JP2603882B2 - Composite plate and method of manufacturing the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a composite board used as a building material or a member for furniture, and a method for producing the same.

<Prior art and its problems> Wood boards, which are generally called sawn timber, plywood, and veneer laminates (LVL, LVB), are used in a wide variety of applications as architectural and furniture components. Since it has a fiber direction, it expands and contracts with the absorption and release of water, and particularly has a large expansion rate in a direction perpendicular to the fiber direction and lacks dimensional stability. Further, since there is a conduit hole on the surface, there has been a problem that it is necessary to perform a base treatment such as a sealer treatment and a sealing treatment at the time of processing such as surface painting and paper sticking.

Compared with the above-mentioned wood board, wood fiber board formed by adding and mixing an adhesive to wood fiber has no directionality of wood fiber, expansion and contraction due to absorption and release of moisture are uniform in each direction, and dimensional stability. Is excellent. According to Japanese Industrial Standards, this wood fiber board is roughly classified into three types, a soft fiber board, a medium fiber board, and a hard fiber board, according to the specific gravity. These various fiberboards have different properties and strengths depending on the difference in specific gravity, and are used for different applications. That is, soft fiberboard is mainly used for building ceilings, base materials, tatami floors, etc., medium fiberboard is mainly used for building materials and furniture members, and hard fiberboard is mainly used for exterior materials and automobile interior members. ing.

By the way, there are two types of wood fibers used for manufacturing the wood fiber board: softwood fibers obtained by defibrating softwood materials and hardwood fibers obtained by defibrating hardwood materials. It can be classified into board and hardwood fiber. Softwood fibers are thin and long and white, whereas hardwood fiberboard is obtained from inexpensive hardwood, but the fibers are coarse and the color tone is close to brown. For this reason, the softwood fiberboard has a smooth surface and becomes white, and the subsequent surface decoration treatment, for example, adhesion of paint, veneer, decorative paper, etc. can be performed smoothly. On the other hand, the hardwood fiberboard has fine irregularities due to coarse wood fibers on its surface, and a brownish color tone appears on the surface, so that surface cosmetic treatment is difficult. In addition, the softwood fiberboard has long and thin fibers that are strongly entangled. Therefore, when pressed under the same heat and pressure conditions, a specific gravity higher than that of the hardwood fiberboard, and a material having higher compressive strength and bending strength can be obtained.

<Means for Solving the Problems> In view of the above-described problems of the conventional wood board, the present invention focused on the difference between the softwood fiber board and the hardwood fiber board as described above, and conducted intensive research. It was created as a result.

That is, the present invention relates to a method for producing the wood fiber in the cell pore and / or the cell pore inner wall surface and / or
Alternatively, a composite board is characterized in that a coniferous fiber layer in which a nonflammable inorganic compound is filled or adhered or adhered to the outer periphery of the wood fiber is laminated. The hardwood layer shall be obtained by bonding and molding a material in which a nonflammable inorganic compound is filled, adhered, or fixed to the inside and / or inner wall surface of the wood fiber and / or the outer peripheral portion of the wood fiber. Can be.

In addition, the method for producing a composite board according to the present invention is a method in which softwood material is defibrated on the surface or front and back of a hardwood fiber mat layer formed by adding an adhesive to hardwood fibers, A softwood fiber mat layer formed by adding an adhesive to a wood fiber filled or adhered to or adhered to or adhered to a non-flammable inorganic compound in the pores and / or the inner wall surface of the cell pores and / or the outer periphery of the wood fiber is disposed. After the lamination is performed, it is characterized in that it is press-clamped to be integrally bonded.

The composite board according to the present invention has, for example, the configuration shown in FIG. 1 and has softwood fiber layers 1a, 1
b, and the hardwood fiber layer 2 is arranged between the front and back softwood fiber layers 1a and 1b to be laminated and integrated.

The softwood fiber layers 1a and 1b are made of, for example, softwood materials such as pine, cedar, and hinoki as chips, and then divide the wood fiber obtained by defibrating according to a conventional method into the cell pore and / or the inner wall of the cell pore. /
Alternatively, it is composed of a softwood fiber obtained by incombustible treatment by filling, adhering, or fixing an incombustible inorganic compound to the outer periphery of the wood fiber.

