JPH06315907A - Decolor processing agent and decolor processing method for wood - Google Patents

Abstract

PURPOSE:To decolorize a wooden material by allowing safely the natural tone of a color to survive without making use of expensive and hazardous hydrogen peroxide, by a method wherein a decolor processing agent of lumber is constituted by consisting effectively of ferment and decolor processing of the lumber is performed by bringing a ferment solution into contact with the wooden material. CONSTITUTION:A decolor processing agent is constituted by allowing the same to contain ferment as an effective component. Then decolor processing of lumber is performed by bringing a ferment solution into contact with a wooden material. In other words, the decoloring processing of the lumber is performed by bringing the solution containing the ferment and a substrate of the ferment into contact with the wooden material. Then oak or the other natural lumber or a veneer, that is, a fancy veneer or plywood which are obtained by cutting those lumber are used as the mooden material of the object of decolorization. Then hydrolase such as amylase or others or oxidoreductase such as glucose oxydase or the others are used as the ferment. Hereby, the wooden material is decolorized by allowing safely the natural tone of a color to survive without making use of expensive and hazardous peroxide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for decolorizing wood materials. More specifically, enzymatic wood, especially
The present invention relates to a decolorizing method for a plate (a single plate cut with a slicer).

[0002]

2. Description of the Related Art Generally, a method of decolorizing (bleaching) wood such as wood veneer is accomplished by destroying or modifying the structure of chromophore and auxochrome in wood by applying oxidation or reduction reaction. .

Oxidative bleaching agents are roughly classified into inorganic chlorine type (calcium hypochlorite, sodium hypochlorite, sodium chlorite etc.), organic chlorine type (chlorinated isocyanurate, chloramine B etc.) and inorganic. Peroxide type (hydrogen peroxide, sodium peroxide, urea peroxide, sodium peroxide, etc.) and organic peroxide type (peracetic acid, benzoyl peroxide,
Modified methyl ethyl ketone peroxide).

The reducing bleaching agents include hydrogen compounds (sodium borohydride, etc.), nitrogen-containing compounds (hydrazine, semicarbazide, etc.), inorganic sulfur compounds (sodium hypochlorite, sodium hydrogen sulfite, sulfur dioxide, etc.), organic sulfur compounds. (Toluenesulfonic acid, methionine, etc.) and acids (oxalic acid, hypophosphorous acid, ascorbic acid, etc.) can be mentioned.

When the aqueous solution of hydrogen peroxide, which is an oxidant, is adjusted to be alkaline and the aqueous solution of sodium chlorite is adjusted to be acidic, the strength of oxidative bleaching is remarkably exhibited.

On the other hand, each aqueous solution of hydrazine hydrate as a reducing agent and Rongalit exhibits a strong reducing power when heated to about 80.degree.

For example, the bleaching method using a typical hydrogen peroxide will be described. An aqueous solution is made into an alkaline aqueous solution adjusted to pH 9.5 to 11 with an activating aid (ammonia water, sodium hydroxide, etc.). It is performed by immersing the wood-based material and heating it.

In the above-described decolorizing method using hydrogen peroxide, the hydrogen peroxide solution used as a decolorizing solution is repeatedly used, but during decolorization, hydrogen peroxide decomposes and decreases, and Since the decomposition of hydrogen peroxide in the decolorizing solution becomes remarkably high with repeated use, it was necessary to replenish the decolorizing solution with a large amount of expensive and dangerous hydrogen peroxide for regeneration.

In order to solve this problem, hemicellulase is added to remove impurities in the decolorizing solution containing hydrogen peroxide to decompose hemicellulose in the decolorizing solution,
There has been proposed a method of converting hydrogen peroxide into a substance that does not promote decomposition, preventing decomposition of hydrogen peroxide, and using the decolorizing solution efficiently and repeatedly. (JP-A-56-14850
7)

[0010]

However, hydrogen peroxide used for decolorizing wood-based materials is usually used as an aqueous solution, but its oxidizing power is strong and it reacts violently with flammable and reducing substances. Occasionally there is a risk of explosion.
Furthermore, it is highly toxic to the human body, and it is said that direct contact should be strictly avoided.

