JP2006282237A - Packaging materials and flexible containers - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a packaging material with good tearability and no flexible smell inside, and a flexible container using the same.
SOLUTION: A tearable packaging material (flexible material 1) having a heat fusion layer 2 having a heat fusion property, a gas barrier layer 3 having a gas barrier property, and a mechanical strength. A laminate including the protective layer 4 is included, and the heat-fusible layer 2 is exposed on the surface of the laminate. As the gas barrier layer 3, an alumina oxide coated polyethylene terephthalate (CPET) film is used. In addition, a polyethylene (PE) film or the like can be used as the heat sealing layer 2, and a nylon (NY) film or the like can be used as the protective layer 4.
[Selection] Figure 1

Description

  The present invention relates to a packaging material using a flexible material that can be teared and opened and used for commercialization, transportation or storage of liquids such as drinking water and pure water, and a flexible container using the packaging material.

  Generally, synthetic resin containers called PET bottles are frequently used for the commercialization, transport and storage of drinking water such as mineral water and other liquids. Examples of the synthetic resin container include an emergency drinking water container described in JP-A-8-198231 (see Patent Document 1). Although this type of synthetic resin container is lightweight and highly safe, it is pointed out that it is bulky and difficult to handle because it has high rigidity and has a fixed shape regardless of the content. In contrast to such containers, flexible containers formed in a bag shape with a synthetic resin film are in widespread use. This flexible container changes its appearance shape depending on the fluidity of its contents, has high efficiency in storing in a box, etc., and if it is only a used flexible container, its volume is small and it can be bent arbitrarily. Since they can be stacked or stacked, they are not bulky like PET bottles and are easy to handle.

  Conventionally, as an example of using a laminated film as a packaging material, for example, a packaging bag for long-term storage of drinking water described in JP-A-10-139974 and a method for producing the same (see Patent Document 2), JP-A 2000-14374 Liquid processed foods described in (see Patent Document 3) and the like. The packaging bag for long-term storage drinking water according to JP-A-10-139074 is obtained by forming an antibacterial layer on the surface of a base material composed of a laminate of a polyethylene film and a nylon film. Moreover, although the liquid processed food based on Unexamined-Japanese-Patent No. 2000-14374 is a packaging example by the laminated body of the resin film of several layers, this absorbs oxygen gas in liquid food and a head space rapidly. Therefore, it is possible to provide a liquid processed food that is excellent in durability and can be stored for a long period of time without deterioration or disappearance of aroma components.

By the way, the following points are pointed out as problems to be solved for flexible containers used for commercialization of liquids, transportation, storage and the like.
First, in order to commercialize contents such as liquid using a flexible container, and to transport and store the product, it is essential that the material has no odor. In particular, products that determine the quality of being tasteless and odorless, such as liquids, and products that deteriorate in quality due to odor adherence, require that the material of the flexible container itself be free of bromide. In addition, a plurality of flexible containers can be transported using a cardboard box or the like to the transport container. However, if the cardboard box or the like is brought into contact with the flexible container during transport or storage, the cardboard box or the like There is a risk that the odor of the liquid enters the inside of the flexible container and adheres to contents such as liquid. There is a risk that the value of a product such as a liquid that is indispensable for tasteless odor will be damaged in its commercial value, for example, the attached odor is illusioned as a taste.

  Secondly, liquids commercialized by flexible containers are delivered by truck transport, but even if cardboard boxes or the like are used as transport containers, shocks and pressures such as vibrations and drops are applied during transport and delivery. If the flexible container is damaged, the contents may leak, such as liquid leakage.

  Third, in order to prevent the contents from flowing out due to damage to the flexible container, it is necessary to increase the strength of the flexible container. However, if the strengthening hinders tearability, it is an advantage of the flexible container. There is a risk of unsealing.

  Fourth, flexible containers are easy to dispose of, but if they are made of a material that contains environmental hormones or chlorine, environmental hormones such as outflow of environmental hormones during disposal and generation of dioxins during incineration, etc. Cause.

Therefore, the present inventors have previously developed a packaging material having a three-layer structure of nylon (NY), ethylene vinyl alcohol resin (EVOH), and polyethylene (PE), and a flexible container using the packaging material.
JP-A-8-198231 Japanese Patent Laid-Open No. 10-139074 JP 2000-14374 A

  However, the flexible container made of the packaging material having this three-layer structure has an odor transferred to the contents despite the fact that an ethylene vinyl alcohol resin (EVOH) layer having gas barrier properties is arranged in the intermediate layer. There was a case. Therefore, as a result of various studies by the present inventors, when the nylon layer on the surface side of the flexible container gets wet, moisture penetrates into the EVOH layer, and when this EVOH layer gets wet, the gas barrier property is lowered and the contents are smelled. Knew that would move. In addition to the smell moving to the contents, it was found that nylon was hydrolyzed to generate caprolactam, and this caprolactam permeated the EVOH layer and dissolved in the contents, thereby deteriorating the flavor of the contents. Furthermore, EVOH has a problem that compatibility with polyethylene is poor and tearability is not always good.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a packaging material having good tearability and no odor transfer to the contents, and a flexible container using the same.

