JP2983251B2 - Decorative sheet - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a decorative sheet, and more particularly, to a decorative sheet provided with different kinds of uneven patterns made of ionizing radiation-curable resin in synchronization.

[Prior Art] Among various decorative sheets, there is known a decorative sheet in which a desired uneven pattern (shape) is appropriately applied to a sheet substrate in order to obtain a decorative appearance having a better design.

As this kind of decorative sheet, a printing ink layer with a feeling of unevenness is formed by a screen printing method that can form a relatively thick coating film, and after UV curable resin ink is raised and printed, it is cured by UV irradiation It is mainly known that a cured resin layer with a feeling of unevenness is formed, an unnecessary layer portion is removed by a chemical embossing method to make an uneven surface, and an uneven shape is formed by a heating embossing method. ing.

[Problems to be solved by the invention]

However, any of the decorative sheets (1) to (4) above does not form an uneven pattern having a sharp and desired uneven shape (surface), and particularly does not form a fine uneven pattern. A satisfactory appearance was not obtained.

Above all, in the case of the above decorative sheet, there is a problem that a sharp and fine uneven shape cannot be obtained because the liquid ink flows before the ultraviolet irradiation and the coating film collapses. In the case of the decorative sheet described above, since a sheet material of a thermoplastic material is used, several μm
There is a drawback that unevenness such as grain return of m to several tens of μm occurs and lacks sharpness, and in particular, it is impossible to form a fine unevenness such as 10 μm or less. Some of the decorative sheets described above are formed by synchronizing different types of embossed concavities and convexities with different concavo-convex shape patterns on both surfaces of the sheet substrate in order to bring out a cosmetic appearance excellent in three-dimensional appearance. However, in the case of the double-sided embossed decorative sheet, there is a defect that the irregular shape initially formed is deformed or disappears due to heat during processing, and since the base material shrinks due to heating during processing, the front and back surfaces are reduced. The embossed irregularities cannot be accurately synchronized with each other to form and form. As a result, a cosmetic appearance with a three-dimensional appearance and rich in design was not obtained.

The present invention has been made to overcome the above-mentioned drawbacks of the prior art, and provides a decorative sheet capable of obtaining a highly decorative cosmetic appearance in which different types of uneven patterns having sharp and precise shapes are formed in synchronization. The purpose is to:

[Means for solving the problem]

That is, the decorative sheet of the present invention is a decorative sheet in which a plurality of types of uneven patterns having different colors or / and formed patterns are provided in synchronism with each other on the same surface or opposite front and back surfaces of the sheet substrate, Each of the concavo-convex patterns is formed of an ionizing radiation-curable resin which is release-molded after being brought into close contact with the substrate side at the same time as curing and shaping at least in the plate recesses of the roll intaglio for contacting the sheet substrate. In the pattern.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. The decorative sheet 1 of the present invention is composed of a sheet substrate 2 and different concavo-convex patterns 3a and 3b provided on the substrate 2 with different colors or formed patterns or different colors and formed patterns. The formation pattern refers to the type of uneven shape in the uneven pattern, the type of planar shape of the pattern, and the like. Different types of uneven patterns 3a and 3b may be provided on the same surface of the substrate 2 as illustrated in the figure, or may be separately provided on each of the front and back surfaces of the substrate 2 as shown in FIG. In addition, heterogeneous uneven patterns 3a, 3b
They are provided in synchronization with each other. The above-mentioned “tune” means a state in which different types of uneven patterns are always accurately formed while maintaining a predetermined positional relationship, and a state in which different types of uneven patterns are all formed at the same position. It does not mean to be limited. Further uneven patterns are 2
It is not limited to the type, and a plurality of different types may be used.

The sheet substrate 2 is not particularly limited as long as it has strength and flexibility that can be processed on a web used as a raw material for printing or decorative sheets. The substrate 2 may be opaque when different types of uneven patterns are provided on the same surface of the substrate, but are located on the back side when different types of uneven patterns are separately provided on the front and back surfaces of the substrate. It is necessary to use a transparent base material so that the uneven pattern can be seen through. In the case of a sheet base material having transparency, the base material may be colored or matted as long as the transparency can be maintained. Specific examples of the base material include polyesters such as polyethylene terephthalate, polyamides such as nylon, polyvinyl chloride, acrylic resins such as polymethyl methacrylate, polycarbonate, polystyrene, polyacrylate, and fluororesins.
Sheets and films made of synthetic resins such as polypropylene, cellulose triacetate, and cellophane, as well as papers such as thin paper and woodfree paper, and those made of metal foil such as aluminum and copper, etc., are used alone. Alternatively, they may be appropriately combined and used as a laminated composite.