As described above, the decolorizing method for a wood-based material using hydrogen peroxide, which has been conventionally used, requires great care during work, and further requires careful measures such as strict protection. As described above, there are some problems in repeated use.

Further, hydrogen peroxide has a very strong oxidative power and acts too strongly on the wood material to eliminate even the delicate original color of the wood material. It was necessary to color it later.

[0013]

[Means for Solving the Problems] The inventors of the present invention have conducted extensive studies in view of the above problems, and made the wood material to retain its original color tone without using hydrogen peroxide at all.
The present invention has been completed for the first time by finding out that these problems can be solved by using an enzyme solution instead of hydrogen peroxide as a decolorizing agent for a wood-based material which has no danger to the human body.

That is, the present invention relates to a method for decolorizing a wood-based material, which comprises bringing the wood-based material into contact with an enzyme-containing solution.

The woody material to be decolorized according to the present invention includes various natural woods and plywood. As the natural wood, there are oak wood, teak wood, lauan wood and the like, which are also suitably used for veneers cut from these natural woods, so-called lumber. Of course, it can be applied to all other wood materials.

Any enzyme can be used as long as it exhibits a decolorizing action on the wood material. As the enzyme, hydrolases and oxidoreductases can be applied to a wide range of wood materials.

Examples of hydrolases include amylase,
Proteases, pectinases, lipases, cellulases and the like can be mentioned, and examples of the redox enzymes can include glucose oxidase and catalase.
These enzymes can be used alone or in combination. These enzymes do not have to be purified to a single form, and ordinary commercial products can be used. In addition to the enzyme, a substrate for the enzyme, such as starch or glucose, can be present together.

For example, as amylase agents, biozyme (manufactured by Amano Pharmaceuticals), krystase (manufactured by Daiwa Kasei), sumiteam (manufactured by Shin Nippon Chemical Co., Ltd.), cochrase (manufactured by Sankyo),
Spitase (manufactured by Nagase & Co., Ltd.) and the like. Examples of protease agents include protease "Amano" (manufactured by Amano Pharmaceutical Co., Ltd.),
Protin (manufactured by Daiwa Kasei), bioprase (manufactured by Nagase & Co.)
And the like, and the pectinase agent includes pectinase A.
(Manufactured by Amano Pharmaceutical Co., Ltd.) and the like. Examples of the lipase agent include lipase “Amano” (manufactured by Amano Pharmaceutical Co., Ltd.), lipase “Saiken” (manufactured by Nagase & Co., Ltd.), lipase MY (manufactured by Nagase & Co., Ltd.) and the like, and as cellulase agents. Is cellulase "Amano"
(Manufactured by Amano Pharmaceuticals), Sumiteam C (manufactured by Shin Nippon Kagaku Kogyo),
Cellulase “Onozuka” 3S (manufactured by Yakult), hemicellulase “Amano” (manufactured by Amano Pharmaceutical) and the like can be mentioned.

Examples of glucose oxidase agents include Hyderase (manufactured by Amano Pharmaceutical Co., Ltd.) and glucose oxidase (manufactured by Novo Nordisk Bioindustry). Catalase agents include catalase L "Amano".
(Manufactured by Amano Pharmaceutical Co., Ltd.), catalase “Nagase” (manufactured by Nagase & Co., Ltd.), catalase (manufactured by Novo Nordisk Bioindustry) and the like. Further, these enzymes can be used alone or in combination.

The conditions for treating the woody material with the above enzyme solution are appropriately selected depending on the enzyme activity, purity and the like.
Usually the temperature is 10-80 ° C, preferably 30-50 ° C, the pH is 3-10, preferably 6-8, the concentration is 0.01-10%, preferably 0.1-5%. The treatment time is 1 to 72 hours, preferably 10 to 40 hours.

These conditions can be changed depending on the target wood material, and can be changed while confirming the degree of decolorization and the texture of the wood material during the processing.

