JP2001335078A - Three-way-sealed packaging bag having gas barrier properties - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pillow-shaped, three-way-sealed packaging bag excellent in gas barrier properties, which is made by using a packaging material having a simple layer structure. SOLUTION: A base film 11 having a heat seal layer is laminated on a metallic vapor-deposited sealant film 12 in such a manner that a base layer face of the base film 11 and a metallic vapor-deposited layer face of the sealant film 12 are opposed to each other with an adhesive layer 13 interposed therebetween, thereby forming a laminated film 10 composed of two layers. The three-way-sealed packaging bag, which is of an envelope-sealing type and has gas barrier properties, is made by folding the laminated film 10 so that the sealant layer forms an inner face of the bag.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-layer sealed packaging bag having a two-layer barrier property suitable for packaging relatively lightweight dry foods such as snack foods such as potato chips containing fats and oils. The present invention relates to a three-sided seal packaging bag having a two-layered envelope-attached barrier property.

[0002]

2. Description of the Related Art Snack foods such as potato chips and dried noodles such as instant noodles are dry foods containing a large amount of fats and oils. Such dried foods lose their original aroma when they absorb moisture. Irradiation of the dried food with ultraviolet light or visible light in the presence of oxygen causes decomposition (oxidation) of fats and oils. As a result, the flavor, aroma, and the like of these dried foods are impaired.

[0003] Accordingly, packaging materials used for packaging such dried foods are required to have high oxygen barrier properties, water vapor barrier properties, and light shielding properties. Under such demands, [outside] biaxially oriented polypropylene (0PP) film / polyethylene (P
E) / Polyethylene terephthalate (VMPET) film with aluminum (Al) deposited on one side / PE /
Laminated materials composed of a five-layer structure composed of an unstretched polypropylene (CPP) film [inside] have been used very often.

[0004] As a packaging form, FIG.
As shown in (b), the same film surfaces are opposed to each other and sealed in a sleeve shape at the center (back seal), and the back seal portion of the sleeve-shaped film is turned sideways to seal the upper and lower ends. Very many types of packaging called pillow packaging bags have been used.

The packaging material having the five-layer structure is excellent in oxygen barrier property, water vapor barrier property and light-shielding property. However, in addition to the complicated layer structure and relatively high cost, recent problems are as follows. Further simplification is required in connection with the Packaging Containers Recycling Law.

In order to meet these requirements, a barrier coat layer is provided on the OPP surface of an OPP film provided with a heat seal layer, and a CPP film is formed by depositing Al on one side of the barrier coat layer. There is a three-sided seal packaging bag of a two-layered seal type in which a two-layer laminated material in which the surfaces are opposed to each other is produced, and the CPP surfaces of the laminated material are opposed to each other and sealed in a sleeve shape at the center.

[0007] However, in this packaging bag, although the layer structure is simplified, when the bag is formed, the back seal portion is turned sideways, so that cracks are easily generated from the bent back seal portion, and the barrier property is reduced. However, there still remains a problem that is reduced.

[0008]

SUMMARY OF THE INVENTION The present invention has been made by paying attention to the above-mentioned problems and demands concerning a three-sided seal packaging bag of a gas-stick type, which is a pillow packaging bag for packaging dry food such as snacks. It is an object of the present invention to provide a pillow-shaped three-side sealed packaging bag having excellent gas barrier properties using a packaging material having a simple layer structure.

[0009]

According to a first aspect of the present invention, there is provided an adhesive having a heat-sealing layer and a base material layer surface of a base film having a heat-sealing layer and a metal deposition layer surface of a metal-deposited sealant film facing each other. This is a three-sided seal packaging bag having a barrier property of an envelope-attached type, in which a laminated film having a two-layer structure in which layers are interposed is folded so as to have a sealant layer on the inner surface and made into a bag.

As described above, since the back seal portion of the three-side seal packaging bag of the present invention has an envelope-attached structure, the sealant film portion of the laminated film constituting the bag may be bent by 360 °. No cracks are generated from the bent portion.

[0011] The invention of claim 2 provides a barrier between the base layer of the base film having the heat seal layer and the metal deposition layer of the sealant film provided with the metal deposition layer. It is a three-side seal packaging bag having a barrier property, which is provided with a coat layer.

As described above, the barrier coat is formed between the surface of the base film of the base film having the heat seal layer of the laminated film used for the packaging bag and the metal vapor deposited layer of the sealant film provided with the metal vapor deposited layer. Since the layers are provided, the two-layer film can obtain higher oxygen gas barrier properties.

