JP2022119673A - Woody base material, decorative material and manufacturing method thereof - Google Patents

Abstract

To provide a woody base material free from a harmful substance that might act as a potential cause of a sick house syndrome, and having practical water proofness, a decorative material equipped with the woody base material and a manufacturing method of the woody base material.SOLUTION: A woody base material 10 includes: a woody material 4 having at least one of forms of powder and chip; and a thermoplastic resin composition 5. A standardization C-H area calculated using an expression (1) from an absorption spectrum obtained at a Fourier-type infrared spectroscopic measurement is within a range of 0.07 to 1.00: A standardization C-H area=SC-H/(SO-H+SC-OH) ... (1). In the expression (1), SC-H is a peak area value derived from a CH2 group and a CH3 group, SO-H is a peak area value derived from an OH group and SC-OH is a peak area value derived from a C-OH group, respectively.SELECTED DRAWING: Figure 1

Description

The present invention relates to a wooden base material, a decorative material, and a method for producing a wooden base material.

The wood base material is a base material obtained by heating and pressurizing a mixture of a wood material such as wood flour, wood chips, and wood fiber with an adhesive. This wooden base material is called particle board or medium density fiberboard depending on the type of wood material, and is used in a wide range of applications such as base material for floors and walls, fittings and furniture.

Conventionally, urea resin-based adhesives, melamine resin-based adhesives, or phenolic resin-based adhesives have been used as adhesives for wooden substrates together with curing agents containing formaldehyde. Since formaldehyde is a harmful substance that causes sick building syndrome, its emission from wooden substrates is a problem, and various measures for reducing the amount of emission are being studied. However, in the prior art, it was difficult to completely suppress the diffusion of formaldehyde.

On the other hand, conventionally, as an adhesive that does not contain formaldehyde, an adhesive mainly composed of powdered sugar and powdered polycarboxylic acid is used. A method for manufacturing a fiber board has been proposed (see paragraph [0017] of Patent Document 1). As a formaldehyde-free adhesive, conventionally, a method for producing a laminate containing a wooden substrate using an adhesive made of polyvinyl alcohol and water has been proposed (Patent Document 2, paragraph [0015], and See Figure 1).

JP 2016-55620 A Japanese Patent No. 5553279

However, wood base materials using the above-described conventional adhesives are not practically sufficient in mechanical properties such as bending strength and water resistance.
Accordingly, the present invention provides a wooden base material that does not contain harmful substances that cause sick house syndrome and has practical water resistance, a decorative material that includes the wooden base material, and a method for producing the wooden base material. The challenge is to

A wood base material according to an aspect of the present invention includes a wood material having at least one of a powdery shape and a chip shape, and a thermoplastic resin composition, and is characterized by Fourier infrared spectroscopy. It is characterized in that the normalized CH area calculated using the following formula (1) from the absorption spectrum obtained in the measurement is within the range of 0.07 or more and 1.00 or less.
Normalized C-H area = S _C-H / (S _O-H + S _C-OH ) Formula (1)

Here, in formula (1), S _C-H is the area value of the peaks derived from CH ₂ group and CH ₃ group at wave numbers around 2700 to 3000 cm ⁻¹ , and S _O-H is the peak area value at wave numbers around 3000 to 3500 cm ⁻¹ The area value of the peak derived from the OH group, S _C-OH , indicates the area value of the peak derived from the C-OH group near the wave number of 900 to 1200 cm ^-1 .

Further, the wooden base material according to one aspect of the present invention is characterized in that the normalized CH area is in the range of 0.08 or more and 0.35 or less.
Further, in the wood base material according to one aspect of the present invention, the mass ratio of the wood material and the thermoplastic resin composition (wood material/thermoplastic resin composition) is within the range of 95/5 to 70/30. characterized by being

Further, in the wood base material according to one aspect of the present invention, the mass ratio of the wood material and the thermoplastic resin composition (wood material/thermoplastic resin composition) is in the range of 85/15 to 70/30. characterized by being
Moreover, the wooden base material according to one aspect of the present invention is characterized in that the wooden material contains a fungal bed as a raw material.

Moreover, the wooden base material according to one aspect of the present invention is characterized in that the thermoplastic resin composition contains polyethylene.
Moreover, the wooden base material according to one aspect of the present invention is characterized in that the thermoplastic resin composition contains an acid-modified polyolefin.
Further, in the wooden base material according to one aspect of the present invention, the content of the acid-modified polyolefin is within the range of 3 parts by mass or more and 40 parts by mass or less with respect to 100 parts by mass of the total thermoplastic resin composition. Characterized by

A decorative material according to an aspect of the present invention is characterized in that a designable base material is laminated on the woody base material described above.

A method for producing a woody base material according to an aspect of the present invention includes heating a raw material mixture containing a woody material having at least one of powdery and chip-like shapes and a powdery thermoplastic resin composition. A step of pressing to form a wooden substrate, wherein the wooden substrate has a normalized CH area calculated using the following formula (1) from an absorption spectrum obtained in Fourier infrared spectroscopy. is in the range of 0.07 to 1.00.
Normalized C-H area = S _C-H / (S _O-H + S _C-OH ) Formula (1)

Here, in formula (1), S _C-H is the area value of the peaks derived from CH ₂ group and CH ₃ group at wave numbers around 2700 to 3000 cm ⁻¹ , and S _O-H is the peak area value at wave numbers around 3000 to 3500 cm ⁻¹ The area value of the peak derived from the OH group, S _C-OH , indicates the area value of the peak derived from the C-OH group near the wave number of 900 to 1200 cm ^-1 .

