JPH11348165A - Easy-cutting packaging material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To impart easy-cutting properties at the time of opening to a packaging material having gas barrier properties while holding necessary strength to the packaging material. SOLUTION: An easy-cutting packaging material 10A has a laminated structure of a gas barrier layer 13, a laser absorbing layer 12 and a film layer 11 and, while the laser absorbing layer 12 holds continuity without being cut by laser irradiation, the close adhesiveness with the layer (e.g.; gas barrier layer 13) coming into contact with the laser absorbing layer 12 at least at a part of the laser absorbing layer 12 is lowered or at least a part of the laser absorbing layer 12 is separated from the contact layer with the laser absorbing layer 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packaging material used for packaging foods and the like, and more particularly to a packaging material having an easy-to-cut property when opened.

[0002]

2. Description of the Related Art There have been proposed several methods for adding ease of opening to packaging materials. For example, it is known that a method of processing a broken line or a katakana character in the direction of opening, and that a notch or a flaw processing is performed to facilitate cutting out of the opening, and they are practically used. .

On the other hand, as a recent packaging material, a high-functional multilayer material having a gas barrier layer such as an aluminum layer or a ceramic layer as an intermediate layer has been used in order to provide a high barrier property against air and water vapor. In addition, as the packaging material including such a high-functional multilayer material, a material obtained by laminating a polymer material or the like on the surface layer is often used in order to impart sealing properties to itself.

[0004] As a method for imparting easy-openability to such a packaging material made of a high-functional multilayer material having a polymer material layer on the surface layer, as shown in FIG. , Aluminum layer 3, ink layer (heating layer)
2. A laminated material of the transparent polymer film 1 is irradiated with a laser beam having a wavelength of 0.4 to 1.2 μm to generate heat in the ink layer 2, and is adjacent to the ink layer 2 as shown in FIG. It has been proposed that the polymer film 1 to be melted and cut to form a kerf 4, thereby imparting a tear-opening property along the kerf 4 to the packaging material 10x (JP-A-8-183).
No. 133).

[0005]

However, FIG.
As shown in (b), the packaging material having the cut groove 4 formed thereon has a single layer of the aluminum layer 3 at the cut groove 4 portion, so that the packaging material has strength against surface printing, bag making, and the like generally applied to the packaging material. Was insufficient.

In order to solve such a problem, as shown in FIG. 6, it is conceivable to arrange material layers 5 and 6 which are not processed by transmitting a laser above and below the cut groove 4. However, with such a multilayer structure, there is a problem that the bending property of the packaging material is reduced and it is difficult to process the packaging material in a bag making process or the like.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a packaging material having a gas barrier property while maintaining the strength required for the packaging material and improving the ease of cutting at the time of opening. The purpose is to grant.

[0008]

Means for Solving the Problems In order to achieve the above object, the present inventors have sequentially laminated a gas barrier layer, a laser absorbing layer and a film layer, and the laser absorbing layer is cut by laser irradiation. Easy cutability, characterized in that at least a portion thereof has reduced adhesion to a layer in contact with the laser absorbing layer or has been peeled off from a layer in contact with the laser absorbing layer while maintaining continuity without Provide packaging materials.

In particular, the laser absorbing layer is made of red ink or the like, and at least a part thereof has a wavelength of 300 to 12
A mode in which the laser absorbing layer absorbs a laser of 00 nm, more preferably 450 to 1100 nm, and is decomposed by plasma to reduce the adhesion between the laser absorbing layer and the gas barrier layer, or the laser absorbing layer is separated from the gas barrier layer. I do.

Further, as a method of manufacturing such an easily cut packaging material, a method of manufacturing an easily cut packaging material by irradiating a laser beam to a packaging material in which a gas barrier layer, a laser absorbing layer and a film layer are sequentially laminated. Thus, while maintaining the continuity of the laser absorbing layer without being cut by the laser irradiation, at least a part of the adhesiveness between the layer and the layer in contact with the laser absorbing layer is reduced or the layer in contact with the laser absorbing layer. Provided is a method characterized by adjusting irradiation energy of a laser beam so as to exfoliate.

[0011] In particular, in the method of manufacturing the easy-cut packaging material, the laser absorbing layer is plasma-decomposed by irradiating a laser beam having a wavelength of 300 to 1200 nm, and at least a part of the laser absorbing layer adheres to the gas barrier layer. The present invention provides a method for reducing the property or peeling off the gas barrier layer.

The easy-cut packaging material of the present invention comprises a gas barrier layer, a laser absorbing layer and a film layer sequentially laminated, and at least a part of the laser absorbing layer is irradiated with a laser to form the laser absorbing layer. Adhesion with a layer in contact (for example, a film layer or a gas barrier layer) is reduced or peeled off. Therefore, according to the easy-cut packaging material of the present invention, it is possible to easily cut the laser-absorbing layer along the adhesion-reduced area or the peeled area. Furthermore, even in the area where the adhesion of the laser absorbing layer is reduced or the area where the laser absorbing layer is peeled off, the number of layers laminated there is not different from that of the other areas, so that the reduction in strength of the entire packaging material is suppressed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an easily cut packaging material 10 according to the present invention.
1A is a cross-sectional view illustrating a basic layer configuration of the present invention. As shown, the easy-cut packaging material 10A has a gas barrier layer 13, a laser absorbing layer 12, and a film layer 11 sequentially laminated.

