JP6721286B2 - Packaging material - Google Patents

Description

The present invention relates to packaging materials.

2. Description of the Related Art Conventionally, there is a packaging material obtained by printing a printing ink on a paper base material such as a printing paper, and various containers and the like are manufactured using the packaging material.

In such a packaging material, for the purpose of improving its designability, for example, as disclosed in Patent Document 1, a printing layer is provided with glossiness.

JP 2003-2322 A

However, there is a case where a desired glossiness cannot be obtained by simply providing a printing layer having gloss on the base material depending on the state of the base material as the base. Further, depending on the desired design, there is a case where the printing layer is provided only on a specific portion, not on the entire surface of the substrate, and in such a case, the designability of the portion where the printing layer is not provided is a problem. Sometimes it was.

On the other hand, a packaging material in which a film having gloss is attached to a base material has also been proposed. However, in this case, there is a possibility that curling may occur due to the bonding, which may result in poor accuracy when forming a container or the like, or a decrease in manufacturing yield.

The present invention has been made under such circumstances, and a main object of the present invention is to provide a packaging material having higher glossiness without causing a problem of curling.

The present invention for solving the above problems is a packaging material in which an ionizing radiation curable resin layer and a gloss printing layer are sequentially laminated on a substrate, and the gloss printing layer is at least a binder resin. And a thin metal piece having a thickness of 0.01 to 0.08 μm, and the specularity of the surface of the ionizing radiation-curable resin layer on the side where the glossy printing layer is laminated is 85% in a measurement based on JIS Z8741. The above is the feature.

In the above invention, the surface roughness PPS of the surface of the ionizing radiation curable resin layer on the side where the glossy printing layer is laminated may be less than 1 μm in the measurement based on JIS P8151.

In the above invention, the base material may be paper, and the glossiness at an angle of 60° of the glossy printing layer may be 200 or more in the measurement based on JIS Z8741.

According to the present invention, since the layer that imparts gloss is formed by printing, curling can be suppressed. In addition, since the ionizing radiation-curable resin layer is arranged in the portion that becomes the base of the glossy print layer and the specularity of the surface is strictly limited, the glossiness of the glossy print layer can be dramatically improved. In addition, it is possible to improve the designability of the portion where the glossy print layer is not formed. In addition, since the glossy printed layer uses metal flakes instead of metal particles, a desired glossiness can be obtained.

It is a schematic sectional drawing of the packaging material of this embodiment. It is a schematic sectional drawing of the packaging material of another embodiment of this invention. It is a development view of a packaging container using the packaging material of this embodiment.

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

FIG. 1 is a schematic cross-sectional view of the packaging material of this embodiment.

As shown in FIG. 1, the packaging material 10 according to the present embodiment comprises a base material 11 on which an ionizing radiation-curable resin layer 12 and a glossy printing layer 13 are sequentially laminated. Each layer constituting the packaging material 10 will be described below.

(Base material)
The base material 11 serves as a base portion for laminating the ionizing radiation curable resin layer 12 and the gloss print layer 13 thereon. The material of the base material 11 is not particularly limited as long as it is a material that has been conventionally used for printed matter and the like. Specifically, high-quality paper, medium-quality paper, coated paper, synthetic paper, impregnated paper, laminated paper, metal vapor deposition paper, printing coating paper, recording coating paper, polyethylene terephthalate film, polyethylene film, polypropylene film. , A plastic film such as a polycarbonate film, a metal foil, or a composite thereof. The material of the base material 11 can be appropriately selected depending on the strength required for the packaging material 10 and the intended use.

The thickness of the base material 11 is not particularly limited, and can be appropriately selected depending on the strength required for the packaging material 10, the application, and the like, like the material. Specifically, for example, in the case of employing paper as the base material may be a basis weight as ^{150g / m 2 ~550g / m 2} , in the case of adopting the plastic film as the substrate, 9Myuemu～25myuemu May be

(Ionizing radiation curable resin layer)
The ionizing radiation-curable resin layer 12 is a layer provided on the surface of the base material 11. In order to improve the glossiness of the gloss printing layer 13 provided thereon, and to improve the design of the packaging material as a whole. It is a layer provided.

