JPH0369708B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention is applicable to packaging materials, various cosmetic materials, stationery and office supplies,
This invention relates to urethane resin-impregnated wooden sheets that have various uses such as box materials, decorative materials, and toys. [Problems to be Solved by the Invention] Conventionally, wood sheets (so-called veneer boards) obtained by thinly slicing wood into sheets have been used as a material for wrapping natto, dumplings, etc. However, the veneer itself has the property of being easily torn in the vertical direction and cracking when bent in the horizontal direction. As long as it is used as a packaging material for natto, dumplings, etc., such drawbacks do not pose much of a problem. However, we are currently in an era of diversification. Consumers are demanding new materials in everything. In order to meet the diversified demands of consumers, the present inventor conducted extensive research into developing new uses for wood veneers. However, the problem here is that the wood veneer tends to tear vertically and cracks when bent horizontally. The present inventor conducted research on bonding a veneer and a backsheet made of plastic or thin material. However, although the above-mentioned drawbacks of veneer boards can be improved by laminating such back sheets,
Instead, the woody feel of the veneer itself was lost. In the next step, we conducted research on coating or impregnating various synthetic resins. Various resins, such as phenolic resins,
We conducted experiments on vinyl acetate resin, divinyl phthalate resin, melamine resin, and urea resin, and discovered that urethane resin was optimal, leading to the present invention. [Means for Solving the Problems] The present invention relates to a polyurethane resin-impregnated wood sheet characterized by impregnating a sheet material obtained by thinly slicing wood into sheet shapes with a urethane resin. Furthermore, a back sheet is formed over the entire surface of the above polyurethane resin-impregnated sheet material of the present invention, or one of the urethane resin-impregnated hardwood sheets is formed.
Leaf veins may be formed on the parts. The urethane resin-impregnated wooden sheet of the present invention has the advantage of not tearing or cracking, and has a toughness that allows it to be bent freely. The reason why we used thinly sliced wood sheets as they were was to preserve the unique flavor that takes advantage of the wood skin and grain, and the reason why we used urethane resin as the soaking resin was to preserve the wood skin and grain. This is because it has the property of imparting flexibility to the sheet material without damaging it, and it is easy to handle, and the wood sheet impregnated and adhered to the wood sheet does not cause any skin damage even when handled. Any kind of urethane resin can be used. Polyurethane dispersion for textile processing is particularly suitable, and the wood can be softened by soaking it in the resin solution and drying it, or by gluing backsheets or leaf veins while still wet, and bending it like an origami crane. It is flexible enough to be easily made even on materials with a lot of water, has a strong film that does not yellow, is resistant to heat, is practical in the range of -40 degrees to 200 degrees, and is difficult to swell in water. Form. By doing this, it was possible to bend something like paulownia wood without breaking the paulownia wood, and it was also possible to bend something made of paulownia wood sheets without causing any cracks.
The soaking time will vary depending on the thickness of the wood sheet, but it is best to soak it for at least 1 minute. A back sheet made of urethane resin that is fixed in or on the skin is used for decoration and to improve strength, but it can also be used to expand the size of the material or to form multilayered materials. In either case, the urethane resin is fixed or It will be used as an adhesive means, and has tensile strength,
Excellent physical properties such as elongation and hardness are utilized. Also,
