solved by the present invention is to simplify the manufacturing process of the wood molded body by utilizing the characteristics of a thermosetting resin that is cured by applying heat.

In order to solve the above problems, each invention of the present invention takes the following means.
First, a wood molded body according to the first invention is a wood molded body having a predetermined thickness, which is composed of a segmented wood material and a thermosetting resin that joins the wood materials, In the thickness direction, the filling density of the wood material is formed so as to gradually decrease from one surface to the other surface.
Next, in the wood molded body according to the second invention, in the first invention, the packing density of the wood material continuously decreases from one surface to the other surface in the thickness direction of the wood molded body. It is formed.
Next, in the wood molded body according to the third invention, in the first invention, the packing density of the wood material gradually decreases from one surface to the other surface in the thickness direction of the wood molded body. It is formed.

  Next, a method for manufacturing a wooden molded body according to the fourth invention is a method for manufacturing a wooden molded body according to the first invention, in which the subdivided wooden materials are assembled and a thermosetting resin is added to the mat. A wooden mat making process and a heating press process in which both sides of the wooden mat are heated and pressed. In the heating press process, one surface of the wooden mat is heated at a temperature equal to or higher than the curing temperature of the thermosetting resin. In addition, the other surface of the wood mat is heated at a temperature lower than the curing temperature of the thermosetting resin.

  Next, the manufacturing method of the wooden molded body according to the fifth invention is the manufacturing method of the wooden molded body according to the fourth invention, wherein the wooden mats having different colors are stacked in the wooden mat forming step. It is characterized by creating a mat.

  Next, the floor material or wall material according to the sixth invention is a floor material or wall material using the wood molded body according to any of the first invention to the third invention.

According to the present invention described above, the following effects can be obtained.
First, according to any one of the inventions from the first invention to the third invention, the woody molded body is constituted by the subdivided woody material and the thermosetting resin that bonds the woody materials, The strength of the molded body can be improved. Further, since the surface has a low density, it can be easily removed by means such as shaving the surface of the wood molded body that has become dirty or damaged. Furthermore, by gradually changing the packing density of the wooden material, the cushioning property (impact resistance), soundproofing, maintenance performance and walking feeling of the wooden molded body can be changed according to the packing density of the wooden material. .
Next, according to the fourth invention, in the heating press step, one surface of the wooden mat is heated at a temperature equal to or higher than the curing temperature of the thermosetting resin, and the other surface of the wooden mat is less than the curing temperature of the thermosetting resin. The wood molded body according to the first invention can be manufactured by heating at a temperature of. Moreover, the wood molding which concerns on 1st invention can be manufactured, without cooling after a heat press process, using the characteristic that the thermosetting resin once hardened does not soften even if it heats. Moreover, since the cooling process after a hot press becomes unnecessary, it has the advantage that a production tact is short.
Next, according to 5th invention, the wooden molded object of the state in which the wooden material from which a color differs was piled up in the thickness direction of a wooden molded object can be manufactured. For this reason, the degree of density (degree of hardness or softness) of the wooden molded body can be judged from its appearance.
Next, according to the sixth invention, a floor material or wall material having the characteristics of the woody molded product of any one of the first invention to the third invention is obtained. Therefore, for example, by removing from the surface in accordance with the growth of the infant, it is possible to change from a wooden floor material having excellent safety performance to a wooden floor material having excellent walking performance and maintenance performance. In other words, a wooden flooring suitable for human growth can be provided as appropriate.

The best mode for carrying out the present invention will be described below with reference to the drawings.
1 is a cross-sectional view of a first embodiment using a chip-like wood material, FIG. 2 is a cross-sectional view of a second embodiment using a chip-like wood material, and FIG. 3 is a fiber-like wood material. FIG. 4 is a cross-sectional view of a first embodiment using a material, and FIG. 4 is a cross-sectional view of a second embodiment using a fiber-like woody material. The shades of colors in the drawings represent the color differences. The various wood materials in each figure schematically represent their filling state and shape. For convenience, only one of the wood materials (chip-like wood material 5, fiber-like wood material 6) is numbered.
1-4 is used as an indoor wood floor or the like, and is usually formed in a square plate shape. And it is mounted in the mounting surface in the state of FIGS.

