JP2015003762A - Packaging bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a packaging bag which preferably prevents breaking of the bag on falling while having a configuration suitable for sterilization using hydrogen peroxide.SOLUTION: A packaging bag is composed of a laminate film 10, and the laminate film includes a pinhole-resistant layer 20 containing a biaxial-orientation nylon film, a gas barrier layer 40 which contains a biaxial-orientation nylon film and is provided on one side of the pinhole-resistant layer, an inner layer part 30 provided on the other side of the pinhole-resistant layer and a protective outer layer 60 which is formed on the gas barrier layer and has a heat fusion layer 62. The inner layer part includes a first layer 31 composed of a linear very-low-density polyethylene of density of lower than 915 kg/m, measured by JIS K7112, a second layer 32 and a third layer 33 which are composed of a linear low-density polyethylene of density of 915 kg/mor higher, measured by JIS K7112 and formed each on both sides of the first layer in the thickness direction, with end parts of the layers joined, at least partially and integrally, by heat fusion.

Description

  The present invention relates to a packaging bag, and more particularly to a packaging bag suitable for aseptically filling a large volume and high fluid content.

  In a general aseptic filling and packaging system, a sterilization process using hydrogen peroxide may be performed. In this sterilization step, the packaging material is immersed in hydrogen peroxide solution and then dried.

  As a film suitable for a packaging material for aseptic filling packaging using hydrogen peroxide, a film described in Patent Document 1 is known. This film is a laminated film in which a heat-fusible layer is provided inside the stretched substrate film layer, and a protective film made of an unstretched resin film is laminated outside the stretched substrate film layer.

JP 2003-192017 A

  However, a packaging bag formed of a film having a three-layer structure such as a laminated film described in Patent Document 1 has a problem that bag breakage at the time of dropping cannot be sufficiently prevented.

  In view of the above circumstances, an object of the present invention is to provide a packaging bag that is suitably configured for sterilization using hydrogen peroxide and that can be suitably prevented from breaking when dropped.

The present invention is a packaging bag formed of a laminated film, the laminated film is formed including a pinhole-resistant layer formed including a biaxially stretched nylon film and a biaxially stretched nylon film, A gas barrier layer provided on one surface of the pinhole-resistant layer, an inner layer portion provided on the other surface of the pinhole-resistant layer, and a surface formed on the gas barrier layer and opposite to the gas barrier layer side and a protective layer having a heat sealable layer provided on said inner portion includes a first layer density measured by JIS K7112 is made of linear very low density polyethylene of less than 915kg / ^{m 3,} JIS K7112 The second layer and the third layer, each of which is formed of linear low density polyethylene having a density measured in step 915 kg / m ³ or more and formed on both sides in the thickness direction of the first layer, In the packaging bag, at least a part of the end portions where the inner layer portions are heat-sealed are joined together by heat-sealing using the heat-sealing layer.

The protective outer layer may include a first layer made of a biaxially stretched polypropylene film.
Alternatively, the protective outer layer is made of an unstretched film having a central portion made of an unstretched nylon film and a polyolefin layer formed on both surfaces in the thickness direction of the central portion, and the inner layer portion is a solvent-free type You may form by laminating | stacking on the said pinhole-resistant layer using an adhesive agent.

  The gas barrier layer may include any of a metaxylenediamine resin layer, an ethylene vinyl alcohol copolymer resin layer, a vinylidene chloride resin layer, and an inorganic compound layer.

  According to the packaging bag of this invention, it can be set as the packaging bag by which the broken bag at the time of a fall is prevented suitably, although it is a structure suitable for the disinfection using hydrogen peroxide.

It is a perspective view which shows the packaging bag of 2nd embodiment of this invention. It is sectional drawing of the laminated | multilayer film which comprises the packaging bag. It is sectional drawing of the laminated film which comprises the packaging bag of 2nd embodiment of this invention.

