JPH11226919A - Palm fiber board and method for producing the same - Google Patents

Abstract

(57) [Summary] (with correction) [PROBLEMS] To provide an improved coconut fiber board having both good moisture permeability and high strength, and having little change in water absorption length. SOLUTION: A fiber formed by attaching an amino resin (at least one selected from urea resin, melamine resin, and urea-melamine resin) or a phenol resin to a fiber mat mainly containing arabic palm fiber and compression-molding the same. At least one surface and / or inside of the plate has a moisture content of 0 to 10% (preferably 0 to 5%, more preferably 0 to 1%) and a Young's modulus of 20 to 600 GPa (preferably 30 to 500 G) under standard conditions.
Sheets (glass cloth) made of inorganic fibers (Pa).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiberboard similar to a wood fiberboard, and more particularly to a fiberboard having excellent moisture permeability and strength and having a small change in water absorption length.

[0002]

2. Description of the Related Art In a wooden house, when a fiber-based heat-insulating layer such as glass wool is formed in a wall, a ventilation layer is formed between the outer wall and the heat-insulating layer in order to release water vapor in the room to the outside. Accordingly, a ventilation method in which the water vapor in the room that has passed through the heat insulating layer diffuses from under the eaves to the outside of the room through the ventilation layer is widely used, particularly in cold regions. In that case, a windproof layer that separates the ventilation layer and the heat insulating layer is required. The windproof layer has a function of retaining the heat insulating layer, but needs to have excellent moisture permeability so that water vapor can be smoothly transmitted to the ventilation layer.

[0003] Conventionally, as a material for forming the windproof layer,
For example, a nonwoven fabric made of polyethylene has been used, but if glass wool or the like is used for the heat insulating layer, there is a disadvantage that the nonwoven fabric swells and deforms due to the expansion force of the heat insulating layer and narrows the ventilation layer. This is particularly likely to occur when a large amount of glass wool or the like is packed in a cold region (see Building Construction Standard Specifications / Commentary JASS24 Insulation Work (edited by the Architectural Institute of Japan)). As a windproof layer with a certain strength, a sizing board, which is a kind of air-permeable soft fiber board, is used, but the sizing board itself can withstand the expansion force of the heat insulating layer, but is itself a structural facing material. It does not have enough strength to function as.

[0004] Structural plywood or Oriented Strand Board (OSB), which is a structural surface material, is also used as a windproof layer. However, these boards have almost no moisture permeability, and water vapor in the walls is transferred to a ventilation layer. There is no ability to spread. Under such circumstances, a technique of palm fiberboard having both moisture permeability and strength has been disclosed (WO96 / 32251). Fiberboards made of natural fibers tend to be more susceptible to the effects of water wetting and humidity, but attempts to improve water resistance such as changes in water absorption length have not been made so far. Prior art includes:
There is an attempt to improve water resistance by mixing a wax in a condensate of a binder, but the effect of stabilizing a change in water absorption length by adding a wax is not sufficient.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points.
An object of the present invention is to provide a coconut fiber board that has both good moisture permeability and high strength, and that has a small change in water absorption length. At the same time, the manufacturing method is also proposed.

