JPH0716964A - Laminated material and its manufacture - Google Patents

Abstract

PURPOSE:To manufacture a laminated material which is hot-press-molded in a short time, suitable for mass production, managed at a low production cost, high in dynamic strength and dimensional stability, not swollen with water and rich in use. CONSTITUTION:A vegetable stem of a straight line part possessing the skin part consisting mainly of lignocellulose and the porous pith part or a cavity is divided into a plurality of parts by either causing the skin part to be cracked or opening in the direction of a fiber. A thermosetting liquid is infiltrated into the vegetable stem and the infiltrated thermosetting liquid is dried. A plurality of the vegetable stems are arranged, a sheetlike matter 30 is formed, these are laminated and a laminated body 40 is formed, then the laminated body is pressurized, pressurized and heated steam or gas is injected in the middle of pressurization, the laminated body is hot-press- molded and a laminated material is obtained. The laminated material includes also the laminated material comprised of a sheetlike matter and boardlike matter. Lamination may be performed by either applying an adhesive agent to the sheetlike matter or the boardlike matter before lamination or applying the adhesive agent to the sheetlike matter by forming the sheetlike matter without infiltlating the thermosetting liquid into the vegetable stem.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-strength laminated material mainly made of grass stems such as high-grade corn, corn and sugar cane, and a method for producing the same. More specifically, the present invention relates to a laminated material used for building materials, furniture materials, decoration materials, heat insulating materials, sound absorbing materials, display materials, various work materials, and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, wood boards, furniture materials, display materials, sound absorbing materials, and various work materials include sawdust, plywood, laminated wood, particle boards, fiber boards and the like. Further, solid materials or foams of synthetic resins such as polystyrene, polyethylene, polyurethane, phenol resin, melamine resin and urea resin are used for display materials, sound absorbing materials, heat insulating materials and the like. Particleboard and fiberboard are used to cut wood chips and fibers,
A synthetic resin adhesive is mixed and heat-cured to form a plate. These boards make it possible to effectively use raw materials such as wood because they are made into pieces or fibers of wood, but on the other hand, because the cellulose fibers are finely chopped, the mechanical strength and dimensional stability of the boards are stable. It has the disadvantage of being inferior in sex.

Wood materials such as sawn timber, plywood, laminated wood, particleboard and fiberboard, which are used in large amounts for construction materials, etc., are mainly made of natural wood, so that wood resources have been exhausted in recent years. As the supply progresses, there is a limit to the amount of supply, and in the future it will not be possible to sufficiently meet strong demand, and there is a risk that prices will rise significantly. In addition, synthetic resin foams such as polystyrene, polyethylene, polyurethane, and phenolic resins are widely used as display materials and heat insulating materials because they are lightweight, have good workability, and have excellent heat insulating properties. Since these resins depend on petroleum resources, there is a risk of future quantitative securing due to resource finiteization problems.

In order to cope with such a situation, the applicant of the present invention is abundant in the world, and it is difficult to even dispose of it by re-producing it every year and discarding it. Patent application for a laminated material using a straight part of a plant stem of the family and a manufacturing method thereof (Japanese Patent Laid-Open No. 4-35702)
3). The method described in JP-A-4-357023 is
A grass stem is compressed to make a crack in the skin, impregnated with a curable resin by heating, and then dried. This is a method in which a plurality of the dried stems are arranged in parallel to each other to form a plurality of sheet-like materials, an adhesive is applied to these sheet-like materials, and then hot pressing is performed with a hot press to obtain a laminated material.

[0005]

In the method described in the above publication, in order to suppress swelling of the obtained laminated material due to water absorption or moisture absorption, a resin which is hardened by heating is used, and this resin is sufficiently used in the thermocompression molding step. Had to be cured. However, because the plant stem of the grass family itself has poor thermal conductivity, unless the heat pressing time by hot pressing is relatively long, it does not have a predetermined size and shape, resulting in poor productivity and increased energy consumption. There was a problem to do.

An object of the present invention is to provide a laminated material and a manufacturing method thereof, which have a short thermocompression molding time, are suitable for mass production, can be manufactured at low cost, have high mechanical strength and dimensional stability, and are versatile in use. It is in.

[0007]

In order to achieve the above object, as shown in FIGS. 1 to 10, the first method for producing a laminated material of the present invention is a skin portion 10 mainly composed of lignocellulose.
a and the plant portion 10 of a straight portion having a porous pulp portion 10b or a cavity are compressed to generate a crack 13 in the skin portion 10a or cut in the fiber direction and divided into a plurality, and the heat-curable liquid 14 is compressed. Alternatively, the divided plant stems are impregnated, and the heat-curing liquid impregnated into the plant stems is dried, and a plurality of the plant stems 20 dried by the heat-curing liquid are arranged in parallel with each other to form a sheet-like material 30. After stacking the sheet-like materials 30 of 1. to form a laminated body 40, the laminated body 40 is heated, and when the pressure reaches a predetermined pressure, steam or gas heated under pressure is jetted to heat the laminated body. This is a method of pressure molding.

In the second production method of the present invention, in order to improve the permeability of the adhesive, the plant stems compressed or divided by the first production method are not impregnated with the heat-curing liquid as necessary. , A method in which a plurality of plant stems are arranged in parallel to each other to form a sheet-like material 30, an adhesive agent is applied to the sheet-like material 30, these are laminated to form a laminate 40, and then thermocompression molding is performed. is there. The third production method of the present invention comprises impregnating a plant stalk compressed or divided by the first production method with a heat-curing liquid, followed by drying, and the heat-curing liquid arranges a plurality of dried plant stalks in parallel with each other. Then, the sheet-like material 30 is formed, then an adhesive is applied, these are laminated to form a laminate 40, and then thermocompression molding is performed.