[First embodiment]
The main constituent material of the wood molded body is a fragmented wood material (hereinafter referred to as wood material). The wood materials are bonded with a thermosetting resin. Furthermore, the packing density of the wood material is continuously increased in the thickness direction of the wood molded body (from top to bottom as viewed in FIGS. 1 and 3). That is, the degree of compression of the wood material is small above that, and it is close to the density state that the wood material has in the natural state. The degree of compression of the wood material increases from the top of the wood molded body to the bottom, and the packing density of the wood material in the wood molded body increases. This change in the packing density of the wood material basically occurs continuously without a break.
1 is an example in which a chip-like wood material 5 is used as a constituent material. 3 is an example in which a wood material 6 in the form of fiber (fiber) is used as a constituent material. For convenience of explanation, it is divided into three layers in the thickness direction of the wooden molded body as shown in FIG. 1 and FIG. 3, and the low density layer 1a (3a), medium density layer 1b (3b), and high density layer 1c ( 3c). In addition, the term “density” means the packing density per unit volume of the wood material.
Further, the wooden molded bodies 1 and 3 are colored differently for each of the above-mentioned layers of the wooden molded body.

According to the wood molded bodies 1 and 3 according to the first embodiment, the wood materials are bonded to each other with a thermosetting resin, so that the strength is higher than that using a conventional thermoplastic resin. improves. This is because the thermosetting resin portion enters the concave portion of the wood material in a cured state, and has a strong anchoring effect because it is three-dimensionally bonded to each other and cured in an insoluble and infusible state. Further, the thermosetting resin that has entered the concave portion is combined with the thermosetting resin in a network structure around the concave portion. That is, the thermosetting resin that has entered the concave portion is supported by the entire thermosetting resin having a network structure. As a result, the wood materials are firmly bonded to each other. For this reason, the wooden molded bodies 1 and 3 have sufficient strength to be used for, for example, a floor material for supporting furniture or the like or a wall material for holding a house structure.
According to the wooden molded bodies 1 and 3 according to the first embodiment, the disadvantages of the wooden material are improved. That is, even if the wooden molded bodies 1 and 3 are soiled or damaged, they can be removed by means such as shaving the soiled portion.
Next, in the wooden molded objects 1 and 3 which concern on 1st embodiment, since the space | gap structure of a wooden material is maintained, it can be used as the wooden molded objects 1 and 3 which utilized the characteristic of the wooden material. In other words, the wood molded bodies 1 and 3 have characteristics such as warmness due to low thermal conductivity of the wood material, softness due to elasticity, and humidity adjustment function (humidity control) that absorbs and releases moisture by external humidity. Here, the characteristics of the wood material refer to various properties resulting from the characteristics of the wood material itself such as the void structure of the wood material. For example, it refers to thermal characteristics such as low thermal conductivity, cushioning properties such as elasticity and impact resistance, sound absorption properties that absorb sound, sound insulation properties that block sound, and humidity control (humidity adjustment function).

Further, in the wooden molded bodies 1 and 3 according to the first embodiment, the degree of compression of the wooden material increases from the upper side to the lower side of the wooden molded bodies 1 and 3, and the packing density of the wooden material in the wooden molded bodies 1 and 3 is increased. Becomes larger. For convenience of explanation, the description will be divided into three layers (layer structure) of a low density layer 1a (3a), a medium density layer 1b (3b), and a high density layer 1c (3c) in the thickness direction.
In the low density layer 1a (3a) and the medium density layer 1b (3b), the degree of compression of the wood material is small, so that the void structure itself of the wood material is maintained in a state close to the natural state. For this reason, the effect (sound absorption) which absorbs the sound which the woody material of a natural state has is maintained. Further, in the high-density layer 1c (3c), since the degree of compression of the wood material is large, the void structure itself of the wood material is smaller than that in the natural state. In addition, the wood materials are densely assembled. For this reason, the high density layer 1c (3c) loses elasticity compared to other layers, and has a hardness close to that of dry wood. Therefore, the high-density layer 1c (3c) exhibits an effect (sound insulation) of reflecting and blocking sound. For this reason, compared with the conventional flooring etc. which do not have a layer structure, it becomes the wooden molded object 1 and 3 excellent in the soundproof performance which has the above-mentioned two effects.