[0006]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve these problems, and as a result, have found that a sheet-like material made of inorganic fibers or the like having a very small change in water absorption and a high Young's modulus is obtained. By selecting and laminating this on a coconut fiber board, it has been found that a coconut fiber board excellent in strength and moisture permeability and having a small change in water absorption length can be obtained, leading to the present invention. That is, [1] a fiber board obtained by adhering a curable resin to a fiber mat containing coconut fibers as a main component and compression-molding the fiber mat, wherein at least one surface and / or inside of the fiber board has a moisture content of 0 to 0 in a standard state. The present invention relates to a fiber board obtained by laminating sheet-like materials made of fibers having a modulus of 10% and a Young's modulus of 20 to 600 GPa. [2] The fiberboard according to the above [1], wherein the palm fiber is an oil palm fiber. [3] The present invention relates to the fiberboard according to the above [1] or [2], wherein the curable resin is an amino resin. [4] The fiberboard according to the above [3], wherein the amino resin is at least one selected from urea resins, melamine resins, and urea-melamine resins. [5] The fiberboard according to the above [1] or [2], wherein the curable resin is a phenol resin. [6] The fiber of the sheet material has a water content of 0 in a standard state.
The present invention relates to the fiberboard according to any one of the above [1] to [5], wherein the fiberboard has a Young's content of 2 to 30 GPa. [7] The above [1] to wherein the sheet-like material is made of inorganic fibers
The present invention relates to the fiberboard according to any one of [6]. [8] The fiberboard according to the above [7], wherein the sheet is a glass cloth. [9] A fiber mat is formed from coconut fiber, and the moisture content of this fiber mat and the standard state is 0 to 10%, and the Young's modulus is 20 to
The present invention relates to a method for producing a fiberboard, comprising: attaching a curable resin to a sheet made of 600 GPa fiber, laminating a fiber mat to which the curable resin is adhered, and a sheet, and compression molding.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Coco fibers used in the present invention include coco palm, oil palm, sago palm, date palm, sardine, nipa palm, sugar palm, pea palm, palm,
Fibers such as fibrous bark, petiole base fiber and mesocarp fiber collected from palm plants such as jujube and black clog include fibers obtained by defibrating empty palm bunch of oil palm. Also, a mixture of a plurality of types of coconut fibers is included. Here, oil palm fibers are preferred.

If necessary, organic or inorganic fibers may be mixed with the coconut fibers. Organic fibers include natural vegetable fibers and synthetic fibers. Here, the natural vegetable fibers include hemp fibers of hemp disintegrated, bamboo fibers of disintegrated young bamboo, sugarcane fiber, hechima fiber, pineapple fiber, banana fiber, koulyan fiber, fiber obtained from Inawara, wood fiber and the like. There is no particular limitation as long as it is a fiber obtained from a natural plant. As synthetic fibers polyester fibers, aliphatic or aromatic polyamide fibers, aramid fibers,
Examples thereof include fibers such as polyolefin fibers such as acrylic fibers, polyethylene fibers, and polypropylene fibers, vinylidene fibers, polyvinyl chloride fibers, polyurethane fibers, vinylon, rayon, cupra, and acetate. Examples of the inorganic fiber include asbestos, glass fiber, carbon fiber, boron fiber, silicon nitride fiber, silicon carbide fiber, and Tyranno fiber. These may be mixed alone,
Two or more kinds may be mixed simultaneously.

[0009] The mixing ratio of the fiber mixed with the palm fiber is 50wt%
Less than 40 wt%, more preferably less than 30 wt%. Palm fiber is as thick as about 100-600μm in diameter,
When made into a fiber mat, it depends on the fiber packing density, but between fibers, for example, about 100 μm to 5 mm, preferably 200 μm
A gap having a size of about 3 mm is formed. Therefore, the moisture permeability of the fiber mat is extremely good.

When a curable resin is adhered to the fiber mat and compression-molded, the size of the gap and the density of the gap between the fibers of the obtained fiber board are adjusted by adjusting the amount of the resin or the degree of compression at the time of molding. Various changes can be made. Thus, the moisture permeability of the fiberboard can be controlled. For example, the gap of the fiberboard is about 1 to 100 μm, usually 5 to 50 μm.
By setting it to about m, it is possible to produce a good fiberboard that has air permeability and moisture permeability but does not allow rainwater to pass through.

Among palm fibers, oil palm fibers are preferred. This oil palm fiber requires less labor for defibration and the like than other types of palm fiber, and can be obtained at low cost. In addition, oil palm fiber has a fiber length of about 10 ~
Since the length of the fiber is as long as 30 cm and the degree of bending of the fiber is larger than that of the coconut fiber, the fibers are entangled with each other, and are not easily loosened when a fiber mat is formed, and the mat can be easily handled. In addition, the fiber entanglement is large, and the fiber diameter is sometimes larger than that of coconut. The fiber board obtained by using the oil palm fiber is preferable because the nail holding force at the time of nailing is strong.