[0013]

Embodiments of the present invention will be described below. As shown in FIGS. 1 and 2, for example, the three-side sealed packaging bag having a barrier property according to the present invention includes a base material layer 11a surface of a base film 11 having a heat seal layer 11b, and a sealant film 12 on which metal deposition is performed. The laminated film 10 having a two-layer structure in which the metal vapor-deposited layer 12b is opposed to the surface of the metal-deposited layer 12b and an adhesive layer 13 is interposed therebetween is folded so that the sealant film 12 is on the inner surface, and the envelope is attached. It is a packaging bag.

Since the base film 11 is heat-sealed with a sealant layer film 12 to be described later by a bag making and filling machine or the like, heat sealing is required. Therefore, a heat seal layer 11b is formed on the base material layer 11a. I do.

The base material layer 11a may include various resin films used as a base material film. An example of such a resin film is an OPP film.

The heat seal layer 11b is made of a known heat seal lacquer obtained by appropriately dissolving an ethylene / vinyl acetate copolymer resin, a chlorinated polypropylene resin, a urethane resin or the like with a solvent and forming the lacquer by a known gravure coating method or the like. What is necessary is just to form by apply | coating to the base material layer 11a by an application method. In this case, the coating amount is 1 to 4 g.
/ M ² is an appropriate amount.

The substrate film 11 can be replaced by a commercially available heat-sealable OPP film. In this case, the base film becomes the base layer 11a.

The thickness of the base film 11 is 20 to 30 μm
It is preferred that it is about. When the thickness of the base film is within this range, it is possible to obtain a feeling and a waist suitable for a packaging bag having barrier properties.

The sealant film 12 has a metal deposition layer 12b on the sealant layer 12a in order to improve the barrier property.
Is formed.

The sealant layer 12a includes a PE film, a CPP film,
PET film and the like can be mentioned. Above all, CP
P film can be used preferably. Sealant film 1
The thickness of 2 is preferably about 30 to 60 μm. When the thickness of the sealant film is within the above range, it is possible to obtain a feeling and a waist suitable for a packaging bag having barrier properties.

A metal deposition layer 12b is provided on one surface of the sealant layer 12a. This metal deposition layer can be formed by depositing a metal such as aluminum or magnesium on the sealant layer, and the light shielding property and
Provides oxygen barrier properties and water vapor barrier properties.

The substrate film 11 and the sealant film 12 are dry-laminated with the adhesive layer 13 interposed between the substrate layer 11a of the substrate film 11 and the metal deposition layer 12b of the sealant film 12. And the like. The adhesiveness between the base film 11 and the sealant film 12 is improved by interposing the adhesive layer 13.

The adhesive layer 13 can be formed using, for example, a two-part curable polyurethane adhesive such as a mixture of a polyester or polyether compound and an isocyanate compound. The amount of adhesive applied is 1 to
It is preferably about 5 g / m ² .

In order to further improve the oxygen barrier properties of the laminated film, the heat seal layer 11b of the base film 11
The barrier coat layer 14 is formed on the surface on which the metallization layer 12 is not formed.
b may be laminated with the adhesive layer 13 interposed therebetween (see FIG. 3).

The barrier coat layer 14 is a layer having an oxygen barrier property, and contains a resin having an oxygen barrier property and an inorganic layered compound. By providing the barrier coat layer 14, the fragrance retention of the laminated film can be enhanced.

Examples of the inorganic layered compound include clay minerals such as a kaolinite group, a smectite group, and a mica group. Among them, it is preferable to use a smectite group such as montmorillonite, hectorite, and saponite. These inorganic stratiform compounds take in other resin components and the like between the layers, and easily form a complex. Particularly, montmorillonite is more preferably used because montmorillonite is excellent in stability in a solution state and coating state.

The resin contained in the barrier coat layer 14 is
Although it is not particularly limited as long as it is easily taken in between the layers of the inorganic layered compound, it is preferable to use a water-soluble polymer. Examples of the water-soluble polymer include polyvinyl alcohol (PVA), polyvinylpyrrolidone, starch, methylcellulose, carboxymethylcellulose, sodium alginate, and acrylic resin. In particular, when PVA is used, the highest gas barrier properties can be obtained.

The PVA referred to herein is obtained, for example, by saponifying polyvinyl acetate, from partially saponified PVA in which acetic acid groups remain to tens of percent to completely saponified PVA in which only a few percent of acetic acid groups remain. Including.