The hardwood fiber layer 2 is made of wood fibers obtained by defibrating hardwood such as rawan, poplar, kapole, chestnut and the like according to a conventional method, and if necessary, incombustible in the same manner as softwood wood fibers. It is composed of modified hardwood fibers.

The method for producing a composite plate of the present invention will be described below with reference to FIG. A softwood fiber mat production line and a hardwood fiber mat production line produce a softwood fiber and a hardwood fiber, respectively, to which an adhesive has been added, and a softwood fiber mat is arranged on the front and back surfaces and between the front and back softwood fiber mats. After laminating so that the hardwood fiber mats are arranged, the composite board of the present invention is manufactured by pressure-tightening and integrally bonding. Hereinafter, each step will be described in detail.

Conifer fiber mat production line For example, one or more kinds of softwood such as pine, cedar, toga, cypress, etc. are used as wood chips, and they are steamed under high-temperature and high-pressure steam and degreased and softened. Then, the fibers are refined by a defibrating device to obtain softwood fibers. Most of the softwood fibers have a length of 1 to 30 mm and a thickness of about 2 to 300 μm. This coniferous fiber has the form of a bundle of several to several tens of cell holes consisting of wood cells and conduit holes,
Since the cell wall around the fiber is often torn or cracked, it absorbs a lot of moisture and moisture.

The obtained softwood fiber is thrown into a drying device and adjusted so that its water content is about 7 to 15%.

The pores of the dried coniferous fibers such as cell pores and conduit holes are filled with a nonflammable inorganic compound, or the nonflammable inorganic compound is fixed or adhered in a layer along the inner wall of the cell pores. The non-combustible inorganic compound is fixed or adhered to the outer peripheral portion to perform the non-combustible treatment. This non-combustibility treatment can be performed, for example, by the following steps.
That is, a softwood fiber is converted to an aqueous solution of a water-soluble inorganic salt (hereinafter referred to as “first
Liquor "). At this time, it is effective to forcibly accelerate the impregnation by applying reduced pressure or increased pressure. Also, the softwood fiber is brought into a high water content state without drying, or once dried, immersed in water or warm water to absorb water and made saturated, and then immersed in the first liquid to diffuse and impregnate. Is also good. As the first liquid, MgCl ₂ , MgBr ₂ , MbSO ₄ .H ₂ O, Mg (NO ₃ ) ₂ .6H ₂ O, AlC
_{l 3, AlBr 3, Al 2} (SO 4) 3, Al (NO 3) 3 · 9H 2 O, CaCl 2, CaB
r ₂ , Ca (NO ₃ ) ₂ , ZnCl ₂ , BaBr ₂ , BaCl ₂ .2H ₂ O, Ba (NO ₃ ) ₂
And the like. By immersing the softwood fiber in the first liquid, the ions of the solute inorganic salt diffuse into the cell pores of the softwood fiber by diffusion.

Next, a dewatering process is performed to remove an excess of the first liquid. The dewatering treatment is performed by means such as centrifugal dewatering or showering, washing with soaked water, and the like. By removing the excess first liquid, the excess non-flammable inorganic compound is generated on the softwood fiber surface. Control and improve the diffusion and impregnation of the aqueous solution to be subsequently impregnated. Further, it is possible to prevent the generation of a nonflammable inorganic compound in a free state that is not attached or fixed to the softwood fiber.

Next, a compound liquid that reacts with the first liquid to generate a water-insoluble incombustible inorganic compound (hereinafter, referred to as “second liquid”)
Is added to softwood fiber using a blender, spray or the like or mixed or immersed, so that the second liquid is impregnated in the softwood fiber. As in the case of the first liquid, the impregnation of the softwood fiber with the second liquid can be promoted by the decompression or pressure treatment. Na ₂ CO ₃ , H ₂ S
O ₄ , (NH ₄ ) ₂ CO ₃ , Na ₂ SO ₄ , (NH ₄ ) ₂ SO ₄ , H ₂ PO ₄ , Na ₂ HPO ₄ ,
(NH ₄ ) ₂ HPO ₄ , H ₃ BO ₃ , NaBO ₂ , NH ₄ BO _{2 and the} like are exemplified. By applying or dipping the second liquid, the second liquid is diffused and impregnated into the cell pores of the softwood fibers, and the first liquid and the second liquid react in the softwood fibers to produce a nonflammable inorganic compound. .
Examples of the generated nonflammable inorganic compounds include calcium compounds such as magnesium phosphate, calcium phosphate, barium phosphate, aluminum phosphate, magnesium borate, magnesium carbonate, calcium carbonate, zinc phosphate, barium carbonate, calcium nitrate, and barium nitrate. , Magnesium compounds, aluminum compounds, barium compounds, lead compounds, zinc compounds, silicate compounds and the like. For example, when barium chloride is used as the first liquid and ammonium hydrogen phosphate is used as the second liquid, barium cation and phosphoric acid anion react to form barium phosphate and barium hydrogen phosphate. Is done.