A fourth production method of the present invention is to impregnate the plant stem compressed or divided by the first production method with a heat-curing liquid,
Subsequently, an adhesive is applied and dried, and a plurality of the heat-cured liquid and the plant stalk dried with the adhesive are arranged in parallel with each other to form a sheet-like material 30. Hereinafter, without applying the adhesive, a plurality of sheets are formed. After forming the laminated body 40 by laminating the sheet-like materials 30, when the pressure reaches a predetermined pressure, steam heated under pressure is injected to thermoform the laminated body. is there. As shown in FIGS. 11 to 15, according to the fifth manufacturing method of the present invention, the sheet-like material 30 formed by the first to fourth manufacturing methods is combined with one or more plate-like materials 32.
Are laminated to form a laminated body 42, and then the laminated body 42
Is applied, and when the pressure reaches a predetermined pressure, steam or gas heated under pressure is jetted to thermoform the laminate.

The present invention will be described in detail below. (a) Starting Material As shown in FIG. 3, the material used for the laminated material of the present invention has a skin portion 10a mainly made of lignocellulose and a porous pulp portion 10b at the core or a cavity (not shown). It is the plant stem 10 of the structure. The stems of high-grade corn, corn and sugar cane are typical examples. Besides this,
It is also possible to use the stems of other gramineous plants with knots, such as rice, wheat, reeds and the like. In particular, by utilizing the portion having the node, there is an effect that unevenness is generated in the laminated body, and steam or gas injected at the time of thermocompression molding easily penetrates into the laminated body.

As the plant stem, a straight line portion obtained by cutting off a leaf or a hakama portion is used as a round stem, or is cut open in the fiber direction or divided into a plurality of pieces. In the present invention, since the fiber of the plant stem is used without being cut into strips, it is lighter than conventional bagasse boards and straw boards, which are obtained by cutting the plant stem into strips and forming a board. A laminated material having an extremely high bending strength is obtained. The above effect obtained by using the knotted plant stem does not change even when the plant stem is cut in the fiber direction or divided into a plurality of parts. Before being impregnated with the heat-curing liquid, the plant stem 10 is not cut open as shown in FIG. 4 but compressed as it is by the compression rollers 11, 12 or the like to generate a crack 13 in the skin portion, or a plant (not shown). If the stem is cut open in the fiber direction or divided into multiple pieces, the thermosetting liquid permeates the inside of the plant stem in an extremely short time during impregnation.
Further, the stem itself becomes soft and a layer without gaps is easily formed when thermocompression-molded, which is preferable. Physical properties such as mechanical strength and dimensional stability of the laminated material laminated with the cracks are not inferior to those without the cracks.

Although the laminated material of the present invention can be composed of only the plant stem 10 as in the laminated materials obtained by the first to fourth manufacturing methods, the laminated material obtained by the fifth manufacturing method is As described above, the plant stem and the plate-like material may be combined. As the plate-like material, wood veneer, sawn wood, laminated wood, plywood, particle board, hard board, insulation board, MDF (Medium Density Fiber B)
oard), LVL (Laminated Veneer Lumber), lumber board, corrugated board and other woody plate materials; iron plate, galvanized steel plate, painted steel plate, stainless steel plate, aluminum plate, copper plate, lead plate and other metal plates; silicic acid Inorganic plate-shaped materials such as calcium plate, wood wool cement plate, asbestos cement plate, gypsum board; vinyl chloride resin, acrylic resin, styrene resin, ABS resin, AS resin, phenol resin, melamine resin, urea resin, polyethylene, A plate material made of synthetic resin such as polypropylene is used. In addition to a flat plate having a flat surface, a plate having a corrugated surface such as a corrugated plate or a keystone plate, a foam plate, or a mesh plate may be used as the plate-like object.

(B) Heat-curing liquid In the first, third, fourth, and fifth manufacturing methods except for the second manufacturing method of the present invention, as shown in FIG. 5, compressed or divided plants are used. The stem 10 is impregnated with the thermosetting liquid 14. This heat-curing liquid is a liquid substance containing a formaldehyde-based resin as a main component, which hardens the plant stem by heating. Specific examples include the following. (i) One or more mixtures or co-condensates selected from formaldehyde resins such as urea resins, melamine resins, phenol resins, resorcinol resins, tannin resins and lignocellulose liquefied resins. (ii) Compounds obtained by modifying these mixtures or cocondensates with water-soluble polymers such as polyvinyl alcohol, sodium polyacrylate, starch and cellulose derivatives. (iii) A mixture obtained by adding a thermoplastic resin emulsion containing a polyvinyl acetate resin and its derivative, a polyacrylic ester resin and its derivative, etc. to the above mixture or cocondensate. (iv) A mixture obtained by further adding a synthetic rubber latex containing styrene / butadiene rubber, allyl nitrile / butadiene rubber, isoprene rubber or the like to the above mixture or cocondensate.

(C) Impregnation of Heat-Curing Liquid When the plant stem is impregnated with the heat-curing liquid, the heat-curing liquid is preferably impregnated in an amount of 5 to 200% by weight based on the total dry weight of the plant stem. By compressing the plant stem in advance and forming fine cracks, or by dividing it into a plurality of pieces, the heat-curing liquid sufficiently impregnates the plant stem at room temperature and atmospheric pressure. You may impregnate it by pressurizing or depressurizing.