Further, in the method for producing a wood base material according to one aspect of the present invention, the step of producing the powdery thermoplastic resin composition includes kneading a plurality of types of thermoplastic resin compositions by an extrusion method. and pulverizing the kneaded thermoplastic resin composition into powder.

According to one aspect of the present invention, a wooden base material that does not contain harmful substances that cause sick house syndrome and has practical water resistance, a decorative material that includes the wooden base material, and a method for producing the wooden base material. can provide

It is a schematic diagram which shows the manufacturing method of the wooden base material which concerns on embodiment of this invention. 1 is a schematic cross-sectional view showing the structure of a wooden base material according to a first embodiment of the present invention; FIG. Infrared absorption spectra of common wood materials. 4 is an infrared absorption spectrum of the wood base material according to the first embodiment of the present invention; FIG. 5 is a schematic cross-sectional view showing the structure of a decorative material according to a second embodiment of the present invention;

An embodiment of the present invention will be described below with reference to the drawings.
Here, the drawings are schematic, and the relationship between the thickness and the planar dimension, the ratio of the thickness of each layer, and the like are different from the actual ones. Further, the embodiments shown below are examples of configurations for embodying the technical idea of the present invention. It does not specify anything. Various modifications can be made to the technical idea of the present invention within the technical scope defined by the claims.

[First embodiment]
FIG. 1 shows a schematic diagram for explaining a method for producing a wooden base material according to an embodiment of the present invention. A metal plate 2 is laid on the bottom surface of a jig 1 for preparing a wooden base material having an accommodating portion cut out to a predetermined size (for example, a square of 10 cm×10 cm), and a release film 3 is placed thereon.

Next, a raw material mixture 6 containing a wood material 4 having at least one of powdery and chip-like shapes and a powdery thermoplastic resin composition 5 is put into the accommodating portion of the jig 1 for producing a wooden base material. , the release film 3 is placed on the raw material mixture 6 .
Next, the metal plate 7 for adjusting the thickness is placed on the jig 1 for producing the wooden base material, and the raw material mixture 6 is pressed from above with the metal weight 8 via the release film 3 .

Finally, the pressing machine top plate 9 set to predetermined conditions is heated and pressurized from above the raw material mixture 6 via a metal weight 8 to form the wooden base material 10 according to the present embodiment.
FIG. 2 is a schematic cross-sectional view showing the structure of the wooden base material 10 according to this embodiment.
The wooden base material 10 is called a particle board or a medium density fiberboard depending on the type of the wooden material 4, and is used in a wide range of applications such as base materials for floors and walls, fittings, and furniture.

The wooden base material 10 does not contain harmful substances such as formaldehyde that cause sick house syndrome. Therefore, it is possible to suppress the diffusion of harmful substances that cause sick house syndrome, such as formaldehyde, from inside the wooden base material 10 .
The wood material 4 and the thermoplastic resin composition 5 constituting the wood base material 10 will be described below.

(wood material 4)
The wooden material 4 has at least one shape of powder and chips.
Here, there is generally no definition of size and shape for "powder" and "chip". In this embodiment, the size (average particle size) is generally in the range of several tens of microns to several centimeters. In order to stably manufacture the wooden base material 10, it is desirable that the average particle size of the wooden material 4 is within the range of 1 to 5 millimeters.

The wood material 4 includes, for example, wood flour, wood fiber, and wood pulverized into chips, and thinned wood, sawdust, and waste wood, for example, can be used as raw materials.
The wood material 4 can also be candidates other than wood, for example, bamboo, hemp, coconut fiber, walnut shell, etc., as long as they contain a cellulose component like wood.

As a raw material for the wooden material 4, for example, a used mushroom bed that is generated in large quantities during mushroom cultivation is suitable. The mushroom bed is a medium used for mushroom cultivation, and is made by mixing nutrients such as bran and rice bran with wood chips and sawdust. It is estimated that around 300,000 tons of mushroom beds are discarded annually in Japan after mushroom cultivation, and they are promising as biomass, but the current situation is that recycling is not progressing. is beneficial in reducing environmental impact.

As the wooden substrate 10 containing the fungus bed, the fungus bed may be used alone as the wood material 4, or the fungus bed may be used in combination with another wood material 4. Here, the “woody base material containing a fungal bed” means a woody base material 10 in which the ratio of the fungal bed to the volume of the whole woody material 4 is in the range of 1% or more and 100% or less.

(Manufacturing method of wooden material 4)
For example, when trying to obtain the wooden material 4 from waste wood, many foreign substances such as concrete pieces, metal pieces, and papers are included. Foreign matter can be removed by known methods such as magnetic separation, air separation, gravity separation, and the like. In addition, the size of coarse particles is adjusted by a known method such as cutting and crushing, and those in the range of approximately several tens of microns to several centimeters are used. In order to stably manufacture the wooden base material 10, it is desirable that the average particle diameter of the wooden material 4 is in the range of 1 to 5 millimeters.
Furthermore, when the wooden material 4 is to be obtained from the fungal bed, it is preferable to sterilize it by a known method before using it.

(Mass ratio of wooden material 4 and thermoplastic resin composition 5)
The mass ratio of the wooden material 4 and the thermoplastic resin composition 5 (woody material/thermoplastic resin composition) is desirably in the range of 95/5 to 70/30. If the content of the wooden material 4 exceeds the above numerical value (95/5), the wooden base material 10 cannot be provided with sufficient bending strength. On the other hand, if the content of the wooden material 4 is less than the above numerical value (70/30), deformation of the wooden base material 10 tends to occur during heating and pressurization, which is not preferable.