Here, in the packaging material 10 according to the present embodiment, the surface of the ionizing radiation curable resin layer 12 on which the glossy printing layer 13 is laminated, that is, the specularity of the upper surface in FIG. 1 has JIS Z8741. It is characterized by being 85% or more in the measurement based on. By setting the specularity of the surface to 85% or more, the glossiness of the glossy printing layer 13 laminated thereon can be dramatically improved, and the designability of the portion where the glossy printing layer 13 is not laminated can be improved. Can also be improved.

If the specularity is 85% or more, the effect can be sufficiently exhibited, but 90% or more is more preferable, and 95% or more is particularly preferable.

The means for setting the specularity of the surface of the ionizing radiation-curable resin layer 12 to a desired value is not particularly limited, and it can be realized by devising the material selection, printing or coating method. ..

Here, in the ionizing radiation curable resin layer 12, in addition to the specularity, the surface roughness PPS of the surface on the side where the gloss print layer is laminated is less than 1 μm in the measurement based on JIS P8151. It is preferable that it is, and it is more preferable that it is 0.6 μm or less. By setting the surface roughness PPS of the surface to be less than 1 μm, the above-mentioned effects can be more remarkably exhibited.

The means for setting the surface roughness PPS of the ionizing radiation-curable resin layer 12 to a desired value is not particularly limited, and it can be realized by devising the material selection, printing or coating method. ..

Such a material for the ionizing radiation curable resin layer 12 is a UV curable resin which is cured by irradiating a conventionally known UV ray under the condition that the specularity is 85% or more, or Any conventionally known electron beam-curable resin that has been cured by irradiation with an electron beam can be appropriately selected and used. Further, the resin used as the material of the ionizing radiation curable resin layer 12 is preferably colorless and transparent or colored and transparent. This is because if it is transparent, ultraviolet rays and electron beams can be well transmitted to the back surface side of the ionizing radiation curable resin layer 12, that is, the base material 11 side, and it is easier to cure. This is because if it is colorless and transparent, a desired design can be exhibited without interfering with the color development by the glossy print layer 13.

Examples of the ionizing radiation curable resin include an ultraviolet curable resin and an electron beam curable resin. Examples of the ultraviolet curable resin include a polyfunctional acrylate having two or more functional groups, a polyfunctional acrylate having two or more functional groups, and a polyfunctional methacrylate having two or more functional groups.

The thickness of the ionizing radiation curable resin layer 12 is not particularly limited and can be appropriately designed. Specifically, for example, it may be 4 μm to 8 μm.

In the embodiment shown in FIG. 1, the ionizing radiation curable resin layer 12 is provided on the entire surface of the base material 11, but it is not necessarily provided on the entire surface, and at least at the position where the glossy printing layer 113 is provided. It may be provided at the corresponding position.

(Glossy print layer)
The gloss print layer 13 is a layer provided by printing on the ionizing radiation curable resin layer 12 having the desired specularity, and at least a binder resin 13a and a metal having a thickness of 0.01 to 0.08 μm. It is characterized by including a thin piece 13b.

As described above, by forming the layer that imparts gloss to the layer formed by “printing”, it is possible to suppress the occurrence of curling. Further, by using not the metal particles but the metal flakes 13b having a predetermined thickness as the gloss source for expressing the gloss, the metal flakes are uniformly arranged in parallel with the surface of the gloss print layer, and The specularity of the surface of the ionizing radiation-curable resin layer 12 is set to a predetermined value, so that the glossiness can be dramatically improved.

A known binder resin can be used as the binder resin 13a. Specific examples include polyester resin, urethane resin, epoxy resin, melamine resin, alkyd resin, phenol resin, acrylic resin and the like. Alternatively, an ionizing radiation curable resin may be used as the binder resin 13a. As the ionizing radiation curable resin, the same material as the above-mentioned ionizing radiation curable resin layer 12 can be used.

Here, the binder resin 13a may contain a solvent. When the binder resin 13a contains a solvent, when the solvent is volatilized and the binder resin 13a is cured, the thin metal pieces 13b contained in the binder resin 13a are floated on the surface and arranged in parallel uniformly. Because you can build up. The solvent is not particularly limited and can be appropriately selected and used from various conventionally known solvents.

As the material of the metal thin piece 13b, various metals and alloys such as aluminum, gold, silver, brass, titanium, chromium, nickel, nickel chromium, and stainless can be appropriately selected and used. The thickness of the metal thin piece 13b is 0.01 to 0.08 μm. If the thickness is less than 0.01 μm, it may be difficult to handle or the desired gloss may not be exhibited. On the other hand, when the thickness is more than 0.08 μm, it becomes difficult to form a state in which the surfaces are uniformly arranged in parallel, and as a result, desired gloss may not be exhibited. Further, the length of the metal thin piece 13b in the surface direction can be set to 5 to 15 μm.