In order to strengthen the laminated material, the impregnation amount of the heat-curing liquid is preferably 5% by weight or more, but may be less than 5% by weight when the adhesive agent described later is applied. If the coating amount of the adhesive is small and the impregnation amount is less than 5% by weight, the plant stem may swell when the laminated material is used and the dimensional stability may decrease. On the other hand, if it exceeds 200% by weight, impregnation becomes difficult, and even if forced impregnation is performed by an operation such as pressure injection, the strength of the laminated material is not further improved. As shown in FIG. 6, in order to remove the surplus heat-curing liquid, the plant stem impregnated with the heat-curing liquid is squeezed roll 1
It is preferable to leave the plant stem 20 impregnated with a desired amount through 6 and 17.

(D) Formation of Sheet-like Material As shown in FIG. 2, when impregnated with the heat-curing liquid, the plant stems are dried at room temperature to 200 ° C., and then a plurality of plant stems 20 are arranged in parallel with each other. When not impregnated with the heat-curing liquid, a plurality of compressed or divided plant stems 10 are also arranged in parallel with each other to form a sheet-like material 30. When forming the sheet-like material 30, the ends of all the arranged stems are bound with a thread 21 so as not to disperse the plant stems, or temporarily fixed with an adhesive tape or a rewetting tape (not shown), or a thread-like shape. Alternatively, apply an adhesive in a band shape to bind all the stems together.

(E) Application of Adhesive In the second to fifth methods of the present invention, an adhesive is used to bond sheet-like materials to each other or sheet-like materials to plate-like materials. It When only the adhesive is used without using the heat-curing liquid as in the second production method of the present invention, examples of the adhesive include urea resin, melamine-urea co-condensation resin, and phenol-melamine resin. Thermosetting resin that cures by heating, such as phenol resin, phenol-resorcinol resin, resorcinol resin, epoxy resin, urethane resin, furfural resin, isocyanate-based resin containing aqueous polymer isocyanate, tannin resin, lignocellulose liquefied resin Is preferably used. Particularly preferable adhesives are those mentioned above.
The same as (i) to (iv) can be mentioned.

When an adhesive is further used in addition to the heat-curing liquid as in the third production method of the present invention, the adhesive may be polyvinyl chloride in addition to the thermosetting resin described above. , A resin solution prepared by dissolving a thermoplastic resin such as polyvinyl acetate, acrylic resin, polystyrene, polyvinyl alcohol, nylon, polyamide resin, etc. in a solvent, natural rubber, synthetic rubber, or a mixture of one or more of these. Can also be used. Further, as in the fourth production method of the present invention, after impregnating the plant stalk with the heat-curing liquid, before forming the sheet-like material, when an adhesive is applied and dried, under certain conditions. A thermosetting resin that can be dried without proceeding the curing reaction is used.
Specific examples include the same as (i) to (iv) described above.

In the case of the fourth manufacturing method, if the heat-curing liquid contains a formaldehyde resin containing a low molecular weight component as a main component, the heat-curing liquid may be impregnated without further application of the adhesive. Good. Examples of the heat-curing liquid containing the low-molecular-weight component formaldehyde resin include a heat-curing liquid in which a low-molecular-weight formaldehyde resin having a molecular weight of 600 or less and a high-molecular-weight formaldehyde resin having a molecular weight of 1000 or more coexist. To be Secondly, a mixture liquid of a low molecular weight component formaldehyde resin having a molecular weight of 600 or less and one or both of a high molecular weight water-soluble polymer and a thermoplastic resin emulsion can be mentioned. The reason why the application of the adhesive can be omitted by impregnating the heat-curing liquid containing the low molecular weight formaldehyde resin is that the low molecular weight formaldehyde resin penetrates the pith of the plant stem and the fragile part It also reinforces and the high molecular weight component remains on the surface of the plant stem to act as an adhesive.

When the adhesive is applied only in the fourth manufacturing method, it is dried after the application and before forming the sheet-like material. This drying is preferably carried out by leaving it to stand for about 3 days or by drying in the sun. When shortening the drying time, artificial drying is performed after sun drying. When not only the above natural drying but all artificial drying, the drying temperature is 30 to 150 ° C., preferably 50 to 100 ° C., where curing of the adhesive is difficult to proceed. The higher the drying temperature, the shorter the drying time, and it is necessary to prevent overdrying. The fourth manufacturing method can be immediately transferred to the laminating step after the sheet-like material is formed, and is excellent in productivity. In the first to third manufacturing methods other than the fourth manufacturing method, after applying the adhesive, the sheet-shaped materials are laminated with each other or the sheet-shaped material and the plate-shaped material are laminated while the adhesive is not dried.

Any of the adhesives may contain, in addition to the above components, one or both of a filler and a filler.
Examples of the filler include wheat flour, barley flour, rice flour, defatted soybean flour, corn gluten powder, blood flour, and the like, and fillers include clay, talc, calcium carbonate, wood powder, titanium oxide powder, walnut shell powder, and chaff. Powder, coconut shell powder, etc. are mentioned. The amount of adhesive used varies depending on the type of adhesive or the type and shape of the plant stem, but in general
20 to 500 g per square meter. When the amount of the adhesive used is less than 20 g, the mechanical strength of the laminated material is remarkably lowered, and when the amount of the adhesive used is more than 500 g, the cost is remarkably increased as compared with the performance of the laminated material.

