JP3363641B2 - High-strength composite board and method of manufacturing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-strength composite board used for civil engineering and construction and general industry, and a method for producing the same, and more particularly to a wood board high-strength composite board requiring strength and a method for producing the same.

[0002]

2. Description of the Related Art Wood boards mainly include so-called composition boards such as plywood, particle boards and fiber boards, all of which are widely used. The plywood is made by thinly peeling thick South Sea wood etc. with veneer lace and laminating multiple boards alternately so that the fiber directions are almost orthogonal to each other with an adhesive, or by kneading sawdust etc. with an adhesive to form a plate. The thin plate material is attached to both the front and back surfaces of the product. These plywoods are used in large quantities for panels for concrete pouring work and other construction civil engineering. However, in order to produce these, it requires a considerable amount of huge trees, but even in the tropics, it takes a long time for trees to grow into such mature trees, and if they are cut down carelessly, the forests can be regenerated. There is a problem that is impossible. In order to reduce the global warming and desertification tendency that has become a problem in recent years, it is necessary to reduce the consumption of timber and protect forests carefully. Therefore, plates made of aluminum or thermoplastic resin have been proposed, but all of them are heavy and difficult to process at the construction site, and when they become industrial waste, they are recycled. It is difficult to use and there is a problem to dispose of it.

On the other hand, composition boards other than plywood are mainly composed of, for example, particle board, fiber board, wood cement board, wood chips, paper pulp, fiber,
There are boards that mix crushed materials of various wastes. The particle board is made into chips by shredding wood, woodworking scraps, waste wood, defective wood, and the like into chips, and adding a synthetic resin binder to the mixture, followed by heat compression molding. The fiberboard is made by mixing a plant fiber with a synthetic resin binder and subjecting it to heat compression molding. Since the wood fibers are uniformly dispersed, the strength and the expansion / shrinkage ratio have no directionality, and there is an excellent feature that cracks or deformation do not occur during use. The wood cement board is made by treating wood wool, wood chips, chips, etc. with calcium chloride solution, mixing it with cement, and compression-molding it into thick plates or hollow blocks.
It is also characterized by excellent sound insulation, heat insulation, and fire protection.

As described above, the raw materials for these composition boards are those which have conventionally been incinerated or discarded as wastes such as wood, wood chips, waste materials and defective plate materials.
These are finely crushed and used as fibers or flakes. Further, as these raw materials, crushed materials such as various kinds of factory waste and household waste are also used. In this way, the composition board is a product that makes effective use of the natural resource of wood, and it is expected that it will be used more and more widely in the future because it effectively uses various kinds of waste and revives it as a useful product. Is expected.

However, since the above-mentioned composition board generally does not have the strength as plywood, it can be widely used as a furniture, a structural material of a building, etc., but a concrete panel or the like requiring a particularly high strength. There is a problem that it is not suitable for the application. Furthermore, particleboard has insufficient peeling resistance between particles, so when using it for furniture, it is necessary to use one with a specific gravity of 0.65 or more to maintain the strength of the kumite used for joining members. Therefore, there is a certain limit to cost reduction and weight reduction.

Further, since the composition board generally has a weak holding force for wood screws, nails, tapping screws, etc., special screws or metal fittings are required instead of them.
Further, the composition board is not suitable for use around water because it is greatly expanded and deformed by moisture absorption or water absorption and has a large strength reduction rate. Also, in order to produce a wood board, usually a urea melamine copolymer resin binder is used,
It has been pointed out that there is a problem in hygiene because its component, formalin, remains in the product and is gradually released into the air over a long period of time.

As one method for solving these problems, a method of attaching a reinforcing material impregnated with a thermosetting resin to a glass fiber mat or a glass woven cloth has been proposed. However, in such a reinforcing material, since the resin used is a thermosetting resin, the impregnation state of the resin deteriorates when the fiber content is increased to increase the strength, and it is also difficult to reduce the thickness. There is a certain limit to strength and weight reduction, and it is necessary to press and bond the reinforcing material at high temperature for a long time to bond the reinforcing material to the wooden board, resulting in poor productivity and the wooden board due to heat and pressure. There is a problem of deterioration. Furthermore, as long as a thermosetting resin is used, it shrinks when it hardens, so it is difficult to prevent the warpage that occurs with it.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and its purpose is to mainly use wood boards that can save valuable forest resources and absorb water. The expansion coefficient is prevented from lowering due to, and the holding power for wood screws, etc. is improved, and it is lighter than the conventional particle board alone, and has excellent mechanical properties such as strength, rigidity and durability, so a small amount of raw materials can be used. The desired strength is obtained, the release of formalin is small, and it is safe for health,
It is to provide a high-quality high-strength composite plate and a method for manufacturing the same.