The mass ratio of the wooden material 4 and the thermoplastic resin composition 5 (woody material/thermoplastic resin composition) is more preferably in the range of 85/15 to 70/30. By setting the content of the woody material 4 within the above numerical range, the woody base material 10 having a higher bending strength can be obtained.
The woody base material 10 may be a multiple layer of two or more layers instead of a single layer, and the mass ratio of the woody material 4 and the thermoplastic resin composition 5 may be changed for each layer.

(Thermoplastic resin composition 5)
The thermoplastic resin composition 5 is a powdery composition having an average particle size of several tens of microns to 1 millimeter. As the thermoplastic resin composition 5, various materials such as polyester, polyamide, polyolefin, ethylene-propylene-diene rubber, ethylene vinyl acetate, and silicone rubber can be used. is preferred. The particle size of the thermoplastic resin composition 5 is not particularly limited, but when mixing with the woody material 4, it is preferable that the particle size of the thermoplastic resin composition 5 is about the same because mixing is easy. If the particle size of the thermoplastic resin composition 5 is too small, it will pass through the wood material 4 and deposit on the lower part. Therefore, the particle size (average particle size) of the thermoplastic resin composition 5 is more preferably in the range of 30 microns (μm) or more and 300 microns (μm) or less.

The thermoplastic resin composition 5 may be used alone, or may be used by mixing a plurality of types. From the viewpoint of the mechanical strength of the wooden base material 10, it is desirable that the thermoplastic resin composition 5 contains 50 parts by mass or more and 100 parts by mass or less of polyethylene with respect to 100 parts by mass of the entire thermoplastic resin composition. More preferably, polyethylene is contained within the range of 80 parts by mass or more and 100 parts by mass or less.

The polyethylene added to the thermoplastic resin composition 5 is not particularly limited, and may be high-density polyethylene (polyethylene having a specific gravity of about 0.92 to 0.96), low-density polyethylene (having a specific gravity of 0.91 to 0.96). 92 polyethylene), ultra-low density polyethylene (polyethylene with a specific gravity of less than 0.9), linear low density polyethylene (polyethylene with a specific gravity of less than 0.94), etc. The material is appropriately selected and used in consideration of reactivity during pressurization, fluidity of the raw material mixture 6, and the like. Among the materials described above, it is more desirable to use high-density polyethylene in order to obtain the wooden base material 10 having a high bending strength.

The polyethylene used in this embodiment may be biomass-derived polyethylene. Biomass-derived polyethylene is obtained by polymerizing a monomer containing biomass-derived ethylene. Since biomass-derived ethylene is used as a raw material monomer, the polymerized polyethylene is biomass-derived. The raw material monomer for polyethylene may not contain 100% by mass of biomass-derived ethylene.

Materials to be mixed with the thermoplastic resin composition 5 are not particularly limited, but examples thereof include acid-modified resins and organic peroxides.

(Acid-modified resin)
The acid-modified resin is used to improve the adhesion between the wood material 4 and the thermoplastic resin composition 5 . When the main component of the thermoplastic resin composition 5 is polyethylene, the acid-modified resin is desirably an acid-modified polyolefin because of its ease of compatibility (high compatibility). In particular, maleic acid-modified polyethylene is preferably used as the acid-modified resin. Here, the above-mentioned “main component” refers to a component that accounts for 50 mass % or more of the mass of the thermoplastic resin composition 5 as a whole.

(Addition amount of acid-modified resin)
The amount of the acid-modified resin to be added is desirably in the range of 3 parts by mass or more and 40 parts by mass or less with respect to 100 parts by mass of the total thermoplastic resin composition. If the addition amount of the acid-modified resin is less than 3 parts by mass, the effect of improving the adhesiveness between the wood material 4 and the thermoplastic resin composition 5 is insufficient, so that the wood base material 10 has sufficient strength. I can't. Moreover, when the amount of the acid-modified resin added exceeds 40 parts by mass, the effect of improving the adhesiveness is limited, and only a slight improvement can be confirmed.
The amount of the acid-modified resin to be added is more preferably in the range of 5 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the total thermoplastic resin composition.

(organic peroxide)
The organic peroxide may be used for radical cross-linking between the raw material mixtures 6 when the raw material mixture 6 is heated and pressurized. The organic peroxide is not particularly limited, and can be appropriately selected from existing materials such as peroxyketals, dialkyl peroxides, diacyl peroxides, and peroxyesters in consideration of reactivity and stability. be done.

Organic peroxides are a kind of radical cross-linking agents, and examples thereof include hydroperoxides, diacyl peroxides, peroxydicarbonates, peroxyesters, peroxycarbonates, dialkyl peroxides, ketone peroxides, and the like. be.

(Additive)
The thermoplastic resin composition 5 may be mixed with additives such as wax. By adding wax as an additive, the water resistance of the wooden base material 10 is further improved. Additives such as wax also serve as lubricants for uniformly mixing the woody material 4 and the thermoplastic resin composition 5 or a plurality of types of thermoplastic resin compositions 5 .

(Method for producing thermoplastic resin composition 5)
The thermoplastic resin composition 5 can be produced in a powder form by a known method. When mixing a plurality of types of materials into the thermoplastic resin composition 5, they are mixed by a known method. For example, if polyethylene powder and acid-modified polyolefin powder are mixed, processing such as freeze-grinding is unnecessary when the thermoplastic resin composition 5 is pulverized, and the thermoplastic resin composition 5 can be easily produced. A powder can be obtained.

Moreover, the thermoplastic resin composition 5 can also be pulverized by a known method such as mechanical pulverization or freeze pulverization from resin pellets produced by a known method. When mixing a thermoplastic resin composition in which resin pellets and powder are mixed, the resin pellets and powder may be mixed and then pulverized, or the resin pellets may be pulverized and then mixed with the powder. good too.

