JP7159686B2 - packaging bag - Google Patents

Description

TECHNICAL FIELD The present invention relates to a packaging bag provided with a window for viewing the inside.

A conventional packaging bag provided with a window is disclosed in Patent Document 1. This packaging bag accommodates food and the like, and is formed by heat-bonding the periphery of a resin film provided with an aluminum deposition film. The resin film is provided with a window portion (transparent portion) in which no aluminum deposition film is formed, and the contents filled in the packaging bag can be visually recognized through the window portion. In addition, since the aluminum deposition film has high gas barrier properties and light shielding properties, it is possible to prevent deterioration of the content due to moisture, oxygen, light, and the like.

JP 2012-126455 A (pages 3 to 5, FIG. 3)

The resin film forming the packaging bag is formed by laminating a vapor-deposited film provided with a vapor-deposited film and a film provided with a heat-adhesive resin via an adhesive or the like, and the window portion is filled with the adhesive or the like. Since the contents of the conventional packaging bag can be visually recognized through the window, customers often touch the contents by holding the window with their fingers. At this time, the contents may press the resin film on the window portion to form a pinhole in the window portion, and there is a problem that the gas barrier property of the packaging bag is deteriorated.

An object of the present invention is to provide a packaging bag that can prevent deterioration of gas barrier properties.

In order to achieve the above object, the present invention provides a laminated film obtained by laminating a vapor-deposited film in which a metal vapor-deposited film is arranged on a transparent base film, and a transparent interior film having at least a thermoadhesive resin layer. In the packaging bag adhered by the heat-adhesive resin layer, the laminated film has a window portion in which the metal deposition film is not formed, and a cavity is provided between the base film and the interior film in the window portion. It is characterized by

Further, according to the present invention, in the packaging bag having the structure described above, minute pieces of the vapor-deposited metal film are scattered in the window.

Further, according to the present invention, in the packaging bag configured as described above, the metal deposition film is made of aluminum.

According to the present invention, a cavity is provided between the base film in the window and the interior film having the thermoadhesive resin layer. When a customer or the like pinches the window and touches the contents, pinholes may be formed in the interior film due to the pressure of the contents. At this time, since the base film inside the window slides against the interior film due to the cavity, it becomes difficult for the pinholes to reach the base film. As a result, it is possible to prevent pinholes from penetrating the window portion and prevent deterioration of the gas barrier properties of the packaging bag.

BRIEF DESCRIPTION OF THE DRAWINGS The perspective view which shows the packaging bag of 1st Embodiment of this invention. FIG. 4 is a plan view showing another shape of the window portion of the packaging bag according to the first embodiment of the present invention; FIG. 2 is a cross-sectional view showing the laminated film of the packaging bag of the first embodiment of the present invention; Sectional drawing which shows the laminated film of the packaging bag of 2nd Embodiment of this invention Sectional drawing which shows the laminated film of the packaging bag of 3rd Embodiment of this invention

<First embodiment>
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a perspective view of the packaging bag of the first embodiment. The packaging bag 1 consists of a three-sided seal bag having an opening 1a at the upper end, and contains contents such as food (confectionery, rice, etc.), cosmetics, sanitary goods (shampoo, rinse, etc.).

The packaging bag 1 is formed by heat-bonding two sheets of laminated film 10 at three peripheral sides (both sides and a bottom side) with a sealing portion 3 . A sheet of laminated film 10 may be folded and two sides (both sides) of the peripheral portion may be heat-bonded by sealing portion 3 . After the content is filled in the packaging bag 1, the opening 1a is sealed by thermal bonding. One surface of the packaging bag 1 is formed with a circular window 5 through which the contents can be visually recognized.

The window portion 5 is not limited to a circular shape, and may be other figures (polygonal, elliptical, etc.) or patterns as shown in FIGS. 2(a) to 2(d). The hatched portions in FIGS. 2(a) to 2(d) are portions where the inside can be visually recognized.

FIG. 3 shows a cross-sectional view of the laminated film 10. As shown in FIG. Laminated film 10 is formed by laminating interior film 16 on the inner surface side of vapor-deposited film 11 . The deposition film 11 has a metal deposition film 13 deposited on the inner surface of a transparent base film 12 . As the base film 12, a biaxially oriented film such as a biaxially oriented polyethylene terephthalate film and a biaxially oriented nylon film can be used. An aluminum vapor deposition film can be used as the metal vapor deposition film 13 .

The window portion 5 of the laminate film 10 is formed by a region on the base film 12 where the metal vapor deposition film 13 is not formed, and can be formed by etching the metal vapor deposition film 13 . That is, after forming the metal deposition film 13 on the base film 12, the regions other than the region where the window portion 5 is to be formed are covered with a resist. Next, the window portion 5 is formed by removing the metal deposition film 13 in the region where the window portion 5 is to be formed with a sodium hydroxide solution or the like.

The method of forming the window 5 is not limited to the above, and the window 5 may be formed on the base film 12 by another method without the metal deposition film 13 formed thereon.

The interior film 16 has an adhesive layer 17 and a thermoadhesive resin layer 18 . The thermoadhesive resin layer 18 has thermoadhesiveness, and the thermoadhesive resin layers 18 of the two laminate films 10 are thermally adhered to form the seal portion 3 (see FIG. 1). A linear low-density polyethylene film, a polypropylene film, or the like can be used as the heat-adhesive resin layer 18 .

The adhesive layer 17 is made of extruded thermoplastic resin placed on the thermoadhesive resin layer 18 . A polyethylene resin or the like can be used as the extrusion resin.

