JPH0669146U - Double bag - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a double bag with little impact on the scent components and active ingredients of the contents, without the risk of the contents being altered or having an offensive odor, and having good impact resistance. . [Structure] The double bag 1 comprises 1,4-glycol components.
A double film 10 in which a polyethylene film 9 is laminated on the outside of a composite film 8 having a three-layer structure in which a polyester resin layer 5 containing butanediol as a main component, a stretched nylon film 6 and a polyethylene film 7 are laminated together Is placed inside, and the heat-sealing portion 2 in the periphery is heat-sealed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a so-called bag-in-box plastic bag in which a plastic bag is contained as an outer box, which is a corrugated cardboard box used as a container for large-scale liquids. It is about heavy bags.

[0002]

[Prior art]

 Such a bag-in-box type container is composed of an outer box and an inner bag, and since each of these characteristics can be utilized, it has many advantages in transportation and use.

[0003] For example, since it can be folded when the contents are not filled, it is easy to transport without being bulky, so that transportation costs can be reduced.

Further, since it is not necessary to collect the container after use, labor can be saved.

The material of the inner bag can be selected according to the contents, and the contents can be stored for a long time.

By the way, as a material for such an inner bag, a composite film using a polyolefin resin such as polyethylene or polypropylene has been often used conventionally.

[0007] For example, Japanese Utility Model Publication No. 58-56184 discloses a double-layered film in which a polyethylene film is laminated on both sides of a polyethylene film on both sides of a nylon film on one side of which aluminum is vapor-deposited. A double bag is described in which the composite films are laminated inside and heat-sealed around the periphery.

[0008]

[Problems to be Solved by the Invention] However, in the case of the double bag as described above, since the innermost layer in direct contact with the content is a polyethylene film, when the content is, for example, juice, its scent component, When the content is, for example, a detergent or a seasoning, the active ingredient is largely adsorbed, and further, low molecular weight components such as olefin odors are often eluted, which causes a change in taste and a bad odor.

The present invention has been made in view of the above-mentioned conventional drawbacks, and an object thereof is to reduce the aroma component of the contents, the adsorption of the active ingredient, etc., and to prevent the contents from being altered or having an offensive odor. Another object is to provide a double bag having good impact resistance.

[0010]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a double bag in which at least one base film consisting of a film or a sheet and two base films are superposed and heat-sealed around the contents. The feature is that a polyester resin layer containing 1,4-butanediol as a main component as a glycol component is provided in the innermost layer in contact with.

Further, the above-mentioned 1,4-butanediol is characterized by being contained in at least 50 mol% or more in all glycol components.

Further, the above polyester-based resin is characterized in that it contains at least 10 mol% of an aliphatic dicarboxylic acid as an acid component.

The present invention will be described in more detail below.

FIG. 1 is a sectional view showing an example of the structure of a double bag according to the present invention.

As shown in the figure, the double bag 1 includes a double-layered film 10 in which a single layer, for example, a polyethylene film 9 is stacked on the outer side of a three-layered composite film 8 with the composite film 8 inside. In addition, the heat seal portion 2 around the heat seal is performed. Although the spout 4 is provided in a part of the body 3, whether or not such a spout 4 is provided is arbitrary. In the innermost layer of the composite film 8 in contact with the contents, a polyester resin layer 5 containing 1,4-butanediol as a main component as the glycol component is provided. And a polyethylene film 7 are attached. The polyethylene film 7 is provided for heat sealing with the outer polyethylene film 9. In addition, aluminum may be vapor-deposited on the surface of the stretched nylon film 6 or an aluminum foil may be laminated on the surface of the stretched nylon film 6 in order to block light transmission and prevent deterioration of the contents due to light.

The polyester resin used in the present invention contains 1,4-butanediol as a main component in the glycol component, but it should be used by mixing with other diols such as ethylene glycol and neopentyl glycol. You can In this case, it is desirable that the main component, 1,4-butanediol, be contained in an amount of at least 50 mol% or more in all glycol components. If it is less than 50 mol%, the flexibility of the resin produced will deteriorate and the impact resistance will deteriorate.

An aliphatic dicarboxylic acid is preferably used as the acid component of the polyester resin. Specific examples of the aliphatic dicarboxylic acid compound include glutaric acid, adipic acid, azelaic acid and sebacic acid. Further, the above aliphatic dicarboxylic acid must be contained in at least 10 mol%, preferably 20 mol% in the total acid component, and the same type of compound may be used alone, or different types of compounds may be mixed and used. May be. The dibasic acid that can be used in combination with the above aliphatic dicarboxylic acid as the acid component is not particularly limited, and for example, aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid can be used.