For the thermoplastic resin composition 5, for example, using a uniaxial kneader or a batch type kneader, a plurality of types of thermoplastic resin pellets are heated and kneaded, and then pulverized by a method such as mechanical pulverization or freeze pulverization. be able to. For example, polyethylene pellets and acid-modified polyolefin pellets are heated and kneaded in a uniaxial kneading extruder, pelletized, and the kneaded pellets are freeze-pulverized to obtain a powder of the thermoplastic resin composition 5. can. That is, a powder of the thermoplastic resin composition 5 may be obtained by kneading a plurality of types of the thermoplastic resin composition 5 by an extrusion method. In addition, by mixing a plurality of types of powdery thermoplastic resin compositions, the thermoplastic resin compositions can be mixed more uniformly. 10 can be obtained.

(wood base material 10)
The wood base material 10 is formed by heating and pressurizing a raw material mixture 6 containing a wood material 4 having at least one of powdery and chip-like shapes and a powdery thermoplastic resin composition 5. The normalized CH area calculated from the absorption spectrum obtained in the infrared spectroscopy is adjusted to be within the range of 0.07 or more and 1.00 or less.

Here, Fourier infrared spectroscopy will be described. First, infrared spectroscopy is based on the principle that the amount of infrared light with a wavelength of 2.5 μm to 25 μm absorbed by a substance changes based on the vibration and rotational motion of the substance's molecules. is a measurement method for obtaining information on the chemical structure and state of a substance by measuring the infrared light absorbed by the substance. A specific measurement method is to irradiate a substance with infrared light from a light source, generate an interference wave by synthesizing the divided transmitted light and reflected light, and calculate the signal strength of the interference wave for each wave number. The infrared spectrum is measured by calculating the light intensity of the components. In particular, in the present embodiment, the interference wave is calculated using the Fourier transform method and measured by Fourier infrared spectrometry, which is a method for measuring the infrared spectrum. A graph in which the wavenumber obtained by the above method is plotted on the horizontal axis and the measured absorbance (or transmittance) on the vertical axis is called an infrared absorption spectrum (or infrared transmission spectrum), and a unique pattern is recognized for each substance. be done. At this time, the absorbance on the vertical axis changes in proportion to the concentration and thickness of the substance, and in the case of a crystalline substance, the amount of the crystalline part or the amorphous part, so that the value of the peak intensity at a predetermined wave number changes. Quantitative analysis can also be performed from peak heights and areas.

FIG. 3 shows an infrared absorption spectrum of a general wooden material 4 alone as an example. The woody material 4 has a strong OH group peak derived from cellulose near wave numbers of 3000 to 3500 cm ⁻¹ and a strong C—OH group peak near wave numbers of 900 to 1200 cm ⁻¹ . The area values of the peaks are indicated as S _{0 -H and} S _{C -OH} , respectively, and corrected with the baseline indicated by the dashed line as the background. That is, each range surrounded by a solid line and a broken line shown in FIG. 3 is defined as each peak area value of the OH group and the C—OH group.
In addition, in this embodiment, each peak area value uses a value obtained by averaging the values obtained by measuring at ten different measurement positions in the same sample.

FIG. 4 shows an example of the infrared absorption spectrum of the wooden base material 10 of this embodiment. In addition to the peaks derived from woody material 4, the peaks of CH ₂ groups and CH ₃ groups derived from thermoplastic resin composition 5 strongly exist near wavenumbers of 2700 to 3000 cm ⁻¹ . The peak area values are labeled as S _C-H and are corrected for the baseline indicated by the dashed line as background. That is, each range surrounded by a solid line and a broken line shown in FIG. 4 is defined as each peak area value of an OH group, a C—OH group, and a CH ₂ group and a CH ₃ group.

Based on each peak area value, the composition ratio of the wooden base material 10 is adjusted using the following formula (1) so that the normalized CH area falls within the range of 0.07 or more and 1.00 or less.
Normalized C-H area = S _C-H / (S _O-H + S _C-OH ) Formula (1)

If the normalized CH area is less than 0.07, the ratio of the wooden material 4 is too high, making it difficult to impart practically necessary bending strength. On the other hand, when the normalized CH area exceeds 1.00, the proportion of the thermoplastic resin composition 5 is too high, and deformation of the wooden base material tends to occur during heating and pressurization, which is not preferable. Also, if the wood material 4 and the thermoplastic resin composition 5 are not uniformly mixed, the normalized CH area may locally exceed 1.00. If the wooden material 4 and the thermoplastic resin composition 5 are not uniformly mixed, the bending strength of the wooden base material 10 will vary, which is not preferable.

More preferably, the normalized CH area is in the range of 0.08 to 0.35. If the normalized C—H area is within the above numerical range, it is possible to obtain a good wood base material 10 with higher bending strength and less deformation of the wood base material.

(Manufacturing method of wooden base material 10)
Various known methods can be used for the heating and pressurization used when manufacturing the wooden base material 10. For the manufacturing of the wooden base material 10, press molding using a frame mold as shown in FIG. preferred.
The heating temperature is usually in the range of 120° C. or higher and 250° C. or lower, and must be equal to or higher than the melting point of the thermoplastic resin composition 5. However, if the heating temperature exceeds 250° C., the wooden material 4 will be thermally deteriorated. It may occur markedly. The applied pressure is usually in the range of 10 kgf/cm ² or more and 400 kgf/cm ² or less, and a value appropriately set according to the desired density of the wooden base material 10 is used.

