JP2015048094A - Light blocking packaging bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light blocking packaging bag made by considering demands such as withstanding filling, transportation and preservation on actual use while satisfying content protection performance by light blocking properties and barrier properties without poor appearance as a packaging bag, preventing poor appearance caused by a pin hole, and avoiding a decrease in content protection performance, and especially, eliminating poor appearance caused by fish eye so as to eliminate occurrence of a pin hole.SOLUTION: A packaging bag in which three sides of overlapped laminated films are sealed, and an opening is sealed and enclosed after filling content from the opening is configured such that the laminated films are obtained by arranging a biaxial drawing polypropylene film 1 as the outermost layer, a film made by sticking a barrier film 3 and a biaxial drawing white nylon film 5 as the intermediate layer, and a black polyethylene film 7 as the innermost layer, and the outermost layer and the intermediate layer are stuck to each other, and the intermediate layer and the innermost layer are stuck to each other, by an extrusion lamination system using polyolefin resin.

Description

  The present invention relates to a packaging bag that can be used for packaging contents whose quality easily changes due to the invasion of oxygen, moisture and light in the fields of pharmaceuticals and foods.

If the contents may be discolored, deteriorated, or altered by light, the filled packaging bag may be further covered with a light-shielding material or a light-shielding packaging bag may be used in advance. It is common.
As a packaging bag having a light shielding property, a poly bag type in which a certain amount of a light shielding agent is contained in thick polyethylene and an aluminum bag type in which a film and an aluminum foil are laminated are known.

  Among these, aluminum bags have excellent gas barrier properties and excellent barrier effects such as moisture resistance and oxidation prevention, but it is inevitable that the bags will become harder than the poly bag type, and depending on the application, there are difficulties in handling and price. It is expensive.

  On the other hand, in the plastic bag type, the required quality differs depending on the contents to be protected, and therefore, a laminate of various films and resins in addition to polyethylene is widely used in accordance with the performance according to the application.

Japanese Patent No. 4170414

  The patent document uses a coextruded polyethylene film obtained by coextruding a polyethylene resin mixed with a white pigment in the innermost layer of a packaging bag and a polyethylene resin mixed with a gray pigment and a brown pigment. When this occurs, the fish eye is transparent, so that the gray or brown of the intermediate layer can be seen through, and the quality of the appearance cannot be maintained. Fish eyes generally occur intermittently in the process of forming a polyethylene film, and especially with colored polyethylene resins in which a large amount of pigment is kneaded into polyethylene, fish eyes are more likely to occur, resulting in poor appearance due to fish eyes. It has been difficult to achieve zero.

  In general, a polyethylene film tends to cause fish eyes as compared with a nylon film. In addition, polyethylene film is often used as a sealant in the packaging material, and in that case, since the ratio of the polyethylene film is large in the packaging material, the frequency of occurrence tends to increase when viewed as a whole packaging material. Further, when a film is formed by mixing different pigments in each layer with a coextruded film as in Patent Document 1, there is a possibility that a difference occurs in the extrusion conditions of each layer, so that fish eyes are more likely to occur. Tend. Therefore, in order to color a film, coloring with a single film can suppress the generation of fish eyes.

As a packaging bag, it must be able to withstand filling, transportation and storage in actual use while satisfying the content protection performance due to light shielding and gas barrier properties as well as eliminating appearance defects. In addition, when the contents are liquid, pinholes may be generated during transportation and storage, so that it is necessary to prevent the appearance defect and decrease the protection performance of the contents.
The present invention has been made in view of the above-described requirements, and in particular, an object of the present invention is to provide a light-shielding packaging bag that can eliminate appearance defects due to fish eyes and can eliminate the occurrence of pinholes.

