JPH06218707A - Production of modified wood - Google Patents

Abstract

PURPOSE:To keep a flame retardance and a dimensional stability and enhance a moisture resistance by a method wherein one of a cation-containing compound and an anion-containing compound is spread on one surface of a material wood to be infiltrated and cured therein, the other compound is on the other surface, and an-additive reacting with a by-product and an unreacted substance to produce an insoluble compound is used. CONSTITUTION:A solvent, such as water, is penetrated into a material wood. A wood veneer 1 is formed by spreading a cation-containing compound on one surface of the material wood. A wood veneer 2 is separately formed by spreading an anion-containing compound, which is a guanidine salt, on one surface of the material wood. The wood veneers 1 with the cation-containing compound spread thereon and the wood veneers 2 with the anion-containing compound spread thereon are alternately laminated with the spread surfaces showing up, sealed, cured, and dried. An additive reacting with a insoluble compound is spread on either the veneers 1 or 2 with the cation- or anion- containing compound spread thereon. After the insoluble compound is produced and fixed, a soluble unreacted compound and others are washed by water to be removed, as required.

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. Methods such as compounding with, functional compounding, chemical modification by chemical bonding, and impregnation of chemicals such as preservatives have been carried out.

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 chemical bond 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 reforming methods for modifying natural wood,
Particularly, in the modification method by the combination with the insoluble incombustible compound, as disclosed in, for example, JP-A-61-246003, a cation and an anion which react with each other to form an insoluble incombustible compound are separately prepared. It is known to modify the wood by impregnating the natural raw material wood with the two kinds of aqueous solutions contained in the above solution in order to generate and fix the insoluble incombustible compound. However, in this method for modifying wood, a reaction between the cation-containing compound and the anion-containing compound occurs outside the wood, so that an insoluble incombustible compound is produced in the aqueous solution in the dipping tank, and as a result, the composition of both aqueous solutions changes. There was a problem.

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, a modified wood having a high concentration of the insoluble incombustible compound in the center can be obtained. By-products and unreacted substances are generated in the wood when it is generated and fixed.
Since these by-products and unreacted substances easily absorb moisture in the atmosphere, there is a problem in that the modified wood has poor moisture resistance.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned facts, and an object of the present invention is to improve flame retardancy, dimensional stability, and moisture resistance. To provide a method of manufacturing wood.

[0007]

The method for producing modified wood according to claim 1 of the present invention is as follows:
Generation of an insoluble compound by spraying, impregnating, and curing one compound of a cation-containing compound and an anion-containing compound on one side of the raw wood and the other compound on the other side, which react with each other to form an insoluble compound A soluble by-product produced at the same time, a drug that reacts with an unreacted product to form an insoluble compound is used as this drug.
It is characterized in that it contains a cation-containing compound, and the anion-containing compound is a guanidine salt, and further that an additive that reacts with the by-product and unreacted product to form an insoluble compound is used.

According to a second aspect of the present invention, the method for producing modified wood comprises the steps of reacting raw material wood with one of a cation-containing compound and an anion-containing compound that react with each other to produce an insoluble compound. On the other side, the other compound is sprayed on one side of the other raw material wood, and the surface on which the compound is spread is directed in the same direction, and the raw material on which the cation-containing compound is spread and the raw material on which the anion-containing compound is spread In the process of curing by alternately stacking with wood,
An additive that reacts with a by-product or an unreacted product to form an insoluble compound is sprayed and impregnated with at least one of a cation-containing compound and an anion-containing compound that forms the insoluble compound.

The method for producing modified wood according to claim 3 of the present invention is characterized in that a urea resin is used as an additive.

[0010]

According to the method for producing modified wood of the present invention, one of the cation-containing compound and the anion-containing compound, which reacts with each other to produce an insoluble compound, reacts with one of the raw woods to be modified. On the surface of, the other compound is sprayed on the other surface, impregnated, and cured to form a soluble by-product that is simultaneously formed with the formation of the insoluble compound, and an agent that reacts with the unreacted substance to form the insoluble compound, As this drug, a cation-containing compound is contained, the anion-containing compound is a guanidine salt, and further, since an additive which reacts with the above-mentioned by-product and unreacted product to form an insoluble compound is used, the compound sprayed is When it reaches the center of wood quickly, it reacts with soluble by-products and unreacted materials to form insoluble compounds. Therefore, the amount of the insoluble compound fixed inside the wood increases.