By laminating a sheet made of fibers having a low hygroscopicity and a high elastic modulus on the palm fiber mat,
Further, not only the strength is improved, but also the change in the water absorption length of the fiberboard can be suppressed. The low hygroscopic fiber has little effect on water absorption, and by selecting a sheet-like material formed of fibers having a high tensile modulus, it is possible to suppress a change in the water absorption length of the board against the water absorption expansion of the coconut fiber.

The fibers constituting the sheet material satisfying the moisture content specified in the present invention have a moisture content in a standard state of 0 to 10%, preferably 0 to 5%, more preferably 0 to 5%.
1% low hygroscopic fiber. What is the standard state here?
It is in a state of equilibrium in an environment of 20 ° C. and 60% RH, and the moisture content is calculated by the formula 1 from the weight W in the standard state and the weight W ⁰ at 105 ° C. at a constant weight.

[0014]

(Equation 1)

The fibers constituting the sheet-like material satisfying the Young's modulus specified in the present invention include fibers having a high tensile modulus and a Young's modulus of 20 to 600 GPa, preferably 30 GPa.
It is a fiber having a high tensile modulus of 500 GPa, more preferably 50 to 300 GPa. Examples of the fibers that can be used as the sheet-like material of the present invention include synthetic fibers such as aromatic polyamide fibers and glass fibers, carbon fibers, inorganic fibers such as boron fibers, steel fibers, and metal fibers such as titanium fibers. Inorganic fibers are preferred, and glass fibers are particularly preferred.

As the sheet-like material, a knitted woven fabric or a non-woven fabric can be used, but as the sheet-like material, a woven fabric having a small elongation to tension is preferable. As an example of the weave structure, it is preferable to select from plain weave, twill weave, satin weave, nanako weave (including regular and irregular), and plain weave and twill weave are particularly preferred. Also, the basis weight is preferably about 100~1200g / m ^2, further 100 to 1000 g /
m ² is preferred, most preferably from 100 to 600 / m ^2.

The amount of the sheet material to be laminated on the palm fiber mat can be selected in combination with the basis weight and the number of laminations depending on the physical properties such as the strength required by the part using the fiber board. The surface of the board may be one side or both sides, and both sides of the board are preferred. The curable resin used in the present invention includes a thermosetting resin and a reaction curable resin (room temperature curable resin). At the time of compression molding, heating is also performed if necessary.

First, as the thermosetting resin, phenol resin, amino resin, and diallyl phthalate resin (DAP)
Resin). Phenolic resins include novolak resins (acid catalyst, excess phenol), resole resins (basic catalyst, excess formaldehyde), phenol-melamine copolymer resin, phenol-melamine-urea copolymer resin, alkylphenol-modified phenolic resin, rubber-modified phenolic resin There are denatured phenol resins such as resins, and amino resins include urea resins (urea resins), melamine resins, urea-melamine copolymer resins, benzoguanamine resins, and acetoguanamine resins. Next, examples of the reaction curable resin (room temperature curable resin) include a furan resin, an alkyd resin, an unsaturated polyester resin, a urethane resin, an epoxy resin, a modified (modified) silicone resin, and a silicone resin.

Further, as the sizing agent or binder for the fiber mat, these curable resins are preferable from the viewpoint of dimensional accuracy, durability, strength and the like. However, although it is slightly inferior in physical properties, it is possible to partially use thermoplastic resins such as acrylic resins and styrene resins (particularly aqueous dispersions) having a binder effect and natural or synthetic rubber latex such as SBR. The curable resin of the invention is a concept including these. Among the above curable resins, a thermosetting resin is preferable from the viewpoint of curing time and productivity, and among them, a phenol resin and an amino resin are preferable, and an amino resin, that is, a urea resin, a melamine resin, and a urea melamine are particularly preferable. Polymer resins and mixed resins thereof are preferred.

