JPS608008A - Manufacture of dyed 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 dyed veneers and other dyed wood used as materials for laminated decorative veneers.

[Background technology]

The method for manufacturing dyed wood such as dyed veneer is to decolorize the wood by applying hydrogen peroxide using a roll coater, etc., and then apply dye using a roll coater etc. to obtain dyed wood (wood printing type decolorization). dyeing techniques) are being developed. According to this manufacturing method, waste hydrogen peroxide and dye waste can be reduced compared to the case where wood is bleached or dyed by impregnating hydrogen peroxide or dye into the wood by dipping.

However, in the above manufacturing method, washing with water before dyeing is necessary.
Even if you wash it with hot water, a large amount of hydrogen peroxide will remain in the wood (several thousand to 111), so the dye will be oxidized by hydrogen peroxide and the resulting dyed wood will be unevenly dyed. There was a problem in that there was a risk that the product would become yellow or discolored.

[Purpose of the invention] This invention is aimed at preventing the dyed wood obtained from being unevenly dyed,
The purpose is to provide a method for producing dyed wood that does not become discolored.

[Disclosure of the Invention] In order to achieve the above-mentioned object, the present invention decolorizes wood with hydrogen peroxide and then dyes it to obtain dyed wood. The gist of this paper is a method for producing dyed wood that uses salt to lower the hydrogen peroxide concentration in the wood. This invention will be explained in detail below.

First, hydrogen peroxide is applied to the wood using a roll coater or the like to bleach the wood, and if necessary, the wood is washed with water or hot water to produce bleached wood. In order to effectively decolorize the wood, if necessary, permeate the wood with alkali before applying hydrogen peroxide to the wood, or perform curing after applying hydrogen peroxide, etc., as appropriate. Hydrogen peroxide is usually applied in the form of an aqueous solution.

Next, as shown in FIG. 1, a solution 1 of sulfurous acid and/or its alkali metal salt as a pretreatment agent for dyeing is applied to the wood 3 using a roll coater 2 or the like. Then, 1. The amount of hydrogen peroxide remaining in the wood is usually about 3000 ppm or less. Most preferably, sulfite or sodium bisulfite is used as the pretreatment agent. This is because it is resistant to oxidation by the acids contained in the wood itself and has good permeability into the wood.

Depending on the degree of penetration of the pretreatment agent into the wood, the wood may be heat-treated to promote penetration or the time until dyeing may be adjusted as necessary.

Thereafter, a dye is applied to the wood using a roll coater or the like, and heat treatment is performed as necessary to increase the penetration rate of the dye to obtain dyed wood.

Since the dyed wood thus obtained contains very little hydrogen peroxide, there is very little risk of uneven dyeing or discoloration.

In the above description, hydrogen peroxide, a pretreatment agent, and a dye were applied, but these may also be applied to and penetrated into the wood by dipping, etc. Next, Examples and Comparative Examples will be described.

(Example) After decolorizing a 1.0 mm thick veneer made from the heartwood of Agatis with hydrogen peroxide, 3.0% sodium hydrogen sulfite (Na1lSO2) was applied at a rate of 140 g/nr and heated at 100°C. The mixture was heat-treated for 30 minutes.

Next, dye (0.6% C,I, Ac1d
After applying Or-ange 51), the wood was heated at 100° C. for 2 hours to obtain dyed wood.

(Comparative example) After decolorizing the same veneer as used in the example with hydrogen peroxide and applying the same dye as used in the example,
A dyed wood was obtained by heat treatment at 100° C. for 2 hours.

The plan view of the dyed wood obtained in the example and comparative example is shown in the second figure.
Figure 3 (al) and Figure 3 (al). Figure 3 fa
In 1, the shaded area 4 indicates a discolored area. The amount of residual hydrogen peroxide in the dyed wood obtained in the example was 2000 pp.
m, and the one obtained in the comparative example is 4()000pp
It was very small compared to the previous year. For both dyed wood, line A in Figure 2 (a) and line A in Figure 3 (a)
The half value of a along the straight line B at 1 was measured. Here, a
Half value is one of the color values and is an index representing redness. The results are shown in FIG. 2 (bl) and FIG. 3 (bl).

Figure 2 (a), (bl and Figure 3 fal, (
From b), it can be seen that the dyed wood obtained in the example has less uneven discoloration than the dyed wood obtained in the comparative example.

〔Effect of the invention〕

In the method for producing dyed wood according to the present invention, as described above,
Since pretreatment is performed before dyeing, there is very little risk that the resulting dyed wood will be unevenly dyed or discolored.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the application state of the pretreatment liquid, and Figure 2 (al
is a plan view of the dyed wood obtained in the example, and the same ta
Graph showing the a* value along straight line A at +, 3rd
(a) of the figure is a plan view of the dyed wood obtained in the comparative example, and (middle) is a graph showing the a value along the straight line B in the same (al). ■...Pre-treatment agent 3...・Wood agent Patent attorney Takehiko Matsumoto Figure 1 (a) (b) Figure 2 (a) (b) Figure 3

Claims (3)

[Claims] (1) When bleaching wood with hydrogen peroxide and then staining it to obtain dyed wood, it is recommended to lower the hydrogen peroxide concentration in the wood using sulfite and/or its alkali metal salts before dyeing. A distinctive method of manufacturing dyed wood. (2) The method for producing dyed wood according to claim 1, wherein the wood is a veneer. (3) The method for producing dyed wood according to claim 1 or 2, wherein the alkali metal salt of sulfite is sodium bisulfite.