JP2718167B2 - Dry manufacturing method of fiberboard - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a fiberboard by a dry method, and more particularly to a method for producing a fiberboard having excellent strength.

<Conventional technology> Conventionally, a fiber board is prepared by adding and mixing a powdery novolak resin or a resole resin to a fiber, depositing the fiber, preheating by passing through a hot roll press or hot air,
At one time, it is manufactured as a matted product by hot pressing.

The powdered resin is characterized by a low risk of fire.However, the adhesion to the fiber is incomplete and dust is generated, and in the case of novolak resin, the odor is generated due to the decomposition of hexamine and the like. There was a disadvantage that the environment deteriorated.

In order to solve the above drawbacks, a water-soluble resole resin is used.

<Problems to be Solved by the Invention> However, the water-soluble resole resin has a low molecular weight (Mn = 500).
(Less than), the resin penetrates into the fiber greatly, and high molecular weight (Mn = 500 or more) shortens the gelation time, does not disperse evenly into the fiber, or preheats the hot air during production. In this case, there was a drawback that the fiber board of good strength could not be obtained in any case, for example, when the curing progressed remarkably at the time of (B-stage conversion) and density unevenness occurred.

<Means for Solving the Problems> The present inventors have conducted intensive studies in view of the above circumstances, and as a result, a fiberboard manufactured using an aqueous dispersion of a thermosetting resin has been found to be a conventional powdery or water-soluble fiberboard. It has been found that the strength is higher than that of a molded board manufactured using a phenolic resin of the present invention, and the present invention has been completed.

That is, the present invention provides a method for dry-producing a fiberboard, which comprises applying an aqueous dispersion of a resol-type phenol resin having a gelation time at 150 ° C. of 30 to 180 seconds to organic fibers and drying the resultant, followed by molding. Is provided.

Dry manufacturing method of the fiber board in the present invention,
Any known and commonly used dry manufacturing method can be adopted and is not particularly limited.

For example, (1) an aqueous dispersion of a thermosetting resin as a binder is attached to the fibers, and (2) the fibers to which the aqueous dispersion of the resin is attached (hereinafter referred to as resin-containing fibers) are fixed in a dryer or the like. Dry uniformly to obtain a water content of (3)
The material thus obtained is deposited, and the material is preheated (B-staged) by heat to obtain a matted product.
(4) The matted product may be hot-pressed while appropriately degassing.

The organic fiber according to the present invention is a fiber made of an organic compound, and examples thereof include wood fibers, natural fibers such as cotton, hemp, silk, and wool, and synthetic fibers such as nylon, polyester, polyurethane, rayon, and triacetate. .
Among them, wood fibers such as cellulose and lignin are preferred.
These organic fibers may be used alone or in combination of two or more.

The aqueous dispersion of the resol-type phenolic resin of the present invention is an aqueous dispersion of a known and commonly used resol-type phenolic resin, for example, using a dispersant such as a protective colloid or a surfactant during or after the synthesis of the resin. An aqueous dispersion dispersed in an aqueous medium is exemplified.

Aqueous dispersion of resole type phenol resin, since the resin component has a fine particle shape of 0.1 to 20 μm, when spray-mixed with wood fiber, permeation into the material is suppressed and has excellent adhesive performance . In particular, when a cellulosic protective colloid is used to disperse the resin in an aqueous medium, the adhesion between the resin and the fibrous substance becomes complete even in a water-containing state due to its adhesiveness, and the water-containing state is reduced. Is preferred because the adhesiveness decreases and the uniform dispersibility with the fiber substance becomes particularly excellent.

Resol-type phenolic resin has good fluidity of the resin at the time of hot-press molding, and the obtained fiberboard has high strength and hardly causes blistering. Type phenolic resins are particularly preferred.

The amount of the aqueous dispersion of the resin adhering to the organic fibers is determined by the type of the organic fibers used and the target strength of the fiber board, and is not particularly limited, but is 5 to 20% by weight based on the weight of the fibers (in terms of dry weight). (Resin solid content) is preferable because the drying time during the production of the fiber board is short and the obtained board has high strength. Examples of the method of attaching the aqueous dispersion of the resin to the fibers include a method of directly pouring and mixing the defibrated fibers and a method of mixing while spraying the mixed and stirred fibers. There is no limitation, and any method may be used.