After the completion of the reaction, the excess second liquid is removed by dewatering by means of centrifugal dewatering or washing with water such as showering or soaking. The immersion treatment and the liquid removal treatment of the second liquid may be repeatedly performed as necessary. After the deliquoring treatment, it is dried to a water content of 25% or less, preferably 7 to 15%.
Since the nonflammable inorganic compound is insoluble in water, it is adhered or fixed after filling to the inside of the cell pore or the inner wall of the cell pore of the softwood fiber and also to the outer periphery of the softwood fiber after drying. As a result, the non-combustible inorganic compound is present in such a manner that pores and cracks appearing on the surface of the softwood fiber are closed or filled.

It is preferable that the non-combustible inorganic compound is mixed at a rate of 33% by weight or more based on the softwood fiber, and if it is less than this, sufficient fire protection performance cannot be obtained. In order to increase the reaction efficiency between the first liquid and the second liquid, the addition and mixing of the second liquid is preferably performed in a heated atmosphere, particularly at a temperature of 40 ° C. or higher, more preferably 50 ° C. or higher. When the first liquid and the second liquid are in a warm water state and the softwood fibers are immersed in the state, or when the first liquid and the second liquid are immersed, electric or mechanical vibration is given by ultrasonic waves or a vibrator. Diffusion and reaction of the treatment liquid into the softwood fibers are performed well. The first
Regardless of the order of processing with the liquid and the second liquid, the processing with the second liquid may be performed first.

Thus, a non-combustible inorganic compound is fixed to the inside of the cell pore or to the inner wall surface, and the non-combustible inorganic compound is fixed or adhered also to the outer peripheral portion thereof to obtain a non-combustible softwood fiber.

Next, this non-combustible softwood fiber is put into a mixing device,
Add adhesive and let it adhere. In the mixing device, optional additives such as a water generating agent and a smoke reducing agent can be simultaneously mixed as needed. Further, when the same type or different types of non-combustible inorganic compounds produced by the reaction of the first liquid and the second liquid are mixed into the adhesive and used, the fire prevention performance can be further improved. As the adhesive, a urea resin adhesive,
Synthetic resin adhesives such as phenolic resin adhesives, melamine resin adhesives, epoxy resin adhesives, isocyanate / vinyl acetate resin adhesives, and modified resins thereof are preferably used.

The non-combustible softwood fiber to which the adhesive is attached is put into a hot air duct, and dried while being transported by air. The blowing speed at this time is about 15 to 20 m / sec, but the specific gravity of wood fiber, feed amount,
It can be adjusted over a wide range depending on the processing capacity of the preceding and following steps. By this hot air conveyance, the moisture content of the softwood fiber is set to about 6 to 15%.

Dried softwood fibers are formed by forming devices 3a and 3b
(Fig. 3).

Hardwood fiber mat production line The place where hardwood materials such as lauan, kapole, poplar, and chestnut are used as raw materials is treated in the same manner as the softwood fiber mat production line described above. The non-combustible treatment with the non-combustible inorganic compound is performed on hardwood fibers as necessary. After drying, the hardwood fibers are conveyed to a forming device 4 (FIG. 3).

Forming-Hot pressing The softwood fibers and hardwood fibers conveyed to the forming devices 3a, 3b, 4 by the respective production lines are piled up on the conveyor 5 as shown in FIG. A three-layer mat 10 composed of 1a and 1b and having a hardwood fiber mat layer 2 at the center. After the three-layer mat 10 is cut into an appropriate size by the cutting machine 6, the mat is sent to the hot press machine 8 by the conveyor 7 and hot-pressed to produce the composite board of the present invention.

