JPS63293006A - 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]

A method for producing modified wood has been developed in which insoluble and nonflammable inorganic substances are produced in wood to impart dimensional stability, flame retardancy, rot and insect repellency, and mechanical strength.

There are various treatment methods for imparting flame retardancy to wood, and they can be categorized 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 (e) Absorption of heat due to decomposition and release of crystallized water (fl) If insoluble nonflammable inorganic substances are included in the insulated wood by the foam layer, the above (a)
In addition, depending on the type of inorganic material, (b) or d)
We can also expect effects from this mechanism.

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 mechanism of +a) to d) will be explained in detail below. (a) Even if the material is a combustible material, it can be made flame retardant by combining it with an insoluble 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 the world is as follows. That is, when wood is heated, it thermally decomposes and generates flammable gas, which ignites and burns, but 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, it has a high flame retardant effect. (C) is a mechanism in which halogen acts as a chain transfer agent in a radical oxidation reaction in a flame, thereby inhibiting the oxidation reaction and producing a flame retardant effect. Therefore, if the insoluble nonflammable inorganic substance contains a halogen, a flame retardant effect can be obtained by this mechanism. (dl is carbonate,
The mechanism is that ammonium salts and the like generate nonflammable gases such as carbon dioxide gas, sulfur dioxide gas, and hydrogen halides through thermal decomposition, and these gases dilute combustible gases and prevent combustion. Therefore, if the insoluble nonflammable inorganic substance can generate nonflammable gas such as carbonate,
This mechanism provides a flame retardant effect.

Next, we will explain how to prevent wood from rotting and insects.When fungi cause wood to rot, it is essential that mycelia 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 wood cavity does not need to be a drug (preservative) with a particular antiseptic effect, and may be anything as long as it does not provide nutrients for fungi.Insect repellent is the same as preservative. 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.

Additionally, dimensional stabilization and mechanical strengthening of wood will be discussed. If wood is swollen with water and some substance can be fixed in the wood cell walls, dimensional stabilization and mechanical strengthening effects 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,
Fixing insoluble, non-combustible minerals into wood cell walls can improve dimensional stability and mechanical strength.

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

Therefore, the present inventors prepared two aqueous solutions in which ions that can react to produce insoluble, nonflammable inorganic substances were separately dissolved.
We have developed a method to produce insoluble nonflammable inorganic substances by dissolving water-soluble inorganic substances in water, impregnating rainwater solution into wood cells in order, and causing ions to react with each other in the wood.

According to this method, it is possible to obtain modified wood that has high performance in terms of antiseptic and insect repellent properties and mechanical strength.
There was room for further improvement in terms of flame retardancy, dimensional stability, and hygroscopicity.

On the other hand, a method has already been developed for improving flame retardant properties by applying a resinous powder flame retardant composition to wood or the like (International Publication Number: WO36101457).

Since this method involves applying and filling flame-retardant resin onto wood, etc., the amount of filling and coating on the base material is small, making it impossible to significantly improve flame retardancy, and the effect of improving dimensional stability. Nor.

As a result of various studies on the resin treatment of wood as described above, the present inventors have determined that in order to improve flame retardancy and dimensional stability, it is necessary to introduce a chemical that generates resin in wood into the wood in the form of an aqueous solution. , I found out that it needs to be impregnated separately and in large quantities.

[Purpose of the invention]

This invention was made in view of the above circumstances, and has been developed to provide an improvement that has excellent antiseptic and insect repellent properties and mechanical strength, as well as highly excellent dimensional stability and flame retardancy, and also greatly improves hygroscopicity. The purpose is to provide a method for producing quality wood.

[Disclosure of the invention]

In an attempt to achieve the above objectives, the present inventors
Various researches were conducted.

As a result, instead of filling or coating the wood with resin powder or inorganic substances, substances that generate resin or insoluble inorganic substances by reaction are coexisting in the form of aqueous solutions and impregnated into the wood. The inventors have discovered that the above object can be achieved by a method of producing an inorganic substance and a resin, leading to the present invention. According to this method, the amount of resin and inorganic substances impregnated into the wood is extremely large, the resin firmly fixes the insoluble inorganic substances, and the resin intertwines with the wood fibers, resulting in flame retardancy and dimensional stability. Furthermore, since the chemicals in the wood are fixed with resin, there is no leakage of the chemicals and the moisture absorption of the wood can be greatly improved.

If the solutions that generate the resin are used separately,
Resin formation in the liquid is less likely to occur, and there is no contamination, making it possible to reuse it.Since the resin produced is made insoluble, it is less likely that the resin will seep out, and there will be no contamination of the subsequent treatment liquid. The above is not limited to the above flame retardant composition.

In summary, this invention produces and fixes insoluble inorganic substances and resin within the structure of the wood by impregnating wood separately with an aqueous solution of substances that produce insoluble resin and inorganic substances when mixed. The main points are as follows.

The present invention will be explained in detail below.

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

Examples of insoluble, nonflammable inorganic substances that are generated in wood and dispersed and fixed in the wood structure include salts such as carbonates, sulfates, silicates, phosphates, hydroxides, and borates, and two or more may coexist in the wood. The cationic portion of the salt mentioned above includes:
For example, Ca −, B a s M g % M n
s Z n % A l s S r % P b,
Examples include Cd, Ni, Na, and Si. Among these, alkali metals, alkaline earth metals, and Al are preferable, and examples of those constituting the anion portion include BO, POa, Co, Bo4, N
Examples include o1, OH% Cl5Br, F, ■, and 0. Among these, Bo3, Bo4, CO3, S0
Anions such as 4, C1, F, Br and OH are preferred. BO,,po, is the effect due to the mechanism (b) above, CO8 is the effect due to the mechanism (d) above, CI
F and Br are more preferable because they can expect the effects of the mechanisms (C) and (d) above, respectively. More preferable results can be obtained if certain restrictions due to ionic radius and the like are avoided in the combination of the cation portion and the anion portion. In addition,
One type of insoluble nonflammable inorganic substance may contain two or more types of cation moieties or anion moieties at the same time.