An embodiment of the present invention will be described with reference to FIGS. 1 and 2.
FIG. 1 is a perspective view showing a packaging bag 1 of the present embodiment. The packaging bag 1 is formed into a bag shape using a laminated film 10. The packaging bag 1 according to the present embodiment has both ends in a direction in which the tubular lumen extends after the end 10a and the end 10b of the single laminated film 10 are heat-sealed into a substantially cylindrical shape. It is formed in a bag shape by joining 10c and 10d by thermal fusion.
In the packaging bag of this invention, there is no restriction | limiting in particular in the procedure and method of forming a laminated film in a bag shape. For example, a packaging bag may be formed by arranging two laminated films so as to face each other and joining the peripheral portions by heat fusion, or other methods may be used.

  FIG. 2 is a cross-sectional view of the laminated film 10. The laminated film 10 includes a pinhole resistant layer 20 made of a biaxially stretched nylon film, an inner layer portion 30 provided on one surface of the pinhole resistant layer 20, and a gas barrier layer provided on the other surface of the pinhole resistant layer. 40 and a protective outer layer 60 provided on the gas barrier layer 40.

As the biaxially stretched nylon film constituting the pinhole-resistant layer 20, 6-nylon, 6,6-nylon, MXD (metaxylenediamine) nylon or the like can be used. The thickness of the anti-pinhole layer 20 can be appropriately set within a range of 5 to 100 μm, and is preferably set within a range of 10 to 50 μm.
The pinhole layer 20 exhibits the pinhole resistance and impact resistance of the packaging bag 1.

The inner layer portion 30 has a three-layer structure in which each layer is formed of linear low-density polyethylene, and functions as a sealant layer that is thermally fused. The central first layer 31 is made of a linear ultra-low density polyethylene having a density of less than 915 kg / m ³ measured according to JIS K7112, and the second layer 32 and the second layer 32 formed on both sides of the first layer 31 in the thickness direction. The three layers 33 are made of linear low-density polyethylene having a density measured by JIS K7112 of 915 kg / m ³ or more. The thickness of the inner layer part 30 can be appropriately set within a range of 5 to 300 μm, and is preferably set within a range of 10 to 100 μm.
There is no restriction | limiting in particular in the formation method of each layer of the inner layer part 30, Well-known various methods, such as co-extrusion and sandwich lamination, may be selected suitably. In the present embodiment, the inner layer portion 30 is formed by laminating the film having the above-described three-layer structure on the pinhole-resistant layer by dry lamination using the adhesive 51, but this is not essential. For example, it may be formed by applying a resin constituting each layer of the inner layer portion 30 on the anti-pinhole layer 20.

The configuration of the gas barrier layer 40 is as follows. 1. A biaxially stretched nylon film provided with a vapor deposition layer of an inorganic compound such as aluminum oxide or silicon oxide. 2. Biaxially stretched nylon film coated with vinylidene chloride resin 3. a biaxially stretched coextruded nylon film comprising a polyamide resin layer and an ethylene vinyl alcohol copolymer resin layer; A biaxially stretched coextruded nylon film including a polyamide resin layer and an MXD resin layer can be considered. The thickness of the barrier layer can be appropriately set within a range of 5 to 100 μm, preferably 10 to 50 μm. As the biaxially stretched nylon film used for the gas barrier layer 40, the same film as the pinhole resistant layer 30 can be used.
The gas barrier layer 40 is laminated on the pinhole resistant layer 20 by dry lamination using an adhesive 52.

The protective outer layer 60 includes a first layer 61 made of a biaxially stretched polypropylene film and a heat fusion layer 62 formed on the first layer 61. The protective outer layer 60 is formed by laminating a resin film including the first layer 61 and the heat fusion layer 62 on the gas barrier layer 40 by dry lamination using the adhesive 53.
The thickness of the protective outer layer 60 can be appropriately set within a range of 5 to 100 μm, preferably 15 to 40 μm.

As the adhesives 51, 52, 53 used for forming the laminated film 10, a solvent type, a water-based type, a non-solvent type, a heat-melting type or the like mainly composed of polyurethane, polyester, polyamide, epoxy or the like. Various laminating adhesives can be used. However, as the adhesive 51 for laminating the inner layer portion 30, it is preferable to use a solventless type from the viewpoint of reducing the amount of residual solvent that can penetrate into the packaging bag 1. The adhesive layer can be formed by coating the above-described laminating adhesive by, for example, roll coating, gravure coating, knife coating, deb coating, spray coating, or other coating methods. The application amount of the adhesive is preferably about 0.1 to 5 g / m ² (dry state).