  As a means for solving the above-mentioned problems, the invention according to claim 1 is a packaging bag in which three sides of the stacked laminated film are sealed, and after the contents are filled from the opening, the opening is sealed and sealed. The laminated film has a biaxially stretched polypropylene film as the outermost layer, a film in which a barrier film and a biaxially stretched white nylon film are bonded to the intermediate layer, and a black polyethylene film as the innermost layer, and the outermost layer, the intermediate layer and the intermediate layer. The innermost layer is a light-shielding packaging bag that is bonded by an extrusion laminating method using a polyolefin resin.

  The invention according to claim 2 is characterized in that the biaxially stretched white nylon film and the barrier film are bonded together by a dry laminating method using a urethane-based adhesive. It is a packaging bag.

The light-shielding packaging bag according to the present invention can conceal fish eyes that can occur in the innermost black polyethylene film by disposing a biaxially stretched white nylon film as an intermediate layer, resulting in poor appearance and reduced light-shielding performance. Can be prevented.
Further, by adopting an extrusion lamination method for bonding the outermost layer and the intermediate layer and between the intermediate layer and the innermost layer, it is possible to prevent the occurrence of pinholes due to a vibration test assuming transportation and storage after filling.

  In addition, by bonding the biaxially stretched white nylon film and the barrier film by a dry laminate method using a urethane adhesive, it becomes possible to give the adhesive strength between the films and to prevent the occurrence of pinholes. .

These are the cross-sectional schematic diagrams of one embodiment which concerns on this invention, and respond | correspond to Example 1. FIG. These are the cross-sectional schematic diagrams of one embodiment which concerns on this invention, and respond | correspond to the comparative example 1. FIG. These are the cross-sectional schematic diagrams of one embodiment which concerns on this invention, and respond | correspond to the comparative example 2. FIG. These are the cross-sectional schematic diagrams of one embodiment which concerns on this invention, and respond | correspond to the comparative example 3. FIG.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.
In each figure, the upper side of the figure is the outer surface as a packaging bag, and the lower side is the inner surface in contact with the contents.

As shown in FIG. 1, the embodiment of the present invention is a composite of a film and a resin, and includes an outermost layer, an intermediate layer, and an innermost layer.
That is, this invention has a biaxially stretched polypropylene film (1) used as a printing base material as an outermost layer.
The intermediate layer is formed by laminating a barrier film (3) and a biaxially stretched white nylon film (5) via a urethane adhesive (4).
The intermediate layer provides pinhole resistance and puncture resistance of the packaging bag, oxygen barrier properties and water vapor barrier properties, and concealment properties by the biaxially stretched white nylon film (5). As an innermost layer, it has a black polyethylene film layer (7) for providing light-shielding properties. Furthermore, in order to prevent the occurrence of pinholes during transportation and storage, an extruded polyolefin resin layer (2) is provided as an adhesive layer between the outermost layer and the intermediate layer using an extrusion lamination method, and between the intermediate layer and the innermost layer. Similarly, an extruded polyolefin resin layer (6) is provided as an adhesive layer.

  As the outermost layer constituting the packaging bag, a biaxially stretched polypropylene film having wear resistance is used. As thickness of a base material layer, it can set suitably in the range of 5-100 micrometers, Preferably it is 20-40 micrometers.

  Among the intermediate layers that make up the packaging bags, barrier films include films of saponified ethylene / vinyl acetate copolymer, polyvinylidene chloride, polyacrylonitrile, and transparent deposited layers of inorganic oxides such as silica and alumina. A biaxially stretched nylon film, a biaxially stretched polyethylene terephthalate film, a biaxially stretched polypropylene film or the like provided with a coating layer of vinylidene chloride can be used. As thickness of a barrier film, it can set suitably in the range of 5-100 micrometers, Preferably it is 10-30 micrometers.

  As the biaxially stretched white nylon film in the intermediate layer constituting the packaging bag, first of all, the innermost black polyethylene film plays a role of preventing and concealing the surface layer. In addition, a film in which pinhole resistance and impact resistance are imparted and white pigment is blended with 6-nylon, 6,6-nylon, MXD nylon, or the like can be used. The thickness can be appropriately set within a range of 5 to 100 μm, preferably 10 to 30 μm.