Examples of resins that are generated in wood and dispersed and fixed within the wood structure include urea resin, phenol resin, etc.
More than one species of resin may coexist.

The solution with which wood is impregnated to produce an insoluble resin is prepared by dividing at least two types of components that are raw materials for producing the resin. For example, two types of aqueous solutions are prepared, one of which is an aqueous solution (A) containing at least one aldehyde such as formaldehyde, acetaldehyde, and furfural, and the other is an aqueous solution containing phenol such as phenol cresol and xylenol. The aqueous solution (B) contains at least one of urea, melamine, etc., and either or both of these two aqueous solutions contain catalysts such as ammonium salts, alkali metal compounds, and alkaline earth metal compounds. The combination of agents necessary for resin synthesis, which may include at least one agent, is not limited to the above, but may be any combination that produces resin in wood through reaction.

It goes without saying that the impregnation of these agents into the wood must be carried out in such a sequence as to produce a resin in the wood. Each drug solution may be impregnated repeatedly in alternation.

If the type of resin to be produced is selected from the above-mentioned resins that have high internal flame retardancy, the resulting wood will have extremely excellent flame retardancy.

The method for producing insoluble inorganic substances and insoluble resins in wood is to first impregnate wood with an aqueous solution in which ions constituting cations for producing inorganic substances and an aqueous solution (B) for producing resin are mixed. Next, an aqueous solution containing a mixture of ions constituting anions for producing inorganic substances and an aqueous solution (A) for producing resin is impregnated into the wood to produce and fix insoluble inorganic substances and insoluble resin in the wood.

According to the above method, a large amount of insoluble inorganic substances and insoluble resins can be efficiently fixed in wood. Therefore, according to the method for producing modified wood according to the present invention, it has excellent antiseptic and insect repellent properties and mechanical strength, is highly flame retardant, has excellent dimensional stability, and has greatly improved moisture absorption. Modified wood can be obtained efficiently. Furthermore, it is possible to obtain modified wood whose wood texture is not impaired.

Next, description will be given based on Examples and Comparative Examples.

(Example 1) Three crane-thick rotary veneers made of pine, cedar, beech, and agathis were each immersed in water for 30 tons.

The water was saturated under reduced pressure of about rr. Next, the obtained saturated veneer was mixed with 2.0 mol of BaCl per 11 water and Hs
Immerse yourself in an aqueous solution (first bath) containing 2.0 moles of BOs and 5 moles of urea, and then add 1 j! of water! Hit, (NH4)
t 4.0 mol of HPO4, 6.0 mol of HlBO,+, 200 mj of commercially available 35% formaldehyde solution! The veneer was immersed in a mixed aqueous solution (second bath) to generate and fix insoluble inorganic substances and insoluble resin in the wood.Then, the veneer was washed with water and dried to obtain modified wood.

The treatment bath composition, inorganic substance and resin impregnation rate, and dimensional stability (anti-swelling ability: ASE) of the obtained modified wood were investigated.

The results are shown in Table 1.

(Examples 2 to 5, Comparative Example) A veneer treated with saturated water in the same manner as in Example 1 was modified by immersing it in the first bath and second bath shown in Table 1 in sequence. Created quality wood. The impregnation rate and dimensional stability (ASE) of the obtained modified wood are also shown in Table 1.

As a comparative example, results obtained by impregnating only conventional inorganic substances are shown.

Table 1 [Effects of the Invention] The method for producing modified wood according to the present invention involves mixing an aqueous solution of a substance that produces an insoluble inorganic substance and a resin.
By separately impregnating the wood, insoluble inorganic substances and insoluble resins are generated and fixed in the structure of the wood, so it has excellent antiseptic and insect repellent properties and mechanical strength, as well as flame retardancy and It has excellent dimensional stability and can greatly improve the moisture absorption of wood. Furthermore, the wood texture of the obtained modified wood is not impaired, and the method of the present invention does not cause contamination of the treatment solution.
It has the effect of being reusable.

Claims (2)

[Claims] (1) By separately impregnating wood with an aqueous solution of a substance that produces insoluble inorganic substances and resin when mixed, insoluble inorganic substances and insoluble resin are generated and fixed within the structure of the wood. Characteristic modified wood manufacturing method. (2) A substance contained in an aqueous solution of a substance that produces an insoluble inorganic substance and a resin when mixed, and inorganic ions as one of the substances that produce the insoluble inorganic substance,
It is at least one of the group consisting of alkali metals, alkaline earth metals, and Al cations, and the organic substance that forms the resin is at least one of phenols, urea, and melamine, and by mixing it, it becomes insoluble. The other substance that produces inorganic substances and resin, the inorganic ions that produce insoluble inorganic substances, are BO_3, PO_
4. A patent characterized in that it is at least one member of the group consisting of anions such as CO_3, SO_4, Cl, F, Br, OH, etc., and the substance that generates the resin is at least one member of aldehydes. A method for producing modified wood according to claim 1.