[0009]

The first object of the present invention is to align continuous filaments in one direction on one surface on one surface or both surfaces of the wood board as described above. Align, and the fiber content is 40% or more by weight.
High strength obtained by heat-bonding a reinforcing plate that is impregnated with a thermoplastic resin to 80% or less and is molded into a sheet, either alone or by laminating multiple prepregs with their fiber orientation changed. Achieved by a composite board. Thus, as wood boards, in addition to particle boards, fiber boards, plywood, wood cement boards, etc., mainly wood chips and wood fibers are mixed with crushed materials of various wastes and binders, and these are kneaded. A board formed by pressing, molding or the like is used.

In a preferred embodiment, the base wood board has a depth of 0.
A thermoplastic resin of the same type as that impregnated into the reinforcing plate is impregnated over a length of 1 to 1 mm to form a heat-sealing layer, and the reinforcing plate is heat-bonded thereto. In addition, it is recommended to mix short fibers in the heat-sealing layer. In another preferred embodiment, the prepregs constituting the reinforcing plate are laminated in a plurality of layers, preferably two or more layers and four or less layers with the fiber directions changed. Further, the reinforcing plate preferably has a coefficient of thermal expansion in the fiber direction of 10 ⁻⁵ / ° C. or less. A thermoplastic resin plate of the same type as that used for the reinforcing plate may be laminated on the surface or the inner layer of the reinforcing plate. In addition, it is recommended that the wooden board is covered not only with its surface but also with its end portion with a reinforcing plate. In still another embodiment, for example, an embossed sheet-like skin material or decorating material is adhered to the surface, and a protective resin film is further adhered thereon.

A second object of the present invention is (a) a step of producing a desired wood board by a conventional method, and (b) at least one layer of continuous filaments aligned in one direction on one plane. Align, and the fiber content is 40% or more by weight.
A step of producing a reinforcing plate using a prepreg obtained by impregnating a thermoplastic resin into a sheet shape so as to be 80% or less, and (c) a melting temperature of the thermoplastic resin impregnated with the reinforcing plate. This is achieved by a method for producing a high-strength composite board, which comprises the steps of heating the thermoplastic resin in a molten state and superposing it on a wooden board, pressurizing, press-bonding, and cooling and solidifying.

Then, on the surface of the wooden board to which the reinforcing plate is adhered, the thermoplastic resin of the same kind as that impregnated into the reinforcing plate in its molten state is penetrated to a depth of 0.1 to 1 mm. Then, it is desirable that the heat-sealing layer is formed and the reinforcing plate is heat-bonded thereto. In a further preferred embodiment, in the process of manufacturing the reinforcing plate, a plurality of layers of prepreg are laminated, and the orientation direction of the fiber is changed in each layer. In yet another embodiment, for example, an embossed sheet-like skin material and various decorative materials are adhered to the surface thereof, and a protective resin film is temporarily attached thereon. Can be worn. The resin constituting the reinforcing plate is preferably a polyolefin-based resin or a polystyrene-based resin, and various known fibers can be adopted as the continuous long fibers to be mixed with the reinforcing plate.
Especially glass fiber and carbon fiber are recommended.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of a high-strength composite plate according to the present invention, FIG. 2 is a perspective view showing a state in which the high-strength composite plate shown in FIG. 1 is bent, and FIG.
Is a perspective view showing an embodiment different from the above, FIG. 4 is a cross-sectional view showing the structure of a high-strength composite plate having a skin material on the surface, and FIG. 5 is the same type as that used for the reinforcing plate on the surface layer of the wood board. 6 is a partially enlarged cross-sectional view showing a state in which a thermoplastic resin is soaked to form a heat fusion layer, and FIG. 6 is a partially enlarged view showing a state in which short fibers are mixed in the heat fusion layer shown in FIG. Sectional view, FIG. 7 is an explanatory view showing an outline of an apparatus for producing a high-strength composite plate according to the present invention, and FIG. 8 is an explanatory view showing an outline of an apparatus used for a strength test of the high-strength composite plate according to the present invention. is there. In these figures, in order to show the cross-sectional structure in detail, the thickness is emphasized in comparison with the surface dimension.

In FIG. 1, 1A is a flat plate-shaped high-strength composite board suitably used for concrete formwork, etc.
Reinforcing plates 12 and 13 are heat-bonded to both front and back surfaces of, and integrated. Reference numeral 15 is a heat-sealing layer formed by exuding and permeating the surface of the wooden board 11 with the thermoplastic resin used to form the reinforcing plates 12 and 13. Reinforcement plates 12, 13
Is a prepreg, that is, continuous long fibers are aligned and aligned in one direction, and the blending ratio of the fibers is 40% or more by weight.
%, Or less, preferably 2 to 4 sheets, which are impregnated with a thermoplastic resin, are laminated by changing the direction of the fibers. Wood board 11 and reinforcing plates 12, 13
To attach, heat the reinforcing plates 12 and 13 above the melting temperature of the thermoplastic resin impregnated into them, and lay them on the wooden board 11 in the molten state, and press 3 kg by pressing.
It is cooled and bonded under a pressure of not more than / cm ² .

