JP2003145514A - High strength member and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high strength member having excellent water resistance and strength and an environment-friendliness. SOLUTION: The high strength member uses a member in which vegetable fibers dispersed by a non-fibrous component and/or a fibrous decomposed product originated on a natural organic material is fixed. This member has a wet tensile strength when the member is dipped in water for 4 hours at room temperature and then lifted from the water of 8 MPa or more, a wet tensile strength when the member is not dipped in the water of 20 MPa or more. The member has biodegradability. The member is useful as the high strength member for a building, fittings, for a furniture, for a transportation or packaging product or for a mechanical or an electrical product.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-strength member useful as a member for construction and fittings, a member for furniture, a member for transportation / packaging products, a member for mechanical / electrical products, and the like.

[0002]

2. Description of the Related Art Conventionally, various wood products have been used as members for buildings and fittings. For example, plate-like wood, wood thin plates (veneers), and plywood (veneer plates) obtained by laminating the thin plates. ) Are used. However, since these wood products are produced by processing the timber cut out from the forest as it is without defibration or crushing, it is difficult to effectively use small-diameter wood (thinned wood) and waste wood. It contributes to the destruction.

On the other hand, as the above-mentioned wood products, products obtained from defibrated wood (fiber board) and products obtained from crushed wood (particle board) are also known. Since these wood products can effectively use small-diameter wood and waste wood, it can be said that they are eco-friendly products. However, in order to bond the defibrated fibers and the crushed wood, a synthetic resin adhesive (urea melamine resin, phenol resin, etc.) is generally used. When these synthetic resin adhesives are used, harmful gases (such as formaldehyde) are generated in the process of use, and the biodegradability of wood products disappears when they are discarded after use. Have a bad effect. Therefore, there is a demand for products that are more environmentally friendly.

On the other hand, fiber boards, particle boards and the like which do not use a synthetic resin adhesive as an adhesive component are also known. For example, the binding force of hemicellulose and lignin in fibers has been used for a long time. In recent years, a mixture of fibrous substance, powdered starch, and water is formed into a mat, and steam at a temperature of 160 ° C. and high-temperature air at a temperature of 150 ° C. are simultaneously blown onto the mat for 60 seconds, followed by drying. Fiberboard (Japanese Patent Laid-Open No. 9-2
No. 07230) or a starchy material such as waste paper, leftover rice and the like as a raw material, and a board obtained by mixing boron and a substance that causes a similar chemical change (JP-A-11-138514).
Japanese patent publication). However, fiber boards and particle boards that do not use these synthetic resin adhesives have insufficient water resistance, and their strength extremely decreases when they are wet with water. According to the above-mentioned JP-A No. 11-138514, by mixing starch and the like such as waste paper and leftover rice with boron and the like, the strength is increased and moreover the water resistance stronger than that of gypsum board is obtained. Based on the knowledge obtained from the above, it cannot be considered that the strength is increased and the water resistance is increased by mixing.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is a high-strength member excellent in water resistance and strength, and environmentally friendly, and its production. To provide a method.

[0006]

As a result of intensive studies to solve the above problems, the present inventors have found that (1) dispersed plant fibers (such as disintegrated waste paper) and (2) After molding with a binder derived from natural organic substances (animal excrement, non-fibrous components such as garbage, fiber decomposition products such as grass charcoal), this molded product is subjected to strong conditions exceeding drying conditions. When heated with, the plant fiber can be firmly solidified with a binder even though it has biodegradability, and its strength (tensile strength) and water resistance (wet tensile strength) become extremely high. The present invention has been completed by discovering that it is extremely useful as a member for furniture or a machine / electric product. The strength and water resistance of the molded product are extremely high.
By heat-treating under strong conditions that exceed the drying conditions, such as hydroxyl groups in plant fibers (eg, hydroxyl groups of cellulose) and carboxyl groups in non-fibrous components or fiber decomposition products (eg, grass charcoal humic acid). It is presumed that this may be due to dehydration condensation with a carboxyl group or phenolic hydroxyl group in the acid, a terminal carboxyl group of the protein, etc. to form a network structure. The formation of this new chemical bond can be confirmed by the change in the infrared absorption spectrum (IR) before and after the heat treatment.