  As the innermost layer constituting the packaging bag, a black linear low-density polyethylene film containing a pigment such as carbon is used, and the thickness of the innermost layer is set within a range of 5 to 300 μm, preferably 10 to 100 μm. Can do.

The extruded polyolefin resin layer adheres the outermost layer and the intermediate layer, and the intermediate layer and the innermost layer. For example, low-density polyethylene is melt-extrusion coated on one of these films and laminated on the other film before solidifying. And let it adhere.
Such an extruded polyolefin resin layer can be appropriately selected from commercially available low density polyethylene resins. The thickness of the extruded resin layer is desirably about 5 to 30 μm.
Prior to melt extrusion coating the extruded polyolefin resin layer, an anchor coat layer (AC) may be provided on the extruded surface of the film.

  The adhesive layer constituting the packaging bag is for adhering the biaxially stretched white nylon film and the barrier film, and is not particularly limited as long as it is a commercially available two-component curable urethane adhesive, and the thickness is about 3 μm. Is desirable.

Hereinafter, the light-shielding packaging bag of the present invention will be described based on specific examples.
<Production of laminated film>
Barrier film (3) Thickness 15 μm (Toppan Printing Co., Ltd., trade name: GL-AEY) and biaxially stretched white nylon film (5) Thickness 15 μm (Unitika) were used with urethane adhesive (Mitsui) Chemical Co., Ltd., trade name: A525) was applied with a dry film thickness of 3 μm and bonded.
Next, an anchor coating agent (Toyo Ink Co., Ltd., trade name: EL451) was applied to the biaxially stretched polypropylene film (1) (Futamura Chemical Co., Ltd., trade name: FOR) using an extrusion lamination machine, The barrier film surface of the previous laminated film was bonded to the extruded polyolefin resin layer (2) with a thickness of 15 μm.
An anchor coat agent (Toyo Ink Co., Ltd., trade name: EL451) is applied to the biaxially stretched nylon film surface of the laminated film in this way using an extrusion lamination machine, and a linear low density black polyethylene film. (7) Thickness 40 μm (Tamapoly Co., Ltd., trade name: UB1 black) was bonded at an extruded polyolefin resin layer (6) thickness of 15 μm to produce a laminated film according to the present invention.
(Making a packaging bag)
Further, the innermost surfaces of the laminated film were overlapped and sealed on three sides to prepare a light-shielding packaging bag, filled with the contents, and then the opening was sealed to prepare a light-shielding packaging bag.
(Evaluation)
In the light shielding packaging bag, the number of pinholes generated by a vibration test and the number of fish eyes by an appearance inspection were evaluated.

<Comparative Example 1>
(Creation of laminated film)
An anchor coating agent (Toyo Ink Co., Ltd., trade name: EL451) was applied to the printing surface of the biaxially stretched polypropylene film (1) (Futamura Chemical Co., Ltd., trade name: FOR) using an extrusion lamination machine. The film was laminated with a barrier film thickness of 15 μm (Letterpress Printing Co., Ltd., trade name: GL-AEY) and an extruded polyolefin resin layer of 15 μm.
An anchor coating agent (Toyo Ink Co., Ltd., trade name: EL451) was applied to the barrier film surface of the laminated film using an extrusion lamination machine, and a linear low density colored polyethylene film (11) having a thickness of 40 μm (thickness). 10 μm linear low density polyethylene layer (8) / 20 μm thick brown linear low density polyethylene layer (9) / 10 μm thick white linear low density polyethylene layer (10): Patent 4170414 (Example 1) ) Was laminated so that the linear low density polyethylene layer (8) was the innermost layer, and Comparative Example 1 was produced.
The layer structure is as shown in the schematic diagram of FIG.
(Making a packaging bag)
The packaging bag creation method is the same as that in the first embodiment.
(Evaluation)
In the packaging bag, the number of pinholes generated by a vibration test and the number of fish eyes by an appearance inspection were evaluated.