  The packaging bag 1 is formed in a substantially quadrangular prism shape in which a folded portion of a gusset packaging is developed. In the upper end portion 10 c of the packaging bag 1 in the folded portion, the portion located on the upper portion of the folded portion is integrally joined by heat sealing using the heat-sealing layer 62. The lower end portion 10d of the packaging bag 1 is also integrally bonded by heat sealing using the heat-sealing layer 62 so as to form a rectangular bottom surface, and is fixed along the outer surface of the packaging bag. Yes. Thereby, the packaging bag 1 is exhibiting what is called a gable top-like shape as a whole.

The packaging bag 1 formed using the laminated film 10 configured as described above has the following advantages.
The inner layer portion 30 of the packaging bag 1 desirably has a low density from the viewpoint of impact resistance and pinhole resistance. However, when the density is low, there is a problem in that it shrinks when exposed to high temperatures in the sterilization dipping process using hydrogen peroxide in the aseptic filling and packaging system and the subsequent drying process.
Since the inner layer portion 30 of the present invention has a configuration in which the relatively low density first layer 31 is sandwiched between the relatively high density second layer 32 and the third layer 33, the first layer 31 is pinhole resistant. The heat resistance which can endure the sterilization immersion process of hydrogen peroxide water and the drying process can be ensured by the second layer 32 and the third layer 33 while adding the property and impact resistance.

Moreover, since the pinhole-resistant layer 20 and the gas barrier layer 40 are formed using a biaxially stretched nylon film, there are two nylon films in the center of the laminated film 10 in the thickness direction, and the rigidity is increased. Yes.
Further, since a flexible heat-sealing layer 62 is provided on the uppermost layer of the protective outer layer 60 that is the outer surface of the packaging bag 1, it absorbs shocks when dropped and is integrally joined by the heat-sealing layer 62. The upper and lower end portions 10c and 10d of the packaging bag thus made are more rigid than the unbonded state and are less likely to be destroyed.
Combined with these effects, bag breaking when the packaging bag 1 is dropped is suitably prevented. As a result, it is possible to obtain a packaging bag that is difficult to break while having a configuration suitable for sterilization using hydrogen peroxide.

There are many square-pillar packaging containers that use paper-containing packaging materials, such as milk cartons, for example, but with aseptic filling, the paper can be completely sterilized with hydrogen peroxide. The problem is that the fungus often propagates. If a square pillar-shaped packaging bag is formed using the above-mentioned laminated film 10, the above-mentioned problems can be solved because paper is not used, and more suitable sterilization filling can be performed.
Furthermore, since the lower end portion of the packaging bag 1 is fixed by thermal fusion so as to be along the surface of the packaging bag, it is easy to stand the packaging bag and efficiently transport and store it. it can.

A second embodiment of the packaging bag of the present invention will be described with reference to FIG. The difference between the packaging bag of the present embodiment and the packaging bag of the first embodiment is the layer structure of the laminated film as the material. In the following description, components that are the same as those already described are denoted by the same reference numerals and redundant description is omitted.
FIG. 3 is a cross-sectional view of the laminated film 11 forming the packaging bag of the present embodiment. The laminated film 11 includes a protective outer layer 70 instead of the protective outer layer 60. The protective outer layer 70 is formed by laminating a three-layer unstretched coextruded film on the gas barrier layer 40 by dry lamination using an adhesive 53.
In the laminated film 11, a solventless adhesive is used as the adhesive 51 for laminating the inner layer part 30.

The protective outer layer 70 includes a center portion 71 made of an unstretched nylon film, and unstretched polyolefin layers 72 and 73 formed on both surfaces of the center portion 71 in the thickness direction, respectively. The thickness of the protective outer layer 70 can be appropriately set within a range of 5 to 100 μm, and is preferably set within a range of 20 to 60 μm.
The polyolefin layer 73 constituting the outer surface of the packaging bag is a heat-sealable layer.