Regardless of the type of the uneven pattern 3 (a, b) in the present invention, any of the uneven patterns to be formed is filled into a roll intaglio in which the uneven shape to be formed is molded, and is cured during the filling to reduce the unevenness of the intaglio. It is a pattern made of an ionizing radiation-curable resin formed into a corresponding uneven shape, and is basically formed in common by the following forming method. That is, for example, the sheet base material 2 is supplied so as to be in contact with the roll intaglio 4 installed as shown in FIG. 3, and at least the plate concave portion 5 of the intaglio 4 is filled with the ionizing radiation-curable resin 6 by appropriate means. While the substrate 2 is in contact with the intaglio 4, the resin interposed between the substrate and the intaglio is irradiated with ionizing radiation by the ionizing radiation irradiating device 7 to cure and mold the resin, and at the same time, adheres to the substrate. At least after that, the substrate 2 is peeled off from the intaglio 4 to form the uneven pattern 3 on one surface of the substrate.
In the present invention, since the above-described method is employed for forming the uneven pattern, an uneven pattern having an extremely clear uneven shape that faithfully reproduces the uneven shape molded into the roll intaglio can be obtained. Very good patterns can be obtained even if the pattern has a rough uneven shape.

In the case where the uneven pattern 3 having a different color is provided, a resin colored in a different color may be used as the ionizing radiation-curable resin. In addition, the uneven pattern 3 having a different formation pattern
Is provided, a required number of roll intaglios having different concave and convex shapes may be used. In the case where the concavo-convex pattern 3 having a different color and a different shape pattern is provided, an ionizing radiation-curable resin of a different color and a roll intaglio of a different kind may be appropriately used as described above.

In actually forming different kinds of uneven patterns, different kinds of uneven patterns are continuously formed on the same manufacturing line or individually formed on separate manufacturing lines according to the above-mentioned common basic uneven pattern forming method. Can be formed. However, it is desirable to form them on the same manufacturing line from the viewpoint of good manufacturing efficiency and further improving the synchronization accuracy between different types of uneven patterns. In the case of forming on the same production line, for example, a required number of concave and convex pattern forming process units (devices) as illustrated in FIG.
A differently colored ionizing radiation-curable resin is appropriately selected and used as the ionizing radiation-curable resin 6 after the step, or a different intaglio roll intaglio is used as the roll intaglio 4 in the second and subsequent steps. By appropriately selecting and using, different types of uneven patterns can be continuously and efficiently formed. In order to form the concavo-convex pattern in the first step and the concavo-convex pattern in the second and subsequent steps in synchronization with each other, a so-called “register” technique usually used in multicolor printing is applied. Good.

As the ionizing radiation-curable resin for forming the concavo-convex pattern, a known ultraviolet or electron beam-curable resin can be used. Among them, the use of a solvent-free type resin causes problems such as volume shrinkage due to curing, shape deformation, and bubble generation. This eliminates the need for a pre-drying step of the resin, and makes it easier to reliably obtain an uneven shape with better reproducibility. As a coloring agent for coloring the ionizing radiation-curable resin, a known coloring agent can be used, but the ionizing radiation irradiated to cure the resin is absorbed as much as possible, thereby causing a curing reaction of the resin. Are preferred.

When irradiation with ionizing radiation is performed from the sheet substrate 2 side as illustrated in FIG. 3, the substrate needs to be ionizing radiation-permeable. In the case where the roll intaglio 7 is formed of a transparent material such as glass, the irradiation can be performed by an irradiation device installed inside the intaglio. In particular, when different types of uneven patterns are provided on the same surface side of the opaque sheet substrate 2, it is necessary to select and use an electron beam that can pass through the substrate. Although it varies depending on the thickness and the material of the material, it is usually about 0.5 to 30 Mrad. The degree of curing of the resin by the irradiation with ionizing radiation may be basically such that the resin loses at least the fluidity and causes adhesion to the sheet substrate. However, in the case where different types of uneven patterns 3 overlap each other, the adhesiveness between the resins forming the overlapping uneven patterns tends to be deteriorated. It is desirable to appropriately adjust the degree of curing so that the resin is completely cured by irradiation of the uneven pattern formed later.

When forming different types of uneven patterns, the plate depth should be 0.1 to 1
In the case where different roll intaglios 7 are used within the range of 000 μm, the roll intaglios having the shallower plate depths are used sequentially (in other words, the height of the uneven shape is lower) in the previous step. This is desirable because there is little possibility that the formation of the concavo-convex pattern in a post-process performed on a portion such as a concave portion of the formed concavo-convex pattern is reduced. However, the manufacturing procedure is not limited to the above-mentioned plate depth, and the plate may be formed in order from the deeper one depending on the design. The uneven pattern 3 may be in the form of a pattern separated from each other as shown in FIGS. 1 and 2, but may be in the form of a layer (not shown) covering the entire surface of the substrate 2 (for example, a base layer portion). (A shape in which a convex portion and a concave portion are formed on the entire surface).

