JPS587309A - Manufacture of decorative 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 The present invention particularly relates to a method for producing decorative materials with excellent decorative properties.
More specifically, the production of decorative materials with particularly excellent decorative properties, which involves chemically treating thin wood boards with reactants that can react with the hydroxyl groups of wood components, such as esterifying agents and etherifying agents, and then heat-pressing them. Regarding the method.

Conventional methods for strengthening thin wood boards and improving their decorative properties include coating the surface of thin wood boards with synthetic resin paint to form a transparent film, and filling voids such as conduits in thin wood boards with synthetic resin and hardening. There is a known method of forming the material into a decorative material. However, with the former method, it is possible to strengthen the protection of the surface of the thin wood board and add some transparency by partially impregnating it with synthetic resin paint to improve its decorativeness, but the It is difficult to provide enough transparency to create a noticeable contrast between the two, and since the cell structure of the wood laminate remains intact, it is difficult to create a new wood grain appearance by changing the grain of the original wood lamina. It was impossible to form a jin.

On the other hand, in the latter method, voids such as a thin wood plate 0 conduit, etc.
In particular, since the synthetic resin is filled and hardened into the voids in the spring wood, it has high transparency and can be formed into a deep appearance with a noticeable contrast between the spring wood and autumn wood. Because it has a wide variety of tissue structures, it has the problem of easily causing uneven filling of synthetic resin, and like the former, it also changes the grain of the original thin wood board to create a new wood grain appearance. It was impossible to do so.

The present inventors used reactants that can react with hydroxyl groups in wood components (hereinafter referred to as
It was discovered that effects that could not be achieved with conventional techniques could be obtained by chemically treating cellulose (simply called a reactant) to amorphize cellulose, which is mainly a wood component, and then heat-pressing it, and completed the present invention. It's arrived. That is, according to the method of the present invention, it is possible to impart a highly transparent and deep appearance to wood, and it is also possible to change the original wood grain pattern to form a new wood grain pattern, thus significantly improving decorativeness. It is possible to obtain decorative materials. Furthermore, the decorative material obtained by the method of the present invention has excellent physical properties, such as being able to be molded into a three-dimensional shape such as a curved surface.

As already mentioned, the method of the invention comprises the steps of chemically treating the wood veneer with a reactant (first step) and heat-pressing the thus treated wood (second step). Each stage is explained in detail below.

In the first step, the hydroxyl groups of the wood components, particularly cellulose, are chemically modified by contacting the wood veneer with the reactants by suitable means to amorphize the crystalline structure of the cellulose.

There are no particular restrictions on the species or shape of the wood that can be used. However, regarding the shape, a thin plate with a diameter of about 0.3 to 10!111 is preferable in terms of ease of treatment with reactants, high productivity, and high utility value of decorative materials as finished products. .

As mentioned above, the term "reactant" refers to a substance that chemically reacts with the hydroxyl groups of wood components, particularly cellulose, and representative examples thereof include esterifying agents and etherifying agents.

Examples of esterification agents include organic acid anhydrides (for example, acid anhydrides such as acetic acid, propionic acid, and butyric acid), organic acid halides (for example, acids such as the above-mentioned acids, proponic acid, lauric acid, stearic acid, and methacrylic acid). ...logenides, especially acid chlorides), and mixtures of organic acid anhydrides and fatty acids (
For example, a mixture of trifluoroacetic anhydride or hexaacetic anhydride with acetic acid, propionic acid, caproic acid, lauric acid, etc. can be used. These esterifying agents can be used alone or in combination of two or more.

The above-mentioned esterifying agent may contain a catalyst for promoting the reaction with the wood component and/or a solvent for promoting the penetration of the esterifying agent into the wood cell membrane. Examples of such catalysts include sulfuric acid, perchloric acid, urea-ammonium sulfate, zinc chloride, and pyridine, and examples of solvents include acetic acid, benzene, toluene, dimethylformamide, and dinitrogen tetroxide-dimethylformamide. It may be used as a species or as a mixture of more than one species.

Instead of or in addition to being added to the esterifying agent, these catalysts and/or solubilizers may be impregnated in advance into the wood before being treated with the esterifying agent.

Next, as the etherification agent, for example, 1,2 epoxide such as ethylene oxide and propylene oxide, alkyl chloride such as methyl chloride and ethyl chloride, aromatic compound such as benzyl chloride, chloride such as dimethyl sulfate, etc. α-halogen acids such as dialkyl sulfuric acid and monochloroacetic acid, vinyl compounds activated with negative groups such as vinyl cyanide,
Aldehydes such as formaldehyde can be used.