In order to improve the fluidity of the resin-containing fibers and the releasability of the fiber board during hot pressing, waxes may be used in combination with the aqueous dispersion of the resin. The wax is not particularly limited, and any known and commonly used wax can be used. For example, paraffin-based wax, silicon-based wax, fatty acid amides and derivatives thereof are mentioned, and the form is preferably an emulsified aqueous solution. Among them, an aqueous paraffin emulsion is particularly preferable. The amount of wax added
Usually, it is 0.1 to 10% by weight based on the resin (solid content), and preferably 1 to 8% by weight from the viewpoint of improving the fluidity of the resin-containing fiber and excellent in releasing property of the obtained fiber board.

In order to improve water resistance and durability, an aqueous dispersion of the resin may be mixed with a silane coupling agent.
The silane coupling agent is not particularly limited,
Examples include vinyl, amino, epoxy, chlor, methacryloxy, and mercapto types. Among them, amino silane coupling agents are particularly preferred. The addition amount of the silane coupling agent is 0.1-5% by weight with respect to the resin (solid content), and is preferably 0.2-3% by weight in that the obtained fiberboard is excellent in improving the water resistance and durability strength.
It is.

If necessary, a conventional powdery phenol resin may be used in combination with the aqueous dispersion of the resol-type phenol resin.

Further, in addition to the above-mentioned waxes, silane coupling agents, and powdery phenolic resins, coloring agents, flame retardants, antioxidants, insect repellents, preservatives, water / oil repellents, water repellents, etc. Various additives such as soiling agents and fragrances may be used in combination as needed.

When various additives such as the above waxes and silane coupling agents are used, they may be mixed with an aqueous dispersion of the resin in advance and then adhered to fibers, or the aqueous dispersion of the resin and the additive may be used. Any method may be adopted, such as attaching the resin aqueous dispersion to the fibers separately, and then attaching the additives after the resin aqueous dispersion is attached to the fibers.

The drying of the resin-containing fibers in the above (2) may be performed using a usual dryer or a mixer for drying. Drying is preferably performed under conditions such that the water content of the resin-containing fiber is 8 to 20%.

In the above (3), any ordinary apparatus can be used for depositing the material. Examples of such an apparatus include a fleece molding machine and an air filter molding machine. The preheating treatment is not particularly limited as long as heat is applied to the material, and examples thereof include a method of irradiating infrared rays and a method of blowing hot air. Above all, a method of blowing hot air at 130 to 150 ° C. is simple and preferable. In this process, a matted product is manufactured, and the matted product usually has a thickness of 15 to 30 mm and an apparent specific gravity of 0.05 to 0.2 g / m ³ .

In the manufacturing method of the present invention, the mat board is manufactured once and then hot-pressed to produce a fiber board (that is, the method of going through the step (3)), or the material is directly hot-pressed. To produce a fiberboard. The conditions for hot pressing are not particularly limited, but are usually 180
230230 ° C., pressure 30-40 kg / cm ² , pressurization time 30-90 seconds. It is needless to say that gas is appropriately vented during hot pressing. The fiber board finally obtained in this way usually has a thickness of 2-3 mm and a specific gravity of 0.70-1.0 g / m ³ .

The fiber board obtained by the production method of the present invention can be used for various uses such as interior materials for automobiles, interior materials for houses, door panel materials, furniture panel materials and ceiling materials.

Next, examples of the present invention will be described. Hereinafter, unless otherwise specified, “parts” means “parts by weight” and “%” means “% by weight”.

Example 1 Plyofen PE-201 (water dispersion of resole type phenol resin manufactured by Dainippon Ink and Chemicals, Inc., 47% solid content, average particle size 2 μm, 150 μm) Using a spray device, 27 parts of a gelling time at 90 ° C. (90 seconds) were spray-sprayed onto 100 parts of a wood fiber (in terms of dry weight) to adhere. After that, put it in a mixer for drying,
The water content was adjusted to 12%. Next, after depositing this material through a fleece molding machine and an air filter molding machine, a hot air of 130 ° C is passed from the top and preheated,
A matted product having a thickness of about 30 mm and an apparent specific gravity of about 0.15 g / cm ³ was obtained. After that, degassing was performed once after 15 seconds at a temperature of 210 ° C., a pressure of 30 kg / cm ² , a time of 60 seconds, and a gas pressure of 15 seconds, and a fiber board having a thickness of 2.5 mm and a specific gravity of 0.80 g / cm ³ was obtained. The working environment and the mixing and dispersing properties of the wood fiber and the resin were all very good. The releasability of the fiberboard was good.