The mixing ratio of the binder resin 13a and the metal flakes 13b is preferably 55:45 to 35:65, and more preferably 50:50 to 40:60 in terms of solid content mass ratio. When the binder resin 13a is more than 55% by mass, it becomes difficult to obtain a desired glossiness, and when the metal thin piece 13b is more than 65% by mass, the adhesion of the glossy printing layer to the ionizing radiation curable resin layer is likely to be lowered. , Post-processing suitability may become worse.

The glossy printing layer 13 may contain, for example, various colorants in addition to the binder resin 13a and the metal flakes 13b. By containing a colorant, the glossy printed layer can be made into a desired color. As the colorant, a known colorant can be used, and examples thereof include titanium oxide, zinc white, carbon black, iron oxide, iron yellow, ultramarine blue, metallic pigments and pearl pigments.

The method for forming the glossy printing layer 13 is not particularly limited, and various printing methods such as a gravure printing method and a relief printing method can be used.

Further, as shown in FIG. 1, the glossy printed layer 13 does not need to be provided on the entire surface of the ionizing radiation curable resin layer 12 as a base, and may be formed in a pattern according to a desired design. Good.

The coated amount of the glossy printed layer 13 after drying is preferably 0.5 g/m ² or more and less than 2 g/m ² . If it is out of this range, the desired glossiness cannot be obtained, which is not preferable.

According to the packaging material of the embodiment of the present invention, even when paper is used as the base material, for example, the glossiness at an angle of 60° according to JIS Z8741 can be 200 or more, and excellent glossiness can be obtained. Degree can be realized.

FIG. 2 is a schematic sectional view of a packaging material according to another embodiment of the present invention.

As shown in FIG. 2, the packaging material 10 according to the present embodiment is shown in FIG. 1 in that an ionizing radiation curable resin layer 12 and a gloss print layer 13 are sequentially laminated on a base material 11. This is the same as the embodiment, and further, the print display layer 14 and the overcoat layer 15 are provided on the ionizing radiation curable resin layer 12 or the gloss print layer 13. As described above, in the packaging material 10 according to the present embodiment, the print display layer 14 and the overcoat layer 15 may be provided. These will be described below.

(Printed display layer)
The print display layer 14 is a layer provided by printing on one or both of the ionizing radiation curable resin layer 12 and the gloss print layer 13. FIG. 2 shows an example in which the print display layer 14 is provided on both the ionizing radiation curable resin layer 12 and the glossy print layer 13. By providing the print display layer 14, the overall designability can be further improved.

The print display layer 14 may be provided in a desired pattern, as shown in FIG. 2, or may be provided on the entire surface (not shown). Specific examples of the print display include characters, figures, symbols, numbers, and various patterns.

(Overcoat layer)
As shown in FIG. 2, in the packaging material 10 according to the present embodiment, the overcoat layer 15 may be provided so as to cover the entire surface on the side opposite to the base material 11. By providing the overcoat layer 15, the entire surface can be protected.

The method for forming the overcoat layer 15 is not particularly limited, but may be formed by various printing methods, for example. The material of the overcoat layer 15 is also not particularly limited, but the same material as the thermosetting resin or the ionizing radiation curable resin layer 12 described above may be used.

FIG. 3 is a development view of a packaging container using the packaging material of the present embodiment.

As shown in FIG. 3, the packaging material according to the present embodiment can be used as a packaging container. In FIG. 3, the glossy print layer 13 is provided at the portion indicated by reference numeral 30. As described above, in the packaging material according to the present embodiment, since the gloss printing layer 13 can be provided by printing, it is possible to produce a packaging material having a partially excellent gloss at low cost.

