JPS6023993B2 - How to form a crack pattern - Google Patents

Description

Detailed Description of the Invention The present invention provides a heat shrinkable film with a partial heat absorption difference to generate cracks due to the heat shrinkage difference, thereby revealing the color of the underlying synthetic resin layer from between the cracks. The present invention relates to a method for forming a new crack pattern.

Generally, even if various patterns are printed on a synthetic resin film or sheet, the texture of the material will not change much.

Creating a metallic luster through vacuum deposition of metal is the most effective way to change the material's appearance, but even if you add a decorative effect by printing, it will give a flat impression with no depth, and Furthermore, even if a tightening process is applied to this, the texture of the material will not change. If it were possible to express designs with different textures on the surface of the same synthetic resin, it would be possible to give the impression of a luxury product with high added value, and a method to do so is being developed. According to the present invention, the above features include a heat-shrinkable film layer, a reflective layer that reflects irradiated heat rays to prevent heat shrinkage in the film, and a reflective layer that absorbs irradiated heat rays to cause heat shrinkage in the film. Even if there are three layers, including a printing ink layer that draws an appropriate pattern or design that produces a pattern, the reflective layer is appropriately constructed on the thermoplastic resin layer so that the reflective layer is not on top, and the heat rays are irradiated from the printing ink layer side. This is achieved by creating cracks in the heat-shrinkable film portion and the reflective layer portion corresponding to the printing ink layer portion, and exposing the underlying thermoplastic resin layer from between the cracks. The present invention will be explained in detail below.

First, regarding the heat-shrinkable film, since the basic principle of the present invention is to cause cracks to appear due to shrinkage due to local heat absorption differences in the heat-shrinkable film, the film thickness of the heat-shrinkable film is determined by heat shrinkage. It must be capable of cracking, and generally such thickness is between 0.01 and 0.
．． It is about 5 sides. If it is too thick, it will cause cracks and become stiff, so it is not possible. Furthermore, as will be described later, in the present invention, since the purpose is to provide a difference in shrinkability based on the difference in endotherm between reflection and absorption of heat rays, it is desirable that the heat-shrinkable film be transparent. However, as long as the coloring is sufficient to make it possible to recognize the presence of the reflective layer located below the heat-shrinkable film, there is no problem. As a means for imparting a heat absorption difference to the heat-shrinkable film, the present invention relies on a reflective layer that reflects the irradiated heat rays and a printing ink layer that absorbs the irradiated heat rays.

The reflective layer is usually a vacuum-plated layer of aluminum, but it can also be formed by pasting metal foil or coating metal powder such as gold powder.The incident heat rays are reflected by this reflective layer, and the heat is It is possible to avoid applying heat that would cause shrinkage failure to the shrinkable film. The fact that the reflective layer is uniformly formed means that the reflection efficiency is excellent, and a beautiful crack pattern can be obtained. The reflective layer is formed on the heat-shrinkable film surface, and
There are two embodiments: a case where it is formed on the surface of the thermoplastic resin layer and a case where it is formed on the surface of the thermoplastic resin layer.

However, in any case, one of the aims of the present invention is that when cracks are generated in the heat-shrinkable film as described above,
The underlying thermoplastic resin is exposed through the cracks, making the crack pattern even more interesting. Therefore, the strength of the reflective layer, especially the strength of the metal foil when using metal foil, is determined by the heat-shrinkable film being cracked. When this happens, the metal foil must also be strong enough to cause cracks. Next, a desired pattern or design is applied using a printing ink with excellent heat absorption properties such as black pigment to form a printed part and a non-printed part, but by doing this, the printed part does not accumulate irradiated heat rays. In the end, the heat caused the heat-shrinkable film to shrink. On the other hand, in the non-printed areas, the heat-shrinkable film did not shrink due to the effect of the reflective layer described above. I can't close it.