That is, the biodegradable high-strength member according to the present invention is produced by a binder derived from a natural organic substance (non-fibrous components such as animal excrement and foods; fibrous decomposition products such as grass charcoal). A member in which dispersed plant fibers (wood fibers, seed hair fibers, bast fibers, stem stem fibers, etc.) are hardened, and wet tensile strength (strength when pulled up after being immersed in water at room temperature for 4 hours). Is 8 MPa or more, and the tensile strength when not wet (when not immersed in water) is 20 MPa or more. This high-strength member has biodegradability, as well as for construction and fittings, furniture,
It is extremely useful as a high-strength member for transportation / packaging products or mechanical / electrical products.

The high-strength member is a stack of a plurality of flat members in which plant fibers dispersed by non-fibrous components derived from natural organic substances and / or fiber decomposition products are solidified, and each flat member is made of non-fiber. The structure may be such that they are bonded to each other by a quality component and / or a fiber decomposition product. Further, the high-strength member is a collection of a large number of small pieces or granular members in which plant fibers dispersed by a non-fibrous component derived from a natural organic material and / or a fiber decomposition product are solidified, or each small piece or The granular members may be connected to each other by a non-fibrous component and / or a fiber decomposition product.

The high strength member may further contain an auxiliary binder such as urea, humic acid and its salt, phosphoric acid and its salt.

The high-strength member can be produced by drying and further heat-treating a molded body in which (1) dispersed plant fibers and (2) a binder derived from a natural organic substance are mixed with each other.

[0011]

DETAILED DESCRIPTION OF THE INVENTION

[Raw Material] The high-strength member of the present invention uses at least (1) dispersed plant fiber and (2) a binder derived from a natural organic material (non-fibrous component, fiber decomposition product, etc.) as a raw material. Since both the plant fiber and the binder (non-fibrous component, fiber decomposition product, etc.) are derived from natural organic matter, they have biodegradability and can reduce the load on the environment.

(Plant Fiber) In the present invention, dispersed plant fiber is used as the plant fiber. Here, "dispersed" means that timber is not used as it is, and "dispersed plant fiber" includes, for example, pulp obtained from wood (mechanical pulp, chemical pulp), pulverized wood. Etc. are included. By using dispersed plant fiber, it is not always necessary to use timber cut from the forest as a raw material, in addition to timber, waste wood generated in the processing process,
Waste of processed wood products can also be used as a raw material, reducing the environmental impact.

As the plant fiber, various plant fibers can be used, and the fiber length thereof is not particularly limited, either short fiber or long fiber can be used. Preferred plant fibers include wood fibers (newspaper, paper, advertising paper, corrugated cardboard, pulp and other papers), seed hair fibers (cotton etc.), bast fibers (hemp etc.), stem stem fibers (straw etc.), etc. Is mentioned.

Since the plant fiber is contained in a large amount in waste plant fiber [waste paper, pulp waste material, used clothes (waste cloth), etc.], it is desirable to use waste plant fiber as a raw material. When waste plant fiber is used as a raw material, waste can be effectively used, and thus the load on the environment can be further reduced. When used paper is used as the plant fiber (for example, when used paper is used so that the ratio of used paper in the plant fiber is 80% by mass or more, preferably 90% by mass or more, particularly 100% by mass), when pulp is used, In comparison, the strength of the product (high-strength member) and the water resistance (wet tensile strength) tend to be weak, but according to the present invention, the product ( The strength and water resistance (wet tensile strength) of the high-strength member) can be increased.

The plant fiber raw materials may be used alone or in combination of two or more kinds. Preferably, two or more types of wood fibers such as papers are used in combination. When two or more kinds are combined, the strength of the product (high-strength member) tends to be lower than in the case of using them alone, but in the present invention, the strength of the product or the strength of the product is increased by performing a strong heat treatment that exceeds the drying conditions described later. Since the water resistance (wet tensile strength) is enhanced, high product characteristics (strength, water resistance) can be maintained even if two or more kinds of plant fiber raw materials are combined. Therefore, the used paper can be used as a raw material as it is without being separated.

(Binder) The non-fibrous component constituting the binder is not particularly limited as long as it is a component derived from a natural organic substance, but preferably animal excrement (particularly feces), foods (food or food). Waste) can be used. As the fiber decomposition product, grass peat (also called peat) can be used. These binders contain a large amount of components containing groups active for dehydration condensation reaction such as hydroxyl group, amino group and carboxyl group. Therefore, in the heat treatment described below, the strength and water resistance of the product (high-strength member) become extremely high, probably because a bond is formed between the binder and the plant fiber and / or the binder by dehydration.

