JP2023101911A - Wooden substrate, decorative material, and manufacturing method of wooden substrate - Google Patents

Abstract

To provide a wooden substrate exhibiting practical mechanical strength and durability by suppressing emission of harmful substances causing a sick house syndrome such as formaldehyde and so forth, and to provide a decorative material provided with the wooden substrate and a manufacturing method of the wooden substrate.SOLUTION: A wooden substrate 20 relating to one embodiment according to the present invention comprises a wooden material 11 in at least one of powder shape and chip shape, and a thermoplastic resin composition 12, and organic polybasic acid, and polyhydric alcohol. A mass ratio (mass of organic polybasic acid/mass of polyhydric alcohol) of the organic polybasic acid to the polyhydric alcohol is 50/50 to 90/10. The total content of the organic polybasic acid and the polyhydric alcohol falls within 2 parts by mass or more and 10 parts by mass or less, based on 100 parts by mass of the total mass of the wooden material 11 and the thermoplastic resin composition 12.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a wood base material, a decorative material, and a method for producing a wood base material.

A woody base material is a base material obtained by heating and pressurizing a mixture of a woody material such as wood powder, woody chips, and woody fiber with an adhesive. This wooden base material is called particle board, medium-density fiberboard, etc., 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.
As adhesives for wooden substrates, urea resin-based adhesives, melamine resin-based adhesives, and phenolic resin-based adhesives are usually used together with a curing agent 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, a fiber board is produced by using an adhesive mainly composed of powdered sugar and powdered polycarboxylic acid, mixing it with vegetable fibers and heat-pressing. A method has been proposed (see paragraph [0017] of Patent Document 1). In addition, conventionally, a method for producing a laminate containing a wood base material using an adhesive made of polyvinyl alcohol and water as a formaldehyde-free adhesive has been proposed (see paragraph [0017] of Patent Document 2 and FIG. 1).
However, wood base materials using the above-described conventional adhesives are not practically sufficient in mechanical properties such as bending strength and water resistance.

JP 2016-55620 A Japanese Patent No. 5553279

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a wooden base, a decorative material, and a method for producing a wooden base that suppresses the diffusion of harmful substances that cause sick house syndrome, such as formaldehyde, and has practical mechanical strength and water resistance.
As a result of intensive studies to solve the above-described problems, the inventors found that the above-described problems can be solved by adding an organic polybasic acid and a polyhydric alcohol to the powder mixture in a wood base material formed by heating and pressurizing a powder mixture of a wood material and a thermoplastic resin composition, and have arrived at the present invention.

A wood base according to an aspect of the present invention is a wood base containing a wood material having at least one of powdery and chip-like shapes, a thermoplastic resin composition, an organic polybasic acid and a polyhydric alcohol, wherein the mass ratio between the organic polybasic acid and the polyhydric alcohol (mass of the organic polybasic acid/mass of the polyhydric alcohol) is from 50/50 to 90/10, and the total content of the organic polybasic acid and the polyhydric alcohol is from 50/50 to 90/10. It is characterized by being in the range of 2 parts by mass or more and 10 parts by mass or less with respect to the total mass of 100 parts by mass with the thermoplastic resin composition.

A decorative material according to an aspect of the present invention is characterized in that a design layer having a design property is laminated on the wooden base material described above.

A method for producing a wood base material according to an aspect of the present invention is the above-described method for producing a wood base material, and is characterized by including a step of mixing a mixture of the wood material and the powdery thermoplastic resin composition with a solution containing the organic polybasic acid and the polyhydric alcohol to prepare a raw material mixture.

According to one aspect of the present invention, it is possible to provide a wooden base material that suppresses the emission of harmful substances that cause sick building syndrome such as formaldehyde and that has practical mechanical strength and water resistance, a decorative material provided with the wood base material, and a method for producing the wood base material.