(F) Formation of Laminated Body The method of laminating the sheet-shaped materials or the sheet-shaped material and the plate-shaped material by stacking them is appropriately determined according to the purpose of use of the laminated material. When making a laminated body of sheet-like materials, the plant stems 20 configured as shown in FIG. 2 cross each sheet-like material in order to have a uniform bending strength in all directions and prevent warpage of the laminated material. Thus, a laminated body 40 is formed by laminating a plurality of sheet materials 30. Further, when the bending strength in a specific direction is made extremely high, the plant stem 20 configured as shown in FIG.
To form a laminated body 40 in which a plurality of sheet-like materials 30 are laminated so that they are in the same direction. As shown in FIG. 8, the plant stems forming part of the sheet-shaped material 30 are replaced with other sheet-shaped materials 3
It is also possible to form a laminated body 40 that intersects with the plant stem that constitutes 0.

A laminated body 42 composed of the sheet-like material 30 and the plate-like material 32.
When making a sheet, a plate-like object 32 joined to the sheet-like object 30
Depending on the application of the laminated material, one side or sheet
3 and laminated on both sides as shown in FIG. It is preferable that the plate-shaped material is used as the surface material and the sheet-shaped material is used as the core material. However, when the design of the sheet-shaped material is to be utilized, the plate-shaped material is laminated only on one surface of the sheet-shaped material. Alternatively, for reinforcement, a plate-shaped material may be inserted as an intermediate layer of a laminated body of a large number of sheet-shaped materials. When a material having both mechanical strength and directionality such as a veneer is used as the plate-shaped material, the sheet-shaped material is laminated so that the fiber direction of the plant stem and the fiber direction of the veneer are orthogonal to each other. Is desirable.

(G) Thermocompression molding of laminated body Laminated body 40 composed of a plurality of sheet-like materials 30 (FIGS. 7 to 9) or laminated body 42 composed of a sheet-shaped material 30 and a plate-shaped material 32 (FIG. 14). Is subjected to temporary compression if necessary, and is integrally molded using a hot press under the injection of steam or gas pressurized and heated. Hot press temperature is 50 ~
In the range of 250 ° C., the pressure is preferably in the range of ^{2 to} 30 kg / cm ² . By controlling this pressure, the density of the obtained laminated material can be changed. The pressure of steam or gas to be injected is in the range of 1 to 10 kg / cm ² , and the temperature is 50.
It is preferably in the range of to 450 ° C. The gas of the present invention includes an inert gas such as nitrogen gas and carbon dioxide gas, or air. As the hot press of the present invention, when the laminated body is composed of only sheet-like materials, the hot press 70 shown in FIGS. 1 and 2 is used, and a metal plate serving as a backing plate for the upper and lower surfaces of the laminated body is used. When 81 is used or when the upper and lower surfaces of the laminated body are plate-like objects, the hot press 80 shown in FIGS. 11 and 12 is used.

That is, as shown in FIGS. 1 and 2, when the laminated material is made of only the sheet-like material 30, the hot press 7 is used.
A large number of injection holes 73a and 74a for injecting pressurized steam or gas are provided on the upper and lower hot plates 73 and 74 of 0,
The spacer 75 for controlling the thickness of the laminated material is provided in the laminated body 4
The spacer 75 is arranged so as to surround 0, and the spacer 75 is also provided with a large number of similar injection holes 75a. Hereinafter, steam will be described as a representative of the injected gas. In FIG. 1, the spacer 75 is fixed to the lower heating plate 74. The steam pipe 7 is in the injection hole 73a.
3b, and the steam pipe 74b is connected to the injection holes 74a and 75a, respectively. The steam pipes 73b and 74b are provided with open / close valves 73c and 74c, which are electromagnetic valves.
Further, steam pipes 73d and 74d for heating the heating plates 73 and 74 are arranged in a meandering manner. These steam pipes 73d and 74d are provided with inlet valves 73e and 74e and outlet valves 73f and 74f, which are electromagnetic valves.

On the other hand, as shown in FIG. 11, when the metal plate 81 is used, or when the plate-like material 32 is arranged on the upper and lower surfaces of the laminated body 42, the hot plates 83 and 84 of the hot press 80 have injection holes. Since the injection hole is closed by the metal plate 81 or the plate-shaped object 32 even if the above is provided, and unnecessary vapor drain drops from the injection hole to the plate-shaped object to attach stain stains or the like to the surface of the laminated material,
As shown in FIGS. 11 and 12, a rectangular frame-shaped spacer 8
Only 5 is provided with a large number of injection holes 85a. In FIG. 11, the spacer 85 is fixed to the upper heating plate 83. A steam pipe 83b is communicatively connected to the injection hole 85a. The steam pipe 83b is provided with an opening / closing valve 83c which is an electromagnetic valve. Hot plate 83,
Inside 84, steam pipes 83d and 84 for heating them are provided.
d meanders and is respectively piped. These steam pipes 83
Although not shown, d and 84d are provided with an inlet valve and an outlet valve which are electromagnetic valves as in FIG. When manufacturing a thick laminated material, spacers may be provided on both the upper and lower hot plates (not shown).

In both hot presses 70 and 80, since the steam is effectively used at the timing of injecting steam from the injection holes, the hot plate of the hot press is brought into close contact with the laminated body, and the pressing force reaches a predetermined value. The injection time is selected from the range of several seconds to several minutes depending on the thickness of the laminate and the presence / absence of the plate-like material. After the thermocompression molding, the plate-like laminated material 50 shown in FIG. 10 or the plate-like laminated material 60 shown in FIG.

