JPS58148720A - Method of decoloring woody material - 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 The present invention provides a method for decolorizing wood materials that can efficiently decolorize sliced wood, wood, and the like.

Conventionally, decolorizing wood materials such as sliced veneers and wood was done by immersing the wood in an aqueous solution mixed with a decolorizing agent. Because the agent penetrates slowly into the wood, only the surface of the wood is bleached, and it takes a long time and darkness to completely bleach the wood, reducing productivity. There was a problem with the decline.

The present invention has been made in view of the above points, and an object of the present invention is to provide a method for decolorizing wood materials that can decolorize wood in a short time.

The present invention will be described in detail below. All wood materials such as 〇-tally or Q sliced veneer or thick wood can be used, and this wood oil material is immediately swollen with a solvent having a higher swelling ability than water. As a solvent with a large swelling ability, dimethyl sulfate, dimethyl formamide, etc. can be used, and the solvent of kneading can be used with water or alumina.
- It is dissolved in Rue 4 and the wooden hammer is immersed in this solution. Next, the swollen wood material is decolorized with an aqueous solution of a decolorizing agent such as sodium hypochlorite or hydrogen peroxide.

If decolorization treatment is desired, the wood material may be immersed in an aqueous solution of the decolorant, or the surface of the wood material may be entirely coated with the aqueous solution of the decolorizer. By doing so, the decolorizing agent easily penetrates into the interior of the swollen wood material. Next, the wooden material is irradiated with microwaves to promote decolorization. Microphone 0 wave irradiation is carried out while the wood N material is immersed in a decolorizing agent water bath solution.
Alternatively, it can be carried out with the wood taken out from the bleaching agent water bath solution in air, or in the case where the whole skin is irradiated in the air, the drying of the wood due to the heat generated during irradiation should be avoided.
It is preferable that the atmosphere during microwave irradiation is close to saturated vapor pressure.

Therefore, the wood material is swollen treated with a solvent that has a greater swelling effect than the wood material ffi 7. After that, the decolorization treatment is performed with a decolorization agent, so that the decolorization agent easily penetrates into the interior of the essential material. Efficient decolorization is achieved by irradiating the whole microwave with microwaves. In the example described in (g), the swelling treatment and the decolorization treatment were performed separately, but
lf, it doesn't work even if you do both the moisture treatment and decolorization treatment at the same time. That is, in a decolorizing aqueous solution (with a large swelling capacity), the entire surface of the solvent is mixed 1, the woodwind material is immersed in the mixed solution, or the mixed solution is applied to the wood material, and then micro-coated. Wave irradiation may also be used.In this way, decolorization can be accomplished in a shorter time.

In this case, the wood material can be dyed efficiently.11 In other words, the wood material is swollen and dyed (-7, followed by microwave treatment). By irradiating the entire wood material, the dye penetrates into the circular part of the wood material easily [7. Dyeing can be done in a short time.Hereinafter, we will explain the dyeing method of wood paulownia in a comprehensive manner. do.

<Specific Example 1> A 1.0% thick Shina rotary veneer was immersed in a 50% methanol solution of Nidimethylsulfo+cyto. 40°C
7. Then, it was immersed in a 0.5% aqueous solution of acidic dye and dyed for 10 minutes. After that, take it out from the veneer and spray live steam on the surface of the veneer while applying frequency (l)
A dyed veneer was obtained by irradiating it with a microwave at 2450 MHz and an output of 2.4 KW for 2 minutes. The dyed veneer can be dyed up to ΔE of 89 between the inside and surface of the Ll plate.

<Specific Example 2> A 0.6 fin thick Sina 0-Tally veneer was immersed in a Tco mixture containing 20% dimethylformamide, 1.0% dye, and 79% water, and heated at 60°C. Swelling and staining were carried out for 20 minutes. After that, the skewer was irradiated with microwaves with a temporary frequency of 2450 M) fz and an output of 2.5 KW for 3 minutes to obtain one stained veneer.

The obtained fco-dyed veneer can be dyed when the internal and surface △E is 7.0 years old.

As described above, according to the present invention, the essential material is swollen treated with a lubricating agent that has a larger swelling effect than water and decolorized with a decolorizing agent,
Since the microwave 0 wave is irradiated onto the wood material, the bleaching agent penetrates into the interior of the wood material, and after that, the bleaching reaction is accelerated by the micro e, and the wood material is bleached in a short time. This will improve your productivity.

The present invention will be specifically explained below based on Examples.

<Example 1> A 1.0 ms rotary veneer was immersed in a 50% aqueous solution of dimethyl sulfuric acid for 10 minutes in the dark, then immersed in a 5% aqueous solution of hydrogen peroxide for 2 minutes, and then a frequency of 245
A decolorized veneer was obtained by irradiating it with My'ya waves of 6MHz, output Q, and 4 KW for 25 minutes. Note that the atmospheric conditions during irradiation were I''i humidity of 9996 or higher, y, =.The obtained bleached veneer had L\apeb and L- of 80 at the center in the thickness direction of the intermediate plate.
And one.

<Example 2> A total of 30% dimethyl chloride and chloride was added to a 5% aqueous solution of hydrogen peroxide, and a 5-chill rotary veneer was immersed in the mixed solution at 60°C for 15 minutes to swell. After the decolorization treatment, microwaves with a frequency of 2450 Ml-fz and an output of 2.4 KW were irradiated for 3 minutes to obtain a decolorized sample. In addition,
Microwave irradiation is carried out by blowing live steam onto the surface of the veneer. The internal L- of the resulting bleached veneer was 82 and 1.

<Example 3> A decolorized veneer was obtained in the same manner as in Example 1 except that dimethylformamide was used instead of dimethylsulfate.

<Example 4> Raw sawn cedar wood with a thickness of 20 mm was immersed in an 80% aqueous solution of dimethylformamide at 60°C for 1 hour for swelling treatment, and then immersed in a 7% aqueous solution of hydrogen peroxide for 30 minutes. Then, the frequency of 2450 MH was applied while spraying live steam on the wood.
z, output 2.4 KW (7) Irradiated with microwave for 5 minutes, then heated the wood in 5% hydrogen peroxide for 1 minute, then immersed it in dry air for 1 minute. 2450M
Decolorize the wood by irradiating it with microwaves with an output of 2.4 KW for 5 minutes.

Obtained tl, f: Decolorized wood has its heartwood color bleached at the same time as it dries, and can be used for a long time as a wood with a brown tone when used as a special wood.

Claims (1)

[Claims] fil Wooden page material? A method for decolorizing wood material, which comprises swelling the wood material with a solvent having a greater t1 action than water and decolorizing the wood material with a decolorizing agent, and then irradiating the wood material with microwaves.