FIG. 4 is a schematic diagram for explaining the manufacturing process of the wooden base material according to the first embodiment of the present invention. FIG. 5 is a schematic cross-sectional view showing the configuration of a decorative material according to a second embodiment of the present invention;

[First embodiment]
FIG. 1 shows a wooden base material 20 according to a first embodiment of the invention. The wooden base material 20 is called a particle board or a medium density fiberboard depending on the type of the wooden material 11, and is used in a wide range of applications such as base material for floors and walls, fittings and furniture.
As shown in FIG. 1, the wood base material 20 is formed by heating and pressurizing a raw material mixture 10 containing a wood material 11 having at least one of powdery and chip-like shapes, a powdery thermoplastic resin composition 12, an organic polybasic acid and a polyhydric alcohol. The wooden base material 20 does not contain harmful substances that cause sick house syndrome, such as formaldehyde. 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 20 .
The wood material 11, the thermoplastic resin composition 12, and the organic polybasic acid and polyhydric alcohol constituting the wood base material 20 are described below.

(wood material 11)
The wooden material 11 has at least one of powdery and chip-like shapes. 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. The average particle size of the wooden material 11 in this embodiment is, for example, within the range of 100 μm or more and 20 mm or less.

The wood material 11 includes, for example, wood flour, wood fibers, and chips obtained by crushing wood, and thinned wood, sawdust, and waste wood, for example, can be used as raw materials.
In addition, the wooden material 11 may be a candidate other than wood if it contains a cellulose component like wood, such as bamboo, hemp, coconut fiber, and walnut shell.

As a raw material for the wooden material 11, for example, a large amount of used mushroom bed generated 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 about 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.
In this embodiment, when the fungus bed is used as the wooden material 11, the ratio of the fungal bed to the entire volume of the wooden material 11 may be in the range of 1% or more and 100% or less, preferably 50% or more and 100% or less. If the content of the fungal bed is within the above numerical range, the manufacturing cost can be reduced as compared with the case of using ordinary wood chips.

(Thermoplastic resin composition 12)
One or more thermoplastic resin compositions 12 are used in the raw material mixture 10 . The thermoplastic resin composition 12 also contains one or more thermoplastic resins. Further, the shape of the thermoplastic resin composition 12 is, for example, powder.

Various thermoplastic resins such as polyester, polyamide, polyolefin, ethylene-propylene-diene rubber, ethylene vinyl acetate, and silicone rubber can be used, but polyolefin is preferable in terms of mechanical strength and water resistance of the wooden base material 20, and among these, polyethylene is preferable.

The polyethylene resin is not particularly limited, and is appropriately selected and used from existing materials such as high-density polyethylene, low-density polyethylene, ultra-low-density polyethylene, linear low-density polyethylene, etc. in consideration of the fluidity of the raw material mixture 10.

Further, the thermoplastic resin composition 12 may contain other thermoplastic resins in addition to the thermoplastic resin such as polyethylene described above. Other thermoplastic resins may be resins containing acidic functional groups (that is, acid-containing resins) in order to improve the adhesion of the wooden material 11 to thermoplastic resins (polyethylene, etc.). Examples of acid-containing resins that can be used include maleic anhydride-modified polyethylene, maleic anhydride polypropylene, maleic anhydride-modified polyolefin, ethylene (meth)acrylic acid copolymer, and itaconic anhydride-modified polyethylene.

(Organic polybasic acids and polyhydric alcohols)
The organic polybasic acid and the polyhydric alcohol are used to improve the water resistance and strength of the woody base material 20 through dehydration condensation between the carboxyl groups of the organic polybasic acid and the hydroxyl groups contained in the polyhydric alcohol or the woody material 11 when the raw material mixture 10 is heated and pressurized. Anhydrides of organic polybasic acids can also be used in the same manner.

<Organic polybasic acid (and anhydride)>
Organic polybasic acids (and anhydrides) suitable for the present embodiment include succinic acid, glutaric acid, adipic acid, malic acid, tartaric acid, fumaric acid, maleic acid, maleic anhydride, citric acid, anicotic acid, itaconic acid, and itaconic anhydride. Of these, trivalent polybasic acids and polybasic acids having unsaturated bonds are particularly preferred.