At this time, the melted thermoplastic resin penetrates into the voids between the wood particles on the surface of the wood board 11 and wraps them in the heat fusion layer 15
Is formed, and when the resin is cooled and solidified, this heat fusion layer
The wooden board 11 and the reinforcing plates 12 and 13 are firmly joined to each other through the interposition 15. The details of the heat sealing layer 15 are shown in FIG.
Is shown in. In the figure, 11-1 is a large particle forming the core of the wooden board 11, and 11-2 is a small particle existing in the surface layer. Reinforcement plate
12 is a prepreg laminated by changing the direction of its fibers by 90 degrees
It consists of 12-1 and 12-2. Reference numeral 16 is a thermoplastic resin that has exuded from the reinforcing plate 12 to the wooden board 11.

As described above, the thermoplastic resin 16 fills the space between the fibers mixed in the reinforcing plate 12 and also fills the space between the particles constituting the wood board 11,
Since both are integrated, a wooden board 11 and a reinforcing plate 1
2 and 13 are firmly joined. The heat-sealing layer 15
The thickness is preferably 0.1 mm or more and 1 mm or less. When the heat-sealing layer 15 is not sufficiently formed or the thickness thereof is less than 0.1 mm, the adhesive strength is remarkably reduced and the reinforcing effect is lost. On the other hand, it is difficult to form the heat fusion layer 15 having a thickness of more than 1 mm, and the adhesive strength does not increase even if the thickness is increased. Further, in the state shown in FIG. 6, a large number of short fibers 17 are mixed on the surface of the wooden board 11, and since these short fibers 17 are entangled with the glass fibers forming the reinforcing plate 12, a stronger adhesive force can be obtained. It is a thing.

The wood board 11 is heated to a temperature at which the resin can flow so that the thermoplastic resin flows and efficiently fills the voids inside the wood board 11 to obtain the heat-sealing layer 15 having a sufficient thickness. It is desirable to preheat. Further, on the surface of the reinforcing plate 12, if a resin film made of a thermoplastic resin of the same kind as the thermoplastic resin used for the reinforcing plate 12 is previously fused, the resin of the resin film is melted at the time of joining, and wood Since it penetrates well into the surface of board 11,
The thickness and resin content of the heat-sealing layer 15 increase, and reliable adhesion is ensured. In this way, by forming the heat-sealing layer on the surface of the wooden board 11, the surface of the wooden board 11 and the reinforcing plate 12 can be firmly joined without using an adhesive or the like, and the wooden portion The exposed area of is reduced, and the effect of reducing the amount of formalin released is also obtained.

FIG. 2 shows a curved plate 1B having an arc-shaped cross section as an embodiment of the high-strength composite plate according to the present invention. This is one in which reinforcing plates 12 and 13 are attached to a bent wooden board 11 and is suitable for a curved concrete panel or the like. If the wood board 11 and the reinforcing plates 12 and 13 have the same vertical and horizontal dimensions, there arises a problem that the reinforcing plates 12 and 13 are easily peeled off from the corners.
In order to prevent this, it is recommended to use a reinforcing plate 12 whose vertical and horizontal dimensions are slightly smaller than that of the wooden board 11, as shown in FIG. In the high-strength composite board 1C configured in this way, the reinforcing plate 12 does not come off from the corners of the wooden board 11 and is easy to handle.

Furthermore, in order to prevent the reinforcing plate 12 from peeling from the end of the wooden board 11, a reinforcing plate 12 having a size larger than that of the wooden board 11 is used.
The wooden board 11 may be wrapped by bending the end portion of the. In this way, the end of the wooden board 11 will be wrapped by the reinforcing plate 12, the overall strength of the composite board and the local strength of the corners will be increased, and peeling of the reinforcing plate 12 will be prevented. Is.

In the composite board 10 shown in FIG. 4, reinforcing plates 12 and 13 are attached to both front and back surfaces of a wooden board 11, and a thin sheet-like skin material 14 is attached to the surface of the reinforcing plate 12 on the front side. It consists of In the case of concrete formwork, the skin material 14 improves the releasability from the concrete and smoothes the surface of the cast concrete,
There are cases in which a smooth surface is used to achieve glossiness, and cases in which various patterns are transferred to the outer surface of the structure and subjected to embossing or the like for the purpose of enhancing its aesthetic appearance. In the latter case, depending on the skin material 14, the wood grain,
It is possible to transfer various patterns such as stone texture, brush eyes, and line drawing to the concrete placing surface.