According to the method for producing modified wood of the present invention, for example, a cation-containing compound is contained as a drug which reacts with a soluble by-product or an unreacted product to produce an insoluble compound,
Since the anion-containing compound is a guanidine salt containing an anion species, it can efficiently produce an insoluble compound inside the wood, and as a result of reducing soluble by-products and unreacted compounds, it is water and moisture resistant. Is improved.

Furthermore, according to the method for producing modified wood of the present invention, since urea resin is used as an additive that reacts with by-products and unreacted materials to produce insoluble compounds, it is efficiently insoluble in the interior of wood. By-products and unreacted substances are fixed in the wood while the compound is produced or remains soluble, and as a result, water resistance and moisture resistance are further improved.

The present invention will be described in detail below. The shape of the raw material wood for reforming used in the present invention is not particularly limited, and for example, log logs, lumber products, sliced veneer, plywood, etc. are used, and the surface impregnated with the agent is compared with the volume of wood. And a wider one is preferable. There are no particular restrictions on the species of these raw woods.

In the present invention, a raw material wood is prepared by impregnating the raw material wood with a solvent such as water prior to impregnation with the cation-containing compound and the anion-containing compound. In this case, permeation to a saturated state is effective for improving the impregnation of the above compound into 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, and examples thereof include heat immersion, storage in water, steaming, impregnation under reduced pressure, and impregnation under pressure.

In the method for producing modified wood of the present invention, the insoluble compound produced and fixed in the wood is not particularly limited, but it is determined according to the purpose of the 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 flame retardancy, borate,
Examples thereof include phosphates, hydrogen phosphates, carbonates, sulfates, hydrogen sulfates, silicates, nitrates and hydroxides. 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.

The cation species constituting the cation portion of the insoluble compound is not particularly limited, but for example,
^{Mg 2 +, Ca 2+, Sr} 2+, Ba 2+ , etc. alkaline earth metal ^{ions, Al 3+, Fe 3+, Cu} 2+, Co 2+, Ni 2+,
Examples thereof include metal ions such as Mn ²⁺ , Pb ²⁺ and Zn ²⁺ .
Further, the anion species constituting the anion part of the insoluble compound is not particularly limited, but for example, OH ⁻ , F
^{-, Cl -, Br -,} NO 3 -, CO 3 2-, BO 3 2-,
Examples include PO ₄ ³⁻ and SO ₄ ²⁻ .

The above cation-containing compound and anion
The content of the compound is that the permeability of the raw material wood is the solubility of the compound,
Greatly left for deliquescent, source wood species, water content, curing conditions
As shown on the right, the anion-containing compound is a guanidine salt.
Other than that, it is not particularly limited, but cation-containing
Examples of the compound include MgSO 4._Four, BaCl₂, Mg
Cl₂, ZnCl₂, AlCl₃, CaCl₂, CaS
O_Four, Al (SO_Four) ₃Etc. are suitable. Anion included
Examples of the compound include guanidine sulfamate,
Guanidine phosphate and the like are suitable. Contains these cations
Let compounds and anion-containing compounds occur inside wood
Selected according to the composition of the desired insoluble compound
Be done. Two or more of these compounds coexist in wood
You may do it. The above cation-containing compound and anion
When selecting the compound to be contained, it becomes insoluble in the central part of the wood
Use a combination that facilitates the formation of compounds.

Urea resins such as melamine resins and urea resins are used as additives for reacting with the above-mentioned by-products and unreacted materials to form insoluble compounds. In addition, epoxy resins and phenol resins are also used. May be used. The resin as the main component and the curing agent, and the resin and the other additives are impregnated respectively to accelerate the reaction inside the wood. Additives that react with the above-mentioned by-products and unreacted substances to form insoluble compounds are also arbitrarily selected according to the composition of the desired insoluble compound to be generated inside the wood.

After spraying the cation-containing compound and the anion-containing compound on the opposite surfaces of the raw wood,
The method of impregnation is not particularly limited, but among them, the raw material wood sprayed with the cation-containing compound on one side, and the raw wood wood sprayed with the anion-containing compound on one side, the surface of the compound is sprayed. In the same direction,
There is a method of curing by alternately stacking raw material wood sprayed with a cation-containing compound and raw material wood sprayed with an anion-containing compound.This method enables curing of multiple raw wood materials at once, resulting in good production efficiency. It is effective as an industrial method.