A trivalent polybasic acid and a polybasic acid having an unsaturated bond can be used alone, but when used in combination, the physical properties of the base material can be greatly improved compared to when they are used alone.

Examples of the trivalent polybasic acid include citric acid, anicotic acid, itaconic acid, and itaconic anhydride, and citric acid is particularly preferred in terms of versatility.
Examples of polybasic acids having unsaturated bonds include fumaric acid, maleic acid, maleic anhydride, anicotic acid, itaconic acid, and itaconic anhydride. Maleic acid is particularly preferred in terms of versatility and safety.

<Polyhydric alcohol>
A suitable polyhydric alcohol in the present embodiment is a trihydric or higher polyhydric alcohol.
Specific examples of polyhydric alcohols suitable for the present embodiment include ethylene glycol, propylene glycol, glycerin, pentaerythritol, sorbitol, and the like, but propylene glycol and glycerin are preferable in terms of versatility and safety, and glycerin is particularly preferable because it has a large effect of improving the strength and water resistance of the wooden base material 20.

The mass ratio between the organic polybasic acid and the polyhydric alcohol (mass of the organic polybasic acid/mass of the polyhydric alcohol) in the present embodiment is 50/50 to 90/10. If the mass ratio deviates from this range, the strength and water resistance of the wooden base material 20 may decrease.
The mass ratio of the organic polybasic acid to the polyhydric alcohol (mass of the organic polybasic acid/mass of the polyhydric alcohol) in the present embodiment is preferably 60/40 to 80/20, more preferably 65/35 to 75/25.

The total content of the organic polybasic acid and the polyhydric alcohol in the present embodiment is in the range of 2 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the total mass of the woody material 11 and the thermoplastic resin composition 12. If the total content of the organic polybasic acid and the polyhydric alcohol is less than 2 parts by mass, the water resistance may decrease, and if the total content of the organic polybasic acid and the polyhydric alcohol exceeds 10 parts by mass, the strength may decrease.
The total content of the organic polybasic acid and the polyhydric alcohol in the present embodiment is preferably within the range of 4 parts by mass or more and 8 parts by mass or less, and more preferably within the range of 5 parts by mass or more and 6 parts by mass or less.

Also, the organic polybasic acid and the polyhydric alcohol are usually added to the raw material mixture 10 as an aqueous solution. Since the aqueous solution containing the organic polybasic acid and the polyhydric alcohol has stickiness, the thermoplastic resin composition 12 adheres to the wooden material 11 in the raw material mixture 10 via the organic polybasic acid and the polyhydric alcohol.

The raw material mixture 10 and the thermoplastic resin composition 12 may contain an organic peroxide to improve the performance of the wood base material 20 . In other words, the organic peroxide may be blended in the thermoplastic resin composition 12, or may be blended in the raw material mixture 10 even if it is not blended in the thermoplastic resin composition 12. The organic peroxide causes cross-linking of the thermoplastic resin and grafting of the organic polybasic acid to the thermoplastic resin when the wood base material 20 is heated and pressurized, thereby improving the strength and water resistance of the wood base material 20 .

As organic peroxides, for example, existing materials such as peroxyketals, dialkyl peroxides, diacyl peroxides, and peroxyesters are appropriately selected and used in consideration of reactivity and stability.

The amount of the organic peroxide compounded with respect to the total mass of 100 parts by mass of the wooden material 11 and the thermoplastic resin composition 12 is in the range of 0.1 parts by mass or more and 3 parts by mass or less. The amount of the organic peroxide compounded is preferably in the range of 0.3 parts by mass or more and 2 parts by mass or less, and more preferably in the range of 0.8 parts by mass or more and 1.5 parts by mass or less. If the amount of the organic peroxide to be blended is less than the above range, the substrate performance effect will not be exhibited, and if it exceeds the above range, the substrate performance will be lowered.

The thermoplastic resin composition 12 containing multiple components can be produced by various known methods. For example, a uniaxial kneader or a batch kneader can be used to heat and knead the thermoplastic resin and other raw materials, and then powdered by a method such as mechanical pulverization or freeze pulverization.