In the case of a high-strength composite plate used for interior walls, partitions, etc., wood-grain printing paper, wood-based thin plate, etc. are used as the skin material 14. For outdoor use, a resin film or metal foil with excellent weather resistance is used. A thin layer of thermoplastic resin is formed on the surface of the reinforcing plate, and since the thermoplastic resin has poor surface activity, an adhesive is applied to this surface to try to adhere the surface material for decoration. In that case, the effect of the adhesive may not be sufficiently exhibited, and the desired adhesive strength may not be obtained. In such a case, in order to obtain sufficient adhesive strength, it is necessary to subject the surface of the reinforcing plate to sanding, corona discharge treatment, chemical etching, etc., but these treatments cost a considerable amount. There is.

In order to solve this problem, it is recommended to attach a porous sheet of thick paper, non-woven fabric or the like to the reinforcing plate in advance. Since the adhesive penetrates well into the porous sheet pasted here, when this is used, when the decorative skin material is bonded to the reinforcing plate, part of the thermoplastic resin that constitutes the reinforcing plate is porous. Since it exudes into the quality sheet and forms the same heat-sealing layer as described above, it is possible to firmly bond the reinforcing plate and the decorating material. Even in this case, in order to prevent the skin material 14 from peeling from the end portion, it is recommended to wrap the end portion of the wood board 11 with the skin material 14.

Materials constituting each part will be described below. There is no particular limitation on the thermoplastic resin constituting the reinforcing plate, for example, polystyrene, polyvinyl chloride, linear low density polyethylene, low density polyethylene, high density polyethylene, polypropylene, polycarbonate, polybutylene terephthalate, polyethylene terephthalate, Polyethersulfone, polysulfone, polyetherimide (trademark: ULTEM), polyetheretherketone, polyphenylene sulfide, etc. can be used, but strength, abrasion resistance, price and ease of recycling when discarded From this point of view, general-purpose polyolefin resins such as polyethylene and polypropylene and polystyrene resins are recommended as the most desirable resins.

The continuous long fibers to be mixed in the reinforcing plate include synthetic resin fibers such as aramid fibers (registered trademark "Kepler"), natural organic fibers, metal fibers such as titanium, boron and stainless steel, glass and carbon. , And inorganic fibers such as silicon carbide. However, the material is not necessarily limited to these, and any material that has sufficient strength and is inexpensive and available in large quantities may be used. The blending ratio of the continuous filaments is 40 to 80% by weight, preferably 45 to 70%. When the compounding ratio is less than 40%,
Since the flowability of the resin increases at high temperatures, it becomes difficult to shape the reinforcing plate, and it becomes difficult to obtain the rigidity and abrasion resistance required for the plate, and when the compounding ratio exceeds 80%, the adhesiveness decreases. In addition, the molding process becomes difficult. Further, it is recommended that the continuous long fibers in the reinforcing plate be aligned and aligned in a certain direction, usually a direction in which bending stress is received during use, before use. It is also recommended to use this blended fiber as a composite laminate of a layer oriented in such a direction as to receive bending stress during use and a layer oriented in a direction perpendicular thereto.

The prepreg which constitutes the reinforcing plate can be manufactured by the method disclosed in Japanese Patent Publication No. 2-42168. That is, a monofilament of a reinforcing glass fiber is treated with a coupling agent, for example, γ-methacryloxy-propyltrimethoxysilane, and a large number of bundled yarns are aligned while being drawn while uniformly tensioned and applied. It is obtained by contacting a thermoplastic resin and impregnating the resin while squeezing with a hot roll.

It is recommended to use two or more layers of this prepreg, but when a reinforcing plate is attached to only one side of a wooden board, the composite plate warps when the reinforcing plate is too thick. Can be seen. Therefore, the thickness of the prepreg single layer is set to 50 μm or more and 600 μm or less, and it is desirable to keep the thickness to 1 mm or less even when the prepreg single layer is used by laminating two or more and four or less layers. Further, even if the thermal expansion coefficient of the reinforcing plate is large, the composite plate warps, so the thermal expansion coefficient is preferably 10 ^-5 / ° C or less. As the material constituting the skin material, a foamed or non-foamed sheet such as polypropylene or polystyrene, PV
Examples include thermoplastic resin products such as C and PZT sheets, metal foils, paper, and woven and non-woven fabrics made of various fibers. When a resin is used as the material of the skin material, it is desirable to use the same type of resin as the resin used for the reinforcing plate.