When the steam or gas heated under pressure is injected into the laminate under thermocompression molding, if the laminate is strongly compressed, the composition becomes dense and the voids inside the laminate are reduced, so that the vapor or gas is laminated. Penetration into the body is significantly reduced. The laminated material of the present invention cannot have a density of at least 0.2 g / cm ³ or less, but if it has a high density of 0.6 g / cm ³ or more, the efficiency of jet heating decreases. Therefore, 0.2 to 0.6 g / cm ³
In the density range of, the laminated material with the highest jet heating efficiency can be obtained. Many ordinary laminated materials have a thickness of 15 mm or less. When manufacturing a laminated material having a thickness of 15 mm or more, first, a thin laminated material is prepared, and a method of re-laminating a plurality of thin laminated materials is adopted. Has been done. According to the method of the present invention, a laminated material having a thickness of 15 mm or more can be laminated with a single hot pressing, so that the production efficiency is remarkably improved. However, in the case of manufacturing a laminated material having a thickness of 200 mm or more, the thickness of the laminated body before hot pressing becomes too large, and unless the stroke interval of the hot press is widened, it becomes difficult to carry out the hot pressing, which is inevitable. As a result, the volume of the hot press will increase and the equipment cost will increase. Therefore, the thickness of the laminated material is preferably 15 to 200 mm. When such a thick laminate is hot-pressed in one shot, the compressibility of the central layer is reduced, and the overall density is 0.2
It falls within the range of to 0.6 g / cm ³ .

[0029]

When the steam or gas heated under pressure is jetted from the side surface of the laminate during thermocompression molding, the jetted steam or gas is discharged from the porous pulp portion exposed on the side surface of the laminate or into the cavity. It penetrates easily and the plant stems quickly plasticize, compress more flatly and form in a short time. This steam injection causes hydrolysis or thermal decomposition of the hemicellulose component or sugar component contained in the lignocellulosic material, particularly by steam injection, so that the relaxation rate of internal stress of the laminate is faster than that of thermocompression molding without steam injection. That is, the dimensional stability of the obtained laminated material is improved.

If it is impregnated with a heat-curing liquid or an adhesive is applied, the heat-curing liquid or the adhesive is cured by steam injection to have a desired strength and more excellent dimensional stability. A laminated material is obtained. If the heat-curing liquid or the adhesive contains a formaldehyde resin as its main component, the formaldehyde resin forms an acetal bond with the hydroxyl group of the hydrophilic component contained in the plant stem, and the resulting laminated material has strong water resistance and mechanical strength. Gives high strength to. Further, since the formaldehyde resin is water-based, does not contain a solvent such as polyester resin, and has no risk of fire, it is not necessary to make the laminated material manufacturing apparatus explosion-proof and the facility cost is low.

[0031]

As described above, as compared with the conventional method for producing a laminated material using plant stems, the method for producing a laminated material of the present invention significantly shortens the thermocompression molding time by injecting steam or gas. Therefore, the productivity can be remarkably improved. Therefore, it is possible to produce the plant stem, which is a resource-rich and inexpensive raw material, with a small amount of energy, and thus it is possible to further reduce the production cost. In particular, the produced laminated material has an internal stress of the laminated body relieved by the injection of steam or gas, and the plasticization of the plant stem is promoted. Has little swelling with water and high dimensional stability.

The density of the laminated material of the present invention is preferably in the range of 0.3 to 0.7 g / cm ³ , which makes it extremely lightweight as compared with the currently marketed plywood, particle board, fiber board and the like. On the other hand, the mechanical strength represented by the bending strength and the dimensional stability of the laminated material are higher than those of the particle board and the fiber board, and are the same as those of plywood. As a result, the laminated material of the present invention is used as a flooring material, a roofing material, a wall material, a concrete form material, and the like as a building material equivalent to a conventional plywood, particle board, fiber board, and furniture material. It can be widely used as a skin panel for furniture panels, table materials, shelf board materials, and doors and door cores. Further, when a plate-like material made of a metal material or an inorganic material is provided on the surface of the laminated material, it is possible to add functions such as fireproofness, sound insulation, heat insulation and electromagnetic insulation. Furthermore, by weakening the press pressure during thermocompression molding to reduce the density of the laminated material, it can also be used for heat insulating materials or sound absorbing materials, and by selecting various mold shapes during thermocompression molding, It is possible to manufacture a laminated material having an arbitrary shape such as a curved plate, a corrugated plate, a prism, a round pillar, etc. By these, various building materials and furniture materials can be obtained.

[0033]

Embodiments of the present invention will now be described in detail with reference to the drawings together with comparative examples. <Example 1> As shown in FIG. 4, the straight part of the high-yam stem 10 cut to a length of 35 cm is not cut open and is left as a round stem, with an interval of about 60% of the diameter of the high-yam stem. It was compressed by passing it between a pair of pinch rollers 11 and 12 holding the soybeans, and fine splits 13 were formed in the skin portion 10a of the stem 10. As shown in FIG. 5, the high stalk 10 provided with the cracks 13 was dipped in a 10% aqueous solution 14 of a phenol resin (“XL-481” manufactured by Mitsui Toatsu Chemicals) for 5 minutes. As a result, the phenol resin aqueous solution penetrated not only into the skin portion 10a of the stem but also into the pulp portion 10b through the cracks 13. As shown in FIG. 6, the high-yarn stalk 10 impregnated with the aqueous phenol resin solution is passed between a pair of squeezing rolls 16 and 17 which maintain an interval of about 60% of the diameter of the stalk to remove excess phenol. The aqueous resin solution was removed and dried at room temperature for 3 days to obtain high stalk 20 impregnated with 21.2% of phenol resin.