Example 2 2 parts of paraffin emulsified aqueous solution (solid content: 30%) was mixed with 27 parts of Plyofen PE-201, which was previously diluted with water and adjusted to a solid content of 30%, and was mixed with wood fiber (dry) using a spray device. (Conversion) Sprayed and attached to 100 parts. After that, it is put into a mixer for drying and the moisture content is 12
%. Next, after passing through a fleece molding machine and an air filter molding machine to deposit this material, it is preheated by passing 130 ° C. hot air from above, and the thickness is about 30 m.
m, a matted product having an apparent specific gravity of about 0.15 g / cm ³ was obtained. After that, temperature 210 ° C, pressure 30kg / cm ² , time 60 seconds, degassing 1
Performed once after 5 seconds and hot pressed, thickness 2.5mm, specific gravity 0.80g / cm
I got ³ fiber boards.

The working environment and the mixing and dispersing properties of the wood fiber and the resin were all very good. The releasability of the fiberboard was also very good.

Example 3 0.04 part of an amino-based silane coupling agent was mixed with 27 parts of Plyofen PE-201, which had been diluted with water in advance and adjusted to a solid content of 30%, and was mixed with 100 parts of wood fiber (dry equivalent) using a spray device. Sprayed and adhered. Thereafter, this was put into a mixer for drying and adjusted so that the water content became 12%. Next, fleece forming machine, after depositing the material through the air filter forming machine, preheating treatment vented hot air at 130 ° C. from the top, a thickness of about 30 mm, a mat of bulk density about 0.15 g / cm ³ The product was obtained. Then the temperature 210
° C., a pressure 30kg / cm ^2, time 60 seconds, heat molding type performed once vented after 15 seconds to give a thickness of 2.5 mm, a fiber board having a specific gravity of 0.80 g / cm ^3.

The working environment and the mixed dispersibility of the wood fiber and the resin were all very good. The releasability of the fiberboard was good.

Example 4 2 parts of paraffin emulsified aqueous solution (solid content: 30%) was added to 27 parts of Plyofen PE-201, which was previously diluted with water and adjusted to a solid content of 30%, and an amino-based silane coupling agent was added.
04 parts were mixed, and this was spray-sprayed and attached to 100 parts of wood fiber (dry equivalent) with a spray device. Thereafter, this was put into a mixer for drying and adjusted so that the water content became 12%. Next, after passing through a fleece molding machine and an air filter molding machine to deposit this material, a hot air of 130 ° C. is passed from the top to perform a preliminary heating treatment, a thickness of about 30 mm, an apparent specific gravity of about 0.15
A matte product of g / cm ³ was obtained. After that, temperature 210 ° C, pressure 30
After 15 seconds, degassing was performed once after 15 seconds with a pressure of kg / cm ² for 60 seconds to obtain a fiber board having a thickness of 2.5 mm and a specific gravity of 0.80 g / cm ³ .

The working environment and the mixed dispersibility of the wood fiber and the resin were all very good. The releasability of the fiberboard was also very good.

Example 5 An aqueous dispersion of a resole resin (solid content 47%, average particle size 2)
μm, gelation time at 150 ° C for 50 seconds) and diluted with water to obtain a solid content of 30
After adjusting to 27%, this 27 parts was spray-sprayed and attached to 100 parts of wood fiber (dry equivalent) using a spray device. Thereafter, this was put into a mixer for drying and adjusted so that the water content became 12%. Next, after passing through a fleece molding machine and an air filter molding machine to deposit this material, 130 ° C.
Hot air was ventilated and preheated to obtain a matted product having a thickness of about 30 mm and an apparent specific gravity of about 0.15 g / cm ³ . Then the temperature 210
C., pressure 30 kg / cm ² , time 60 seconds, degassing was performed once after 15 seconds, and hot pressing was performed to obtain a fiber board having a thickness of 2.5 mm and a specific gravity of 0.80 g / cm ³ .

The working environment and the mixed dispersibility of the wood fiber and the resin were all very good. The releasability of the fiberboard was good.

Example 6 An aqueous dispersion of a resole resin (solid content 47%, average particle size 2.
5μm, gelation time at 150 ° C 170 seconds) diluted with water
After adjusting to 0%, 27 parts were spray-sprayed and attached to 100 parts of wood fiber (dry equivalent) using a spray device. After that, put it in a mixer for drying, the moisture content is 12%
It was adjusted to become. Next, after passing through a fleece molding machine and an air filter molding machine to deposit this material,
130 ° C hot air is ventilated and pre-heat treated, about 30mm thick,
A matted product having an apparent specific gravity of about 0.15 g / cm ³ was obtained. afterwards,
A temperature of 210 ° C., a pressure of 30 kg / cm ² , a time of 60 seconds and a degassing were performed once after 15 seconds, followed by hot press molding to obtain a fiber board having a thickness of 2.5 mm and a specific gravity of 0.80 g / cm ³ .