The curable resin of the present invention may contain, if necessary, a water-resistance imparting agent such as a wax or a size material, a plasticizer, a filler,
A reinforcing material, an anti-sagging agent, a coloring agent, an anti-aging agent, an adhesion promoter, a curing catalyst, a physical property modifier and the like can be added. In addition, konjac, flour, starch, etc. can be added as an adhesion promoter. The amount of the curable resin used is 5 to 1 part by weight based on 100 parts by weight of raw fibers including coconut fibers and sheet-like fibers.
00 parts by weight, preferably 5 to 30 parts by weight. More preferably, 10 to 30 parts by weight is exemplified.

The fiber mat of the present invention containing palm fibers as a main component is obtained by developing fibers in a mat shape, and tangling the fibers into a non-woven fabric or a three-dimensional knitted structure by needle punch or the like to pull the mat. Includes those that have been treated to improve strength and peel strength. In addition, those in which a binder is adhered to these mats to partially fix the fibers to each other so that the mat fibers are not unraveled are also included. Further, if necessary, the fiber mat is densified by pressing or hot pressing. It should be noted that the thickness of the fiber mat is generally considered to be easy to use when the thickness is about 5 to 20 mm. However, it is needless to say that the fiber mat is not limited to this and may be set arbitrarily according to the application. Is also good.

An example of the embodiment of the present invention will be described. The fiber board of the present invention forms a fiber mat with fibers mainly composed of coconut fibers, for example, a glass cloth is laminated as a sheet on both surfaces of the fiber mat, a curable resin is adhered to these, and compression is performed. It is formed by molding. To form a fiber mat, after expanding palm fibers into a mat,
In order to increase the peel strength and tensile strength of the fiber mat, it is preferable to carry out a process of entanglement of the coconut fibers into a nonwoven fabric or a three-dimensional knitted structure by needle punching or the like.

The thickness of the fiberboard of the present invention is preferably 3 to 25 mm, more preferably 9 to 20 mm. This fiberboard has high strength, and by adjusting the density of the fiberboard and the amount of curable resin, for example, the bending strength and the wet bending strength can be reduced from 5 types to 30 types.
It can be equal to or higher than the type of medium fiberboard. On the other hand, it is also possible to obtain a value whose moisture permeability is equal to or higher than that of the seasing board.

The flexural strength of fiber board is preferably 3~50N / mm ^2, more preferably ^{5~40N / mm 2, 10~40N / mm} 2 being most preferred. If it is less than 3 N / mm ² , the strength of the structural material is insufficient, and if it is more than 50 N / mm ² , it is generally necessary to increase the fiberboard density, which causes a decrease in moisture permeability, making it possible to achieve both strength and moisture permeability. It tends to be difficult. 0.1-10μg moisture permeability coefficient
/ (mm ² · s · Pa) is preferable, 0.5 to 8 µg / (mm ² · s · Pa) is more preferable, and 1 to 7 µg / (mm ² · s · Pa) is most preferable. 0.1
[mu] g / is less than (mm ² · s · Pa) is insufficient as a windbreak layer that transmits water vapor to vent layers in walls, generally fiberboard To ^{10μg / (mm 2 · s ·} Pa) or more It is necessary to reduce the density, and the strength is reduced, and it is difficult to achieve both strength and moisture permeability.

Furthermore density fiberboard is preferably 0.2~1g / cm ^3, preferably further 0.3 to 0.7 g / cm ^3, most preferably from 0.35~0.6g / cm ^3. The method for producing the fiberboard of the present invention can be performed, for example, as follows. First, coconut fiber is defibrated, the unit cross-sectional diameter is about 5-600 μm, and the fiber length is 30-30.
Obtain 0 mm fiber. A mat-like thing is formed by this palm fiber. If necessary, such a fiber mat is entangled with a fiber by a needle punch or the like to be dense, and at the same time, the peel strength is increased. An aqueous solution or dispersion of a curable resin is sprayed on the fiber mat by spraying or the like, so that the resin is uniformly attached to the entire fiber mat. Next, a resin liquid is applied to the glass cloth by spraying, laminated on both sides of the fiber mat, and subjected to heat compression molding. Depending on the density and thickness of the desired fiberboard, a plurality of fiber mats may be appropriately laminated.

