JP2001009965A - Packaging material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a gray color-darkening, and improve an whitening effect by providing at least two layers of white coloring layers, and inserting at least one layer of a synthetic resin film layer between the white coloring layers in a laminated body for packaging, which includes an aluminum layer. SOLUTION: This packaging material 1 for foods, beverages and medicines or the like for which a high gas barrier property and a light-shielding property are required, is formed by providing a white coloring layer 3a, a transparent synthetic resin film layer 4 and a white coloring layer 3b, on one surface of an aluminum layer 2. By this constitution, the improvement of the brightness by an angle of incidence, and the suppressing effect of a gray color which the aluminum layer 2 has can be increased. The synthetic resin film 4 is not specifically limited, and a drawn film of polyethylene, polyvinyl chloride, and a polyamide based resin or the like can be used. In this case, the thickness is preferably 3 μm or higher, more preferably, is set in a range of 3 to 200 μm. Also, for the aluminum layer 2, an aluminum foil or a deposited aluminum can be used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention suppresses the darkening of print appearance when an aluminum layer is used in packaging materials for foods, beverages, pharmaceuticals, etc., which require high gas barrier properties and light shielding properties. The present invention relates to a packaging material in which the appearance of various displays is improved and the appearance of color printing is improved by improving whiteness or brightness.

[0002]

2. Description of the Related Art Many types of packaging materials for foods, beverages, pharmaceuticals, etc. have been produced since ancient times, but the dark color has a poor image, and it is difficult to understand when foreign substances are attached. There is a tendency, and a whiter packaging material has been demanded in order to make various displays easy to see and color printing to look good. However, when an aluminum layer having excellent performance of blocking oxygen, moisture and the like is used, the gray color of aluminum lowers the whiteness of the print layer and causes a problem that the entire print layer becomes dark. In the prior art, in order to improve whiteness, a method of applying a white paint (including a white ink) twice to one synthetic resin film layer and superimposing two white coloring layers, or kneading a white pigment. However, the two-layer method has a limitation in improving the whiteness, and the kneaded film has a problem that the cost is high and the resin used is limited. is there.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a packaging material using an aluminum layer by laminating a plurality of white layers to suppress grayish darkening and enhance the whitening effect.

[0004]

To solve the above-mentioned problems, the present invention relates to a packaging laminate including an aluminum layer,
It has at least two white colored layers, and two of these white colored layers
At least one synthetic resin film layer is interposed between the layers.

The thickness of the synthetic resin film layer is 3 μm
The above is preferable, and the upper limit is 200 μm. When an aluminum foil is used as the aluminum layer, at least two white colored layers are provided on the matte side of the aluminum foil, and at least one or more synthetic resin film layers are interposed between the two white colored layers. It is better to let.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a packaging material 1 according to the present invention has a white coloring layer 3a, a transparent synthetic resin film layer 4, and a white coloring layer 3b provided on one surface of an aluminum layer 2. . The illustration of the adhesive layer is omitted in the figure.

As the aluminum layer 2, an aluminum foil having a thickness of 4 to 50 μm and a deposited aluminum having a thickness of 300 to 1200 angstroms can be used. The purity and components of aluminum are not particularly limited. For example, 1000 series, 3000 series, 5000 series, 8000 series specified in JIS
Pure aluminum or aluminum alloy such as aluminum alloy can be used.

The synthetic resin film 4 located between the white coloring layers 3a and 3b is not particularly limited, and a known synthetic resin film can be used. However, in view of cost and versatility, various types of polyethylene (PE), polypropylene Stretched films such as (PP), polyvinyl chloride (PVC), polyamide resin (nylon: NY), and polyethylene terephthalate (PET) can be used. Its thickness is preferably 3
It is not less than μm, more preferably 3 to 200 μm. Three
If it is less than 200 μm or less than 200 μm, it is not preferable in terms of industrial productivity and economy. That is, a film having a thickness of less than 3 μm has extremely low strength and is likely to be accompanied by a risk of breakage or perforation during coating (during printing). The other 200
If it exceeds μm, it will lead to cost increase,
It is not preferable because easy opening property and flexibility are impaired.