The density and shape of the wooden base material ¹⁰ obtained above ^are appropriately determined according to the application. It is preferably within the range of ³ or more and 1.1 g/cm ³ or less. The woody base material 10 with a lower density is easier to handle when processed as a decorative material, but the woody base material 10 with a higher density can be used as a harder woody base material and decorative material. The woody base material 10 can be not a single layer but a multiple layer of two or more layers, and the density can be changed for each layer.

In the method for manufacturing the wooden substrate 10, the release film 3 shown in FIG. 1 may be used. The release film 3 may be made of any material that does not adhere to the thermoplastic resin composition 5, the metal plate 2 and the metal weight 8, and a fluorine film or the like is preferably used.

Instead of the release film 3, a metal plate 2 subjected to non-adhesive treatment and a metal weight 8 may be used. The non-adhesive treatment may be any treatment that makes it difficult to adhere to the thermoplastic resin composition 5, and fluorine coating or the like is preferably used.

[Second embodiment]
A second embodiment will be described with reference to FIG.
2nd Embodiment is the decorative material 12 which laminated|stacked the design layer 11 which has a design property on the wooden base material 10 which concerns on 1st Embodiment previously demonstrated using FIG.
According to this embodiment, by laminating the design layer 11, which is a designable base material, on the wooden base material 10, designability can be imparted.

That is, the wooden base material 10 can be practically used as a decorative material even when the base material is used alone. The decorative material 12 may be formed by laminating the design layer 11 such as paper or film on the wooden base material 10 .

<Other effects>
(1) The wood base material 10 of the present embodiment includes a wood material 4 having at least one of powdery and chip-like shapes and a thermoplastic resin composition 5, and is obtained by Fourier infrared spectroscopy. The normalized CH area calculated from the obtained absorption spectrum using the following formula (1) is in the range of 0.07 or more and 1.00 or less.
Normalized C-H area = S _C-H / (S _O-H + S _C-OH ) Formula (1)

Here, in formula (1), S _C-H is the area value of the peaks derived from CH ₂ group and CH ₃ group at wave numbers around 2700 to 3000 cm ⁻¹ , and S _O-H is the peak area value at wave numbers around 3000 to 3500 cm ⁻¹ The area value of the peak derived from the OH group, S _C-OH , indicates the area value of the peak derived from the C-OH group near the wave number of 900 to 1200 cm ^-1 .

With such a configuration, the thermoplastic resin composition 5 is used as an adhesive instead of formaldehyde, which causes sick house syndrome, so it is possible to provide the wood base 10 that does not emit harmful substances.
In addition, since the wood base material 10 contains the thermoplastic resin composition 5, it is possible to impart excellent water resistance to the wood base material 10 due to the high water resistance of the thermoplastic resin composition 5 itself. can.

(2) The wood base material 10 of the present embodiment has a normalized CH area calculated from the absorption spectrum obtained by Fourier infrared spectroscopy within the range of 0.08 or more and 0.35 or less. good too.
With such a configuration, it is possible to provide a good wooden base material 10 that has a higher bending strength and is less likely to be deformed.

(3) In the wood base material 10 of the present embodiment, the mass ratio of the wood material 4 and the thermoplastic resin composition 5 (wood material/thermoplastic resin composition) is within the range of 95/5 to 70/30. may
With such a configuration, it is possible to reliably provide the wooden base material 10 having high bending strength.

(4) In the wood base material 10 of the present embodiment, the mass ratio of the wood material 4 and the thermoplastic resin composition 5 (wood material/thermoplastic resin composition) is within the range of 85/5 to 70/30. may
With such a configuration, it is possible to reliably provide the wooden base material 10 having a higher bending strength.

(5) The wooden base material 10 of the present embodiment may contain a mushroom bed as a raw material in the wooden material 4 .
With such a configuration, it is possible to provide the wooden base material 10 that is beneficial in reducing the environmental load.

(6) The wooden base material 10 of the present embodiment may contain polyethylene in the thermoplastic resin composition 5 .
With such a configuration, it is possible to provide the wooden base material 10 having both excellent bending strength and water resistance. In addition, when biomass-derived polyethylene is included, the wooden base material 10 that is beneficial in reducing the environmental load can be provided.

(7) The woody base material 10 of the present embodiment may contain an acid-modified polyolefin in the thermoplastic resin composition 5 .
With such a configuration, it is possible to provide the woody base material 10 with better bending strength.

(8) In the wood base material 10 of the present embodiment, the thermoplastic resin composition 5 contains an acid-modified polyolefin within a range of 3 parts by mass or more and 40 parts by mass or less with respect to 100 parts by mass of the total thermoplastic resin composition. may be
With such a configuration, it is possible to reliably provide the wood base material 10 having a higher bending strength.

(9) The decorative material 12 of the present embodiment is obtained by laminating the design layer 11 having a design property on the wooden base material 10 of the present embodiment.
With such a configuration, it is possible to provide the decorative material 12 having better bending strength and water resistance than conventional decorative materials.

[Example]
Examples 1 to 20 and Comparative Example 1 of the wooden base material according to the first embodiment of the present invention are described below. The present invention is not limited to Examples 1 to 20 below.

(Example 1)
The thermoplastic resin composition of Example 1 is a single high density polyethylene resin (HDPE) pellet. By mechanically pulverizing the resin pellets, a powdery thermoplastic resin composition having an average particle size of 100 μm was obtained as a base resin.
As the woody material, a mushroom bed (average particle size: 2 mm) after harvesting mushrooms was washed and dried. The woody material and the thermoplastic resin composition were dry-mixed at a mass ratio (woody material/thermoplastic resin composition) of 85/15 to obtain a raw material mixture for a woody base material.

This raw material mixture was introduced into an aluminum mold and was heated and pressed with a hot press to obtain the wood base material of this example (pressing conditions: 40 kgf/cm ² , 200° C. for 10 minutes, thickness of base material thickness: 10 mm, substrate density: 0.8 g/cm ³ ).