The adhesion between the wooden board and the reinforcing plate will be described below. Generally, a reinforcing plate composed of continuous long fibers and a thermoplastic resin is heated to a temperature above the melting temperature of the thermoplastic resin, laminated on both front and back surfaces of a wooden board, and then pressed and shaped by a press roller or the like. A desired skin material is attached to the surface of the laminate as needed to obtain a laminate.
As a method to secure the reinforcing plate and the wooden board by heat welding, heat the wooden board together with the reinforcing plate to the melting temperature of the resin that constitutes the reinforcing plate, and then stack the reinforcing plate and the wooden board at room temperature to 80
0.1 kg / cm ^{2 in a} press machine heated to about ℃
Above, it is recommended to pressurize at a pressure of 3 kg / cm ² or less and then cool. Further, at this time, it is necessary to remove the air existing between the prepreg layers constituting the reinforcing plate, but normally the air is naturally degassed when the bonding is performed under the above conditions. Moreover, if the pressure is within the above range, the wooden board will not be crushed. As a matter of course, there is no problem in using a reinforcing plate that has been degassed and cooled in advance.

The reinforcing plate and the wooden board may be heated individually without contacting each other, or may be heated simultaneously with the reinforcing plate placed on the wooden board and in contact with each other. At this time, in order to obtain a strong joining force,
As described above with reference to FIG. 6, it is recommended to mix short fibers in the surface layer of the wooden board, but a thermoplastic resin layer containing short fibers is provided between the wooden board and the reinforcing plate. It is also effective to form them and connect them with short fibers at the time of joining.

The length of the short fibers used here is 0.1 mm or more and 100 mm or less. If the length is less than 0.1 mm, the connection becomes impossible, but if the length is more than 100 mm, the connecting force does not increase. The preferred length of short fibers is 0.5 m
It is m or more and 20 mm or less. Examples of the short fibers include fiber bundles such as polyolefin resin fibers, polyester resin fibers and glass fibers, and non-woven fabrics. The thermoplastic resin layer containing these fibers is configured to uniformly cover the surface of the wooden board. Alternatively, the surface of the wooden board may be covered with a chop material made of a thermoplastic resin containing glass fiber, for example.

The thermoplastic resin heated above the melting temperature is generally in a meltable and flowable state, but the weight ratio is 40%.
In the composite material containing the above fibers, since the resin is held in a state in which the resin cannot freely flow in the lattice of fibers, even if pressure for shaping is applied in that state and the fiber structure is deformed,
Since the overall shape of the fiber is a stable structure,
A high-quality and high-precision molded product can be obtained without the resin leaking to the outside.

Since the reinforcement plate and the wooden board must be integrated while the thermoplastic resin of the reinforcement plate is in a molten state, a device that can shift from the heating step to the cooling integration step in a short time. is necessary. FIG. 7 shows an example of such a high strength composite board manufacturing apparatus. This apparatus comprises a hot press 20 for preheating a wooden board, a hot press 30 for preheating a reinforcing plate, and a joining press 40 for cooling and bonding. Wooden board manufactured by a press (not shown) for manufacturing wooden board
Reference numeral 11 indicates that at least the surface temperature of the reinforcing plate 12 is heated to an appropriate temperature close to the melting temperature of the thermoplastic resin used for the reinforcing plates 12 and 13 by the hot press 20 for preheating the wood board, and a reinforcing plate (not shown) is also used. The reinforcing plates 12 and 13 manufactured by the press for manufacturing are hot pressed 30 while being sandwiched between the release sheets 22 for protection,
It is heated above the melting temperature of the thermoplastic resin used for its production.

The reinforcing plate 12 has the release sheet 22 on its upper surface removed by a device (not shown), and is placed on the die of the joining press 40 by a transfer device (not shown). Then, a wooden board 11 is similarly overlaid thereon by a transport device (not shown), and the reinforcing plate 13 is joined and pressed by another transport device (not shown).
The release sheet 22 on the lower surface
Are removed and stacked on the wooden board 11. Then, the punch of the joining press descends and presses the reinforcing plates 12 and 13 and the wooden board 11 sandwiched therebetween,
The die and punch of this joining press are provided with a circulation channel 41 for the cooling liquid, and the temperature of the die and punch is always maintained at a temperature significantly lower than the melting temperature of the thermoplastic resin, so the reinforcing plate 12 , 13 and the wooden board 11 sandwiched between them are cooled, and the thermoplastic resin therein is solidified, so that a high-strength composite board is completed.

The results of a comparative test conducted to examine the characteristics of the high-strength composite plate according to the present invention will be described below. In the comparative tests described below, various combinations of the wood board and the reinforcing plate used were used to prepare test samples of Example 35 and Comparative Example 14 as shown below, and their physical properties and Comparative measurements such as mechanical strength were performed. The test procedure is as follows.

The prepregs used in this example were all manufactured by the method disclosed in Japanese Patent Publication No. 2-42168. In the case of glass fiber, the surface of a monofilament with a thickness of 13μ is treated with γ-methacryloxy-propyltrimethoxysilane, and 1800 filaments are bundled into a twist-free yarn, and the yarn is pulled in one direction while pulling it with uniform tension. The prepreg was manufactured by aligning and entwining the resin with the yarn and impregnating the yarn with the resin while ironing the resin with a hot roll.