When impregnating the compound, it is preferable to prevent the solvent in the wood from volatilizing and the wood from drying. This method is not particularly limited, and examples thereof include a method of sealing a raw material wood onto which the compound has been dispersed with a sheet.

In order to improve the durability and weather resistance of the modified wood, if necessary, the obtained modified wood is immersed in water or another suitable solvent and left in the wood. The soluble unreacted compounds, by-products and the like may be removed.

During curing, it is possible to accelerate the diffusion and reaction of the cation-containing compound and the anion-containing compound by a method such as temperature and physical action. For example,
As an example of a method of accelerating the reaction, a method of applying temperature from the outside is one example.

After the above-mentioned impregnation of the cation-containing compound and the anion-containing compound and the production / fixing of the insoluble compound are completed, the surface of the wood is washed with water, etc., if necessary, and dried to obtain the desired modified wood. obtain.

[0024]

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

Example 1 A process for producing a modified wood according to an example of the present invention will be described with reference to FIG.

In the first step, a wood veneer (1) sprayed with a cation-containing compound and another wood veneer (2) sprayed with an anion-containing compound are prepared. Next, in the second step, the wood-containing veneer (1) sprayed with the cation-containing compound prepared in the first step and another wood veneer (2) sprayed with the anion-containing compound were sprayed with the compound containing. Layers are stacked alternating side up. In the third step,
The wood veneer (1) on which the cation-containing compound was sprayed alternately in the second step and the other wood veneer (2) on which the anion-containing compound was sprayed were sealed at 40 ° C.,
It was aged for 24 hours and dried. The additive may be applied to either wood veneer (1) sprinkled with a cation-containing compound or to another wood veneer (2) sprinkled with an anion-containing compound. By following these steps in sequence, modified wood is obtained.

As a raw material wood, a 3 mm-thick Agatisu rotary veneer (1) which has been saturated with water as a solvent in advance.
A plurality of sheets of (2) and (2) were prepared.

Barium chloride (BaCl ₂ .2H ₂ O), which is a cation-containing compound, was uniformly sprayed on the upper surface of the veneer (1) at a rate of 1210 g / m ^{2 in} a powder state, and another veneer ( As an anion-containing compound on the upper surface of 2), guanidine sulfamate at a rate of 775 g / m ² , and on the upper surface of the veneer (2) as an additive, a methylol melamine resin at a rate of 600 g / m ² and uniformly. , And alternately stack these single plates in the order of (1), (2), (1) ...
The obtained single plate laminate was sealed and cured at room temperature of 40 ° C. for 24 hours. After the curing was completed, the wood was washed with water and dried to obtain modified wood.

The modified wood thus obtained was examined for the impregnation rate of insoluble compound, flame retardancy, moisture resistance and dimensional stability.

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 solvent penetration.

W ₂ represents the absolute dry weight of the obtained modified wood. Regarding the flame retardancy, a surface combustion test based on JIS-A-1321 was conducted, and those having performance equivalent to the flame retardant class 2 were represented by ◯, and those having performance equivalent to the flame retardant class 3 were represented by Δ. The results are shown in Table 2.

Moisture resistance is evaluated by the weight of absorbed water, and the smaller the weight value, the better. Next, the dimensional stability is evaluated by the anti-swelling rate (ASE), and the higher the anti-swelling rate, the better. The anti-swelling ratio was determined according to the following formula.

Anti-swelling rate (%) = {(S ₁ −S ₂ ) / S ₁ } × 100 S ₁ represents the swelling rate of the raw wood. S ₁ was calculated based on the following formula by measuring the dimension A of the raw material wood after being dried, and the dimension B of the raw material wood after being immersed in water for 72 hours in a vacuum state.

S ₁ (%) = {(B−A) / A} × 100 S ₂ represents the swelling ratio of the modified wood. S ₂ was obtained by measuring the dimension C of the modified wood after absolutely drying and the dimension D of the modified wood after soaking it in water for 72 hours in a vacuum state, and calculating based on the following formula.