As described above, the wooden base material of this example does not use harmful substances such as formaldehyde that cause sick house syndrome in the manufacturing process. Therefore, with the wooden base material of this embodiment, it is possible to suppress the diffusion of harmful substances that cause sick house syndrome, such as formaldehyde.

(Example 2)
In Example 2, the mass ratio of the woody material and the thermoplastic resin composition (woody material/thermoplastic resin composition) was changed from "85/15" in Example 1 to "90/10". obtained a wood base material in the same manner as in Example 1.

(Example 3)
In Example 3, the mass ratio of the woody material and the thermoplastic resin composition (woody material/thermoplastic resin composition) was changed from "85/15" in Example 1 to "70/30". obtained a wood base material in the same manner as in Example 1.

(Example 4)
The thermoplastic resin composition of Example 4 is a low-density polyethylene resin (LDPE) pellet alone. A wood base material was obtained in the same manner as in Example 1 except for the above.

(Example 5)
The thermoplastic resin composition of Example 5 is a linear low-density polyethylene resin (LLDPE) pellet alone. A wood base material was obtained in the same manner as in Example 1 except for the above.

(Example 6)
The components and masses of the thermoplastic resin composition of Example 6 are as follows.
(1) High-density polyethylene resin 97 parts by mass (2) Acid-modified polyolefin 3 parts by mass The above (1) to (2) are heated and kneaded in a batch type kneading device, and then mechanically pulverized to obtain powder heat. A plastic resin composition was obtained. A wood base material was obtained in the same manner as in Example 1 except for the above.

(Example 7)
The components and masses of the thermoplastic resin composition of Example 7 are as follows.
(1) High-density polyethylene resin 80 parts by mass (2) Acid-modified polyolefin 20 parts by mass After heating and kneading the above (1) to (2) in a batch type kneading device, mechanical pulverization is performed to obtain heat in powder form. A plastic resin composition was obtained. A wood base material was obtained in the same manner as in Example 1 except for the above.

(Example 8)
The components and masses of the thermoplastic resin composition of Example 8 are as follows.
(1) High-density polyethylene resin 60 parts by mass (2) Acid-modified polyolefin 40 parts by mass After heating and kneading the above (1) to (2) in a batch type kneading device, mechanical pulverization is performed to obtain heat in powder form. A plastic resin composition was obtained. A wood base material was obtained in the same manner as in Example 1 except for the above.

(Example 9)
The components and masses of the thermoplastic resin composition of Example 9 are as follows.
(1) High-density polyethylene resin 100 parts by mass (2) 1.5 parts by mass of organic peroxide (trade name: Perhexa C, manufactured by NOF Corporation) Batch kneading equipment for above (1) and (2) After heating and kneading at , mechanical pulverization was performed to obtain a powdery thermoplastic resin composition. A wood base material was obtained in the same manner as in Example 1 except for the above.

(Example 10)
The components and masses of the thermoplastic resin composition of Example 10 are as follows.
(1) High-density polyethylene resin 90 parts by mass (2) Acid-modified polyolefin 10 parts by mass (3) Organic peroxide (trade name: Perhexa C, manufactured by NOF Corporation) 1.5 parts by mass Above (1) to After heating and kneading (3) in a batch type kneader, the mixture was mechanically pulverized to obtain a powdery thermoplastic resin composition. A wood base material was obtained in the same manner as in Example 1 except for the above.

(Example 11)
The components and masses of the thermoplastic resin composition of Example 11 are as follows.
(1) High-density polyethylene resin powder 90 parts by mass (2) Acid-modified polyolefin powder 10 parts by mass (3) Organic peroxide (trade name: Perhexa C, manufactured by NOF Corporation) 1.5 parts by mass Above (1 ) to (3) were dry mixed to obtain a powdery thermoplastic resin composition. A wood base material was obtained in the same manner as in Example 1 except for the above.

(Example 12)
The thermoplastic resin composition of Example 12 is a single polypropylene resin (PP) pellet. By mechanically pulverizing the resin pellets, a powdery thermoplastic resin composition was obtained. A wood base material was obtained in the same manner as in Example 1 except for the above.

(Example 13)
The components and masses of the thermoplastic resin composition of Example 13 are as follows.
(1) Polypropylene resin powder 90 parts by mass (2) Acid-modified polyolefin powder 10 parts by mass Similar to Example 12, polypropylene resin powder was obtained by mechanically pulverizing resin pellets. By dry mixing the above (1) and (2), a powdery thermoplastic resin composition was obtained. A wood base material was obtained in the same manner as in Example 1 except for the above.

(Example 14)
In Example 14, the mass ratio of the woody material and the thermoplastic resin composition (woody material/thermoplastic resin composition) was changed from "85/15" in Example 1 to "65/35". obtained a wood base material in the same manner as in Example 1.

(Example 15)
In Example 15, the mass ratio of the woody material and the thermoplastic resin composition (woody material/thermoplastic resin composition) was changed from "85/15" in Example 1 to "96/4". obtained a wood base material in the same manner as in Example 1.

(Example 16)
The thermoplastic resin composition of Example 16 is a single polypropylene resin (PP) pellet. By mechanically pulverizing the resin pellets, a powdery thermoplastic resin composition was obtained. For the woody material of Example 16, a material obtained by washing and drying wood chips (average particle size: 2 mm) was used. A wood base material was obtained in the same manner as in Example 15 except for the above.

(Example 17)
The wooden material of Example 17 was obtained by washing and drying wood chips (average particle size: 2 mm). A wood base material was obtained in the same manner as in Example 12 except for the above.