(Animal excrement) As animal excrement, excrement of wild animals may be used, but excrement of livestock such as horses, cows and pigs (particularly feces) is preferable. Livestock excrement (livestock manure, etc.) is easily available and inexpensive, and not only can manufacturing costs be reduced, but also waste can be effectively used, which can further reduce the burden on the environment.

The animal dung may be mixed with bedding (rice husks, sawdust, bark, etc.) used for raising livestock, or may be mixed with a urine component. The animal excrement may be fermented. For example, when animal excrement is aerobically fermented (ripening treatment such as composting), not only odor can be removed by microorganisms, but also strength and water resistance of the product (high-strength member) can be increased.

(Foods) As foods, foods, food wastes (raw garbage, for example, raw garbage discarded from supermarkets, convenience stores, restaurants, etc.) can be used. Since these foods are easily available and inexpensive, the manufacturing cost of the product (high-strength member) can be reduced. Especially for food waste, the load on the environment can be further reduced because the waste can be effectively used.

It is desirable that the foods contain protein or starch (preferably protein, especially protein which is difficult to dissolve in water or can maintain a solid form in water). Foods containing protein or starch can remarkably enhance the strength and water resistance of the product (high-strength member).

The foods may be fermented. For example, anaerobic fermentation of foods can enhance the strength and water resistance of the product (high-strength member). The strength and water resistance can be increased because organic acids (polylactic acid, etc.) are generated by fermentation, and when mixed with plant fibers and then heat-treated, these organic acids bond with the plant fibers (cellulose). It is estimated to be because.

On the other hand, foods may prevent spoilage. For example, spoilage can be prevented by blocking contact with air or by storing at low temperature (for example, about 0 to −30 ° C.).

(Fiber Decomposition Product) As the fiber decomposition product, fibers decomposed by the action of microorganisms can be used.
A preferable fiber decomposition product is a component (such as grass charcoal) containing humic acids (humic acid, a salt thereof, or a microbial decomposition product thereof).

The above-mentioned peat charcoal means that plants such as reeds, sedges, and water moss grow and die in cold swamps and wetlands, and under anaerobic conditions, they last for hundreds to tens of thousands of years. It means that it was deposited in an incompletely decomposed state. The grass charcoal thus formed is a natural organic acid (such as humic acid or its salt) derived from the anaerobic oxidation of the remains of plants.
Is contained in a large amount (for example, 20 to 50% by mass).
The higher the proportion of humic acid in the grass charcoal, the more advantageous it is in terms of cost and effect. Although the chemical structure of the humic acid has not been sufficiently clarified, its elemental composition is 45 to 6 carbon.
0% by mass, 4 to 6% by mass of hydrogen, 0.5 to 5% by mass of nitrogen, and the balance is mostly oxygen. The molecular weight is widely distributed in the range of about several hundreds to several hundreds of thousands. Furthermore, humic acid has a large amount of carboxylic acid groups and phenolic hydroxyl groups. Since the carboxylic acid group and the phenolic hydroxyl group (active functional group) are ion-exchangeable and can form a chelate compound, humic acid having these active functional groups can be converted into various salts (sodium salt, Forming potassium salts, calcium salts, iron salts, etc.). The grass charcoal contains cellulose and lignin derived from plant remains. The mined grass charcoal contains fibrous components derived from the cellulose, and although the fibrous constituents in this grass charcoal have a size that can be observed with the naked eye, the fibrous constituents in the grass charcoal are long. Its strength is greatly reduced by anaerobic decomposition over the years, and it easily becomes a powder by mechanical grinding. That is, since it does not substantially have the strength enough to be called fibrous material, it is regarded as a fiber decomposition product in the present invention.

Since grass charcoal is easily available and inexpensive, the manufacturing cost can be reduced. Furthermore, since grass charcoal has an adsorptive property, the malodor can be removed when used in combination with animal excrement and spoiled foods. In addition, grass charcoal has an anti-rot effect.
Therefore, if the foods are mixed with the foods during storage, the spoilage of the foods can be suppressed.

The ratio of the vegetable fiber and the binder is not particularly limited, but the preferable amount of the vegetable fiber (on a dry mass basis) is 5 parts by mass or more (preferably, 100 parts by mass of the total amount of the vegetable fiber and the binder). Is 10 parts by mass or more, more preferably 15 parts by mass or more) and 95 parts by mass or less (preferably 90 parts by mass or less, more preferably 85 parts by mass or less). If the proportion of plant fibers is too large or too small, the strength and water resistance of the product (high-strength member) will decrease.