The mass ratio of the wooden material 11 and the thermoplastic resin composition 12 (woody material/thermoplastic resin composition) is preferably in the range of 95/5 to 65/35. If the content of the wooden material 11 exceeds the above range, the wooden base material 20 cannot be provided with sufficient strength. On the other hand, if the content of the wooden material 11 is less than the above range, the raw material mixture 10 may not be uniformly mixed, and the strength and water resistance of the wooden base material 20 may be lowered.
The mass ratio (woody material/thermoplastic resin composition) between the wooden material 11 and the thermoplastic resin composition 12 is preferably in the range of 90/10 to 70/30, more preferably in the range of 85/15 to 75/25.

(Preparation of raw material mixture 10)
In the process of preparing the raw material mixture 10, in order to obtain the raw material mixture 10 used in the present embodiment, it is preferable to add and mix an aqueous solution containing an organic polybasic acid and a polyhydric alcohol to a mixture of the wood material 11 and the thermoplastic resin composition 12. For example, the raw material mixture 10 can be obtained by adding the aqueous solution with a sprayer or the like while stirring the woody material 11 and the thermoplastic resin composition 12 .

(Manufacturing method of wooden base material 20 by heating and pressurizing raw material mixture 10)
Various known methods can be used for heating and pressurizing the raw material mixture 10, but press molding using a frame mold is preferable.
The heating temperature of the raw material mixture 10 must be higher than the melting point of the thermoplastic resin contained in the raw material mixture 10 (thermoplastic resin composition 12), and is usually 120°C to 250°C. If the heating temperature exceeds 250° C., thermal deterioration of the wooden material 11 occurs significantly.
The pressurization pressure of the raw material mixture 10 is usually 10 kgf/cm ² to 200 kgf/cm ² , and a value appropriately set according to the desired density of the wooden base material 20 is used.
The density and shape of the wooden base material 20 are appropriately determined according to the application. The density of the wooden base material 20 is preferably 0.5 g/cc to 1.2 g/cc, more preferably 0.6 g/cc to 1.1 g/cc. If the density of the wooden base material 20 is within the above numerical range, the mechanical strength of the entire wooden base material 20 is further improved. Furthermore, if the density of the wooden base material 20 is within the range of the above numerical values, the pore volume contained in the whole wooden base material 20 is reduced, so that heat resistance and cold resistance are also improved.

[Second embodiment]
A second embodiment will be described with reference to FIG.
2nd Embodiment is the decorative material 30 which laminated|stacked the design layer 31 which has a design property on the wooden base material 20 which concerns on 1st Embodiment previously demonstrated using FIG.
According to this embodiment, by laminating the design layer 31 on the wooden base material 20, it is possible to impart a design property.
That is, the wooden base material 20 can be put to practical use as a decorative material by itself. However, in order to give the wooden base material 20 a more excellent design property, as shown in FIG.

[Effect of this embodiment]
The wood base material 20 according to the present embodiment includes a wood material 11 having at least one of powdery and chip-like shapes, a thermoplastic resin composition 12, and an organic polybasic acid and a polyhydric alcohol. It is within the range of 2 parts by mass or more and 10 parts by mass or less with respect to the total mass of 100 parts by mass with the object 12 .
With such a configuration, the wooden base material 20 does not contain harmful substances that cause sick house syndrome, such as formaldehyde, so that it is possible to suppress the diffusion of harmful substances that cause sick house syndrome, such as formaldehyde. Further, since the woody base material 20 contains specific amounts of the organic polybasic acid and the polyhydric alcohol, the woody base material 20 can be imparted with excellent water resistance and mechanical strength due to the reaction between the organic polybasic acid and the polyhydric alcohol.

Moreover, the organic polybasic acid of the present embodiment may contain at least one of a trivalent polybasic acid and a polybasic acid having an unsaturated bond.
With such a configuration, the reactivity between the organic polybasic acid and the polyhydric alcohol is further increased, and excellent water resistance and mechanical strength can be imparted to the wooden base material 20 .