Further, in the low density layer 1a (3a) and the medium density layer 1b (3b) in which the wood material is not compressed as compared with the high density layer 1c (3c), it is easy to deform the wood material itself while maintaining the void structure. It is. For this reason, the wood material itself can be greatly bent. Further, by arranging the high-density layer 1c (3c) under the low-density layer 1a (3a) and the medium-density layer 1b (3b), the low-density layer 1a (3a) and medium-density generated when a load is applied. The downward deformation of the layer 1b (3b) is suppressed. Due to this downward deformation suppression, the bent state of the low-density layer 1a (3a) and the medium-density layer 1b (3b) is stabilized, and the wood molded bodies 1 and 3 are more excellent in cushioning properties (impact resistance).
Then, as the low density layer 1a (3a) shifts to the medium density layer 1b (3b) and the high density layer 1c (3c), the surfaces of the wood molded bodies 1 and 3 become harder. As the surfaces of the wooden molded bodies 1 and 3 become harder, the stability of the feet when a person walks improves. For this reason, what is called a walk feeling improves. Furthermore, the surfaces of the wooden molded bodies 1 and 3 become dense by densely gathering the wooden materials. For this reason, the maintainability of the wooden molded bodies 1 and 3 is improved. In other words, dust and dust do not collect in the gaps between the wood materials, making it easier to clean. Since the surfaces of the wooden molded bodies 1 and 3 are also smooth, the appearance is also improved.
That is, the wooden molded bodies 1 and 3 according to the first embodiment change their cushioning properties (impact resistance), soundproofing properties, maintenance properties, and their walking feeling by changing the packing density of the wooden material. be able to.

Since the wooden molded bodies 1 and 3 according to the first embodiment have high strength, they can be used as a wooden flooring or the like for many years until an infant grows up to an adult. In addition, it becomes a wooden flooring that makes use of the characteristics of the wooden material.
Furthermore, since the wooden molded bodies 1 and 3 have a layer structure, they become a wooden floor material or the like that exhibits various effects. That is, in the human childhood, the low density layer 1a (3a) such as the wooden flooring is located on the surface of the wooden flooring. For this reason, the cushioning property (impact resistance) of the low-density layer 1a (3a) has higher safety performance for infants than other layers. In addition, the soundproofing effect that has both sound absorption and sound insulation properties reduces or prevents the sound from leaking to the outside even if the infant cries or rampages.
Further, the wooden flooring or the like can be removed by shaving the surface layer portion. For this reason, the surface of the wooden flooring or the like can be hardened from the low density layer 1a (3a) to the medium density layer 1b (3b) and the high density layer 1c (3c) in accordance with human growth. As the surface of the wooden floor becomes harder, its walking feeling and maintainability improve. For this reason, as infants grow up into adolescents and adults, it changes from safety performance to wooden flooring with excellent walking performance and maintenance performance. That is, it is possible to appropriately provide a wooden floor material suitable for human growth.

Furthermore, by applying different coloring to each layer, the color and pattern of the wooden flooring and the like change each time. For this reason, the degree of density (degree of hardness or softness) of the wooden flooring can be judged from its appearance. In addition, the appearance of wooden flooring can be changed as people grow.
In addition, a well-known colorant, dye, a pigment, etc. are used for the colorant which colors a woody material.

Incidentally density of the low density layer 1a (3a) ^is desirably ^{0.2g / cm 3 ~0.4g / cm 3} . If the density of the low density layer 1a (3a) is less than 0.2 g / cm ³ , strength as a wooden flooring cannot be obtained, and the density of the low density layer 1a (3a) is higher than 0.4 g / cm ^3. And cushioning (impact resistance) sufficient to ensure safety for infants cannot be obtained. More ^preferably, it is ^{0.25g / cm 3 ~0.35g / cm 3} . If the density of the low-density layer 1a (3a) is within this range, sufficient cushioning properties can be obtained to ensure the strength as a wooden flooring and the like and to ensure safety for an infant.
Density of medium density layer 1b (3b) also ^is desirably ^{0.4g / cm 3 ~0.6g / cm 3} . If the density of the medium density layer 1b (3b) is less than 0.4 g / cm ³ , the feet become unstable when a child (especially a kindergarten or elementary school student) walks. More desirably, it is 0.45 g / cm ^{3 to} 0.65 g / cm ³ . When the density of the medium density layer 1b (3b) is within this range, the feet are not unstable when a child (especially a kindergarten or elementary school student) walks, and the maintainability is good.
The density of the high density layer 1c (3c) ^is preferably a ^{0.6g / cm 3 ~0.8g / cm 3} . If the density of the high-density layer 1c (3c) is less than 0.6 g / cm ³ , a sound insulation effect cannot be obtained, and if the density of the high-density layer 1c (3c) is higher than 0.8 g / cm ³ , walking feeling is poor. Become. More preferably is ^{0.65g / cm 3 ~0.75g / cm 3} . If the density of the high-density layer 1c (3c) is in this range, it has a sound insulation effect and stability during walking is ensured, and the walking feeling is good.