Further, the composite board of the present invention produces a softwood fiberboard from softwood fibers that have been made non-combustible in the manner described above, and if necessary, manufactures a hardwood fiberboard from hardwood fibers that have been similarly made non-combustible. Alternatively, the softwood fiberboard and the hardwood fiberboard are laminated via a urea resin-based, phenolic resin-based, or aqueous vinyl urethane-based adhesive so that the softwood fibers are arranged on the front and back surfaces, and then pressed and bonded by hot pressing. It can also be manufactured.

In a composite board obtained by bonding and integrating a softwood fiberboard and a hardwood fiberboard by the above-described method, the specific gravity of the softwood fiberboard and the hardwood fiberboard is adjusted by adjusting the temperature, pressure and time of the heat and pressure in the manufacturing process. It can be arbitrarily selected from 0.4 or less (soft fiberboard), 0.4 to 0.8 (medium fiberboard) and 0.8 or more (hard fiberboard). Therefore, for example, a hard softwood fiberboard having a specific gravity of 0.8 or more is used as the front and back softwood fiber layers 1a and 1b, and a medium hardwood fiberboard having a specific gravity of 0.4 to 0.8 is selected as the middle hardwood fiber layer 2, and these are laminated and integrally formed. When a composite plate is used, when an external force is applied to the surface, the compressive strength of the softwood fiber layer 1a having a high specific gravity on the front side, the tensile strength of the softwood fiber layer 1b on the back side, and the binding force of the softwood fiber layer are combined. Thus, a composite plate having excellent bending Young's modulus (rigidity), light weight and high strength can be obtained. As described above, the composite board according to the present invention has a strength and weight required according to the intended use by freely selecting the specific gravity of the softwood fiber layer and the hardwood fiber layer, and further adjusting the thickness thereof. It can be.

<Effect> A relatively inexpensive hardwood fiber layer is provided as a substrate of the composite board, and a high-strength, smooth-surface, white-colored softwood fiber layer is provided on the front surface or both front and rear surfaces. In the softwood fiber layer, the softwood fibers are preliminarily made non-combustible to improve the fire prevention performance of the composite board.

<Example> Treatment of softwood fiber Radiata pine chips were boiled at 160 ° C and 7 kg / cm ² for 5 minutes to be degreased and softened. The chips were defibrated with a defibrator refiner, and the resulting softwood fibers were dried.

This softwood fiber was immersed in a 30% aqueous barium chloride solution for 10 minutes, subjected to diffusion treatment, and then drained. This was dried with hot air to adjust the water content to 7%. This softwood fiber is put into a blender, and a 40% aqueous solution of ammonium phosphate is added and mixed, and water-insoluble barium phosphate and barium hydrogen phosphate are dissolved in pores such as cell holes of the softwood fiber or on the outer periphery of the softwood fiber. After the incombustible inorganic compound was formed, it was drained, washed with water, and dried with hot air to a water content of 6%. The weight increase rate of the softwood fiber by this nonflammable treatment was 40%.

Put the non-combustible treated softwood fiber into the blender,
In the blender, 4% of a wax sizing agent and 10% of a phenol resin adhesive were added and mixed with respect to the amount of softwood fiber, and then conveyed to a forming device.

Treatment of Hardwood Fiber Rawan chips were degreased and softened by boiling at 160 ° C. and 7 kg / cm ² for 5 minutes. The chips were defibrated by a defibrator type refiner, and the obtained hardwood fibers were dried.

This hardwood fiber is fire-retarded in the same manner as softwood fiber, and then put into a continuous mixer. In the mixer, 4% of a wax sizing agent and 10%
The phenolic resin adhesive was added and mixed, and then conveyed to a forming device.

Mat forming, hot pressing On a screen conveyor, a first softwood fiber forming device, a hardwood fiber forming device, and a second softwood fiber forming device are installed in this order from the downstream side in the conveying direction of the conveyor. The softwood fiber and the hardwood fiber are dropped on the surface, and the softwood fiber /
A continuous three-layer mat was formed which was deposited in the order of hardwood / softwood fibers.