In the case of an etherification agent, as in the case of an esterification agent, a catalyst (for example, an alkaline catalyst such as sodium hydroxide) and a solvent (for example, a solvent similar to that used in the case of an esterification agent) may be appropriately added. It is also possible to pre-impregnate the wood with the etherifying agent before treating it with the etherifying agent, but the latter method is particularly preferred in the case of catalysts.

In addition to the above-mentioned esterifying agents and etherifying agents, examples of reactants that can react with hydroxyl groups include isocyanates (such as methyl isocyanate and ethyl isocyanate).
can be mentioned.

The reactants can be brought into contact with the wood sheets by, for example, immersing the wood in the reactants or by vaporizing the reactants and exposing the wood to this. You can also use methods like under reduced pressure,
The impregnation of the reactant into the wood can be promoted by applying pressure or reducing pressure. The contact time between the reactant and the wood varies depending on the above-mentioned treatment conditions, but when treatment is carried out at normal temperature and pressure, about 1 to 10 hours is usually sufficient.

Through chemical treatment with such reactants, wood components, especially the hydroxyl groups of cellulose, undergo chemical modifications such as esterification and etherification, and the crystalline structure of cellulose becomes amorphous, resulting in wood in a swollen state. (hereinafter referred to as treated wood) is obtained.

At this time, the hydroxyl groups of hemicellulose and lignin, which are the main components of wood along with cellulose, may also undergo similar chemical changes, and in this case, the bonds between wood components are weakened, and the degree of swelling of the wood becomes even more significant.

The degree of amorphization and swelling can be adjusted as appropriate depending on the type of reactant and treatment time, but in general, tissues with large voids such as ducts and tracheids and with thin cell membranes are generally used. The spring wood is more easily impregnated with reactants than the fall wood, and therefore amorphization and swelling are more pronounced than in the fall wood, which leads to the formation of new wood grains, as described below. It is presumed that this is a contributing factor.

The thin wood board chemically treated in the first step is subjected to a second heat pressing treatment.

The heat pressing conditions are appropriately set depending on the type of reactant used, the degree of amorphization and swelling, etc., and are not particularly limited. For example, a temperature of 80 to 250C, 1ok
The object of the present invention can be satisfactorily achieved without thermal deterioration of the wood within 30 minutes under a pressure of y to 200 ky-/d.

This heat-pressing process makes the treated wood denser and more transparent without causing breakage or deterioration, and also causes changes such as enlargement of annual rings, especially in the spring wood, resulting in subtle differences from the original wood. The imparted transparency and the newly formed wood grain combine to form a decorative material with a new wood grain appearance rich in frosty decorative properties.

In addition, the obtained decorative material is densified without causing any deterioration of the wood itself, so it has excellent physical properties such as high wear resistance and flexibility. The added flexibility prevents damage such as cracking even when the wood grain of the thin plate is disturbed or a wood grain pattern is placed on the surface, and it has excellent crack resistance.

Note that the treated wood may be colored in advance with a fluorescent colorant or any other coloring agent before heat-pressing. In this case, since the treated wood is amorphous and swollen, the coloring liquid penetrates easily and uniformly, and after heat-pressing, it becomes even more transparent and It can be finished with a wood grain appearance that is rich in depth and elegance, and its decorative value can be further improved.

Furthermore, during heat-pressing, a plurality of treated wood pieces may be laminated, or plywood such as plywood and treated wood may be stacked and heat-pressed to form a laminate by laminating them together.

In addition, the reason why the above-mentioned new wood grain pattern can be imparted to wood is as follows.
It will be considered in some detail below with reference to the accompanying drawings.

FIG. 1 is a schematic cross-sectional view of wood that has been chemically treated in the first step of the method of the present invention, that is, treated wood (a) and a decorative material (b) obtained by heating and compressing the treated wood.

Treated wood (a) has undergone chemical changes (amorphization due to esterification of hydroxyl groups, etherification, etc.) and structural changes (swelling) as a result of chemical treatment with reactants, and compared to the original wood. It is rich in thermoplasticity. Therefore, the wood is compressed and flattened in the gap A without causing any damage or deterioration. The densified treated wood thus has less light scattered in the voids A, and therefore has increased light transmission.

FIG. 2 is a schematic cross-sectional view of the treated wood (a) and the decorative material (b) obtained by heat compression, similar to FIG. 1, but in order to compare the spring wood part and the autumn wood part, This is a more macroscopic depiction.

The spring wood part with many voids due to conduits, tracheids, etc. has a high degree of amorphization and swelling, and is highly deformed due to compression and densification. In material (b), it is enlarged to W2. These changes in the growth rings create a new wood grain appearance.

In the heat-pressing process, the treated wood can be melted or partially melted by appropriately setting the conditions for treating the wood with the treatment solution and the conditions for heat-pressing.

