JPH05116239A - Laminated material and its manufacture - Google Patents

Abstract

PURPOSE:To manufacture a laminated material of low manufacturing cost, high dynamic strength and dimension stability, light and little in swelling generated by water. CONSTITUTION:A coating material 22 is formed integrally with a sheet-shaped material 20 on one side of both faces of a simple sheet-shaped material 20 composed of a plurality of plant stems 10 having skin sections 10a composed mainly of lignocellulose and porous pith sections 10b disposed in parallel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light-weight laminate having excellent mechanical strength, which is mainly composed of grass stems such as high-grade corn, corn and sugar cane, and a method for producing the same. More specifically, laminates used for construction materials such as tatami floors, furniture materials, decoration materials, heat insulating materials, sound absorbing materials, display materials, various work materials, and base plates to which printed paper, PVC film, veneer, etc. are attached. The present invention relates to a material 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. The materials used for these applications all depend on wood resources and petroleum resources. The sawn timber and the plywood are wood itself and have high material strength and dimensional stability, but there is a problem that the utilization rate (yield) of wood is low because the parts having such characteristics are limited.

On the other hand, a particle board or a fiber board is formed by mixing wood chips or fibers with a synthetic resin adhesive and heat-curing the mixture 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 cut, 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, particle board and fiber board, which are used in large amounts for construction materials, etc., are mainly made of natural wood, and as a result of the recent depletion of wood resources, There is a limit to the amount of supply, and it will not be possible to sufficiently meet strong demand in the future, 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 the resin depends on petroleum resources, it is feared that the quantity will be secured in the future due to the problem of limited resources.

In order to cope with such a situation, the present applicant is abundant in the world, and it is difficult to even recycle it every year so that it is difficult to dispose of rice, such as rice, corn and sugar cane. 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. 63-1075
05, JP-A-1-280538). JP-A-63-107
The method described in Japanese Patent No. 505 is a technique in which a plant stem of Gramineae such as high-grade corn, corn, and sugar cane is cut in the fiber direction,
After performing core removal if necessary, rolling in a cut open state, a plurality of rolled stems are arranged in parallel with each other to form a sheet-like material, and after applying a known adhesive to the plurality of sheet-like materials, these are It is a method of laminating and pressure molding. In addition, JP-A-1
The method described in JP-A-280538 discloses a method of forming a flat stalk without cutting open the high stalk, or by flattening it by compression to form a flat stalk layer by arranging a plurality of flat stalks,
This is a method in which a known adhesive is applied to a plurality of flat stem layers, and then these are laminated and pressure-molded. The laminated material produced by these methods becomes a plate material having an arbitrary specific gravity, thickness and size, and has excellent performance in mechanical strength.

[0005]

The former method, however, provides extremely high mechanical strength and dimensional stability, but on the other hand, it involves many steps such as slitting, coring, and rolling of plant stems, and has a predetermined thickness. There is a problem that a large number of steps and a plant stem that is a raw material are required to obtain one laminated material, and the manufacturing cost becomes high. Further, the latter method, while the manufacturing cost is low, mechanical strength is not higher than the laminated material produced by the former method, and further, the laminated material is immersed in water, or if the laminated material contains water, There was a problem that the laminated material swelled and became thick. It is an object of the present invention to provide a laminated material which has a low manufacturing cost, has high mechanical strength and dimensional stability, is light in weight, has little swelling with water, and has a variety of uses, and a method for manufacturing the same.