The above polyester-based resin can be easily obtained by using a known polyester resin synthesizing means.

The thickness of the polyester resin layer used in the present invention is preferably about 60 to 80 μm in the case of a single layer film, and about 40 to 60 μm in the case of forming a composite film as shown in FIG.

The above polyester-based resin is less likely to adsorb a scent component, an effective component and the like, is free from the risk of a change in the content of the product and an offensive odor, and has good impact resistance.

The other layer structure of the composite film 8 is not limited to the above-mentioned layer structure as long as the innermost layer is the above polyester resin layer. For example, polyethylene or polypropylene may be formed on the polyester resin layer. Polyolefin resin, such as polyvinyl chloride, polystyrene, polycarbonate, polyamide, and other commonly used stretched or unstretched resin layers, polyvinylidene chloride, polyvinyl alcohol, polyacrylonitrile, etc. Excellent resin layer, metal foil, thin film layer of metal or metal oxide, inorganic oxide or inorganic compound, and paper, nonwoven fabric, etc. used individually or in multiple layers according to purpose It is possible.

Further, since the composite film 8 is heat-sealed with the outer polyethylene film 9, the outermost layer of the composite film 8 is a polyethylene film that can be heat-sealed. If the outside is a film other than polyethylene, a heat-sealable film is used.

Further, the double bag of the present invention may have a layered structure as shown in FIG. That is, the inside of the double film, which is in contact with the contents, is the single-layer polyester resin layer 11, and the outside thereof is the three-layer composite film 15. Such a composite film 15 is obtained by laminating polyethylene films 12 and 14 on both sides of a stretched nylon film (or a stretched nylon film having aluminum vapor deposited on the surface or laminated with aluminum foil) 13. Of course, the layer structure is not limited to such a layer structure, and the layer structure is arbitrary according to the purpose. In the above layer structure, the polyester resin layer 11 on the inside and the polyethylene film 12, which is the innermost layer of the composite film 15 on the outer side, can be heat-sealed well during bag making. It is preferable that a polyethylene film is laminated on the layer 11 via an adhesive layer. Alternatively, a polyester film such as PET may be attached to the innermost layer of the outer composite film 15, for example, the innermost layer of the polyethylene film 12.

Further, in order to form the composite films 8 and 15 as described above, a Nilam method may be used, or a dry lamination method using an adhesive may be used, and the method is not particularly limited.

Further, as described above, in the layer structure shown in FIGS. 1 and 2, among the double films constituting the double bag, one is a single layer film and the other is a composite film. However, the double bag of the present invention has a layer structure in which the innermost layer in contact with the contents is the polyester resin layer, even if both inside and outside of the double film are single-layer films. It does not matter, and it does not matter if these are composite films.

[0026]

[Action]

 In the double bag of the present invention, the polyester resin layer containing 1,4-butanediol as the main component as the glycol component is the innermost layer in contact with the contents, so that the fragrance components of the contents and the adsorption of the active ingredients can be absorbed. In addition, since there is little elution of low molecular weight components such as olefinic odor, there is no risk of the contents changing or giving off a strange odor, and the impact resistance is also good.

[0027]

【Example】

 Hereinafter, the present invention will be described more specifically with reference to examples.

Example 1 80 parts by weight of terephthalic acid and 20 parts by weight of sebacic acid were used as acid components, and 1,4-butanediol was used as a glycol component, and copolymerization was carried out by ordinary esterification and polycondensation reaction. Polyester resin A was obtained.

Further, using 55 parts by weight of terephthalic acid and 45 parts by weight of adipic acid as the acid component and 1,4-butanediol as the glycol component, a copolyester resin B was obtained in the same manner as above.

Each of the polyester resins A and B was formed into a film having a thickness of 30 μm, and a polyethylene film having a thickness of 45 μm was attached to the surface thereof by dry lamination.

On the other hand, a polyethylene film having a thickness of 60 μm, a stretched nylon film having a thickness of 15 μm and a polyethylene film having a thickness of 55 μm are sequentially dry-laminated with an adhesive to prepare a composite film, and the composite film, the polyester resin film and the polyethylene film. A double film in which laminated films made of films are laminated with the polyethylene film inside, and the polyester resin film is laminated inside to form a double bag with a size of 485 x 478 mm. Then, 10 liters of mineral water was filled and sealed. Here, a double bag made of the above-mentioned copolymer polyester resin A film is referred to as Invention A, and a double bag made of the above-mentioned copolymer polyester resin B film is referred to as Invention B. .

