JPS63267502A - Manufacture of improved wood - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for producing modified wood used as building materials and the like.

[Background technology]

Regarding the flame retardation of wood, a method for producing modified wood has been developed in which insoluble and noncombustible inorganic substances are generated in wood to obtain modified wood that has flame retardancy, antiseptic/insect repellent properties, and dimensional stability. Explain.

There are various treatment methods for imparting flame retardancy to wood. When classified based on the mechanism of flame retardancy,
It can be divided as follows.

(al Coating with inorganic material (b) Promotion of carbonization (C) Inhibition of chain reaction in flaming combustion (d)
Generation of nonflammable gas (el) Heat absorption due to decomposition and release of crystallized water (f) If an insoluble nonflammable inorganic substance is included in the insulation wood using the foam layer, the above (a)
In addition to this, depending on the type of inorganic material, effects due to mechanisms such as ``(载)'' can also be expected. Furthermore, insoluble, nonflammable inorganic substances are less likely to be dissolved out of the wood, so there is less risk of their effectiveness being diminished.

The mechanisms of (a) and (a) will be explained in detail below. The inorganic coating (a) means that even if the material is flammable, it can be made flame retardant by combining it with a nonflammable inorganic material in an appropriate mixing ratio. For example, the conventionally known wood chip cement board is made by mixing combustible wood with noncombustible cement at a weight ratio of approximately 1:1 and forming it into a board shape, which is recognized as a quasi-noncombustible material by JIS. It is being The mechanism behind the promotion of carbonization in mountains is as follows. When wood is heated, it thermally decomposes and generates flammable gas, which ignites and burns, and the presence of phosphoric acid or boric acid promotes the thermal decomposition, or carbonization, of the wood. The carbonized layer thus formed acts as a heat insulating layer and produces a flame retardant effect.

Therefore, when the insoluble nonflammable inorganic substance contains a phosphoric acid component or a boric acid component, the flame retardant effect becomes high.

Next, we will explain how to make wood rot-proof and insect-proof. When fungi cause wood to rot, it is essential that hyphae first invade the inner cavity of the wood. However, if foreign matter is present in the internal cavity of the wood, mycelium cannot enter, and as a result, the wood becomes less susceptible to decay. The foreign matter in the internal cavity of the wood does not have to be a particularly antiseptic agent (preservative), and may be anything as long as it does not serve as nutrients for fungi. The same applies to insect repellent as preservative. However, foreign substances are good if they have a medicinal effect; for example, it is preferable that they be poorly digestible or indigestible to insects, or that have a repellent effect. Therefore, if an insoluble, noncombustible inorganic substance is included in the inner cavity of wood, the antiseptic and insect repellent properties of wood can be improved.

Furthermore, dimensional stabilization of wood will be explained.

If wood can be swollen with water and some substance can be fixed in the wood cell walls, a dimensional stabilizing effect can be obtained due to the bulk effect. Inorganic substances that are difficult to dissolve in water can also be used as immobilizing substances. Therefore, dimensional stability can be improved by fixing insoluble, non-combustible inorganic substances into wood cell walls.

However, in general, even if an insoluble, nonflammable inorganic substance is directly dispersed in water and a treatment liquid made of this dispersion is attempted to penetrate into wood, almost only water will penetrate into the wood. This is due to the following reasons. In other words, the narrowest part of the path that the treatment liquid must pass when penetrating into the wood is the pit membrane run, and the pore diameter here is approximately 0.1 μm, whereas the dispersed insoluble and nonflammable This is because inorganic particles are usually much larger than 0.1 μm.

Therefore, after impregnating wood with one of the two types of water-soluble inorganic aqueous solutions that produce insoluble non-flammable inorganic substances by mixing, the insoluble non-flammable inorganic substances are dispersed and fixed within the wood tissue by impregnating the other with this as well. This is being done (Japanese Patent Application No. 6O-089423). For example, two aqueous solutions separately containing ions that can react to form an insoluble, nonflammable inorganic substance are prepared by dissolving the water-soluble inorganic substance in water, and wood is sequentially immersed in the rainwater solution. This is a manufacturing method in which ions react with each other in wood to produce insoluble, nonflammable inorganic substances.