  The present invention includes a laminate comprising a heat-fusible layer having heat-fusibility, a gas barrier layer having gas barrier properties, and a protective layer having mechanical strength, and the heat-fused layer is provided on the surface of the laminate. Provided is a packaging material having a tearing property, wherein the gas barrier layer is made of an oxide-coated polyethylene terephthalate obtained by coating polyethylene terephthalate with alumina oxide. Claim 1). Alumina oxide-coated polyethylene terephthalate maintains gas barrier properties even when the protective layer gets wet and is invaded by moisture, so by using alumina oxide-coated polyethylene terephthalate as the gas barrier layer, odorous gas can reach the heat fusion layer. Never reach. It is also excellent in tearability.

  In particular, the heat-sealing layer is preferably polyethylene or other heat-fusible resin (Claim 2), and the protective layer is made of nylon, polyethylene terephthalate and biaxially oriented polypropylene. It is preferable that it is 1 or more types selected (Claim 3). Even if the nylon surface, which is the protective layer, gets wet and the nylon is hydrolyzed to caprolactam, the alumina oxide-coated polyethylene terephthalate blocks the permeation of caprolactam. The caprolactam is not detected from beverages or the like.

  Moreover, the flexible container of this invention uses the packaging material of any one of Claim 1 to 3, and made the said heat-fusion layer into the inner surface side (Claim 4). Alumina oxide-coated polyethylene terephthalate maintains gas barrier properties even when the protective layer gets wet and is invaded by moisture, so the smell does not transfer to the contents, and it is also excellent in tearability. Can be opened easily.

  In this packaging material, the inner surface of the protective layer or the gas barrier layer or both may be set on a display surface such as printing.

  The packaging material of the present invention has a gas barrier layer made of alumina oxide-coated polyethylene terephthalate, so there is no scent in the contents compared to the case of using ethylene vinyl alcohol resin, and the odor from the contents can be suppressed. In addition to preventing deterioration of the contents due to odor gas, it can be easily opened by tearing, and has excellent mechanical strength and environmental properties.

  And the flexible container using such a packaging material can enclose water, other liquids, etc., can be commercialized, and can carry and store it easily. Moreover, there is no fragrance in the water, other liquids, etc., and the odor from the contents can be suppressed, the deterioration of the contents due to the odor can be prevented, and it can be easily opened by tearing, and the mechanical strength and It is an inexpensive flexible container with excellent environmental properties.

The packaging material of this invention is used for the flexible container etc. which hold liquids, such as water, for example, the flexible material 1 shown in FIG. 1 is used.
This flexible material 1 is a laminated film composed of a plurality of layers. In this embodiment, the heat-fusible layer 2 as a base material having heat-fusibility and permeation of odor gas or the like from both the front and back sides. It is a laminate composed of a gas barrier layer 3 having a gas barrier property capable of blocking water and a protective layer 4 having an appropriate mechanical strength capable of preventing leakage of contents. The laminate constituting the flexible material 1 is formed by interposing an adhesive and an adhesive resin between the heat fusion layer 2 and the gas barrier layer 3 and between the gas barrier layer 3 and the protective layer 4. The heat-fused layer 2, the gas barrier layer 3, and the protective layer 4 are bonded together by a dry laminating process such as pressurization.

  As the heat fusion layer 2, for example, polyethylene (PE) or other resin having heat fusion property can be used. Examples of the other heat-fusible resin include polypropylene (PP), ethylene vinyl alcohol (EVA), and linear low density polyethylene (LLPE). Further, as the protective layer 4, for example, nylon (NY), polyethylene terephthalate (PET), biaxially oriented polypropylene (OPP), or the like can be used. If printing on the protective layer 4, nylon or polyethylene terephthalate is used. It is preferable to use it. In this embodiment, the gas barrier layer 3 is made of alumina oxide-coated polyethylene terephthalate (hereinafter sometimes referred to as “CPET”) obtained by coating polyethylene terephthalate with alumina oxide.