In addition to being printed on the surface of the composite material, the printing that provides such an endothermic difference may be located in the middle of the composite material.
That is, if a reflective layer appears on the surface of the composite material, it is printed on the reflective layer, and the composite material is constructed in the following order: printed part - reflective layer - heat-shrinkable film - thermoplastic resin - base material. It turns out. In addition, when a heat-shrinkable film appears on the surface of the composite material, the heat-shrinkable film is printed on the surface, and therefore the order is printed part - heat-shrinkable film - reflective layer - thermoplastic resin - base material. In addition, printing may be done by brush-printing on the heat-shrinkable film, or it may be printed on the surface of the reflective layer located under the heat-shrinkable film, which has the same effect as this back printing.In this case, the heat-shrinkable film The order is: - printed part - reflective layer - thermoplastic resin - base material. Printing can be performed by known methods such as gravure printing, offset printing, and screen printing. The important thing to get a beautiful crack pattern is to give a noticeable difference in heat absorption.The heating is done using infrared heaters, ceramic heaters, quartz tube heaters,
It is a method of directly irradiating the printing side with a hot ray such as a gas heater to provide rapid heating.

On the other hand, unless the material is heated rapidly, regardless of heat rays, a significant difference in endothermic heat absorption will not be provided, and the formation of visible crack patterns will not be successful. The size of the resulting crack pattern can be adjusted by adjusting the intensity of heating with a hot wire, the thickness of the heat-shrinkable film, or moving the position of the cooling roll back and forth.

Furthermore, by printing with a pigment that has high heat absorption and printing with a pigment that is not so high at the same printing location, a difference in cracks occurs and a complex texture can be obtained. Incidentally, in order to increase the commercial value, it is possible to emboss it by an appropriate means. What is particularly noteworthy about the product obtained by the method of the present invention is that the printed area has a clear outline, as if it were greened, in the 1 to 1 mounds around the printed area that forms the border with the non-printed area. The above-mentioned crack pattern is intricately formed on the inside of the printed area.

The reason why such a wonderful outline is formed is thought to be as follows. When the temperature in the printed area rises and the shrinkage force exerted by the heat-shrinkable film in that area becomes stronger than the adhesive force with the thermoplastic resin layer, the tensile strength that pulls the area around the printed area toward the non-printed area increases. It is thought that this is because the shrinkage force in the center of the printed area is stronger than the shrinkage force in the center of the printed area, and therefore cracks occur in the center of the printed area, but the contour areas remain as they are without cracking. Examples are shown below.

Example 1 Please refer to the cross-sectional views shown in FIGS. 1 and 2.

A paste-like paint made of polyvinyl chloride resin having the following composition was applied onto the base material paper 1 using a doctor knife coater to a thickness of 0.1 mm, thereby preparing a material on which a thermoplastic resin layer 2 was formed. . Paste paint composition
(Parts by weight) Polychlorinated pinyl resin 1
0 eaves dioctyl phthalate (D-〇.P) Isobe titanium oxide 1 anchor part azodicarbonamide 1 part Cd-Ba stabilizer
2 parts, while 0.015 skin polyester film which is a heat shrinkable film with residual strain 4
A material with a reflective layer 3 formed by vacuum evaporating aluminum on one side is prepared, a PVC/acrylic adhesive is applied to the reflective layer 3 surface, and the material is applied with a 15,000 hot roll at a pressure of 5 kg/ground. Two thermoplastic resin layers of the above materials were closely bonded together to form a composite material.

Next, a printed portion 5 was formed on this heat-shrinkable film 4 by gravure printing on the frame portion of the tile-like pattern using a printing ink having the following composition. Therefore, the order is printing part - heat shrinkable film - reflective layer - thermoplastic resin - base material. Ink composition (weight%) Polyester resin 15% Carbon black 20% Solvent
65% After preheating this printed matter in a 10,000 steam drum, using a quartz tube heater,
After rapid heating at 250° C. for 5 seconds, a texture pattern was embossed through a shark roll.

The obtained product is shown in Photo 1, and its cross-sectional view is shown in FIG. 5' is a state in which the printed portion 5 has cracked.

As is clear from Photo 1, the printed area 5' has a cracked pattern, like a net, and the white vinyl chloride resin layer 2 is exposed from the gaps, and the area around the printed area 5' is like a net. The black outline remains on the ~3 ribs, and the reflective layer 3 with metallic luster gives a hard feel to the non-printed parts, and when viewed as a whole, it looks as if a metal plate has been pasted on that part. The design was obtained.

