JPS5842813B2 - wood treatment method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for treating wood, and in particular to a method for degreasing resin-rich wood without causing significant discoloration.

Plants that belong to the order Eyelids and Eyes, such as Karamatsu and Kaya, contain a lot of resin, and the wood obtained from them can be used as wood with good water resistance.

However, when these woods are used as craft materials, there are problems such as resin exudation, which reduces the value of the craft, and causes unevenness when painting.

In order to overcome these drawbacks, the conventional methods have mainly been to improve paints, and although there are few prior art techniques using wood treatment such as the present invention, the one closest to the present invention is the Japanese Patent Publication No. 49-1983. Publication No. 32921 and Special Publication No. 50-71
There is an invention of a wood treatment method using an aqueous solution of soda ash and an activator disclosed in Japanese Patent No. 21.

Although this invention has the effect of reducing dry cracking and falsification by degreasing the wood, the treatment causes the wood to become dark brown in color.

An object of the present invention is to provide a wood treatment method that easily and effectively degreases wood without reducing the value of the wood due to coloring.

As a result of extensive studies, the present inventors have discovered that the above object can be achieved by heating wood with an aqueous solution of a base containing nitrogen atoms and then separating the wood from the treatment liquid, leading to the present invention.

The type of wood to be treated in the present invention is not particularly limited, but for the purpose of the present invention, wood with a high resin content, for example, wood obtained from plants belonging to the order Eyelita or First order is usually used.

Examples of tree species from which wood is derived include the Pinus family,
For example, Akamatsu, Kuromatsu, Karamatsu, Ezomatsu, Toratsu, Tsuga, Tohi, fir, Himekomatsu, Goyomatsu, etc., Cypress family, for example, Koyamamatsu, Sugi, Hinoki family, for example, Kurobe. , Asunaro, Hinoki, Sarara, etc.

Also, in the order Ichiidae, for example, Ichii, Kaya (
Hangaya, Kae, Shirokaya, Tachikaya), Maki family, such as Inumaki, Inukaya family, such as Inukaya, Chosenmaki, etc.

The term base having a nitrogen atom used in the present invention means
This is in contrast to bases based on alkali metals such as caustic alkali and alkali carbonate.

Specifically, ammonia, aliphatic primary amines, aliphatic secondary amines, aliphatic tertiary amines, aliphatic quaternary ammonium compounds, amino alcohols, alicyclic amines, aromatic amines, nitrogen-containing Heterocyclic compounds, etc.

The nitrogen atom portion that provides basicity is considered to be an amine group derivative in a broad sense, including substituted ones, but in order to distinguish it from an amino group -NH2 in a narrow sense, the expression ``a base having a nitrogen atom'' was used.

These bases can be used in the form of salts formed by neutralization (including partial neutralization) with fatty acids, carbonic acids, bicarbonates, sulfurous acids, carbamic acids, amino acids or resin acids to provide the desired pH in aqueous solutions.
It can have H.

The above bases and their salts can be used alone or in mixtures.

Examples of aliphatic primary amines include menalamine, enalamine, n-propylamine, isopropylamine, bunalamizos, pentylamines, hexylamines,
Examples include ofnal amines such as 2-ethylhexylamine.

Examples of aliphatic secondary amines include diethylamine, diethylamine, diisopropylamine, ethylhexylamine, di-bunalamine, etc.; examples of aliphatic tertiary amines include trimenalamine, triethylamine, methyldienalamine, diethylhexylamine, etc. Nalbutylamine etc.

Examples of aliphatic quaternary ammonium compounds include tetramethylammonium hydroxide, tetraethylammonium hydroxide, trimethylvinylammonium hydroxide, and choline; examples of aminoalcohols include heptano, di-, and triethanolamine. , 2-amino-1-butanol, 2-(enalamino)ethanol, 2-(diethylamine)ethanol,
2-(diethylamine)ethanol, enaldiethanolamine, butyljetanolamine, and examples of alicyclic amines include cyclohexylamine, N, N
Examples of aromatic amines include aniline, toluidine, N-menalaniline, N,N dimenalaniline, and examples of nitrogen-containing heterocyclic compounds include pyridine, picolines, enalpyridine, and dimethylpyridine. , lunadines, collidines, pyrrolidine, piperidine, and morpholine.