The temperature and time of the heat compression vary depending on the used cured resin, the water content of the fiber mat before the heat compression, and the like, and may be appropriately adjusted according to the respective conditions. In addition, the resin is used as a sizing agent or binder for the fiber mat, and also provides a strength to the glass cloth itself as a sheet-like material and a binder between the glass cloth and the fiber mat, and furthermore, a binder or Works as a component for imparting strength.

The glass cloth, which is the most preferable example of the sheet-like material, is knitted with a fiber having a high tensile strength and a high tensile elasticity, and therefore exhibits excellent tensile strength and a high tensile elasticity. The glass cloth is strongly bonded to the fiber mat via the resin, so that the strength of the fiberboard is increased. That is, when the glass cloth is disposed on both sides of the fiber mat, a so-called sandwich effect is exhibited, and the bending strength and the bending elastic modulus of the fiber board are increased.
Further, since the glass cloth has no dimensional change at the time of water absorption and moisture absorption, it is preferable to arrange the glass cloth on both sides of the fiber mat, since the dimensional change at the time of water absorption and moisture absorption of the fiberboard and the decrease in strength at the time of water absorption and moisture absorption are small. Therefore, the fiberboard functions as a structural face material, and can reinforce the structural portion around the windbreak layer.

In the above description, the glass cloth is disposed on both surfaces of the fiber mat. However, the present invention provides a method in which the glass cloth is disposed only on one surface of the fiber mat, a method in which the glass cloth is disposed inside the fiber mat, and a method in which the glass cloth is disposed. Surface or one surface as well as those located inside. Further, in the case where the glass cloth is arranged inside the fiber mat, a case where a plurality of hemp cloths and a plurality of palm fiber mats are alternately stacked and arranged in a multilayer shape is included. When glass cloth is placed inside the fiber mat, the tensile strength and tensile modulus, shear strength and shear modulus, and in-plane compressive strength and in-plane compressive modulus of the fiberboard increase, and the fiberboard It functions as a surface material and can reinforce the structure around the windbreak layer.

When the glass cloth is disposed on the surface, the coconut fiber mat and the glass cloth may be compression-molded after lamination as described above, or may be adhered to the fiberboard surface with an adhesive or the like after the coconut fiberboard is formed. Is also good. Further, in the above embodiments, only the fiberboard having a rectangular shape in a front view and a constant thickness has been described.However, it may be a molded body formed into a desired shape by various shapes of molds at the time of compression hardening molding. The same operation and effect as those of the fiberboard can be obtained.

[0030]

Next, the present invention will be described in detail with reference to examples and comparative examples. The change in water absorption length of the obtained fiberboard is JIS A 5905
Was evaluated. Using Example 1 fibrillating the oil palm fibers, the fibers are entangled by needle punching to prepare a fiber mat having a basis weight of 1.7 kg / m ^2. Urea resin (Euroid U-755 manufactured by Mitsui Toatsu Chemicals, resin solid content 65 wt%) and NH ⁴ as a curing catalyst
Cl (1 part by weight with respect to 100 parts by weight of resin solid content) was mixed and diluted with water. The resin solution prepared above was mixed with the above-mentioned oil palm mat and a glass cloth having a basis weight of 0.2 kg / m ² (WETO manufactured by Nitto Boseki).
A7628-125) (Glass fiber standard moisture content 0.0%, Young's modulus 74-77GPa) Spray-coated by spray method, and adhere 20 parts by weight of urea resin as resin solids to 100 parts by weight of fiber Was. Two oil palm fiber mats with resin adhered, one glass cloth laminated on each side, and heat compression molding at 165 ° C for 8 minutes with a press machine,
A fiberboard having a thickness of 9.0 mm and a density of 0.5 g / cm ³ was obtained.

