JPH0663907A - Manufacture of modified wood - Google Patents

Abstract

PURPOSE:To provide a manufacture of modified wood with an excellent moisture resistance by efficiently removing water soluble compounds, in a manufacture of modified wood for producing insoluble compounds by reacting a cation- containing compound and an anion-containing compound within wood. CONSTITUTION:Impregnated wood is heated and compressed, which has an insoluble compound and a water soluble compound produced by reacting a cation-containing compound and an anion-containing compound, in raw material wood.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing modified wood used for building materials and the like.

[0002]

2. Description of the Related Art Conventionally, an insoluble non-combustible inorganic substance has been used as a modification method for imparting flame retardancy, antiseptic / insect resistance, dimensional stability, water / moisture resistance, surface hardness, mechanical strength, and abrasion resistance to wood. There are known methods such as compounding with a compound, compounding with a functional resin, chemical modification by a chemical bond, and impregnation with a chemical such as a preservative.

The compounding with the insoluble non-combustible inorganic material is mainly carried out for the purpose of imparting flame retardancy, antiseptic / insect repellent property, and surface hardness, and among them, especially for flame retardancy, modification reaching a quasi non-combustible level. Wood has been obtained and is used as a material for fire doors and the like. The compounding with the above-mentioned functional resin is performed mainly for the purpose of imparting water / moisture resistance, surface hardness, mechanical strength, and abrasion resistance, and generally WP
Widely known as C. The chemical modification by the above-mentioned chemical bonding is mainly performed for the purpose of imparting dimensional stability and water / moisture resistance. For example, modified wood by acetylation is used as a water supply material for bathtubs and the like. Also,
The chemical impregnation is mainly performed for the purpose of imparting antiseptic / insect repellent properties and is widely used.

Among these modification methods for modifying natural wood, particularly in the modification method by the combination with the above-mentioned insoluble non-combustible inorganic material, as disclosed in, for example, JP-A-61-246003. , Modifying the wood by impregnating the natural raw material wood with two kinds of aqueous solutions containing cations and anions that react with each other to form an insoluble compound separately, and forming and fixing the insoluble compounds. It has been known. However, in this method for modifying wood, since the reaction between the cation-containing compound and the anion-containing compound occurs outside the wood, an insoluble compound is generated in the aqueous solution in the dipping tank, and as a result, the composition of the aqueous solution changes. there were.

As a method for solving the above-mentioned problems, for example, a cation-containing compound and an anion-containing compound are sprayed on the opposite surfaces of the raw material wood to be modified, and then an insoluble compound is formed and fixed in the wood. The method is effective. According to this method, since the reaction between the cation-containing compound and the anion-containing compound occurs from the center of the wood, modified wood with a high concentration of the insoluble compound in the center can be obtained, but the insoluble compound is formed and fixed in the wood. When making
Water-soluble compounds form in the wood. Since this water-soluble compound absorbs moisture in the atmosphere, there is a drawback in that the modified wood has poor moisture resistance. In order to remove this drawback, there is a method of removing the modified wood by immersing it in a solvent such as water,
This method requires long-term immersion to remove water-soluble compounds,
Not industrial.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above facts, and an object thereof is to modify a cation-containing compound and an anion-containing compound in wood to produce an insoluble compound. In a method for producing a quality wood, a water-soluble compound in impregnated wood is efficiently removed, and a method for producing a modified wood having good moisture resistance is provided.

[0007]

The method for producing modified wood according to the present invention is an impregnated wood containing an insoluble compound and a water-soluble compound produced in a raw wood by a reaction of a cation-containing compound and an anion-containing compound. Is heated and pressurized.

[0008]

[Function] An insoluble compound is formed and fixed in the wood by the reaction of the cation-containing compound and the anion-containing compound. When this insoluble compound is produced, by-products are produced and unreacted substances remain. According to the present invention, when the impregnated wood containing the insoluble compound and the water-soluble compound is heated and pressed, the voids are compressed. As a result, the aqueous solution of the water-soluble compound existing in the voids is left outside the wood for a short time. Spill out at. The moisture resistance of the modified wood is improved because the amount of water-soluble compounds in the wood is reduced.

