JPH0655507A - Modified wooden fiber board and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain wooden fiber board excellent in flame retardancy and smokeproofness. CONSTITUTION:In wooden fiber, an insoluble and incombustible inorganic compound is formed by impregnatingly reacting first liquid with second liquid. Further, the mixed water solution of phosphate and borate is infiltrated in the resultant wooden fiber. Thus, the wooden fiber, in lumina and/or on wall surfaces or outer peripheries of lumina of which water insoluble and incombustible inorganic compound, phosphate borate are filled, adhered or fixed, is obtained. By integrally forming the incombustibly treated wooden fibers through adherent substance, the modified wooden fiber board concerned is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved wood fiber board made of wood fibers which have been subjected to a non-combustible treatment and a method for producing the same.

[0002]

2. Description of the Related Art Techniques for making flame-retardant by dispersing and fixing an incombustible inorganic compound in the cell pores peculiar to wood in the state of a rod, plate or veneer of wood have been conventionally known (JP-A-61-244502).
However, in this known technique, it is necessary to disperse a non-combustible inorganic compound in wood in a bar, plate or veneer state of 40% or more based on the absolute dry weight of wood, In order to satisfy this requirement, it had to be dipped in a nonflammable inorganic compound solution for a long time depending on the size of the cross-sectional shape. Further, even after being immersed for a long time, it was difficult to uniformly disperse the wood even though the wood was largely impregnated into the outer circumference. Furthermore, since the powdery non-combustible inorganic compound adheres to the outer peripheral portion of the wood and impairs cosmetic properties, it cannot be used as a product as it is, and it is necessary to remove it by means such as washing with water. However, it is uneconomical since it is difficult to recover the removed non-combustible inorganic compound, and a waste liquid treatment step is required.

In view of these problems, the present applicant has
By impregnating wood fibers with the first liquid and the second liquid,
A water-insoluble non-combustible inorganic compound produced by these reactions is filled, adhered or fixed to the cell pores and / or the inner wall surface of the cell pores of the wood fiber, and the wood fiber is integrally bonded and molded to form a non-combustible fiber board. A technique for obtaining the above has been previously proposed (JP-A-3-27199). According to this technique, the non-combustible treatment can be performed within a relatively short time, the non-combustible inorganic compound can be dispersed and fixed substantially uniformly over the whole fiber board, and the cosmetic property is impaired. It is possible to achieve the operational effects such as no occurrence.

[0004]

DISCLOSURE OF INVENTION Problems to be Solved by the Applicant As a result of further experiments on the non-combustible fiber board according to the above-mentioned proposal,
When attempting to burn this fiberboard in a fireproof test, etc., although an excellent effect is observed regarding flame retardancy,
It became clear that a lot of smoke was generated. So the first
When the liquid removal and water washing treatment was performed after the reaction treatment of the liquid and the second liquid, smoke was considerably suppressed, but the flame retardancy was significantly reduced.

Although the reason for this is not always clear, it is practically difficult to completely carry out the reaction of the first liquid and the second liquid. Therefore, for example, as the first liquid or the second liquid, M is used.
When a chloride aqueous solution such as gCl ₂ or CaCl ₂ is used,
It is presumed that chlorine ions remain as unreacted components, which contributes to the improvement of flame retardancy but has an adverse effect on smoke resistance.

[0006]

Therefore, the present invention further improves on the prior art by the applicant of the present invention, in which unreacted components after the reaction treatment with the first liquid and the second liquid remain in the wood fiber. A water-insoluble non-combustible inorganic compound produced by impregnating a first liquid and a second liquid, which is intended to provide a fibrous plate having a flame-retardant property and a smoke-proof property. , Phosphate and borate are filled, adhered or fixed to the cell pores and / or the inner wall surface of the cell pores,
Further, the improved wood fiber board is characterized in that wood fibers adhered or fixed to the fiber surface are molded and integrated via an adhesive substance.