[0006]

In order to achieve the above object, as shown in FIGS. 1 to 3, the laminated material 20 of the present invention comprises:
One side (FIG. 1) or both sides (FIG. 1) or both sides of a single sheet-like material 21 formed by arranging a plurality of plant stems 10 each having a skin portion 10a mainly composed of lignocellulose and a porous pulp portion 10b in parallel with each other. In 2), the covering material 22 is a laminated material integrally formed with the sheet-like material 21. The first method for producing the laminated material of the present invention is a skin part 1 mainly composed of lignocellulose.
0a and a plurality of plant stems 10 having a porous pulp portion 10b are arranged in parallel with each other to form a sheet-like material 21, and one or both surfaces of the sheet-like material 21 or one surface of the covering material 22 is coated with an adhesive. Then, the coating material 22 or the sheet-like material 21 is laminated on the coated surface of the adhesive, and the laminated body is formed. A second method for producing the laminated material of the present invention is a liquid compound, a resin liquid or a liquid compound capable of being polymerized into a plant stem 10 having a skin portion 10a mainly composed of lignocellulose and a porous pulp portion 10b. Is impregnated with a hardening liquid of the mixture of the above, and a plurality of the impregnated plant stems are arranged in parallel with each other to form a sheet-like material 21, and a covering material 22 is laminated on the sheet-like material to form this laminate. Then, the curing liquid is cured by heating. In the second manufacturing method, an adhesive is applied to one side or both sides of the sheet-like material 21, or an adhesive is applied to one side of the coating material 22, and then the coating material 22 or the sheet is applied to the application surface of the adhesive. Form 2
1 is preferably laminated.

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 is a plant stem 10 having a structure having a skin portion 10a mainly composed of lignocellulose and a porous pulp portion 10b on the core. Is. The stems of high-grade corn, corn and sugar cane are typical examples. Other than this, the stems of other grasses such as reeds, rice and mulberry can also be used. As for the plant stem, a straight line portion obtained by cutting off a leaf or a hakama portion is used as it is 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 a conventional bagasse board or straw board that is formed into a board by cutting the plant stem into strips. A laminated material having an extremely high bending strength is obtained. As a covering material integrally formed on one side or both sides of a single sheet-like material formed by arranging a plurality of plant stems in parallel with each other, wood veneer, plywood, particle board, hard board, insulation board , MDF
(Medium Density Fiber Board), LVL (Laminated
Veneer Lumber), lumber boards, wood materials such as corrugated board; iron plates, painted steel plates, stainless steel plates, aluminum plates, copper plates,
Inorganic materials such as lead silicate plate; calcium silicate board, wood wool cement board, asbestos cement board, gypsum board; vinyl chloride resin, acrylic resin, styrene resin, ABS resin, AS resin, phenol resin, melamine resin, Synthetic resins such as urea resin, polyethylene and polypropylene; rubbers such as natural rubber and synthetic rubber; or paper, synthetic paper, woven cloth, non-woven cloth and felt are 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, and a mesh plate may be used as the covering material.

(B) Hardening Liquid The plant stem of the present invention is preferably impregnated with a hardening liquid.
This hardening liquid is a liquid substance that hardens the plant stem by heating or by leaving it at room temperature, and is a liquid compound capable of polymerizing, a resin liquid, or a mixture thereof.
As the liquid compound capable of being polymerized, a polymerizable liquid monomer such as an acrylic acid ester monomer, a methyl methacrylate monomer, a styrene monomer or the like, and a high-molecular compound produced by subjecting these monomers to a condensation, polymerization or addition polymerization reaction. Liquid isocyanate compounds such as prepolymers that can be molecularized, tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, etc., or polymerization reactions such as liquefied liquids of furfural, furfuryl alcohol or lignocellulose , A liquid compound which can be polymerized by a condensation reaction or an addition condensation reaction. Here, the liquefied liquid of lignocellulose refers to a solution obtained by liquefying lignocellulose by adding phenols, polyols and the like to lignocellulose. This lignocellulosic liquefied liquid is, for example, of plant stems such as high stalks,
Leaves or hakama parts to be discarded, or curved stems or end pieces that are not suitable for use in the presence of phenols, etc.
It is prepared by melting at 300 ° C. under high temperature and high pressure of 1 to 100 atm. By using an acid catalyst such as sulfuric acid, hydrochloric acid, phenolsulfonic acid, or paratoluenesulfonic acid, 10
It becomes possible to dissolve at 0 to 200 ° C. under atmospheric pressure. Also,
The resin liquid includes unsaturated polyester resin, epoxy resin,
Liquid polymers such as phenolic resins, melamine resins, urea resins and the like and their prepolymers are generally mentioned. In addition to this, polyvinyl chloride, polyvinyl acetate,
Acrylic resin, polystyrene, polyvinyl alcohol,
It is also possible to use a resin solution prepared by dissolving a thermoplastic resin such as nylon or polyamide resin in a solvent, or a resinification liquid of lignocellulose. Here, the lignocellulosic resinification liquid refers to a resin liquid in which the lignocellulose liquefaction liquid is resinified with an aldecht compound, an isocyanate compound or the like and dissolved in water or a solvent.

