JPS6351105A - Manufacture of improved wood - Google Patents

Abstract

(57) [Abstract] 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 wood is impregnated with insoluble and noncombustible inorganic substances to obtain modified wood that has flame retardancy, antiseptic/insect repellent properties, and dimensional stability.

Next, flame retardant wood will be explained.

There are various methods for treating wood to make it flame retardant. 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 (dl
Generation of nonflammable gas (e) Absorption of heat due to decomposition and release of crystallized water (f) If insoluble nonflammable inorganic substances are included in the insulation wood using the foam layer, the above (a)
In addition, depending on the type of inorganic material, (bl, (C)) effects due to other mechanisms can also be expected.In addition, insoluble and nonflammable inorganic materials are less likely to be dissolved out of wood, so there is less risk of their effectiveness diminishing ( The mechanisms of a), (bl and (C)) will be explained in detail below. Even if the inorganic material coating in (a) is a flammable material, it can be composited with a non-flammable inorganic material at an appropriate blending ratio. For example, conventional wood cement boards are made by mixing combustible wood with non-combustible cement at a weight ratio of approximately 3:1 (1:1). It is formed into a plate shape and is recognized as a quasi-noncombustible material by JIS. (The carbonization of BL is promoted by the following mechanism. When wood is heated, it thermally decomposes and generates flammable gas. However, this causes flaming and combustion.
The presence of phosphoric acid or boric acid promotes the thermal decomposition or carbonization of 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. (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, when the insoluble nonflammable inorganic substance contains halogen, it has a high flame retardant effect.

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 wood cavity does not need to be a drug with a particular preservative effect (it can be anything as long as it does not provide nutrients for fungi. Insect repellent is the same as preservative. Therefore, insoluble and noncombustible If a natural inorganic substance is included in the inner cavity of wood, the antiseptic and insect repellent properties of the wood can be improved.

Furthermore, dimensional stabilization of wood will be explained.

If wood can be allowed to swell 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 soluble in water can also be used as fixing substances. Therefore, dimensional stability can be improved by fixing insoluble, nonflammable inorganic substances in the wood cell walls.

However, it has been difficult to obtain modified wood with sufficiently satisfactory dimensional stability using the method of incorporating insoluble, nonflammable inorganic substances into wood.

On the other hand, in order to improve properties such as dimensional stability of wood, resin is impregnated into wood and hardened. Various resins are used, but although they all improve the strength and hardness of wood, even when used in large quantities, it is difficult to suppress dimensional changes due to changes in wood moisture content. It was difficult to say that there was a significant effect on

The reason for this is thought to be that since a component having a molecular weight higher than that of a so-called oligomer is used as the resin to be impregnated into the wood, the resin hardly penetrates into the amorphous part of the cellulose in the wood. Furthermore, even if resin is included in wood, flame retardancy cannot be expected much.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and provides a method for producing modified wood that has excellent flame retardancy, antiseptic and insect repellent properties, as well as extremely excellent dimensional stability. The purpose is to

[Disclosure of the invention]

In order to achieve the above objectives, the inventors developed an insoluble non-combustible inorganic material that is highly effective in flame retardant, antiseptic and insect repellent properties, and a resin that has a relatively high dimensional stabilizing effect compared to insoluble non-combustible inorganic materials. We decided to combine them and fix them in the wood, and we conducted repeated research on a resin that has a better dimensional stabilizing effect than conventional resins. If wood is impregnated with a reactive monomer that has a high affinity for cellulose in wood and then cured, modified wood with extremely excellent dimensional stability can be obtained even with a small amount of resin impregnated. I came to the conclusion that it was possible, and conducted further research. As a result, it was discovered that at least one of methylolated phenol, methylolated melamine, and methylolated urea may be used as the reactive monomer, and the present invention has now been completed.

Therefore, this invention impregnates wood with a treatment liquid containing at least 2% by weight of at least one selected from the group consisting of methylolated phenol, methylolated melamine, and methylolated urea and a hardening agent. A step of curing the wood with a treatment solution containing 5% or more by weight of at least one selected from the group consisting of magnesium, calcium, barium and aluminum ions, and a step B of impregnating the wood with a treatment liquid containing 5% or more by weight of at least one selected from the group consisting of magnesium, calcium, barium and aluminum ions, and phosphoric acid, Boric acid.