In the case of carbon fiber, without using a sizing agent, the 12000 tows collected from the monofilaments having a thickness of 7 μ are aligned in one direction while pulling with a uniform tension, and the resin is entangled with the yarn, Was squeezed with a hot roll to impregnate the yarn to produce a prepreg. The prepreg manufactured in this manner has excellent adhesion between the fiber and the thermoplastic resin, the fiber content can be changed to 40 to 80% by weight as required, and the thickness should be 0.01 to 1.0 mm. You can These prepregs can be used in a single layer or two layers,
The fiber direction was changed by 90 degrees and laminated to form a reinforcing plate.

Table 1 shows the constitution of prepregs manufactured for use in the examples of the present invention and comparative examples. The prepregs A to E in the table are those having a fiber compounding ratio of 40% or more and 80% or less, that is, those according to the present invention, and the same F and G are outside the above range, that is, tested as a comparative example. It is a thing.

[Table 1]

In the test, particle boards, fiber boards and plywood were used as wood boards. Table 2 shows the properties of the wooden boards used.

[Table 2]

Each wooden board was cut into a square of 500 mm square. Cut out two square prepregs each with a length of 500 mm and a width of 500 mm as a set, and
Two prepregs were stacked one on top of the other so that the fiber directions of the prepregs were orthogonal to each other and bonded to form a reinforcing plate. The apparatus shown in FIG. 7 was used for manufacturing the high-strength composite plate. Die and punch the hot press 20 to 100 ° C, and the hot press 30 it to 2
It was heated to 00 ° C. and that of the bonding press 30 to 70 ° C. respectively. Pressurization of the hot press 20 is 3kg / cm ²
It was 2 minutes. In the hot press 30, the reinforcing plate was sandwiched between the release films 22 and preheated for 2 minutes while applying a pressure of 0.1 kg / cm ² . The pressure of the bonding press 40 is
It was 1 kg / cm ² for 1 minute.

The structures and materials of the test samples used were as shown in the following table. In addition, all the examples were manufactured in the same manner as the example 1 except for the following matters and those shown in this table. The + sign in the prepreg column indicates that a two-layer prepreg in which the orientation directions of the fibers differ by 90 degrees was used, and the-sign indicates that the prepreg is a single layer. In Examples 9, 21 and 33 (marked with a star in the remarks column), when joining materials by a joining press, the release sheet of one reinforcing plate was peeled off, and a 0.2 m thick polyethylene terephthalate non-woven fabric was used as the skin. After bonding as a material and joining, apply adhesive to the surface of the non-woven fabric, thickness 0.2 mm
It is a walnut thin plate glued together. Example 1
In Nos. 0, 22 and 34 (marked with a star in the remarks column), when joining the materials by the joining press, the unstretched polypropylene resin film having a thickness of 100 μm was sandwiched between the front and back surfaces of the wooden board and the reinforcing plate and joined. In Example 11 (marked with ▽ in the remarks column), when joining materials by a joining press, a 0.5 mm-thick non-woven fabric made of glass fiber having a thickness of 17 μm was sandwiched between the front and back surfaces of the wooden board and the reinforcing plate. Joined. In Example 23 (marked with Δ in the remarks column), when joining materials by a joining press, a 0.2 mm thick nonwoven fabric made of polyethylene terephthalate was sandwiched between the front and back surfaces of the wooden board and the reinforcing plate and joined.

[0040]

[Table 3]

The test samples shown in the following table were prepared for comparison with the above examples. Of the following comparative example samples, those with a reinforcing plate attached to make a composite plate,
Manufactured under the same conditions as in Examples 1, 12 and 24 above, except that the fiber loading of the reinforcing plate was different. These comparative samples have the same dimensions as the above-mentioned working samples,
That is, it was cut into a size of 500 mm square and tested in the same manner as in the example.

[Table 4]

The contents of the tests carried out are as follows. Bending property test: JIS A5908 Measurement of bending strength and bending elastic modulus. Breaking load test: Only carried out on examples using plywood. Water absorption test: JIS A5908 After being immersed in water for 24 hours, the water absorption rate, the moisture absorption dimension change rate, and the moisture absorption thickness change rate are measured. Wood screw holding power: JIS A5908 Performed in Examples 1 to 11 and Comparative Examples 1 to 4. Formalin test: Comparison between Examples 1, 12 and 24 and the wood boards used for them. Peeling test: Inspect whether peeling occurs at the joint surface between the wooden board and the reinforcing plate.