The present invention will be described in detail below. The shape of the raw material wood for modification used in the present invention is not particularly limited, for example, log logs, lumber products, sliced veneer, plywood, etc. are used, and the area impregnated with the compound is compared with the volume of wood. Larger is preferable. There is no limitation on the species of the raw wood.

Prior to the impregnation of the cation-containing compound and the anion-containing compound, the raw material wood is impregnated with a solvent such as water. In this case, permeation to a saturated state is effective in increasing impregnation of the cation-containing compound and the anion-containing compound into the wood. The permeation rate of the solvent into the raw wood is preferably 80% or more, more preferably 100% or more, based on the absolute dry weight of the raw wood. The method of permeating the solvent is not particularly limited, but for example, underwater storage, steaming,
There are impregnation under reduced pressure, impregnation under pressure and the like.

In the impregnated wood used in the present invention, the water-soluble compound is formed at the same time as the insoluble compound formed by the reaction of the cation-containing compound and the anion-containing compound is fixed in the above-mentioned raw material wood. The insoluble compound that is produced and fixed in the wood is not particularly limited, but is determined according to the purpose of modification. When a nonflammable insoluble compound is produced, wood is rendered flame retardant, and when an insect repellent insoluble compound is produced, wood is rendered insect repellent. For example, for the purpose of flame retardancy, borate, phosphate, hydrogen phosphate, carbonate, sulfate, hydrogen sulfate, silicate, nitrate,
Hydrochloride etc. are mentioned. In order to generate and fix the insoluble compound in wood, a cation-containing compound containing a cation species forming the cation part of the insoluble compound and an anion containing compound containing an anion species forming the anion part of the insoluble compound are prepared. You can use it. The cation-containing compound and the anion-containing compound react with each other to produce an insoluble compound. One kind or two or more kinds of the insoluble compound may coexist in the wood, and is arbitrarily selected according to the composition of the desired insoluble compound to be generated in the wood.

As the cationic species of the insoluble compound,
Although not particularly limited, for example, Mg, Ca, Sr, B
Alkaline earth metal ions such as a, Al, Fe, Cu, C
Metal ions such as o, Ni, Mn, Pb, and Zn are included. Further, the anion species of the insoluble compound is not particularly limited, but for example, OH ⁻ , F ⁻ , Cl ⁻ , Br.
_{^{-, NO 3 -, CO 3}} 2-, BO 3 2-, PO 4 3-, SO 4
^{2- and} so on. These cation species and anion species may be one type, or two or more types may coexist as shown in the examples. Depending on the kind of cation and anion, it may form the cation part of the insoluble compound to be formed, or may form the anion part. Taking magnesium sulfate (MgSO ₄ ) as an example, SO ₄ ²⁻ becomes an anion species with respect to barium chloride (BaCl ₂ ),
With respect to diammonium hydrogen phosphate ((NH ₄ ) ₂ HPO ₄ ), Mg ⁺ becomes a cationic species. In selecting the cation-containing compound and the anion-containing compound, a combination that easily forms an insoluble compound in wood is preferable.

Wood is impregnated with the above-mentioned cation-containing compound and anion-containing compound. This impregnation method is not particularly limited, but for example, a method of spraying a powdery cation-containing compound and an anion-containing compound on opposite surfaces is
As described above, it is effective in that an insoluble compound can be produced in wood without producing an insoluble compound outside the wood. In this case, the insoluble compound forms in the center of the wood. To give an example of a specific method of impregnation, one side of the raw material wood sprayed with the cation-containing compound, and one side of the raw material wood sprayed with the anion-containing compound, the surface of the compound is directed in the same direction. , There is a method of alternately impregnating the raw material wood sprayed with the cation-containing compound and the raw material wood sprayed with the anion-containing compound, and this method can impregnate a plurality of raw wood materials at a time, thereby improving the production efficiency. It is effective as a good industrial method. The number of times the cation-containing compound or the anion-containing compound is impregnated is not particularly limited and is determined depending on the kind and amount of the desired insoluble compound.