On the other hand, the proportion of each component (animal excrement, non-fibrous components such as foods, fiber decomposition products such as grass charcoal) in the binder is not particularly limited, but when each component is used alone Compared with, the strength and water resistance of the product (high-strength member) can be increased when the components are used in combination. In particular, when foods containing protein and grass charcoal are used together, the strength and water resistance of the product (high-strength member) can be remarkably increased as compared with the case where each component is used alone.

When a combination of a binder (animal excrement, non-fibrous components such as foods, fiber decomposition products such as grass charcoal) is used, the ratio of the fiber decomposition products (grass charcoal) is based on dry mass, For example, 1 to 99% by mass, preferably 20 to
70% by mass, more preferably 30 to 60% by mass.

Although the fiber decomposition products (such as grass charcoal) have biodegradability, the biodegradation rate is slower than that of the non-fibrous components. Therefore, the higher the proportion of the fiber decomposed material in the binder, the longer the period of use of the high-strength member of the present invention can be extended. However, even if the proportion of non-fibrous components (animal excrement, foods, etc.) in the binder is high, the high-strength member of the present invention may be used for a long period of time depending on the usage environment. it can.

(Auxiliary Binder) In the present invention, an auxiliary binder may be used together when the binder is used. As the auxiliary binder, various known adhesives can be used as long as the biodegradability of the high-strength member of the present invention is not lost. Preferred auxiliary binders include binders that do not substantially impair the biodegradability of the high-strength member, such as urea, humic acid or its salt, phosphoric acid or its salt, and the like. The salts include alkali metal salts (sodium salt, potassium salt, etc.), alkaline earth metal salts, ammonium salts, etc. These auxiliary binders are amino groups,
Since it has a carboxyl group or a phosphoric acid group, the high-strength member obtained in the present invention can have a network structure, and the strength and water resistance of the high-strength member can be further improved.

Amount of auxiliary binder added (dry mass basis)
Is not particularly limited, but is, for example, about 0 to 60 parts by mass, preferably 1 to 30 parts by mass with respect to 100 parts by mass of the binder.
The amount is about parts by mass, more preferably about 2 to 10 parts by mass.

(Additive) In the present invention, various additives (waterproofing agent, flame retardant, colorant, preservative, etc.) may be used in combination with the plant fiber and the binder, if necessary. .
As these additives, various known additives can be used as long as the biodegradability of the high-strength member of the present invention is not lost. The additives may be used alone or in combination of two or more.

[Manufacturing Method] The high-strength member of the present invention is obtained by drying and further heat-treating a molded body in which the above-mentioned essential raw materials (dispersed vegetable fiber and binder) are mixed. The drying and heat treatment may be performed separately, or may be performed by a series of heating in which the heating is further continued after the dry state is achieved without performing the drying separately.

The drying means is not particularly limited, and external heating (heating by radiant heat such as heating using a heating furnace, heating by heat transfer, etc.), internal heating (dielectric heating such as microwave heating, high frequency dielectric heating, etc.), etc. Various conventional heating means can be utilized.

The water content in the dried product is, for example, 20 mass% or less (preferably 15 mass% or less), 5 mass% or more (preferably 7 mass% or more).

What is important in the present invention is to heat-treat the dried body (including the one dried in the continuous heating) to obtain the strength (tensile strength when not wet) and water resistance (wet tensile strength) of the molded body. Strength). That is, plant fiber contains cellulose, and binders such as animal excrement (particularly fermented animal excrement), foods, and grass charcoal have various components [urea, starch (Or a fermentation product thereof), a protein (or a fermentation product thereof), humic acids, etc.] are contained. The above-mentioned cellulose, urea, starch (or a fermentation product thereof), protein (or a fermentation product thereof), humic acids and the like have many active groups capable of reacting with each other such as a hydroxyl group, an amino group and a carboxyl group. Therefore, when the dried product is further heated, the components having the active group are bound to each other by an intermolecular dehydration action (dehydration condensation reaction) or the like, and a chemical bond is formed between the plant fiber-binder and the binder-binder. It is presumed that as a result of the formation, a mesh structure is formed in the molded product, and the integrity (strength, water resistance, etc.) of the molded product is enhanced. It is presumed that the chemical bond is formed on the basis that the infrared absorption spectrum (IR) changes before and after heating the molded product.