The results of the test of the composite board using the particle board as the wood board are as shown in Table 5. In the column of the peeling test, ⊚ indicates that the heat-welding layer did not peel, and damage occurred inside the wooden board, and x indicates that the heat-welding layer peeled.

[Table 5]

From this table, when particle board is used as the wood board, the high-strength composite board according to the present invention has flexural strength 3 to 4 times that of particle board and flexural modulus.
When it is reinforced by 1.5 to 2 times, and when reinforcing plates are provided on both sides, the water absorption rate is reduced to 1/3 to 1/5, the moisture absorption dimension expansion rate is halved, and the thickness expansion rate is about 1 It was found that the value was / 6 or less, and that the wood screw holding power was also improved about twice. Also, when the fiber content of the reinforcing plate is 40% or less (Comparative Example 1), the increase in strength is not remarkable, and conversely, when it is 80% or more (Comparative Example 2), the result of the peel test may be poor. known. It should be noted that the strength is particularly improved in Example 4 in which carbon fiber is used for the reinforcing plate and Example 11 in which the glass nonwoven fabric is provided between the wooden board and the reinforcing plate.

The test using the fiberboard as the wood board was carried out in the same manner as the above-mentioned particle board test except that the wood screw holding power test was not carried out.
The result of the test of the composite board using this fiberboard is
It is shown in Table 6 on the next page. From this table, it is known that when the medium fiber fiber board was used, the same results as when the particle board described above was used were obtained.
That is, the high-strength composite board according to the present invention is reinforced to have a flexural strength of 3 to 4 times and a flexural modulus of 1.5 to 2 times that of the fiberboard. It is found that the dimensional expansion coefficient is reduced to 1/3 to 1/5, the hygroscopic dimensional expansion coefficient is halved, and the thickness expansion coefficient is about 1/6 or less. It should be said that also in Example 18 using the soft fiber fiber board, extremely favorable results were obtained when compared with the characteristics of the board (Comparative Example 9). In addition, when the fiber content of the reinforcing plate is 40% or less (Comparative Example 5), the increase in strength is not remarkable, and conversely, when it is 80% or more (Comparative Example 6), the result of the peel test may be poor. This is the same as when using a particle board. Also in this test, it was known that the strength was particularly improved in Example 15 in which carbon fiber was used for the reinforcing plate.

[Table 6]

For the wood board using lauan plywood, a breaking load test was conducted instead of the wood screw holding power test. This breaking load test was carried out by an apparatus as shown in FIG. In FIG. 8, 50 is a 500 mm square sample board to be tested, 51 is an indenter for applying a load, and 52 and 52 are 400 mm for supporting the sample board 50.
The support device is composed of a pair of fixed cylinders that are fixed in parallel with each other. The sample board 50 is placed on the supporting devices 52, 52 and receives the load of the indenter 51 at the center thereof. The load of the indenter 51 is increased until a crack is generated on the surface, and its limit load is measured. The results of tests of composite boards using this lauan plywood are shown in Table 7 below.

[Table 7]

When plywood is used, since the bending strength and the flexural modulus of plywood are originally high, the improvement ratios thereof are not as high as those of the examples using the particle board and fiber board, but the breaking load strength is 3 to. It is markedly strengthened by 5 times. Further, when the fiber mixture ratio of the reinforcing plate is 40% or less (Comparative Example 10), the increase in strength is not expected, and
If it exceeds 80% (Comparative Example 11), the result of the peeling test becomes defective, so that improvement in bending strength cannot be observed. Example 27 using carbon fiber for the reinforcing plate
In particular, the breaking load strength and the bending strength are remarkably improved.

The following Table 8 shows the results of measurement and comparison of the residual amounts of formalin of the high-strength composite boards of Examples 1, 12 and 24 and the wood boards used for them. From this table, it is known that the residual formalin is almost halved compared to the wood board of the material.

[Table 8]

[0049]

The high-quality and high-strength wooden board according to the present invention is lighter than conventional ones, easy to handle on site, requires a small amount of raw materials, and has high compressive strength. In addition, it has a prepreg laminate made of fiber-reinforced synthetic resin with extremely high rigidity and tensile strength on both front and back sides.Therefore, if this is used, the overall rigidity is extremely high, and a very solid structure can be used during use. Can be built. Further, according to the method of the present invention, it is possible to inexpensively supply a large amount of high-quality and high-strength wooden boards that have high strength, are excellent in water resistance and corrosion resistance, and have little dimensional change due to moisture absorption.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a high-strength composite plate according to the present invention.

FIG. 2 is a perspective view showing a state where the high-strength composite plate shown in FIG. 1 is formed into a curved surface.

FIG. 3 is a perspective view showing an embodiment different from that shown in FIG.

FIG. 4 is a cross-sectional view showing the structure of a high-strength composite plate having a skin material on its surface.