A specific example of this manufacturing method will be explained in detail below. First, wood such as a veneer is subjected to a water saturation treatment. An aqueous solution containing a water-soluble inorganic substance A''B- is prepared as a first treatment bath, and an aqueous solution containing a water-soluble inorganic substance X''Y- is prepared as a second treatment bath. Here, it is assumed that when the rainwater solution is mixed, the cation A+ reacts with the anion Y" to obtain an insoluble, nonflammable inorganic substance AY. Water-saturated wood is immersed in the first bath. At this time, the ion A.
, B- penetrate into the wood by diffusion. Next, when the wood is immersed in the second bath, ions X" and Y- enter into the wood, ions A° and Y- react, and the insoluble, nonflammable inorganic substance AY is fixed in the wood structure. The immersion time for the two baths is set so that the reaction is completed, that is, the cation A'' in the first treatment liquid is almost completely reacted. Of the ions A'' and B-, almost all of the cation A+ remains in the wood as an insoluble, nonflammable inorganic substance. The anion B- remains in the wood as a soluble by-product X''B-, and the rest diffuses into the second bath. - has also invaded through diffusion and is now present. After immersing in the second bath, when the wood is dried as it is, unreacted substances
0Y- will exist. X” B-, X” Y-
Since wood is soluble and absorbs a large amount of water and moisture, the water and moisture absorption of the wood itself becomes extremely high.Also, depending on the type of by-products and unreacted substances (inorganic components), it exhibits deliquescent properties. Usually the wood surface becomes sweaty. Therefore, the wood is left in running water to undergo leaching treatment to remove soluble components, and then the wood is dried. The leaching treatment solution is
It is disposed of as waste liquid.

The modified wood thus obtained has excellent flame retardancy, antiseptic/insect repellent properties, and dimensional stability because it contains an insoluble, noncombustible inorganic substance inside. Moreover, the insoluble, nonflammable inorganic material has high water resistance since there is no fear of it falling off due to water, and the above-mentioned performance can be maintained over a long period of time.

The above-mentioned method for producing modified wood requires simple equipment and equipment.However, the amount of soluble components contained in the waste liquid is large, and it is possible to efficiently convert the chemicals used as water-soluble inorganic substances into insoluble non-flammable inorganic substances. The problem was that I couldn't do it.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for producing modified wood that can efficiently convert chemicals used to produce insoluble nonflammable inorganic substances into insoluble nonflammable inorganic substances. It is said that

[Disclosure of the invention]

The inventors have conducted repeated research in an attempt to achieve the above objectives by reducing the amount of soluble components contained in the waste liquid. As a result, they decided to carry out curing before the completion of the production reaction of the insoluble nonflammable inorganic substance, and discovered that it is sufficient to complete the production reaction by this curing, and have now completed this invention.

Therefore, this invention impregnates wood with one of the combinations of a cation-containing treatment liquid and an anion-containing treatment liquid that produce an insoluble nonflammable inorganic substance when mixed, and then impregnates the wood with the other. A method for producing modified wood that allows insoluble nonflammable inorganic substances to be fixed in the tissue, characterized by curing before the completion of the production reaction of insoluble nonflammable inorganic substances, thereby completing the production reaction. Its gist is a method for producing modified wood.

The present invention will be explained in detail below.

Examples of the wood used in the present invention include raw wood logs, sawn timber products, sliced veneer plywood, etc., and the type thereof is not particularly limited. It is preferable to saturate the wood with water beforehand.

The production method of the present invention uses a combination of a cation-containing treatment liquid and an anion-containing treatment liquid that, when mixed, produce an insoluble, nonflammable inorganic substance. Cation-containing treatment liquids include Mg, At, and Ca.

A material containing one or more of cations such as Zn or Ba cations is used.

Anion-containing treatment liquids include CO3, SO4゜PO4
, one of the anions such as BO3 or OH anion
A species or one containing two or more species is used. As the anion-containing treatment liquid, it is preferable to use one containing PO4 and BOzOH anions. This is because the effect due to the mechanism of (bl) can be obtained.The cation-containing treatment liquid contains a water-soluble inorganic substance containing any one of cations such as Mg, AI, (:a, 7.n or Ba cations). It can be obtained by dissolving it in water.The anion-containing treatment liquid is, for example, CO2, S
It can be obtained by dissolving in water a water-soluble inorganic substance containing any one of anions such as O4, PO4, BO3, or OH anion. Dissolved in water, Mg, A
Examples of inorganic substances that generate t, Ca, Zn or Ba cations include MgC1t l MgBrz
l Mg5On jHz O, Mg (NO3)z
・6Hz O,A IC43,AIBr= ,Alt
(SOa)s, AI (No 3)s
・9H! O+ Ca Cl z + Ca
B r! .

Ca (N Os ) t , Z n C1t + B
aCl z ・2H2O,Ba13r,,Ba
(NO3)z etc. Dissolved in water, CO+,
SO4, PO4.