A disaster prevention agent (for example, Pyrogard F800.10%, trade name) may be used at the same time. The method of use is to mix it into a resin liquid or spray it. For example, polyethylene film, polyvinylidene chloride film, cellophane cloth, paper, leaves, or other plate, sheet, or film forms, or the sheet form itself can be used as the back sheet or leaf vein to be fixed or adhered. In addition, the thickness of the wooden wood sheet is preferably about 0.03 mm to 0.3 mm. [Example] 1 Commercially available wood (100 pieces of polymerized wood with a thickness of about 25 mm) was used as a sheet material and was treated with an 80% aqueous solution of polyurethane dispersion Elastron DP-200 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.). The material was immersed in water for 5 to 10 minutes, pulled up, and dried at 100°C for 2 to 3 minutes to obtain a wood sheet. This warped wood sheet did not easily tear in the longitudinal direction of the grain, and did not form hangnails or creases when folded in the horizontal direction. 2 The same sheet material (0.2 mm thick) as in Example 1 was immersed in an 80% aqueous solution of polyurethane dispersion with the same components for 5 to 10 minutes, and after being pulled up, the leaves were 98%
100g of sodium hydroxide was boiled in a caustic soda solution diluted with 2 parts of water, the mesophyll was removed, the leaf veins formed were scattered, and the leaves were naturally dried at room temperature for 24 hours to obtain a wood sheet. The leaf veins are fixed in urethane resin through the veins (see Figure 1),
The Kyogi sheet showed the same results as in Example 1. 3 A wood sheet obtained by coating the material obtained in Example 2 with a cellophane film was obtained.
In addition, before drying, polymerization may be carried out using the adhesive force of the urethane resin with or without intervening leaves. 4 A number of sheets similar to those in Example 1 were soaked in an 80% aqueous solution of polyurethane dispersion for 5 to 10 minutes.
The ends of the soaked pieces were overlapped and glued together to obtain a large-sized wooden sheet. FIG. 1 shows an embodiment in which leaf veins are laminated on a portion of a wooden sheet according to the present invention, where 1 is a resin-impregnated wooden sheet and 4 is a leaf vein. Figures 2 to 4 show the bookmarks made using the bookmark sheet according to the present invention. In Figure 2, an origami crane X was made as an origami material, and in Figure 3, the bookmark sheet was cut into strips and a bookmark Y was made. Figure 4 shows an example of an electric light umbrella Z whose side surface is decorated with a wooden sheet. Further, FIG. 5 shows an example in which three wood sheets 1 are layered, and in the case of layering, if the grain of the wood is uneven, the curl can be eliminated by changing the direction and stacking them one on top of the other. The wood sheet 1 may be layered in any number of layers. [Effects] Therefore, according to the present invention, for example, toys, doll origami, models, etc., covers of albums, notebooks, notebooks, etc., stationery supplies, umbrellas for electric lights, wrapping paper, wallpaper, etc.
The wood sheet can be used in a wide variety of applications, such as accordion curtains, building materials such as desk decorations, folding boxes, waste boxes, paper boxes, containers for confectionery, cigarettes, alcohol, etc., packaging boxes, etc. Example 3 and Comparative Examples 1 to 5 In Example 3, a 0.1 mm thick sliced beech material was treated in the same manner as in Example 1 to obtain a wood sheet with an impregnated amount of urethane resin of 38% (w/w). In Comparative Examples 1 to 5, beech sliced material
Each 0.1 mm thick sheet was treated with the resin liquid to obtain a wood sheet with the same resin impregnation amount of 38% (w/w). Regarding the wooden sheets obtained in Example 3 and Comparative Examples 1 to 5, the folding strength (JIS-
P8115), hardness (ASTM D-638) and hardness (ASTM D-785). The results are shown in the table.

[Table] Keiki sheets impregnated with melamine resin, phenolic resin, urea resin, diallyl phthalate resin,
It was crisp and warm like a hard, thin rice cracker. Therefore, it broke when bent at 90 degrees, and its bending strength was zero. The appearance and texture of the wood sheets of Example 3 and Comparative Example 1 were good, but those of Comparative Examples 2 to 5
The wooden sheet was crisp and the wood texture was not sticky.

[Brief explanation of drawings]

The drawings show examples of the wooden sheet according to the present invention, and FIG. 1 is a sectional view showing a structural example of one aspect of the present invention, and FIGS. 2 to 4 are perspective views of three types of usage examples. FIG. 5 is a sectional view showing another structural example. 1... Keiki sheet, 4... Leaf vein, 5... Back seat.

Claims (1)

[Scope of Claims] 1. A urethane resin-impregnated wood sheet characterized by impregnating a sheet material obtained by thinly slicing wood into sheets with urethane resin. 2. A urethane resin-impregnated wood sheet, characterized in that a sheet material obtained by thinly slicing wood into sheets is impregnated with urethane resin, and leaf veins are formed on a portion of the urethane resin-impregnated wood sheet.