Table 1 shows the evaluation results of the change in the water absorption length of the obtained fiberboard. [Comparative Example 1] Instead of a glass cloth, a jute cloth (having a basis weight of 0.3 kg / m ² ) (the standard state moisture content of the jute fiber is 13)
%, Young's modulus of 8 to 15 GPa), and a fiberboard having jute cloth laminated on the surface was obtained in the same manner as in Example 1. The obtained fiberboard was evaluated in the same manner as in Example 1, and the evaluation results are shown in Table 1. [Comparative Example 2] A fiber board made of only palm fibers was obtained in the same manner as in Example 1 without laminating the sheet-like materials. The obtained fiberboard was evaluated in the same manner as in Example 1, and the evaluation results are shown in Table 1.

[0032]

[Table 1]

Table 1 shows that the change in the water absorption length was smaller in the example in which the glass cloth was laminated than in Comparative Example 1 in which the jute cloth was laminated, and the change in the water absorption length was able to be suppressed by the present invention as compared with the conventional example. did it. Therefore, it can be seen that the material is a suitable building material with little dimensional change after construction under wet or humid environment.

[0034]

As described above, a fiberboard obtained by adhering a curable resin to a palm fiber mat and compression-molding the same.
By laminating sheets made of fibers having a low moisture content in the standard state and a high Young's modulus, a fiberboard with excellent strength and moisture permeability, and a smaller change in water absorption length than conventional coconut fiberboard, and a method for producing the same are proposed. Could be provided.

Since the fiberboard of the present invention is excellent in strength and moisture permeability and has good length stability, if a windproof layer is formed from these fiberboards, indoor water vapor can be smoothly transmitted through the ventilation layer. In addition to being able to hold the heat insulation layer stably, the dimensional change after construction is small even under wet or humid environment, and good dimensional stability even when using long materials It is very preferable as a building material because it can secure the same.

The fiberboard of the present invention may be used as a windproof layer used for forming a ventilation layer on the outer wall of a house as described above, but is not limited thereto. For example, home interior materials, interior base materials, roof base materials, ceiling materials, floor materials, floor base materials, tatami floors, structural structural heat insulating materials, sound absorbing materials, sound insulating materials,
Plywood, glulam, building materials such as shock absorbers, cushioning materials, and rims
It can be used for all building material applications where particle boards are used. Furthermore, it can also be used as a material for concrete forms, pallets, packaging materials, vehicle interior materials such as automobiles, interior base materials, exterior materials, furniture materials and the like.

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Claims (9)

[Claims] 1. A fiberboard obtained by adhering a curable resin to a fiber mat containing palm fibers as a main component and compression molding, wherein at least one surface and / or inside of the fiberboard has a water content of 0 to 0 in a standard state. A fiberboard made by laminating sheet-like materials consisting of fibers with 10% and a Young's modulus of 20 to 600 GPa. 2. The palm fiber according to claim 1, wherein the palm fiber is oil palm fiber.
The fiberboard as described. 3. The fiberboard according to claim 1, wherein the curable resin is an amino resin. 4. An amino resin comprising a urea resin, a melamine resin,
The fiberboard according to claim 3, wherein the fiberboard is at least one selected from urea-melamine resins. 5. The fiberboard according to claim 1, wherein the curable resin is a phenol resin. 6. The fiberboard according to claim 1, wherein the fibers of the sheet-like material have a moisture content of 0 to 2% and a Young's modulus of 30 to 500 GPa in a standard state. 7. The sheet according to claim 1, wherein the sheet is made of inorganic fibers.
7. The fiberboard according to any one of 6. 8. The sheet-like material is a glass cloth.
The fiberboard as described. 9. A fiber mat is formed from coconut fiber, and a curable resin is adhered to the fiber mat and a sheet made of fibers having a water content of 0 to 10% and a Young's modulus of 20 to 600 GPa in a standard state. A method for producing a fiberboard, comprising laminating a fiber mat with a conductive resin and a sheet-like material, and compression molding.