As shown in FIGS. 13 and 14, 22 pieces of high-yarn stems 10 are arranged in parallel and closely to each other, and the ends of the stems are bundled with a thread 21 to form a sheet-like material 30 having a width of about 35 cm.
3 were prepared. Next, 5 sheets of isocyanate resin (KRS-12X manufactured by Koyo Sangyo Co., Ltd.) was formed on both surfaces of the three sheet-like materials 30.
After applying 20 g each of the adhesive prepared by adding 30 parts by weight of clay to 100 parts by weight of 0% aqueous dispersion using a roll, the high stalks to be formed should be orthogonal to each other in sheet form. The sheet-like materials were superposed on each other to prepare a three-layer laminate. Then, 1.5 mm-thick radiatapine single plates 32, 32 corresponding to plate-like materials were superposed on both front and back surfaces of this three-layer laminate to prepare a laminate 42 consisting of a total of five layers.

As shown in FIG. 11, the metal plate 81 was placed on the hot plate 84 under the hot press 80, and the laminate 42 was placed thereon. Another metal plate 81 was placed on the laminated body 42, and the laminated body 42 was thermocompression-molded by the upper thermal plate 83 and the lower thermal plate 84 each having the spacer 85 having a thickness of 20 mm. As shown in detail in FIG. 12, the spacer 85 has a rectangular frame shape, and a large number of fine vapor injection holes 85a are formed on the inner surface thereof at intervals of 15 mm. While maintaining the hot plates 83 and 84 of the hot press 80 at a temperature of 160 ° C., the laminated body 42 is compressed, and the surface pressure of the laminated body is 9 kg / cm.
^When it reaches ² , the on-off valve 83c opens and immediately 6 kg / c
Live steam with a pressure of m ² was injected for 30 seconds. Vapor easily penetrated into the laminated body placed in a space sealed by the spacer and the upper and lower heating plates from the porous pulp portion exposed on the side surface. This heat and pressure was further continued for 1 minute and 30 seconds to obtain a plate-shaped laminated plate 60 (FIG. 15) having a thickness of 20 mm. The physical properties of the obtained laminated board were tested by the method specified in JIS A5908 (particle board). The results are shown in Table 1.
Shown in. In Table 1, "thickness swelling ratio" refers to the thickness swelling ratio after boiling for 2 hours.

<Comparative Example 1> In Example 1, the on-off valve 8
A laminated plate having a thickness of 20 mm was obtained in the same manner as in Example 1 except that 3c was closed and thermoforming was performed under the following conditions. That is, in Comparative Example 1, the pressurized and heated live steam was not injected.
With this hot press, at a temperature of 150 ° C, 9 kg / c
Thermocompression molding was performed at a pressure of m ² for 20 minutes. The physical properties of the obtained laminate were tested by the same method as in Example 1. The results are shown in Table 1.

<Example 2> 20 g of each adhesive prepared by adding 25 parts by weight of wheat flour to 100 parts by weight of a 50% aqueous dispersion of an isocyanate resin (KRS-12X manufactured by Koyo Sangyo Co., Ltd.) was used to roll 3 parts each. The same material as in Example 1 was used, except that the same material as in Example 1 was used, except that it was applied to both sides of a sheet of sheet-like material, live steam was sprayed for 3 minutes, and thermocompression was continued for 30 seconds. A laminated board having a thickness of 20 mm was obtained by the above method. The physical properties of the obtained laminate were tested by the same method as in Example 1. The results are shown in Table 1.

<Comparative Example 2> In Example 2, the on-off valve 8
A laminated plate having a thickness of 20 mm was obtained in the same manner as in Example 2 except that 3c was closed and thermoforming was performed under the following conditions. That is, in Comparative Example 2, the pressurized and heated live steam was not injected.
With this hot press, at a temperature of 150 ° C, 9 kg / c
Thermocompression molding was performed at a pressure of m ² for 20 minutes. The physical properties of the obtained laminate were tested by the same method as in Example 1. The results are shown in Table 1.

<Example 3> The surface of the straight part of the reed stalk cut to a length of 35 cm was lightly ground with an abrasive cloth, and then cut in the fiber direction and divided into two pieces, 55 pieces parallel to each other and closely Arrange and tie the stem ends with a thread, width of about 35 cm
3 sheet-like products were prepared. Next, 100 parts by weight of high molecular weight phenolic resin and flour 3 on both sides of the three sheets.
0 parts by weight and diphenylmethane diisocyanate (MD
20 g of each adhesive obtained by adding and mixing 10 parts by weight of the prepolymer of I) was applied using a roll. The high molecular weight phenolic resin has a viscosity of 2.5 poise at 25 ° C., a pH of 11.5, and a concentration of 40%. As described above, in addition to the three sheet-like materials whose both surfaces were coated with the adhesive, four pieces of 4.2 mm-thick Southern Ocean veneer were prepared. One of the above-mentioned sheet-like materials was laminated on one of the South Sea material veneers so that the fiber directions of both were the same. Laminate the veneers in the same manner, stack the second sheet-like material on the second sheet of the Southern Ocean wood in the same manner, and place the third sheet of the Southern Ocean material on the second sheet-like material. Laminate the boards in the same manner, then laminate the third sheet-like material on this third piece of Southern Ocean material in the same manner, and finally, on the third sheet-like material, the fourth piece of Southern Ocean material. The single plates were laminated in the same manner to produce a laminated body having a 7-layer structure.