(C) Impregnation of Hardening Liquid In the present invention, when the plant stem is impregnated with the hardening liquid, the hardening liquid is preferably impregnated in an amount of 5 to 200% by weight based on the total dry weight of the plant stem. Although the plant stem is sufficiently impregnated at room temperature and atmospheric pressure, the hardening liquid may be impregnated by specially heating or pressurizing or depressurizing. If the impregnated amount of the curable liquid exceeds 50% by weight, the curable liquid will seep out when laminating the sheet-like materials to cause an adhesive action, and the original amount of the adhesive used can be greatly reduced. When the curing liquid does not contain a high molecular weight component, the impregnation amount of the curing liquid must be 50% by weight or more, or an adhesive must be used. If the amount of the hardening liquid impregnated is less than 5% by weight, the strengthening effect of the laminated material, which is one of the purposes of impregnating the hardening liquid, cannot be sufficiently obtained, and the plant stem swells when the laminated material is used, and dimensional stability is obtained. There is a risk of deterioration in sex. 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.

(D) Formation of Sheet-like Material The sheet-like material is a straight stem that is not cut in the direction of the fiber but is left as a round stem, or is compressed to cause a crack in the skin, or a fiber is formed. After being cut open in the direction or divided into a plurality of pieces, a plurality of pieces are arranged in parallel with each other. When making a sheet-like material, the ends of all the arranged stems should be bound with a thread, temporarily fixed with an adhesive tape or rewetting tape, or glued in a thread-like or band-like manner so that each plant stem is not dispersed. To bind all the stems together.

(E) Bonding of Sheet-Shaped Material and Covering Material The coating material bonded to the sheet-shaped material is laminated on one side or both sides of the sheet-shaped material depending on the application of the laminated material. It is preferable to use the covering material as the surface material or the sheet-like material as the core material, but when the design of the sheet-like material is utilized, the coating material is laminated only on one surface of the sheet-like material. When using a material that has both mechanical strength and directionality such as veneer as the covering material, superimpose so that the fiber direction of the plant stem of the sheet material and the fiber direction of the veneer are orthogonal to each other. Is desirable.
When the plant stem is not impregnated with the hardening liquid, or when the impregnation amount is small, an adhesive is used when integrally molding a laminate composed of the sheet-like material and the covering material. The adhesive used at that time may be a known adhesive, for example, urea resin, melamine / urea co-condensation resin, phenol / melamine resin, phenol resin, phenol / resorcinol resin, resorcinol resin, epoxy resin, urethane resin, aqueous polymer. Isocyanate adhesives including isocyanate adhesives, tannin resins, liquefied lignocellulose resins, vinyl acetate resins, vinyl acetate / acrylic co-condensation resins, ethylene / vinyl acetate co-condensation resins, α-olefin resins, natural rubber, synthetic rubber, Alternatively, one kind or a mixture of two or more kinds thereof is used. The amount of adhesive used depends on the selected adhesive, but generally one of the adhesive surfaces
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 significantly increased as compared with the performance of the laminated material.