FIG. 5 is a partially enlarged cross-sectional view showing a state in which a heat-sealing layer is formed on the surface layer of the wooden board.

FIG. 6 is a partially enlarged cross-sectional view showing a state in which short fibers are mixed in the heat fusion layer.

FIG. 7 is an explanatory view showing the outline of an apparatus for producing a high-strength composite plate according to the present invention.

FIG. 8 is an explanatory diagram showing an outline of an apparatus used for a breaking load test of a high-strength composite plate according to the present invention.

[Explanation of symbols]

1A-High-strength wooden board 1B ・ ・ ・ ・ ・ High-strength wooden board 1C: High-strength wooden board 10 ・ ・ ・ ・ ・ High-strength wooden board with skin material 11 ・ ・ ・ ・ ・ Wood board 12 ・ ・ ・ ・ ・ Reinforcement plate 13 ・ ・ ・ ・ ・ Reinforcement plate 14 ・ ・ ・ ・ ・ Surface material 15 ... Heat fusion layer 16: Thermoplastic resin 17 ・ ・ ・ ・ ・ Short fiber 20 ・ ・ ・ ・ ・ Hot press for preheating wood boards 22-Release film 30 ・ ・ ・ ・ ・ Hot press for preheating the reinforcing plate 40-Joining press 41 ・ ・ ・ ・ ・ Refrigerant introduction line 50 ・ ・ ・ ・ ・ Test piece 51 ・ ・ ・ ・ ・ Indenter 52 ・ ・ ・ ・ ・ Supporting device

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroaki Tomimoto 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Co., Ltd. (72) Hiroshi Tabe, 1190 Kasama-cho, Sakae-ku, Yokohama, Kanagawa Mitsui Toatsu Chemical Co., Ltd. (72) Inventor Yoshiharu Miyasaka 1190, Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Co., Ltd. (56) Reference JP-A-1-163062 (JP, A) JP Flat 2-160511 (JP, A) JP 63-74606 (JP, A) JP 58-31716 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B32B 1 / 00-35/00 B29B 11/16 B29B 15/08-15/14 C08J 5/04-5/10 C08J 5/24

Claims (9)

(57) [Claims] 1. A prepreg obtained by impregnating continuous continuous fibers for reinforcement, which are aligned in one direction while being pulled by a uniform tension, with a molten thermoplastic resin and impregnated with the resin. Reinforcing plate (12, 13) made of prepreg having a content of 40% or more and 80% or less and a coefficient of thermal expansion in the fiber direction of 10 ^-5 / ° C or less
On a wooden board (11) on one side of the wooden board or
Reinforcement plate at depth of 0.1 to 1 mm from both sides
A high-strength composite plate (1A, 1B) impregnated with the thermoplastic resin of 1 to form a heat-sealing layer and heat-bonded. 2. The high-strength composite plate (1) according to claim 1 , wherein the heat-sealing layer is a layer containing short fibers.
A, 1B). 3. The wood board (11) is a particle board, fiber board, plywood or a wood raw material layer mainly containing wood chips and fibers coated with a binder.
Alternatively, the high-strength composite plate (1A, 1B) described in 2 . 4. A prepreg alone or with a mating angle of 0 to 90.
The high-strength composite plate (1A, 1B) according to claim 1, wherein a reinforcing plate (12, 13) formed by laminating a plurality of sheets at an arbitrary angle of ° is used. 5. The high-strength composite plate (1A, 1B) according to claim 4 , wherein the reinforcing plate (12, 13) is a laminate of 2 to 4 prepregs. 6. The high-claim according to claim 1, characterized in that a skin material is laminated and integrated on the surface of the reinforcing plate (12, 13) on the front side of the wooden board (11) through an adhesive layer. Strength composite plate (1A, 1B). 7. The high-strength composite plate (1A, 1B) according to claim 1, wherein an end portion of the composite plate (1A, 1B) is covered with a skin material. 8. The high-strength composite plate (1A, 1B) according to claim 1, wherein a resin film is laminated on one side or both sides of the reinforcing plate (12, 13). 9. A prepreg obtained by contacting a continuous thermoplastic continuous filament with a molten thermoplastic resin and impregnating the continuous thermoplastic continuous filament with a molten thermoplastic resin, the continuous continuous filament being weighed. Reinforcing plate (12, 13) made of prepreg having a content of 40% or more and 80% or less and a coefficient of thermal expansion in the fiber direction of 10 ^-5 / ° C or less
Is heated to a temperature above the melting temperature of the thermoplastic resin, and the thermoplastic resin is in a molten state, and is overlaid on one side or both front and back sides of the preheated wood board, and then 0.1 kg / cm ² or more by a press or a roller. 3 kg / cm ² or less
A method for producing a high-strength composite plate, which comprises pressurizing with pressure, cooling, solidification, integration, and shaping.