After impregnating the above-mentioned cation-containing compound and anion-containing compound, heating is performed for curing. This heating method is not particularly limited. The heating accelerates the formation and fixation of the insoluble compound as the reaction between the cation-containing compound and the anion-containing compound proceeds in the wood. The temperature, time, method and the like of this curing condition are not particularly limited, and are appropriately determined depending on the type and amount of the insoluble compound produced. During the above curing, it is preferable that the solvent in the wood is not volatilized and the wood is not dried. This method is not particularly limited, and examples thereof include a method of sealing a raw material wood on which a cation-containing compound and an anion-containing compound are dispersed with a sheet.

An insoluble compound is produced and fixed in the impregnated wood impregnated with the above-mentioned cation-containing compound and anion-containing compound, and by-products and unreacted water-soluble compounds are also present in the wood.

In the present invention, the impregnated wood containing the insoluble compound and the water-soluble compound is heated and pressed. This pressure condition is set in a range where the impregnated wood is not destroyed by pressure. This temperature condition is also not particularly limited, and for example, a curing temperature at which an insoluble compound is produced is sufficient.
The heating and pressurizing time is also not particularly limited, and the number and thickness of the impregnated wood, the heating temperature, the pressure, the amount and type of the water-soluble compound to be generated, and the water-soluble compound are generated in the impregnated wood. It is appropriately determined depending on the position and the like. Due to this heating and pressurization, the voids in the wood are compressed, and the water-soluble compound existing in the voids flows out of the wood and is removed in a short time. In this case, the insoluble compound is due to insolubility,
It remains in the wood without spilling.

After the impregnation of the cation-containing compound and the anion-containing compound, formation / fixation of the insoluble compound, and removal of the water-soluble compound by heating under pressure, the wood surface is washed with water and dried, if necessary. Then, the target modified wood is obtained.

[0018]

EXAMPLES Examples and comparative examples of the present invention will be given below.

Example 1 As raw material wood, water was previously used as a solvent to make it saturated.
A plurality of Agathis rotary veneers having a thickness of 1 mm and a size of 11 cm × 11 cm were prepared.

4.1 barium chloride (BaCl ₂ .2H ₂ O) was added as a cation-containing compound on the upper surface of the veneer.
9.3 g of barium hydroxide (Ba (OH) ₂ ) containing both cation species and anion species was uniformly dispersed. This veneer was used. On the upper surface of the remaining veneer, 4.1 g of magnesium sulfate (MgSO ₄ ) powder containing both cation and anion species.
Sprayed evenly. This veneer was used. These veneers,
.. were alternately laminated in this order with the surface to be sprayed facing upward, and a single plate that had not been sprayed was placed on top. The obtained single plate laminate was sealed and cured at 80 ° C. for 24 hours. At the time when this curing was completed, the sprayed cation-containing compound and anion-containing compound did not remain on the upper surface of the veneer, and the reaction was in a completed state. Next, 1.1 g of a powder of diammonium hydrogen phosphate ((NH ₄ ) ₂ HPO ₄ ) was uniformly dispersed as the anion-containing compound 1 on the cured veneers and both, and the veneers were laminated and sealed. And further cured at 80 ° C. for 24 hours.