<Comparative example 2>
(Creation of laminated film)
In Comparative Example 1, a linear low density colored polyethylene film (13) having a thickness of 40 μm and a linear low density polyethylene layer (8) having a thickness of 10 μm / gray linear low density polyethylene layer (12) having a thickness of 20 μm / thickness Comparative Example 2 was prepared in the same manner as Comparative Example 1 except that a white linear low-density polyethylene layer having a thickness of 10 μm (10): Patent 4170414 (Example 2) was used.
The layer structure is as shown in FIG.
(Making a packaging bag)
The packaging bag creation method is the same as that in the first embodiment.
(Evaluation)
In the packaging bag, the number of pinholes generated by a vibration test and the number of fish eyes by an appearance inspection were evaluated.

<Comparative Example 3>
(Creation of laminated film)
In Example 1, urethane adhesive (4) using a dry lamination machine for all the layers of the biaxially stretched polypropylene film, the barrier film, the biaxially stretched white nylon film, and the linear low density black polyethylene film. (Mitsui Chemicals Co., Ltd., trade name: A525) was coated with a dry film thickness of 3 μm, and the laminated product was bonded to Comparative Example 3.
The layer structure is as shown in FIG.
(Making a packaging bag)
The packaging bag creation method is the same as that in the first embodiment.
(Evaluation)
In the packaging bag, the number of pinholes generated by a vibration test and the number of fish eyes by an appearance inspection were evaluated.

Evaluation method:
Vibration test: A bi-directional switching type vibration test apparatus manufactured by SHINKEN Co., Ltd. was used.
Vibration condition: ± 4G (11Hz), total 60 minutes (vertical direction 30 minutes + vertical 15 minutes + horizontal 15 minutes)
Evaluation method: A 310 mm × 265 mm outer bag was made, an inner bag filled with 1 liter of inner solution was packed, loaded and packed, subjected to a vibration test under the above conditions, and the number of pinholes was counted with an osmotic solution. (10 bags / 1 cardboard).
The results are shown in Table 1.
Visual inspection:
Evaluation method: 1000 exterior bags of 310 mm × 265 mm were prepared, and the number of bags in which generation of fish eyes could be confirmed from the outermost layer or black polyethylene could be seen through was counted.
The results are shown in Table 1.

The light-shielding packaging bag according to the present invention has a pinhole resistance equal to or higher than that of Comparative Examples 1 to 3, results in no appearance failure, and verifies that the problem can be solved. I was able to.

DESCRIPTION OF SYMBOLS 1 ... Biaxially stretched polypropylene film 2 ... Extruded polyolefin resin layer 3 ... Barrier film 4 ... Urethane adhesive 5 ... Biaxially stretched white nylon film 6 ... Extruded polyolefin resin layer 7 ... Linear low density black polyethylene film 8 ... Linear low density polyethylene layer 9 ... Brown linear low density polyethylene layer 10 ... White linear low density polyethylene layer 11 ... straight Linear low density colored polyethylene film 12 ... Gray linear low density polyethylene layer 13 ... Linear low density colored polyethylene film

Claims (2)

In the light-shielding packaging bag that seals and seals the opening after the three sides of the laminated film are sealed and filled with the contents from the opening,
The laminated film has a biaxially stretched polypropylene film as the outermost layer, a film in which a barrier film and a biaxially stretched white nylon film are bonded to the intermediate layer, and a black polyethylene film as the innermost layer, and the outermost layer, the intermediate layer, and the intermediate layer The innermost layer is a light-shielding packaging bag that is bonded by an extrusion laminating method using a polyolefin resin. The light-shielding packaging bag according to claim 1, wherein the biaxially stretched white nylon film and the barrier film are bonded together by a dry laminating method using a urethane-based adhesive.