  For example, a laminate made of “NY # 15 / CPET # 12 / PE # 40” or the like can be configured as the flexible material 1 selected from these resins. Here, “NY # 15 / CPET # 12 / PE # 40” is a laminate of 15 μm thick nylon (NY), 12 μm thick alumina oxide coated polyethylene terephthalate (CPET) and 40 μm thick polyethylene (PE). Is the body.

  As shown in FIG. 2, the flexible material 1 has a sandwich structure in which the gas barrier layer 3 is sandwiched between the protective layer 4 and the heat fusion layer 2 installed on the surface layer, and the inner surface of the protective layer 4. The side is set as the printing surface and the content display 5 is provided. In this way, if the display 5 is provided on the inner surface side of the protective layer 4, the display 5 is protected by the protective layer 4, and if a transparent material is used for the protective layer 4, the function of the display 5 is not impaired. . In the present embodiment, the inner surface side of the protective layer 4 is set as a printing surface, and “mineral water” is displayed on the inner surface side of the protective layer 4, but the protective layer 4 side of the gas barrier layer 3 is printed on the printing surface. May be set.

  Such a flexible material 1 has a heat fusion property, a gas barrier property, and an abrasion resistance by a three-layer structure, and also has a tear property and an odorless property. Here, the heat-fusible property refers to a property of fusing by heating the heat-fusible layer 4 side to each other. Further, the gas barrier property means a property capable of blocking the permeation of gas such as odor gas. If the flexible container is formed from the flexible material 1 having the gas barrier property, the contents of the flexible container are included. No odor is produced and the odor generated from the contents can be blocked. Furthermore, tearability means a property that, when a cut is formed in a flexible container, for example, can be easily torn and opened from the cut, and odorless means odor from the heat-sealing layer 4 or the flexible material 1. The property that does not occur.

  If a pure polyethylene (PE) film is used for the heat-fusible layer 2 that is a base material, even if water or the like that comes in contact with the polyethylene (PE), a plastic odor or the like is transferred to the water or the like. In addition, the content can be made non-brominated and the content can be prevented from deteriorating due to odor. Moreover, the heat-sealing layer 2 side is adhered and heated from the protective layer 4 side, whereby the heat-sealing layer 2 can be easily fused, and a sealed state that can block water or the like is obtained. .

  Moreover, since the oxide barrier-coated polyethylene terephthalate (CPET) is used for the gas barrier layer 3, the gas barrier layer 3 can block external odor gas that has entered from the protective layer 4 side. Therefore, the odor gas does not reach the heat-fusible layer 2, and the water or the like as the contents is not contaminated with the odor gas. In the CPET film, an alumina oxide layer is formed by coating on the surface layer as a reinforcing layer that blocks gas, and this alumina oxide layer is previously coated on the PET film.

  Further, if nylon (NY) is used for the protective layer 4, the mechanical strength can be increased, and perforation or the like in the heat fusion layer 2 and the gas barrier layer 3 as the base material can be reliably prevented. When nylon (NY) is used for the protective layer 4, when nylon (NY) gets wet with water, caprolactam is generated by hydrolysis of nylon, and moisture that has absorbed the generated caprolactam reaches the gas barrier layer 3 However, caprolactam is not mixed into the contents by using CPET for the gas barrier layer 3.

  If a resin such as pure nylon, polyethylene terephthalate, or polyethylene is used as the protective layer 4, the gas barrier layer 3, and the heat fusion layer 2, these resins do not contain environmental hormones or chlorine, so that they are flexible. Even if the sex material 1 is discarded, environmental hormones do not flow out, and even if disposed of by incineration, no dioxins are generated, and the environment is not deteriorated.

Next, a flexible container using a flexible material as the packaging material of the present invention will be described.
As shown in FIG. 3, the flexible container 11 of the present embodiment is wound with the flexible material 1 described above so that the heat-fusible layer 2 is inside, and the both ends are stacked and sealed. The ridge lines 14 and 15 are formed by being folded so as to be the center, the center seal portion 12 is formed, and the upper end is sealed to form the top seal portion 13.

  Then, on the corner portion side of the top seal portion 13, an opening position is shown corresponding to the display 5, and incisions 16 and 17 are formed as tearing portions for easy opening.

  Thus, the accommodating part A closed by two places, the center seal part 12 and the top seal part 13, comprises the flexible container 11 in the state opened by the bottom seal part 18 not being formed. Therefore, with the opening 19 side of the flexible container 11 facing upward, water is loaded by water loading means (not shown), and the gas is discharged from the housing portion A, and the bottom seal portion 18 is sealed in the same manner as the top seal portion 13. Then, the liquid filling and the sealing process are completed.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to the following Example at all.