On the other hand, Photo 2 shows a product that was heated slowly, and it is clear that no cracks were formed at all. Example 2 A polyvinyl chloride resin compound of the following composition was rolled on a calendar roll to make a 0.2 skin-thick light brown colored vinyl chloride sheet, and a woven fabric (
It was pasted on the paper.

Polyvinyl chloride resin compound composition (parts by weight) Polyvinyl chloride resin 10 capitals dioctyl phthalate (D-〇.P) 7 parts titanium oxide
Part 15 Bengara
5 parts carbonic acid or resin 3 parts Cd-Ba stabilizer 2 parts Meanwhile,
A polyester film, which is a heat-shrinkable film with a thickness of 0.015 mm, is dyed a light clear color, aluminum is vacuum-deposited on one side, and carbon black and Bengara are coated with a polyamide-based vehicle on the vapor-deposited side. , a tree trunk-like print was created using a dark brown printing ink using yellow lead pigment.

Then, the polyester film surface was laminated onto the vinyl chloride sheet described above using a vinyl chloride/acrylic adhesive. Therefore, the order is printing part - reflective layer - heat shrinkable film - thermoplastic resin - base material. When this printed material was subjected to the heat treatment described in Example 1 and then cooled with a flat roll, the printed portion of the obtained product was found to be a light brown polyvinyl chloride layer with silk-like cracks. Approximately half of the resin layer is exposed in the printed area, and the border with the non-printed area is clearly bordered by a dark brown outline on the 2nd and 3rd sides, giving the appearance of the solid skin of a tree. Furthermore, the non-printed areas had a golden mirror surface, giving the overall impression of a mural. Example 3 A paste-like paint made of the same polyvinyl chloride resin as in Example 1 was applied onto paper as a base material to a thickness of 0.2 cm.
A material coated with a doctor knife coater was prepared, and on the other hand, a polyester film on the 0.015 side, which was a heat-shrinkable film with no residual strain, was printed with stripes at 3-segment intervals using ink with the same composition as in Example 1. A material with a reflective layer was prepared by printing on the entire surface with an ink having the following composition in which aluminum powder was mixed on top of the stripe printing.

The polyvinyl chloride resin surface of the material having the polyvinyl chloride resin layer and the reflective surface described below were closely bonded together using a vinyl chloride/acrylic adhesive.

Therefore, the composition of the composite material is in the following order: heat-shrinkable film - printed part - reflective layer - thermoplastic resin layer - base material.
Ink composition (weight%) Polyester resin 20% aluminum powder
15% solvent
65% This printed material was subjected to the heat treatment described in Example 1 and then passed through a sand-grained shark roll for embossing.

The resulting product had a wonderful crack pattern in the printed area, and the product as a whole resembled a metal plate.

[Brief explanation of drawings]

FIGS. 1 and 2 are explanatory diagrams to facilitate understanding of the method of the present invention. DESCRIPTION OF SYMBOLS 1... Base material, 2... Thermoplastic resin layer, 3... Reflective layer, 4... Heat-shrinkable film, 5... Printing part. Figure 1 Figure 2

Claims (1)

[Claims] 1. A heat-shrinkable film layer, a reflective layer that reflects irradiated heat rays and prevents the film from causing heat shrinkage, and printing with an appropriate pattern or design that absorbs irradiated heat rays and causes heat shrinkage on the film. Even if there are three layers including the ink layer, the reflective layer is appropriately constructed on the thermoplastic resin layer so that it is not on top, and heat shrinkage that hits the printing ink layer portion is achieved by irradiating heat rays from the printing ink layer side. At the same time, the heat-shrinkable film portion that is in contact with the printing ink layer portion is heated rapidly, and the heat-shrinkable film portion that is in contact with the printing ink layer portion is heated rapidly. A crack characterized by causing cracks in the film portion and the reflective layer portion of the film portion due to rapid thermal contraction accompanying heating, and exposing the underlying thermoplastic resin layer from between the cracks. How the pattern is formed.