Moreover, the polyhydric alcohol of the present embodiment may contain a trihydric or higher polyhydric alcohol.
With such a configuration, the cross-linking density between the organic polybasic acid and the polyhydric alcohol is further increased, and excellent water resistance and mechanical strength can be imparted to the wooden base material 20 .

Moreover, the organic peroxide may be contained within a range of 0.1 parts by mass or more and 3 parts by mass or less with respect to 100 parts by mass of the total mass of the woody material 11 and the thermoplastic resin composition 12 of the present embodiment.
With such a configuration, crosslinking of the thermoplastic resin and grafting of the organic polybasic acid to the thermoplastic resin occur when the wood base material 20 is heated and pressurized, so that the strength and water resistance of the wood base material 20 can be improved.

In addition, the woody material 11 of the present embodiment may contain a mushroom bed as a raw material.
With such a configuration, it is possible to manufacture the wood material 11 in consideration of the environment.

Further, the decorative material 30 of the present embodiment may be obtained by laminating the design layer 31 on the wooden base material 20 .
With such a configuration, the design of the wooden base material 20 can be enhanced.

In addition, the decorative material 30 of the present embodiment uses a wooden base material 20 containing a wood material 11 having at least one of powdery and chip-like shapes, a thermoplastic resin composition 12, and an organic polybasic acid and a polyhydric alcohol. 2 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the total mass of 11 and the thermoplastic resin composition 12, and a design layer having a design property is laminated on the wooden base material 20.
With such a configuration, the decorative material 30 does not contain harmful substances that cause sick house syndrome, such as formaldehyde, so that it is possible to suppress the diffusion of harmful substances that cause sick house syndrome, such as formaldehyde. In addition, since the wooden base material 20 constituting the decorative material 30 contains a specific amount of organic polybasic acid and polyhydric alcohol, the reaction between the organic polybasic acid and the polyhydric alcohol can impart excellent water resistance and mechanical strength to the wood base material 20.

Further, the method for producing the wood base material 20 of the present embodiment includes a step of mixing a mixture of the wood material 11 having at least one of powdery and chip-like shapes and the powdery thermoplastic resin composition 12 with a solution containing an organic polybasic acid and a polyhydric alcohol to prepare the raw material mixture 10.
In addition, the method of manufacturing the wooden base material 20 of the present embodiment may further include a step of heating and pressurizing the raw material mixture 10 to form the wooden base material 20 after the step of preparing the raw material mixture 10 .
With such a configuration, the manufactured wooden base material 20 does not contain harmful substances that cause sick house syndrome, such as formaldehyde, so that the emission of harmful substances that cause sick house syndrome, such as formaldehyde, can be suppressed. In addition, since the manufactured wood base material 20 contains specific amounts of the organic polybasic acid and the polyhydric alcohol, it is possible to impart excellent water resistance and mechanical strength to the wood base material 20 due to the reaction between the organic polybasic acid and the polyhydric alcohol.

[Example]
Examples 1 to 11 and Comparative Examples 1 to 4 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 11 below.

(Example 1)
In Example 1, high-density polyethylene powder (density: 0.952 g/cm ³ ) was directly used as the thermoplastic resin composition.
Citric acid (hereinafter “CA”) was used as the organic polybasic acid, and propylene glycol (hereinafter “PG”) was used as the polyhydric alcohol. CA and PG were dissolved in pure water so that the mass ratio (CA/PG) was 80/20 and the total concentration of CA and PG was 60%, thereby preparing an aqueous acid-alcohol solution.
As the woody material, a material obtained by washing and drying the mushroom bed after harvesting mushrooms was used.
While stirring the woody material and the thermoplastic resin composition with a mixer, the acid alcohol aqueous solution was sprayed with an air spray, and stirring was continued to obtain a raw material mixture having the following ratio (parts by mass).
Wood material/thermoplastic resin composition/acid alcohol=90/10/5 (ratio of non-volatile components)

This raw material mixture was introduced into an aluminum mold and was heated and pressed with a hot press apparatus to obtain a wood base material of Example 1 having a density of 0.7 g/cc (pressing conditions: 30 kgf/cm ² , 210° C. for 10 minutes, base material thickness: 10 mm).