Further, the present invention is to provide a method capable of producing the above improved wood fiber board,
A wood fiber having cell pores is impregnated with a first liquid, and then a second liquid that produces a water-insoluble incombustible inorganic compound by mixing with the first liquid is impregnated with the water-insoluble product. The non-combustible inorganic compound of (1) is filled in or adhered to or fixed to the cell pores and / or the inner wall surface of the cell pores of the wood fiber, and the wood fiber is further washed with liquid, and then the wood fiber further contains a mixture of phosphate and borate. A method for producing an improved wood fiber board, which comprises impregnating 3 liquids and molding and integrating the wood fibers thus obtained through an adhesive substance.

The wood fibers used are, for example, pine, cedar, cypress, and other softwood materials, or rawan, capol, chestnut, poplar, and other hardwood materials, which are then defibrated according to a conventional method to give a water content of 20% or less. It is preferably dried to 10% or less. This wood fiber has a length of 1 to 30 mm and a diameter of 2 to 3
Most of them are about 00μ. This wood fiber has a shape in which conduits and temporary conduits or cells are bundled, and the cell wall at the outer periphery of the fiber is often torn or cracked.

The water-insoluble nonflammable inorganic compound is produced and filled by reacting the first liquid and the second liquid in the pores of the dried wood fiber, the pores of the conduit pores, or the inner wall of the cell pores. By adhering or adhering the non-combustible inorganic compound in a layered manner along with, and further adhering or adhering the non-combustible inorganic compound to the outer peripheral portion of the wood fiber, the first stage non-combustible treatment is performed. This first stage incombustibility treatment can be performed by the following steps.

That is, the wood fiber is sufficiently dipped in the aqueous solution (first liquid) of the water-soluble inorganic salt to impregnate it. On this occasion,
By impregnating under reduced pressure or pressure, the impregnation into the wood fiber can be carried out more effectively. In addition, the wood fiber is brought to a high water content state without being dried, or after it is once dried, it is immersed in water or warm water to absorb water to make it saturated, and then it is immersed in the first liquid for diffusion impregnation. Is also good.

The first liquid is MgCl ₂ , MgB
_{r 2, MgSO 4 · H 2} O, Mg (NO 3) 2 · 6H 2
O, CaCl ₂ , CaBr ₂ , Ca (NO ₃ ) ₂ , Ba
An aqueous solution of an alkaline earth metal salt such as Cl ₂ .2H ₂ O, BaBr ₂ , Ba (NO ₃ ) ₂ or AlCl ₃ , AlB
_{r 3, Al 2 (SO 4} ) 3, Al (NO 3) 3 · 9H 2
An example is an aqueous solution of a metal salt such as O or ZnCl ₂ .

Next, the first liquid is removed to remove the excess first liquid.
The liquid is drained. The deliquoring process is performed, for example, by centrifugal deliquoring. By removing the surplus first liquid, it is possible to prevent the non-combustible inorganic compound from being excessively generated in the outer peripheral portion of the wood fiber, and to improve the diffusion impregnation of the aqueous solution to be impregnated next.

Then, a compound liquid (second liquid) which reacts with the first liquid to produce a water-insoluble non-combustible inorganic compound is added to and mixed with or is immersed in the wood fiber by using a blender, a spray or the like. The wood fiber is impregnated with the second liquid.

The second liquid is (NH ₄ ) ₂ C
O ₃ , (NH ₄ ) ₂ SO ₄ , (NH ₄ ) ₂ HPO ₄ ,
Examples thereof include ammonium salts such as (NH ₄ ) H ₂ PO ₄ and NH ₄ BO ₂ .

By coating and impregnating the second liquid, the first liquid and the second liquid react in the wood fiber to produce a water-insoluble non-combustible inorganic compound. As the non-combustible inorganic compound produced,
Calcium compounds such as magnesium phosphate, calcium phosphate, barium phosphate, aluminum phosphate, magnesium borate, magnesium carbonate, calcium carbonate, zinc phosphate, barium carbonate, calcium nitrate, barium nitrate, magnesium compounds, aluminum compounds, barium compounds, Examples thereof include zinc compounds. After completion of the reaction, the second liquid is drained.