Among the acid components when these bases are used as salts, examples of fatty acids include saturated basic acids such as formic acid, acetic acid, propionic acid, butyric acid, and caproic acid, as well as unsaturated acids such as crotonic acid, succinic acid, There are polybasic acids such as adipic acid and itaconic acid.

For example, by using the above base in the form of a salt such as diethylamine carbonate, partially neutralized salt of ethanolamine in acetic acid, or choline phosphate, it is possible to obtain a treatment solution with a lower pH than when the base itself is used. can.

However, in order to sufficiently extract the resin content from the wood, the pH of the treatment liquid needs to be 7 or higher, so the combination of base and acid can be selected using this as a criterion.

The base having a nitrogen atom is usually 0.05 to 2% (weight 70%).
shows.

(the same applies hereinafter), preferably as an aqueous solution with a concentration of 0.1 to 0.8%.

The pH of the aqueous solution is usually in the range of 7 to 12.

Excessively basic substances, such as the use of strongly basic substances at high concentrations, are undesirable from the viewpoint of preventing coloration.

Some of the base is consumed by the substances contained in the wood, and the pH of the treatment solution tends to decrease during heat treatment.
Adding a base with a nitrogen atom during the process to maintain proper pH often gives favorable results.

Unlike inorganic bases such as soda ash, the nitrogen atom-containing base used in the present invention has good permeability into wood, and usually does not require auxiliary agents such as surfactants. It is of course possible to use adjuvants in combination as required.The present invention is characterized in that a nitrogen atom-containing base is used in the form of a relatively dilute heated aqueous solution. Known techniques for processing wood by impregnating it with itself or its concentrated aqueous solution and utilizing the plasticizing effect (for example, Japanese Patent Publication No. 35123/1983)
(see Japanese Patent Publication No. 49-35402) and is completely different not only in its purpose but also in the concentration and action of the base used.

The amount of treatment liquid required for wood treatment is influenced by the amount of resin contained in the wood and the concentration of amines in the treatment liquid, and also depends on the shape of the treatment equipment, but usually the amount of treatment liquid equal to or more than the weight of the wood is used. .

It is preferable to use at least an amount of the treatment liquid that is sufficient to completely immerse the wood, and to prevent the wood from floating and coming into contact with air.

This is significant not only in ensuring sufficient contact between the treatment liquid and the wood, but also in preventing discoloration of the wood.

The processing temperature is 60 to 120℃, and the processing pressure is normal pressure, pressurized,
Although any method under reduced pressure may be used, it is usually convenient to carry out the reaction under normal pressure under boiling reflux of an aqueous solution.

In this case, by providing a cooling reflux device, even a volatile base such as ammonia can be collected and refluxed as an aqueous solution, thereby preventing it from escaping.

Low temperature immersion below 60'C, for example room temperature immersion, requires a long time for treatment.

It is possible to perform high temperature treatment at 100°C or higher using a pressure cooker, but if the temperature is too high, the coloring will be strong and the effect of the present invention will be easily impaired, so it is recommended to carry out the treatment at a temperature of about 120°C as mentioned above. preferable.

A specific example in which the present invention was implemented using conditions under pressure is shown in Example-3.

In the present invention, the aqueous base solution containing nitrogen atoms easily penetrates into the interior of the wood under heating conditions, and extracts the resin content into the treatment liquid.

And even though the treatment is carried out under conditions that exceed pH 7, it is possible to avoid significant color changes such as the dark browning that occurs when using alkali such as soda ash. be.

After heating, the resin component is easily removed from the wood together with the heat treatment liquid by removing the wood from the treatment liquid while it is heated or separating it by discharging the treatment liquid.

Although it is possible to separate the treatment liquid after cooling, there is a risk that the dispersed resin may adhere to the surface of the wood and cause contamination, so hot separation is preferable.

The wood separated from the treatment solution is piled up and dried in the usual way to produce a product.

A product with less cracking and discoloration during drying, less resin, and less coloring is obtained.

Such wood has no uneven coating due to resin, and when treated with transparent lacquer, it exhibits an excellent effect in terms of brightness, which was not possible with the prior art.

In addition, it has excellent properties for post-processing, such as fewer cracks in the fabric and fewer defects such as cracks in painted products.

Furthermore, the present invention is characterized in that it is easy to decolorize the waste liquid produced by its implementation.