(Example 18)
The thermoplastic resin composition of Example 18 is a single polypropylene resin (PP) pellet. By mechanically pulverizing the resin pellets, a powdery thermoplastic resin composition was obtained. A wood base material was obtained in the same manner as in Example 15 except for the above.

(Example 19)
The wooden material of Example 19 was obtained by washing and drying wood chips (average particle size: 2 mm). A wood base material was obtained in the same manner as in Example 15 except for the above.

(Example 20)
The components and masses of the thermoplastic resin composition of Example 20 are as follows.
(1) Polypropylene resin powder 80 parts by mass (2) Acid-modified polyolefin powder 20 parts by mass Polypropylene resin powder was obtained by mechanically pulverizing resin pellets in the same manner as in Example 12. By dry mixing the above (1) and (2), a powdery thermoplastic resin composition was obtained.
As the woody material of Example 20, a material obtained by washing and drying wood chips (average particle size: 2 mm) was used. A wood base material was obtained in the same manner as in Example 15 except for the above.

(Comparative example 1)
In Comparative Example 1, a wooden base material was obtained in the same manner as the so-called particle board.
Specifically, a drum-type blender is used to mix a wooden material and an adhesive, and the mixture is naturally dropped and spread without applying external force such as pressurization or suction pressure. A urea resin adhesive was used as the adhesive, and the wood material and the adhesive were mixed at a mass ratio (wood material/adhesive) of 85/15. Next, the wood base material of this comparative example was obtained by compacting the mixture.

(Evaluation of wooden base material)
For Examples 1 to 20 and Comparative Example 1 described above, Fourier infrared spectroscopy (normalized CH area measurement), mechanical strength, water resistance, and substrate deformation were evaluated.

(Fourier infrared spectroscopy: normalized CH area measurement)
For the Fourier infrared spectroscopic measurement, a Fourier infrared spectrometer (Spectrum Spotlight 400) manufactured by Perkin Elmer was used to obtain an absorption spectrum from 4000 cm ⁻¹ to 400 cm ⁻¹ . The normalized CH area is calculated from the obtained absorption spectrum using the following formula (1).
Normalized C-H area = S _C-H / (S _O-H + S _C-OH ) Formula (1)

Here, in formula (1), S _C-H is the area value of the peaks derived from CH ₂ group and CH ₃ group at wave numbers around 2700 to 3000 cm ⁻¹ , and S _O-H is the peak area value at wave numbers around 3000 to 3500 cm ⁻¹ The area value of the peak derived from the OH group, S _C-OH , indicates the area value of the peak derived from the C-OH group near the wave number of 900 to 1200 cm ^-1 .
In the Fourier-type infrared spectroscopic measurement, a sample having a normalized C—H area within the range of 0.07 or more and 1.00 or less is regarded as passing.

(mechanical strength)
As for mechanical strength, bending strength was measured by a method based on JISA5908. The evaluation criteria for the mechanical strength with respect to the measured value (unit: N/mm ² ) were as follows based on the JIS standard values.
The evaluation criteria for mechanical strength were evaluated in three stages of "○", "△", and "×" as follows, and "○" and "△" were accepted, and "×" was rejected.
〇: 13 or higher (passed)
△: 8 or more and less than 13 (pass)
×: less than 8 (failed)

(water resistant)
The water resistance was determined by measuring the water absorption thickness swelling rate by a method based on JISA5908. Based on the JIS standard values, the water resistance evaluation criteria for the measured values (unit: %) are as follows.
The evaluation criteria for water resistance were evaluated in three stages of "○", "△", and "×" as follows, and "○" and "△" were accepted, and "×" was rejected.
○: less than 8 (pass)
△: 8 or more and less than 12 (pass)
×: 12 or more (failed)

(Base material deformation)
Base material deformation is a state in which the surface of the base material is partially swollen, and is mainly caused by stagnation of gas generated inside the base material during pressing. Since the deformation of the base material is more clearly reflected by the state of the edge of the base material, the appearance of the edge of the base material was visually evaluated.
The evaluation criteria for base material deformation were evaluated in three stages of “◯”, “Δ”, and “×” as follows, and “◯” and “Δ” were accepted, and “×” was rejected.
〇: No voids (accepted)
△: Traces of voids (accepted)
×: There is a void (failed)

(Evaluation results)
The evaluation results of the wooden substrate are shown in Table 1 below.
The "raw material mixing ratio" in the examples in the table indicates the (wood material/thermoplastic resin composition) mass ratio, and the "raw material mixing ratio" in the comparative examples in the table indicates the (wood material/adhesive) mass ratio. indicates

(Evaluation results of Fourier infrared spectroscopy)
Only Comparative Example 1 failed in the evaluation of Fourier infrared spectroscopy. The woody base materials containing polyolefin in the thermoplastic resin composition as in Examples 1 to 20 have a characteristic peak near 2700 to 3000 cm ⁻¹ , so the normalized CH area is large. When the normalized CH area is calculated for the wooden material alone, it is 0.05, so almost no peak due to the adhesive of Comparative Example 1 is detected near 2700 to 3000 cm ⁻¹ .

When comparing Examples 1 to 20, Example 14, in which the amount of the thermoplastic resin composition is increased, has the largest normalized CH area, and Examples 15, 16, and 18 to 20, in which the amount is small, are the largest. The normalized CH area becomes smaller.