After cutting this mat to its specified width and length,
It is put into a hot press and hot pressed at 200 ° C for 5 minutes. The front and back softwood fiber layers are 5mm each, and the central hardwood fiber layer is 13m.
m, a total thickness of 23 mm, and a 3 ′ × 6 ′ size composite plate was obtained.

The specific gravity of the wood fiber layer in the obtained composite board is 0.7, the specific gravity of the wood chip layer is 0.6, and the specific gravity of the entire composite board is
0.6.

<Effect of the Invention> The composite board according to the present invention has a hardwood fiber layer made of inexpensive hardwood as a substrate, has a smooth, white surface on one or both surfaces thereof, and has excellent compressive strength and bending strength. Since the softwood fiber layer is provided, a light-weight, high-strength composite board having good surface decorativeness can be obtained at low cost. Since the composite plate of the present invention does not have a fixed fiber direction, problems such as expansion and contraction caused by absorption and release of water and moisture in the conventional composite plate can be solved. Further, since the wood fibers in the softwood fiber layer provided on the surface are subjected to non-combustible treatment,
There is no deterioration or carbonization due to heat, and there is no risk of ignition over a long period of time. Therefore, it is widely used as a building material or furniture / building member even in places where fire is used, such as in kitchens. By similarly treating the wood chips in the hardwood fiber layer with non-combustible material, the fire protection performance can be further improved.

As a hardwood fiber layer as a substrate and a hardwood fiber layer on the front surface or front and back surfaces, respectively, a hardwood fiberboard and a softwood fiberboard manufactured in advance are used, and a composite board obtained by laminating and bonding these fibers is used in the manufacturing process. The specific gravity and thickness of the plate can be arbitrarily adjusted, and a composite plate having a weight and strength according to the application can be easily obtained.

Further, a composite board manufactured by a method in which an adhesive is added to each of softwood fiber and hardwood fiber, forming is performed to form a laminated mat, and then hot pressing is performed, the fibers in each of the softwood fiber layer and the hardwood fiber layer are combined. Bonding (entanglement)
In addition, the softwood fiber and the hardwood fiber are bonded together, and the softwood fiber layer and the hardwood fiber layer are manufactured simultaneously as one plate, so that a very large bonding strength of each layer can be obtained. Further, the thickness of the softwood fiber layer and the hardwood fiber layer can be freely adjusted by adjusting the amount of the softwood fiber and the hardwood fiber dropped from the forming machine when forming the mat.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the structure of a composite plate according to the present invention, and FIG.
FIG. 3 is a process diagram showing a method for producing a composite plate according to the present invention, and FIG.
The figure is a side view schematically showing an example of equipment for performing the steps after the forming in FIG. DESCRIPTION OF SYMBOLS 1a, 1b: Softwood fiber layer, 2: Hardwood fiber layer, 3a, 3b, 4
…… Forming equipment, 8… Hot press machine, 10 ……
3-layer mat

Claims (4)

(57) [Claims] A softwood in which a nonflammable inorganic compound is filled, adhered, or fixed to at least the surface of a hardwood fiber layer in the cell pores and / or the inner wall surface of the wood fibers and / or the outer periphery of the wood fibers. A composite plate comprising a plurality of fiber layers laminated. 2. A coniferous fiber layer in which a nonflammable inorganic compound is filled or adhered or adhered or fixed to the inside and / or the inner wall of the cell hole of the wood fiber and / or the outer peripheral portion of the wood fiber. And a hardwood fiber layer disposed between the softwood fiber layers on the front and back. 3. A softwood fiber layer wherein the hardwood fiber layer is filled, adhered, or fixed to a cell hole of wood fiber and / or an inner wall surface of the cell hole and / or an outer peripheral portion of the wood fiber. The composite board according to claim 1, wherein: 4. A hardwood fiber mat layer formed by adding an adhesive to hardwood fibers, obtained by fibrillating a softwood material on the front surface or the back surface thereof, in a cell pore and / or in a cell thereof. A softwood fiber mat layer formed by adding an adhesive to a softwood fiber filled or adhered or adhered to or fixed to the inner wall surface of the hole and / or the outer peripheral portion of the wood fiber is adhered. A method of manufacturing a composite board, comprising: pressing and then integrally bonding.