For comparison, a double bag was prepared in the same manner except that a polyethylene film having a thickness of 75 μm was used in place of the laminated film made of the polyester resin film and the polyethylene film inside the double bag. This was filled with 10 liters of mineral water and sealed as described above.

After storing these for 1 week, they were opened and subjected to a sensory test, and 9 out of 10 people found that the double bag of the present invention A / B had a better taste than the comparative double bag. I got the answer.

Example-2 Each of the double bags of the inventions A and B prepared in Example-1 and the double bag for comparison were filled with drinking water containing limonene, sealed, and stored for 170 hours or more. Then, the drinking water was taken out, limonene adsorbed in each double bag was extracted with a fixed amount of ethyl acetate, and limonene in the solution was measured by gas chromatography.

As a result, the comparative double bag has a limonene adsorption amount of 100 mg / g, whereas the double bag of the present invention A has a limonene adsorption amount of 30 mg / g, and the double bag of the present invention B has a limonene adsorption amount. The amount of adsorption was 60 mg / g, and it was found that the double bag of the present invention has less adsorption of the scent component of the contents.

Example-3 Each of the double bags of the inventions A and B prepared in Example-1 and the double bag for comparison were filled with water and sealed, and then dropped from a height of 30 cm onto a concrete surface. The number of drops until the bag was broken was measured. This test was repeated 3 times and the results are shown in Table 1.

[0037]

[Table 1] Although the double bag of the present invention has a little inferior impact resistance as compared with the comparative double bag, it is at a level where there is no problem in practical use, and it can be said that the impact resistance is good.

Example 4 A polyethylene film having a thickness of 35 μm was dry laminated on one surface of a stretched nylon film having a thickness of 15 μm with an adhesive, and then a film having a thickness of 60 μm was applied to the other surface of the stretched nylon film. A polyester resin film having the same composition as the copolyester resin prepared in step 1 was dry laminated with an adhesive to produce a composite film. Then, a double film in which a polyethylene film having a thickness of 75 μm was laminated on the polyethylene film side of the composite film was laminated with the composite film inside (that is, the polyester resin film of the composite film was the innermost layer), and Example-1. Similarly, a double bag (invention) having a size of 485 × 478 mm was produced.

A double bag (comparative) was manufactured in exactly the same manner except that a polyethylene film having a thickness of 60 μm was used instead of the polyester resin film of the above composite film.

A taste sensory test, a limonene adsorption test, and a drop test were carried out in the same manner as in Example-1 to Example-3 using the double bag of the present invention and the comparative double bag. The double bag of No. 2 gave good results in all tests.

[0041]

[Effect of device]

 As described above in detail, according to the double bag of the present invention, the innermost layer in contact with the contents is provided with the polyester resin layer containing 1,4-butanediol as a glycol component as a main component. There is little adsorption of scent components and active ingredients of the contents, which was a problem with double bags, and there is no elution of low molecular weight components that cause odor of olefins, etc. It has an excellent effect that there is no Further, the double bag of the present invention has good impact resistance, which is required for practical use.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration example of a double bag according to the present invention.

FIG. 2 is a cross-sectional view showing another structural example of the double bag according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Double bag 2 Heat seal part 3 Body part 4 Spout 5 Polyester resin layer 6 Stretched nylon film 7 Polyethylene film 8 Composite film 9 Polyethylene film 10 Double film 11 Polyester resin layer 12 Polyethylene film 13 Stretched nylon film 14 Polyethylene Film 15 Composite film

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Creator Koji Kageyama 1-5-1 Taito, Taito-ku, Tokyo Inside Toppan Printing Co., Ltd. (72) Creator Hisayuki Naito 55 Ujiinzan, Uji-shi, Kyoto (72) Creator Masuo Murakami 55 Ujiinzan, Uji City, Kyoto Prefecture

Claims (3)

[Scope of utility model registration request] 1. A double bag formed by stacking two double films, which are two base films made of at least one film or sheet, and heat-sealing the surroundings,
1,4 as glycol component in the innermost layer that contacts the contents
A double bag comprising a polyester resin layer containing butanediol as a main component. 2. The double bag according to claim 1, wherein the 1,4-butanediol is contained in an amount of at least 50 mol% or more in all glycol components. 3. The double bag according to claim 1, wherein the polyester resin contains at least 10 mol% of an aliphatic dicarboxylic acid as an acid component.