The laminate composed of the sheet-like material and the covering material is, if necessary, temporarily pressed, and then integrally hot-pressed at a temperature of room temperature to 250 ° C. and a pressure of ^{2 to} 30 kg / cm ^2. It shape | molds and manufactures the target laminated material. By disposing spacers in a hot press at the time of molding, the laminated body can be made into a laminated material having a predetermined thickness. In order to increase the surface smoothness of the laminated material, or to obtain a highly accurate thickness,
After molding, the laminated material is surface-treated with a scraper, a planer, a sander or the like, if necessary.

[0013]

In the laminated material of the present invention, a single sheet-like material is integrally coated with a covering material made of a wood material, a metal material, an inorganic material, rubber, a synthetic resin, or the like on one side or both sides. The material provides excellent surface smoothness, workability, and aesthetics, and the sheet-like material improves the mechanical strength and imparts lightness. When the plant stem is impregnated with the hardening liquid, the effect of reducing the amount of the adhesive used at the time of lamination or not using it at all can be obtained. When the sheet material and the covering material are integrally molded using the adhesive, the adhesive is dried, and the hardening liquid is hardened to be changed into a resin compound, thereby forming a reinforced laminated material.

[0014]

As described above, according to the present invention, an inexpensive laminated material can be obtained by effectively utilizing plant stems which are abundant in resources. When a covering material made of a wood material is used, the laminated material exhibits mechanical strength equivalent to that of plywood even when the density thereof is in the range of 0.3 to 0.5 g / cm ³ . Therefore, for example, by using a thin veneer, a low specific gravity particle board or a fiber board, a laminated material having an extremely light weight and excellent mechanical strength can be obtained. When a coating material made of a metal material or an inorganic material is provided on the surface of the laminated material,
Functions such as fireproof, sound insulation, heat insulation, and electromagnetic insulation can be added. The thus obtained laminated material of the present invention is used as a base plate when applying makeup with print paper, vinyl chloride film or the like, or as a base plate when applying makeup with a veneer of natural wood. Further, it can be widely used for various construction materials, interior materials, partition materials, door materials, furniture panels, table materials and the like. Furthermore, by selecting a coating material made of a metal material, an inorganic material, or a synthetic resin, it can be widely used as a heat insulating material, a sound absorbing material, a sound insulating material, a decorative material, or various display materials.

[0015]

Embodiments of the present invention will now be described in detail with reference to the drawings. <Example 1> Sheets of 30 x 30 cm ² were prepared by arranging tall canyon stalks cut to a length of 30 cm in parallel with each other in a circular state without severing them and binding them with threads.
An aqueous polymer isocyanate-based adhesive (KR-134 manufactured by Koyo Sangyo Co., Ltd.) was applied to one surface of the sheet-like material at a rate of 100 g / m ² . 0.9m thick as coating material on this coated surface
After laminating the birch veneer of m so that the fiber direction of this veneer and the fiber direction of the high stalk of the sheet-like material are orthogonal to each other, the laminated body is put in a hot press kept at 140 ° C., Heat press at 4 kg / cm ² for 5 minutes,
A plate-shaped two-layer laminated material having a thickness of 6 mm as shown in FIG. 1 was obtained. In FIG. 1, 20 is a laminated material, 21 is a sheet-like material,
Reference numerals 22 respectively denote the cover single plates integrally joined to the sheet-like material 21. From this laminated material, a test piece was cut out in a shape such that the length direction of the test piece was parallel to the fiber direction of the high stem and the bending strength was measured. As a result, the average bending strength when a load is applied from the sheet side is 422 kg / cm.
^{It was 2} , and the average bending strength when a load was applied from the birch single plate side was 527 kg / cm ² .

