JPS62160202A - Manufacture of colored 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 (Industrial Application Field) The present invention relates to a method for producing colored wood used for furniture, construction materials, etc.

(Prior art and its problems) One method of coloring wood is to paint it, but this method does not allow coloring to the inside of the wood, so there are no scratches or chips on the surface of the wood product. When this occurs, the color of the wood fabric becomes exposed and the product value is significantly reduced.

For this reason, as described in Japanese Patent Publication No. 49-39806, a method was developed in which wood was impregnated with furan-based resins such as furfuryl alcohol or furfural to color the wood. You can get wood that is highly durable.

However, the storage period of this furan-based resin coloring liquid is short, and for example, 0% furfuryl alcohol solution has a short shelf life.
If 0.1 part by weight of hydrochloric acid is mixed, the usable period is 1 day. Therefore, in the invention described in the above publication,
For example, it has been disclosed that the storage period of the solution can be extended by adding 0.2 parts of ferric nitrate as a catalyst and 1 part by weight of lactic acid as a complexing agent to a 10% aqueous solution of furfuryl alcohol. Even with this method, the usage period is 4
Moreover, resinization has started partially from the time of mixing, which causes problems in handling, and when coloring the wood, color unevenness tends to occur, resulting in variations in the quality of the product. There is a problem in that the degree of freedom in coloring is limited to a narrow range because the concentration of the resin liquid and the catalyst that control the shade of coloring are limited.

The present invention solves these problems and provides a method for producing colored wood that improves productivity and handleability, makes it easy to control the shade of coloring, and is less likely to cause color unevenness.

(Means for Solving the Problems) In order to achieve the above object, the method for producing colored wood according to the present invention includes impregnating wood with a solution of a furan monomer or its initial condensate, and then impregnating the wood with an organic acid or This method is characterized in that an inorganic acid is brought into contact with the surface of the wood, and the organic or inorganic acid is diffused into the interior of the wood to polymerize and harden the furan monomer or its initial condensation solution.

In the present invention, the species of wood to be colored is not limited, but it is preferable that the wood veneer has a thickness of five fins or less in order to enable uniform coloring to the inside.

Furthermore, the moisture content of the wood is not limited either, and either green wood or dried wood can be used.

The wood coloring solution may be an aqueous solution containing 0.5% or more, preferably 1 to 30%, of a furan monomer such as furfuryl alcohol or furfural, or an initial condensate thereof, or an organic solution such as methanol or acetone. A solvent solution is used, and if necessary, a trace amount of organic or inorganic bases may be added as a stabilizer to these aqueous or organic solvent solutions.

Catalysts that promote the polymerization reaction of furan monomers or their initial condensates include hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, P-)
Aqueous solutions of inorganic or organic acids such as luenesulfonic acid and ammonium chloride, or gases such as hydrogen chloride are used.

The concentration range of the catalyst used varies depending on the type of catalyst used, and depending on the concentration, the intensity of coloring of the wood can be adjusted.

Also, depending on the type of catalyst, wood can be colored in a desired shade of color from white-brown to black. For example, if you want to dye it a deep color, you can use a catalyst such as sulfuric acid or P-toluenesulfonic acid, and if you want to dye it a light color, you can use a catalyst such as sulfuric acid or P-toluenesulfonic acid. Hydrochloric acid etc. may be used for this purpose.

The method for impregnating the wood with the solution of the furan monomer, etc. may be any of the immersion method, the reduced pressure method, the pressurization method, or the reduced pressure method, but if the wood is raw material, the immersion method and diffusion method may be used. It is preferable to adopt it.

In this way, after the wood is impregnated with the coloring solution, the catalyst is brought into contact with the wood surface. This catalyst contact method is as follows:
Any method may be used, such as a dipping method or a method of coating the wood surface by spraying or brushing, as long as the acid solution adheres to the wood surface impregnated with the coloring solution. Alternatively, a method of bringing acid vapor into contact with the wood surface can also be adopted.

After the catalyst is brought into contact with the surface of the wood impregnated with the coloring solution, the wood is heated at room temperature to 260'C to
When heated for 2 hours or more, the catalyst diffuses into the wood and rapidly polymerizes the coloring solution such as furan monomer or furfural impregnated inside the wood, resulting in uniformly colored wood. That's what you get.

In addition, if it is necessary to remove the acid remaining in the wood, the wood after heating may be neutralized and washed with an alkali. This cleaning method uses an alkaline aqueous solution, for example, 0.5
This is done by injecting a % sodium hydroxide aqueous solution into the wood using a vacuum or pressurization method, and then drying it.

(Example) Next, examples of the present invention will be shown.

Example 1 After injecting a 5% furfuryl alcohol aqueous solution into a dry birch veneer (100 x 100 mm) with a thickness of 2 mm using a vacuum pressurization method, 0.0% was immediately applied to the surface of the veneer. IN hydrochloric acid was applied with a brush, and the unit was then dried for 20 minutes with a dryer in an atmosphere of 170°C, to polymerize and harden the furfuryl alcohol aqueous solution impregnated inside.

The thus obtained birch veneer changed from its base color of white to a walnut-like color, and the color was uniformly colored even inside.

Example 2 A birch veneer having the same thickness and shape as in Example 1 was impregnated with a 10% furfuryl alcohol aqueous solution, and then immediately immersed in a P-toluenesulfonic acid aqueous solution for 5 seconds.

Next, this veneer was dried for 20 minutes using a dryer in an atmosphere of 170° C., and the furfuryl alcohol aqueous solution impregnated inside was polymerized and cured.

The thus obtained birch veneer was colored uniformly black even inside.

(Effects of the Invention) As described above, according to the method for producing colored wood of the present invention, after impregnating wood with a solution of a furan monomer or its initial condensate, an organic acid or an inorganic acid is applied to the surface of the wood. The method is characterized in that the furan monomer or its initial condensation solution is polymerized and cured by bringing the organic acid or inorganic acid into contact with the wood and diffusing the organic acid or inorganic acid into the interior of the wood. The coloring solution, which consists of a chemical compound, and the organic or inorganic acid that is the hardening agent are used separately in an underground state, so the coloring solution can be used semi-permanently regardless of the storage period. Furthermore, since only this coloring solution is impregnated into the wood in advance, it can be easily and uniformly impregnated into the inside of the wood, and color unevenness due to uneven impregnation or polymerization is less likely to occur, resulting in uniformly colored wood. It is something that can be done.

In addition, since it is not related to the storage period, it is possible to use a low-concentration coloring solution, and by selecting the type and concentration of the catalyst, the shade of color to be applied to the wood can be controlled, and in addition, the cost is low. This allows for efficient production of colored wood.

■Procedural amendment dated March 21, 1986 2, Title of invention Method for producing colored wood 3, Relationship with the case by person making the amendment Patent applicant Address Name Daiken Kogyo Co., Ltd. 4, Agent 5, Amendment Date of order: Showa, month, day 6,
Subject of amendment Column 7 of the detailed description of the invention in the specification;
Contents of the Amendment In the description of the amendment, the statement "Aqueous solution containing 0.5% or more, preferably 1 to 30%" on the 3rd to 4th lines of page 4 is amended as follows.

an aqueous solution containing rO, 05-30%, preferably 0.5-10%.''

Claims (1)

[Claims] After impregnating wood with a solution of a furan monomer or its initial condensate, bringing an organic acid or an inorganic acid into contact with the wood surface,
A method for producing colored wood, which comprises diffusing the organic acid or inorganic acid into the interior of the wood to polymerize and harden the furan monomer or its initial condensation solution.