Since the non-combustible inorganic compound produced is insoluble in water, it is filled, adhered or fixed to the inside of the cell pores of the wood fiber or the inner wall of the cell pore and the outer periphery of the wood fiber after drying. As a result, even if the cell wall at the outer peripheral portion of the wood fiber contains cracks or cracks, the nonflammable inorganic compound exists in such a manner as to block or fill the cracks.

The non-flammable inorganic compound is preferably mixed in the wood fiber at a ratio of 33% by weight or more,
Below this, sufficient fire protection cannot be obtained. In addition, in order to increase the reaction efficiency between the first liquid and the second liquid,
The liquid is added and mixed in a heating atmosphere, preferably at 40 ° C. or higher,
More preferably, it is carried out at a temperature of 50 ° C. or higher.

In the above-mentioned first stage incombustibility treatment,
The treatment order of the first liquid and the second liquid is not limited, and the second liquid may be impregnated first.

The wood fiber thus obtained, in which the water-insoluble non-combustible inorganic compound is filled, adhered or fixed to the cell pores or the inner wall of the cell pores and the outer periphery of the fiber, is washed with liquid to remove excess non-combustibility. The first inorganic liquid and the second liquid remaining in an unreacted state are removed while removing the inorganic compound. For example, when BaCl ₂ and (NH ₄ ) ₂ HPO ₄ are used as the first liquid and the second liquid, Ba ₂ is used as the water-insoluble nonflammable inorganic compound.
(PO ₄ ) ₂ and BaHPO ₄ are produced, and at the same time, as unreacted components of the first liquid and the second liquid, chlorine ions (C 4
l ^-) and ammonium ion (NH ⁺⁾ but is left, chloride ion is removed by deliquored washing, smoke effect is improved.

Then, as a second stage incombustibility treatment, an aqueous solution (third liquid) of a mixture of phosphate and borate is further impregnated. Ammonium salt is preferable as the phosphate in the third liquid, for example, (NH ₄ ) H ₂ PO ₄ , (NH ₄ ).
₂ HPO ₄ , (NH ₄ ) ₃ PO _{4 and the} like are exemplified, and examples of the borate include KBO ₂ , metaborate such as NaBO ₂ (NH ₄ ) BO ₂ , LiB ₄ O ₇ , K ₂ B ₄ O ₇ , and Na. ₂ B
Tetraborate such as ₄ O ₇ , (NH ₄ ) ₂ B ₄ O ₇ , and (NH
₄ ) Pentaborates such as B ₅ O ₈ are exemplified.

By further impregnating the third liquid which is an aqueous solution of these mixtures, the inorganic compounds in the first liquid which remain in the wood fibers in an unreacted state after the dewatering and water washing are completely reacted. Let Since phosphate and borate coexist in the third liquid, a part of the first liquid remaining in the wood fiber in an unreacted state reacts with the phosphate and the other reacts with borate. However, substantially all of the first liquid can be reacted by the combined effect of these reactions, and the residue in the unreacted state can be prevented.

At the same time, the phosphate and borate in the third liquid are impregnated or adhered to the wood fiber as they are,
It greatly contributes to the improvement of flame retardancy.

After the impregnation with the third liquid, the excess third liquid is removed. After the deliquoring treatment, it is dried to have a water content of 25% or less, preferably 7 to 15%. Thus, water-insoluble non-combustible inorganic compounds, phosphates and borates are filled, adhered or fixed in the cell pores or the inner wall of the cell pores and the outer peripheral portion of the fiber, and the wood fiber and its outer peripheral portion are impregnated with the fireproofing compound and A non-combustible treated wood fiber in an attached state is obtained.

[0024] The non-combustible wood fiber is put into a mixing device, and a urea resin adhesive, a phenol resin adhesive, a melamine resin adhesive, an epoxy resin adhesive, an isocyanate / vinyl acetate resin adhesive is added. The agent or the modified synthetic resin adhesive and the sizing agent are added and mixed. In order to further improve the fireproof performance of the resulting wood fiber board, an adhesive containing a fireproof compound may be used.

The non-combustible wood fiber to which an adhesive is added and mixed is blown and introduced into a forming device to form a continuous wood fiber mat having a constant thickness on the conveying device. The wood fiber mat is cut into a regular size, then inserted into a hot press and thermocompressed to obtain the improved wood fiber board of the present invention.