As the heat treatment means, similar to the drying means, external heating (heating by radiant heat such as heating using a heating furnace, heating by heat transfer, etc.), internal heating (dielectric heating such as microwave heating, high frequency dielectric heating, etc.) Various conventional heating means such as).

The heat treatment conditions can be appropriately selected according to the heat treatment means. For example, when heating is performed using a heating furnace, the heat treatment temperature (the highest temperature reached in the heating furnace) is, for example, 105
℃ or more, preferably 110 ℃ or more, more preferably 1
It is 20 ° C or higher. The stronger the heat treatment condition, the easier the intermolecular dehydration condensation reaction will occur, so the strength and water resistance of the high-strength member can be increased, and the biodegradability is suppressed within the range where the biodegradability does not disappear. be able to.
Therefore, the high-strength member can be used for a long period of time. If the heat treatment conditions are too strong, the strength and water resistance will rather deteriorate, probably because the member begins to thermally decompose. Therefore,
The heat treatment temperature is, for example, 270 ° C. or lower, preferably 25
The temperature is 0 ° C. or lower, and more preferably 230 ° C. or lower. The heat treatment time (duration of the highest reached temperature) can be appropriately set according to the heat treatment temperature and the strength and water resistance of the obtained high-strength member.

Even when other heating means is used, heating may be performed under the same conditions as the heating by the heating furnace.

In the present invention, it is important to enhance the strength and water resistance by further heat-treating the molded body in which the essential raw materials (the dispersed plant fiber and the binder) are mixed, and further heat-treating it. As long as the water resistance can be increased, the heat treatment may be performed at any stage of the manufacturing process of the high strength member. For example, a mixture of essential raw materials is formed into a predetermined member shape (a shape of a building / joint member, a furniture member, a transportation / packing product member,
It may be manufactured by a method of drying and heat treatment after molding into a shape of a mechanical / electrical product part). In addition, the mixture of essential raw materials is once formed into a preliminary shape such as a flat shape (sheet shape, plate shape, etc.), a powder shape, a small piece shape, etc., and the shape of a predetermined member is formed by stacking or gathering the preliminary shape material. Shapes of building and fitting materials, furniture materials, machinery,
It may be heat-treated after being molded into the shape of a part for electric appliances).

The preform may be dried in advance or heat-treated before being laminated or assembled. When preliminarily dried, it is desirable to wet the preform or to further coat or impregnate the preform with the binder when the dried preforms are assembled or laminated. . When heat-treated in advance, it is desirable to further coat or impregnate the pre-molded body with the binder when the heat-treated pre-molded body is assembled or laminated.

When the above mixture is prepared, it is necessary to mix the respective components in a substantially homogeneous manner. Therefore, pulverization (or cutting) may be carried out depending on the shape of the raw material. For example, when a fermentation component is used as a binder, it is not necessary to pulverize the lump component because it has almost disappeared, but when the fermentation component is not used, the lump component remains in a large amount, and therefore it is pulverized. Is preferred. Further, it is desirable that the plant fiber is also crushed (or cut) in order to increase the degree of mixing. The timing of pulverization (or cutting) is not particularly limited, and may be before mixing, during mixing, or after mixing.

The mixing and pulverizing may be either wet or dry, but when the mixture is used to form a sheet or to form a predetermined member, the mixing and pulverizing (particularly pulverizing) is performed wet. Is desirable. Since plant fibers (particularly papers) are strongly bound to each other by hydrogen bonds in a dry state, a large amount of energy is consumed by dry crushing, whereas energy can be saved by wet crushing. Further, since the fibers of papers have already been cut in the manufacturing process, there is a possibility that the fibers may be cut into finer pieces when the waste material (waste paper) of this paper is used as a raw material and is pulverized by a dry method. On the other hand, in wet pulverization, there is little risk that the fibers will be cut during pulverization, and each fiber can be dissociated while maintaining the fiber length of the raw material. Binders (especially animal excrement, foods, grass charcoal, etc.) originally contain a large amount of water, and thus it is convenient to grind them with a wet method.