A thickness of 3 instead of a 20 mm thick spacer
A hot press substantially the same as in Example 1 was prepared except that a 0 mm spacer was used, and the laminated body consisting of the above 7 layers was put in this hot press and the temperature was raised to 160 ° C. While maintaining, pressure heating was performed until the pressure reached 9 kg / cm ² . As soon as the pressure reached 9 kg / cm ² , 1 kg of live steam with a pressure of 6 kg / cm ²
Spray for 30 minutes, continue heat and pressure for 3 minutes, thickness 30mm
Thus, a laminated plate was obtained in which the fiber directions were all parallel to each other. The physical properties of the obtained laminate were tested by the same method as in Example 1. The results are shown in Table 1. When the temperature change in the central layer was measured during the hot pressing, the temperature reached 160 ° C. in about 5 seconds.

Comparative Example 3 Substantially the same as Example 3 except that three sheets of 2.4 mm thick Southern Ocean timber were used in place of the three sheets of reed stalks. 7 in the same way
A laminated body having a layered structure was produced and molded under the same heat and pressure conditions as in Example 3. The obtained plate-shaped laminated material has a density of 0.58 g / cm.
^{Was 3} . As a result, the temperature of the central layer during hot pressing remains 8 even after the end of hot pressing for 4 minutes including the steam injection time.
It did not reach 0 ° C., and it was revealed that the adhesion of the laminate was insufficient under the hot pressing conditions of Example 3.

Example 4 After straightly sanding a straight portion of corn stalk cut to a length of 35 cm, the corn stalk was kept in a state of being a round stalk without being cut open, and an interval of about 60% of the diameter of the corn stalk was maintained. It was compressed by passing it between a pair of pinch rollers, and fine cracks were formed in the bark of the stem. This processed corn stalk is a phenolic resin containing a low molecular weight component (Mitsui Toatsu Kagaku: “X
L-481 ") 70 parts by weight and 30 parts by weight of the high molecular weight phenolic resin used in Example 3 were mixed and immersed in a heat-curing solution prepared to have a concentration of 35% for 5 minutes, and then dried at room temperature for 3 days, A stalk having a phenol resin impregnation rate of about 40.2% and a water content of about 18% was prepared. 2 this cornstalk
0 pieces of them were arranged in parallel and closely to each other, and the ends of the stems were bound with a thread to prepare three sheet-like materials having a width of about 35 cm.

Next, three sheet-like materials are superposed on each of the sheet-like materials so that the respective fiber directions are orthogonal to each other, and a thickness of 1.8 m, which corresponds to a plate-like material, is formed on both front and back surfaces of the three-layer laminate.
Radiata pine veneers of m were laminated so that the fiber direction thereof was orthogonal to the fiber direction of the cornstalk, to prepare a laminate having a total of 5 layers. The laminated body consisting of the above five layers was put in the same hot press as in Example 1 and the temperature was raised to 150.
While maintaining the temperature at 0 ° C., pressure heating was performed until the pressure reached 9 kg / cm ² . Immediately after the pressure reaches 9 kg / cm ² , live steam having a pressure of 6 kg / cm ² is jetted for 15 seconds, and the thermal pressure is continued for 4 minutes and 45 seconds to obtain a thickness of 20 mm.
A laminated plate of was obtained. The physical properties of the obtained laminate were tested by the same method as in Example 1. The results are shown in Table 1.

[0044]

[Table 1]

As is clear from Table 1, the hot pressing times of Examples 1 and 2 were significantly shorter than those of Comparative Examples 1 and 2, and the mechanical strength and dimensional stability were excellent. It was Further, in Example 3, a material suitable for a step board of a staircase and in Example 4 a material suitable for a shelf board could be obtained in an extremely short hot pressing time.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a hot press for thermocompressing a laminated body including only the sheet-like material of the present invention.

FIG. 2 is a perspective view of the hot press.

FIG. 3 is a perspective view of a plant stem that is a starting material for the laminated material of the present invention.

FIG. 4 is a perspective view of a compression roller that compresses the plant stem to generate cracks in the skin.

FIG. 5 is a diagram in which a plant stem is impregnated with a thermosetting liquid.

FIG. 6 is a side view of a squeezing roller that removes excess heat-curing liquid from the impregnated plant stem.

FIG. 7 is a side view of a laminated body in which a plurality of sheet-shaped materials are laminated with all the plant stems arranged in the same direction.

FIG. 8 is a side view of a laminated body in which a plurality of sheet-shaped materials are stacked with a part of the sheet-shaped materials arranged so that the arrangement direction of the plant stems is different from the arrangement direction of the plant stems of another sheet-shaped material.

FIG. 9 is a side view of a laminated body in which a plurality of sheet-shaped materials are laminated such that the arrangement directions of the plant stems intersect each sheet-shaped material.

10 is a perspective view of the plate-shaped laminated material after the thermocompression molding of FIG.

FIG. 11 is a cross-sectional view of a hot press for thermocompressing a laminate in which plate-like materials are laminated on both surfaces of the laminated sheet-like material of the present invention.

FIG. 12 is a view of the upper hot plate of the hot press viewed from the lower hot plate.

FIG. 13 is a perspective view showing a state in which a plurality of sheet-shaped materials are stacked such that the arrangement directions of the plant stems of the sheet-shaped materials intersect each other and the plate-shaped materials are stacked on both upper and lower surfaces thereof.

FIG. 14 is a side view of a laminate in which plate-like materials are laminated on both sides of the stacked sheet-like materials.

FIG. 15 is a perspective view of the plate-shaped laminated material after the thermocompression molding of FIG. 11.