In the prior art, in order to remove colored substances from the blackish brown waste liquid generated by wood processing, activated sludge treatment is first performed, as disclosed in JP-A-51-20471, and then an inorganic flocculant and a Kanaone polymer flocculant are added. needed to be used.

However, Kanone-based polymer flocculants are generally highly toxic to fish, and their use is therefore undesirable.

On the other hand, the wood treatment waste liquid obtained by the method of the present invention can be easily decolored by using an inorganic flocculant and an anionic and/or nonionic polymer flocculant, and there is no need to use a cationic one.

Reference Example 1 shows an example showing that the waste liquid produced by carrying out the present invention can be easily decolorized without using a Kanone-based flocculant.

Note that the wood curve forming method disclosed in JP-A-50-24407 has a common feature with the present invention in that it is treated with an aliphatic amine, but this method adsorbs the amine press-injected in the gas phase. This method uses a plasticizing effect, which is completely different from the present invention in which the resin component is extracted and removed by heat treatment in an aqueous base solution.

The following examples show how the present invention was actually implemented.

Example 1 Length 1,000rIL1rt1 Thickness 23mm, Width 48mm
(Larch cubes weighing approximately 6,251 kg were immersed in various treatment liquids 31, heated, and treated under boiling reflux for 150 minutes, then taken out while hot.

The results of determining the amount of eluted resin and wood coloring at this time are shown in Table 1 along with the composition and pH of the treatment solution.

Materials treated according to the above examples showed less cracking during drying and no evidence to the contrary.

Example 2 The outer skin of a Hinoki log with a diameter of approximately 10 cx and a length of 30 cIrL was removed, and this (weight approximately 24 oo, 9) was treated with treatment liquid 1*.
61 and treated under boiling reflux for 7.5 hours,
I took it out when it was hot.

The results of determining the amount of eluted resin and wood coloring at this time are shown in Table 2 along with the composition and pH of the treatment solution.

Reference Example 1 The wood processing waste liquid obtained in Examples 1 and 2 was collected in a 100-meter cylinder, and treated with aluminum sulfate and an anionic polymer flocculant (Oligo-Z, P-1000 manufactured by Tomegawa Paper Mills) or nonionic. A polymeric Miran flocculant (Kayafloc, N-200, manufactured by Nippon Kayaku ■) was added, and after inverting five times, the mixture was allowed to stand still and the separation status was observed.

The results are shown in Table 3.

Example 3 Three 30mm boards, four 20mm boards, and 9 15mm boards (each length 1200+
am) A total of approximately 45 kg (moisture content 65%) was placed in a stainless steel vertical wood processing pot (inner diameter 318 m door, body height 140 m).
0) from above, added 0.3% triethylamine aqueous solution 301, and sealed.

The wood is kept completely immersed in the treatment liquid by the action of an anti-float bar installed on the upper flanged lid.

The jacket was heated by passing 25 kg/cI/LG steam.

The internal temperature reaches 120°C in about 30 minutes, and further increases to 120°C~
It was kept at 130°C for 6 hours.

Thereafter, the heating steam was stopped, and a valve provided at the top of the processing pot was opened to gradually release the steam and the internal pressure was brought to normal pressure.

After cooling water was passed through the jacket to cool the inner temperature to 50° C., the bottom valve was opened and the processing liquid was taken out.

The top cover was removed, the board was taken out, and it was left indoors to air dry.

After about 1 month, the moisture content reached 10%, and the board was measured for warping, warping, and twisting.

For comparison, approximately 38 kg of similar larch wood (moisture content 68%)
) into a processing pot, add 0.3% soda carbonate and 0.1% anionic surfactant (Emaru 10 powder manufactured by Kako Soap Co., Ltd.)
After about 1 month, the same operation was carried out using 30A of aqueous solution.
A plate with a moisture content of 3% was obtained.

am/10 ctr for each width warp, warp, and twist
t.

rILm/100cm, mm/10 x 100
ffl was converted, and the distribution ratio of counter-evidence data was calculated, and the following results were obtained.

As is clear from the table, the use of triethylamine aqueous solution has a better yield of plates with less evidence to the contrary.

Claims (1)

[Claims] 1. A wood treatment method characterized by heating wood with a treatment aqueous solution containing a base having a nitrogen atom and then separating the wood from the treatment solution to remove the resin content.