(Subdivided wood material)
The subdivided woody material is a woody material derived from woody or herbaceous materials formed into chips, fibers (fibers), powders, granules or flakes. Here, a woody molded body 1 using a chip-like woody material as its constituent material is preferable. Since the chip-like wood material has many uneven shapes, the number of joints between the wood material and the thermosetting resin increases. In addition, the wood-like molded body 3 is preferably used in which the wood-like material in the form of fiber (fiber) is obtained by interlacing the wood-like materials and entwining each other as a constituent material. The entangled fiber materials are difficult to unravel. Further, the wood molded body may be one using a wood material of one type of shape as a constituent material. A plurality of types of wood materials may be mixed. For example, a wooden molded body using a small-sized wood material such as granular or powder is compressed into a denser state than a wood material using a chip-like wood material.
The woody material derived from woods includes, for example, wood and bark collected from each tree such as conifers, broadleaf trees, and tropical trees. Examples of the woody material derived from herbs include various kinds of plants such as coconut shell, zai monkey, rice, jute, kenaf, and bast plants are often used. Moreover, the woody material derived from herbs may be appropriately subjected to chemical treatment such as sugarcane bagasse and pulp.
The wood material may contain a known reinforcing material or preservative as necessary.

(Thermosetting resin)
The thermosetting resin may be a known thermosetting resin capable of maintaining the shape of the wooden molded bodies 1 and 3 by bonding the compressed woody materials to each other. As the thermosetting resin, for example, phenol resin, epoxy resin, unsaturated polyester resin, urea resin, melamine resin, polyurethane resin, silicon resin and the like are used. One type of these thermosetting resins may be used, or a plurality of types of thermosetting resins may be mixed. Among the above-mentioned thermosetting resins, wood moldings 1 and 3 in which a phenol resin (resole) having a high bonding strength for bonding wood materials to each other as compared with other thermosetting resins is used. The wooden molded bodies 1 and 3 in which a phenol resin (resole type) is used have higher strength than those using other thermosetting resins. Further, since no curing agent is required for curing the phenol resin (resole type), no bad odor caused by the curing agent is generated in the wooden molded bodies 1 and 3.

[Second Embodiment]
The main component of the wooden molded body according to the second embodiment is a subdivided wooden material, and the wooden materials are bonded with a thermosetting resin. That is, the basic configuration is the same as that of the first embodiment. Therefore, detailed description of the same configuration as that of the first embodiment is omitted. In addition, the wooden molded object 2 which concerns on 1st embodiment of FIG. 2 uses the chip-shaped wooden material as the main component material. Further, the wood molded body 4 in FIG. 4 uses a fiber-like wood material as its main constituent material.
The difference of the second embodiment from the first embodiment is that the packing density of the wood material is increased stepwise as shown in FIGS. That is, the wooden molded bodies 2 and 4 are configured by sequentially stacking wooden molded layer bodies having different densities in the thickness direction of the wooden molded bodies 2 and 4. The number and density of the wood molding layered body are appropriately set. In the second embodiment, as shown in FIG. 2, three wooden molding layers having different densities are stacked in the thickness direction of the wooden moldings 2 and 4 (from top to bottom as viewed in FIGS. 2 and 4). That is, the low-density layer body 2a (4a), the medium-density layer body 2b (4b), and the high-density layer body 2c (4c) are stacked in that order from above. Moreover, different coloring is made for each layer.
Further, the respective wooden molded layer bodies are usually bonded to each other by a known means. For example, they are bonded by an adhesive such as a thermosetting resin or a thermoplastic resin, or a physical means such as a nail, a bolt and a nut. Also when bonding each wood molding layer body with an adhesive agent, it is desirable to use the thermosetting resin whose bond strength is higher than a thermoplastic resin.
Also in the second embodiment, the same operation and effect as in the first embodiment can be obtained. In addition, when the wood molding layer bodies are bonded to each other by physical means, the wood molding layer bodies can be removed simply by removing the physical means, so that the replacement becomes easy.