The working environment and the mixed dispersibility of the wood fiber and the resin were all very good. The releasability of the fiberboard was also good.

Comparative Example 1 A commercially available water-soluble resole resin (solid content 50%, gelling time at 150 ° C. 90 seconds) was diluted with water to adjust the solid content to 30%, and then the wood fiber (dry conversion) was obtained using a spray device. 100
A mat having a thickness of about 30 mm and an apparent specific gravity of about 0.15 g / cm ³ was obtained in the same manner as in Example 1 except that the composition was sprayed and adhered to the portion. After that, degassing was performed once after 15 seconds at a temperature of 210 ° C., a pressure of 30 kg / cm ² , a time of 60 seconds, and a gas pressure of 15 seconds, and a fiber board having a thickness of 2.5 mm and a specific gravity of 0.80 g / cm ³ was obtained.

The working environment was very good. Although the mixed dispersibility of the wood fiber and the resin was extremely poor, the releasability of the fiberboard was good.

Comparative Example 2 Commercially available powdered novolak resin (gelling time at 150 ° C. 90
Seconds, containing 10% hexamine. 8) 8 parts were spread and mixed with 100 parts of wood fiber (in terms of dry weight) to adhere. Thereafter, a matted product having a thickness of about 30 mm and an apparent specific gravity of about 0.15 g / cm ³ was obtained in the same manner as in Example 1 except that this material was deposited through a fleece molding machine and an air filter molding machine. Then the temperature 210
° C., a pressure 30kg / cm ^2, time 60 seconds, vented heat molding is performed once after 15 seconds to give a thickness of 2.5mm density, the wood-based fiberboard 0.80 g / cm ^3.

The working environment was extremely bad with dust. The resin did not uniformly adhere to the wood fibers, and the mixing and dispersibility was extremely poor.
In addition, a powder drop phenomenon was also observed. The release properties of the fiberboard were somewhat poor.

Comparative Example 3 Commercial powdery resole resin (gelling time at 150 ° C. 90
Seconds) 8 parts are spread on 100 parts of wood fiber (in dry conversion), mixed and adhered. Then, Example 1 was repeated except that this material was deposited through a fleece molding machine and an air filter molding machine.
A mat having a thickness of about 30 mm and an apparent specific gravity of about 0.15 g / cm ³ was obtained in the same manner as described above. After that, the temperature was 210 ° C., the pressure was 30 kg / cm ² , the time was 60 seconds, the gas was vented once after 15 seconds, and hot pressing was performed.
A wood fiberboard having a thickness of 2.5 mm and a specific gravity of 0.80 g / cm ³ was obtained.

The working environment was extremely bad with dust. The resin did not uniformly adhere to the wood fibers, and the mixing and dispersibility was extremely poor.
In addition, a powder drop phenomenon was also observed. The releasability of the fiberboard was also somewhat poor.

The appearance and the normal bending strength of the fiber boards obtained in Examples and Comparative Examples were measured below, and the results are shown in Table 1.

<Effect of the Invention> The dry production method of the fiberboard of the present invention uses an aqueous dispersion of a resol-type phenol resin, so that the strength is remarkably enhanced as compared with a conventional fiberboard using a powdery or water-soluble phenol resin. When a silane coupling agent is used in combination, the strength can be further improved, and when waxes are used in combination, the releasability at the time of molding the fiber board can be improved.

Since the fiberboard produced by the method of the present invention has high strength, it can be used for various uses such as interior materials for automobiles, interior materials for houses, door panel materials, furniture panel materials and ceiling materials.

Claims (4)

(57) [Claims] 1. The method according to claim 1, wherein the gelation time of the organic fiber at 150 ° C. is 30.
A dry production method of a fiber board, comprising applying an aqueous dispersion of a resol-type phenol resin for up to 180 seconds, drying, and then molding. 2. The method according to claim 1, wherein the organic fibers are wood fibers. 3. The method according to claim 1, wherein the wax is used in combination with a resol type phenol resin. 4. The method according to claim 1, wherein the silane coupling agent is used in combination with a resol type phenol resin.