The gist of the method is a method for producing modified wood, which includes Step C, in which wood is impregnated with a treatment liquid containing at least 5% by weight of at least one selected from the group consisting of carbonate and sulfate ions.

The present invention will be explained in detail below.

As mentioned above, in the method for producing modified wood according to the present invention,
In step A, a treatment liquid A containing at least one selected from the group consisting of methylolated phenol, methylolated melamine, and methylolated urea is used. Methylolated phenol, methylolated melamine, and methylolated urea all have a high affinity for cellulose. Therefore, it easily penetrates into the wood and even the amorphous parts of cellulose. These substances need to be contained in the treatment liquid in a weight ratio of 2% or more. This is because if it is less than this, no effect will be obtained. It is also necessary to contain an appropriate amount of a curing agent in the processing solution.

As a curing agent, for example, methylolated phenol,
Regardless of whether methylolated melamine or methylolated urea is used, carboxylic acid esters, acid anhydrides, organic halides, hydrochlorides of amines, ammonium salts, and urea derivatives.

Methylolated phenol that can use a urea adduct or the like can be produced, for example, as follows. As a raw material, the molar ratio of phenol is 1.0. Formaldehyde 2°-4.0° and sodium hydroxide 0.5-1.5° are used. The reaction temperature was 0 to 40°C in all cases, indicating low-temperature synthesis. First, sodium hydroxide is dissolved in formaldehyde while cooling. Ammonia, potassium hydroxide, and calcium hydroxide can also be used instead of sodium hydroxide.

After the sodium hydroxide is completely dissolved, mix and dissolve the phenol while cooling. The reaction mixture is stirred for 6 to 48 hours and then neutralized with hydrochloric acid. Sulfuric acid, phosphoric acid, boric acid, nitric acid, etc. can also be used instead of hydrochloric acid.

For example, methylolated melamine can be used as a raw material in a molar ratio of melamine 1.0. Formaldehyde 2.0-4
．． 0 and sodium hydroxide from 0.5 to 1.5, and by using melamine instead of phenol in the production example of methylolated phenol.

For example, methylolated urea can be used as a raw material in a molar ratio of urea of 1.0. It can be produced by using formaldehyde of 2.0 to 4.5 and sodium hydroxide of 0.5 to 1.5, and using urea instead of phenol in the production example of methylolated phenol.

The treatment liquid A used in step A can be prepared by diluting the product obtained by the reaction as described above with water or an organic solvent as appropriate, and further adding a curing agent.

In step B, using treatment liquid B containing at least 5% by weight of at least one selected from the group consisting of magnesium, calcium, barium, and aluminum ions,
In the process, 5% by weight of at least one selected from the group consisting of phosphoric acid, boric acid, carbonate, and sulfate ions is added.
Each of the processing liquids C containing the above is used. Image processing solutions B and C are used to separately impregnate wood with anions and cations as solutions such as aqueous solutions, and produce water-insoluble, nonflammable inorganic substances (inorganic salts) in the wood.

In the method for producing modified wood according to the present invention, for example, treatment liquid A is impregnated into the wood, and then a step A is performed in which the resin is hardened by heating etc. to fix the resin in the wood, and then treatment liquid B is applied. Step B is performed by impregnating the wood, and step C is further impregnated with treatment liquid C to fix the insoluble and nonflammable inorganic material in the wood. Curing of treatment liquid A by heating is 80
It is preferable to carry out the reaction at a temperature of ℃ or higher. Impregnation with the treatment liquid may be carried out by applying the treatment liquid to the surface of the wood or immersing the wood in the treatment liquid. When immersing wood in a treatment liquid, impregnation with the treatment liquid can also be accelerated by applying reduced pressure or increased pressure.

The modified wood thus obtained contains insoluble, non-combustible inorganic substances, so it has excellent flame retardancy and antiseptic and insect repellent properties.In addition, the wood contains reactive monomers that have a high affinity for the cellulose in the wood. Since the resin is impregnated and cured, even a small amount of resin impregnated has excellent dimensional stability.

The order in which each step is performed is not limited to the above A-B-C. For example, A-C-B.