  In addition to the thermosetting resin, a known adhesive is used for the low-density layer body 2a (4a), which does not require strength compared to the medium-density layer body 2b (4b) and the high-density layer body 2c (4c). May be used. For example, synthetic polymers other than natural polymers, semi-synthetic polymers, and thermosetting resins may be used. Examples of natural polymers include polysaccharides such as starch paste, fats and oils such as pine sprout, and proteins such as trimochi and glue. Semi-synthetic polymers include cellulose, cellulose ether, cellulose ester and the like. Synthetic polymers other than thermosetting resins include thermoplastic resins and rubber polymers. Moreover, only one type of the above-mentioned adhesive may be used, or a plurality of types of adhesives may be mixed.

[Production method]
The manufacturing method according to the present embodiment will be described below with reference to FIGS.
The manufacturing method according to the present example is a method for manufacturing a wooden molded body according to the first embodiment, and includes a wooden mat creation step and a heating press step. The wood material used in the wood mat preparation step is appropriately colored. In addition, in the manufacturing method which concerns on FIGS. 5-7, the wooden material of the chip shape colored as FIG. 5 is used as a raw material. Moreover, a liquid phenol resin (resole type) is used as a thermosetting resin.
(Wood material coloring process)
In the coloring process of the wooden material, a coloring process is performed in which the above-described wooden material is colored or dyed using a known colorant or dyeing agent. And in the assembly process described later, the colored woody material is stacked for each color.

(Wood mat making process)
In principle, the wood mat production process includes an assembling process for assembling wood materials and a process for applying a thermosetting resin to the assembled wood materials. The produced wood mat 10 is in a state where chip-like wood materials are evenly laminated in the thickness direction of the wood mat 10 as shown in FIG.
First, in the assembly step, the colored wood material is laminated by a known lamination means. For example, a known fiber laminating method such as card, fleece or airlay is used.
In the case of fiber (fiber) -like wood materials, it is desirable that the fiber (fiber) -like wood materials are entangled with each other by a general-purpose method to form a dense state. Since a plurality of fiber (fiber) -like wood materials are intertwined with one fiber (fiber) -like wood material, the fiber (fiber) -like wood material is difficult to unravel. For this reason, the intensity | strength of the wooden molded object 1 manufactured improves. For example, a known confounding method such as needle punch, stitch bond, or the like is used.

Next, the above-mentioned thermosetting resin is applied to the assembled woody material by a known method. For example, a solid thermosetting resin such as a sheet, plate, powder, or granule is mixed with the wood material. Further, a dispersion solution in which a thermosetting resin is dispersed in a predetermined solvent is applied to a wooden material assembled by a known application method such as spraying or roller. A known curing agent may be added to the thermosetting resin.
As the thermosetting resin, the above-described various thermosetting resins can be used.
For example, a liquid or powdery phenol resin (resole type) can be used. This liquid, powdery phenol resin (resole type) has a phenol / formaldehyde molar ratio of 1 / 1.0 to 4.0 in the presence of an alkali catalyst (sodium hydroxide, potassium hydroxide, etc.). And obtained by reacting phenol with formaldehyde. At this time, it is preferable to use a liquid or powdery phenol resin (resole type) having a free phenol content of less than 5% by weight and a free formaldehyde content of less than 0.7% by weight. Thus, if the phenol resin (resole type | system | group) with little free formaldehyde content is used, the amount of formaldehyde emission from the manufactured wooden molded object 1 can be restrained low. For this reason, the user does not feel uncomfortable. In particular, deterioration of infant health can be prevented. When the free phenol resin content is 5% by weight or more or the free formaldehyde content is 1% by weight or more, the phenol resin (resole) is treated as a poisonous or deleterious substance. That is, the handling becomes difficult. In addition, if the free formaldehyde content is 0.7% by weight or more, the odor of formaldehyde increases in the produced wooden molded body 1.

  Here, it is desirable that the thermosetting resin is uniformly applied to the entire aggregated wood material. This is because the wood molded body 1 has no deviation in the adhesiveness between the wood materials. That is, a weak strength part does not occur in a part of the wooden molded body 1, and uniform strength can be ensured in the entire wooden molded body 1. As a method for uniformly applying the thermosetting resin, for example, a spray solution, an aerosol, or the like is used to apply the dispersion solution of the thermosetting resin to the aggregated wood material. By making the dispersion solution of the thermosetting resin into fine particles by spraying or the like, the thermosetting resin can be uniformly supplied to the aggregated woody material. Moreover, after mixing a powdery and granular thermosetting resin uniformly with a wooden material, it can also laminate | stack in that state. Considering the time for removing the solvent contained in the dispersion solution, it is preferable to use a solid thermosetting resin because the time required for the production process can be shortened.