(Example 2)
In Example 2, the mass ratio of citric acid and propylene glycol in Example 1 was set to CA/PG=60/40, and the woody base material of Example 2 was obtained in the same manner as in Example 1.

(Example 3)
In Example 3, the citric acid of Example 1 was replaced with maleic acid (hereinafter "MA"), and the mass ratio of maleic acid and propylene glycol was set to MA/PG = 80/20.

(Example 4)
In Example 4, the mass ratio of maleic acid and propylene glycol in Example 3 was set to MA/PG=60/40, and the woody base material of Example 4 was obtained in the same manner as in Example 3.

(Example 5)
In Example 5, part of the citric acid (CA) in Example 1 was replaced with maleic acid (MA), and the mass ratio of CA/MA/PG was 40/40/20 (organic polybasic acid/polyhydric alcohol=80/20).

(Example 6)
In Example 6, the propylene glycol (PG) of Example 5 was replaced with glycerin (G), and the mass ratio of CA/MA/G was set to 40/40/20.

(Example 7)
In Example 7, the mass ratio of (woody material/thermoplastic resin composition/acid alcohol) of Example 6 was set to 90/10/3, and the woody base material of Example 7 was obtained in the same manner as in Example 6.

(Example 8)
In Example 8, the mass ratio of (woody material/thermoplastic resin composition/acid alcohol) of Example 6 was set to 90/10/8, and the woody base material of Example 8 was obtained in the same manner as in Example 6.

(Example 9)
In Example 9, an organic peroxide (Perbutyl P (manufactured by NOF Corporation); 0.1 parts by mass) was added to the raw material mixture of Example 6, and the woody base material of Example 9 was obtained in the same manner as in Example 6 except for this.

(Example 10)
In Example 10, an organic peroxide (Perbutyl P (manufactured by NOF Corporation); 1 part by mass) was added to the raw material mixture of Example 6, and the woody base material of Example 10 was obtained in the same manner as in Example 6.

(Example 11)
In Example 11, a wooden base material of Example 11 was obtained in the same manner as in Example 10 except that the amount of the organic peroxide used in Example 10 was changed to 3 parts by mass.

(Comparative example 1)
In Comparative Example 1, the mass ratio of the organic polybasic acid and polyhydric alcohol of Example 6 was set to CA/MA/G=48/48/4 (organic polybasic acid/polyhydric alcohol=96/4), and otherwise the wood base material of Comparative Example 1 was obtained in the same manner as in Example 6.

(Comparative example 2)
In Comparative Example 2, the mass parts of the organic polybasic acid and polyhydric alcohol of Example 6 were CA/MA/G = 20/20/60 (organic polybasic acid/polyhydric alcohol = 40/60), and otherwise the same method as in Example 6 was used to obtain a wood base material of Comparative Example 2.

(Comparative Example 3)
In Comparative Example 3, the mass ratio of (woody material/thermoplastic resin composition/acid alcohol) of Example 6 was set to 90/10/1, and the woody base material of Comparative Example 3 was obtained in the same manner as in Example 6.

(Comparative Example 4)
In Comparative Example 4, the mass ratio of (woody material/thermoplastic resin composition/acid alcohol) of Example 6 was set to 90/10/12, and the woody base material of Comparative Example 4 was obtained in the same manner as in Example 6.

(Evaluation of wooden base material)
The physical properties of the wooden substrate were evaluated based on the following five points: (1) mechanical strength and (2) water resistance.
(1) Mechanical strength Mechanical strength was measured by bending strength by a method based on JISA5908. The mechanical strength evaluation criteria for the measured value (unit: N/mm ² ) were set in four stages of “◎”, “○”, “△” and “×” as follows, and “◎”, “○” and “△” were accepted, and “×” was rejected.
◎: 18 or more (pass)
○: 13 or more and less than 18 (pass)
△: 8 or more and less than 13 (pass)
×: less than 8 (failed)

(2) Water resistance Water resistance was determined by measuring the water absorption thickness expansion rate by a method based on JISA5908. The water resistance evaluation criteria for the measured value (unit: %) are as follows: "◎", "○", "△" and "×".
◎: less than 5 (passed)
○: 5 or more and less than 8 (pass)
△: 8 or more and less than 12 (pass)
×: 12 or more (failed)

(Evaluation Results) The evaluation results of the wooden substrate are shown in Table 1 below. It was Examples 1 to 11 that both physical property evaluations were "accepted".