The barrier coat layer 14 preferably contains a hydrolysis / polycondensation product of a metal alkoxide.
This metal alkoxide has a structure in which M is a metal, R is an alkyl group,
When n is the coordination number of an alkoxy group, the general formula M (O
R) A compound represented by _n . M is Si, Ti, Al
And Zr, and R is preferably selected from a methyl group and an ethyl group. In particular, the use of tetraethoxysilane [Si (OC ₂ H _{5) 4]} and triisopropoxyaluminum _{[Al (O-2'-C 3} H 7) 3 ] and the like, alkoxides of hydrolysis products, the aqueous It is preferable because it exists relatively stably in the solvent. These metal alkoxides can be used as a mixture.

The barrier coat layer 14 is 10 to 90% by weight.
It is preferable to contain the inorganic layered compound of the above and 10 to 90% by weight of a resin. In the laminated film, the barrier layer preferably contains 10 to 90% by weight of a hydrolysis / polycondensation product of a metal alkoxide.

[0031] The barrier coating layer 14 is in a dry state, it is preferable to form a coating amount of 0.01 to 2.0 g / m ^2, formed by a coating amount of 0.2-0.4 g / m ² Is more preferable. When the barrier coat layer 14 is formed thick, higher oxygen barrier properties can be obtained.
However, when the barrier coat layer 14 is formed with a thickness exceeding the upper limit, cracks occur in the barrier coat layer 14, and furthermore, it takes a long time to dry it.
That is, there is a possibility that the workability is reduced. Also,
If the thickness of the barrier coat layer 14 is less than the lower limit, sufficient oxygen barrier properties may not be obtained.

The laminated film 10 thus produced
From, using a generally known bag making and filling machine with the sealant film 12 inside, for example, using a vertical bag making and filling machine,
As shown in FIGS. 1A and 1B, an envelope-attached three-side seal packaging bag was produced. In this case, the back seal portion 21
Since the heat seal layer 11b of the base material film 11 and the sealant layer 12a of the sealant film 12 overlap each other, the laminated film of the back seal portion may be bent as in the conventional jointed palm type. Therefore, there is no danger of cracks occurring in the back seal portion, and the gas barrier property does not decrease.

[0033]

EXAMPLES Examples of the present invention will be described below more specifically. <Example 1> As a substrate film 11, a heat seal type OPP film (trade name: HC-
OP (manufactured by Tosero Corporation) was prepared. The sealant film 12 has a thickness of 4 with Al deposited on one side.
A 0 μm VMCPP film (trade name; CP WA, manufactured by Tosero Corporation) was prepared.

Next, the base layer 11a of the base film 11
The base film 11 and the sealant film 12 are laminated by a dry lamination method with the surface facing the metal vapor deposition layer 12b of the sealant film 12 and a two-component curing type polyurethane adhesive interposed as an adhesive layer 13. And a laminated film 10. The amount of adhesive applied was 1.5
g / m ² .

Finally, the laminated film 10 slit to an appropriate width is set in a vertical bag making and filling machine, and is filled with contents such as snacks and the like, length: 180 mm, width: 1
35mm, back seal width; 10mm, top seal width; 1
An envelope-attached three-sided seal packaging bag of Example 1 having a dimension of 0 mm and a ground seal portion width of 10 mm was produced.

Example 2 Base Layer 1 of Base Film 11
Except that the following barrier coat layer 14 was provided on the 1a surface,
A laminated film was produced in the same manner as in Example 1, and then an envelope-attached three-side sealed packaging bag of Example 2 having the same dimensions as Example 1 was produced.

The method for preparing and applying the barrier coat layer 14 is as follows. That is, first, a coating solution A was prepared by mixing montmorillonite with a 5% by weight aqueous solution of PVA so that the weight ratio of PVA to montmorillonite was 1: 1.

Next, a coating solution A is applied to the surface of the base material layer 11a of the base film 11 using a bar coater.
At a temperature of 1 minute to form a barrier coat layer 14 having a thickness of 0.5 μm.

Example 3 An OPP film having a thickness of 20 μm (trade name: U-1, manufactured by Tosello Co., Ltd.) was prepared as a base material layer 11a serving as a base of the base film 11, and one side of this OPP film was prepared. Then, a heat seal lacquer mainly composed of an ethylene / vinyl acetate copolymer resin was applied by a gravure coating method to form a heat seal layer 11b having a coating amount of 2 g / m ² .