The laser absorbing layer 12 has a portion thereof (region 1).
4) is subjected to laser irradiation and is plasma-decomposed by the irradiation, but maintains continuity and is separated from the gas barrier layer 13 at the gas barrier layer side interface 15. The film layer 11 also forms a continuous layer in close contact with the laser absorbing layer 12 without being damaged by the laser irradiation.

Here, the gas barrier layer 13 can be formed from a known aluminum thin film or ceramic thin film generally used for providing a high barrier property against air or water vapor.

The film layer 11 is provided for providing a sealing property or improving strength. The film layer 11 is made of a known polymer film material that is generally used for imparting a sealing property and has no or low absorbability to the laser irradiation acting on the laser absorbing layer 12. It can be appropriately selected and formed. More specifically, for example, polyethylene terephthalate (PET), expanded polypropylene (OPP),
Nylon and the like can be given.

The thickness of the film layer 11 is 1 in terms of strength.
It is preferably from 0 to 15 μm. The method for forming the film layer 11 is not particularly limited, and for example, can be formed by lamination.

The laser-absorbing layer 12 is a layer that forms a characteristic peeling area in the easily cut packaging material 10A.
This laser absorption layer 12 has a wavelength of 300 to 12 for example.
It can be formed from a laser-absorbing material that absorbs a laser of 00 nm, more preferably 450-1100 nm, decomposes by plasma, and thereby peels off from the gas barrier layer 13. As such a laser absorbing material, for example,
Wavelength 300-1200 nm, especially 450-1100 nm
And a printing ink (for example, a red ink for printing) containing a coloring agent such as a dye or a pigment having a high absorbency to the laser.

The laser absorbing layer 12 is formed on the gas barrier layer 13 and, as shown in FIG.
As a method of peeling off from the gas barrier layer 13, first, the laser absorbing layer 12 is formed uniformly on the gas barrier layer 13 by a wet printing method or the like, and then the film layer 11 is formed thereon, and then the wavelength is 300 to 1200 nm. More preferably, a laser having a wavelength of 450 to 1100 nm is applied to a region to be separated on the gas barrier layer 13 side of the region 14 of the laser absorption layer 12. In this case, as the irradiation conditions, for example, it is preferable that the irradiation intensity is about 10 MW / cm ² and the pulse width is about 10 nm. As a result, the laser absorbing layer 12 in the region 14 that has been irradiated with the laser is locally decomposed by plasma and evaporated. Then, with the stop of the laser irradiation, the gas barrier layer is again deposited on the spot, and the gas barrier layer side interface 15 is separated from the gas barrier layer 13.

In this laser irradiation, the irradiation energy is adjusted so that the laser absorbing layer 12 is separated from the gas barrier layer 13 at the gas barrier layer side interface 15 while maintaining continuity without breaking. By adjusting the irradiation energy, it is possible to prevent the formation of the kerf 4 like the conventional packaging material 10x shown in FIG. Therefore,
The easily cut packaging material 10A of the present invention has sufficient strength.

FIG. 2 is a cross-sectional view showing a layer structure of an easy-cut packaging material 10B according to another embodiment of the present invention. This easily cut packaging material 10B is also the above easily cut packaging material 10A.
Similarly to the above, the gas barrier layer 13, the laser absorption layer 12, and the film layer 11 have a layer configuration in which they are sequentially laminated,
In the laser absorbing layer 12, the interface 15 on the gas barrier layer side is not peeled off in the region 14 which has been subjected to the laser irradiation, and the adhesion to the gas barrier layer 13 is reduced. Therefore, the easy-cut packaging material 10B shown in FIG. 2 can be easily cut along the adhesion reduction region.

The method of manufacturing the easy-cut packaging material 10B of FIG. 2 is similar to that of manufacturing the easy-cut packaging material 10A of FIG. The irradiation energy of the laser may be appropriately adjusted so that peeling does not occur at the gas barrier layer-side interface 15 in the region 14 and the adhesion is reduced.

FIG. 3 is an explanatory view of a further different method of manufacturing the easy-cut packaging material 10C of the present invention. Figure 1 above
In addition, the easy-cut packaging materials 10A and 10B shown in FIG. 2 irradiate the area 14 of the laser absorbing layer 12 with a laser, thereby causing the gas barrier layer-side interface 15 of the area 14 to peel or reduce the adhesion. But
In the easily cut packaging material 10C shown in FIG. 3, first, FIG.
As shown in FIG. 7, an ink layer 12a having a high laser absorption as a laser absorption layer
6, a laser is applied to a linear region including the ink layer 12a having a high laser absorption and the ink layer 16 having a low laser absorption, and the laser is irradiated as shown in FIG. The separation is caused only at the gas barrier layer-side interface 15 of the highly absorbent ink layer 12a.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the present invention may have other layers than the above-described gas barrier layer 13, laser absorption layer 12, and film layer 11 as necessary. Can be.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments.