It may be performed in either order: B-C→A or C→B→A. Further, at least one of the treatment liquid B of the B step and the treatment liquid C of the C step contains at least 2% by weight of at least one selected from the group consisting of methylolated phenol, methylolated melamine, and methylolated urea. The process may be performed in the order of B → C, and the A process may be performed in parallel, or the process may be performed in the order of C → B, and the process may be performed in parallel. Then, step A may be performed. In short, the order is not particularly limited as long as the insoluble, nonflammable inorganic substance and resin can be fixed in the wood.

Next, examples will be described.

(Example) First, methylolated phenol was used under the following conditions.

[Blending conditions]

Phenol 1 mole Formaldehyde 3 moles Sodium hydroxide 1 mole Hydrochloric acid 1 mole The composition of the product was as follows.

(Produced methylolated phenol) 0-monomethylolated phenol 12.33 mol% p-monomethylolated phenol 19.11 mol% o, p-dimethylolated phenol 14, 59 mol% Trimethylolated phenol 21.92 mol% 2i 17.08 mol% or higher condensate 17.08 mol% Unreacted phenol 14.97 mol% The methylolated phenol produced as described above was diluted twice with water, and 100 parts by weight of this diluted product was added as a curing agent. 1 part by weight of 20% ammonium chloride (NH, CI) solution was mixed to prepare treatment liquid A (processing resin, methylolated resol treatment liquid).

In addition, as a treated inorganic aqueous solution, BaC
Processing solution B in which 2.2 mol of 1z was dissolved, (N
H4) 8.0 mol of z HP O4 and H3BO3
First, using the treatment 't&C in which 6.0 mol of
A beech veneer with a thickness of 3 mm was subjected to water saturation treatment to a moisture content of 200% or more. Next, the veneer was immersed in treatment liquid B for 8 hours at 60°C, and the veneer was immersed in treatment liquid C for 8 hours at 60°C.
It was dried with hot air at 105°C. After that, the veneer was impregnated with treatment solution A under reduced pressure, and dried and cured at 120'C for 1 hour.
Obtained modified wood.

The obtained modified wood contained 52 insoluble and nonflammable inorganic substances (inorganic salt) and 13 resin per 100 weight of the wood. In addition to being excellent in flame retardancy, antiseptic and insect repellent properties, it also had excellent dimensional stability.

〔Effect of the invention〕

The method for producing modified wood according to the present invention includes a treatment containing at least 2% by weight of one selected from the group consisting of methylolated phenol, methylolated melamine, and methylolated urea, and a hardening agent. A step of impregnating the wood with a liquid and hardening it, a treatment liquid with a weight ratio of 5'36 to 18% of at least 1 part selected from the group consisting of magnesium, calcium, barium and aluminum ions. Step B: impregnating the wood with a treatment solution containing at least 5% by weight of at least one selected from the group consisting of phosphoric acid, boric acid, carbonate, and sulfate ions. process, so it is flame retardant, preservative,
It is possible to obtain a product that has excellent insect repellency and extremely excellent dimensional stability.

Claims (4)

[Claims] (1) A treatment solution containing at least 2% by weight of at least one selected from the group consisting of methylolated phenol, methylolated melamine, and methylolated urea and a hardening agent is impregnated into wood and hardened. Step A, Step B in which wood is impregnated with a treatment solution containing at least 5% by weight of at least one selected from the group consisting of magnesium, calcium, barium and aluminum ions, and phosphoric acid, boric acid, 5% by weight of at least one selected from the group consisting of carbonate and sulfate ions
A method for producing modified wood, including step C of impregnating wood with a treatment solution containing the above. (2) Each process is A→B→C, A→C→B, B→C→A
, C→B→A, the method for producing modified wood according to claim 1. (3) At least one of the treatment liquid of step B and the treatment liquid of step C contains at least 2% by weight of at least one selected from the group consisting of methylolated phenol, methylolated melamine, and methylolated urea. 2. The method for producing modified wood according to claim 1, wherein the steps are carried out in the order of B→C, and the step A is carried out in parallel. (4) At least one of the treatment liquid of step B and the treatment liquid of step C contains at least 2% by weight of at least one selected from the group consisting of methylolated phenol, methylolated melamine, and methylolated urea. 2. The method for producing modified wood according to claim 1, wherein the steps are carried out in the order of C→B, and the step A is carried out in parallel.