As a method for contacting the enzyme solution with the woody material, any method such as dipping, spraying or coating can be used.

After the above-mentioned treatment, a decolorized wood material can be obtained by washing with water and air-drying if necessary. Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto.

[0024]

【Example】

Example 1 A board (oak wood and teak wood: 20 × 20 cm each) was immersed in 0.1% of each enzyme solution and treated at 45 ° C. for 24 hours. After washing with water and air-drying, the whiteness (W) was measured with a color difference meter (Tokyo Denshi Color Ace Model TCA-I). The same treatment was carried out using purified water as a control. The results are shown in Table 1.

The enzymes used are as follows. Hyderase (glucose oxidase and catalase agent: manufactured by Amano Pharmaceuticals) Protease P (protease agent: manufactured by Amano Pharmaceuticals) Pectinase A (pectinase agent: manufactured by Amano Pharmaceuticals) Lipase AY "Amano" (lipase agent: manufactured by Amano Pharmaceuticals) Hemicellulase "Amano" (Cellulase agent: Amano Pharmaceutical Co., Ltd.) Biozyme C (amylase agent: Amano Pharmaceutical Co., Ltd.) Amylase AD (amylase agent: Amano Pharmaceutical Co., Ltd.)

[0026]

[Table 1]

As a result, the woody material was decolorized by any of the treatments, and the color of the decolorized woody material retained the original color.

Example 2 Using oak wood and teak wood different from those used in Example 1, 0.1% Biozyme C powder as an enzyme and treated at 45 ° C. for 24 hours and 48 hours were treated in the same manner as in Example 1. Then, the whiteness was measured. The results are shown in Table 2.

[0029]

[Table 2]

From Table 2, it can be seen that the degree of decolorization changes depending on the processing time.

Example 3 A board (oak material: 20 × 20 cm) was immersed in a biozyme C enzyme solution having various concentrations and treated at 45 ° C. for 24 hours. After washing with water and air-drying, a color difference meter (Tokyo Denshi Color Ace Model TCA-
The whiteness (W) was measured in I). The same treatment was carried out using purified water as a control. The results are shown in Table 3.

[Table 3]

From Table 3, it can be seen that the degree of decolorization changes depending on the enzyme concentration.

Example 4 0.06% Hyderase "Amano" prepared by adding a board (oak: 20 × 20 cm) with various concentrations of glucose and soluble starch.
It was immersed in the enzyme solution and treated at 45 ° C. for 24 hours. After washing with water and air-drying, the whiteness (W) was measured with a color difference meter. As a control, the same treatment was carried out using only the hyderase enzyme solution. The results are shown in Table 4.

[0034]

[Table 4]

It can be seen from Table 4 that the decolorizing ability is enhanced by treating the hydrolase "Amano" with the enzyme solution containing glucose or starch, as compared with the enzyme alone.

[0036]

EFFECTS OF THE INVENTION According to the present invention, it is possible to decolorize a wood-based material without using hydrogen peroxide at all, while keeping the original color of the wood-based material and without causing any danger to the human body.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Junya Hirano 1-2-7 Nishiki, Naka-ku, Nagoya-shi, Aichi Amano Pharmaceutical Co., Ltd. (72) Nobuyuki Harada 3-chome, Meinan 5-chome, Nishinari-ku, Osaka 6 Koike Cosmetic Plywood Co., Ltd. (72) Inventor Kenzo Hasegawa 2-48 Nishiyamahara, Yodogawa-ku, Osaka Sanyu Paint Co., Ltd. (72) Inventor Masayoshi Kato 2-4-10, Concentration, Kita-ku, Osaka (72) Invention Kazuo Fukasawa 2-48 Nishimiyahara, Yodogawa-ku, Osaka Sanyu Paint Co., Ltd.

Claims (3)

[Claims] 1. A decolorizing agent for wood containing an enzyme as an active ingredient. 2. A method for decolorizing wood, which comprises contacting a woody material with an enzyme solution. 3. A method for decolorizing wood, which comprises contacting a woody material with a solution containing an enzyme and a substrate for the enzyme.