JPS624212B2 - - Google Patents

Description

Detailed Description of the Invention The present invention focuses on the characteristics of polyolefin-based synthetic resins, such as polyethylene, which have a low thermal melting temperature of around 80°C and high shrinkage among various synthetic resins, and utilize this property. The purpose is to produce a decorative sheet-like article having an uneven pattern.

Decorative sheet-like products with this type of uneven pattern are widely used in the field of wallpaper, etc.
In addition to conventional methods such as chemical embossing method, mechanical embossing method, and print foaming method,
No. 109450 discloses that a shielding plate having through-holes punched out with an appropriate pattern is used, and a coating layer of polyvinyl chloride resin containing a foaming agent is irradiated with infrared rays through the through-holes. A method of forming an embossed pattern by foaming only the resin portion is also known. However, since the latter method uses polyvinyl chloride resin, it requires a high temperature of over 200°C and an irradiation time of 80 to 100 seconds to foam, so in reality, the speed must be slowed down considerably, or In addition to the problem that the shielding plate had to be long, it was also necessary to provide a distance between the shielding plate and the resin layer that would not inhibit foaming, so the sharpness of the uneven pattern obtained was somewhat affected. There was a flaw in it.

In view of the above-mentioned drawbacks, the present invention is similar to the prior art described above in that infrared rays are irradiated through a punched plate exhibiting an appropriate pattern, but a polyolefin resin with a low thermal melting temperature and high shrinkage is used. They differ in that a foam sheet is used and that the portion is melted and shrunk by infrared irradiation to form a recess.

Unlike non-foamed sheets, it is easy to melt and shrink the infrared irradiated portions of the foamed sheet to form recesses there. This foam sheet is also a lined product,
The foam sheet may not be lined, or the surface of the foam sheet may be buffed or appropriately printed, if desired.

The punched plate exhibiting a figure corresponding to the desired pattern may be made of aluminum foil, aluminum plate, asbestos paper, or a metal plate plated with silver or chrome, which have a remarkable shielding effect against infrared rays. If the punching board itself is heated to around 80℃ by irradiation with infrared rays, it is not possible to touch the foam sheet to the shielding board, or to
However, if the above-mentioned material is used, the effect of infrared rays on the punched plate is very small due to the short melting time. This punching board does not need to be connected if it is a batch type, but
When used continuously, connect endlessly by appropriate means.

The irradiation conditions using the infrared heater may be set so that the surface temperature is slightly higher than the melting temperature of the foam sheet material. At this time, the size and shape of the pattern are not affected much.

To describe the effects of the present invention, firstly, melting due to infrared irradiation occurs in an extremely short time, and the surface of the recesses formed by melting and shrinking changes to a glossy flat surface, so that the foam sheet can be buffed. If it is a product, the appearance will be markedly different from that of a fluffy convex part, and the design effect will be outstanding.

Secondly, since the recesses are formed by melting and shrinking the portion of the foam sheet that has been irradiated with infrared rays, even if a punching plate is placed on the foam sheet surface and the sheet is in contact, the molten material will not reach the punching plate. The point is that even though they do not adhere and therefore are in direct contact, this does not pose any problem. The fact that the distance between the foam sheet and the punched plate can be made zero in this way means that the shape of the through hole punched out in the shielding plate is faithful to the shape, and the sharp uneven shape is exposed on the surface of the foam sheet. can be done. In addition, since the shielding plate may be brought into direct contact with the foam sheet surface, when ink is applied to the back of the shielding plate, this is placed on the foam sheet surface, and unevenness is formed by infrared irradiation. The ink can be transferred to the convex surface of the unevenness, or conversely, the ink can be applied to the foam sheet portion that appears in the through-hole portion of the shielding plate, and then the portion is melted and shrunk by irradiation with infrared rays. If unevenness is formed, the same effect as the so-called valley staining method can be easily obtained.

Third, as the shielding plate is gradually separated from the foam sheet surface, the sharpness of the unevenness formed on the foam sheet surface gradually disappears, making it possible to form a blurred uneven pattern shape. Furthermore, the depth of the obtained unevenness can be changed as appropriate by changing the amount of heat provided by the infrared heater, changing the capacity of the infrared heater, changing the mounting height, and changing the irradiation time.

As described above, the present invention has many advantages as a method for manufacturing a decorative sheet having an uneven pattern.

Examples are given below.

A punching board 1 made of an aluminum plate and exhibiting a punching pattern as shown in FIG. 1, and a foamed polyethylene sheet 2 whose surface has been buffed as shown in FIG. 2 are prepared, and the punching board is placed on the foamed sheet. Put it on,
When irradiated with infrared rays for 5 seconds using an 800W infrared heater placed 50mm above the punched plate, as shown in Figure 3, the surface 3 of the recess formed by melting and shrinking became a glossy flat surface and was buffed. Correspondingly, a product with an interesting contrast can be obtained, as the surface 4 of the convexity gives a soft feel.

Note that it is preferable to use far infrared rays, which have a large heating effect, as the infrared rays used in the present invention.

[Brief explanation of the drawing]

Figure 1 shows one side of a punched plate used in the method of the present invention, Figure 2 shows an example of a foam sheet made of polyolefin synthetic resin, and Figure 3 shows a product obtained by the method of the present invention. FIG. DESCRIPTION OF SYMBOLS 1... Punching board, 2... Foamed sheet, 3... Recessed part surface, 4... Convex part surface.

Claims (1)

[Claims] 1. A punched plate exhibiting a desired pattern is placed in contact with a polyolefin synthetic resin foam sheet or kept at a slight distance, and infrared rays are irradiated from above the punched plate. A method for producing a sheet-like article having an uneven pattern, characterized in that the portion of the foamed sheet not covered by the punching plate is melted and shrunk to form an uneven pattern corresponding to the pattern of the punching plate. 2. The method for producing a sheet-like article having an uneven pattern according to claim 1, wherein the surface of the foamed sheet is fluffed by buffing.