[Explanation of symbols]

 10 Plant Stem 10a Skin Part 10b Pithal Part 13 Crack 14 Heat-curing Liquid 20 Impregnated and Dehydrated Plant Stem 30 Sheet-like Material 32 Plate-like Material 40,42 Laminate 50,60 Plate-like Laminating Material 70,80 Hot Press 73,74 , 83, 84 Heat plate 75, 85 Spacer 73a, 74a, 75a, 85a Injection hole 81 Metal plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Shinji Tanzawa, Shinji Tanzawa 2324-2 Mita, Tama-ku, Kawasaki-shi, Kanagawa 204 Grace Mita 204 (72) Hideichi Kawai 70-35, Fukakusa-taniguchi-cho, Fushimi-ku, Kyoto

Claims (13)

[Claims] 1. A skin portion (10) mainly composed of lignocellulose
a) and a porous stem (10b) or a straight portion of the plant stem (10) having a cavity is compressed to generate a split (13) in the skin (10a) or a plurality of them are cut in the fiber direction. A step of dividing, a step of impregnating the compressed or divided plant stem with a heat-curing liquid (14), a step of drying the heat-curing liquid impregnated in the plant stem, and a plant stem in which the heat-curing liquid is dried A step of arranging a plurality of (20) in parallel with each other to form a sheet-like material (30); a step of laminating a plurality of sheet-like materials (30) to form a laminate (40); 40), and when the pressure reaches a predetermined pressure, steam or gas heated under pressure is injected to thermoform the laminate to produce a laminated material. 2. A skin portion (10) mainly composed of lignocellulose
Sheet-like article (30) in which a plurality of linear plant stems (10) having a) and a porous pulp (10b) or a cavity are arranged in parallel with each other.
And a step of applying an adhesive to the sheet-like material (30), and a step of forming a laminate (40) by laminating a plurality of sheet-like materials (30) coated with the adhesive. A method for producing a laminated material, which comprises a step of pressurizing the laminated body (40) and injecting pressurized steam or gas when the pressure reaches a predetermined pressure to thermocompress the laminated body. 3. A skin portion (10) mainly composed of lignocellulose
a) and a porous stem (10b) or a straight portion of the plant stem (10) having a cavity is compressed to generate a split (13) in the skin (10a) or a plurality of them are cut in the fiber direction. A step of dividing, a step of impregnating the compressed or divided plant stem with a heat-curing liquid (14), a step of drying the heat-curing liquid impregnated in the plant stem, and a plant stem in which the heat-curing liquid is dried A step of arranging a plurality of (20) in parallel with each other to form a sheet-like material (30); a step of applying an adhesive to the sheet-like material (30); and a plurality of the sheet-like materials to which an adhesive is applied. A step of stacking the article (30) to form a laminate (40), and when the laminate (40) is pressurized and its pressure reaches a predetermined pressure, the pressurized steam or gas is injected to A method for producing a laminated material, which comprises a step of thermocompressing the laminated body. 4. A skin portion (10) mainly composed of lignocellulose
a) and a porous stem (10b) or a straight portion of the plant stem (10) having a cavity is compressed to generate a split (13) in the skin (10a) or a plurality of them are cut in the fiber direction. A step of dividing, a step of impregnating the heat-curing liquid (14) into the compressed or divided plant stalks, followed by applying an adhesive and drying, and a plurality of the plant stalks in which the heat-curing liquid and the adhesive are dried. The steps of arranging them in parallel with each other to form the sheet-like material (30), laminating a plurality of the sheet-like materials (30) to form a laminate (42), and adding the laminate (40). A method for producing a laminated material, comprising the steps of: pressurizing, and when the pressure reaches a predetermined pressure, injecting steam heated under pressure to thermocompress the laminated body. 5. The laminate (42) is formed by laminating one or more plate-like materials (32) together with the sheet-like material (30).
5. The method for manufacturing a laminated material according to any one of 4 to 4. 6. The method for producing a laminated material according to claim 1, wherein the plant stem (10) is impregnated with a thermosetting liquid (14) containing a formaldehyde resin and dried as it is to form a sheet (30). 7. The injection direction of the steam or gas heated under pressure to the laminate (40, 42) is the same direction as the arrangement direction of the plant stems (10) constituting the sheet-like material (30). Through 6
The method for manufacturing a laminated material according to any one of the above. 8. The method for producing a laminated material according to claim 7, wherein steam or gas heated under pressure is injected from spacers (75, 85) that regulate the thickness of the laminated material in the thermocompression molding step. 9. A laminated body (40, 42), wherein spacers (75, 85) are arranged so as to surround the laminated body (40, 42) in a thermocompression molding process and placed in a sealed space at the time of hot pressing. The method for producing a laminated material according to claim 8, wherein steam or gas heated under pressure is injected into the plate. 10. The temperature of the steam or gas heated under pressure is in the range of 50 to 450 ° C., and the temperature of the hot pressing is 50.
The method for producing a laminated material according to any one of claims 1 to 9, wherein the pressure is in the range of ² to 30 ° C and the pressure is in the range of ² to 30 kg / cm ² . 11. The method for producing a laminated material according to any one of claims 1 to 10, wherein the plant stem (10) is a gramineous stalk composed of high-grade corn, corn, sugar cane, rice, wheat or reed. 12. A laminated material having a density of 0.2 to 0.6 g / cm ³ produced by the method according to claim 1. 13. A laminated material having a thickness of 15 to 200 mm produced by the method according to claim 1.