JPS587310A - 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 relates to a wood material that is particularly excellent in rotting and insect repellent properties and two-dimensional stability, and more specifically, the present invention relates to a wood material that has excellent antiseptic and insect repellent properties and two-dimensional stability. The present invention relates to a wood material in which a plurality of treated wood laminates are integrated via an adhesive after being chemically treated with a reactant to be obtained.

Laminated wood and laminated wood are wood and its processed materials.

Wood materials are light, strong, and have unique physical properties and textures, and are used not only as construction materials and furniture materials, but also for a wide range of other uses.

However, on the other hand, it is easy to rot due to erosion by various fungi and insect damage such as termites, and it is not as airtight as it is today.
In residential environments where heating devices have become more widespread, the occurrence of such rot has actually increased, and has become a major problem as one of the causes of decreased durability of wood materials.

In addition, while wood has the so-called breathability of absorbing and dissipating moisture depending on the surrounding environmental conditions, it can warp, twist, expand and contract due to repeated absorption and dissipation of moisture. It has the essential drawback of causing deformations such as.

Is it common practice to impregnate wood materials with preservatives and insect repellents such as creosote oil to improve the problem of insect damage? However, it is difficult to treat the inside of the wood, and since it involves adding oily substances, it has disadvantages such as further increasing the flammability of the wood.

Furthermore, it is known that it is effective to chemically modify the hydroxyl groups in the wood components by subjecting the wood material to a chemical treatment such as acetylation in order to improve the problem of deformation. However, since wood is not made of a single component, but has a complex composition and a complex structure,
The method of chemically treating wood materials requires an extremely long time for the reaction as the diameter of the material increases, and it is extremely difficult to remove excess reaction liquid and catalyst. There is a problem that it is difficult and impractical to carry out industrial production due to deterioration of properties and the like.

The present inventors investigated the use of reactants (hereinafter referred to as
(simply referred to as reactants).

As already mentioned, the method of the present invention consists of the steps of chemically treating the wood laminates with a reactant (first step) and integrating the wood thus treated with an adhesive (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 reactants by suitable means.

There are no particular restrictions on the species or shape of the wood that can be used. However, regarding the shape, it is desirable to use a thin plate of about 0.3 to 1Q mm in terms of ease of treatment with reactants and high productivity.

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). halides, especially acid chlorides), and mixtures of organic acid anhydrides and fatty acids (for example mixtures of trifluoroacetic anhydride or chloroacetic anhydride with acetic acid, propionic acid, caproic acid or lauric acid, etc.). . These esterifying agents can be used alone or in a mixture of two or more. A solvent may be added to promote penetration of the wood into the wood cell membrane. Examples of such catalysts include sulfuric acid, perchloric acid, urea-ammonium sulfate, fatty acid salts, and dimethylformamide, and solvents include acetic acid, benzene, toluene, dimethylformamide, and dinitrogen tetroxide-dimethylformamide. Each may be used as a mixture of two or more.

These catalysts and/or solvents may be impregnated in advance into the wood before being treated with the esterifying agent, instead of or in addition to the esterifying agent.

Next, examples of etherification agents include 1.2 epoxides such as ethylene oxide and propylene oxide, alkyl chlorides such as methyl chloride and ethyl chloride, aromatic chlorides such as benzyl chloride, and dimethyl sulfate. 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 etherification agent before treating it with the etherification agent, but the latter method is particularly preferred in the case of catalysts.

In addition to the above-mentioned esterifying agents and etherifying agents, reactants that can react with hydroxyl groups include incyanates (for example, methyl isocyanate, ethyl isocyanate, etc.)
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 the treatment is carried out at normal temperature and pressure, it is usually about 1 to 10 hours.

In particular, when a fatty acid salt is used as a catalyst and the treatment is carried out under certain conditions, the treatment can be carried out in a few minutes.

By chemical treatment with such reactants, wood components,
In particular, the hydroxyl groups of cellulose undergo chemical modifications such as esterification and etherification.

A plurality of thin wood boards chemically treated in the above first step are laminated and integrated to form a laminate.

That is, an adhesive is applied to the surface of the required thin wood boards, the adhesive is laminated, the adhesive is cured under pressure, and the wood material is formed by integrating the adhesive.

Depending on the type of adhesive, it may be necessary to heat it when pressurizing it.

The structure of wood veneer can be either a plywood structure in which the fiber direction of each sheet is orthogonal, an LVL structure in which adjacent fiber directions are parallel to each other, or an intermediate structure between plywood and LVL in which the fiber directions are orthogonal to each other in every few sheets. good.

Next, the test results board for the wood material mentioned above was immersed in a catalyst solution consisting of a 15% potassium acetate solution humidified at about 60°C, the catalyst was impregnated into the veneer, and the board was dried. This veneer was immersed in an acetic anhydride solution heated to 1.00"G-120□℃ and reacted for 30 minutes, and the weight increase rate (apparent acetylation rate) after washing and drying was approximately 25%.
An acetylated veneer was obtained. Thirty-five of these acetylated veneers were laminated and bonded using a phenolic resin adhesive so that the fiber orientation of the veneers was parallel, and the cross section was 10 cm x 10 CrrL.
A laminated wood board having a columnar LVL configuration was obtained.

Using the wood thus obtained as a sample, we tested it at 4 temperatures and 2 hours using a method of cultivating Ophthalmia nigra, which is a fungus that causes the decay of wood.
When the weight loss rate was measured after being left at 6℃ and humidity of 70℃ for 3 months, there was almost no weight loss, about 1 inch.
It was confirmed that the untreated rice chestnut wood under the same conditions showed a weight loss of about 15%, while it was confirmed to have extremely excellent preservative power.

In addition, when the wood material was buried in a bundle of Japanese termites and a four-month termite test was conducted to measure the weight loss rate, it was found to have an excellent termite-proofing performance with a weight loss of 0.

Furthermore, when we measured the dimensional change (elongation rate) when an equilibrium state was reached under conditions of 20℃ and 65cm humidity with respect to the dimensions in an absolutely dry state, we found that 0.5% and 0.7% in each direction, and has excellent dimensional stability, compared to untreated rice chestnut wood which showed values of 2.5% and 3.7%, respectively, under the same conditions. It was recognized that they have a sexual nature.

In this way, the present invention has antiseptic and insect repellent properties.

In order to obtain a wood material with good dimensional stability, thin wood boards are treated with a reactant that can react with hydroxyl groups, and the treated thin wood boards are laminated together using multiple branches and an adhesive. Compared to the case of treating the inside, it is possible to treat the inside uniformly, and the treatment time can also be greatly shortened.

In addition, excess reaction liquid and catalyst can be easily removed for processing thin plates, and the idiosyncratic properties of thin plates and laminates are not deteriorated.

Since the obtained columnar and plate-shaped laminates are uniformly treated to the inside, their dimensional stability will not deteriorate even if they are cut or processed with patterns for joining, and the above-mentioned As such, it has good anti-termite and insect-repellent properties, so it can be used for a wide range of purposes.

Claims (2)

[Claims] (1) A wood material made by treating thin wood boards with a reactant that can react with the hydroxyl groups of wood components to chemically decorate the hydroxyl groups, and then laminating several horizontally treated wood thin boards together using an adhesive. Material. (2) The wood material according to claim 1, wherein the reactant is an esterifying agent or an etherifying agent.