In Comparative Examples 1 and 2, the mass ratio of the organic polybasic acid to the polyhydric alcohol is too large or too small, and in Comparative Examples 3 and 4, the amount of the acid alcohol component (organic polybasic acid and polyhydric alcohol) (woody material and thermoplastic resin composition) is too small or too large.

(Evaluation results of Examples 1 to 11)
Comparing the evaluation results of Examples 1 to 11, it is found that the two evaluation results are both "○" or "⊚" in five cases of Examples 6 to 10, and Example 10 is the best mode.
Regarding the physical properties of woody substrates, it has been suggested that the combined use of organic polybasic acids is more advantageous than the use of citric acid and maleic acid alone, the use of polyhydric alcohols such as glycerin is more advantageous than propylene glycol, and the combination of organic peroxides is more advantageous.

As described above, a wooden material having at least one of powdery and chip-like shapes, a thermoplastic resin composition, an organic polybasic acid and a polyhydric alcohol are included, the mass ratio between the organic polybasic acid and the polyhydric alcohol (mass of the organic polybasic acid/mass of the polyhydric alcohol) is 50/50 to 90/10, and the total content of the organic polybasic acid and the polyhydric alcohol is 2 parts by mass per 100 parts by mass of the total mass of the woody material and the thermoplastic resin composition. It was shown that the wooden base material has excellent mechanical strength and water resistance within the range of 10 parts by mass to 10 parts by mass.

10 raw material mixture 11 wood material 12 thermoplastic resin composition 20 wood base material 30 decorative material 31 design layer

Claims (8)

A woody base material comprising a woody material having at least one of powdery and chip-like shapes, a thermoplastic resin composition, an organic polybasic acid and a polyhydric alcohol,
The mass ratio between the organic polybasic acid and the polyhydric alcohol (mass of organic polybasic acid/mass of polyhydric alcohol) is 50/50 to 90/10,
The total content of the organic polybasic acid and the polyhydric alcohol is in the range of 2 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the total mass of the woody material and the thermoplastic resin composition. 2. The wood base material according to claim 1, wherein the organic polybasic acid contains at least one of a trivalent polybasic acid and a polybasic acid having an unsaturated bond. 3. The wood base material according to claim 1, wherein the polyhydric alcohol contains a trihydric or higher polyhydric alcohol. 4. The wooden base according to any one of claims 1 to 3, wherein the organic peroxide is contained in a range of 0.1 parts by mass or more and 3 parts by mass or less with respect to 100 parts by mass of the total mass of the woody material and the thermoplastic resin composition. The wooden base material according to any one of claims 1 to 4, wherein the wooden material contains fungal bed as a raw material. A decorative material using a wood base material containing a wood material having at least one of powdery and chip-like shapes, a thermoplastic resin composition, an organic polybasic acid and a polyhydric alcohol,
The mass ratio between the organic polybasic acid and the polyhydric alcohol (mass of organic polybasic acid/mass of polyhydric alcohol) is 50/50 to 90/10,
The total content of the organic polybasic acid and the polyhydric alcohol is in the range of 2 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the total mass of the woody material and the thermoplastic resin composition,
A decorative material comprising the wooden base material and a design layer laminated thereon. A method for producing a wood base material according to any one of claims 1 to 5,
A method for producing a wood base material, comprising the step of mixing a mixture of the wood material and the powdery thermoplastic resin composition with a solution containing the organic polybasic acid and the polyhydric alcohol to prepare a raw material mixture. 8. The method for producing a woody base material according to claim 7, further comprising the step of heating and pressurizing the raw material mixture to form the woody base material after the step of preparing the raw material mixture.

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