Cation-containing compound and anion-containing compound
Impregnated with a compound, and barium sulfate (BaSO_Four), Phosphate
Rium (Ba₃(PO_Four)₂), Magnesium phosphate
(Mg ₃(PO_Four)₂) Insoluble compounds such as
Nesium (MgCl₂), Water-soluble compounds such as unreacted substances
The resulting impregnated wood is placed on a heating plate heated to a temperature of 80 ° C.
Insert, pressure 30kg / cm², Press for 1 minute
Pressed. An aqueous solution containing a water-soluble compound flows out onto the hot platen.
It was After the pressurization was completed, it was washed with water and dried to obtain a modified wood.
This modified wood was used as a test piece.

The content of the insoluble compound, the residual ratio of the water-soluble compound and the moisture absorption amount of this test piece were measured as moisture resistance.

The content rate was determined according to the following formula. - content _{(%) = {(W 2} -W 1) / W 1} × 100 · W 1 represents the absolute dry weight before the solvent penetration. · W ₂ represents the absolute dry weight of the resulting modified wood.

The residual rate of the water-soluble compound was measured as follows. The initial weight A of the above test piece was measured and then soaked in water for 48 hours, and the weight B after drying at 105 ° C. for 5 hours
To measure. The weight difference (AB) and the initial weight A were calculated as a ratio. -Residual rate (%) = {(A-B) / A} x 100 The amount of moisture absorption was measured as follows. The test piece of 11 cm square was treated at a temperature of 40 ° C. and a relative humidity of 75% for 48 hours.
The weight D when treated for 24 hours was measured, and this weight increase amount (D-C) was taken as the moisture absorption amount.

Examples 2 to 3 In Example 1, the types and thicknesses of the veneer, the types and spraying amounts of the cation-containing compound and the anion-containing compound, the curing conditions and the heating and pressurizing conditions were set to the conditions shown in Table 1 below. except,
Modified wood was obtained in the same manner as in Example 1. This modified wood was used as a test piece.

The content rate, residual rate and moisture absorption of this test piece were measured in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 1 In the same manner as in Example 1, a cation-containing compound and an anion-containing compound were impregnated to obtain an impregnated wood in which an insoluble compound and a soluble compound were produced. The impregnated wood obtained without pressure was washed with water and dried to obtain modified wood, which was used as a test piece.

The content rate, residual rate and moisture absorption of this test piece were measured in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 2 In the same manner as in Example 3, a cation-containing compound and an anion-containing compound were impregnated to obtain an impregnated wood in which an insoluble compound and a soluble compound were produced. The impregnated wood obtained without pressure was washed with water and dried to obtain modified wood, which was used as a test piece.

The content rate, residual rate and moisture absorption of this test piece were measured in the same manner as in Example 1. The results are shown in Table 2.

[0031]

[Table 1]

[0032]

[Table 2]

In Examples 1 and 2 and Comparative Example 1, the amounts of the cation-containing compound and the anion-containing compound sprayed were the same, and the curing conditions were the same. However, the residual ratio of the water-soluble compound and the amount of moisture absorption were small, which was excellent. Even though the amount of the cation-containing compound and the amount of the anion-containing compound sprayed and the curing conditions were the same in Example 3 and Comparative Example 2, the water-soluble compound remained in Example 3 depending on the presence or absence of pressure. Both the rate and the amount of moisture absorption were small, which was excellent.

[0034]

EFFECTS OF THE INVENTION According to the method of the present invention, a water-soluble compound can be efficiently removed in a method of producing modified wood in which a cation-containing compound and an anion-containing compound are reacted with each other in the wood to produce and fix an insoluble compound. Modified wood with good properties can be obtained.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoru Konishi 1048, Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Works Co., Ltd. (72) Kenji Ohnishi, 1048, Kadoma, Kadoma City, Osaka Prefecture 72) Inventor Arihiro Adachi 1048, Kadoma, Kadoma-shi, Osaka Prefecture Matsushita Electric Works Co., Ltd.

Claims (1)

[Claims] 1. A method for producing modified wood, characterized in that impregnated wood having an insoluble compound and a water-soluble compound produced by the reaction of a cation-containing compound and an anion-containing compound in the raw wood is heated and pressed.