The paint (ink) used for the white colored layers 3a and 3b contains at least titanium oxide, and other vehicle components are not particularly limited. A known or commercially available paint (ink) may be used. Can be. Further, if necessary, it may contain a pearl pigment such as mica. The thickness after drying per white coloring layer is 0.5 to 15
μm is preferred, and if it is less than 0.5 μm, the whiteness may be insufficient. If it exceeds 15 μm, economical efficiency and workability are deteriorated, such as increased cost and longer drying time.

In a preferred embodiment of the present invention, as shown in FIG. 2, two synthetic resin films 4a and 4b each having a white coloring layer formed by applying a white paint on one surface are prepared.
This may be bonded using an adhesive, and the laminate and the aluminum foil 2a may be bonded using an adhesive. Alternatively, a white coloring layer 3 may be formed on both sides of the synthetic resin film 4a.
a, 3b, and aluminum foil 2a on one outer surface.
Alternatively, a resin film 4b separately prepared may be adhered to the other surface. In these cases, it is preferable to bond the aluminum foil 2a to the matte side of the aluminum foil 2a in order to improve whiteness. Of course, in the present invention, the white colored layer is not limited to two layers, but three or more layers may be provided, and a configuration in which a white colored layer / synthetic resin film layer / white colored layer is formed on both surfaces of the aluminum foil 2a. Can also be adopted.

The packaging material of the present invention may further include an overcoat layer, an adhesive layer, an anchor coat layer, a printing layer, a colored layer other than white, a heat-adhesive resin layer, an outer protective film, A reinforcing resin film or the like can be laminated. FIG.
An example is shown below. In the figure, reference numeral 5 denotes a printing layer, 6 denotes an outer surface protection film, and 7 denotes a thermal adhesive layer. The synthetic resin film and the outer protective film used in the present invention may be subjected to a matting treatment as required (matting treatment: treatment for reducing the gloss and transparency of the film surface by sandblasting or the like).
Can also be applied. In addition, the same known resin film as the synthetic resin film can be used for the outer surface protection film and the reinforcing resin film.

As described above, by interposing the synthetic resin film between the two white coloring layers, it is considered that whiteness is improved because incident light is refracted and reflected at least twice. The gray color of the aluminum layer is considered to be inconspicuous from the laminate surface (incident light side) because it is refracted and diffusely reflected by the white coloring layer and the synthetic resin film.

The size and shape of the packaging material 1 can be arbitrarily set according to the contents to be packaged.
It can be supplied or used as a P, a container, a simple sheet, and the present invention includes all of them. Although the contents of the packaging material of the present invention are not particularly limited, foods and beverages are particularly preferable.

[0014]

EXAMPLES AND COMPARATIVE EXAMPLES A packaging material having the structure shown in FIG. 4 (the number of the structure indicates a thickness of μm) was prepared by a conventional method. In the figure,
PET is polyethylene terephthalate film, OPP
Indicates a stretched polypropylene film, and Univia A Tokushiro (manufactured by Dainippon Ink and Chemicals, Inc.) was used for white coloring. AL indicates JIS 8021 aluminum foil (manufactured by Toyo Aluminum Co., Ltd.), and D indicates a dry laminating adhesive (manufactured by Toyo Morton Co., Ltd.).

Example 1 A white ink was dried on one side of a 12 μm PET film using a gravure roll to a thickness of 2 μm.
m were prepared, and one of the white colored surfaces and the other PET surface were bonded together using a dry laminating adhesive (about 4 g / m ² after drying). The laminate was further bonded to a 7 μm aluminum foil on the second white side using a dry laminating adhesive (about 4 g / m ^{2 in} weight after drying).