When this melting occurs, the number density is further improved, resulting in high transparency and a more varied wood grain appearance.
A decorative material with excellent physical properties such as abrasion resistance and crack resistance can be obtained.

Further, during heat-pressing, a mold material having an appropriately shaped pressing surface such as a curved surface or a U-shape may be used. In this case, since the treated wood has thermoplastic properties, curved and
A decorative material formed into a three-dimensional shape such as a bent shape can be formed with good moldability without producing defects such as cracks.

Similarly, even when heat-pressed using a mold material on which an appropriate embossed pattern such as a conduit groove pattern is engraved, the two-embossed pattern can be applied very easily and satisfactorily. Even without using such a shape material, it is possible to form an uneven embossed pattern in which the autumn material part is convex and the spring material part is concave by heating and pressing through the cushioning material.

As mentioned above, the decorative material obtained by the method of the present invention has excellent decorative properties, as well as physical properties such as abrasion resistance and crank resistance, and can be molded into curved or bent shapes. Since it can be easily formed on the body, it can be used not only as a decorative surface material for building materials, furniture materials, etc., but also for a wider range of applications.

The present invention will be explained in more detail with reference to Examples below.

Example 1 A 10m x 10σ veneer of Stubble wood with a thickness of 1cm was treated with 4rnl of acetic anhydride! 2 in a mixture of glacial acetic acid and 30ml of glacial acetic acid.
After pretreatment by immersion for an hour, 30% of acetic acid consisting of 2°-1 glacial acetic acid, 7 m/toluene, and 1-1 perchloric acid was added.
Esterification (
After carrying out the acetylation reaction, it was immersed in a solution of 50-1 glacial acetic acid and 0.89 potassium acetate for 20 minutes and washed with toluene to obtain an acetylated veneer.

Next, this treated veneer was heated and compressed at 180C and 180 kp/i for 10 minutes to obtain a decorative material.

Compared to the veneer before treatment, the resulting decorative wood has a wider grain width in the spring wood area and a narrower wood grain width in the fall wood area, thereby creating a new wood grain pattern. On the other hand, JISK-6714
When the light transmittance was measured based on , the transmittance was 30%.

As a comparative example, a veneer made of the same Siberus material as above was heat-pressed under the same conditions as above without being treated with a treatment solution, and no change in wood grain was observed.
The light transmittance based on ISK-6714 was 3%.

Example 2 The acetylated veneer obtained in Example 1 was immersed for 3 hours in a coloring solution consisting of a 1% aqueous solution of the acidic dye Acid Orange ■ heated to 60C, and then colored with 180C1.
Heat compression was performed at 80ky/crl for 10 minutes. The obtained decorative material had a transparent orange color in the spring wood portion, was uniformly colored to the inside of the wood structure, and had an appearance with excellent decorative properties.

As a comparative example, the untreated veneer used in Example 1 was immersed in the above-mentioned coloring liquid under the same conditions to be colored, and then heat-pressed under the same conditions as above.

The obtained veneer had only a colored surface layer, had no transparency, and was inferior in decorativeness.

Example 3 The same operation as in Example 2 was performed, except that White

The obtained decorative material was not only highly transparent and had a varied wood grain pattern, but also had an elegant, fluorescent appearance.

Example 4 The corners of the acetylated veneer obtained in Example 1 were IOR.
It was inserted between male and female molds having a ■-shaped molding part with a radius of curvature of , and was heat-pressed at 180 C and 80 ky/lyl for 10 minutes to obtain a ■-shaped decorative material. This decorative material had no defects such as cracks, and had a beautiful decorative surface with excellent transparency and a modified appearance of wood.

[Brief explanation of the drawing]

Figures 1 and 2 both show treated wood (a) and decorative wood (
b) is a schematic cross-sectional view of FIG. A...Void area, L...Light, Wl and W2...In tree ring, α1 and α2...
・Annual ring inclination, F...Autumn wood part, S...Spring wood part. Patent Applicant: Daiken Kogyo Co., Ltd. Representative: Seihaku Ao and two other patent attorneys Figure 1 (a) Figure 2 (0) F5 F 111! ! 'I(b) 1/ Figure 2(b)

Claims (1)

[Scope of Claims] 1. A method for producing a decorative material, which comprises treating a thin wood board with a reactant capable of reacting with the hydroxyl groups of wood components to chemically modify the hydroxyl groups, and then heat-pressing. 2. The method for producing a decorative material according to claim 1, wherein the reactant is an esterifying agent or an etherifying agent. 3. The method for producing a decorative material according to claim 1, which comprises heating and pressing it into a three-dimensional shape such as a curved shape or a bent shape.