JP6155484B2 - Fiberboard - Google Patents

Description

 The present invention relates to a fiber board containing one kind of bagasse fiber of lignocellulosic fiber, which is cellulose fiber containing lignin, such as wood fiber and wood powder.

A fiberboard containing lignocellulosic fibers such as bagasse fibers and an adhesive (hereinafter sometimes referred to as “lignocellulose fiberboard”) is a member for building materials such as flooring materials, wall materials, and roofing materials. It is used as a material for furniture and furniture (for example, see Patent Document 1).
Such a lignocellulose fiber board is used, for example, around water in a kitchen or the like. When a lignocellulose fiber board is used around water, an antifungal agent is added to impart antifungal properties.

JP2013-151111A

 Lignocellulose fiber boards are produced by molding a kneaded body containing lignocellulose fibers and an adhesive at high temperature and high pressure, so that the kneaded body receives a greater amount of heat than usual during molding, so an antifungal agent is effective. There was a problem that the components were thermally decomposed and the molded lignocellulose fiber board could not exhibit sufficient fungicidal performance.

 The present invention has been made in view of such a problem, and even if it receives a larger amount of heat than usual, it is possible to suppress thermal decomposition of the active ingredient of the antifungal agent, and a fiber excellent in antifungal properties. The purpose is to provide a board.

Fiberboard of the invention, and bagasse fibers, adhesives, Ri heat resistance temperature of the active ingredient the name contains a 180 ° C. or more fungicide, the content of the antifungal agent, dry fiberboard weight and wherein 1.0 × ¹⁰ -6 to 5 wt% der Rukoto in dry weight ratio.

 According to the fiberboard of the present invention, since the heat resistance temperature of the active ingredient contains an antifungal agent having a temperature of 180 ° C. or higher, the active ingredient of the antifungal agent is thermally decomposed by the heat at the time of producing the fiberboard. Therefore, a fiberboard having excellent antifungal properties can be obtained.

An embodiment of the fiberboard of the present invention will be described.
Note that this embodiment is specifically described in order to better understand the gist of the invention, and does not limit the present invention unless otherwise specified.

 The fiberboard of this embodiment contains bagasse fiber, an adhesive, and a fungicide having a heat resistance temperature of 180 ° C. or higher for the active ingredient.

Bagasse fiber is an elongated fiber that remains after squeezing sugar liquid from sugarcane. In this embodiment, it is preferable to use the bagasse fiber after pulverization or defibration to a predetermined size (length, width).
Bagasse fiber consists of squeezed culm after squeezing sugar solution from sugarcane, but contains 0.001 to 20% by weight of sugar per fiber weight.
The average density of the bagasse fibers is 0.68 to 0.95 g / cm ³ , and preferably 0.70 to 0.85 g / cm ³ .
The reason why the average density of the bagasse fibers is preferably within the above range is that when the average density is less than 0.68 g / cm ³ , the entanglement force between the fibers does not occur when the fiberboard is formed. This is because it is impossible to obtain a sufficient holding force. On the other hand, if the average density exceeds 0.95 g / cm ³ , voids inside the fiberboard are almost eliminated, and the fiberboard expands greatly during water absorption.
That is, if the average density of the bagasse fibers is within the above range, a sufficient holding force of the wood screws can be obtained for the fiberboard, and the amount of expansion of the fiberboard during water absorption can be reduced.

The bagasse fibers preferably have a particle size of 40% or more remaining in a mesh of 500 μm or more. The condition of the sieve is 5 g of raw material, stroke 70, and time 2 minutes.
The reason why the particle size of the bagasse fiber is preferably within the above range is that when the fiber particle size of the bagasse fiber is less than 40 μm and less than 40%, the entanglement force between the fibers is not generated when the fiberboard is formed. This is because sufficient wood screw holding force cannot be obtained. That is, if the bagasse fiber particle size is within the above range, sufficient wood screw holding force can be obtained for the fiberboard.