(Evaluation result of mechanical strength)
In terms of mechanical strength, all of Examples 1 to 20 and Comparative Example 1 passed. Among them, 12 cases of Examples 2, 4, 5, 8, 12, 13, and 15 to 20 include "△" in the evaluation results.
In Examples 2, 15, 16, 18 to 20, the ratio of the wooden material was high, and it is considered that the mechanical strength decreased. In Examples 4 and 5, LDPE and LLDPE were used as the base resins, respectively, so it is considered that the mechanical strength was lower than that of HDPE. In Example 8, 40 parts of acid-modified polyolefin was blended, and it is considered that the mechanical strength was lowered. Since PP was used as the base resin in Examples 12 to 13 and 17, it is considered that the mechanical strength was lower than that of HDPE.

(Evaluation result of water resistance)
Only Comparative Example 1 failed in water resistance. The conventional method using an adhesive is inferior in water resistance to Examples 1 to 20 of the present invention. Comparing Examples 1 to 20, 13 cases of Examples 1 to 5, 11 to 12, and 15 to 20 contain "△".
Examples 1 to 5, 12, 15 to 19 are material formulations containing neither acid-modified polyolefin nor organic peroxide, and it is considered that the water resistance was insufficient (slightly inferior). Examples 11 and 20 are material formulations containing both the acid-modified polyolefin and the organic peroxide. ing. It is considered that the powder mixture was not uniformly mixed and the water resistance was insufficient (slightly inferior). In Example 14, although the material formulation contained neither acid-modified polyolefin nor organic peroxide, the proportion of the thermoplastic resin composition was high, so the water resistance was good.

(Evaluation result of substrate deformation)
In terms of substrate deformation, all of Examples 1 to 20 and Comparative Example 1 passed. Among them, the evaluation results including "Δ" are two cases of Examples 3 and 14.
It is believed that the inclusion of 30 parts of the thermoplastic resin composition in Example 3 and the inclusion of 35 parts of the thermoplastic resin composition in Example 14 facilitated substrate deformation.

(Comprehensive evaluation results)
As a comprehensive evaluation result, Examples 1 to 20 were "passed" in all evaluation items, and as is clear from Table 1, the wood base material of the present invention has excellent mechanical strength and water resistance. However, it was shown that there is no problem with base material deformation. In addition, since the wooden base material of the present invention does not contain harmful substances that cause sick house syndrome, it is possible to suppress the diffusion of harmful substances that cause sick house syndrome, such as formaldehyde.

DESCRIPTION OF SYMBOLS 1... Jig for preparing a wooden substrate, 2... Metal plate (bottom surface), 3... Release film, 4... Wood material, 5... Thermoplastic resin composition, 6... Raw material mixture, 7... Metal plate for thickness adjustment, 8... Metal weight, 9... Press machine top plate, 10... Wooden base material, 11... Design layer, 12... Decorative material

Claims (11)

A woody base material comprising a woody material having at least one of powdery and chip-like shapes and a thermoplastic resin composition,
The normalized CH area calculated using the following formula (1) from the absorption spectrum obtained by Fourier infrared spectrometry is in the range of 0.07 or more and 1.00 or less. wood base material.
Normalized C-H area = S _C-H / (S _O-H + S _C-OH ) Formula (1)
(Here, in formula (1), S _C-H is the area value of the peaks derived from CH ₂ groups and CH ₃ groups at wave numbers around 2700 to 3000 cm ^-1 , and S _O-H is wave numbers around 3000 to 3500 cm ^-1 The area value of the peak derived from the OH group, and S _C-OH represents the area value of the peak derived from the C-OH group near the wave number of 900 to 1200 cm ^-1 .) 2. The wood base material according to claim 1, wherein the normalized CH area is in the range of 0.08 or more and 0.35 or less. Claim 1 or Claim 2, wherein the mass ratio of the woody material and the thermoplastic resin composition (woody material/thermoplastic resin composition) is in the range of 95/5 to 70/30. The wooden base material according to . Claim 1 or Claim 2, wherein the mass ratio of the woody material and the thermoplastic resin composition (woody material/thermoplastic resin composition) is in the range of 85/15 to 70/30. The wooden base material according to . 5. The wooden base material according to any one of claims 1 to 4, wherein the wooden material contains fungal bed as a raw material. 6. The wood base material according to any one of claims 1 to 5, wherein the thermoplastic resin composition contains polyethylene. 7. The wood base material according to any one of claims 1 to 6, wherein the thermoplastic resin composition contains an acid-modified polyolefin. 8. The wood base material according to claim 7, wherein the content of said acid-modified polyolefin is in the range of 3 parts by mass or more and 40 parts by mass or less with respect to 100 parts by mass of the total thermoplastic resin composition. A decorative material comprising the wooden base material according to any one of claims 1 to 8 and a designable base material laminated thereon. a step of heating and pressurizing a raw material mixture containing a woody material having at least one of powdery and chip-like shapes and a powdery thermoplastic resin composition to form a woody base material;
The wood base material has a normalized CH area calculated using the following formula (1) from the absorption spectrum obtained by Fourier infrared spectroscopy within the range of 0.07 or more and 1.00 or less. A method for producing a wooden base material, characterized in that
Normalized C-H area = S _C-H / (S _O-H + S _C-OH ) Formula (1)
(Here, in formula (1), S _C-H is the area value of the peaks derived from CH ₂ groups and CH ₃ groups at wave numbers around 2700 to 3000 cm ^-1 , and S _O-H is wave numbers around 3000 to 3500 cm ^-1 The area value of the peak derived from the OH group, and S _C-OH represents the area value of the peak derived from the C-OH group near the wave number of 900 to 1200 cm ^-1 .) The step of producing the powdery thermoplastic resin composition includes:
A step of kneading a plurality of types of thermoplastic resin compositions by an extrusion method;
pulverizing the kneaded thermoplastic resin composition into powder;
The method for producing a woody base material according to claim 10, comprising:

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