[0026]

【Example】

Example 1 A chip of radiata pine was heated at 160 ° C. for 7 hours.
It was boiled at 5 kg / cm ² for 5 minutes for degreasing and softening. The chips were defibrated with a defibrillator refiner, and the obtained wood fiber was dried.

This wood fiber was dipped in a 17% by weight aqueous solution of barium chloride (first liquid) at 50 ° C. for 1 hour to carry out a diffusion treatment and then drained. This was dried with hot air to adjust the water content to 7%. This wood fiber is put into a blender, and a 28% by weight aqueous solution of diammonium hydrogen phosphate (second liquid) is added and mixed to obtain water-insoluble phosphoric acid in pores such as cell pores of the wood fiber or in the outer periphery of the wood fiber. After a nonflammable inorganic compound consisting of barium and barium hydrogen phosphate was produced, it was drained and washed with water.

Further, this wood fiber was put into a blender, and a mixed aqueous solution (third liquid) of 28% by weight of diammonium hydrogen phosphate and 3.8% by weight of sodium tetraborate was added and mixed.

Thereafter, the water content was adjusted to 6% by hot air drying. The weight increase rate of wood fiber by this incombustibility treatment is 88
%Met.

In the mixer, 4.5% by weight of wax was added to the wood fibers by spraying and mixing in the mixer. Next, in another mixer, 10% by weight of a phenol resin adhesive was added and mixed with the wood fiber.

This wood fiber is put into a duct and blown,
A forming apparatus was used to drop and deposit on a screen conveyor to form a wood fiber mat.

After cutting this wood fiber mat to a predetermined size, it was put into a hot press and thermoformed at 200 ° C. for 2 minutes to obtain an improved wood fiber board of the present invention. <Comparative Example 1> A chip of radiata pine was heated at 160 ° C.
It was boiled at 5 kg / cm ² for 5 minutes for degreasing and softening. The chips were defibrated with a defibrillator refiner, and the obtained wood fiber was dried.

This wood fiber was dipped in a 17% by weight aqueous solution of barium chloride (first liquid) at 50 ° C. for 1 hour, diffused, and then dewatered. This was dried with hot air to adjust the water content to 7%. This wood fiber is put into a blender, and a 28% by weight aqueous solution of diammonium hydrogen phosphate (second liquid) is added and mixed to obtain water-insoluble phosphoric acid in pores such as cell pores of the wood fiber or in the outer periphery of the wood fiber. After a nonflammable inorganic compound consisting of barium and barium hydrogen phosphate was produced, it was drained and washed with water. Without adding and mixing a mixed aqueous solution (third liquid) of diammonium hydrogen phosphate and sodium tetraborate to this wood fiber, it was immediately put into a mixer, and a wood fiber board was obtained by the same method as in the following examples. It was

Table 1 shows the results of a fireproof test using the wood fiber boards obtained in Example 1 and Comparative Example 1.

[Table 1]

According to the present invention, it is possible to obtain a wood fiber board having excellent fireproofing performance and smoke eliminating performance.

Claims (2)

[Claims] 1. A water-insoluble noncombustible inorganic compound produced by impregnating a first liquid and a second liquid,
Phosphate and borate are filled in or attached to or fixed to the cell pores and / or the inner wall surface of the cell pores, and the wood fibers adhered or fixed to the fiber surface are integrally formed through an adhesive substance. An improved wood fiber board characterized in that 2. A wood fiber having cell pores is impregnated with a first liquid, and then with a second liquid for mixing and reacting with the first liquid to produce a water-insoluble non-combustible inorganic compound, The produced water-insoluble non-combustible inorganic compound is filled, adhered or fixed to the cell pores and / or the inner wall surface of the cell pores of the wood fiber, and after washing with liquid to remove water, phosphate and borate are further added to the wood fiber. A method for producing an improved wood fiber board, which comprises impregnating a third liquid containing the mixture of 1. and molding and integrating the wood fibers thus obtained through an adhesive substance.