In the bagasse fiber, the ratio of the length to the width of the fiber (hereinafter sometimes referred to as “dimension ratio”) is preferably 10 to 1000, and more preferably 20 to 500.
The reason why the ratio of the length to the width of the bagasse fiber (dimension ratio) is preferably within the above range is that when the fiber sheet is formed when the dimension ratio is less than 10, no entanglement force between the fibers is generated. This is because sufficient holding force of wood screws cannot be obtained. On the other hand, when the dimensional ratio exceeds 1000, when the bagasse fiber and an additive such as an adhesive are kneaded, the fibers are entangled and the additive is not sufficiently dispersed, so that the mechanical strength of the fiberboard decreases. Because it does.
That is, if the dimensional ratio of the bagasse fibers is within the above range, a sufficient holding force of wood screws can be obtained for the fiberboard, and a sufficient mechanical strength can be obtained for the fiberboard.

Examples of the adhesive include various thermosetting resins such as urea resin, melamine resin, urea melamine resin, phenol resin, resorcinol resin, epoxy resin, urethane resin, fuller resin, isocyanate resin, and the like. Is used.
Among these adhesives, those satisfying the highest standard F ☆☆☆☆ (F Forster) are preferable.

The content of the adhesive is preferably 2 to 30% by weight, and more preferably 5 to 20% by weight, based on the dry weight ratio with respect to the dry fiberboard weight.
The reason why the content of the adhesive is preferably within the above range is that when the content of the adhesive is less than 2% by weight, the bonding point between the bagasse fiber and the adhesive is small, so that the adhesive strength between the fibers is increased. This is because a sufficient holding force of the wood screw cannot be obtained. On the other hand, when the content of the adhesive exceeds 30% by weight, the fiberboard becomes too hard and it becomes difficult to insert a nail or a wood screw into the fiberboard.
That is, if the content of the adhesive is within the above range, a sufficient holding force of wood screws can be obtained on the fiberboard, and nails and wood screws can be easily inserted into the fiberboard.

 Here, the dry weight ratio of the adhesive to the dry fiberboard weight is the solid content of the adhesive after drying in 100% by weight when the dry weight of the entire fiberboard of this embodiment is 100% by weight. It is the ratio.

As the antifungal agent having an heat resistance temperature of 180 ° C. or higher for the active ingredient, those having an active ingredient such as an organic iodine compound or a benzothiazole compound are used.
Examples of the organic iodo compound include diiodomethyl-p-tolylsulfone.
Examples of the benzothiazole compound include 2- (thiocyanomethylthioben) benzothiazole.
As will be described later, the temperature at which a kneaded body containing bagasse fiber, an adhesive and a fungicide is heated and pressurized to produce a fiberboard is 170 to 230 ° C., so that the heat resistance temperature of the active ingredient is 180. By using the antifungal agent having a temperature of not lower than ° C. (especially, preferably 180 to 500 ° C.), it is possible to suppress the thermal decomposition of the active ingredient of the antifungal agent due to the heat when producing the fiberboard.
In addition, the active ingredient of an antifungal agent is a component (compound) which shows an antifungal action.

 Here, the heat-resistant temperature of the active ingredient is a temperature at which the active ingredient is thermally decomposed (thermal decomposition temperature), and this thermal decomposition temperature is measured by, for example, differential scanning calorimetry (DSC). be able to.

The content of the fungicide is preferably 1.0 × 10 ^{−6 to} 5 wt% in terms of the dry weight ratio with respect to the dry fiberboard weight, and 1.0 × 10 ^{−3 to} 1.0 × 10 ⁻¹ wt. % Is more preferable.
The reason why the fungicide content is preferably within the above range is that when the fungicide content is less than 1.0 × 10 ⁻⁶ wt%, the fiberboard is provided with sufficient fungicidal properties. It is because it is not possible. On the other hand, when the content of the fungicide exceeds 5% by weight, the curing of the adhesive is inhibited.
That is, when the content of the fungicide is within the above range, sufficient antifungal properties can be obtained for the fiberboard, and the adhesive is sufficiently cured to obtain sufficient mechanical strength for the fiberboard. .

 Here, the dry weight ratio of the fungicide to the dry fiberboard weight is the ratio of the dry weight of the fungicide to 100% by weight when the dry weight of the fiberboard of the present embodiment is 100% by weight. That is.