[Example 1]
The flexible container 11 shown in FIG. 3 is formed using a NY # 15 / CPET # 12 / PE # 40 film composed of a 15 μm thick NY film, a 12 μm thick CPET film, and a 40 μm thick PE film. Then, after the tasteless and odorless mineral water was loaded into the housing part A, the bottom seal part 18 was sealed.

[Comparative Example 1]
The flexible container 11 shown in FIG. 3 is formed using a NY # 25 / EVOH # 12 / PE # 40 film composed of a 25 μm thick NY film, a 12 μm thick EVOH film, and a 40 μm thick PE film. Then, after the tasteless and odorless mineral water was loaded into the housing part A, the bottom seal part 18 was sealed.

  About these Example 1 and Comparative Example 1, performance comparison (a strength test, a fragrance test, a tearability test) was performed from the viewpoints of liquid commercialization, quality maintenance, transportability, storage property, and the like.

(1) Strength test In the strength test, the flexible container 11 filled with mineral water and sealed is stored in a cardboard case, and the cardboard case is dropped 40 times from a height of 30 cm onto the concrete floor, and the flexible container 11 It was tested whether or not water leaked from. The test results are shown in Table 1.

  As shown in Table 1, the flexible container 11 according to Example 1 did not leak, but the flexible container 11 according to Comparative Example 1 leaked water in two out of twenty containers. From this, it was confirmed that the flexible container 11 according to Example 1 has higher strength than the flexible container 11 according to Comparative Example 1.

(2) Transfer incense test In the transfer incense test, the flexible container 11 does not feel the film odor during manufacture, that is, it is odorless, and the corrugated cardboard paper that is the material of the corrugated cardboard case is moistened. 11 was wrapped with a wrap, stored in a thermostatic bath at 35 ° C. for 2 weeks, and a test was conducted to confirm that there was no scent in the mineral water in the flexible container 11. In the test, the odor of mineral water in the flexible container 11 is smelled, and “smells with the same scent as the blank (E: Excellent)” and “smells different from the blank, but good (G: “Good” ”,“ There is a moving incense but can be drunk (F: Fair) ”and“ No migrant incense and cannot be drunk (NG: No Good) ”. The results are shown in Table 2.

  As shown in Table 2, in the flexible container 11 of Comparative Example 1, fragrance was generated in the mineral water as the contents, but in the flexible container 11 of Example 1, there was no fragrance and the quality of the mineral water at the time of loading was improved. Both were retained and good taste was obtained. E indicates the highest rank.

(3) Tearability test The tearability test examined the difficulty when opening using the cut 17 formed in the flexible container 11. In this case, 6 inspectors gave a rating with a maximum of 3 points, and the total score was taken as the score. Specifically, the score is 3 points if it is good, 2 points if it gets stuck slightly but it cuts cleanly, 1 point if it is unpleasant, such as the need for opening, and 0 point if it does not cut well. A scoring system was used for scoring. The test results are shown in Table 3.

  As shown in Table 3, it was confirmed that the flexible container 11 according to Example 1 has higher tearability than the flexible container 11 according to Comparative Example 1 and can be easily cut from the cut end 17. It was.

It is the perspective view which notched and showed a part of flexible material which is one Embodiment of the packaging material of this invention. It is an expanded sectional view which shows the II-II line cross section of FIG. It is a top view which shows the flexible container which concerns on one Embodiment of this invention.

Explanation of symbols

1 Flexible material (packaging material)
2 Heat-fusion layer 3 Gas barrier layer (CPET)
4 Protective layer 5 Display 11 Flexible container

Claims (5)

A laminate comprising a heat-fusible layer having heat-fusibility, a gas-barrier layer having gas barrier properties, and a protective layer having mechanical strength, and the heat-fused layer is exposed on the surface of the laminate. A packaging material having tearability,
The packaging material according to claim 1, wherein the gas barrier layer is made of an alumina-coated polyethylene terephthalate in which polyethylene terephthalate is coated with alumina oxide.   The packaging material according to claim 1, wherein the heat-fusible layer is polyethylene or other resin having heat-fusible properties.   The packaging material according to claim 1 or 2, wherein the protective layer is at least one selected from the group consisting of nylon, polyethylene terephthalate, and biaxially oriented polypropylene.   A flexible container using the packaging material according to claim 1, wherein the heat-fusible layer is on the inner surface side. The flexible container according to claim 4, wherein the packaging material is configured such that a surface on the inner surface side of the protective layer or the gas barrier layer or both are set on a display surface such as printing.

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