Example 2 Phenolic resin (TD-6 manufactured by Oshika Shinko Co., Ltd.) was added to corn stalks cut to a length of 30 cm.
20% of 2) was impregnated and dried. After dividing the impregnated stem into two in the fiber direction, the stems are arranged so that they are parallel to each other, and the ends are temporarily fixed with an adhesive tape to 30 × 30 cm.
A sheet-like material of No. ² was produced. An aqueous polymer isocyanate-based adhesive (Koyo Sangyo KR-1
34) was applied on each side at a rate of 100 g / m ² . After stacking 0.8 mm-thick South Sea wood veneer as a covering material on this coated surface, the three-layer laminate is formed into 15
It was placed in a hot press maintained at 0 ° C. and hot pressed at a pressure of 5 kg / cm ² for 5 minutes to obtain a plate-shaped three-layer laminated material having a thickness of 3 mm as shown in FIG. 2, the same symbols as those in FIG. 1 indicate the same components. From this laminated material, a test piece was cut out in a shape such that the length direction of the test piece was parallel to the fiber direction of the Southern Ocean veneer, and the bending strength was measured. As a result, the average bending strength was 265 kg / cm ² .

[Brief description of drawings]

FIG. 1 is a perspective view of a laminated material having a two-layer structure of the present invention.

FIG. 2 is a perspective view of a laminated material having a three-layer structure of the present invention.

FIG. 3 is a perspective view of a plant stem that is a starting material of a sheet-like material constituting the laminated material of the present invention.

[Explanation of symbols]

 10 Plant Stem 10a Skin Part 10b Pith Part 20 Laminated Material 21 Sheet-like Material 22 Coating Material

Claims (9)

[Claims] 1. A skin portion (10) mainly composed of lignocellulose
A coating material (22) is provided on one side or both sides of a single sheet-like material (21) formed by arranging a plurality of plant stems (10) having a) and a porous pulp part (10b) in parallel with each other. A laminated material integrally formed with the sheet-like material. 2. The plant stem (10) is high-yarn, corn,
The laminated material according to claim 1, which is a stem of a grass family plant containing sugar cane. 3. The plant stem (10) comprises a liquid compound capable of polymerizing, a resin liquid or a hardening liquid of a mixture thereof.
The laminated material described. 4. The laminated material according to claim 1, wherein the covering material (22) is made of wood material, metal material, inorganic material, rubber, synthetic resin, paper, synthetic paper, woven cloth, non-woven cloth, or felt. 5. A skin part (10) mainly composed of lignocellulose
a) and a step of forming a sheet-like article (21) by arranging a plurality of plant stems (10) having a porous pulp portion (10b) in parallel with each other,
One side or both sides of the sheet-like material (21) or a covering material (22)
A method for producing a laminated material, which comprises a step of applying an adhesive on one side, a step of laminating a coating material (22) or a sheet-like material (21) on the adhesive-applied surface, and a step of molding the laminated body. Method. 6. A skin portion (10) mainly composed of lignocellulose
a) and a process of impregnating a plant stem (10) having a porous pulp (10b) with a liquid compound capable of polymerizing, a hardening liquid of a resin liquid or a mixture thereof, and the impregnated plant Stem (1
0) are arranged in parallel to each other to form a sheet-like material (21), a step of laminating a covering material (22) on the sheet-like material (21), and the laminate is molded and cured. A method of manufacturing a laminated material, which comprises a step of curing a liquid. 7. The method for producing a laminated material according to claim 6, wherein the curing liquid is a liquefaction liquid of lignocellulose or a resinification liquid of lignocellulose. 8. The plant stem (10) is compressed to form cracks in the skin before being formed into a sheet-like material (21), or cut and opened in the fiber direction, or divided into a plurality of parts. Or the method for producing a laminated material as described in 6 above. 9. A coating material (22) or a sheet-like material (21) is applied to one surface or both surfaces of a sheet-like material (21) or one surface of a coating material (22), and then the adhesive-coated surface. The method for producing a laminated material according to claim 6, wherein the are laminated.