The thermosetting resin is added in such an amount that the wooden materials compressed in the heating press process described later are bonded together and held in an aggregated state.
For example, when the wood material is in a chip shape, the thermosetting resin is applied to the wood mat so that the ratio of the thermosetting resin is 10% by weight with respect to the total weight of the wood mat 10. When the weight ratio of the thermosetting resin is increased, the weight of the wooden molded body 1 is increased. On the other hand, when the weight ratio of the thermosetting resin is lowered, the strength of the woody molded body 1 may be reduced. Desirably, the ratio is 3 to 10% by weight. If it is in this range, the strength required for the wooden flooring or the like can be secured without increasing the weight of the wooden molded body 1.
When the wood material is in a fiber form, the thermosetting resin is applied to the wood mat 10 so that the weight ratio of the wood material to the thermosetting resin is 70:30. When the weight ratio of the thermosetting resin is increased, the weight of the woody molded body is increased. On the other hand, if the weight ratio of the thermosetting resin is lowered, the strength of the woody molded body may be lowered. Desirably, the weight ratio of the wood material to the thermosetting resin is 95: 5 to 70:30. If it is in this range, the strength required for the wooden flooring or the like can be ensured without increasing the weight of the wooden molded body.

(Hot press process)
Next, the wooden mat 10 is heated and compressed by a general-purpose method. As the heating means, far infrared heat, microwave heat, a heating roller or the like can be used. As shown in FIG. 6, the heating apparatus of the manufacturing method according to the present embodiment includes a pair of flat plate upper surface press die 7 and lower surface press die 8. General-purpose heating means are attached to the upper surface press die 7 and the lower surface press die 8. The upper surface press die 7 and the lower surface press die 8 are heated and compressed while sandwiching the wood mat 10. That is, as shown in FIG. 6, the heating press is performed in such a manner that the wood mat 10 is sandwiched between the upper surface press die 7 from above and the lower surface press die 8 from below.

At this time, one surface of the wooden mat 10 is heated at a temperature equal to or higher than the curing temperature of the thermosetting resin. Then, the other surface of the wooden mat 10 is heated at a temperature lower than the curing temperature of the thermosetting resin.
For example, in the case of the wood mat 10 to which a liquid phenol resin is applied, the heating temperature of the lower surface press die 8 is desirably 180 ° C. to 230 ° C. If the heating temperature of the lower surface press die 8 is higher than 230 ° C., the wood mat 10 may be burnt. If the heating temperature of the lower surface press die 8 is lower than 180 ° C., the time for the heating press process becomes longer. More preferably, the heating temperature of the bottom press die 8 is 200 ° C to 230 ° C. On the other hand, the heating temperature of the upper surface press die 7 is desirably 80 ° C to 150 ° C. When the heating temperature of the upper surface press die 7 is higher than 150 ° C., a density difference hardly occurs in the thickness direction of the woody molded body 1. Moreover, when the heating temperature of the upper surface press die 7 is lower than 80 ° C., the time for the heating press process becomes longer. More preferably, the heating temperature of the upper surface press die 7 is 100 ° C to 150 ° C.
The heating temperature of the lower surface press die 8 (upper surface press die 7) is the surface temperature of the lower surface press die 8 (upper surface press die 7).

At this time, it is desirable that the difference between the heating temperature of the upper surface press die 7 and the heating temperature of the lower surface press die 8 is larger. This is because if the difference between the two heating temperatures is large, the density difference inside the woody molded body 1 can be clarified.
Preferably, the difference between the heating temperature of the upper surface press die 7 and the heating temperature of the lower surface press die 8 is 30 ° C to 100 ° C. When this temperature difference is present, a density difference in the thickness direction of the wood molded body 1 can be easily provided.