Moreover, it is preferable that content of a fungicide is 1.0 * 10 < ^-6 > -8 weight% in the dry weight ratio with respect to a dry fiber weight, and 1.0 * 10 < ^-3 > -1.0 * 10 < ^-1 >. More preferably, it is% by weight.
The reason why the fungicide content is preferably within the above range is that when the fungicide content is less than 1.0 × 10 ⁻⁶ wt%, the fiberboard is provided with sufficient fungicidal properties. It is because it is not possible. On the other hand, when the content of the fungicide exceeds 8% by weight, curing of the adhesive is inhibited.
That is, when the content of the fungicide is within the above range, sufficient antifungal properties can be obtained for the fiberboard, and the adhesive is sufficiently cured to obtain sufficient mechanical strength for the fiberboard. .

 Here, the dry weight ratio of the fungicide to the dry fiber weight means that the dry weight of the fungicide in 100% by weight when the dry weight of the bagasse fiber in the fiberboard of the present embodiment is 100% by weight. It is the ratio.

The fiberboard of the present embodiment has a water repellent, a curing agent, a mold release agent, a preservative, an ant proof, in addition to the adhesive and the fungicide, as long as it does not impair the fungicide and mechanical strength. Additives such as agents may be included.
Further, the fiberboard of the present embodiment may include not only bagasse fibers but also fibers such as medium density fiberboard (MDF) and wood chips.

 The method for producing the fiberboard of the present embodiment is not particularly limited. For example, a step of kneading bagasse fibers, an adhesive, and an antifungal agent to produce a kneaded body, and heating and pressurizing the kneaded body. And a method having a process.

In the step of preparing the kneaded body, as a method of kneading the bagasse fiber, the adhesive, and the fungicide, an aqueous solution or dispersion of the adhesive and the fungicide is stirred while spraying the bagasse fiber, and these The method of kneading these materials is used.
Examples of the method for kneading the bagasse fiber, the adhesive, and the fungicide include a method using a blender, a mixer, a mixer, a stirrer, a kneader, and the like.

When kneading the adhesive and fungicide and the bagasse fiber, the moisture content of the bagasse fiber is preferably 30% by weight or less, and more preferably 2 to 15% by weight.
The reason why the moisture content of the bagasse fiber is preferably within the above range is that when the moisture content of the bagasse fiber exceeds 30% by weight, the moisture content of the fiberboard obtained by heating and pressing the kneaded body increases, This is because the mechanical strength of the plate is lowered.

 When an additive is added to the fiberboard of this embodiment in addition to the adhesive and the antifungal agent, the additive is added in the same manner as the adhesive and the antifungal agent in the step of producing the kneaded body.

 Next, the kneaded body is deposited to a predetermined thickness, and then preliminarily pressed to form a pre-formed mat-like material (forming mat).

Next, the forming mat is sandwiched with a hot press plate and heated and pressed to obtain a fiberboard.
In the present embodiment, the molding pressure is increased over a predetermined time at the initial stage of heating and pressurization, and then the steady molding pressure is obtained.
When the molding pressure in the initial stage of heating and pressurization is P ₁ and the steady molding pressure is P ₂ , it is preferable that P ₁ > P ₂ and P ₁ -P ₂ is 7 to 90 MPa.

Although the temperature which heats a forming mat is suitably adjusted according to the kind of adhesive agent which comprises a forming mat (kneaded body), it is preferable that it is 170-230 degreeC, for example, and it is 180-220 degreeC. More preferably, it is 190-220 degreeC.
The temperature at which the forming mat is heated may be constant throughout the process of heating and pressurizing the forming mat, or may be changed within the above range.

The pressure at the time of pressurizing the forming mat is appropriately adjusted according to the composition and size (volume, area) and the like of the forming mat. For example, P ₂ is 3 to 10 MPa, and P _{1 to} P ₂ is 7 to 90 MPa. It is preferable that
In addition, the pressure at the time of pressurizing the forming mat may be constant throughout the process of heating and pressurizing the forming mat, or may be changed within the above range.

 The initial heating and pressing time of the forming mat is appropriately adjusted according to the composition and size (volume, area) of the forming mat, and is preferably 5 seconds to 100 seconds, for example.

 The fiberboard obtained as described above is then cut into a predetermined size as necessary and subjected to a finishing process such as a sanding process to obtain a fiberboard product.