Examples of inorganic substances that generate BO or OH anions include Na! C03, (N Ha )z
COs, H! SO4, Nag SO4, CNHa
)z SO4, H3PO4, Nag HPOn +
(NH4)z HPO4* H2BO3, NaBOz
Examples include INH, BO, etc.

The wood is treated as follows. First, the wood is sequentially immersed in a cation-containing treatment liquid and an anion-containing treatment liquid. The immersion may be performed in either the cation-containing treatment liquid or the anion-containing treatment liquid first. Next, the immersion is stopped while the reaction between the anions and cations is still incomplete, that is, before all of the cations (or anions) that produce insoluble and nonflammable inorganic substances in the initially immersed treatment solution have finished reacting. Curing is performed under certain conditions.

The curing conditions, ie, temperature, humidity, 9 hours, etc., are determined depending on the type of wood, the type of cation-containing treatment liquid or anion-containing treatment liquid, etc. This curing completes the reaction between the cations (or anions) of the treatment solution soaked earlier that remain unreacted in the wood and the anions (or cations) of the treatment solution soaked later, resulting in the formation of insoluble and nonflammable inorganic substances. Complete generation. Next, leaching treatment is performed to remove water-soluble components, followed by drying. This results in modified wood.

Insoluble, non-flammable inorganic substances that are generated by the above-mentioned cation-containing treatment liquid and anion-containing treatment liquid and fixed in the wood include cases where the cation-containing treatment liquid and the anion-containing treatment liquid contain the above-mentioned cations and anions. For example, magnesium phosphate, calcium phosphate, barium phosphate, aluminum phosphate, magnesium borate.

Examples include magnesium carbonate, calcium carbonate, zinc phosphate, barium carbonate, calcium sulfate, barium sulfate, etc.

As described above, in the method for producing modified wood according to the present invention, curing is performed before the reaction for producing insoluble noncombustible inorganic substances is completed, and this curing allows the production reaction for insoluble noncombustible inorganic substances to be completed. For this reason, in the wood, the amount of ions that generate insoluble nonflammable inorganic substances contained in the treatment liquid impregnated later is greater than the amount of ions that generate insoluble nonflammable inorganic substances contained in the treatment liquid that was impregnated first. Because there is no significant excess, only a small amount of the ions in the treatment solution impregnated later remain unreacted and removed by the leaching process. can be efficiently converted into insoluble, non-flammable inorganic substances, reducing manufacturing costs.Furthermore, according to research conducted by the inventors, by selecting curing conditions, it is possible to shorten the reaction time for producing insoluble, non-flammable inorganic substances. It was also found that the effect of making it possible to

Note that the method for impregnating wood with the cation-containing treatment liquid and the anion-containing treatment liquid is not limited to immersion.

Next, examples and comparative examples will be explained (Example 1) Each of 21 thick rotary veneers made of pine, cedar, and beech wood was
Each sample was immersed in water under a reduced pressure of 20 to 30 smHg and left for 24 hours to become saturated with water. Next, the obtained saturated veneer was treated with a 50”C BaCl1g2H20 solution (2m
o 1/C pH 5-6) for 4 hours, and then immersed in a 50°C Na 2 HP Oa solution (4 mol
/L pH 6-7) for 4 hours. After the veneer was taken out from the second bath, it was wrapped to prevent it from drying and cured in a constant temperature incubator at 50°C for 20 hours. Thereafter, the veneer was subjected to leaching treatment to remove water-soluble components and dried to obtain modified wood.

The inorganic impregnation rate (weight increase rate) of the modified wood after the leaching treatment and the amount of poa'' remaining in the veneer (water bottle dissolved content) before the leaching treatment were investigated. The results are shown in Table 1.

Table 1 (Comparative Example 1) As shown in Table 1, the same as Example 1 except that the first bath treatment time was 24 hours, the second bath treatment time was 24 hours, and no curing was performed. Get modified wood. this is,
The manufacturing method is the same as before.

(Comparative Example 2) As shown in Table 1, except for no curing,
Modified wood was obtained in the same manner as in Example 1.

Regarding Comparative Examples 1 and 2, the inorganic impregnation rate (weight increase rate) of the modified wood after the leaching treatment and the residual PO4'I (water bottle dissolved content) in the veneer before the leaching treatment were investigated. The results are shown in Table 1.