In the hot press process, the wooden mat 10 is heated and compressed until a predetermined density difference occurs in the wooden mat 10 and the thermosetting resin is sufficiently cured.
For example, when using a liquid phenol resin (resole type) under the above-described conditions, it is desirable to maintain the heated and pressurized state for 10 to 30 minutes. If the heating and pressurizing time is shorter than 10 minutes, the curing of the resin is not completed. Moreover, if it heats and pressurizes longer than 30 minutes, a wooden material will burn and the intensity | strength of the manufactured wooden molded object 1 will become low.

Next, the effect of the manufacturing method according to the present embodiment will be described.
First, according to the manufacturing method which concerns on a present Example, the wooden molded object 1 which concerns on 1st embodiment can be manufactured. This is because the Young's modulus of the wood material changes according to the heating temperature. That is, in the manufacturing method according to the present embodiment, pressure is uniformly applied in the thickness direction of the wooden mat 10. At this time, the wooden material heated at a temperature equal to or higher than the curing temperature of the thermosetting resin has a Young's modulus smaller than that of the wooden material heated at a temperature lower than the curing temperature. . Moreover, in the heating press process in FIG. 6, the heating temperature becomes high toward the downward direction from the upper direction of the wooden mat 10 (temperature gradient arises). This temperature gradient is continuously generated in the thickness direction of the wood mat 10 without a break. For this reason, the Young's modulus of the wooden material decreases from the upper direction to the lower direction of the wooden mat 10. The lower the Young's modulus, the greater the degree of compression. Thus, as shown in FIG. 7, the woody material according to the first embodiment in which the packing density of the woody material is continuously increased in the thickness direction of the woody molded body 1 (from the top to the bottom as viewed in FIG. 7). The molded object 1 can be manufactured.
In addition, using the property that once cured thermosetting resin does not soften even when heated, the wood molded body according to the first embodiment without performing a cooling step for maintaining its shape after the heating press step 1 can be manufactured. For this reason, a manufacturing process can be shortened.
Furthermore, the wooden molded body 1 in a state where wooden materials having different colors are stacked in the thickness direction of the wooden molded body 1 can be manufactured by the coloring process of the wooden material. For this reason, the degree of density (degree of hardness or softness) of the wooden molded body 1 can be determined from its appearance.

(Example)
Hereinafter, the present invention will be described based on examples. In addition, this invention is not limited to a following example.
First, the manufacturing method of the wooden molded object 1 which concerns on an Example is demonstrated.
(Wood mat making process) First, wood materials gathered by laminating chip-like wood materials obtained from kenaf bast by the airlay method were made.
Next, liquid phenolic resin (resole type) was spray-applied from the surface of the gathered wood material to create a wood mat 10. At this time, the density of the wood mat 10 is 0.2 g / cm ³ uniformly in the thickness direction.
Next, a liquid phenol resin (resole type) was applied so that the ratio of the thermosetting resin to the total weight of the wooden mat 10 was 10% by weight. The liquid phenol resin (resole type) in this example has a phenol resin content of 50 to 55% by weight, a free phenol content of 4.2% by weight, and a free formaldehyde content of 0% with respect to the weight of the total solution. .6% by weight. The solvent is water.
(Heat-pressing process) Next, the wooden molded body 1 was manufactured by heating and compressing the wooden mat 10 using the hot press method under the following conditions. The heating temperature of the upper surface press die 7 is 150 ° C., and the pressing temperature of the lower surface press die 8 is 200 ° C. The heating press time is 30 minutes, and the press pressure is 11 kgf / cm ² .

(Density measurement method for wood moldings)
First, a wood molded body to be measured is prepared. Next, γ rays having a predetermined radiation dose (GBq) are continuously irradiated in the thickness direction of the woody molded body. At this time, the radiation dose (GBq) of gamma rays after passing through the woody molded body is measured and recorded. Next, the transmission loss amount (GBq) of γ rays is calculated by subtracting the radiation amount (GBq) after having passed through the wooden molded body from the initial radiation amount (GBq). Next, the same operation is performed on the resin plate (standard sample) whose density has already been specified, and the transmission loss rate (GBq) of γ rays is calculated. Next, the transmission loss amount (GBq) of the wooden molded body and the transmission loss amount (GBq) of the standard sample are compared and calculated by known means, and the density (g / cm ³ ) of the wooden molded body is calculated.
In this measurement test, the source of γ-ray radiation was americium (Am) 241. The radiation dose is 3.7 GBq. As a standard sample, a resin plate having a density of 1 g / cm ³ was used.