When forming the laminated film 10, first, the pinhole resistant layer 20 and the gas barrier layer 40 are bonded together by dry lamination using an adhesive 52. Next, the adhesive 53 is applied to the surface of the bonded material on the gas barrier layer 40 side, and the protective outer layer 70 is bonded. Finally, the adhesive 51 is applied to the surface of the material to which the protective outer layer 70 is bonded, which is on the pinhole resistant layer 20 side, and the inner layer portion 30 is bonded.
Here, when it is desired to remove the solvent contained in the adhesive for the purpose of preventing the influence on the contents, heating may be performed before lamination. In this embodiment, both of the protective outer layer 70 and the inner layer portion 30 are used. It is flexible and shrinks when heated. For this reason, the material which bonded the pinhole-proof layer 30 and the gas barrier layer 40 after application | coating of the adhesive agent 53 is heated, the protective outer layer 70 is bonded together after removing a solvent, without heating the protective outer layer 70 Perform lamination. Further, since the material to which the protective outer layer 70 is bonded cannot be heated, the solventless adhesive 51 is applied and the inner layer portion 30 is laminated by lamination without heating. Thereby, neither the inner layer part 30 nor the protective outer layer 70 is heated, and the laminated film 10 in which the solvent is not contained in the adhesive close to the contents can be formed. As a result, a packaging bag in which the adverse effect of the solvent does not affect the contents can be formed.
In the first embodiment, since the protective outer layer 60 includes the first layer 61 made of a biaxially stretched polypropylene film, it can withstand heating after being laminated on the gas barrier layer 40 and the pinhole resistant layer 20. It has become. Therefore, since the solvent can be removed by heating after applying the adhesive 51 to the material to which the protective outer layer 60 is bonded, even if the adhesive 51 for bonding the inner layer portion 30 is a solvent type, It is possible to make a laminated film in which a solvent is not contained in an adhesive close to the contents.

  In the packaging bag of this embodiment, since the surface of the protective outer layer 70 is formed of polyolefin, the wettability of the surface is low. Thereby, at the time of sterilization using hydrogen peroxide solution, the hydrogen peroxide solution adhering to the surface is quickly removed and quickly dried. Further, the central portion 71 having no hydrogen peroxide resistance is suitably protected by the polyolefin layers 72 and 73.

  In addition, since the inner layer portion 30 is bonded to the pinhole-resistant layer 20 with a solventless laminating adhesive 51, it is necessary to consider the residual solvent even when drying at a low temperature in order to prevent shrinkage of the unstretched film. There is no. Therefore, it can be suitably used as an aseptic packaging bag in which the influence of the residual solvent on the contents is reduced.

Hereinafter, although the packaging bag of this invention is further demonstrated with reference to an Example and a comparative example, this invention is not limited to the specific content of each example at all.
Example 1
As a material of the protective outer layer 60, a biaxially stretched polypropylene film (Futamura Chemical Co., Ltd., trade name: FOH, thickness 20 μm) on which a heat-sealing layer (layer thickness 2 μm) made of polyolefin was formed was used. A solvent-based adhesive (Mitsui Chemicals, Inc., trade name: A525) was applied to this film using a dry lamination machine, and an alumina-deposited biaxially-stretched nylon film (letter printing (15 mm) thick to be the gas barrier layer 40). Co., Ltd., trade name: GL-AEYBC). Next, the above-mentioned solvent-based adhesive is used to bond to a 15 μm thick biaxially stretched nylon film (Kojin Co., Ltd., trade name: Bonil W) to be the pinhole-resistant layer 20, and finally the above-mentioned solvent A linear low-density polyethylene film (Tamapoly Co., Ltd., trade name: MZ180) having a thickness of 80 μm was laminated using an adhesive based on the inner layer 30. The structure of the inner layer part 30 is: first layer 31: polyethylene having a thickness of 30 μm (900 kg / m ³ ), second layer 32 and third layer 33: both having a thickness of 20 μm (915 kg / m ³ ).
Using the laminated film formed as described above, a substantially gable-top type packaging bag as shown in FIG. 1 having a length of 90 mm, a width of 90 mm, a height of 200 mm, and a full volume of 1620 ml is produced. It was. In the packaging bag, the upper end portion 10c was integrally bonded by heat sealing using a heat-sealing layer, and the lower end portion 10d was fixed along the outer surface of the packaging bag by heat sealing.