The molding method of the mixture can be appropriately selected according to the shape of the molded body. For example, when the mixture is molded into a predetermined member shape or a plate shape, mold molding (water absorbing or water permeable mold) is performed. Molding, etc.) and plastic molding can be used. The plastic forming is a method of forming by utilizing the plastic deformability of a mixture (or a kneaded product), and examples thereof include a forming method using a press forming machine, a roller, a potter's wheel and the like. When the mixture is preformed into a sheet, papermaking (papermaking method), mold molding (molding using a water-absorbing or water-permeable mold, etc.), molding using a roller and the like can be used. When the mixture is formed into powder particles or small pieces, for example, a rolling granulation method, a method in which kneading and extrusion and subsequent cutting are combined can be used.

In the present invention, it is desirable to press the molded product prior to the drying and heat treatment. By applying pressure, the density of the high-strength member after heat treatment can be increased, and the strength and water resistance of the high-strength member can be further increased. The pressure applied is, for example, 0.5 MPa or more (usually 1 MPa or more) and 100 MPa or less (usually 80 MPa or less).

When the auxiliary binder is used, the auxiliary binder may be used together in the step of using the binder. When an additive is used, it may be added at any stage of the manufacturing process. However, when the thermal stability of the additive is low, it is desirable to add it by impregnation or the like after the heat treatment.

The high-strength member obtained by the present invention has biodegradability because the essential raw materials are derived from natural organic substances. Furthermore, since it is heat treated, it has strength (tensile strength in non-wet condition) and water resistance (tensile strength in wet condition).
Is also excellent.

The tensile strength of the high-strength member of the present invention in a non-wet state is, for example, 20 MPa or more (preferably 25 MP).
a or more, more preferably 30 MPa or more), 80MP
a or less (generally 60 MPa or less, more commonly 4
0 MPa or less).

The wet tensile strength of the high-strength member of the present invention (tensile strength immediately after immersion in water at room temperature for 4 hours) is
For example, it is 8 MPa or higher (preferably 10 MPa or higher, more preferably 15 MPa or higher), 50 MPa or lower (generally 40 MPa or lower, more generally 25 MPa or lower).

The high-strength member may be subjected to surface treatment (painting, coating with a sheet, etc.) as necessary.

The shape of the high-strength member is not particularly limited, and may have various shapes other than plate shape, columnar shape (square columnar shape, cylindrical shape, etc.) according to the application.

The high-strength member of the present invention has various uses in which wood has been conventionally used, for example, construction / joint use (structural materials, exterior materials, interior materials, doors, etc.), furniture applications, transportation / packaging applications. Useful in (boxes, pallets, etc.). Further, it is also useful as various applications in which plastic products are conventionally used, for example, parts for mechanical and electrical products.

[0053]

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to the following examples, and may be appropriately applied within the scope of the above and the following points. It is of course possible to make changes and implement them, and all of them are included in the technical scope of the present invention.

Experimental Example 1 Cardboard (water content 10.7% by mass), grass charcoal (produced in Liaoning Province of the People's Republic of China, water content 45.6% by mass), food waste [waste from restaurants (12 stores)] To which water was added to adjust the water content to 80.0% by mass]. The amount of each raw material used is the mass with the water content,
Cardboard = 672 kg, grass charcoal = 368 kg, food waste = 1000 kg. The mixture was paper-made using a paper machine and dried at a temperature of 80 ° C. or lower to prepare a dry sheet. The thickness of this sheet was 0.23 mm, and the density immediately after drying was 0.62 g / cm ³ .

On the other hand, 26 g of fish, 27 g of white fish croquette,
15 g of fish tempura, 18 g of vegetable tempura, 20 g of chicken,
Bento waste consisting of 10 g of omelet, 9 g of kamaboko, 14 g of thick fried tofu, 11 g of konjac, 33 g of vegetables and pickles, and 224 g of rice was mixed with water and crushed with a mixer (sheet-to-sheet binder; raw garbage).

The dried sheet was shredded into a size of 200 mm square, and the inter-sheet binder (garbage) was applied to the surface of the sheet by 1 piece.
After applying each sheet evenly, 20 sheets were stacked, pressed at a pressure of 20 MPa, and dried at a temperature of 100 to 105 ° C. until the water content became about 10% by mass to prepare a laminated plate.

This laminated plate was put in an electrothermal constant temperature box,
A high-strength plate was manufactured by performing heat treatment at a temperature of 180 ° C. for 1 hour.