The laminate film 10 is formed by stacking the interior film 16 on the inner surface of the vapor deposition film 11 with the adhesive layer 17 facing thereon and press-bonding. At this time, the extruded resin forming the adhesive layer 17 is heated to a temperature lower than the melting temperature, and the softened adhesive layer 17 and the metal deposition film 13 are adhered. Thereby, a cavity 14 into which the adhesive layer 17 does not enter is formed between the base film 12 and the adhesive layer 17 in the window portion 5 .

In the packaging bag 1 configured as described above, the contents are filled from the opening 1 a , and the opening 1 a is sealed with the thermoadhesive resin layer 18 . The contents can be visually recognized through the window portion 5 . In addition, since the vapor-deposited metal film 13 has high gas-barrier properties and light-shielding properties, it is possible to prevent deterioration of the contents due to moisture, oxygen, light, and the like. At this time, since the area of the window portion 5 is small, deterioration of gas barrier properties and light shielding properties is suppressed.

Further, when a customer or the like pinches the window portion 5 with fingers and touches the solid content, the pressure of the content may form a pinhole in the interior film 16 . At this time, since the base film 12 inside the window 5 slides on the interior film 16 due to the cavity 14 , it becomes difficult for the pinhole to reach the base film 12 . As a result, it is possible to prevent pinholes from penetrating the window portion 5 and prevent deterioration of the gas barrier properties of the packaging bag 1 .

Similarly, when a projection is pressed from the outer surface of the window portion 5, the base film 12 slides on the interior film 16, so that pinholes penetrating the window portion 5 can be prevented. As a result, deterioration of the gas barrier properties of the packaging bag 1 can be prevented even when the contents are liquid such as cosmetics and sanitary products.

According to this embodiment, the cavity 14 is provided between the base film 12 in the window portion 5 and the interior film 16 having the thermoadhesive resin layer 18 . Therefore, it is possible to prevent pinholes from penetrating the window portion 5 and prevent deterioration of the gas barrier properties of the packaging bag 1 .

Moreover, since the metal vapor deposition film 13 is made of an aluminum vapor deposition film, it is possible to easily realize a laminated film having high gas barrier properties and light shielding properties.

<Second embodiment>
Next, FIG. 4 is a sectional view showing the laminated film 10 of the packaging bag 1 of the second embodiment. For convenience of explanation, the same reference numerals are given to the same parts as in the first embodiment shown in FIGS. In the present embodiment, minute pieces 13a of the metal deposition film 13 are arranged in the window portion 5 in contrast to the first embodiment. Other parts are the same as in the first embodiment.

In the window portion 5, a plurality of columnar minute pieces 13a of the metal deposition film 13 bridging between the base film 12 and the adhesive layer 17 are scattered. A cavity 14 is formed between each minute piece 13a. The outline width of the minute piece 13a is formed to be several μm, for example.

The minute pieces 13a can be formed by forming the vapor-deposited metal film 13 on the base film 12, applying a resist to the regions where the minute pieces 13a are to be formed, and removing the vapor-deposited metal film 13. FIG.

According to this embodiment, in addition to the same effects as in the first embodiment, the windows 5 can be formed in a smoky shape because the plurality of minute pieces 13a are scattered. Therefore, the window portion 5 can be formed with a desired concentration according to the density of the minute pieces 13a, and the packaging bag 1 having the window portion 5 with different concentrations depending on the application can be easily realized. Therefore, the convenience of the packaging bag 1 can be improved.

The tips of the minute pieces 13 a arranged on the base film 12 may be separated from the adhesive layer 17 . The minute pieces 13a can be formed by removing the metal deposition film 13 up to the top of the base film 12, removing the resist, applying the resist again to areas other than the region where the window 5 is to be formed, and etching for a predetermined time.

<Third Embodiment>
Next, FIG. 5 is a sectional view showing the laminated film 10 of the packaging bag 1 of the third embodiment. For convenience of explanation, the same reference numerals are given to the same parts as in the first embodiment shown in FIGS. This embodiment differs from the first embodiment in the material of the adhesive layer 17 . Other parts are the same as in the first embodiment.

The adhesive layer 17 of the interior film 16 is made of a thermosetting adhesive for dry lamination such as urethane or acrylic, and is applied onto the thermoadhesive resin layer 18 . At this time, the adhesive layer 17 is formed by patterning, avoiding the region where the window portion 5 is to be formed. Then, the laminate film 10 is formed by stacking the interior film 16 on the inner surface side of the vapor deposition film 11 with the adhesive layer 17 facing.

As a result, a cavity 14 reaching the thermoadhesive resin layer 18 is formed between the base film 12 and the interior film 16 in the window portion 5 . Therefore, effects similar to those of the first embodiment can be obtained.

In the present embodiment, minute pieces 13a of the metal vapor deposition film 13 may be interspersed within the window portion 5 as in the second embodiment.

INDUSTRIAL APPLICABILITY According to the present invention, it can be used as a packaging bag for foods, cosmetics, sanitary products, and the like.

REFERENCE SIGNS LIST 1 packaging bag 3 seal portion 5 window portion 10 laminate film 11 vapor deposition film 12 base film 13 metal vapor deposition film 13a micro piece 14 cavity 16 interior film 17 adhesive layer 18 thermoadhesive resin layer

Claims (3)

A vapor-deposited film in which a metal vapor-deposited film is arranged on a transparent base film and a transparent interior film having a heat -adhesive resin layer are laminated via an adhesive to form a laminated film. In the bonded packaging bag, the laminated film has a window where the metal deposition film and the adhesive are not formed, and a cavity is provided between the base film and the interior film in the window. and packaging bag. 2. The packaging bag according to claim 1, wherein minute pieces of said vapor-deposited metal film are scattered in said window. 3. The packaging bag according to claim 1, wherein said metal deposition film is made of aluminum.

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