JPS5825957A - Manufacture of laminated 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 method for manufacturing a laminate coated with a layer of lignocellulose material such as a wood material having a dense surface and excellent wear resistance, water resistance, etc.

Laminated materials, which are made by laminating wood materials on a plywood surface, are used in a wide range of applications such as furniture and construction materials. However, the conventionally used wooden materials have the drawbacks that their surfaces are easily damaged and that they are susceptible to expansion and contraction under the influence of moisture. For this reason, measures such as painting the surface of the wood material to protect it have been taken, but there have been no reports of success in improving the essential surface properties by modifying the components of the wood material itself. Furthermore, when conventional wood materials are used to create decorative materials by carving uneven patterns or embossed patterns on their surfaces by heat-pressing molding, the surface is susceptible to damage such as cracks. Due to its elasticity, the corners of the uneven pattern are rounded, making it difficult to obtain a sharp shape. This is because conventional wood materials have almost no thermoplastic properties. This also means that when trying to form a compact with a dense surface, harsh conditions (e.g. 250°C or higher, 20k
g/cm2 or more) is required, and
Such harsh conditions tend to cause carbonization and brittleness of the wood material.

As a result of extensive research in view of these problems, the present inventors have discovered that lignocellulose materials in the form of fibers, particles, sheets, etc., treated with a reactant that can react with the hydroxyl groups in the components, are placed on the surface of the plywood. If this is heated and pressed, it is possible to form a dense coating layer on the plywood with excellent wear resistance and water resistance, and furthermore, uneven patterns, embossed patterns, etc. can be engraved during heat pressing. It has been found that molded products with desired patterns can be formed with good reproducibility even under mild conditions.

The method of the present invention provides the above-mentioned advantages because the hydroxyl groups in the components are chemically modified to impart thermoplasticity to lignocellulosic materials such as wood materials. It is possible to avoid surface cracks, and it is also possible to form even sharply shaped uneven patterns and embossed patterns.

That is, the present invention provides for chemically modifying the hydroxyl groups in the lignocellulosic material component by treating the lignocellulosic material with a reactant that is capable of reacting with hydroxyl groups, and for modifying the resulting modified cellulosic material. The present invention relates to a method for manufacturing a laminated material, characterized in that the laminated material is placed on the surface of a plywood board and then heat-pressed to integrate the laminated material.

As the lignocellulose material, wood materials such as fibrous, powder, flake, sheet, or thin plate, which are used for the purpose of decorating and/or protecting the plywood surface, can usually be used. A wide variety of herbs and other cellulose and lignin based materials can also be used.

In carrying out the invention, the lignocellulosic material is first treated by suitable means with a reactant capable of reacting with hydroxyl groups. Here, the reactant refers to a substance that chemically reacts with the components of the lignocellulose material, particularly the hydroxyl groups of cellulose, and representative examples thereof include esterification agents and etherification 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, lauric acid, etc.). These esterifying agents can be used alone or in combination of two or more.

The above-mentioned esterification agent includes a catalyst such as sulfuric acid perchloric acid and/or a catalyst to promote the reaction with the components of the lignocellulose material.
Alternatively, a solvent such as toluene acetate may be added to promote the penetration of the esterifying agent into the lignocellulosic material.

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

Next, as the etherification agent, for example, 1.2 epoxides such as ethylene oxide and propylene oxide, alkyl halides such as methyl chloride and ethyl chloride, and aromatic halides such as benzyl chloride 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 lignocellulose material before treatment with the etherification agent, although 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 isocyanenite, etc.)
can be mentioned.

The reactant can be contacted with the lignocellulosic material by, for example, immersing the lignocellulosic material in the reactant or by vaporizing the reactant and exposing the lignocellulosic material. Further, such a method can be carried out under reduced pressure, under increased pressure, or by a reduced pressure method to promote impregnation of the reactant into the lignocellulosic material.

Through chemical treatment with such reactants, the components of the lignocellulosic material, particularly the hydroxyl groups of cellulose, undergo chemical modifications such as esterification and etherification, and the crystalline structure of cellulose becomes amorphous, thus changing its thermoplastic properties. A lignocellulose material is obtained.

The lignocellulose material modified by the above operation is placed on the plywood by scattering or placing. in this case,
Adhesion with lignocellulose heat board △ In order to ensure integration, the plywood may be coated with a suitable adhesive, and in order to improve the adhesion between lignocellulose materials and the plywood. The lignocellulosic material may be impregnated with the adhesive.