 According to the fiberboard of this embodiment, since the heat resistant temperature of the active ingredient contains an antifungal agent having a heat resistant temperature of 180 ° C. or higher, the active ingredient of the antifungal agent is thermally decomposed by the heat when producing the fiberboard. Since this can be suppressed, a fiberboard having excellent antifungal properties can be obtained. Moreover, since it can suppress that the active ingredient of a fungicide is thermally decomposed, a fiberboard exhibiting sufficient fungicidal performance can be obtained even when bagasse fiber having a high sugar content as a fungi nutrient is used.

 EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited to a following example.

[Example]
The bagasse fiber (70% of what was sieved with a mesh of 500 μm or more) was dried at 200 ° C. so that the water content was 5%.
As an adhesive, a dispersion obtained by dispersing urea melamine-based resin in water (solid content concentration: 60% by weight) so that the amount of adhesive added to the dry fiberboard weight is 10% by weight in terms of solid content. And added with an air spray gun.
Further, as a fungicide, a dispersion (solid content concentration 10% by weight) in which an organic iodide compound having a heat resistance of 200 ° C. or higher as an active ingredient is dispersed in water is used. Was added by an air spray gun so that the dry weight ratio was 1.5 × 10 ⁻² wt%.
Furthermore, 2.5 parts by weight of a dispersion (solid content concentration 20% by weight) in which an ammonium chloride-based curing agent was dispersed in water was added as a curing agent with respect to 100 parts by weight of the adhesive.
Thereafter, the bagasse fiber, the adhesive, the fungicide and the curing agent are kneaded, and the adhesive, the fungicide and the curing agent are uniformly dispersed throughout the bagasse fiber, and the bagasse fiber, the adhesive, the fungicide and the curing agent are dispersed. A kneaded body was obtained.
Next, the kneaded body was supplied to the forming step and spread to form a forming mat, and then the forming mat was temporarily pressed in the preliminary pressing step.
Next, the temporarily mated forming mat (300 mm × 300 mm × 80 mm) was heated and pressurized with a hot press disk from both the upper and lower surfaces to obtain a fiberboard of the example.
In the step of heating and pressurizing the fiberboard, the temperature for heating the forming mat was 180 ° C., the pressure for pressing the forming mat was 1.5 MPa, and the time for heating and pressing the forming mat was 250 seconds.

"Evaluation of mold resistance"
The obtained fiberboard was subjected to a mold resistance test in accordance with Japanese Industrial Standards: JIS Z2911 “Funge Resistance Test Method”.
Table 1 shows the active ingredients of the antifungal agent, the heat resistant temperature of the antifungal agent, and the added amount (content) of the antifungal agent in the examples.
Table 2 shows the area of mold (mold growth area) in the entire surface area of the fiberboard after 1 week, 2 weeks, 3 weeks and 4 weeks after the start of the mold resistance test.

[Comparative example]
As an antifungal agent, one containing an isothiazoline compound having a heat resistance of about 100 ° C. as an active ingredient is used so that the dry weight ratio of the antifungal agent to the dry fiberboard weight is 1.5 × 10 ⁻² wt%. Except having done, it carried out similarly to the Example, and obtained the fiber board of the comparative example.
About the obtained fiber board, it carried out similarly to the Example, and implemented the mold resistance test.
Table 1 shows the active ingredients of the antifungal agent, the heat resistant temperature of the antifungal agent, and the added amount (content) of the antifungal agent in the comparative examples.
Table 2 shows the area of mold (mold growth area) in the entire surface area of the fiberboard after 1 week, 2 weeks, 3 weeks and 4 weeks after the start of the mold resistance test.

 From the results shown in Table 2, it was confirmed that a fiberboard having excellent antifungal properties can be obtained if the active ingredient contains an antifungal agent having a heat resistant temperature of 200 ° C. or higher.

Claims (1)

And bagasse fibers, adhesives, Ri heat resistance temperature of the active ingredient the name contains a 180 ° C. or more fungicide,
The anti content of the antifungal agents are, fiberboard, wherein 1.0 × 10 -6 ^{to 5} wt% der Rukoto a dry weight ratio to dry fiber board weight.