(Example 2)
As a material for the protective outer layer 70, a non-stretched coextruded film (Tamapoly Co., Ltd., trade name: ZPB102) having a thickness of 40 μm was used. The protective outer layer is composed of a central portion 71: nylon having a thickness of 8 μm, and polyolefin layers 72 and 73: both having a thickness of 16 μm. A solventless adhesive (Toyo Ink Co., Ltd., trade name: ADN401) was used for the lamination of the inner layer part. Otherwise, the packaging bag of Example 2 was produced in the same procedure as in Example 1.

(Comparative Example 1)
Except that instead of the inner layer part, a single layer film (Mitsui Chemicals Tosero Co., Ltd., trade name: TUX-FCS, total layer density 920 kg / m ³ ) made of linear low density polyethylene was used. A packaging bag of Comparative Example 1 was produced in the same procedure as in Example 1.

(Comparative Example 2)
Packaging of Comparative Example 2 in the same procedure as Example 1 except that a single layer film (total layer density 914 kg / m ³ ) made of linear low density polyethylene was used instead of the inner layer part. A bag was made.

(Comparative Example 3)
Following the example described in Patent Document 1, a solvent-based adhesive A525 was applied to a biaxially stretched nylon film having a thickness of 15 μm (Kojin Co., Ltd., trade name: Bonil W) using a dry lamination machine, It bonded together with the ethylene-type polymer resin film. Furthermore, using the same solvent-based adhesive, a linear low-density polyethylene film (Tamapoly Co., Ltd., trade name: MZ180) having the same thickness of 80 μm as in Example 1 is laminated, and the packaging bag of Comparative Example 3 is obtained. did.

(Comparative Example 4)
Except that instead of the inner layer part, a single layer film (Mitsui Chemicals Tosero Co., Ltd., trade name: TUX-FCS, total layer density 920 kg / m ³ ) made of linear low density polyethylene was used. A packaging bag of Comparative Example 4 was produced in the same procedure as in Example 2.

(Comparative Example 5)
Packaging of Comparative Example 5 in the same procedure as Example 2 except that a single layer film (total layer density 914 kg / m ³ ) made of linear low density polyethylene was used instead of the inner layer part. A bag was made.

(Comparative Example 6)
Comparative Example 6 was carried out in the same procedure as Example 1 except that a biaxially stretched polypropylene film (Futamura Chemical Co., Ltd., trade name: FOR, thickness 20 μm) without a heat-fusible layer was used as the protective outer layer. A packaging bag was prepared. Since there was no heat-sealing layer, the end portions located above and below the folded portion were not joined together and were not fixed along the outer surface of the packaging bag.

(Comparative Example 7)
A packaging bag of Comparative Example 7 was produced in the same procedure as in Example 2 except that the above solvent-based adhesive A525 was used for the lamination of the inner layer part.

The following tests were conducted on the packaging bags of each example and each comparative example.
(Drop test)
Ten samples each of which was aseptically filled with 1200 ml of water in a packaging bag as described later were prepared, dropped from a position of 0.5 m in height, and the number of broken packaging bags was evaluated.

(Pitch measurement test)
Marking was printed on the outer surface of the packaging bag at regular intervals, the marking interval was measured before and after aseptic filling, and the reduction value of the interval was defined as the shrinkage amount of the packaging bag.
Aseptic filling was performed by a procedure in which the packaging bag before filling was dripped in a hydrogen peroxide solution heated to about 60 ° C., dried with warm air at 60 ° C., and then filled with the contents.

(Residual solvent measurement test)
A 100 mm square region was cut out from the laminated film of each example and was folded into four, and was cut into four along the fold line. The cut laminated film was put into a 20 ml vial, heated at 80 ° C. for 20 minutes by gas chromatography (manufactured by Agilent: 7890A), and the amount of residual solvent contained in the laminated film was measured.

  The results of each test are shown in Table 1.