Example 1 An ink layer having a thickness of 3 μm was laminated as a laser absorbing layer on a 5 μm-thick aluminum layer (gas barrier layer) by a printing method, and a film layer 11 having a thickness of 1 μm was further formed thereon.
2 μm PET was laminated, and 12 μm thick OPP was laminated as an adhesive layer on the lower surface of the aluminum layer (gas barrier layer). After that, the obtained laminated sheet was cut into a size of 10 cm × 10 cm, and the two sheets were overlapped with the OPP surface inside, and as shown in FIG.
A side was heat-sealed to form a bag 20 (seal portion 21), and then a line L along the other side was irradiated with a yag laser to form an easy-cut portion. In this laser irradiation, the focus was set near the boundary between the laser absorbing layer and the gas barrier layer, and the irradiation conditions were as follows.

Laser irradiation conditions: wavelength: 532 nm, output: 10 MW / cm ² , pulse width: 20 ns

As a result of microscopic observation of the thus obtained packaging material, it was confirmed that a line-shaped peeling region having a width of 30 μm was formed in a portion where the laser absorbing layer was in contact with the gas barrier layer.

Comparative Example 1 A carbon dioxide laser (wavelength: 10 μm) was used in place of the irradiation of the yag laser of Example 1, and an easy-cut portion having a width of 30 μm was formed on the bag according to a conventional general-purpose easy-cut laser processing. . In the obtained easy-cut part, the PE on the bag surface
T melted and the surface of the aluminum layer was exposed.

Evaluation In order to evaluate the strength of each of the bags obtained in Example 1 and Comparative Example 1, 30 bags of each of both bags were filled with water and heat-sealed, and each of the samples was 5 m high. Then, the samples were naturally dropped on a concrete floor, and the degree of damage of the samples was compared.

As a result, 28 out of 30 samples of Comparative Example 1 were damaged, whereas only 3 out of 30 samples of Example 1 were damaged. The superiority of was confirmed.

[0033]

According to the present invention, it is possible to provide a packaging material having a gas barrier property with easy cutting at the time of opening while maintaining the strength required for the packaging material.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an easily-cut packaging material according to the present invention.

FIG. 2 is a sectional view of another embodiment of the easily cut packaging material of the present invention.

FIG. 3 is an explanatory view of a production method of another embodiment of the easily cut packaging material of the present invention.

FIG. 4 is a plan view of a bag manufactured in the example.

FIG. 5 is a cross-sectional view of a conventional easy-open packaging material.

FIG. 6 is a cross-sectional view of another embodiment of the conventional easy-open packaging material.

[Explanation of symbols]

 Reference Signs List 10A, 10B, 10C Easy-cut packaging material 11 Film layer 12 Laser absorption layer 12a Ink layer having high laser absorption 13 Gas barrier layer 14 Area of laser absorption layer irradiated with laser 15 Interface of laser absorption layer on gas barrier layer side 16 Laser Low absorbency ink layer 20 bags 21 seals

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Hideharu Maro 1-5-1, Taito, Taito-ku, Tokyo Letterpress Printing Co., Ltd.

Claims (6)

[Claims] A gas barrier layer, a laser absorbing layer, and a film layer are sequentially laminated, and at least a part of the laser absorbing layer is maintained while the laser absorbing layer maintains continuity without being cut by laser irradiation. An easy-cut packaging material characterized in that the adhesiveness to a layer in contact with the laser absorbing layer is reduced or the layer in contact with the laser absorbing layer is peeled off. 2. The laser absorbing layer absorbs, at least in part, a laser beam having a wavelength of 300 to 1200 nm and decomposes into plasma to reduce the adhesion to the gas barrier layer or to separate from the gas barrier layer. The easily cut packaging material according to claim 1. 3. A laser absorbing layer comprising a red ink,
2. The gas barrier layer comprises an aluminum thin film or a ceramic thin film, and the film layer comprises a polymer film.
Or an easily cut packaging material according to 2. 4. A method for producing an easily cutable packaging material by irradiating a laser beam to a packaging material in which a gas barrier layer, a laser absorption layer and a film layer are sequentially laminated, wherein the laser absorption layer is cut by laser irradiation. Adjusting the irradiation energy of the laser beam so that the adhesion to the layer in contact with the laser-absorbing layer is reduced or the layer is separated from the layer in contact with the laser-absorbing layer in at least a part thereof while maintaining the continuity without causing continuity. A method for producing an easy-cut packaging material, comprising: 5. The laser absorbing layer is plasma-decomposed by irradiating a laser beam having a wavelength of 300 to 1200 nm, and at least a part of the laser absorbing layer has reduced adhesion to a gas barrier layer or is separated from the gas barrier layer. A method for producing the easily cut packaging material according to claim 4. 6. The laser absorbing layer comprises a red ink,
5. The gas barrier layer comprises an aluminum thin film or a ceramic thin film, and the film layer comprises a polymer film.
Or the manufacturing method of the easily cut packaging material of 5.