Experimental Example 2 As an inter-sheet binder, humic acid (adjusted to pH = 11 to dissolve humic acid in water and then neutralized with phosphoric acid until pH = 6), protein [yellowfin tuna: Egg white: starch = 1: 1: 1 (mass ratio on dry basis)], an aqueous solution containing 5% by mass of starch (potato starch) [humic acid: protein: starch = 1: 1: 2 (mass on dry basis) A high-strength plate was manufactured in the same manner as in Experimental Example 1 except that the ratio was used.

Experimental Example 3 A high-strength plate was manufactured in the same manner as in Experimental Example 2 except that the pressing pressure at the time of stacking sheets was 60 MPa.

Experimental Examples 4 to 6 When heat-treating the laminated plate, instead of heat treatment using an electric heating type constant temperature box, heating was performed by microwave heating (frequency = 2450 MHz, rated high-frequency output 500 W) for 2 minutes. High-strength plates were manufactured in the same manner as in Examples 1 to 3 except that heating was performed for 2 minutes.

The tensile strengths of the high-strength plates obtained in Experimental Examples 1 to 6 in a non-wet state were measured according to JIS K7113, and the high-strength plates were immersed in water at room temperature for 4 hours, The tensile strength (wet tensile strength) immediately after being pulled up was also measured according to JIS K7113. Both tensile strengths are average values of 5 measurements.

The results are shown in Table 1.

[0063]

[Table 1]

As is clear from Table 1, according to Experimental Examples 1 to 6, since the corrugated fiberboard is bonded with the binder, the obtained plate material has strength (tensile strength in non-wet condition) and water resistance. Excellent (wet tensile strength).

[0065]

According to the present invention, since dispersed plant fibers are used as a raw material, it is not always necessary to use wood itself, and deforestation can be reduced. Moreover, since the plant fiber and the binder derived from a natural product (non-fibrous component, fiber decomposition product) are used as raw materials, biodegradability can be imparted to the obtained member. Therefore, a high-strength member that is friendly to the environment can be obtained. Furthermore, since the plant fiber and the binder are heat-treated under a strong condition exceeding drying conditions, a dehydration condensation bond is formed between the respective raw materials, or the strength and water resistance of the obtained member are increased. It is possible to provide a high-strength member that is extremely useful as a member for construction / jointing, furniture, transportation / packing, or mechanical / electrical products.

Continued front page    (72) Inventor Koetsu Matsunaga             6-2 Goryoutorinokocho, Yamashina-ku, Kyoto-shi, Kyoto Prefecture             Royal Heights Hyuga 102 Daichi Co., Ltd.             Koen Kyoto Yamashina Research Center (72) Inventor Kunishi Nakamura             136 Itama, 2 Kanuma City, Tochigi Prefecture F term (reference) 2B260 AA20 BA07 BA19 BA30 CB01                       EA05 EB02 EB05

Claims (7)

[Claims] 1. A member in which a plant fiber dispersed by a non-fibrous component derived from a natural organic substance and / or a fiber decomposition product is solidified, and a wet tension when it is immersed in water at room temperature for 4 hours and then pulled up. High strength for construction / joints, furniture, transportation / packaging products, or mechanical / electrical products with biodegradability characterized by a strength of 8 MPa or more and a tensile strength of 20 MPa or more when not immersed in water. Element. 2. A plurality of planar members in which plant fibers dispersed by a non-fibrous component derived from a natural organic substance and / or a fiber decomposition product are solidified are laminated, and each planar member is a non-fibrous component and / or The high-strength member according to claim 1, wherein the high-strength members are bonded to each other by a fiber decomposition product. 3. A large number of small pieces or granular members in which plant fibers dispersed by a non-fibrous component derived from a natural organic substance and / or a decomposed product of fibers are solidified, and each small piece or granular member is gathered. The high-strength member according to claim 1, wherein the two are bonded to each other by a non-fibrous component and / or a fiber decomposition product. 4. The plant fiber is wood fiber, seed hair fiber,
The high-strength member according to any one of claims 1 to 3, which is at least one kind selected from bast fibers and stem and stem fibers. 5. The high-strength member according to claim 1, wherein the non-fibrous component is at least one selected from animal excrement and foods, and the fiber decomposition product is grass charcoal. 6. The high-strength member according to claim 1, further comprising at least one auxiliary binder selected from the group consisting of urea, humic acid and its salts, and phosphoric acid and its salts. . 7. A molded body in which (1) dispersed plant fibers and (2) non-fibrous components derived from natural organic substances and / or decomposed products of fibers are mixed with each other is further heat-treated after drying. The method for manufacturing a high-strength member according to claim 1, wherein