Plywood made of wood materials such as wood fiberboard, plywood, and particle board is suitable, but depending on the heat pressing conditions described below, various materials such as asbestos cement board, metal board, synthetic resin board, etc. may be used. Of course, the shape of the laminated surface is not limited to a flat surface or a curved surface, but may have various uneven patterns.

After the modified lignocellulose material is placed on the plywood, it is heated and pressed. By this heat-pressing molding, the lignocellulose material placed on the plywood is densified due to its imparted thermoplastic properties, and is easily molded into the shape of the base plate, so that it is laminated and integrated with the plywood.

The heat pressing conditions are appropriately set depending on the type of reactant used, the degree of amorphization, etc., but usually even under relatively mild conditions of a temperature of 80 to 250 °C and a pressure of 2 kg/crn or more. can be done.

In addition, when heat-pressing is carried out, a shape material that roughly corresponds to the shape of the laminated surface of the base plate is usually used, but these shapes are also engraved with uneven patterns or embossed patterns that do not exist on plywood. can also be used. In this case, the lignocellulose material layer can be engraved with an uneven pattern or embossed pattern depending on the mold material, but as mentioned above, the lignocellulose material according to the present invention has thermoplastic properties, so it can be easily reproduced. These patterns can be engraved with ease.

The characteristics of the method of the present invention and the laminate obtained by the method of the present invention are listed below.

1) Since the surface of the base plate is coated with a modified dense lignocellulose material, it is less susceptible to damage such as wear and scratches.

2) The modified lignocellulose material does not easily swell or undergo deformation such as warping even when exposed to water or humidity, resulting in a laminated material with excellent moisture and water resistance.

3) Since the modified lignocellulose material has thermoplastic properties, it has good moldability, and a laminate with an arbitrary surface shape can be obtained.

4) For the same reason as mentioned above, molding can be performed under relatively gentle heating and pressing conditions, and therefore carbonization and brittleness of lignocellulose materials such as wood materials can be avoided.

Hereinafter, specific embodiments of the present invention will be described in detail based on the drawings.

[Example 1] Wood fibers obtained by defibrating wood with a pulper or the like were pretreated by immersing them in a mixed solution consisting of 5 parts of acetic anhydride and 80 parts of glacial acetic acid for 2 hours, and then dipping them into acetic anhydride. 20 parts, glacial acetic acid 5
The wood fibers were immersed for 4 hours in a treatment solution consisting of 1 part and 0-1 part perchloric acid to carry out an esterification (acetylation) reaction, then washed and dried to chemically modify the hydroxyl groups in the wood fibers. As shown in Fig. 1, the wood fiber a of the lever is cut with a router to form a frame-shaped decorative groove 2 with a depth of 5 strips at the center of the surface and a curved decorative surface 3 around the surface side. C. Next, the base plate 1 on which the wood fibers a are scattered and deposited,
It has an uneven shape that substantially corresponds to the uneven surface shape of the base plate 1,
In addition, using a mold material 4 having a fine wood grain-like embossed pattern (not shown) engraved on its uneven surface, it was heated at 180°C for 10
The laminated material 5 was obtained by heating and pressing for 5 minutes under heating and pressing conditions of kg/cm2.

The surface of the thus obtained laminated material 5 is covered with a dense wood fiber layer a' and is not easily damaged by abrasion, etc., and the uneven shape of the shape material and the wood grain-like embossed pattern provided on the uneven surface However, both were reprinted with good reproducibility and had excellent cosmetic properties.

[Brief explanation of the drawing]

FIGS. 1(a) to ω) are cross-sectional views of the manufacturing process of the laminated material. 1... Base plate, 2... Edge decorative groove, 3...
...Curved decorative surface, 4...Mold material, 5...
...Laminated wood, a...Wood fiber, a'...
...Wood fiber layer. Patent applicant: Daiken Kogyo Co., Ltd., agent Patent attorney: Aobai Ao et al. 2-31;

Claims (3)

[Claims] (1) treating a lignocellulosic material with a reactant capable of reacting with hydroxyl groups to chemically modify the hydroxyl groups in the lignocellulosic material components, and placing the thus obtained modified lignocellulosic material on the surface of the plywood; A method for manufacturing a laminated material, which comprises heating and pressing the materials to integrate the laminated materials. (2) The method for manufacturing a laminated material according to claim 1, wherein a mold material having a shape substantially corresponding to the surface shape of the base plate is heat-pressed. (3) The method for manufacturing a laminated material according to claim 2, which uses a mold material having an uneven pattern or an embossed pattern carved thereon that does not exist on the base plate.