Next, a 0.5 μm-thick barrier coat layer 14 similar to that of Example 2 was formed on the surface of the OPP film on which the heat seal layer 11b was not formed.
Lastly, the surface of the base film on which the barrier coat layer 14 was formed and the sealant film 1 in the same manner as in Example 1.
The metal film 12b of the VMCPP film having a thickness of 40 μm, which is 2, is opposed to the surface thereof, and a two-component curable polyurethane adhesive is interposed as the adhesive layer 13 to form the base film 1
1 and a sealant film 12 were laminated by a dry lamination method to obtain a laminated film 10. The amount of the adhesive applied was 2.0 g / m ² .

The laminated film was slit into an appropriate width, and an envelope-attached three-side sealed packaging bag was prepared with the sealant layer 12 on the inner surface in the same manner as in Example 1 to obtain a packaging bag of Example 3.

<Reference Example 1> As a reference example, [outside] OPP film (20 μm thick) / PE (13
μm thickness) / VMPET (12 μm thickness) / PE (13 μm
Thickness) / CPP (18 μm thickness) [Inside] Using a five-layer film having the configuration, a three-sided seal packaging bag of a palm joint type of Reference Example 1 was produced.

The breaking strength, oxygen permeability and water vapor permeability of the three types of packaging bags prepared in Example 3 were measured and evaluated by the following methods. Table 1 shows the results. For the packaging bag of Reference Example 1, only the oxygen permeability and the water vapor permeability were measured. How to measure the bag breaking strength さ Avoid sticking the seal on the packing bag, pierce the needle, and slowly inject air. Although the internal pressure gradually increased, air was continuously injected until the bag was broken, the pressure at the time of the bag breaking was measured, and the bag breaking point was confirmed. Oxygen permeability measurement method に よ る According to JIS K7126 B method (isobaric method). Water vapor permeability measurement method ‥ According to JIS K7129 B method (infrared sensor method).

[0044]

[Table 1]

Thus, it can be seen that the three types of packaging bags of Example 3 have no tear from the back seal portion and have no problem in strength. However, since there is a possibility that the end face of the laminated film may directly touch the contents in the portion where the envelope is attached, it is necessary to sufficiently take measures such as protecting the end face with a tape or the like in advance.

[0046]

As described above, the three-side sealed packaging bag of the present invention has a simplified layer structure and is less likely to crack from the back seal portion, and is suitable for light-weight dried foods such as snacks. It is a three-sided seal packaging bag having excellent barrier properties.

[Brief description of the drawings]

FIG. 1 is an explanatory plan view showing an example of a three-side seal packaging bag having a barrier property of the present invention, and FIG. 1 (b) is an explanatory sectional view taken along line AA ′ of FIG.

FIG. 2 is a cross-sectional explanatory view showing an example of a laminated film used for a three-side seal packaging bag having a barrier property of the present invention.

FIG. 3 is an explanatory cross-sectional view showing another example of a laminated film used for a three-side seal packaging bag having a barrier property of the present invention.

4A and 4B show an example of a conventional three-side seal packaging bag having barrier properties. FIG. 4A is an explanatory plan view, and FIG.
FIG. 4 is a sectional view taken along line AA ′ of FIG.

[Explanation of symbols]

 10, 15 {Laminated film 11} Base film 11a {Base layer 11b} Heat seal layer 12} Sealant film 12a {Sealant layer 12b} Metal deposition layer 13} Adhesive layer 14} Barrier coat layer 20 {Three-sided seal packaging bag 21} Back seal part (envelope-attached type) 22 {Top seal part 23} Ground seal part 50 {Three-sided seal packaging bag 51} Back-seal part (two-sided seal type) 52} Top seal part 53 ‥‥ Ground seal part

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3E064 AA09 BA16 BA22 BA30 BB03 BC08 BC14 EA18 FA01 HN05 3E067 AA11 AB01 BA20A BB11A BB14A BB16A BB25A BB26A CA05 CA06 CA12 EA08 FB07 FC01 GD02 3A0BA02BA03 4F100 AB01C AB10C AK01A AK07B AK07C AT00B BA02 BA03 BA16 CB00 EH66C EJ38B EJ38C GB16 GB23 JD01 JD01 JD03 JK01

Claims (2)

[Claims] 1. A laminate in which a base material layer surface of a base film having a heat seal layer and a metal deposition layer surface of a metal-deposited sealant film face each other with an adhesive layer interposed therebetween.
A three-sided seal packaging bag having a barrier property of an envelope-attached type, in which a laminated film having a layer configuration is folded so that the sealant layer is on the inner surface and the bag is made. 2. A method according to claim 1, wherein a barrier coat layer is provided between the base material surface of the base film having the heat seal layer and the metal vapor deposition layer of the sealant film provided with the metal vapor deposition layer. The three-side-sealed packaging bag having a barrier property according to claim 1.