S ₂ (%) = {(D−C) / C} × 100 The impregnation rate of the insoluble compound in the modified wood obtained in Example 1,
The results of flame retardancy, moisture resistance, and dimensional stability are shown in Table 2.

Examples 2 to 5 and Comparative Examples 1 to 3 In Example 1, except that the type and the amount of the cation-containing compound and the anion-containing compound and the type and the amount of the urea resin were set as shown in Table 1 below. In the same manner as in Example 1, modified wood was obtained. Moreover, about Comparative Examples 1-3,
In Examples 1 to 5, unnecessary Na ₂ HPO ₄ was sprayed, urea resin was not sprayed, or anion-containing compound containing no guanidine salt was sprayed.

The results of impregnation rate, flame retardancy, moisture resistance and dimensional stability of the obtained modified wood are shown in Table 2.

[0038]

[Table 1]

[0039]

[Table 2]

Comparative Example 1 is an unnecessary N in Examples 1-5.
a ₂ HPO ₄ was sprayed, but Na ₂ HPO ₄
Thus, Comparative Example 1 was also excellent in flame retardancy, but Examples 1 to 5 were superior in moisture resistance. Comparative Example 2 is Example 1
Although the urea-based resin sprayed in No. 5 was not sprayed, the moisture resistance of Comparative Example 2 was further lowered than that of Comparative Example 1. This is because the insoluble compound is efficiently generated inside the wood, or by-products and unreacted substances remain fixed in the wood while being soluble, and as a result, the function of the urea resin that further improves water resistance and moisture resistance is exerted. It is shown. In Comparative Example 3, Na ₂ HPO ₄ was sprayed instead of the anion-containing compound containing the guanidine salt sprayed in Examples 1 to 5, but Comparative Example 3 also has excellent flame retardancy due to the action of Na ₂ HPO _4. However, the impregnation rate and moisture resistance are reduced. By reversing this, Examples 1 to 5 had higher impregnation ratios and had excellent flame retardancy. The reason for this is that the anion-containing compound, which is a guanidine salt, can efficiently produce an insoluble compound inside wood, reduce soluble by-products and unreacted substances, and consequently improve water resistance and moisture resistance. Because. In general, using anion-containing compounds that are guanidine salts and using urea-based resins such as melamine resins and urea resins as additives that react with by-products and unreacted products to form insoluble compounds Insoluble compounds are generated inside the wood,
Alternatively, it can be seen that the by-products and unreacted substances remain fixed in the wood while remaining soluble, and as a result, the water resistance and moisture resistance are further improved.

[0041]

According to the method for producing modified wood of the present invention, flame retardancy and dimensional stability can be maintained and moisture resistance can be improved.

[Brief description of drawings]

FIG. 1 is a schematic view of steps in a method for producing modified wood according to an embodiment of the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenji Onishi, 1048, Kadoma, Kadoma, Osaka Prefecture, Matsushita Electric Works Co., Ltd. (72) Ryusuke Honda, 1048, Kadoma, Kadoma, Osaka City, Matsushita Electric Co., Ltd.

Claims (3)

[Claims] 1. One of a cation-containing compound and an anion-containing compound, which reacts with each other on a raw material wood to be modified to form an insoluble compound, on one side of the raw material wood, and the other compound on the other side. On the surface of the
A soluble by-product that is produced at the same time as the formation of an insoluble compound by impregnation and curing, and a drug that reacts with an unreacted product to form an insoluble compound are used. A method for producing modified wood, which comprises a guanidine salt, and an additive that reacts with the by-products and unreacted materials to form an insoluble compound. 2. One of a cation-containing compound and an anion-containing compound that reacts with the raw material wood to produce an insoluble compound, and one compound of the cation-containing compound and the anion-containing compound on one side of the raw material wood and the other compound of the other raw material wood. In the process of spraying on one surface, facing the surface in which the compound is sprayed in the same direction, and curing the raw material wood in which the cation-containing compound has been sprayed and the raw material wood in which the anion-containing compound has been sprayed alternately. An additive that reacts with a by-product or an unreacted substance to form an insoluble compound is sprayed and impregnated with at least one of a cation-containing compound and an anion-containing compound to form the insoluble compound. The method for producing modified wood according to claim 1. 3. The method for producing modified wood according to claim 1, wherein a urea resin is used as the additive.