(Example 1)
(1) A single-sided ivory paper having a basis weight of 235 g/m ² was prepared as a base material.
(2) Next, an ultraviolet curable resin (BASF Japan Lumogen OVD Primer301) as an ionizing radiation curable resin was applied to one surface of the base material by gravure printing so that the coating amount after drying was 6 g/m ² . By printing as described above and curing by irradiating with ultraviolet rays, an ionizing radiation curable resin layer was formed.
(3) The specularity of the surface of the ionizing radiation curable resin layer was 87 in the measurement based on JIS Z8741, and the surface roughness PPS of the surface was 0.6 μm in the measurement based on JIS P8151.
(4) Next, a printing ink having the following composition 1 and containing a solvent is printed on the surface of the ionizing radiation-curable resin layer by gravure printing so that the coating amount after drying is 1 g/m ^2. The packaging material of Example 1 was obtained.
(Composition of printing ink 1)
Binder resin (nitrified cotton: DIC Graphics XS-763 Medium NT-No. 1): 40 parts by mass Aluminum thin piece: 60 parts by mass Aluminum thin piece thickness: 0.01 to 0.08 μm
The thickness of the aluminum flakes was measured by Hitachi Scanning Electron Microscope SU3500.

(Example 2)
A packaging material of Example 2 was obtained under the same conditions as in Example 1, except that the gravure plate for printing the ultraviolet curable resin was changed.

(Example 3)
A packaging material of Example 3 was obtained under the same conditions as in Example 1 except that the base material in Example 1 was OK balls.

(Comparative Example 1)
A packaging material of Comparative Example 1 was obtained under the same conditions as in Example 1 except that the gravure plate for printing the ultraviolet curable resin was changed.

(Comparative example 2)
(1) A single-sided ivory paper having a basis weight of 215 g/m ² was prepared as a base material.
(2) Further, a biaxially stretched PET film having a thickness of 12 μm provided with a 500 Å aluminum vapor deposition film was prepared.
(3) Then, the one-sided ivory paper and the one-sided ivory paper are extruded with polyethylene by the sand laminating method while facing the surfaces of the biaxially stretched PET film provided with the evaporated film of aluminum on the side not provided with the evaporated film The packaging material of Comparative Example 2 was obtained by laminating it with a biaxially stretched PET film provided with an aluminum vapor deposition film.

(Comparative example 3)
A packaging material of Comparative Example 3 was obtained under the same conditions as in Example 1 except that the ionizing radiation-curable resin layer in Example 1 was not provided.

(Evaluation)
For each of the packaging materials of Examples 1 to 3 and Comparative Examples 1 to 3, the glossiness of the surface of the glossy printed layer and the curling degree of the packaging material were evaluated.

The glossiness was evaluated based on JIS Z8741. In addition, the evaluation of the curl condition is made in JAPAN TAPPI No. Based on No. 15-1, it was performed under the conditions of a temperature of 25 degrees and a humidity of 75% RH.

Examples 1 to 3 and Comparative Examples 1 to 3, main constitutions of the respective packaging materials and the above evaluation results are summarized in Table 1 below.

From the above results, it was found that the packaging materials of Examples 1 to 3 of the present invention had no curl and had excellent glossiness.

Claims (4)

A packaging material in which an ionizing radiation curable resin layer and a metallic glossy printing layer are sequentially laminated on a paper substrate,
The ionizing radiation curable resin layer is a single layer and has a thickness of 4 to 8 μm,
The metallic glossy printing layer comprises at least a printing ink containing a binder resin, a thin metal piece having a thickness of 0.01 to 0.08 μm, and a solvent (provided that “oxidation polymerization type printing ink and ultraviolet curing type printing ink are used. (Excluding "," is printed and dried, so that the thin metal flakes are floated on the surface and are uniformly arranged in parallel on the surface.
The metallic gloss print layer is provided in a pattern,
A print display layer is provided on the metallic gloss print layer,
The specularity of the surface of the ionizing radiation curable resin layer on the side on which the metallic glossy printing layer is laminated is 85% or more in the measurement based on JIS Z8741;
The ionizing radiation curable resin layer is provided at a position corresponding to at least the position where the metallic gloss print layer is provided,
A packaging material characterized by the following. The coating amount of the metallic glossy printed layer after drying is 0.5 g/m ² or more and less than 2 g/m ² .
The packaging material according to claim 1, wherein: The surface roughness PPS of the surface of the ionizing radiation curable resin layer on the side where the metallic glossy printing layer is laminated is less than 1 μm in the measurement based on JIS P8151.
The packaging material according to claim 1, wherein the packaging material is a packaging material. The base material is paper, and the glossiness at an angle of 60° of the metallic glossy printed layer is 200 or more in a measurement based on JIS Z8741. Packaging material.

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