From Table 1, as in Comparative Example 2, the processing time is as shown in Comparative Example 1.
If the length is simply shortened compared to the conventional production method and no curing is performed, the reaction for producing insoluble and nonflammable inorganic substances will be incomplete, resulting in a low inorganic impregnation rate of the resulting modified wood, and as in Example 1. If curing is performed in addition, even if the treatment time is short, it is possible to obtain modified wood with an inorganic impregnation rate similar to that of Comparative Example 1, and moreover, compared to Comparative Example 1, NazHPOa lost in the leaching treatment can be obtained. It can be seen that the amount of

According to research conducted by the inventors, the method for producing modified wood according to the present invention makes it possible to save approximately 10% of chemicals per batch, although this varies depending on the bath ratio of the treatment. I understand. In addition, the modified wood obtained in Example 1 also had flame retardancy, similar to that obtained in Comparative Example 1.
It had excellent antiseptic and insect repellent properties and dimensional stability.

(Example 2) In place of the BaC1g 28z O solution in the first bath,
Modified wood was produced in the same manner as in Example 1, except that aCl2 solution (3 mol/L, pH 67) was used. The inorganic impregnation rate of this modified wood is 40 to 50%,
This is the first bath BaC1!・2H! Instead of O solution, 1g CaC solution (3mo 1/j!, pH 6-7)
I started using .

In other respects, the inorganic impregnation rate was comparable to that of the modified wood produced in the same manner as Comparative Example 1. Also, in this example, the amount of N az HP O4 lost in the leaching process was small;
The resulting modified wood has excellent flame retardant properties.

It had antiseptic and insect repellent properties and dimensional stability.

(Example 3) In place of the Nag HPO solution in the second bath, Na25O,
Modified wood was produced in the same manner as in Example 1, except that a solution (3 mol/l, pH 6-7) was used. The inorganic impregnation rate of this modified wood is 35-40%, and this is because Nag S
The inorganic impregnation rate was similar to that of the modified wood prepared in the same manner as Comparative Example 1, except that O, solution (3 mo 1/l, pH 6-7) was used. The amount of Na z S Oa lost during the leaching treatment was small, and the obtained modified wood had excellent flame retardancy, antiseptic/insect repellent properties, and dimensional stability.

(Example 4) Modified wood was produced in the same manner as in Example 1, except that the curing temperature was 70°C and the curing time was varied. As a result, even if the curing time is shortened to 10 hours, Example 1
It was found that a product with an inorganic impregnation rate (4 to 45%) comparable to the above can be obtained.

Even when the curing time is 10 hours, the amount of Na z HP 04 lost during the leaching process is small, and the resulting modified wood has excellent flame retardancy, antiseptic and insect repellent properties, and dimensional stability. Was.

(Example 5) Modified wood was produced in the same manner as in Example 1, except that the curing temperature was 20 to 30°C (room temperature) and the curing time was varied. This revealed that if the curing time was set to 5 days, an inorganic impregnation rate (4 to 45%) comparable to that of Example 1 could be obtained. Additionally, this means that as long as there is a place to store the wood that has been impregnated, it is possible to produce modified wood without any hindrance, even without a curing device. It has been found that it is possible to reduce manufacturing costs without using it. Furthermore, when the curing time was set to 5 days, the amount of NatHPO4 lost in the leaching treatment was small, and the obtained modified wood had excellent flame retardancy, antiseptic and insect repellent properties, and dimensional stability. .

〔Effect of the invention〕

The method for producing modified wood according to the present invention involves impregnating wood with one of a combination of a cation-containing treatment liquid and an anion-containing treatment liquid that produce insoluble, nonflammable inorganic substances by mixing, and then impregnating the wood with the other. A method for producing modified wood in which insoluble nonflammable inorganic substances are fixed in the wood structure by curing the insoluble nonflammable inorganic substances before completion of the production reaction, thereby completing the production reaction. Therefore, the chemicals used to produce insoluble, nonflammable inorganic substances can be used efficiently (insoluble, nonflammable inorganic substances).

Claims (3)

[Claims] (1) After impregnating wood with one of the combinations of a cation-containing treatment liquid and an anion-containing treatment liquid that produce insoluble nonflammable inorganic substances by mixing, the other is impregnated into the wood. A method for producing modified wood that fixes insoluble and nonflammable inorganic substances, the method comprising:
1. A method for producing modified wood, which comprises curing before the completion of the production reaction of insoluble and noncombustible inorganic substances, thereby completing the production reaction. (2) The cation-containing treatment liquid contains Mg, Al, Ca, Zn.
and Ba cations, and the anion-containing treatment liquid contains CO_3, S
The method for producing modified wood according to claim 1, which contains at least one selected from the group consisting of O_4, PO_4, BO_3 and OH anions. (3) The method for producing modified wood according to claim 1 or 2, wherein the wood is impregnated with two types of treatment liquids by dipping.