As shown in Table 1, in the examples, there was no bag breakage in the drop test, whereas in Comparative Examples 1, 4, and 6, four samples were broken and in Comparative Example 3, seven samples were broken. In Comparative Examples 1 and 4, the inner side of the packaging bag lacks flexibility, and in Comparative Example 3, the biaxially stretched nylon film is not laminated in two layers. It was. Comparative Example 6 and Example 1 differ only in that there is no heat sealing layer on the outer surface and whether or not the end of the packaging bag is fixed by heat sealing. It was thought that it contributed to bag suppression.
In the laminated film using the solventless adhesive, the residual solvent could be kept low. In Comparative Example 6, although the solvent-based adhesive was used for the adhesive layer for laminating the inner layer portion, the solvent-based adhesive could be sufficiently heated by laminating the inner layer portion last, The solvent was kept low. However, in Comparative Example 7, since neither the protective outer layer nor the inner layer portion was able to withstand high heat, the residual solvent increased.
In the pitch measurement test, large shrinkage was observed in Comparative Examples 2 and 5. This was thought to be due to the remarkable shrinkage due to the low density of the inner polyethylene layer.

The embodiments and examples of the present invention have been described above. However, the technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be made to each component without departing from the spirit of the present invention. It is possible to add, delete, or combine the configurations of the embodiments.
For example, when a solvent-type adhesive is used for both the adhesive layer for laminating the inner layer portion and the adhesive layer for laminating the protective outer layer, the inner layer portion is formed after laminating the pinhole-resistant layer and the gas barrier layer. An adhesive layer for laminating is formed, the solvent is removed by heating, and then the inner layer portion is laminated. Thereafter, an adhesive layer for laminating the outer layer portion may be formed, and the protective outer layer may be laminated after heating at a lower temperature than usual. In this way, the residual solvent increases for the adhesive on the protective outer layer side, but the residual solvent decreases for the adhesive on the inner layer side, which has a large effect on the contents. It is possible to configure.

  Moreover, the packaging bag of this invention is not restricted to a substantially prismatic thing, It may be shapes, such as a gusset packaging of the state which is not expand | deployed in a prismatic shape, and pillow packaging. Even in such a case, the end portion of the so-called back side seal or the like that is joined when the end portion located in the folding portion is integrally joined by heat fusion or when the laminated film is formed into a cylindrical shape when forming a pillow package. Can be fixed to be along the outer surface of the packaging bag by heat fusion, thereby making it possible to make the packaging bag difficult to break.

DESCRIPTION OF SYMBOLS 1 Packaging bag 10, 11 Laminated film 20 Pinhole layer 30 Inner layer part 31 First layer 32 Second layer 33 Third layer 40 Gas barrier layer 51 Adhesive (solventless type adhesive)
60, 70 Protective outer layer 61 No. 1 layer 62 Thermal fusion layer 71 Center part 72, 73 Polyolefin layer

Claims (4)

A packaging bag formed of laminated film,
The laminated film is
A pinhole-resistant layer formed including a biaxially stretched nylon film;
A gas barrier layer formed including a biaxially stretched nylon film and provided on one side of the pinhole-resistant layer;
An inner layer provided on the other surface of the anti-pinhole layer;
A protective outer layer formed on the gas barrier layer and having a heat-sealing layer provided on the opposite side of the gas barrier layer;
With
The inner layer portion is
A first layer made of linear ultra-low density polyethylene having a density measured by JIS K7112 of less than 915 kg / m ³ ;
A second layer and a third layer, each of which is made of linear low-density polyethylene having a density measured by JIS K7112 of 915 kg / m ³ or more and formed on both sides in the thickness direction of the first layer. ,
A packaging bag in which at least a part of end portions where the inner layer portions are heat-sealed are integrally joined by heat-sealing using the heat-sealing layer.   The packaging bag according to claim 1, wherein the protective outer layer includes a first layer made of a biaxially stretched polypropylene film. The protective outer layer is
A central portion made of an unstretched nylon film;
A polyolefin layer formed on both sides in the thickness direction of the central portion, and an unstretched film having
The packaging bag according to claim 1, wherein the inner layer portion is formed by laminating the pinhole-resistant layer using a solventless adhesive.   The packaging bag according to any one of claims 1 to 3, wherein the gas barrier layer includes any one of a metaxylenediamine resin layer, an ethylene vinyl alcohol copolymer resin layer, a vinylidene chloride resin layer, and an inorganic compound layer.

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