Table 1 is a table of the density at a specific portion of each layer of the example (woody molded body 1). FIG. 8 is a diagram showing a change in density in the thickness direction of the wooden molded body 1. That is, Table 1 shows the respective densities in the density measurement portions 20, 21, and 22 in FIGS. The density measurement site 20 is a site located in the low density layer of the woody molded body 1. The density measurement site 21 is a site located in the medium density layer of the woody molded body 1. The density measurement part 22 is a part located in the high-density layer of the woody molded body 1.
According to Table 1, it can be seen that the density of the wooden molded body 1 increases in the order of the density measurement parts 20, 21, and 22 of the wooden molded body 1. That is, the density of the wood molded body 1 increases in the order of the low density layer 1a, the medium density layer 1b, and the high density layer 1c.
Further, according to FIG. 8, it can be seen that the density is continuously increased in the thickness direction of the back side (from the top to the bottom in FIG. 7) of the wood molded body 1.

In addition, this invention is not limited to said embodiment. That is, the wooden molded body according to the present invention can be applied not only to a wooden floor material, but also to various wooden products having a part touched by a person such as a ceiling material and a constituent material of furniture.
Further, in the method for producing a wooden molded body, the method comprises: a wooden mat creating step for gathering subdivided wooden materials and adding a thermosetting resin to create a mat; and a pressing step for pressing both sides of the wooden mat. In the heating and pressing step, only one surface of the wood mat can be heated using a heating means at a temperature equal to or higher than the curing temperature of the thermosetting resin.
According to this, only one surface of the wood mat is heated using the heating means at a temperature equal to or higher than the curing temperature of the thermosetting resin in the heating press process, thereby producing a density difference continuously in the thickness direction. A fiber molded body can be manufactured. In addition, since the other surface of the wooden mat is not heated by the heating means, a decrease in the Young's modulus of the wooden material located near the other surface of the wooden mat due to heating can be suppressed. That is, compared with the case where it heats from both surfaces of a wooden mat, the compression degree of the wooden material located in the other surface side vicinity of a wooden mat can be restrained small.

It is sectional drawing of 1st embodiment using a chip-shaped woody material. It is sectional drawing of 2nd embodiment using the wood material of a chip shape. It is sectional drawing of 1st embodiment using the woody material of fiber (fiber). It is sectional drawing of 2nd embodiment using the woody material of fiber (fiber). It is sectional drawing of the wood mat using the chip-like wood material. It is sectional drawing of the wooden mat at the time of a heating press process. It is sectional drawing of the wooden mat of a wooden molded object. It is a figure showing the change of the density in the thickness direction of the wooden molded object 1. FIG.

Explanation of symbols

1, 2, 3, 4 Wood compacts 1a, 3a Low density layers 1b, 3b Medium density layers 1c, 3c High density layers 2a, 4a Low density layer bodies 2b, 4b Medium density layer bodies 2c, 4c High density layer bodies 5 Chip-like wood material 6 Fiber-like wood material 7 Upper surface pressing die 8 Lower surface pressing die 10 Wood mat 20, 21, 22 Density measurement site

Claims (6)

A wood molded body having a predetermined thickness,
It consists of a subdivided wood material and a thermosetting resin that binds the wood materials,
A wood molded body, characterized in that it is formed so that the packing density of the wood material gradually decreases from one surface to the other surface in the thickness direction of the wood molded body. In the wooden molded object of Claim 1,
A wooden molded body, wherein the wooden molded body is formed such that the packing density of the wooden material continuously decreases from one surface to the other surface in the thickness direction of the wooden molded body. In the wooden molded object of Claim 1,
A wood molded body, wherein the wood material is formed so that the packing density of the wood material gradually decreases from one surface to the other surface in the thickness direction of the wood molded body. A method for producing a woody molded article according to claim 1,
It consists of a wooden mat creating process for gathering the subdivided wooden materials and adding a thermosetting resin to create a mat, and a heating press process for heating and pressing both sides of the wooden mat,
While heating one side of the wood mat in the heating press step at a temperature equal to or higher than the curing temperature of the thermosetting resin,
A method for producing a wood molded article, comprising heating the other surface of the wood mat at a temperature lower than the curing temperature of the thermosetting resin. In the manufacturing method of the wooden molded object of Claim 4,
During the wood mat making process,
A method for producing a wood molded body, wherein the wood mat is produced by stacking the wood materials having different colors. The flooring or wall material using the wooden molded object in any one of Claims 1-3.