Example 2 A 12 μm PET film was prepared by applying white ink to both sides of a 12 μm PET film using gravure rolls to a thickness of 2 μm after drying, and a PET film prepared separately from one white coloring surface. Lamination was performed using a dry laminating adhesive (about 4 g / m ^{2 in} weight after drying). Further, 7 μm was applied to the white coloring 2 side of the laminate using a dry laminating adhesive (about 4 g / m ² after drying).
m and aluminum foil.

Example 3 A laminate was prepared in the same manner as in Example 1 except that the PET film was replaced with a stretched polypropylene film.

Example 4 A laminate was produced in the same manner as in Example 2 except that the PET film was replaced with a stretched polypropylene film.

Comparative Example 1 A white ink was dried on one side of a 12 μm PET film using a gravure roll and dried to a thickness of 2 μm.
m were prepared, and the two white colored surfaces were bonded to each other using a dry laminating adhesive (weight after drying: about 4 g / m ² ). One of the PET surfaces of the laminate was bonded to a 7 μm aluminum foil using a dry laminating adhesive (about 4 g / m ^{2 in} weight after drying).

[Comparative Example 2] A 50 μm stretched polypropylene film was prepared by applying a white ink to one side of a 50 μm stretched polypropylene film using a gravure roll and then applying a thickness of 4 μm. A separately prepared polypropylene film and three white coloring sides were dry-laminated. Lamination was carried out using an adhesive (weight about 4 g / m ² after drying). The laminate was further bonded to a 7 μm aluminum foil using a dry laminating adhesive (about 4 g / m ² after drying).

With respect to the laminates produced in the above Examples and Comparative Examples, the surface on the coloring side was observed from a position 1 m away under a fluorescent lamp. In FIG. 4, a circle in the column of evaluation indicates that the gray light due to aluminum was completely blocked and pure white, and a cross indicates that the gray light due to aluminum was transparent and grayish white.

[0022]

According to the present invention, as described above, since the synthetic resin film is interposed between the white colored layers and the aluminum layer is laminated, the number of refractions and reflections increases, and the whiteness of the incident light is reduced. Thus, the effect of suppressing the gray color of the aluminum layer can be enhanced.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an example of a packaging material of the present invention.

FIG. 2 is a schematic sectional view showing another example of the packaging material of the present invention.

FIG. 3 is a schematic sectional view showing still another example of the packaging material of the present invention.

FIG. 4 is a table showing a laminated structure and evaluation of an example and a comparative example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Packaging material 2, 2a Aluminum layer 3a, 3b White coloring layer 4, 4a, 4b Synthetic resin film 5 Printing layer 6 Outer surface protection film 7 Thermal adhesive layer

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B65D 81/30 B65D 81/30 A (72) Inventor Masafumi Yamamoto 3-6-8 Kutaro-cho, Chuo-ku, Osaka-shi No. Toyo Aluminum Co., Ltd. F-term (reference) 3E067 AA03 AB01 AB26 AB81 BB12A BB14A BB15A BB16A BB25A CA04 CA12 EE02 GD05 3E086 BA04 BA13 BA15 BB01 BB21 CA01 CA11 CA28 4F100 AB10A AB33A AK01C00B00CC00 BA00 CC00B00CC GB23 GB66 HB31B HB31D JD02 JL10B JL10D JN30

Claims (4)

[Claims] 1. A packaging laminate including an aluminum layer, wherein at least two white colored layers are provided, and at least one synthetic resin film layer is interposed between the two white colored layers. And packaging material. 2. The synthetic resin film layer has a thickness of 3 μm.
The packaging material according to claim 1, which is the above. 3. The synthetic resin film layer has a thickness of 3 to 2.
The packaging material according to claim 1, which has a thickness of 00 µm. 4. The aluminum layer is made of aluminum foil, at least two white colored layers are provided on the matte side of the aluminum foil, and at least one synthetic resin film is provided between the two white colored layers. The packaging material according to any one of claims 1 to 3, wherein a layer is interposed.