The decorative sheet of the present invention as described above can be used as a decorative material in various fields. Among them, those using a laminated base material in which a metal layer such as aluminum is provided on paper such as high-quality paper or thin paper as a sheet base material are particularly suitable as packaging materials for cigarettes, confectionery and the like. A sheet material made of a thermoplastic resin such as ABS or polyvinyl chloride is used at the same time as molding and processing such as injection molding, vacuum molding, extrusion molding, lapping, etc. It is suitable as a surface decorative material to be used by bonding to the surface.

Next, the present invention will be described in more detail with reference to specific examples.

Example 1 A transparent polyvinyl chloride film having a thickness of 0.1 mm (manufactured by Riken Vinyl Co., Ltd .: W-500, 23P) was used as a sheet substrate, and the configuration of the uneven pattern forming step shown in FIG. The production line was used to produce a decorative sheet. That is, a UV curable resin (manufactured by Dainichi Seika Co., Ltd .: Seika Beam EX880926, viscosity 3000 cps / 25 ° C.) was applied to cyanine blue and a monoazo quinacridone pigment on a first roll intaglio for forming a grain pattern on one side of the film. Was formed to form a first concave-convex pattern composed of a resin composition.

Next, on the same surface of the film, a second concavo-convex pattern made of a resin composition in which the pigment is appropriately blended with the ionizing radiation-curable resin is applied to the first concavo-convex pattern using a second roll intaglio for forming a wood grain concavo-convex pattern. A decorative sheet was formed while synchronizing with the pattern.

The ultraviolet irradiation for curing each of the above resin compositions was performed at the time of forming the first uneven pattern by using an ozone-containing high-pressure mercury lamp (80 W /
cm) with a sheet feed speed of 30m /
The conditions were the same as those described above except that two high-pressure mercury lamps having a strength of 160 W / cm were used when the second uneven pattern was formed. As a result, it was confirmed that the cured resin was well adhered to each other at the portion where the two uneven patterns overlapped each other.

In the obtained decorative sheet, the first and second concave and convex patterns are sharply and precisely formed, and both are formed precisely in synchronization without positional deviation, and the two concave and convex patterns are perfectly harmonized. It was excellent in three-dimensional appearance, and exhibited a real wood grain design and unevenness. In addition, since the sheet surface was covered with an uneven pattern film made of a cured ultraviolet curable resin, the surface properties were excellent.

[Effects of the Invention] As described above, the decorative sheet of the present invention has a plurality of concavo-convex patterns different in color and / or formation pattern and formed in synchronization with each other as described above, and all of the concavo-convex patterns are roll intaglio. Since it is a pattern of the uneven shape of the ionizing radiation curable resin formed by curing and shaping inside, all the uneven patterns are sharp and precise, and the different uneven patterns are synchronized very accurately And as a result,
Different types of uneven patterns are perfectly harmonized with each other, so that a cosmetic appearance having a particularly three-dimensional appearance and depth, and excellent color can be obtained.

In addition, according to the present invention, since a high-temperature heating step such as a heating embossing method is not required in forming a concavo-convex pattern and a thermoplastic material is not necessarily used as a sheet substrate, different concavo-convex patterns are accurately synchronized and formed. It is possible to do. In addition, since all of the concave and convex patterns employ the above-described forming means, the excellent decorative sheet of the present invention as described above can be simply and efficiently structured. Furthermore, by forming the uneven pattern so as to cover one entire surface of the sheet substrate, there is an advantage that a decorative sheet having excellent surface properties such as heat resistance, scratch resistance, and solvent resistance can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of the decorative sheet of the present invention, FIG. 2 is a cross-sectional view showing another embodiment of the present sheet, and FIG. 3 is an example of a forming method for forming an uneven pattern. FIG. DESCRIPTION OF SYMBOLS 1 ... Decorative sheet, 2 ... Sheet base material 3 ... Uneven pattern (3a, 3b ... heterogeneous uneven pattern) 4 ... Roll intaglio, 5 ... Plate recess 6 ... Ionizing radiation curable resin

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshiaki Nezu 1-1-1 Ichigaya-Kaga-cho, Shinjuku-ku, Tokyo Inside Dai Nippon Printing Co., Ltd. (58) Field surveyed (Int.Cl. ⁶ , DB name) B32B 1/00-35/00 B44C 1/20

Claims (1)

(57) [Claims] 1. A decorative sheet comprising a plurality of types of uneven patterns having different colors and / or forming patterns provided in synchronism with each other on the same surface or on opposing front and back surfaces of a sheet base material. In any case, at least the inside of the intaglio plate of the roll intaglio to which the sheet substrate is brought into contact is a concave and convex pattern made of an ionizing radiation-curable resin that is release-formed after being brought into close contact with the substrate side at the same time as the molding. A decorative sheet, characterized in that: